QEMU QMP Reference Manual¶

Introduction¶

This document describes all commands currently supported by QMP.

Most of the time their usage is exactly the same as in the user Monitor, this means that any other document which also describe commands (the manpage, QEMU’s manual, etc) can and should be consulted.

QMP has two types of commands: regular and query commands. Regular commands usually change the Virtual Machine’s state someway, while query commands just return information. The sections below are divided accordingly.

It’s important to observe that all communication examples are formatted in a reader-friendly way, so that they’re easier to understand. However, in real protocol usage, they’re emitted as a single line.

Also, the following notation is used to denote data flow:

Example:

-> data issued by the Client
<- Server data response

Please, refer to the QMP specification (docs/interop/qmp-spec.txt) for detailed information on the Server command and response formats.

Stability Considerations¶

The current QMP command set (described in this file) may be useful for a number of use cases, however it’s limited and several commands have bad defined semantics, specially with regard to command completion.

These problems are going to be solved incrementally in the next QEMU releases and we’re going to establish a deprecation policy for badly defined commands.

If you’re planning to adopt QMP, please observe the following:

The deprecation policy will take effect and be documented soon, please check the documentation of each used command as soon as a new release of QEMU is available

DO NOT rely on anything which is not explicit documented

Errors, in special, are not documented. Applications should NOT check for specific errors classes or data (it’s strongly recommended to only check for the “error” key)

QMP errors¶

`QapiErrorClass` (Enum)¶

QEMU error classes

Values¶

GenericError: this is used for errors that don’t require a specific error class. This should be the default case for most errors
CommandNotFound: the requested command has not been found
DeviceNotActive: a device has failed to be become active
DeviceNotFound: the requested device has not been found
KVMMissingCap: the requested operation can’t be fulfilled because a required KVM capability is missing

Since¶

1.2

Common data types¶

`IoOperationType` (Enum)¶

An enumeration of the I/O operation types

Values¶

read: read operation
write: write operation

Since¶

2.1

`OnOffAuto` (Enum)¶

An enumeration of three options: on, off, and auto

Values¶

auto: QEMU selects the value between on and off
on: Enabled
off: Disabled

Since¶

2.2

`OnOffSplit` (Enum)¶

An enumeration of three values: on, off, and split

Values¶

on: Enabled
off: Disabled
split: Mixed

Since¶

2.6

`String` (Object)¶

A fat type wrapping ‘str’, to be embedded in lists.

Members¶

str: string: Not documented

Since¶

1.2

`StrOrNull` (Alternate)¶

This is a string value or the explicit lack of a string (null pointer in C). Intended for cases when ‘optional absent’ already has a different meaning.

Members¶

s: string: the string value
n: null: no string value

Since¶

2.10

`OffAutoPCIBAR` (Enum)¶

An enumeration of options for specifying a PCI BAR

Values¶

off: The specified feature is disabled
auto: The PCI BAR for the feature is automatically selected
bar0: PCI BAR0 is used for the feature
bar1: PCI BAR1 is used for the feature
bar2: PCI BAR2 is used for the feature
bar3: PCI BAR3 is used for the feature
bar4: PCI BAR4 is used for the feature
bar5: PCI BAR5 is used for the feature

Since¶

2.12

`PCIELinkSpeed` (Enum)¶

An enumeration of PCIe link speeds in units of GT/s

Values¶

2_5: 2.5GT/s
5: 5.0GT/s
8: 8.0GT/s
16: 16.0GT/s

Since¶

4.0

`PCIELinkWidth` (Enum)¶

An enumeration of PCIe link width

Values¶

1: x1
2: x2
4: x4
8: x8
12: x12
16: x16
32: x32

Since¶

4.0

`HostMemPolicy` (Enum)¶

Host memory policy types

Values¶

default: restore default policy, remove any nondefault policy
preferred: set the preferred host nodes for allocation
bind: a strict policy that restricts memory allocation to the host nodes specified
interleave: memory allocations are interleaved across the set of host nodes specified

Since¶

2.1

`NetFilterDirection` (Enum)¶

Indicates whether a netfilter is attached to a netdev’s transmit queue or receive queue or both.

Values¶

all: the filter is attached both to the receive and the transmit queue of the netdev (default).
rx: the filter is attached to the receive queue of the netdev, where it will receive packets sent to the netdev.
tx: the filter is attached to the transmit queue of the netdev, where it will receive packets sent by the netdev.

Since¶

2.5

`GrabToggleKeys` (Enum)¶

Keys to toggle input-linux between host and guest.

Values¶

ctrl-ctrl: Not documented
alt-alt: Not documented
shift-shift: Not documented
meta-meta: Not documented
scrolllock: Not documented
ctrl-scrolllock: Not documented

Since¶

4.0

Socket data types¶

`NetworkAddressFamily` (Enum)¶

The network address family

Values¶

ipv4: IPV4 family
ipv6: IPV6 family
unix: unix socket
vsock: vsock family (since 2.8)
unknown: otherwise

Since¶

2.1

`InetSocketAddressBase` (Object)¶

Members¶

host: string: host part of the address
port: string: port part of the address

`InetSocketAddress` (Object)¶

Captures a socket address or address range in the Internet namespace.

Members¶

numeric: boolean (optional): true if the host/port are guaranteed to be numeric, false if name resolution should be attempted. Defaults to false. (Since 2.9)
to: int (optional): If present, this is range of possible addresses, with port between port and to.
ipv4: boolean (optional): whether to accept IPv4 addresses, default try both IPv4 and IPv6
ipv6: boolean (optional): whether to accept IPv6 addresses, default try both IPv4 and IPv6
keep-alive: boolean (optional): enable keep-alive when connecting to this socket. Not supported for passive sockets. (Since 4.2)
The members of InetSocketAddressBase

Since¶

1.3

`UnixSocketAddress` (Object)¶

Captures a socket address in the local (“Unix socket”) namespace.

Members¶

path: string: filesystem path to use
abstract: boolean (optional) (If: defined(CONFIG_LINUX)): if true, this is a Linux abstract socket address. path will be prefixed by a null byte, and optionally padded with null bytes. Defaults to false. (Since 5.1)
tight: boolean (optional) (If: defined(CONFIG_LINUX)): if false, pad an abstract socket address with enough null bytes to make it fill struct sockaddr_un member sun_path. Defaults to true. (Since 5.1)

Since¶

1.3

`VsockSocketAddress` (Object)¶

Captures a socket address in the vsock namespace.

Members¶

cid: string: unique host identifier
port: string: port

VM run state¶

`RunState` (Enum)¶

An enumeration of VM run states.

Values¶

debug: QEMU is running on a debugger
finish-migrate: guest is paused to finish the migration process
inmigrate: guest is paused waiting for an incoming migration. Note that this state does not tell whether the machine will start at the end of the migration. This depends on the command-line -S option and any invocation of ‘stop’ or ‘cont’ that has happened since QEMU was started.
internal-error: An internal error that prevents further guest execution has occurred
io-error: the last IOP has failed and the device is configured to pause on I/O errors
paused: guest has been paused via the ‘stop’ command
postmigrate: guest is paused following a successful ‘migrate’
prelaunch: QEMU was started with -S and guest has not started
restore-vm: guest is paused to restore VM state
running: guest is actively running
save-vm: guest is paused to save the VM state
shutdown: guest is shut down (and -no-shutdown is in use)
suspended: guest is suspended (ACPI S3)
watchdog: the watchdog action is configured to pause and has been triggered
guest-panicked: guest has been panicked as a result of guest OS panic
colo: guest is paused to save/restore VM state under colo checkpoint, VM can not get into this state unless colo capability is enabled for migration. (since 2.8)

`ShutdownCause` (Enum)¶

An enumeration of reasons for a Shutdown.

Values¶

none: No shutdown request pending
host-error: An error prevents further use of guest
host-qmp-quit: Reaction to the QMP command ‘quit’
host-qmp-system-reset: Reaction to the QMP command ‘system_reset’
host-signal: Reaction to a signal, such as SIGINT
host-ui: Reaction to a UI event, like window close
guest-shutdown: Guest shutdown/suspend request, via ACPI or other hardware-specific means
guest-reset: Guest reset request, and command line turns that into a shutdown
guest-panic: Guest panicked, and command line turns that into a shutdown
subsystem-reset: Partial guest reset that does not trigger QMP events and ignores –no-reboot. This is useful for sanitizing hypercalls on s390 that are used during kexec/kdump/boot

`StatusInfo` (Object)¶

Information about VCPU run state

Members¶

running: boolean: true if all VCPUs are runnable, false if not runnable
singlestep: boolean: true if VCPUs are in single-step mode
status: RunState: the virtual machine RunState

Since¶

0.14

Notes¶

singlestep is enabled through the GDB stub

`query-status` (Command)¶

Query the run status of all VCPUs

Returns¶

StatusInfo reflecting all VCPUs

Since¶

0.14

Example¶

-> { "execute": "query-status" }
<- { "return": { "running": true,
                 "singlestep": false,
                 "status": "running" } }

`SHUTDOWN` (Event)¶

Emitted when the virtual machine has shut down, indicating that qemu is about to exit.

Arguments¶

guest: boolean: If true, the shutdown was triggered by a guest request (such as a guest-initiated ACPI shutdown request or other hardware-specific action) rather than a host request (such as sending qemu a SIGINT). (since 2.10)
reason: ShutdownCause: The ShutdownCause which resulted in the SHUTDOWN. (since 4.0)

Note¶

If the command-line option “-no-shutdown” has been specified, qemu will not exit, and a STOP event will eventually follow the SHUTDOWN event

Since¶

0.12

Example¶

<- { "event": "SHUTDOWN", "data": { "guest": true },
     "timestamp": { "seconds": 1267040730, "microseconds": 682951 } }

`POWERDOWN` (Event)¶

Emitted when the virtual machine is powered down through the power control system, such as via ACPI.

Since¶

0.12

Example¶

<- { "event": "POWERDOWN",
     "timestamp": { "seconds": 1267040730, "microseconds": 682951 } }

`RESET` (Event)¶

Emitted when the virtual machine is reset

Arguments¶

guest: boolean: If true, the reset was triggered by a guest request (such as a guest-initiated ACPI reboot request or other hardware-specific action) rather than a host request (such as the QMP command system_reset). (since 2.10)
reason: ShutdownCause: The ShutdownCause of the RESET. (since 4.0)

Since¶

0.12

Example¶

<- { "event": "RESET", "data": { "guest": false },
     "timestamp": { "seconds": 1267041653, "microseconds": 9518 } }

`STOP` (Event)¶

Emitted when the virtual machine is stopped

Since¶

0.12

Example¶

<- { "event": "STOP",
     "timestamp": { "seconds": 1267041730, "microseconds": 281295 } }

`RESUME` (Event)¶

Emitted when the virtual machine resumes execution

Since¶

0.12

Example¶

<- { "event": "RESUME",
     "timestamp": { "seconds": 1271770767, "microseconds": 582542 } }

`SUSPEND` (Event)¶

Emitted when guest enters a hardware suspension state, for example, S3 state, which is sometimes called standby state

Since¶

1.1

Example¶

<- { "event": "SUSPEND",
     "timestamp": { "seconds": 1344456160, "microseconds": 309119 } }

`SUSPEND_DISK` (Event)¶

Emitted when guest enters a hardware suspension state with data saved on disk, for example, S4 state, which is sometimes called hibernate state

Note¶

QEMU shuts down (similar to event SHUTDOWN) when entering this state

Since¶

1.2

Example¶

<-   { "event": "SUSPEND_DISK",
       "timestamp": { "seconds": 1344456160, "microseconds": 309119 } }

`WAKEUP` (Event)¶

Emitted when the guest has woken up from suspend state and is running

Since¶

1.1

Example¶

<- { "event": "WAKEUP",
     "timestamp": { "seconds": 1344522075, "microseconds": 745528 } }

`WATCHDOG` (Event)¶

Emitted when the watchdog device’s timer is expired

Arguments¶

action: WatchdogAction: action that has been taken

Note¶

If action is “reset”, “shutdown”, or “pause” the WATCHDOG event is followed respectively by the RESET, SHUTDOWN, or STOP events

Note¶

This event is rate-limited.

Since¶

0.13

Example¶

<- { "event": "WATCHDOG",
     "data": { "action": "reset" },
     "timestamp": { "seconds": 1267061043, "microseconds": 959568 } }

`WatchdogAction` (Enum)¶

An enumeration of the actions taken when the watchdog device’s timer is expired

Values¶

reset: system resets
shutdown: system shutdown, note that it is similar to powerdown, which tries to set to system status and notify guest
poweroff: system poweroff, the emulator program exits
pause: system pauses, similar to stop
debug: system enters debug state
none: nothing is done
inject-nmi: a non-maskable interrupt is injected into the first VCPU (all VCPUS on x86) (since 2.4)

Since¶

2.1

`RebootAction` (Enum)¶

Possible QEMU actions upon guest reboot

Values¶

reset: Reset the VM
shutdown: Shutdown the VM and exit, according to the shutdown action

Since¶

6.0

`ShutdownAction` (Enum)¶

Possible QEMU actions upon guest shutdown

Values¶

poweroff: Shutdown the VM and exit
pause: pause the VM#

Since¶

6.0

`PanicAction` (Enum)¶

Values¶

none: Continue VM execution
pause: Pause the VM
shutdown: Shutdown the VM and exit, according to the shutdown action

Since¶

6.0

`watchdog-set-action` (Command)¶

Set watchdog action

Arguments¶

action: WatchdogAction: Not documented

Since¶

2.11

`set-action` (Command)¶

Set the actions that will be taken by the emulator in response to guest events.

Arguments¶

reboot: RebootAction (optional): RebootAction action taken on guest reboot.
shutdown: ShutdownAction (optional): ShutdownAction action taken on guest shutdown.
panic: PanicAction (optional): PanicAction action taken on guest panic.
watchdog: WatchdogAction (optional): WatchdogAction action taken when watchdog timer expires .

Returns¶

Nothing on success.

Since¶

6.0

Example¶

-> { "execute": "set-action",
     "arguments": { "reboot": "shutdown",
                    "shutdown" : "pause",
                    "panic": "pause",
                    "watchdog": "inject-nmi" } }
<- { "return": {} }

`GUEST_PANICKED` (Event)¶

Emitted when guest OS panic is detected

Arguments¶

action: GuestPanicAction: action that has been taken, currently always “pause”
info: GuestPanicInformation (optional): information about a panic (since 2.9)

Since¶

1.5

Example¶

<- { "event": "GUEST_PANICKED",
     "data": { "action": "pause" } }

`GUEST_CRASHLOADED` (Event)¶

Emitted when guest OS crash loaded is detected

Arguments¶

action: GuestPanicAction: action that has been taken, currently always “run”
info: GuestPanicInformation (optional): information about a panic

Since¶

5.0

Example¶

<- { "event": "GUEST_CRASHLOADED",
     "data": { "action": "run" } }

`GuestPanicAction` (Enum)¶

An enumeration of the actions taken when guest OS panic is detected

Values¶

pause: system pauses
poweroff: Not documented
run: Not documented

Since¶

2.1 (poweroff since 2.8, run since 5.0)

`GuestPanicInformationType` (Enum)¶

An enumeration of the guest panic information types

Values¶

hyper-v: hyper-v guest panic information type
s390: s390 guest panic information type (Since: 2.12)

Since¶

2.9

`GuestPanicInformation` (Object)¶

Information about a guest panic

Members¶

type: GuestPanicInformationType: Crash type that defines the hypervisor specific information
The members of GuestPanicInformationHyperV when type is "hyper-v"
The members of GuestPanicInformationS390 when type is "s390"

Since¶

2.9

`GuestPanicInformationHyperV` (Object)¶

Hyper-V specific guest panic information (HV crash MSRs)

Members¶

arg1: int: Not documented
arg2: int: Not documented
arg3: int: Not documented
arg4: int: Not documented
arg5: int: Not documented

Since¶

2.9

`S390CrashReason` (Enum)¶

Reason why the CPU is in a crashed state.

Values¶

unknown: no crash reason was set
disabled-wait: the CPU has entered a disabled wait state
extint-loop: clock comparator or cpu timer interrupt with new PSW enabled for external interrupts
pgmint-loop: program interrupt with BAD new PSW
opint-loop: operation exception interrupt with invalid code at the program interrupt new PSW

Since¶

2.12

`GuestPanicInformationS390` (Object)¶

S390 specific guest panic information (PSW)

Members¶

core: int: core id of the CPU that crashed
psw-mask: int: control fields of guest PSW
psw-addr: int: guest instruction address
reason: S390CrashReason: guest crash reason

Since¶

2.12

`MEMORY_FAILURE` (Event)¶

Emitted when a memory failure occurs on host side.

Arguments¶

recipient: MemoryFailureRecipient: recipient is defined as MemoryFailureRecipient.
action: MemoryFailureAction: action that has been taken. action is defined as MemoryFailureAction.
flags: MemoryFailureFlags: flags for MemoryFailureAction. action is defined as MemoryFailureFlags.

Since¶

5.2

Example¶

<- { "event": "MEMORY_FAILURE",
     "data": { "recipient": "hypervisor",
               "action": "fatal",
               "flags": { 'action-required': false } }

`MemoryFailureRecipient` (Enum)¶

Hardware memory failure occurs, handled by recipient.

Values¶

hypervisor: memory failure at QEMU process address space. (none guest memory, but used by QEMU itself).
guest: memory failure at guest memory,

Since¶

5.2

`MemoryFailureAction` (Enum)¶

Actions taken by QEMU in response to a hardware memory failure.

Values¶

ignore: the memory failure could be ignored. This will only be the case for action-optional failures.
inject: memory failure occurred in guest memory, the guest enabled MCE handling mechanism, and QEMU could inject the MCE into the guest successfully.
fatal: the failure is unrecoverable. This occurs for action-required failures if the recipient is the hypervisor; QEMU will exit.
reset: the failure is unrecoverable but confined to the guest. This occurs if the recipient is a guest guest which is not ready to handle memory failures.

Since¶

5.2

`MemoryFailureFlags` (Object)¶

Additional information on memory failures.

Members¶

action-required: boolean: whether a memory failure event is action-required or action-optional (e.g. a failure during memory scrub).
recursive: boolean: whether the failure occurred while the previous failure was still in progress.

Since¶

5.2

Cryptography¶

`QCryptoTLSCredsEndpoint` (Enum)¶

The type of network endpoint that will be using the credentials. Most types of credential require different setup / structures depending on whether they will be used in a server versus a client.

Values¶

client: the network endpoint is acting as the client
server: the network endpoint is acting as the server

Since¶

2.5

`QCryptoSecretFormat` (Enum)¶

The data format that the secret is provided in

Values¶

raw: raw bytes. When encoded in JSON only valid UTF-8 sequences can be used
base64: arbitrary base64 encoded binary data

Since¶

2.6

`QCryptoHashAlgorithm` (Enum)¶

The supported algorithms for computing content digests

Values¶

md5: MD5. Should not be used in any new code, legacy compat only
sha1: SHA-1. Should not be used in any new code, legacy compat only
sha224: SHA-224. (since 2.7)
sha256: SHA-256. Current recommended strong hash.
sha384: SHA-384. (since 2.7)
sha512: SHA-512. (since 2.7)
ripemd160: RIPEMD-160. (since 2.7)

Since¶

2.6

`QCryptoCipherAlgorithm` (Enum)¶

The supported algorithms for content encryption ciphers

Values¶

aes-128: AES with 128 bit / 16 byte keys
aes-192: AES with 192 bit / 24 byte keys
aes-256: AES with 256 bit / 32 byte keys
des-rfb: RFB specific variant of single DES. Do not use except in VNC.
3des: 3DES(EDE) with 192 bit / 24 byte keys (since 2.9)
cast5-128: Cast5 with 128 bit / 16 byte keys
serpent-128: Serpent with 128 bit / 16 byte keys
serpent-192: Serpent with 192 bit / 24 byte keys
serpent-256: Serpent with 256 bit / 32 byte keys
twofish-128: Twofish with 128 bit / 16 byte keys
twofish-192: Twofish with 192 bit / 24 byte keys
twofish-256: Twofish with 256 bit / 32 byte keys

Since¶

2.6

`QCryptoCipherMode` (Enum)¶

The supported modes for content encryption ciphers

Values¶

ecb: Electronic Code Book
cbc: Cipher Block Chaining
xts: XEX with tweaked code book and ciphertext stealing
ctr: Counter (Since 2.8)

Since¶

2.6

`QCryptoIVGenAlgorithm` (Enum)¶

The supported algorithms for generating initialization vectors for full disk encryption. The ‘plain’ generator should not be used for disks with sector numbers larger than 2^32, except where compatibility with pre-existing Linux dm-crypt volumes is required.

Values¶

plain: 64-bit sector number truncated to 32-bits
plain64: 64-bit sector number
essiv: 64-bit sector number encrypted with a hash of the encryption key

Since¶

2.6

`QCryptoBlockFormat` (Enum)¶

The supported full disk encryption formats

Values¶

qcow: QCow/QCow2 built-in AES-CBC encryption. Use only for liberating data from old images.
luks: LUKS encryption format. Recommended for new images

Since¶

2.6

`QCryptoBlockOptionsBase` (Object)¶

The common options that apply to all full disk encryption formats

Members¶

format: QCryptoBlockFormat: the encryption format

Since¶

2.6

`QCryptoBlockOptionsQCow` (Object)¶

The options that apply to QCow/QCow2 AES-CBC encryption format

Members¶

key-secret: string (optional): the ID of a QCryptoSecret object providing the decryption key. Mandatory except when probing image for metadata only.

Since¶

2.6

`QCryptoBlockOptionsLUKS` (Object)¶

The options that apply to LUKS encryption format

Members¶

key-secret: string (optional): the ID of a QCryptoSecret object providing the decryption key. Mandatory except when probing image for metadata only.

Since¶

2.6

`QCryptoBlockCreateOptionsLUKS` (Object)¶

The options that apply to LUKS encryption format initialization

Members¶

cipher-alg: QCryptoCipherAlgorithm (optional): the cipher algorithm for data encryption Currently defaults to ‘aes-256’.
cipher-mode: QCryptoCipherMode (optional): the cipher mode for data encryption Currently defaults to ‘xts’
ivgen-alg: QCryptoIVGenAlgorithm (optional): the initialization vector generator Currently defaults to ‘plain64’
ivgen-hash-alg: QCryptoHashAlgorithm (optional): the initialization vector generator hash Currently defaults to ‘sha256’
hash-alg: QCryptoHashAlgorithm (optional): the master key hash algorithm Currently defaults to ‘sha256’
iter-time: int (optional): number of milliseconds to spend in PBKDF passphrase processing. Currently defaults to 2000. (since 2.8)
The members of QCryptoBlockOptionsLUKS

Since¶

2.6

`QCryptoBlockOpenOptions` (Object)¶

The options that are available for all encryption formats when opening an existing volume

Members¶

The members of QCryptoBlockOptionsBase
The members of QCryptoBlockOptionsQCow when format is "qcow"
The members of QCryptoBlockOptionsLUKS when format is "luks"

Since¶

2.6

`QCryptoBlockCreateOptions` (Object)¶

The options that are available for all encryption formats when initializing a new volume

Members¶

The members of QCryptoBlockOptionsBase
The members of QCryptoBlockOptionsQCow when format is "qcow"
The members of QCryptoBlockCreateOptionsLUKS when format is "luks"

Since¶

2.6

`QCryptoBlockInfoBase` (Object)¶

The common information that applies to all full disk encryption formats

Members¶

format: QCryptoBlockFormat: the encryption format

Since¶

2.7

`QCryptoBlockInfoLUKSSlot` (Object)¶

Information about the LUKS block encryption key slot options

Members¶

active: boolean: whether the key slot is currently in use
key-offset: int: offset to the key material in bytes
iters: int (optional): number of PBKDF2 iterations for key material
stripes: int (optional): number of stripes for splitting key material

Since¶

2.7

`QCryptoBlockInfoLUKS` (Object)¶

Information about the LUKS block encryption options

Members¶

cipher-alg: QCryptoCipherAlgorithm: the cipher algorithm for data encryption
cipher-mode: QCryptoCipherMode: the cipher mode for data encryption
ivgen-alg: QCryptoIVGenAlgorithm: the initialization vector generator
ivgen-hash-alg: QCryptoHashAlgorithm (optional): the initialization vector generator hash
hash-alg: QCryptoHashAlgorithm: the master key hash algorithm
payload-offset: int: offset to the payload data in bytes
master-key-iters: int: number of PBKDF2 iterations for key material
uuid: string: unique identifier for the volume
slots: array of QCryptoBlockInfoLUKSSlot: information about each key slot

Since¶

2.7

`QCryptoBlockInfo` (Object)¶

Information about the block encryption options

Members¶

The members of QCryptoBlockInfoBase
The members of QCryptoBlockInfoLUKS when format is "luks"

Since¶

2.7

`QCryptoBlockLUKSKeyslotState` (Enum)¶

Defines state of keyslots that are affected by the update

Values¶

active: The slots contain the given password and marked as active
inactive: The slots are erased (contain garbage) and marked as inactive

Since¶

5.1

`QCryptoBlockAmendOptionsLUKS` (Object)¶

This struct defines the update parameters that activate/de-activate set of keyslots

Members¶

state: QCryptoBlockLUKSKeyslotState

the desired state of the keyslots

new-secret: string (optional)

The ID of a QCryptoSecret object providing the password to be written into added active keyslots

old-secret: string (optional)

Optional (for deactivation only) If given will deactivate all keyslots that match password located in QCryptoSecret with this ID

iter-time: int (optional)

Optional (for activation only) Number of milliseconds to spend in PBKDF passphrase processing for the newly activated keyslot. Currently defaults to 2000.

keyslot: int (optional)

Optional. ID of the keyslot to activate/deactivate. For keyslot activation, keyslot should not be active already (this is unsafe to update an active keyslot), but possible if ‘force’ parameter is given. If keyslot is not given, first free keyslot will be written.

For keyslot deactivation, this parameter specifies the exact keyslot to deactivate

secret: string (optional)

Optional. The ID of a QCryptoSecret object providing the password to use to retrieve current master key. Defaults to the same secret that was used to open the image

Since 5.1

`QCryptoBlockAmendOptions` (Object)¶

The options that are available for all encryption formats when amending encryption settings

Members¶

The members of QCryptoBlockOptionsBase
The members of QCryptoBlockAmendOptionsLUKS when format is "luks"

Since¶

5.1

`SecretCommonProperties` (Object)¶

Properties for objects of classes derived from secret-common.

Members¶

loaded: boolean (optional): if true, the secret is loaded immediately when applying this option and will probably fail when processing the next option. Don’t use; only provided for compatibility. (default: false)
format: QCryptoSecretFormat (optional): the data format that the secret is provided in (default: raw)
keyid: string (optional): the name of another secret that should be used to decrypt the provided data. If not present, the data is assumed to be unencrypted.
iv: string (optional): the random initialization vector used for encryption of this particular secret. Should be a base64 encrypted string of the 16-byte IV. Mandatory if keyid is given. Ignored if keyid is absent.

Features¶

deprecated: Member loaded is deprecated. Setting true doesn’t make sense, and false is already the default.

Since¶

2.6

`SecretProperties` (Object)¶

Properties for secret objects.

Either data or file must be provided, but not both.

Members¶

data: string (optional): the associated with the secret from
file: string (optional): the filename to load the data associated with the secret from
The members of SecretCommonProperties

Since¶

2.6

`SecretKeyringProperties` (Object)¶

Properties for secret_keyring objects.

Members¶

serial: int: serial number that identifies a key to get from the kernel
The members of SecretCommonProperties

Since¶

5.1

`TlsCredsProperties` (Object)¶

Properties for objects of classes derived from tls-creds.

Members¶

verify-peer: boolean (optional): if true the peer credentials will be verified once the handshake is completed. This is a no-op for anonymous credentials. (default: true)
dir: string (optional): the path of the directory that contains the credential files
endpoint: QCryptoTLSCredsEndpoint (optional): whether the QEMU network backend that uses the credentials will be acting as a client or as a server (default: client)
priority: string (optional): a gnutls priority string as described at https://gnutls.org/manual/html_node/Priority-Strings.html

Since¶

2.5

`TlsCredsAnonProperties` (Object)¶

Properties for tls-creds-anon objects.

Members¶

loaded: boolean (optional): if true, the credentials are loaded immediately when applying this option and will ignore options that are processed later. Don’t use; only provided for compatibility. (default: false)
The members of TlsCredsProperties

Features¶

deprecated: Member loaded is deprecated. Setting true doesn’t make sense, and false is already the default.

Since¶

2.5

`TlsCredsPskProperties` (Object)¶

Properties for tls-creds-psk objects.

Members¶

loaded: boolean (optional): if true, the credentials are loaded immediately when applying this option and will ignore options that are processed later. Don’t use; only provided for compatibility. (default: false)
username: string (optional): the username which will be sent to the server. For clients only. If absent, “qemu” is sent and the property will read back as an empty string.
The members of TlsCredsProperties

Features¶

deprecated: Member loaded is deprecated. Setting true doesn’t make sense, and false is already the default.

Since¶

3.0

`TlsCredsX509Properties` (Object)¶

Properties for tls-creds-x509 objects.

Members¶

loaded: boolean (optional): if true, the credentials are loaded immediately when applying this option and will ignore options that are processed later. Don’t use; only provided for compatibility. (default: false)
sanity-check: boolean (optional): if true, perform some sanity checks before using the credentials (default: true)
passwordid: string (optional): For the server-key.pem and client-key.pem files which contain sensitive private keys, it is possible to use an encrypted version by providing the passwordid parameter. This provides the ID of a previously created secret object containing the password for decryption.
The members of TlsCredsProperties

Features¶

deprecated: Member loaded is deprecated. Setting true doesn’t make sense, and false is already the default.

Since¶

2.5

Block devices¶

Block core (VM unrelated)¶

Background jobs¶

`JobType` (Enum)¶

Type of a background job.

Values¶

commit: block commit job type, see “block-commit”
stream: block stream job type, see “block-stream”
mirror: drive mirror job type, see “drive-mirror”
backup: drive backup job type, see “drive-backup”
create: image creation job type, see “blockdev-create” (since 3.0)
amend: image options amend job type, see “x-blockdev-amend” (since 5.1)
snapshot-load: snapshot load job type, see “snapshot-load” (since 6.0)
snapshot-save: snapshot save job type, see “snapshot-save” (since 6.0)
snapshot-delete: snapshot delete job type, see “snapshot-delete” (since 6.0)

Since¶

1.7

`JobStatus` (Enum)¶

Indicates the present state of a given job in its lifetime.

Values¶

undefined: Erroneous, default state. Should not ever be visible.
created: The job has been created, but not yet started.
running: The job is currently running.
paused: The job is running, but paused. The pause may be requested by either the QMP user or by internal processes.
ready: The job is running, but is ready for the user to signal completion. This is used for long-running jobs like mirror that are designed to run indefinitely.
standby: The job is ready, but paused. This is nearly identical to paused. The job may return to ready or otherwise be canceled.
waiting: The job is waiting for other jobs in the transaction to converge to the waiting state. This status will likely not be visible for the last job in a transaction.
pending: The job has finished its work, but has finalization steps that it needs to make prior to completing. These changes will require manual intervention via job-finalize if auto-finalize was set to false. These pending changes may still fail.
aborting: The job is in the process of being aborted, and will finish with an error. The job will afterwards report that it is concluded. This status may not be visible to the management process.
concluded: The job has finished all work. If auto-dismiss was set to false, the job will remain in the query list until it is dismissed via job-dismiss.
null: The job is in the process of being dismantled. This state should not ever be visible externally.

Since¶

2.12

`JobVerb` (Enum)¶

Represents command verbs that can be applied to a job.

Values¶

cancel: see job-cancel
pause: see job-pause
resume: see job-resume
set-speed: see block-job-set-speed
complete: see job-complete
dismiss: see job-dismiss
finalize: see job-finalize

Since¶

2.12

`JOB_STATUS_CHANGE` (Event)¶

Emitted when a job transitions to a different status.

Arguments¶

id: string: The job identifier
status: JobStatus: The new job status

Since¶

3.0

`job-pause` (Command)¶

Pause an active job.

This command returns immediately after marking the active job for pausing. Pausing an already paused job is an error.

The job will pause as soon as possible, which means transitioning into the PAUSED state if it was RUNNING, or into STANDBY if it was READY. The corresponding JOB_STATUS_CHANGE event will be emitted.

Cancelling a paused job automatically resumes it.

Arguments¶

id: string: The job identifier.

Since¶

3.0

`job-resume` (Command)¶

Resume a paused job.

This command returns immediately after resuming a paused job. Resuming an already running job is an error.

id : The job identifier.

Arguments¶

id: string: Not documented

Since¶

3.0

`job-cancel` (Command)¶

Instruct an active background job to cancel at the next opportunity. This command returns immediately after marking the active job for cancellation.

The job will cancel as soon as possible and then emit a JOB_STATUS_CHANGE event. Usually, the status will change to ABORTING, but it is possible that a job successfully completes (e.g. because it was almost done and there was no opportunity to cancel earlier than completing the job) and transitions to PENDING instead.

Arguments¶

id: string: The job identifier.

Since¶

3.0

`job-complete` (Command)¶

Manually trigger completion of an active job in the READY state.

Arguments¶

id: string: The job identifier.

Since¶

3.0

`job-dismiss` (Command)¶

Deletes a job that is in the CONCLUDED state. This command only needs to be run explicitly for jobs that don’t have automatic dismiss enabled.

This command will refuse to operate on any job that has not yet reached its terminal state, JOB_STATUS_CONCLUDED. For jobs that make use of JOB_READY event, job-cancel or job-complete will still need to be used as appropriate.

Arguments¶

id: string: The job identifier.

Since¶

3.0

`job-finalize` (Command)¶

Instructs all jobs in a transaction (or a single job if it is not part of any transaction) to finalize any graph changes and do any necessary cleanup. This command requires that all involved jobs are in the PENDING state.

For jobs in a transaction, instructing one job to finalize will force ALL jobs in the transaction to finalize, so it is only necessary to instruct a single member job to finalize.

Arguments¶

id: string: The identifier of any job in the transaction, or of a job that is not part of any transaction.

Since¶

3.0

`JobInfo` (Object)¶

Information about a job.

Members¶

id: string

The job identifier

type: JobType

The kind of job that is being performed

status: JobStatus

Current job state/status

current-progress: int

Progress made until now. The unit is arbitrary and the value can only meaningfully be used for the ratio of current-progress to total-progress. The value is monotonically increasing.

total-progress: int

Estimated current-progress value at the completion of the job. This value can arbitrarily change while the job is running, in both directions.

error: string (optional)

If this field is present, the job failed; if it is still missing in the CONCLUDED state, this indicates successful completion.

The value is a human-readable error message to describe the reason for the job failure. It should not be parsed by applications.

Since¶

3.0

`query-jobs` (Command)¶

Return information about jobs.

A discriminated record of image format specific information structures.

Members¶

type: One of qcow2, vmdk, luks
data: ImageInfoSpecificQCow2 when type is "qcow2"
data: ImageInfoSpecificVmdk when type is "vmdk"
data: QCryptoBlockInfoLUKS when type is "luks"

Since¶

1.7

`ImageInfo` (Object)¶

Information about a QEMU image file

Members¶

filename: string: name of the image file
format: string: format of the image file
virtual-size: int: maximum capacity in bytes of the image
actual-size: int (optional): actual size on disk in bytes of the image
dirty-flag: boolean (optional): true if image is not cleanly closed
cluster-size: int (optional): size of a cluster in bytes
encrypted: boolean (optional): true if the image is encrypted
compressed: boolean (optional): true if the image is compressed (Since 1.7)
backing-filename: string (optional): name of the backing file
full-backing-filename: string (optional): full path of the backing file
backing-filename-format: string (optional): the format of the backing file
snapshots: array of SnapshotInfo (optional): list of VM snapshots
backing-image: ImageInfo (optional): info of the backing image (since 1.6)
format-specific: ImageInfoSpecific (optional): structure supplying additional format-specific information (since 1.7)

Since¶

1.3

`ImageCheck` (Object)¶

Information about a QEMU image file check

Members¶

filename: string: name of the image file checked
format: string: format of the image file checked
check-errors: int: number of unexpected errors occurred during check
image-end-offset: int (optional): offset (in bytes) where the image ends, this field is present if the driver for the image format supports it
corruptions: int (optional): number of corruptions found during the check if any
leaks: int (optional): number of leaks found during the check if any
corruptions-fixed: int (optional): number of corruptions fixed during the check if any
leaks-fixed: int (optional): number of leaks fixed during the check if any
total-clusters: int (optional): total number of clusters, this field is present if the driver for the image format supports it
allocated-clusters: int (optional): total number of allocated clusters, this field is present if the driver for the image format supports it
fragmented-clusters: int (optional): total number of fragmented clusters, this field is present if the driver for the image format supports it
compressed-clusters: int (optional): total number of compressed clusters, this field is present if the driver for the image format supports it

Since¶

1.4

`MapEntry` (Object)¶

Mapping information from a virtual block range to a host file range

Members¶

start: int: virtual (guest) offset of the first byte described by this entry
length: int: the number of bytes of the mapped virtual range
data: boolean: reading the image will actually read data from a file (in particular, if offset is present this means that the sectors are not simply preallocated, but contain actual data in raw format)
zero: boolean: whether the virtual blocks read as zeroes
depth: int: number of layers (0 = top image, 1 = top image’s backing file, …, n - 1 = bottom image (where n is the number of images in the chain)) before reaching one for which the range is allocated
offset: int (optional): if present, the image file stores the data for this range in raw format at the given (host) offset
filename: string (optional): filename that is referred to by offset

Since¶

2.6

`BlockdevCacheInfo` (Object)¶

Cache mode information for a block device

Members¶

writeback: boolean: true if writeback mode is enabled
direct: boolean: true if the host page cache is bypassed (O_DIRECT)
no-flush: boolean: true if flush requests are ignored for the device

Since¶

2.3

`BlockDeviceInfo` (Object)¶

Information about the backing device for a block device.

Members¶

file: string

the filename of the backing device

node-name: string (optional)

the name of the block driver node (Since 2.0)

ro: boolean

true if the backing device was open read-only

drv: string

the name of the block format used to open the backing device. As of 0.14 this can be: ‘blkdebug’, ‘bochs’, ‘cloop’, ‘cow’, ‘dmg’, ‘file’, ‘file’, ‘ftp’, ‘ftps’, ‘host_cdrom’, ‘host_device’, ‘http’, ‘https’, ‘luks’, ‘nbd’, ‘parallels’, ‘qcow’, ‘qcow2’, ‘raw’, ‘vdi’, ‘vmdk’, ‘vpc’, ‘vvfat’ 2.2: ‘archipelago’ added, ‘cow’ dropped 2.3: ‘host_floppy’ deprecated 2.5: ‘host_floppy’ dropped 2.6: ‘luks’ added 2.8: ‘replication’ added, ‘tftp’ dropped 2.9: ‘archipelago’ dropped

backing_file: string (optional)

the name of the backing file (for copy-on-write)

backing_file_depth: int

number of files in the backing file chain (since: 1.2)

encrypted: boolean

true if the backing device is encrypted

detect_zeroes: BlockdevDetectZeroesOptions

detect and optimize zero writes (Since 2.1)

bps: int

total throughput limit in bytes per second is specified

bps_rd: int

read throughput limit in bytes per second is specified

bps_wr: int

write throughput limit in bytes per second is specified

iops: int

total I/O operations per second is specified

iops_rd: int

read I/O operations per second is specified

iops_wr: int

write I/O operations per second is specified

image: ImageInfo

the info of image used (since: 1.6)

bps_max: int (optional)

total throughput limit during bursts,: in bytes (Since 1.7)

bps_rd_max: int (optional)

read throughput limit during bursts,: in bytes (Since 1.7)

bps_wr_max: int (optional)

write throughput limit during bursts,: in bytes (Since 1.7)

iops_max: int (optional)

total I/O operations per second during bursts,: in bytes (Since 1.7)

iops_rd_max: int (optional)

read I/O operations per second during bursts,: in bytes (Since 1.7)

iops_wr_max: int (optional)

write I/O operations per second during bursts,: in bytes (Since 1.7)

bps_max_length: int (optional)

maximum length of the bps_max burst: period, in seconds. (Since 2.6)

bps_rd_max_length: int (optional)

maximum length of the bps_rd_max: burst period, in seconds. (Since 2.6)

bps_wr_max_length: int (optional)

maximum length of the bps_wr_max: burst period, in seconds. (Since 2.6)

iops_max_length: int (optional)

maximum length of the iops burst: period, in seconds. (Since 2.6)

iops_rd_max_length: int (optional)

maximum length of the iops_rd_max: burst period, in seconds. (Since 2.6)

iops_wr_max_length: int (optional)

maximum length of the iops_wr_max: burst period, in seconds. (Since 2.6)

iops_size: int (optional)

an I/O size in bytes (Since 1.7)

group: string (optional)

throttle group name (Since 2.4)

cache: BlockdevCacheInfo

the cache mode used for the block device (since: 2.3)

write_threshold: int

configured write threshold for the device. 0 if disabled. (Since 2.3)

dirty-bitmaps: array of BlockDirtyInfo (optional)

boundaries: array of int: list of interval boundary values in nanoseconds, all greater than zero and in ascending order. For example, the list [10, 50, 100] produces the following histogram intervals: [0, 10), [10, 50), [50, 100), [100, +inf).
bins: array of int: list of io request counts corresponding to histogram intervals. len(bins) = len(boundaries) + 1 For the example above, bins may be something like [3, 1, 5, 2], and corresponding histogram looks like:

          *
          *
*         *
*         *    *
*    *    *    *
 +------------------
 50   100

Since¶

4.0

`BlockInfo` (Object)¶

Block device information. This structure describes a virtual device and the backing device associated with it.

Members¶

device: string: The device name associated with the virtual device.
qdev: string (optional): The qdev ID, or if no ID is assigned, the QOM path of the block device. (since 2.10)
type: string: This field is returned only for compatibility reasons, it should not be used (always returns ‘unknown’)
removable: boolean: True if the device supports removable media.
locked: boolean: True if the guest has locked this device from having its media removed
tray_open: boolean (optional): True if the device’s tray is open (only present if it has a tray)
io-status: BlockDeviceIoStatus (optional): BlockDeviceIoStatus. Only present if the device supports it and the VM is configured to stop on errors (supported device models: virtio-blk, IDE, SCSI except scsi-generic)
inserted: BlockDeviceInfo (optional): BlockDeviceInfo describing the device if media is present

Since¶

0.14

`BlockMeasureInfo` (Object)¶

Image file size calculation information. This structure describes the size requirements for creating a new image file.

The size requirements depend on the new image file format. File size always equals virtual disk size for the ‘raw’ format, even for sparse POSIX files. Compact formats such as ‘qcow2’ represent unallocated and zero regions efficiently so file size may be smaller than virtual disk size.

The values are upper bounds that are guaranteed to fit the new image file. Subsequent modification, such as internal snapshot or further bitmap creation, may require additional space and is not covered here.

Members¶

required: int: Size required for a new image file, in bytes, when copying just allocated guest-visible contents.
fully-allocated: int: Image file size, in bytes, once data has been written to all sectors, when copying just guest-visible contents.
bitmaps: int (optional): Additional size required if all the top-level bitmap metadata in the source image were to be copied to the destination, present only when source and destination both support persistent bitmaps. (since 5.1)

Members¶

rd_bytes: int

The number of bytes read by the device.

wr_bytes: int

The number of bytes written by the device.

unmap_bytes: int

The number of bytes unmapped by the device (Since 4.2)

rd_operations: int

The number of read operations performed by the device.

wr_operations: int

The number of write operations performed by the device.

flush_operations: int

The number of cache flush operations performed by the device (since 0.15)

unmap_operations: int

The number of unmap operations performed by the device (Since 4.2)

rd_total_time_ns: int

Total time spent on reads in nanoseconds (since 0.15).

wr_total_time_ns: int

Total time spent on writes in nanoseconds (since 0.15).

flush_total_time_ns: int

Total time spent on cache flushes in nanoseconds (since 0.15).

unmap_total_time_ns: int

Total time spent on unmap operations in nanoseconds (Since 4.2)

wr_highest_offset: int

The offset after the greatest byte written to the device. The intended use of this information is for growable sparse files (like qcow2) that are used on top of a physical device.

rd_merged: int

Number of read requests that have been merged into another request (Since 2.3).

wr_merged: int

Number of write requests that have been merged into another request (Since 2.3).

unmap_merged: int

Number of unmap requests that have been merged into another request (Since 4.2)

idle_time_ns: int (optional)

Time since the last I/O operation, in nanoseconds. If the field is absent it means that there haven’t been any operations yet (Since 2.5).

failed_rd_operations: int

The number of failed read operations performed by the device (Since 2.5)

failed_wr_operations: int

The number of failed write operations performed by the device (Since 2.5)

failed_flush_operations: int

The number of failed flush operations performed by the device (Since 2.5)

failed_unmap_operations: int

The number of failed unmap operations performed by the device (Since 4.2)

invalid_rd_operations: int

The number of invalid read operations: performed by the device (Since 2.5)

invalid_wr_operations: int

The number of invalid write operations performed by the device (Since 2.5)

invalid_flush_operations: int

The number of invalid flush operations performed by the device (Since 2.5)

invalid_unmap_operations: int

The number of invalid unmap operations performed by the device (Since 4.2)

account_invalid: boolean

Whether invalid operations are included in the last access statistics (Since 2.5)

account_failed: boolean

Whether failed operations are included in the latency and last access statistics (Since 2.5)

timed_stats: array of BlockDeviceTimedStats

Statistics specific to the set of previously defined intervals of time (Since 2.5)

rd_latency_histogram: BlockLatencyHistogramInfo (optional)

BlockLatencyHistogramInfo. (Since 4.0)

wr_latency_histogram: BlockLatencyHistogramInfo (optional)

BlockLatencyHistogramInfo. (Since 4.0)

flush_latency_histogram: BlockLatencyHistogramInfo (optional)

-> { "execute": "query-blockstats" }
<- {
      "return":[
         {
            "device":"ide0-hd0",
            "parent":{
               "stats":{
                  "wr_highest_offset":3686448128,
                  "wr_bytes":9786368,
                  "wr_operations":751,
                  "rd_bytes":122567168,
                  "rd_operations":36772
                  "wr_total_times_ns":313253456
                  "rd_total_times_ns":3465673657
                  "flush_total_times_ns":49653
                  "flush_operations":61,
                  "rd_merged":0,
                  "wr_merged":0,
                  "idle_time_ns":2953431879,
                  "account_invalid":true,
                  "account_failed":false
               }
            },
            "stats":{
               "wr_highest_offset":2821110784,
               "wr_bytes":9786368,
               "wr_operations":692,
               "rd_bytes":122739200,
               "rd_operations":36604
               "flush_operations":51,
               "wr_total_times_ns":313253456
               "rd_total_times_ns":3465673657
               "flush_total_times_ns":49653,
               "rd_merged":0,
               "wr_merged":0,
               "idle_time_ns":2953431879,
               "account_invalid":true,
               "account_failed":false
            },
            "qdev": "/machine/unattached/device[23]"
         },
         {
            "device":"ide1-cd0",
            "stats":{
               "wr_highest_offset":0,
               "wr_bytes":0,
               "wr_operations":0,
               "rd_bytes":0,
               "rd_operations":0
               "flush_operations":0,
               "wr_total_times_ns":0
               "rd_total_times_ns":0
               "flush_total_times_ns":0,
               "rd_merged":0,
               "wr_merged":0,
               "account_invalid":false,
               "account_failed":false
            },
            "qdev": "/machine/unattached/device[24]"
         },
         {
            "device":"floppy0",
            "stats":{
               "wr_highest_offset":0,
               "wr_bytes":0,
               "wr_operations":0,
               "rd_bytes":0,
               "rd_operations":0
               "flush_operations":0,
               "wr_total_times_ns":0
               "rd_total_times_ns":0
               "flush_total_times_ns":0,
               "rd_merged":0,
               "wr_merged":0,
               "account_invalid":false,
               "account_failed":false
            },
            "qdev": "/machine/unattached/device[16]"
         },
         {
            "device":"sd0",
            "stats":{
               "wr_highest_offset":0,
               "wr_bytes":0,
               "wr_operations":0,
               "rd_bytes":0,
               "rd_operations":0
               "flush_operations":0,
               "wr_total_times_ns":0
               "rd_total_times_ns":0
               "flush_total_times_ns":0,
               "rd_merged":0,
               "wr_merged":0,
               "account_invalid":false,
               "account_failed":false
            }
         }
      ]
   }

`BlockdevOnError` (Enum)¶

An enumeration of possible behaviors for errors on I/O operations. The exact meaning depends on whether the I/O was initiated by a guest or by a block job

Values¶

report: for guest operations, report the error to the guest; for jobs, cancel the job
ignore: ignore the error, only report a QMP event (BLOCK_IO_ERROR or BLOCK_JOB_ERROR). The backup, mirror and commit block jobs retry the failing request later and may still complete successfully. The stream block job continues to stream and will complete with an error.
enospc: same as stop on ENOSPC, same as report otherwise.
stop: for guest operations, stop the virtual machine; for jobs, pause the job
auto: inherit the error handling policy of the backend (since: 2.7)

Since¶

1.3

`MirrorSyncMode` (Enum)¶

An enumeration of possible behaviors for the initial synchronization phase of storage mirroring.

Values¶

top: copies data in the topmost image to the destination
full: copies data from all images to the destination
none: only copy data written from now on
incremental: only copy data described by the dirty bitmap. (since: 2.4)
bitmap: only copy data described by the dirty bitmap. (since: 4.2) Behavior on completion is determined by the BitmapSyncMode.

Since¶

1.3

`BitmapSyncMode` (Enum)¶

An enumeration of possible behaviors for the synchronization of a bitmap when used for data copy operations.

Values¶

on-success: The bitmap is only synced when the operation is successful. This is the behavior always used for ‘INCREMENTAL’ backups.
never: The bitmap is never synchronized with the operation, and is treated solely as a read-only manifest of blocks to copy.
always: The bitmap is always synchronized with the operation, regardless of whether or not the operation was successful.

Since¶

4.2

`MirrorCopyMode` (Enum)¶

An enumeration whose values tell the mirror block job when to trigger writes to the target.

Values¶

background: copy data in background only.
write-blocking: when data is written to the source, write it (synchronously) to the target as well. In addition, data is copied in background just like in background mode.

Since¶

3.0

`BlockJobInfo` (Object)¶

Information about a long-running block device operation.

Members¶

type: string: the job type (‘stream’ for image streaming)
device: string: The job identifier. Originally the device name but other values are allowed since QEMU 2.7
len: int: Estimated offset value at the completion of the job. This value can arbitrarily change while the job is running, in both directions.
offset: int: Progress made until now. The unit is arbitrary and the value can only meaningfully be used for the ratio of offset to len. The value is monotonically increasing.
busy: boolean: false if the job is known to be in a quiescent state, with no pending I/O. Since 1.3.
paused: boolean: whether the job is paused or, if busy is true, will pause itself as soon as possible. Since 1.3.
speed: int: the rate limit, bytes per second
io-status: BlockDeviceIoStatus: the status of the job (since 1.3)
ready: boolean: true if the job may be completed (since 2.2)
status: JobStatus: Current job state/status (since 2.12)
auto-finalize: boolean: Job will finalize itself when PENDING, moving to the CONCLUDED state. (since 2.12)
auto-dismiss: boolean: Job will dismiss itself when CONCLUDED, moving to the NULL state and disappearing from the query list. (since 2.12)
error: string (optional): Error information if the job did not complete successfully. Not set if the job completed successfully. (since 2.12.1)

Since¶

1.1

`query-block-jobs` (Command)¶

Return information about long-running block device operations.

Returns¶

a list of BlockJobInfo for each active block job

Since¶

1.1

`block_resize` (Command)¶

Resize a block image while a guest is running.

Either device or node-name must be set but not both.

Arguments¶

device: string (optional): the name of the device to get the image resized
node-name: string (optional): graph node name to get the image resized (Since 2.0)
size: int: new image size in bytes

Returns¶

nothing on success
If device is not a valid block device, DeviceNotFound

Since¶

0.14

Example¶

-> { "execute": "block_resize",
     "arguments": { "device": "scratch", "size": 1073741824 } }
<- { "return": {} }

`NewImageMode` (Enum)¶

An enumeration that tells QEMU how to set the backing file path in a new image file.

Values¶

existing: QEMU should look for an existing image file.
absolute-paths: QEMU should create a new image with absolute paths for the backing file. If there is no backing file available, the new image will not be backed either.

Since¶

1.1

`BlockdevSnapshotSync` (Object)¶

Either device or node-name must be set but not both.

Members¶

device: string (optional): the name of the device to take a snapshot of.
node-name: string (optional): graph node name to generate the snapshot from (Since 2.0)
snapshot-file: string: the target of the new overlay image. If the file exists, or if it is a device, the overlay will be created in the existing file/device. Otherwise, a new file will be created.
snapshot-node-name: string (optional): the graph node name of the new image (Since 2.0)
format: string (optional): the format of the overlay image, default is ‘qcow2’.
mode: NewImageMode (optional): whether and how QEMU should create a new image, default is ‘absolute-paths’.

`BlockdevSnapshot` (Object)¶

Members¶

node: string: device or node name that will have a snapshot taken.
overlay: string: reference to the existing block device that will become the overlay of node, as part of taking the snapshot. It must not have a current backing file (this can be achieved by passing “backing”: null to blockdev-add).

Since¶

2.5

`BackupPerf` (Object)¶

Optional parameters for backup. These parameters don’t affect functionality, but may significantly affect performance.

Members¶

use-copy-range: boolean (optional): Use copy offloading. Default false.
max-workers: int (optional): Maximum number of parallel requests for the sustained background copying process. Doesn’t influence copy-before-write operations. Default 64.
max-chunk: int (optional): Maximum request length for the sustained background copying process. Doesn’t influence copy-before-write operations. 0 means unlimited. If max-chunk is non-zero then it should not be less than job cluster size which is calculated as maximum of target image cluster size and 64k. Default 0.

Since¶

6.0

`BackupCommon` (Object)¶

Members¶

job-id: string (optional): identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)
device: string: the device name or node-name of a root node which should be copied.
sync: MirrorSyncMode: what parts of the disk image should be copied to the destination (all the disk, only the sectors allocated in the topmost image, from a dirty bitmap, or only new I/O).
speed: int (optional): the maximum speed, in bytes per second. The default is 0, for unlimited.
bitmap: string (optional): The name of a dirty bitmap to use. Must be present if sync is “bitmap” or “incremental”. Can be present if sync is “full” or “top”. Must not be present otherwise. (Since 2.4 (drive-backup), 3.1 (blockdev-backup))
bitmap-mode: BitmapSyncMode (optional): Specifies the type of data the bitmap should contain after the operation concludes. Must be present if a bitmap was provided, Must NOT be present otherwise. (Since 4.2)
compress: boolean (optional): true to compress data, if the target format supports it. (default: false) (since 2.8)
on-source-error: BlockdevOnError (optional): the action to take on an error on the source, default ‘report’. ‘stop’ and ‘enospc’ can only be used if the block device supports io-status (see BlockInfo).
on-target-error: BlockdevOnError (optional): the action to take on an error on the target, default ‘report’ (no limitations, since this applies to a different block device than device).
auto-finalize: boolean (optional): When false, this job will wait in a PENDING state after it has finished its work, waiting for block-job-finalize before making any block graph changes. When true, this job will automatically perform its abort or commit actions. Defaults to true. (Since 2.12)
auto-dismiss: boolean (optional): When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and awaits block-job-dismiss. When true, this job will automatically disappear from the query list without user intervention. Defaults to true. (Since 2.12)
filter-node-name: string (optional): the node name that should be assigned to the filter driver that the backup job inserts into the graph above node specified by drive. If this option is not given, a node name is autogenerated. (Since: 4.2)
x-perf: BackupPerf (optional): Performance options. (Since 6.0)

Takes a synchronous snapshot of a block device.

For the arguments, see the documentation of BlockdevSnapshotSync.

Returns¶

nothing on success
If device is not a valid block device, DeviceNotFound

Since¶

0.14

Example¶

-> { "execute": "blockdev-snapshot-sync",
     "arguments": { "device": "ide-hd0",
                    "snapshot-file":
                    "/some/place/my-image",
                    "format": "qcow2" } }
<- { "return": {} }

`blockdev-snapshot` (Command)¶

Takes a snapshot of a block device.

Take a snapshot, by installing ‘node’ as the backing image of ‘overlay’. Additionally, if ‘node’ is associated with a block device, the block device changes to using ‘overlay’ as its new active image.

For the arguments, see the documentation of BlockdevSnapshot.

Features¶

allow-write-only-overlay: If present, the check whether this operation is safe was relaxed so that it can be used to change backing file of a destination of a blockdev-mirror. (since 5.0)

Since¶

2.5

Example¶

-> { "execute": "blockdev-add",
     "arguments": { "driver": "qcow2",
                    "node-name": "node1534",
                    "file": { "driver": "file",
                              "filename": "hd1.qcow2" },
                    "backing": null } }

<- { "return": {} }

-> { "execute": "blockdev-snapshot",
     "arguments": { "node": "ide-hd0",
                    "overlay": "node1534" } }
<- { "return": {} }

`change-backing-file` (Command)¶

Change the backing file in the image file metadata. This does not cause QEMU to reopen the image file to reparse the backing filename (it may, however, perform a reopen to change permissions from r/o -> r/w -> r/o, if needed). The new backing file string is written into the image file metadata, and the QEMU internal strings are updated.

Arguments¶

image-node-name: string: The name of the block driver state node of the image to modify. The “device” argument is used to verify “image-node-name” is in the chain described by “device”.
device: string: The device name or node-name of the root node that owns image-node-name.
backing-file: string: The string to write as the backing file. This string is not validated, so care should be taken when specifying the string or the image chain may not be able to be reopened again.

Returns¶

Nothing on success
If “device” does not exist or cannot be determined, DeviceNotFound

Since¶

2.1

`block-commit` (Command)¶

Live commit of data from overlay image nodes into backing nodes - i.e., writes data between ‘top’ and ‘base’ into ‘base’.

If top == base, that is an error. If top has no overlays on top of it, or if it is in use by a writer, the job will not be completed by itself. The user needs to complete the job with the block-job-complete command after getting the ready event. (Since 2.0)

If the base image is smaller than top, then the base image will be resized to be the same size as top. If top is smaller than the base image, the base will not be truncated. If you want the base image size to match the size of the smaller top, you can safely truncate it yourself once the commit operation successfully completes.

Arguments¶

job-id: string (optional)

identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)

device: string

the device name or node-name of a root node

base-node: string (optional)

The node name of the backing image to write data into. If not specified, this is the deepest backing image. (since: 3.1)

base: string (optional)

Same as base-node, except that it is a file name rather than a node name. This must be the exact filename string that was used to open the node; other strings, even if addressing the same file, are not accepted

top-node: string (optional)

The node name of the backing image within the image chain which contains the topmost data to be committed down. If not specified, this is the active layer. (since: 3.1)

top: string (optional)

Same as top-node, except that it is a file name rather than a node name. This must be the exact filename string that was used to open the node; other strings, even if addressing the same file, are not accepted

backing-file: string (optional)

The backing file string to write into the overlay image of ‘top’. If ‘top’ does not have an overlay image, or if ‘top’ is in use by a writer, specifying a backing file string is an error.

This filename is not validated. If a pathname string is such that it cannot be resolved by QEMU, that means that subsequent QMP or HMP commands must use node-names for the image in question, as filename lookup methods will fail.

If not specified, QEMU will automatically determine the backing file string to use, or error out if there is no obvious choice. Care should be taken when specifying the string, to specify a valid filename or protocol. (Since 2.1)

speed: int (optional)

the maximum speed, in bytes per second

on-error: BlockdevOnError (optional)

the action to take on an error. ‘ignore’ means that the request should be retried. (default: report; Since: 5.0)

filter-node-name: string (optional)

the node name that should be assigned to the filter driver that the commit job inserts into the graph above top. If this option is not given, a node name is autogenerated. (Since: 2.9)

auto-finalize: boolean (optional)

When false, this job will wait in a PENDING state after it has finished its work, waiting for block-job-finalize before making any block graph changes. When true, this job will automatically perform its abort or commit actions. Defaults to true. (Since 3.1)

auto-dismiss: boolean (optional)

When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and awaits block-job-dismiss. When true, this job will automatically disappear from the query list without user intervention. Defaults to true. (Since 3.1)

Features¶

deprecated: Members base and top are deprecated. Use base-node and top-node instead.

Returns¶

Nothing on success
If device does not exist, DeviceNotFound
Any other error returns a GenericError.

Since¶

1.3

Example¶

-> { "execute": "block-commit",
     "arguments": { "device": "virtio0",
                    "top": "/tmp/snap1.qcow2" } }
<- { "return": {} }

`drive-backup` (Command)¶

Start a point-in-time copy of a block device to a new destination. The status of ongoing drive-backup operations can be checked with query-block-jobs where the BlockJobInfo.type field has the value ‘backup’. The operation can be stopped before it has completed using the block-job-cancel command.

Arguments¶

The members of DriveBackup

Returns¶

nothing on success
If device is not a valid block device, GenericError

Since¶

1.6

Example¶

-> { "execute": "drive-backup",
     "arguments": { "device": "drive0",
                    "sync": "full",
                    "target": "backup.img" } }
<- { "return": {} }

`blockdev-backup` (Command)¶

Start a point-in-time copy of a block device to a new destination. The status of ongoing blockdev-backup operations can be checked with query-block-jobs where the BlockJobInfo.type field has the value ‘backup’. The operation can be stopped before it has completed using the block-job-cancel command.

Arguments¶

The members of BlockdevBackup

Returns¶

nothing on success
If device is not a valid block device, DeviceNotFound

Since¶

2.3

Example¶

-> { "execute": "blockdev-backup",
     "arguments": { "device": "src-id",
                    "sync": "full",
                    "target": "tgt-id" } }
<- { "return": {} }

`query-named-block-nodes` (Command)¶

Get the named block driver list

Arguments¶

flat: boolean (optional): Omit the nested data about backing image (“backing-image” key) if true. Default is false (Since 5.0)

Returns¶

the list of BlockDeviceInfo

Since¶

2.0

Example¶

-> { "execute": "query-named-block-nodes" }
<- { "return": [ { "ro":false,
                   "drv":"qcow2",
                   "encrypted":false,
                   "file":"disks/test.qcow2",
                   "node-name": "my-node",
                   "backing_file_depth":1,
                   "bps":1000000,
                   "bps_rd":0,
                   "bps_wr":0,
                   "iops":1000000,
                   "iops_rd":0,
                   "iops_wr":0,
                   "bps_max": 8000000,
                   "bps_rd_max": 0,
                   "bps_wr_max": 0,
                   "iops_max": 0,
                   "iops_rd_max": 0,
                   "iops_wr_max": 0,
                   "iops_size": 0,
                   "write_threshold": 0,
                   "image":{
                      "filename":"disks/test.qcow2",
                      "format":"qcow2",
                      "virtual-size":2048000,
                      "backing_file":"base.qcow2",
                      "full-backing-filename":"disks/base.qcow2",
                      "backing-filename-format":"qcow2",
                      "snapshots":[
                         {
                            "id": "1",
                            "name": "snapshot1",
                            "vm-state-size": 0,
                            "date-sec": 10000200,
                            "date-nsec": 12,
                            "vm-clock-sec": 206,
                            "vm-clock-nsec": 30
                         }
                      ],
                      "backing-image":{
                          "filename":"disks/base.qcow2",
                          "format":"qcow2",
                          "virtual-size":2048000
                      }
                   } } ] }

`XDbgBlockGraphNodeType` (Enum)¶

Values¶

block-backend: corresponds to BlockBackend
block-job: corresponds to BlockJob
block-driver: corresponds to BlockDriverState

Since¶

4.0

`XDbgBlockGraphNode` (Object)¶

Members¶

id: int: Block graph node identifier. This id is generated only for x-debug-query-block-graph and does not relate to any other identifiers in Qemu.
type: XDbgBlockGraphNodeType: Type of graph node. Can be one of block-backend, block-job or block-driver-state.
name: string: Human readable name of the node. Corresponds to node-name for block-driver-state nodes; is not guaranteed to be unique in the whole graph (with block-jobs and block-backends).

Since¶

4.0

`BlockPermission` (Enum)¶

Enum of base block permissions.

Values¶

consistent-read: A user that has the “permission” of consistent reads is guaranteed that their view of the contents of the block device is complete and self-consistent, representing the contents of a disk at a specific point. For most block devices (including their backing files) this is true, but the property cannot be maintained in a few situations like for intermediate nodes of a commit block job.
write: This permission is required to change the visible disk contents.
write-unchanged: This permission (which is weaker than BLK_PERM_WRITE) is both enough and required for writes to the block node when the caller promises that the visible disk content doesn’t change. As the BLK_PERM_WRITE permission is strictly stronger, either is sufficient to perform an unchanging write.
resize: This permission is required to change the size of a block node.
graph-mod: This permission is required to change the node that this BdrvChild points to.

Since¶

4.0

`XDbgBlockGraphEdge` (Object)¶

Block Graph edge description for x-debug-query-block-graph.

Members¶

parent: int: parent id
child: int: child id
name: string: name of the relation (examples are ‘file’ and ‘backing’)
perm: array of BlockPermission: granted permissions for the parent operating on the child
shared-perm: array of BlockPermission: permissions that can still be granted to other users of the child while it is still attached to this parent

Since¶

4.0

`XDbgBlockGraph` (Object)¶

Block Graph - list of nodes and list of edges.

Members¶

nodes: array of XDbgBlockGraphNode: Not documented
edges: array of XDbgBlockGraphEdge: Not documented

Since¶

4.0

`x-debug-query-block-graph` (Command)¶

Get the block graph.

Since¶

4.0

`drive-mirror` (Command)¶

Start mirroring a block device’s writes to a new destination. target specifies the target of the new image. If the file exists, or if it is a device, it will be used as the new destination for writes. If it does not exist, a new file will be created. format specifies the format of the mirror image, default is to probe if mode=’existing’, else the format of the source.

Arguments¶

The members of DriveMirror

Returns¶

nothing on success
If device is not a valid block device, GenericError

Since¶

1.3

Example¶

-> { "execute": "drive-mirror",
     "arguments": { "device": "ide-hd0",
                    "target": "/some/place/my-image",
                    "sync": "full",
                    "format": "qcow2" } }
<- { "return": {} }

`DriveMirror` (Object)¶

A set of parameters describing drive mirror setup.

Members¶

job-id: string (optional): identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)
device: string: the device name or node-name of a root node whose writes should be mirrored.
target: string: the target of the new image. If the file exists, or if it is a device, the existing file/device will be used as the new destination. If it does not exist, a new file will be created.
format: string (optional): the format of the new destination, default is to probe if mode is ‘existing’, else the format of the source
node-name: string (optional): the new block driver state node name in the graph (Since 2.1)
replaces: string (optional): with sync=full graph node name to be replaced by the new image when a whole image copy is done. This can be used to repair broken Quorum files. By default, device is replaced, although implicitly created filters on it are kept. (Since 2.1)
mode: NewImageMode (optional): whether and how QEMU should create a new image, default is ‘absolute-paths’.
speed: int (optional): the maximum speed, in bytes per second
sync: MirrorSyncMode: what parts of the disk image should be copied to the destination (all the disk, only the sectors allocated in the topmost image, or only new I/O).
granularity: int (optional): granularity of the dirty bitmap, default is 64K if the image format doesn’t have clusters, 4K if the clusters are smaller than that, else the cluster size. Must be a power of 2 between 512 and 64M (since 1.4).
buf-size: int (optional): maximum amount of data in flight from source to target (since 1.4).
on-source-error: BlockdevOnError (optional): the action to take on an error on the source, default ‘report’. ‘stop’ and ‘enospc’ can only be used if the block device supports io-status (see BlockInfo).
on-target-error: BlockdevOnError (optional): the action to take on an error on the target, default ‘report’ (no limitations, since this applies to a different block device than device).
unmap: boolean (optional): Whether to try to unmap target sectors where source has only zero. If true, and target unallocated sectors will read as zero, target image sectors will be unmapped; otherwise, zeroes will be written. Both will result in identical contents. Default is true. (Since 2.4)
copy-mode: MirrorCopyMode (optional): when to copy data to the destination; defaults to ‘background’ (Since: 3.0)
auto-finalize: boolean (optional): When false, this job will wait in a PENDING state after it has finished its work, waiting for block-job-finalize before making any block graph changes. When true, this job will automatically perform its abort or commit actions. Defaults to true. (Since 3.1)
auto-dismiss: boolean (optional): When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and awaits block-job-dismiss. When true, this job will automatically disappear from the query list without user intervention. Defaults to true. (Since 3.1)

Since¶

1.3

`BlockDirtyBitmap` (Object)¶

Members¶

node: string: name of device/node which the bitmap is tracking
name: string: name of the dirty bitmap

Since¶

2.4

`BlockDirtyBitmapAdd` (Object)¶

Members¶

node: string: name of device/node which the bitmap is tracking
name: string: name of the dirty bitmap (must be less than 1024 bytes)
granularity: int (optional): the bitmap granularity, default is 64k for block-dirty-bitmap-add
persistent: boolean (optional): the bitmap is persistent, i.e. it will be saved to the corresponding block device image file on its close. For now only Qcow2 disks support persistent bitmaps. Default is false for block-dirty-bitmap-add. (Since: 2.10)
disabled: boolean (optional): the bitmap is created in the disabled state, which means that it will not track drive changes. The bitmap may be enabled with block-dirty-bitmap-enable. Default is false. (Since: 4.0)

Since¶

2.4

`BlockDirtyBitmapMergeSource` (Alternate)¶

Members¶

local: string: name of the bitmap, attached to the same node as target bitmap.
external: BlockDirtyBitmap: bitmap with specified node

Since¶

4.1

`BlockDirtyBitmapMerge` (Object)¶

Members¶

node: string: name of device/node which the target bitmap is tracking
target: string: name of the destination dirty bitmap
bitmaps: array of BlockDirtyBitmapMergeSource: name(s) of the source dirty bitmap(s) at node and/or fully specified BlockDirtyBitmap elements. The latter are supported since 4.1.

Since¶

4.0

`block-dirty-bitmap-add` (Command)¶

Create a dirty bitmap with a name on the node, and start tracking the writes.

Returns¶

nothing on success
If node is not a valid block device or node, DeviceNotFound
If name is already taken, GenericError with an explanation

Since¶

2.4

Example¶

-> { "execute": "block-dirty-bitmap-add",
     "arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }

`block-dirty-bitmap-remove` (Command)¶

Stop write tracking and remove the dirty bitmap that was created with block-dirty-bitmap-add. If the bitmap is persistent, remove it from its storage too.

Returns¶

nothing on success
If node is not a valid block device or node, DeviceNotFound
If name is not found, GenericError with an explanation
if name is frozen by an operation, GenericError

Since¶

2.4

Example¶

-> { "execute": "block-dirty-bitmap-remove",
     "arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }

`block-dirty-bitmap-clear` (Command)¶

Clear (reset) a dirty bitmap on the device, so that an incremental backup from this point in time forward will only backup clusters modified after this clear operation.

Returns¶

nothing on success
If node is not a valid block device, DeviceNotFound
If name is not found, GenericError with an explanation

Since¶

2.4

Example¶

-> { "execute": "block-dirty-bitmap-clear",
     "arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }

`block-dirty-bitmap-enable` (Command)¶

Enables a dirty bitmap so that it will begin tracking disk changes.

Returns¶

nothing on success
If node is not a valid block device, DeviceNotFound
If name is not found, GenericError with an explanation

Since¶

4.0

Example¶

-> { "execute": "block-dirty-bitmap-enable",
     "arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }

`block-dirty-bitmap-disable` (Command)¶

Disables a dirty bitmap so that it will stop tracking disk changes.

Returns¶

nothing on success
If node is not a valid block device, DeviceNotFound
If name is not found, GenericError with an explanation

Since¶

4.0

Example¶

-> { "execute": "block-dirty-bitmap-disable",
     "arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }

`block-dirty-bitmap-merge` (Command)¶

Merge dirty bitmaps listed in bitmaps to the target dirty bitmap. Dirty bitmaps in bitmaps will be unchanged, except if it also appears as the target bitmap. Any bits already set in target will still be set after the merge, i.e., this operation does not clear the target. On error, target is unchanged.

The resulting bitmap will count as dirty any clusters that were dirty in any of the source bitmaps. This can be used to achieve backup checkpoints, or in simpler usages, to copy bitmaps.

Returns¶

nothing on success
If node is not a valid block device, DeviceNotFound
If any bitmap in bitmaps or target is not found, GenericError
If any of the bitmaps have different sizes or granularities, GenericError

Since¶

4.0

Example¶

-> { "execute": "block-dirty-bitmap-merge",
     "arguments": { "node": "drive0", "target": "bitmap0",
                    "bitmaps": ["bitmap1"] } }
<- { "return": {} }

`BlockDirtyBitmapSha256` (Object)¶

SHA256 hash of dirty bitmap data

Members¶

sha256: string: ASCII representation of SHA256 bitmap hash

Since¶

2.10

`x-debug-block-dirty-bitmap-sha256` (Command)¶

Get bitmap SHA256.

Returns¶

BlockDirtyBitmapSha256 on success
If node is not a valid block device, DeviceNotFound
If name is not found or if hashing has failed, GenericError with an explanation

Since¶

2.10

`blockdev-mirror` (Command)¶

Start mirroring a block device’s writes to a new destination.

Arguments¶

job-id: string (optional): identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)
device: string: The device name or node-name of a root node whose writes should be mirrored.
target: string: the id or node-name of the block device to mirror to. This mustn’t be attached to guest.
replaces: string (optional): with sync=full graph node name to be replaced by the new image when a whole image copy is done. This can be used to repair broken Quorum files. By default, device is replaced, although implicitly created filters on it are kept.
speed: int (optional): the maximum speed, in bytes per second
sync: MirrorSyncMode: what parts of the disk image should be copied to the destination (all the disk, only the sectors allocated in the topmost image, or only new I/O).
granularity: int (optional): granularity of the dirty bitmap, default is 64K if the image format doesn’t have clusters, 4K if the clusters are smaller than that, else the cluster size. Must be a power of 2 between 512 and 64M
buf-size: int (optional): maximum amount of data in flight from source to target
on-source-error: BlockdevOnError (optional): the action to take on an error on the source, default ‘report’. ‘stop’ and ‘enospc’ can only be used if the block device supports io-status (see BlockInfo).
on-target-error: BlockdevOnError (optional): the action to take on an error on the target, default ‘report’ (no limitations, since this applies to a different block device than device).
filter-node-name: string (optional): the node name that should be assigned to the filter driver that the mirror job inserts into the graph above device. If this option is not given, a node name is autogenerated. (Since: 2.9)
copy-mode: MirrorCopyMode (optional): when to copy data to the destination; defaults to ‘background’ (Since: 3.0)
auto-finalize: boolean (optional): When false, this job will wait in a PENDING state after it has finished its work, waiting for block-job-finalize before making any block graph changes. When true, this job will automatically perform its abort or commit actions. Defaults to true. (Since 3.1)
auto-dismiss: boolean (optional): When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and awaits block-job-dismiss. When true, this job will automatically disappear from the query list without user intervention. Defaults to true. (Since 3.1)

Returns¶

nothing on success.

Since¶

2.6

Example¶

-> { "execute": "blockdev-mirror",
     "arguments": { "device": "ide-hd0",
                    "target": "target0",
                    "sync": "full" } }
<- { "return": {} }

`BlockIOThrottle` (Object)¶

A set of parameters describing block throttling.

Members¶

device: string (optional): Block device name
id: string (optional): The name or QOM path of the guest device (since: 2.8)
bps: int: total throughput limit in bytes per second
bps_rd: int: read throughput limit in bytes per second
bps_wr: int: write throughput limit in bytes per second
iops: int: total I/O operations per second
iops_rd: int: read I/O operations per second
iops_wr: int: write I/O operations per second
bps_max: int (optional): total throughput limit during bursts, in bytes (Since 1.7)
bps_rd_max: int (optional): read throughput limit during bursts, in bytes (Since 1.7)
bps_wr_max: int (optional): write throughput limit during bursts, in bytes (Since 1.7)
iops_max: int (optional): total I/O operations per second during bursts, in bytes (Since 1.7)
iops_rd_max: int (optional): read I/O operations per second during bursts, in bytes (Since 1.7)
iops_wr_max: int (optional): write I/O operations per second during bursts, in bytes (Since 1.7)
bps_max_length: int (optional): maximum length of the bps_max burst period, in seconds. It must only be set if bps_max is set as well. Defaults to 1. (Since 2.6)
bps_rd_max_length: int (optional): maximum length of the bps_rd_max burst period, in seconds. It must only be set if bps_rd_max is set as well. Defaults to 1. (Since 2.6)
bps_wr_max_length: int (optional): maximum length of the bps_wr_max burst period, in seconds. It must only be set if bps_wr_max is set as well. Defaults to 1. (Since 2.6)
iops_max_length: int (optional): maximum length of the iops burst period, in seconds. It must only be set if iops_max is set as well. Defaults to 1. (Since 2.6)
iops_rd_max_length: int (optional): maximum length of the iops_rd_max burst period, in seconds. It must only be set if iops_rd_max is set as well. Defaults to 1. (Since 2.6)
iops_wr_max_length: int (optional): maximum length of the iops_wr_max burst period, in seconds. It must only be set if iops_wr_max is set as well. Defaults to 1. (Since 2.6)
iops_size: int (optional): an I/O size in bytes (Since 1.7)
group: string (optional): throttle group name (Since 2.4)

Features¶

deprecated: Member device is deprecated. Use id instead.

Since¶

1.1

`ThrottleLimits` (Object)¶

Limit parameters for throttling. Since some limit combinations are illegal, limits should always be set in one transaction. All fields are optional. When setting limits, if a field is missing the current value is not changed.

Members¶

iops-total: int (optional): limit total I/O operations per second
iops-total-max: int (optional): I/O operations burst
iops-total-max-length: int (optional): length of the iops-total-max burst period, in seconds It must only be set if iops-total-max is set as well.
iops-read: int (optional): limit read operations per second
iops-read-max: int (optional): I/O operations read burst
iops-read-max-length: int (optional): length of the iops-read-max burst period, in seconds It must only be set if iops-read-max is set as well.
iops-write: int (optional): limit write operations per second
iops-write-max: int (optional): I/O operations write burst
iops-write-max-length: int (optional): length of the iops-write-max burst period, in seconds It must only be set if iops-write-max is set as well.
bps-total: int (optional): limit total bytes per second
bps-total-max: int (optional): total bytes burst
bps-total-max-length: int (optional): length of the bps-total-max burst period, in seconds. It must only be set if bps-total-max is set as well.
bps-read: int (optional): limit read bytes per second
bps-read-max: int (optional): total bytes read burst
bps-read-max-length: int (optional): length of the bps-read-max burst period, in seconds It must only be set if bps-read-max is set as well.
bps-write: int (optional): limit write bytes per second
bps-write-max: int (optional): total bytes write burst
bps-write-max-length: int (optional): length of the bps-write-max burst period, in seconds It must only be set if bps-write-max is set as well.
iops-size: int (optional): when limiting by iops max size of an I/O in bytes

Since¶

2.11

`ThrottleGroupProperties` (Object)¶

Properties for throttle-group objects.

The options starting with x- are aliases for the same key without x- in the limits object. As indicated by the x- prefix, this is not a stable interface and may be removed or changed incompatibly in the future. Use limits for a supported stable interface.

Members¶

limits: ThrottleLimits (optional): limits to apply for this throttle group
x-iops-total: int (optional): Not documented
x-iops-total-max: int (optional): Not documented
x-iops-total-max-length: int (optional): Not documented
x-iops-read: int (optional): Not documented
x-iops-read-max: int (optional): Not documented
x-iops-read-max-length: int (optional): Not documented
x-iops-write: int (optional): Not documented
x-iops-write-max: int (optional): Not documented
x-iops-write-max-length: int (optional): Not documented
x-bps-total: int (optional): Not documented
x-bps-total-max: int (optional): Not documented
x-bps-total-max-length: int (optional): Not documented
x-bps-read: int (optional): Not documented
x-bps-read-max: int (optional): Not documented
x-bps-read-max-length: int (optional): Not documented
x-bps-write: int (optional): Not documented
x-bps-write-max: int (optional): Not documented
x-bps-write-max-length: int (optional): Not documented
x-iops-size: int (optional): Not documented

Since¶

2.11

`block-stream` (Command)¶

Copy data from a backing file into a block device.

The block streaming operation is performed in the background until the entire backing file has been copied. This command returns immediately once streaming has started. The status of ongoing block streaming operations can be checked with query-block-jobs. The operation can be stopped before it has completed using the block-job-cancel command.

The node that receives the data is called the top image, can be located in any part of the chain (but always above the base image; see below) and can be specified using its device or node name. Earlier qemu versions only allowed ‘device’ to name the top level node; presence of the ‘base-node’ parameter during introspection can be used as a witness of the enhanced semantics of ‘device’.

If a base file is specified then sectors are not copied from that base file and its backing chain. This can be used to stream a subset of the backing file chain instead of flattening the entire image. When streaming completes the image file will have the base file as its backing file, unless that node was changed while the job was running. In that case, base’s parent’s backing (or filtered, whichever exists) child (i.e., base at the beginning of the job) will be the new backing file.

On successful completion the image file is updated to drop the backing file and the BLOCK_JOB_COMPLETED event is emitted.

In case device is a filter node, block-stream modifies the first non-filter overlay node below it to point to the new backing node instead of modifying device itself.

Arguments¶

job-id: string (optional)

identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)

device: string

the device or node name of the top image

base: string (optional)

the common backing file name. It cannot be set if base-node or bottom is also set.

base-node: string (optional)

the node name of the backing file. It cannot be set if base or bottom is also set. (Since 2.8)

bottom: string (optional)

the last node in the chain that should be streamed into top. It cannot be set if base or base-node is also set. It cannot be filter node. (Since 6.0)

backing-file: string (optional)

The backing file string to write into the top image. This filename is not validated.

If a pathname string is such that it cannot be resolved by QEMU, that means that subsequent QMP or HMP commands must use node-names for the image in question, as filename lookup methods will fail.

If not specified, QEMU will automatically determine the backing file string to use, or error out if there is no obvious choice. Care should be taken when specifying the string, to specify a valid filename or protocol. (Since 2.1)

speed: int (optional)

the maximum speed, in bytes per second

on-error: BlockdevOnError (optional)

the action to take on an error (default report). ‘stop’ and ‘enospc’ can only be used if the block device supports io-status (see BlockInfo). Since 1.3.

filter-node-name: string (optional)

the node name that should be assigned to the filter driver that the stream job inserts into the graph above device. If this option is not given, a node name is autogenerated. (Since: 6.0)

auto-finalize: boolean (optional)

When false, this job will wait in a PENDING state after it has finished its work, waiting for block-job-finalize before making any block graph changes. When true, this job will automatically perform its abort or commit actions. Defaults to true. (Since 3.1)

auto-dismiss: boolean (optional)

When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and awaits block-job-dismiss. When true, this job will automatically disappear from the query list without user intervention. Defaults to true. (Since 3.1)

Returns¶

Nothing on success.
If device does not exist, DeviceNotFound.

Since¶

1.1

Example¶

-> { "execute": "block-stream",
     "arguments": { "device": "virtio0",
                    "base": "/tmp/master.qcow2" } }
<- { "return": {} }

`block-job-set-speed` (Command)¶

Set maximum speed for a background block operation.

This command can only be issued when there is an active block job.

Throttling can be disabled by setting the speed to 0.

Arguments¶

device: string: The job identifier. This used to be a device name (hence the name of the parameter), but since QEMU 2.7 it can have other values.
speed: int: the maximum speed, in bytes per second, or 0 for unlimited. Defaults to 0.

Returns¶

Nothing on success
If no background operation is active on this device, DeviceNotActive

Since¶

1.1

`block-job-cancel` (Command)¶

Stop an active background block operation.

This command returns immediately after marking the active background block operation for cancellation. It is an error to call this command if no operation is in progress.

The operation will cancel as soon as possible and then emit the BLOCK_JOB_CANCELLED event. Before that happens the job is still visible when enumerated using query-block-jobs.

Note that if you issue ‘block-job-cancel’ after ‘drive-mirror’ has indicated (via the event BLOCK_JOB_READY) that the source and destination are synchronized, then the event triggered by this command changes to BLOCK_JOB_COMPLETED, to indicate that the mirroring has ended and the destination now has a point-in-time copy tied to the time of the cancellation.

For streaming, the image file retains its backing file unless the streaming operation happens to complete just as it is being cancelled. A new streaming operation can be started at a later time to finish copying all data from the backing file.

Arguments¶

device: string: The job identifier. This used to be a device name (hence the name of the parameter), but since QEMU 2.7 it can have other values.
force: boolean (optional): If true, and the job has already emitted the event BLOCK_JOB_READY, abandon the job immediately (even if it is paused) instead of waiting for the destination to complete its final synchronization (since 1.3)

Returns¶

Nothing on success
If no background operation is active on this device, DeviceNotActive

Since¶

1.1

`block-job-pause` (Command)¶

Pause an active background block operation.

This command returns immediately after marking the active background block operation for pausing. It is an error to call this command if no operation is in progress or if the job is already paused.

The operation will pause as soon as possible. No event is emitted when the operation is actually paused. Cancelling a paused job automatically resumes it.

Arguments¶

device: string: The job identifier. This used to be a device name (hence the name of the parameter), but since QEMU 2.7 it can have other values.

Returns¶

Nothing on success
If no background operation is active on this device, DeviceNotActive

Since¶

1.3

`block-job-resume` (Command)¶

Resume an active background block operation.

This command returns immediately after resuming a paused background block operation. It is an error to call this command if no operation is in progress or if the job is not paused.

This command also clears the error status of the job.

Arguments¶

device: string: The job identifier. This used to be a device name (hence the name of the parameter), but since QEMU 2.7 it can have other values.

Returns¶

Nothing on success
If no background operation is active on this device, DeviceNotActive

Since¶

1.3

`block-job-complete` (Command)¶

Manually trigger completion of an active background block operation. This is supported for drive mirroring, where it also switches the device to write to the target path only. The ability to complete is signaled with a BLOCK_JOB_READY event.

This command completes an active background block operation synchronously. The ordering of this command’s return with the BLOCK_JOB_COMPLETED event is not defined. Note that if an I/O error occurs during the processing of this command: 1) the command itself will fail; 2) the error will be processed according to the rerror/werror arguments that were specified when starting the operation.

A cancelled or paused job cannot be completed.

Arguments¶

device: string: The job identifier. This used to be a device name (hence the name of the parameter), but since QEMU 2.7 it can have other values.

Returns¶

Nothing on success
If no background operation is active on this device, DeviceNotActive

Since¶

1.3

`block-job-dismiss` (Command)¶

For jobs that have already concluded, remove them from the block-job-query list. This command only needs to be run for jobs which were started with QEMU 2.12+ job lifetime management semantics.

This command will refuse to operate on any job that has not yet reached its terminal state, JOB_STATUS_CONCLUDED. For jobs that make use of the BLOCK_JOB_READY event, block-job-cancel or block-job-complete will still need to be used as appropriate.

Arguments¶

id: string: The job identifier.

`BlockdevOptionsFile` (Object)¶

Driver specific block device options for the file backend.

Members¶

filename: string: path to the image file
pr-manager: string (optional): the id for the object that will handle persistent reservations for this device (default: none, forward the commands via SG_IO; since 2.11)
aio: BlockdevAioOptions (optional): AIO backend (default: threads) (since: 2.8)
locking: OnOffAuto (optional): whether to enable file locking. If set to ‘auto’, only enable when Open File Descriptor (OFD) locking API is available (default: auto, since 2.10)
drop-cache: boolean (optional) (If: defined(CONFIG_LINUX)): invalidate page cache during live migration. This prevents stale data on the migration destination with cache.direct=off. Currently only supported on Linux hosts. (default: on, since: 4.0)
x-check-cache-dropped: boolean (optional): whether to check that page cache was dropped on live migration. May cause noticeable delays if the image file is large, do not use in production. (default: off) (since: 3.0)

Features¶

dynamic-auto-read-only: If present, enabled auto-read-only means that the driver will open the image read-only at first, dynamically reopen the image file read-write when the first writer is attached to the node and reopen read-only when the last writer is detached. This allows giving QEMU write permissions only on demand when an operation actually needs write access.

Since¶

2.9

`BlockdevOptionsNull` (Object)¶

Driver specific block device options for the null backend.

Members¶

size: int (optional): size of the device in bytes.
latency-ns: int (optional): emulated latency (in nanoseconds) in processing requests. Default to zero which completes requests immediately. (Since 2.4)
read-zeroes: boolean (optional): if true, reads from the device produce zeroes; if false, the buffer is left unchanged. (default: false; since: 4.1)

Since¶

2.9

`BlockdevOptionsNVMe` (Object)¶

Driver specific block device options for the NVMe backend.

Members¶

device: string: PCI controller address of the NVMe device in format hhhh:bb:ss.f (host:bus:slot.function)
namespace: int: namespace number of the device, starting from 1.

flags: Qcow2OverlapCheckFlags: set of flags for separate specification of each metadata structure type
mode: Qcow2OverlapCheckMode: named mode which chooses a specific set of flags

Since¶

2.9

`BlockdevQcowEncryptionFormat` (Enum)¶

Values¶

aes: AES-CBC with plain64 initialization vectors

Since¶

2.10

`BlockdevQcowEncryption` (Object)¶

Members¶

format: BlockdevQcowEncryptionFormat: Not documented
The members of QCryptoBlockOptionsQCow when format is "aes"

Since¶

2.10

`BlockdevOptionsQcow` (Object)¶

Driver specific block device options for qcow.

Members¶

encrypt: BlockdevQcowEncryption (optional): Image decryption options. Mandatory for encrypted images, except when doing a metadata-only probe of the image.
The members of BlockdevOptionsGenericCOWFormat

Since¶

2.10

`BlockdevQcow2EncryptionFormat` (Enum)¶

Values¶

aes: AES-CBC with plain64 initialization vectors
luks: Not documented

Since¶

2.10

`BlockdevQcow2Encryption` (Object)¶

Members¶

format: BlockdevQcow2EncryptionFormat: Not documented
The members of QCryptoBlockOptionsQCow when format is "aes"
The members of QCryptoBlockOptionsLUKS when format is "luks"

Since¶

2.10

`BlockdevOptionsPreallocate` (Object)¶

Filter driver intended to be inserted between format and protocol node and do preallocation in protocol node on write.

Members¶

prealloc-align: int (optional): on preallocation, align file length to this number, default 1048576 (1M)
prealloc-size: int (optional): how much to preallocate, default 134217728 (128M)
The members of BlockdevOptionsGenericFormat

Since¶

6.0

`BlockdevOptionsQcow2` (Object)¶

Driver specific block device options for qcow2.

Members¶

lazy-refcounts: boolean (optional): whether to enable the lazy refcounts feature (default is taken from the image file)
pass-discard-request: boolean (optional): whether discard requests to the qcow2 device should be forwarded to the data source
pass-discard-snapshot: boolean (optional): whether discard requests for the data source should be issued when a snapshot operation (e.g. deleting a snapshot) frees clusters in the qcow2 file
pass-discard-other: boolean (optional): whether discard requests for the data source should be issued on other occasions where a cluster gets freed
overlap-check: Qcow2OverlapChecks (optional): which overlap checks to perform for writes to the image, defaults to ‘cached’ (since 2.2)
cache-size: int (optional): the maximum total size of the L2 table and refcount block caches in bytes (since 2.2)
l2-cache-size: int (optional): the maximum size of the L2 table cache in bytes (since 2.2)
l2-cache-entry-size: int (optional): the size of each entry in the L2 cache in bytes. It must be a power of two between 512 and the cluster size. The default value is the cluster size (since 2.12)
refcount-cache-size: int (optional): the maximum size of the refcount block cache in bytes (since 2.2)
cache-clean-interval: int (optional): clean unused entries in the L2 and refcount caches. The interval is in seconds. The default value is 600 on supporting platforms, and 0 on other platforms. 0 disables this feature. (since 2.5)
encrypt: BlockdevQcow2Encryption (optional): Image decryption options. Mandatory for encrypted images, except when doing a metadata-only probe of the image. (since 2.10)
data-file: BlockdevRef (optional): reference to or definition of the external data file. This may only be specified for images that require an external data file. If it is not specified for such an image, the data file name is loaded from the image file. (since 4.0)
The members of BlockdevOptionsGenericCOWFormat

Since¶

2.9

`SshHostKeyCheckMode` (Enum)¶

Values¶

none: Don’t check the host key at all
hash: Compare the host key with a given hash
known_hosts: Check the host key against the known_hosts file

Since¶

2.12

`SshHostKeyCheckHashType` (Enum)¶

Values¶

md5: The given hash is an md5 hash
sha1: The given hash is an sha1 hash

Since¶

2.12

`SshHostKeyHash` (Object)¶

Members¶

type: SshHostKeyCheckHashType: The hash algorithm used for the hash
hash: string: The expected hash value

Since¶

2.12

`SshHostKeyCheck` (Object)¶

Members¶

mode: SshHostKeyCheckMode: Not documented
The members of SshHostKeyHash when mode is "hash"

Since¶

2.12

`BlockdevOptionsSsh` (Object)¶

Members¶

server: InetSocketAddress: host address
path: string: path to the image on the host
user: string (optional): user as which to connect, defaults to current local user name
host-key-check: SshHostKeyCheck (optional): Defines how and what to check the host key against (default: known_hosts)

Since¶

2.9

`BlkdebugEvent` (Enum)¶

Trigger events supported by blkdebug.

Values¶

l1_shrink_write_table: write zeros to the l1 table to shrink image. (since 2.11)
l1_shrink_free_l2_clusters: discard the l2 tables. (since 2.11)
cor_write: a write due to copy-on-read (since 2.11)
cluster_alloc_space: an allocation of file space for a cluster (since 4.1)
none: triggers once at creation of the blkdebug node (since 4.1)
l1_update: Not documented
l1_grow_alloc_table: Not documented
l1_grow_write_table: Not documented
l1_grow_activate_table: Not documented
l2_load: Not documented
l2_update: Not documented
l2_update_compressed: Not documented
l2_alloc_cow_read: Not documented
l2_alloc_write: Not documented
read_aio: Not documented
read_backing_aio: Not documented
read_compressed: Not documented
write_aio: Not documented
write_compressed: Not documented
vmstate_load: Not documented
vmstate_save: Not documented
cow_read: Not documented
cow_write: Not documented
reftable_load: Not documented
reftable_grow: Not documented
reftable_update: Not documented
refblock_load: Not documented
refblock_update: Not documented
refblock_update_part: Not documented
refblock_alloc: Not documented
refblock_alloc_hookup: Not documented
refblock_alloc_write: Not documented
refblock_alloc_write_blocks: Not documented
refblock_alloc_write_table: Not documented
refblock_alloc_switch_table: Not documented
cluster_alloc: Not documented
cluster_alloc_bytes: Not documented
cluster_free: Not documented
flush_to_os: Not documented
flush_to_disk: Not documented
pwritev_rmw_head: Not documented
pwritev_rmw_after_head: Not documented
pwritev_rmw_tail: Not documented
pwritev_rmw_after_tail: Not documented
pwritev: Not documented
pwritev_zero: Not documented
pwritev_done: Not documented
empty_image_prepare: Not documented

Since¶

2.9

`BlkdebugIOType` (Enum)¶

Kinds of I/O that blkdebug can inject errors in.

Values¶

read: .bdrv_co_preadv()
write: .bdrv_co_pwritev()
write-zeroes: .bdrv_co_pwrite_zeroes()
discard: .bdrv_co_pdiscard()
flush: .bdrv_co_flush_to_disk()
block-status: .bdrv_co_block_status()

Since¶

4.1

`BlkdebugInjectErrorOptions` (Object)¶

Describes a single error injection for blkdebug.

Members¶

event: BlkdebugEvent: trigger event
state: int (optional): the state identifier blkdebug needs to be in to actually trigger the event; defaults to “any”
iotype: BlkdebugIOType (optional): the type of I/O operations on which this error should be injected; defaults to “all read, write, write-zeroes, discard, and flush operations” (since: 4.1)
errno: int (optional): error identifier (errno) to be returned; defaults to EIO
sector: int (optional): specifies the sector index which has to be affected in order to actually trigger the event; defaults to “any sector”
once: boolean (optional): disables further events after this one has been triggered; defaults to false
immediately: boolean (optional): fail immediately; defaults to false

Since¶

2.9

`BlkdebugSetStateOptions` (Object)¶

Describes a single state-change event for blkdebug.

Members¶

event: BlkdebugEvent: trigger event
state: int (optional): the current state identifier blkdebug needs to be in; defaults to “any”
new_state: int: the state identifier blkdebug is supposed to assume if this event is triggered

Since¶

2.9

`BlockdevOptionsBlkdebug` (Object)¶

Driver specific block device options for blkdebug.

Members¶

image: BlockdevRef: underlying raw block device (or image file)
config: string (optional): filename of the configuration file
align: int (optional): required alignment for requests in bytes, must be positive power of 2, or 0 for default
max-transfer: int (optional): maximum size for I/O transfers in bytes, must be positive multiple of align and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (since 2.10)
opt-write-zero: int (optional): preferred alignment for write zero requests in bytes, must be positive multiple of align and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (since 2.10)
max-write-zero: int (optional): maximum size for write zero requests in bytes, must be positive multiple of align, of opt-write-zero, and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (since 2.10)
opt-discard: int (optional): preferred alignment for discard requests in bytes, must be positive multiple of align and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (since 2.10)
max-discard: int (optional): maximum size for discard requests in bytes, must be positive multiple of align, of opt-discard, and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (since 2.10)
inject-error: array of BlkdebugInjectErrorOptions (optional): array of error injection descriptions
set-state: array of BlkdebugSetStateOptions (optional): array of state-change descriptions
take-child-perms: array of BlockPermission (optional): Permissions to take on image in addition to what is necessary anyway (which depends on how the blkdebug node is used). Defaults to none. (since 5.0)
unshare-child-perms: array of BlockPermission (optional): Permissions not to share on image in addition to what cannot be shared anyway (which depends on how the blkdebug node is used). Defaults to none. (since 5.0)

Since¶

2.9

`BlockdevOptionsBlklogwrites` (Object)¶

Driver specific block device options for blklogwrites.

Members¶

file: BlockdevRef: block device
log: BlockdevRef: block device used to log writes to file
log-sector-size: int (optional): sector size used in logging writes to file, determines granularity of offsets and sizes of writes (default: 512)
log-append: boolean (optional): append to an existing log (default: false)
log-super-update-interval: int (optional): interval of write requests after which the log super block is updated to disk (default: 4096)

Since¶

3.0

`BlockdevOptionsBlkverify` (Object)¶

Driver specific block device options for blkverify.

Members¶

test: BlockdevRef: block device to be tested
raw: BlockdevRef: raw image used for verification

Since¶

2.9

`BlockdevOptionsBlkreplay` (Object)¶

Driver specific block device options for blkreplay.

Members¶

image: BlockdevRef: disk image which should be controlled with blkreplay

Since¶

4.2

`QuorumReadPattern` (Enum)¶

An enumeration of quorum read patterns.

Values¶

quorum: read all the children and do a quorum vote on reads
fifo: read only from the first child that has not failed

Since¶

2.9

`BlockdevOptionsQuorum` (Object)¶

Driver specific block device options for Quorum

Members¶

blkverify: boolean (optional)

true if the driver must print content mismatch: set to false by default

children: array of BlockdevRef

the children block devices to use

vote-threshold: int

the vote limit under which a read will fail

rewrite-corrupted: boolean (optional)

rewrite corrupted data when quorum is reached (Since 2.1)

read-pattern: QuorumReadPattern (optional)

crc32c: Not documented
none: Not documented
crc32c-none: Not documented
none-crc32c: Not documented

Since¶

2.9

`BlockdevOptionsIscsi` (Object)¶

Members¶

transport: IscsiTransport: The iscsi transport type
portal: string: The address of the iscsi portal
target: string: The target iqn name
lun: int (optional): LUN to connect to. Defaults to 0.
user: string (optional): User name to log in with. If omitted, no CHAP authentication is performed.
password-secret: string (optional): The ID of a QCryptoSecret object providing the password for the login. This option is required if user is specified.
initiator-name: string (optional): The iqn name we want to identify to the target as. If this option is not specified, an initiator name is generated automatically.
header-digest: IscsiHeaderDigest (optional): The desired header digest. Defaults to none-crc32c.
timeout: int (optional): Timeout in seconds after which a request will timeout. 0 means no timeout and is the default.

Driver specific block device options for iscsi

Since¶

2.9

`RbdAuthMode` (Enum)¶

Values¶

cephx: Not documented
none: Not documented

Since¶

3.0

`BlockdevOptionsRbd` (Object)¶

Members¶

pool: string: Ceph pool name.
namespace: string (optional): Rados namespace name in the Ceph pool. (Since 5.0)
image: string: Image name in the Ceph pool.
conf: string (optional): path to Ceph configuration file. Values in the configuration file will be overridden by options specified via QAPI.
snapshot: string (optional): Ceph snapshot name.
user: string (optional): Ceph id name.
auth-client-required: array of RbdAuthMode (optional): Acceptable authentication modes. This maps to Ceph configuration option “auth_client_required”. (Since 3.0)
key-secret: string (optional): ID of a QCryptoSecret object providing a key for cephx authentication. This maps to Ceph configuration option “key”. (Since 3.0)
server: array of InetSocketAddressBase (optional): Monitor host address and port. This maps to the “mon_host” Ceph option.

Since¶

2.9

`ReplicationMode` (Enum)¶

An enumeration of replication modes.

Values¶

primary: Primary mode, the vm’s state will be sent to secondary QEMU.
secondary: Secondary mode, receive the vm’s state from primary QEMU.

`BlockdevOptions` (Object)¶

Options for creating a block device. Many options are available for all block devices, independent of the block driver:

Members¶

driver: BlockdevDriver: block driver name
node-name: string (optional): the node name of the new node (Since 2.0). This option is required on the top level of blockdev-add. Valid node names start with an alphabetic character and may contain only alphanumeric characters, ‘-‘, ‘.’ and ‘_’. Their maximum length is 31 characters.
discard: BlockdevDiscardOptions (optional): discard-related options (default: ignore)
cache: BlockdevCacheOptions (optional): cache-related options
read-only: boolean (optional): whether the block device should be read-only (default: false). Note that some block drivers support only read-only access, either generally or in certain configurations. In this case, the default value does not work and the option must be specified explicitly.
auto-read-only: boolean (optional): if true and read-only is false, QEMU may automatically decide not to open the image read-write as requested, but fall back to read-only instead (and switch between the modes later), e.g. depending on whether the image file is writable or whether a writing user is attached to the node (default: false, since 3.1)
detect-zeroes: BlockdevDetectZeroesOptions (optional): detect and optimize zero writes (Since 2.1) (default: off)
force-share: boolean (optional): force share all permission on added nodes. Requires read-only=true. (Since 2.10)
The members of BlockdevOptionsBlkdebug when driver is "blkdebug"
The members of BlockdevOptionsBlklogwrites when driver is "blklogwrites"
The members of BlockdevOptionsBlkverify when driver is "blkverify"
The members of BlockdevOptionsBlkreplay when driver is "blkreplay"
The members of BlockdevOptionsGenericFormat when driver is "bochs"
The members of BlockdevOptionsGenericFormat when driver is "cloop"
The members of BlockdevOptionsGenericFormat when driver is "compress"
The members of BlockdevOptionsCor when driver is "copy-on-read"
The members of BlockdevOptionsGenericFormat when driver is "dmg"
The members of BlockdevOptionsFile when driver is "file"
The members of BlockdevOptionsCurlFtp when driver is "ftp"
The members of BlockdevOptionsCurlFtps when driver is "ftps"
The members of BlockdevOptionsGluster when driver is "gluster"
The members of BlockdevOptionsFile when driver is "host_cdrom"
The members of BlockdevOptionsFile when driver is "host_device"
The members of BlockdevOptionsCurlHttp when driver is "http"
The members of BlockdevOptionsCurlHttps when driver is "https"
The members of BlockdevOptionsIscsi when driver is "iscsi"
The members of BlockdevOptionsLUKS when driver is "luks"
The members of BlockdevOptionsNbd when driver is "nbd"
The members of BlockdevOptionsNfs when driver is "nfs"
The members of BlockdevOptionsNull when driver is "null-aio"
The members of BlockdevOptionsNull when driver is "null-co"
The members of BlockdevOptionsNVMe when driver is "nvme"
The members of BlockdevOptionsGenericFormat when driver is "parallels"
The members of BlockdevOptionsPreallocate when driver is "preallocate"
The members of BlockdevOptionsQcow2 when driver is "qcow2"
The members of BlockdevOptionsQcow when driver is "qcow"
The members of BlockdevOptionsGenericCOWFormat when driver is "qed"
The members of BlockdevOptionsQuorum when driver is "quorum"
The members of BlockdevOptionsRaw when driver is "raw"
The members of BlockdevOptionsRbd when driver is "rbd"
The members of BlockdevOptionsReplication when driver is "replication" (If: defined(CONFIG_REPLICATION))
The members of BlockdevOptionsSsh when driver is "ssh"
The members of BlockdevOptionsThrottle when driver is "throttle"
The members of BlockdevOptionsGenericFormat when driver is "vdi"
The members of BlockdevOptionsGenericFormat when driver is "vhdx"
The members of BlockdevOptionsGenericCOWFormat when driver is "vmdk"
The members of BlockdevOptionsGenericFormat when driver is "vpc"
The members of BlockdevOptionsVVFAT when driver is "vvfat"

The members of BlockdevOptions

Since¶

2.9

Example¶

1.
-> { "execute": "blockdev-add",
     "arguments": {
          "driver": "qcow2",
          "node-name": "test1",
          "file": {
              "driver": "file",
              "filename": "test.qcow2"
           }
      }
    }
<- { "return": {} }

2.
-> { "execute": "blockdev-add",
     "arguments": {
          "driver": "qcow2",
          "node-name": "node0",
          "discard": "unmap",
          "cache": {
             "direct": true
           },
           "file": {
             "driver": "file",
             "filename": "/tmp/test.qcow2"
           },
           "backing": {
              "driver": "raw",
              "file": {
                 "driver": "file",
                 "filename": "/dev/fdset/4"
               }
           }
       }
     }

<- { "return": {} }

`x-blockdev-reopen` (Command)¶

Reopens a block device using the given set of options. Any option not specified will be reset to its default value regardless of its previous status. If an option cannot be changed or a particular driver does not support reopening then the command will return an error.

The top-level node-name option (from BlockdevOptions) must be specified and is used to select the block device to be reopened. Other node-name options must be either omitted or set to the current name of the appropriate node. This command won’t change any node name and any attempt to do it will result in an error.

In the case of options that refer to child nodes, the behavior of this command depends on the value:

A set of options (BlockdevOptions): the child is reopened with the specified set of options.

A reference to the current child: the child is reopened using its existing set of options.

A reference to a different node: the current child is replaced with the specified one.

NULL: the current child (if any) is detached.

Options (1) and (2) are supported in all cases, but at the moment only backing allows replacing or detaching an existing child.

Unlike with blockdev-add, the backing option must always be present unless the node being reopened does not have a backing file and its image does not have a default backing file name as part of its metadata.

Arguments¶

The members of BlockdevOptions

Since¶

4.0

`blockdev-del` (Command)¶

Deletes a block device that has been added using blockdev-add. The command will fail if the node is attached to a device or is otherwise being used.

Arguments¶

node-name: string: Name of the graph node to delete.

Since¶

2.9

Example¶

-> { "execute": "blockdev-add",
     "arguments": {
          "driver": "qcow2",
          "node-name": "node0",
          "file": {
              "driver": "file",
              "filename": "test.qcow2"
          }
     }
   }
<- { "return": {} }

-> { "execute": "blockdev-del",
     "arguments": { "node-name": "node0" }
   }
<- { "return": {} }

`BlockdevCreateOptionsFile` (Object)¶

Driver specific image creation options for file.

Members¶

filename: string: Filename for the new image file
size: int: Size of the virtual disk in bytes
preallocation: PreallocMode (optional): Preallocation mode for the new image (default: off; allowed values: off, falloc (if defined CONFIG_POSIX_FALLOCATE), full (if defined CONFIG_POSIX))
nocow: boolean (optional): Turn off copy-on-write (valid only on btrfs; default: off)
extent-size-hint: int (optional): Extent size hint to add to the image file; 0 for not adding an extent size hint (default: 1 MB, since 5.1)

Since¶

2.12

`BlockdevCreateOptionsGluster` (Object)¶

Driver specific image creation options for gluster.

Members¶

location: BlockdevOptionsGluster: Where to store the new image file
size: int: Size of the virtual disk in bytes
preallocation: PreallocMode (optional): Preallocation mode for the new image (default: off; allowed values: off, falloc (if defined CONFIG_GLUSTERFS_FALLOCATE), full (if defined CONFIG_GLUSTERFS_ZEROFILL))

Since¶

2.12

`BlockdevCreateOptionsLUKS` (Object)¶

Driver specific image creation options for LUKS.

Members¶

file: BlockdevRef: Node to create the image format on
size: int: Size of the virtual disk in bytes
preallocation: PreallocMode (optional): Preallocation mode for the new image (since: 4.2) (default: off; allowed values: off, metadata, falloc, full)
The members of QCryptoBlockCreateOptionsLUKS

Since¶

2.12

`BlockdevCreateOptionsNfs` (Object)¶

Driver specific image creation options for NFS.

Members¶

location: BlockdevOptionsNfs: Where to store the new image file
size: int: Size of the virtual disk in bytes

Since¶

2.12

`BlockdevCreateOptionsParallels` (Object)¶

Driver specific image creation options for parallels.

Members¶

file: BlockdevRef: Node to create the image format on
size: int: Size of the virtual disk in bytes
cluster-size: int (optional): Cluster size in bytes (default: 1 MB)

Since¶

2.12

`BlockdevCreateOptionsQcow` (Object)¶

Driver specific image creation options for qcow.

Members¶

file: BlockdevRef: Node to create the image format on
size: int: Size of the virtual disk in bytes
backing-file: string (optional): File name of the backing file if a backing file should be used
encrypt: QCryptoBlockCreateOptions (optional): Encryption options if the image should be encrypted

Since¶

2.12

`BlockdevQcow2Version` (Enum)¶

Values¶

v2: The original QCOW2 format as introduced in qemu 0.10 (version 2)
v3: The extended QCOW2 format as introduced in qemu 1.1 (version 3)

Since¶

2.12

`Qcow2CompressionType` (Enum)¶

Compression type used in qcow2 image file

Values¶

zlib: zlib compression, see <http://zlib.net/>
zstd (If: defined(CONFIG_ZSTD)): zstd compression, see <http://github.com/facebook/zstd>

Since¶

5.1

`BlockdevCreateOptionsQcow2` (Object)¶

Driver specific image creation options for qcow2.

Members¶

file: BlockdevRef: Node to create the image format on
data-file: BlockdevRef (optional): Node to use as an external data file in which all guest data is stored so that only metadata remains in the qcow2 file (since: 4.0)
data-file-raw: boolean (optional): True if the external data file must stay valid as a standalone (read-only) raw image without looking at qcow2 metadata (default: false; since: 4.0)
extended-l2: boolean (optional): True to make the image have extended L2 entries (default: false; since 5.2)
size: int: Size of the virtual disk in bytes
version: BlockdevQcow2Version (optional): Compatibility level (default: v3)
backing-file: string (optional): File name of the backing file if a backing file should be used
backing-fmt: BlockdevDriver (optional): Name of the block driver to use for the backing file
encrypt: QCryptoBlockCreateOptions (optional): Encryption options if the image should be encrypted
cluster-size: int (optional): qcow2 cluster size in bytes (default: 65536)
preallocation: PreallocMode (optional): Preallocation mode for the new image (default: off; allowed values: off, falloc, full, metadata)
lazy-refcounts: boolean (optional): True if refcounts may be updated lazily (default: off)
refcount-bits: int (optional): Width of reference counts in bits (default: 16)
compression-type: Qcow2CompressionType (optional): The image cluster compression method (default: zlib, since 5.1)

Since¶

2.12

`BlockdevCreateOptionsQed` (Object)¶

Driver specific image creation options for qed.

Members¶

file: BlockdevRef: Node to create the image format on
size: int: Size of the virtual disk in bytes
backing-file: string (optional): File name of the backing file if a backing file should be used
backing-fmt: BlockdevDriver (optional): Name of the block driver to use for the backing file
cluster-size: int (optional): Cluster size in bytes (default: 65536)
table-size: int (optional): L1/L2 table size (in clusters)

Since¶

2.12

`BlockdevCreateOptionsRbd` (Object)¶

Driver specific image creation options for rbd/Ceph.

Members¶

location: BlockdevOptionsRbd: Where to store the new image file. This location cannot point to a snapshot.
size: int: Size of the virtual disk in bytes
cluster-size: int (optional): RBD object size

Since¶

2.12

`BlockdevVmdkSubformat` (Enum)¶

Subformat options for VMDK images

Values¶

monolithicSparse: Single file image with sparse cluster allocation
monolithicFlat: Single flat data image and a descriptor file
twoGbMaxExtentSparse: Data is split into 2GB (per virtual LBA) sparse extent files, in addition to a descriptor file
twoGbMaxExtentFlat: Data is split into 2GB (per virtual LBA) flat extent files, in addition to a descriptor file
streamOptimized: Single file image sparse cluster allocation, optimized for streaming over network.

Since¶

4.0

`BlockdevVmdkAdapterType` (Enum)¶

Adapter type info for VMDK images

Values¶

ide: Not documented
buslogic: Not documented
lsilogic: Not documented
legacyESX: Not documented

Since¶

4.0

`BlockdevCreateOptionsVmdk` (Object)¶

Driver specific image creation options for VMDK.

Members¶

file: BlockdevRef: Where to store the new image file. This refers to the image file for monolithcSparse and streamOptimized format, or the descriptor file for other formats.
size: int: Size of the virtual disk in bytes
extents: array of BlockdevRef (optional): Where to store the data extents. Required for monolithcFlat, twoGbMaxExtentSparse and twoGbMaxExtentFlat formats. For monolithicFlat, only one entry is required; for twoGbMaxExtent* formats, the number of entries required is calculated as extent_number = virtual_size / 2GB. Providing more extents than will be used is an error.
subformat: BlockdevVmdkSubformat (optional): The subformat of the VMDK image. Default: “monolithicSparse”.
backing-file: string (optional): The path of backing file. Default: no backing file is used.
adapter-type: BlockdevVmdkAdapterType (optional): The adapter type used to fill in the descriptor. Default: ide.
hwversion: string (optional): Hardware version. The meaningful options are “4” or “6”. Default: “4”.
zeroed-grain: boolean (optional): Whether to enable zeroed-grain feature for sparse subformats. Default: false.

Since¶

4.0

`BlockdevCreateOptionsSsh` (Object)¶

Driver specific image creation options for SSH.

Members¶

location: BlockdevOptionsSsh: Where to store the new image file
size: int: Size of the virtual disk in bytes

Since¶

2.12

`BlockdevCreateOptionsVdi` (Object)¶

Driver specific image creation options for VDI.

Members¶

file: BlockdevRef: Node to create the image format on
size: int: Size of the virtual disk in bytes
preallocation: PreallocMode (optional): Preallocation mode for the new image (default: off; allowed values: off, metadata)

Since¶

2.12

`BlockdevVhdxSubformat` (Enum)¶

Values¶

dynamic: Growing image file
fixed: Preallocated fixed-size image file

Since¶

2.12

`BlockdevCreateOptionsVhdx` (Object)¶

Driver specific image creation options for vhdx.

Members¶

file: BlockdevRef: Node to create the image format on
size: int: Size of the virtual disk in bytes
log-size: int (optional): Log size in bytes, must be a multiple of 1 MB (default: 1 MB)
block-size: int (optional): Block size in bytes, must be a multiple of 1 MB and not larger than 256 MB (default: automatically choose a block size depending on the image size)
subformat: BlockdevVhdxSubformat (optional): vhdx subformat (default: dynamic)
block-state-zero: boolean (optional): Force use of payload blocks of type ‘ZERO’. Non-standard, but default. Do not set to ‘off’ when using ‘qemu-img convert’ with subformat=dynamic.

Since¶

2.12

`BlockdevVpcSubformat` (Enum)¶

Values¶

dynamic: Growing image file
fixed: Preallocated fixed-size image file

Since¶

2.12

`BlockdevCreateOptionsVpc` (Object)¶

Driver specific image creation options for vpc (VHD).

Members¶

file: BlockdevRef: Node to create the image format on
size: int: Size of the virtual disk in bytes
subformat: BlockdevVpcSubformat (optional): vhdx subformat (default: dynamic)
force-size: boolean (optional): Force use of the exact byte size instead of rounding to the next size that can be represented in CHS geometry (default: false)

Since¶

2.12

`BlockdevCreateOptions` (Object)¶

Options for creating an image format on a given node.

Members¶

driver: BlockdevDriver: block driver to create the image format
The members of BlockdevCreateOptionsFile when driver is "file"
The members of BlockdevCreateOptionsGluster when driver is "gluster"
The members of BlockdevCreateOptionsLUKS when driver is "luks"
The members of BlockdevCreateOptionsNfs when driver is "nfs"
The members of BlockdevCreateOptionsParallels when driver is "parallels"
The members of BlockdevCreateOptionsQcow when driver is "qcow"
The members of BlockdevCreateOptionsQcow2 when driver is "qcow2"
The members of BlockdevCreateOptionsQed when driver is "qed"
The members of BlockdevCreateOptionsRbd when driver is "rbd"
The members of BlockdevCreateOptionsSsh when driver is "ssh"
The members of BlockdevCreateOptionsVdi when driver is "vdi"
The members of BlockdevCreateOptionsVhdx when driver is "vhdx"
The members of BlockdevCreateOptionsVmdk when driver is "vmdk"
The members of BlockdevCreateOptionsVpc when driver is "vpc"

Since¶

2.12

`blockdev-create` (Command)¶

Starts a job to create an image format on a given node. The job is automatically finalized, but a manual job-dismiss is required.

Arguments¶

job-id: string: Identifier for the newly created job.
options: BlockdevCreateOptions: Options for the image creation.

Since¶

3.0

`BlockdevAmendOptionsLUKS` (Object)¶

Driver specific image amend options for LUKS.

Members¶

The members of QCryptoBlockAmendOptionsLUKS

Since¶

5.1

`BlockdevAmendOptionsQcow2` (Object)¶

Driver specific image amend options for qcow2. For now, only encryption options can be amended

encrypt Encryption options to be amended

Members¶

encrypt: QCryptoBlockAmendOptions (optional): Not documented

Since¶

5.1

`BlockdevAmendOptions` (Object)¶

Options for amending an image format

Members¶

driver: BlockdevDriver: Block driver of the node to amend.
The members of BlockdevAmendOptionsLUKS when driver is "luks"
The members of BlockdevAmendOptionsQcow2 when driver is "qcow2"

Since¶

5.1

`x-blockdev-amend` (Command)¶

Starts a job to amend format specific options of an existing open block device The job is automatically finalized, but a manual job-dismiss is required.

Arguments¶

job-id: string: Identifier for the newly created job.
node-name: string: Name of the block node to work on
options: BlockdevAmendOptions: Options (driver specific)
force: boolean (optional): Allow unsafe operations, format specific For luks that allows erase of the last active keyslot (permanent loss of data), and replacement of an active keyslot (possible loss of data if IO error happens)

Since¶

5.1

`BlockErrorAction` (Enum)¶

An enumeration of action that has been taken when a DISK I/O occurs

Values¶

ignore: error has been ignored
report: error has been reported to the device
stop: error caused VM to be stopped

Since¶

2.1

`BLOCK_IMAGE_CORRUPTED` (Event)¶

Emitted when a disk image is being marked corrupt. The image can be identified by its device or node name. The ‘device’ field is always present for compatibility reasons, but it can be empty (“”) if the image does not have a device name associated.

Arguments¶

device: string: device name. This is always present for compatibility reasons, but it can be empty (“”) if the image does not have a device name associated.
node-name: string (optional): node name (Since: 2.4)
msg: string: informative message for human consumption, such as the kind of corruption being detected. It should not be parsed by machine as it is not guaranteed to be stable
offset: int (optional): if the corruption resulted from an image access, this is the host’s access offset into the image
size: int (optional): if the corruption resulted from an image access, this is the access size
fatal: boolean: if set, the image is marked corrupt and therefore unusable after this event and must be repaired (Since 2.2; before, every BLOCK_IMAGE_CORRUPTED event was fatal)

Note¶

If action is “stop”, a STOP event will eventually follow the BLOCK_IO_ERROR event.

Example¶

<- { "event": "BLOCK_IMAGE_CORRUPTED",
     "data": { "device": "ide0-hd0", "node-name": "node0",
               "msg": "Prevented active L1 table overwrite", "offset": 196608,
               "size": 65536 },
     "timestamp": { "seconds": 1378126126, "microseconds": 966463 } }

Since¶

1.7

`BLOCK_IO_ERROR` (Event)¶

Emitted when a disk I/O error occurs

Arguments¶

device: string: device name. This is always present for compatibility reasons, but it can be empty (“”) if the image does not have a device name associated.
node-name: string (optional): node name. Note that errors may be reported for the root node that is directly attached to a guest device rather than for the node where the error occurred. The node name is not present if the drive is empty. (Since: 2.8)
operation: IoOperationType: I/O operation
action: BlockErrorAction: action that has been taken
nospace: boolean (optional): true if I/O error was caused due to a no-space condition. This key is only present if query-block’s io-status is present, please see query-block documentation for more information (since: 2.2)
reason: string: human readable string describing the error cause. (This field is a debugging aid for humans, it should not be parsed by applications) (since: 2.2)

Note¶

If action is “stop”, a STOP event will eventually follow the BLOCK_IO_ERROR event

Since¶

0.13

Example¶

<- { "event": "BLOCK_IO_ERROR",
     "data": { "device": "ide0-hd1",
               "node-name": "#block212",
               "operation": "write",
               "action": "stop" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

`BLOCK_JOB_COMPLETED` (Event)¶

Emitted when a block job has completed

Arguments¶

type: JobType: job type
device: string: The job identifier. Originally the device name but other values are allowed since QEMU 2.7
len: int: maximum progress value
offset: int: current progress value. On success this is equal to len. On failure this is less than len
speed: int: rate limit, bytes per second
error: string (optional): error message. Only present on failure. This field contains a human-readable error message. There are no semantics other than that streaming has failed and clients should not try to interpret the error string

Since¶

1.1

Example¶

<- { "event": "BLOCK_JOB_COMPLETED",
     "data": { "type": "stream", "device": "virtio-disk0",
               "len": 10737418240, "offset": 10737418240,
               "speed": 0 },
     "timestamp": { "seconds": 1267061043, "microseconds": 959568 } }

`BLOCK_JOB_CANCELLED` (Event)¶

Emitted when a block job has been cancelled

Arguments¶

type: JobType: job type
device: string: The job identifier. Originally the device name but other values are allowed since QEMU 2.7
len: int: maximum progress value
offset: int: current progress value. On success this is equal to len. On failure this is less than len
speed: int: rate limit, bytes per second

Since¶

1.1

Example¶

<- { "event": "BLOCK_JOB_CANCELLED",
     "data": { "type": "stream", "device": "virtio-disk0",
               "len": 10737418240, "offset": 134217728,
               "speed": 0 },
     "timestamp": { "seconds": 1267061043, "microseconds": 959568 } }

`BLOCK_JOB_ERROR` (Event)¶

Emitted when a block job encounters an error

Arguments¶

device: string: The job identifier. Originally the device name but other values are allowed since QEMU 2.7
operation: IoOperationType: I/O operation
action: BlockErrorAction: action that has been taken

Since¶

1.3

Example¶

<- { "event": "BLOCK_JOB_ERROR",
     "data": { "device": "ide0-hd1",
               "operation": "write",
               "action": "stop" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

`BLOCK_JOB_READY` (Event)¶

Emitted when a block job is ready to complete

Arguments¶

type: JobType: job type
device: string: The job identifier. Originally the device name but other values are allowed since QEMU 2.7
len: int: maximum progress value
offset: int: current progress value. On success this is equal to len. On failure this is less than len
speed: int: rate limit, bytes per second

Note¶

The “ready to complete” status is always reset by a BLOCK_JOB_ERROR event

Since¶

1.3

Example¶

<- { "event": "BLOCK_JOB_READY",
     "data": { "device": "drive0", "type": "mirror", "speed": 0,
               "len": 2097152, "offset": 2097152 }
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

`BLOCK_JOB_PENDING` (Event)¶

Emitted when a block job is awaiting explicit authorization to finalize graph changes via block-job-finalize. If this job is part of a transaction, it will not emit this event until the transaction has converged first.

Arguments¶

type: JobType: job type
id: string: The job identifier.

Since¶

2.12

Example¶

<- { "event": "BLOCK_JOB_WAITING",
     "data": { "device": "drive0", "type": "mirror" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

`PreallocMode` (Enum)¶

Preallocation mode of QEMU image file

Values¶

off: no preallocation
metadata: preallocate only for metadata
falloc: like full preallocation but allocate disk space by posix_fallocate() rather than writing data.
full: preallocate all data by writing it to the device to ensure disk space is really available. This data may or may not be zero, depending on the image format and storage. full preallocation also sets up metadata correctly.

Since¶

2.2

`BLOCK_WRITE_THRESHOLD` (Event)¶

Emitted when writes on block device reaches or exceeds the configured write threshold. For thin-provisioned devices, this means the device should be extended to avoid pausing for disk exhaustion. The event is one shot. Once triggered, it needs to be re-registered with another block-set-write-threshold command.

Arguments¶

node-name: string: graph node name on which the threshold was exceeded.
amount-exceeded: int: amount of data which exceeded the threshold, in bytes.
write-threshold: int: last configured threshold, in bytes.

Since¶

2.3

`block-set-write-threshold` (Command)¶

Change the write threshold for a block drive. An event will be delivered if a write to this block drive crosses the configured threshold. The threshold is an offset, thus must be non-negative. Default is no write threshold. Setting the threshold to zero disables it.

This is useful to transparently resize thin-provisioned drives without the guest OS noticing.

Arguments¶

node-name: string: graph node name on which the threshold must be set.
write-threshold: int: configured threshold for the block device, bytes. Use 0 to disable the threshold.

Since¶

2.3

Example¶

-> { "execute": "block-set-write-threshold",
     "arguments": { "node-name": "mydev",
                    "write-threshold": 17179869184 } }
<- { "return": {} }

`x-blockdev-change` (Command)¶

Dynamically reconfigure the block driver state graph. It can be used to add, remove, insert or replace a graph node. Currently only the Quorum driver implements this feature to add or remove its child. This is useful to fix a broken quorum child.

If node is specified, it will be inserted under parent. child may not be specified in this case. If both parent and child are specified but node is not, child will be detached from parent.

Arguments¶

parent: string: the id or name of the parent node.
child: string (optional): the name of a child under the given parent node.
node: string (optional): the name of the node that will be added.

Note¶

this command is experimental, and its API is not stable. It does not support all kinds of operations, all kinds of children, nor all block drivers.

FIXME Removing children from a quorum node means introducing gaps in the child indices. This cannot be represented in the ‘children’ list of BlockdevOptionsQuorum, as returned by .bdrv_refresh_filename().

Warning: The data in a new quorum child MUST be consistent with that of the rest of the array.

Since¶

2.7

Example¶

1. Add a new node to a quorum
-> { "execute": "blockdev-add",
     "arguments": {
         "driver": "raw",
         "node-name": "new_node",
         "file": { "driver": "file",
                   "filename": "test.raw" } } }
<- { "return": {} }
-> { "execute": "x-blockdev-change",
     "arguments": { "parent": "disk1",
                    "node": "new_node" } }
<- { "return": {} }

2. Delete a quorum's node
-> { "execute": "x-blockdev-change",
     "arguments": { "parent": "disk1",
                    "child": "children.1" } }
<- { "return": {} }

`x-blockdev-set-iothread` (Command)¶

Move node and its children into the iothread. If iothread is null then move node and its children into the main loop.

The node must not be attached to a BlockBackend.

Arguments¶

node-name: string: the name of the block driver node
iothread: StrOrNull: the name of the IOThread object or null for the main loop
force: boolean (optional): true if the node and its children should be moved when a BlockBackend is already attached

Note¶

this command is experimental and intended for test cases that need control over IOThreads only.

Since¶

2.12

Example¶

1. Move a node into an IOThread
-> { "execute": "x-blockdev-set-iothread",
     "arguments": { "node-name": "disk1",
                    "iothread": "iothread0" } }
<- { "return": {} }

2. Move a node into the main loop
-> { "execute": "x-blockdev-set-iothread",
     "arguments": { "node-name": "disk1",
                    "iothread": null } }
<- { "return": {} }

`QuorumOpType` (Enum)¶

An enumeration of the quorum operation types

Values¶

read: read operation
write: write operation
flush: flush operation

Since¶

2.6

`QUORUM_FAILURE` (Event)¶

Emitted by the Quorum block driver if it fails to establish a quorum

Arguments¶

reference: string: device name if defined else node name
sector-num: int: number of the first sector of the failed read operation
sectors-count: int: failed read operation sector count

Note¶

This event is rate-limited.

Since¶

2.0

Example¶

<- { "event": "QUORUM_FAILURE",
     "data": { "reference": "usr1", "sector-num": 345435, "sectors-count": 5 },
     "timestamp": { "seconds": 1344522075, "microseconds": 745528 } }

`QUORUM_REPORT_BAD` (Event)¶

Emitted to report a corruption of a Quorum file

Arguments¶

type: QuorumOpType: quorum operation type (Since 2.6)
error: string (optional): error message. Only present on failure. This field contains a human-readable error message. There are no semantics other than that the block layer reported an error and clients should not try to interpret the error string.
node-name: string: the graph node name of the block driver state
sector-num: int: number of the first sector of the failed read operation
sectors-count: int: failed read operation sector count

Note¶

This event is rate-limited.

Since¶

2.0

Example¶

1. Read operation

{ "event": "QUORUM_REPORT_BAD",
     "data": { "node-name": "node0", "sector-num": 345435, "sectors-count": 5,
               "type": "read" },
     "timestamp": { "seconds": 1344522075, "microseconds": 745528 } }

2. Flush operation

{ "event": "QUORUM_REPORT_BAD",
     "data": { "node-name": "node0", "sector-num": 0, "sectors-count": 2097120,
               "type": "flush", "error": "Broken pipe" },
     "timestamp": { "seconds": 1456406829, "microseconds": 291763 } }

`BlockdevSnapshotInternal` (Object)¶

Members¶

device: string: the device name or node-name of a root node to generate the snapshot from
name: string: the name of the internal snapshot to be created

Notes¶

In transaction, if name is empty, or any snapshot matching name exists, the operation will fail. Only some image formats support it, for example, qcow2, and rbd.

Since¶

1.7

`blockdev-snapshot-internal-sync` (Command)¶

Synchronously take an internal snapshot of a block device, when the format of the image used supports it. If the name is an empty string, or a snapshot with name already exists, the operation will fail.

For the arguments, see the documentation of BlockdevSnapshotInternal.

Returns¶

nothing on success
If device is not a valid block device, GenericError
If any snapshot matching name exists, or name is empty, GenericError
If the format of the image used does not support it, BlockFormatFeatureNotSupported

Since¶

1.7

Example¶

-> { "execute": "blockdev-snapshot-internal-sync",
     "arguments": { "device": "ide-hd0",
                    "name": "snapshot0" }
   }
<- { "return": {} }

`blockdev-snapshot-delete-internal-sync` (Command)¶

Synchronously delete an internal snapshot of a block device, when the format of the image used support it. The snapshot is identified by name or id or both. One of the name or id is required. Return SnapshotInfo for the successfully deleted snapshot.

Arguments¶

device: string: the device name or node-name of a root node to delete the snapshot from
id: string (optional): optional the snapshot’s ID to be deleted
name: string (optional): optional the snapshot’s name to be deleted

Returns¶

SnapshotInfo on success
If device is not a valid block device, GenericError
If snapshot not found, GenericError
If the format of the image used does not support it, BlockFormatFeatureNotSupported
If id and name are both not specified, GenericError

Since¶

1.7

Example¶

-> { "execute": "blockdev-snapshot-delete-internal-sync",
     "arguments": { "device": "ide-hd0",
                    "name": "snapshot0" }
   }
<- { "return": {
                   "id": "1",
                   "name": "snapshot0",
                   "vm-state-size": 0,
                   "date-sec": 1000012,
                   "date-nsec": 10,
                   "vm-clock-sec": 100,
                   "vm-clock-nsec": 20,
                   "icount": 220414
     }
   }

Additional block stuff (VM related)¶

`BiosAtaTranslation` (Enum)¶

Policy that BIOS should use to interpret cylinder/head/sector addresses. Note that Bochs BIOS and SeaBIOS will not actually translate logical CHS to physical; instead, they will use logical block addressing.

Values¶

auto: If cylinder/heads/sizes are passed, choose between none and LBA depending on the size of the disk. If they are not passed, choose none if QEMU can guess that the disk had 16 or fewer heads, large if QEMU can guess that the disk had 131072 or fewer tracks across all heads (i.e. cylinders*heads<131072), otherwise LBA.
none: The physical disk geometry is equal to the logical geometry.
lba: Assume 63 sectors per track and one of 16, 32, 64, 128 or 255 heads (if fewer than 255 are enough to cover the whole disk with 1024 cylinders/head). The number of cylinders/head is then computed based on the number of sectors and heads.
large: The number of cylinders per head is scaled down to 1024 by correspondingly scaling up the number of heads.
rechs: Same as large, but first convert a 16-head geometry to 15-head, by proportionally scaling up the number of cylinders/head.

Since¶

2.0

`FloppyDriveType` (Enum)¶

Type of Floppy drive to be emulated by the Floppy Disk Controller.

Values¶

144: 1.44MB 3.5” drive
288: 2.88MB 3.5” drive
120: 1.2MB 5.25” drive
none: No drive connected
auto: Automatically determined by inserted media at boot

Since¶

2.6

`PRManagerInfo` (Object)¶

Information about a persistent reservation manager

Members¶

id: string: the identifier of the persistent reservation manager
connected: boolean: true if the persistent reservation manager is connected to the underlying storage or helper

Since¶

3.0

`query-pr-managers` (Command)¶

Returns a list of information about each persistent reservation manager.

Returns¶

a list of PRManagerInfo for each persistent reservation manager

Since¶

3.0

`eject` (Command)¶

Ejects the medium from a removable drive.

Arguments¶

device: string (optional): Block device name
id: string (optional): The name or QOM path of the guest device (since: 2.8)
force: boolean (optional): If true, eject regardless of whether the drive is locked. If not specified, the default value is false.

Features¶

deprecated: Member device is deprecated. Use id instead.

Returns¶

Nothing on success
If device is not a valid block device, DeviceNotFound

Notes¶

Ejecting a device with no media results in success

Since¶

0.14

Example¶

-> { "execute": "eject", "arguments": { "id": "ide1-0-1" } }
<- { "return": {} }

`blockdev-open-tray` (Command)¶

Opens a block device’s tray. If there is a block driver state tree inserted as a medium, it will become inaccessible to the guest (but it will remain associated to the block device, so closing the tray will make it accessible again).

If the tray was already open before, this will be a no-op.

Once the tray opens, a DEVICE_TRAY_MOVED event is emitted. There are cases in which no such event will be generated, these include:

if the guest has locked the tray, force is false and the guest does not respond to the eject request
if the BlockBackend denoted by device does not have a guest device attached to it
if the guest device does not have an actual tray

Arguments¶

device: string (optional): Block device name
id: string (optional): The name or QOM path of the guest device (since: 2.8)
force: boolean (optional): if false (the default), an eject request will be sent to the guest if it has locked the tray (and the tray will not be opened immediately); if true, the tray will be opened regardless of whether it is locked

Features¶

deprecated: Member device is deprecated. Use id instead.

Since¶

2.5

Example¶

-> { "execute": "blockdev-open-tray",
     "arguments": { "id": "ide0-1-0" } }

<- { "timestamp": { "seconds": 1418751016,
                    "microseconds": 716996 },
     "event": "DEVICE_TRAY_MOVED",
     "data": { "device": "ide1-cd0",
               "id": "ide0-1-0",
               "tray-open": true } }

<- { "return": {} }

`blockdev-close-tray` (Command)¶

Closes a block device’s tray. If there is a block driver state tree associated with the block device (which is currently ejected), that tree will be loaded as the medium.

If the tray was already closed before, this will be a no-op.

Arguments¶

device: string (optional): Block device name
id: string (optional): The name or QOM path of the guest device (since: 2.8)

Features¶

deprecated: Member device is deprecated. Use id instead.

Since¶

2.5

Example¶

-> { "execute": "blockdev-close-tray",
     "arguments": { "id": "ide0-1-0" } }

<- { "timestamp": { "seconds": 1418751345,
                    "microseconds": 272147 },
     "event": "DEVICE_TRAY_MOVED",
     "data": { "device": "ide1-cd0",
               "id": "ide0-1-0",
               "tray-open": false } }

<- { "return": {} }

`blockdev-remove-medium` (Command)¶

Removes a medium (a block driver state tree) from a block device. That block device’s tray must currently be open (unless there is no attached guest device).

If the tray is open and there is no medium inserted, this will be a no-op.

Arguments¶

id: string: The name or QOM path of the guest device

Since¶

2.12

Example¶

-> { "execute": "blockdev-remove-medium",
     "arguments": { "id": "ide0-1-0" } }

<- { "error": { "class": "GenericError",
                "desc": "Tray of device 'ide0-1-0' is not open" } }

-> { "execute": "blockdev-open-tray",
     "arguments": { "id": "ide0-1-0" } }

<- { "timestamp": { "seconds": 1418751627,
                    "microseconds": 549958 },
     "event": "DEVICE_TRAY_MOVED",
     "data": { "device": "ide1-cd0",
               "id": "ide0-1-0",
               "tray-open": true } }

<- { "return": {} }

-> { "execute": "blockdev-remove-medium",
     "arguments": { "id": "ide0-1-0" } }

<- { "return": {} }

`blockdev-insert-medium` (Command)¶

Inserts a medium (a block driver state tree) into a block device. That block device’s tray must currently be open (unless there is no attached guest device) and there must be no medium inserted already.

Arguments¶

id: string: The name or QOM path of the guest device
node-name: string: name of a node in the block driver state graph

Since¶

2.12

Example¶

-> { "execute": "blockdev-add",
     "arguments": {
         "node-name": "node0",
         "driver": "raw",
         "file": { "driver": "file",
                   "filename": "fedora.iso" } } }
<- { "return": {} }

-> { "execute": "blockdev-insert-medium",
     "arguments": { "id": "ide0-1-0",
                    "node-name": "node0" } }

<- { "return": {} }

`BlockdevChangeReadOnlyMode` (Enum)¶

Specifies the new read-only mode of a block device subject to the blockdev-change-medium command.

Values¶

retain: Retains the current read-only mode
read-only: Makes the device read-only
read-write: Makes the device writable

Since¶

2.3

`blockdev-change-medium` (Command)¶

Changes the medium inserted into a block device by ejecting the current medium and loading a new image file which is inserted as the new medium (this command combines blockdev-open-tray, blockdev-remove-medium, blockdev-insert-medium and blockdev-close-tray).

Arguments¶

device: string (optional): Block device name
id: string (optional): The name or QOM path of the guest device (since: 2.8)
filename: string: filename of the new image to be loaded
format: string (optional): format to open the new image with (defaults to the probed format)
read-only-mode: BlockdevChangeReadOnlyMode (optional): change the read-only mode of the device; defaults to ‘retain’

Features¶

deprecated: Member device is deprecated. Use id instead.

Since¶

2.5

Examples¶

1. Change a removable medium

-> { "execute": "blockdev-change-medium",
     "arguments": { "id": "ide0-1-0",
                    "filename": "/srv/images/Fedora-12-x86_64-DVD.iso",
                    "format": "raw" } }
<- { "return": {} }

2. Load a read-only medium into a writable drive

-> { "execute": "blockdev-change-medium",
     "arguments": { "id": "floppyA",
                    "filename": "/srv/images/ro.img",
                    "format": "raw",
                    "read-only-mode": "retain" } }

<- { "error":
     { "class": "GenericError",
       "desc": "Could not open '/srv/images/ro.img': Permission denied" } }

-> { "execute": "blockdev-change-medium",
     "arguments": { "id": "floppyA",
                    "filename": "/srv/images/ro.img",
                    "format": "raw",
                    "read-only-mode": "read-only" } }

<- { "return": {} }

`DEVICE_TRAY_MOVED` (Event)¶

Emitted whenever the tray of a removable device is moved by the guest or by HMP/QMP commands

Arguments¶

device: string: Block device name. This is always present for compatibility reasons, but it can be empty (“”) if the image does not have a device name associated.
id: string: The name or QOM path of the guest device (since 2.8)
tray-open: boolean: true if the tray has been opened or false if it has been closed

Since¶

1.1

Example¶

<- { "event": "DEVICE_TRAY_MOVED",
     "data": { "device": "ide1-cd0",
               "id": "/machine/unattached/device[22]",
               "tray-open": true
     },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

`PR_MANAGER_STATUS_CHANGED` (Event)¶

Emitted whenever the connected status of a persistent reservation manager changes.

Arguments¶

id: string: The id of the PR manager object
connected: boolean: true if the PR manager is connected to a backend

Since¶

3.0

Example¶

<- { "event": "PR_MANAGER_STATUS_CHANGED",
     "data": { "id": "pr-helper0",
               "connected": true
     },
     "timestamp": { "seconds": 1519840375, "microseconds": 450486 } }

`block_set_io_throttle` (Command)¶

Change I/O throttle limits for a block drive.

Since QEMU 2.4, each device with I/O limits is member of a throttle group.

If two or more devices are members of the same group, the limits will apply to the combined I/O of the whole group in a round-robin fashion. Therefore, setting new I/O limits to a device will affect the whole group.

The name of the group can be specified using the ‘group’ parameter. If the parameter is unset, it is assumed to be the current group of that device. If it’s not in any group yet, the name of the device will be used as the name for its group.

The ‘group’ parameter can also be used to move a device to a different group. In this case the limits specified in the parameters will be applied to the new group only.

I/O limits can be disabled by setting all of them to 0. In this case the device will be removed from its group and the rest of its members will not be affected. The ‘group’ parameter is ignored.

Arguments¶

The members of BlockIOThrottle

Returns¶

Nothing on success
If device is not a valid block device, DeviceNotFound

Since¶

1.1

Example¶

-> { "execute": "block_set_io_throttle",
     "arguments": { "id": "virtio-blk-pci0/virtio-backend",
                    "bps": 0,
                    "bps_rd": 0,
                    "bps_wr": 0,
                    "iops": 512,
                    "iops_rd": 0,
                    "iops_wr": 0,
                    "bps_max": 0,
                    "bps_rd_max": 0,
                    "bps_wr_max": 0,
                    "iops_max": 0,
                    "iops_rd_max": 0,
                    "iops_wr_max": 0,
                    "bps_max_length": 0,
                    "iops_size": 0 } }
<- { "return": {} }

-> { "execute": "block_set_io_throttle",
     "arguments": { "id": "ide0-1-0",
                    "bps": 1000000,
                    "bps_rd": 0,
                    "bps_wr": 0,
                    "iops": 0,
                    "iops_rd": 0,
                    "iops_wr": 0,
                    "bps_max": 8000000,
                    "bps_rd_max": 0,
                    "bps_wr_max": 0,
                    "iops_max": 0,
                    "iops_rd_max": 0,
                    "iops_wr_max": 0,
                    "bps_max_length": 60,
                    "iops_size": 0 } }
<- { "return": {} }

`block-latency-histogram-set` (Command)¶

Manage read, write and flush latency histograms for the device.

If only id parameter is specified, remove all present latency histograms for the device. Otherwise, add/reset some of (or all) latency histograms.

Arguments¶

id: string: The name or QOM path of the guest device.
boundaries: array of int (optional): list of interval boundary values (see description in BlockLatencyHistogramInfo definition). If specified, all latency histograms are removed, and empty ones created for all io types with intervals corresponding to boundaries (except for io types, for which specific boundaries are set through the following parameters).
boundaries-read: array of int (optional): list of interval boundary values for read latency histogram. If specified, old read latency histogram is removed, and empty one created with intervals corresponding to boundaries-read. The parameter has higher priority then boundaries.
boundaries-write: array of int (optional): list of interval boundary values for write latency histogram.
boundaries-flush: array of int (optional): list of interval boundary values for flush latency histogram.

Returns¶

error if device is not found or any boundary arrays are invalid.

Since¶

4.0

Example¶

set new histograms for all io types with intervals
[0, 10), [10, 50), [50, 100), [100, +inf):

-> { "execute": "block-latency-histogram-set",
     "arguments": { "id": "drive0",
                    "boundaries": [10, 50, 100] } }
<- { "return": {} }

Example¶

set new histogram only for write, other histograms will remain
not changed (or not created):

-> { "execute": "block-latency-histogram-set",
     "arguments": { "id": "drive0",
                    "boundaries-write": [10, 50, 100] } }
<- { "return": {} }

Example¶

set new histograms with the following intervals:
  read, flush: [0, 10), [10, 50), [50, 100), [100, +inf)
  write: [0, 1000), [1000, 5000), [5000, +inf)

-> { "execute": "block-latency-histogram-set",
     "arguments": { "id": "drive0",
                    "boundaries": [10, 50, 100],
                    "boundaries-write": [1000, 5000] } }
<- { "return": {} }

Example¶

remove all latency histograms:

-> { "execute": "block-latency-histogram-set",
     "arguments": { "id": "drive0" } }
<- { "return": {} }

Block device exports¶

`NbdServerOptions` (Object)¶

Keep this type consistent with the nbd-server-start arguments. The only intended difference is using SocketAddress instead of SocketAddressLegacy.

Members¶

addr: SocketAddress: Address on which to listen.
tls-creds: string (optional): ID of the TLS credentials object (since 2.6).
tls-authz: string (optional): ID of the QAuthZ authorization object used to validate the client’s x509 distinguished name. This object is is only resolved at time of use, so can be deleted and recreated on the fly while the NBD server is active. If missing, it will default to denying access (since 4.0).
max-connections: int (optional): The maximum number of connections to allow at the same time, 0 for unlimited. (since 5.2; default: 0)

Since¶

4.2

`nbd-server-start` (Command)¶

Start an NBD server listening on the given host and port. Block devices can then be exported using nbd-server-add. The NBD server will present them as named exports; for example, another QEMU instance could refer to them as “nbd:HOST:PORT:exportname=NAME”.

Keep this type consistent with the NbdServerOptions type. The only intended difference is using SocketAddressLegacy instead of SocketAddress.

Arguments¶

addr: SocketAddressLegacy: Address on which to listen.
tls-creds: string (optional): ID of the TLS credentials object (since 2.6).
tls-authz: string (optional): ID of the QAuthZ authorization object used to validate the client’s x509 distinguished name. This object is is only resolved at time of use, so can be deleted and recreated on the fly while the NBD server is active. If missing, it will default to denying access (since 4.0).
max-connections: int (optional): The maximum number of connections to allow at the same time, 0 for unlimited. (since 5.2; default: 0)

`nbd-server-add` (Command)¶

Export a block node to QEMU’s embedded NBD server.

The export name will be used as the id for the resulting block export.

Arguments¶

The members of NbdServerAddOptions

Features¶

deprecated: This command is deprecated. Use block-export-add instead.

Returns¶

error if the server is not running, or export with the same name already exists.

Since¶

1.3

`BlockExportRemoveMode` (Enum)¶

Mode for removing a block export.

Values¶

safe: Remove export if there are no existing connections, fail otherwise.
hard: Drop all connections immediately and remove export.

Potential additional modes to be added in the future:

hide: Just hide export from new clients, leave existing connections as is. Remove export after all clients are disconnected.

soft: Hide export from new clients, answer with ESHUTDOWN for all further requests from existing clients.

Since¶

2.12

`nbd-server-remove` (Command)¶

Remove NBD export by name.

Arguments¶

name: string: Block export id.
mode: BlockExportRemoveMode (optional): Mode of command operation. See BlockExportRemoveMode description. Default is ‘safe’.

Features¶

deprecated: This command is deprecated. Use block-export-del instead.

Returns¶

error if

the server is not running
export is not found
mode is ‘safe’ and there are existing connections

Since¶

5.2

`query-block-exports` (Command)¶

Returns¶

A list of BlockExportInfo describing all block exports

Since¶

5.2

Character devices¶

`ChardevInfo` (Object)¶

Information about a character device.

Members¶

label: string: the label of the character device
filename: string: the filename of the character device
frontend-open: boolean: shows whether the frontend device attached to this backend (eg. with the chardev=… option) is in open or closed state (since 2.1)

Example¶

-> { "execute": "query-chardev-backends" }
<- {
      "return":[
         {
            "name":"udp"
         },
         {
            "name":"tcp"
         },
         {
            "name":"unix"
         },
         {
            "name":"spiceport"
         }
      ]
   }

`DataFormat` (Enum)¶

An enumeration of data format.

Values¶

utf8: Data is a UTF-8 string (RFC 3629)
base64: Data is Base64 encoded binary (RFC 3548)

Since¶

1.4

`ringbuf-write` (Command)¶

Write to a ring buffer character device.

Arguments¶

device: string

the ring buffer character device name

data: string

data to write

format: DataFormat (optional)

data encoding (default ‘utf8’).

base64: data must be base64 encoded text. Its binary decoding gets written.
utf8: data’s UTF-8 encoding is written
data itself is always Unicode regardless of format, like any other string.

Returns¶

Nothing on success

Since¶

1.4

Example¶

-> { "execute": "ringbuf-write",
     "arguments": { "device": "foo",
                    "data": "abcdefgh",
                    "format": "utf8" } }
<- { "return": {} }

`ringbuf-read` (Command)¶

Read from a ring buffer character device.

Arguments¶

device: string

the ring buffer character device name

size: int

how many bytes to read at most

format: DataFormat (optional)

data encoding (default ‘utf8’).

base64: the data read is returned in base64 encoding.
utf8: the data read is interpreted as UTF-8. Bug: can screw up when the buffer contains invalid UTF-8 sequences, NUL characters, after the ring buffer lost data, and when reading stops because the size limit is reached.
The return value is always Unicode regardless of format, like any other string.

Returns¶

data read from the device

Since¶

1.4

Example¶

-> { "execute": "ringbuf-read",
     "arguments": { "device": "foo",
                    "size": 1000,
                    "format": "utf8" } }
<- { "return": "abcdefgh" }

`ChardevCommon` (Object)¶

Configuration shared across all chardev backends

Members¶

logfile: string (optional): The name of a logfile to save output
logappend: boolean (optional): true to append instead of truncate (default to false to truncate)

Since¶

2.6

`ChardevFile` (Object)¶

Configuration info for file chardevs.

Members¶

in: string (optional): The name of the input file
out: string: The name of the output file
append: boolean (optional): Open the file in append mode (default false to truncate) (Since 2.6)
The members of ChardevCommon

Since¶

1.4

`ChardevHostdev` (Object)¶

Configuration info for device and pipe chardevs.

Members¶

device: string: The name of the special file for the device, i.e. /dev/ttyS0 on Unix or COM1: on Windows
The members of ChardevCommon

Since¶

1.4

`ChardevSocket` (Object)¶

Configuration info for (stream) socket chardevs.

Members¶

addr: SocketAddressLegacy: socket address to listen on (server=true) or connect to (server=false)
tls-creds: string (optional): the ID of the TLS credentials object (since 2.6)
tls-authz: string (optional): the ID of the QAuthZ authorization object against which the client’s x509 distinguished name will be validated. This object is only resolved at time of use, so can be deleted and recreated on the fly while the chardev server is active. If missing, it will default to denying access (since 4.0)
server: boolean (optional): create server socket (default: true)
wait: boolean (optional): wait for incoming connection on server sockets (default: false). Silently ignored with server: false. This use is deprecated.
nodelay: boolean (optional): set TCP_NODELAY socket option (default: false)
telnet: boolean (optional): enable telnet protocol on server sockets (default: false)
tn3270: boolean (optional): enable tn3270 protocol on server sockets (default: false) (Since: 2.10)
websocket: boolean (optional): enable websocket protocol on server sockets (default: false) (Since: 3.1)
reconnect: int (optional): For a client socket, if a socket is disconnected, then attempt a reconnect after the given number of seconds. Setting this to zero disables this function. (default: 0) (Since: 2.2)
The members of ChardevCommon

Since¶

1.4

`ChardevUdp` (Object)¶

Configuration info for datagram socket chardevs.

Members¶

remote: SocketAddressLegacy: remote address
local: SocketAddressLegacy (optional): local address
The members of ChardevCommon

Since¶

1.5

`ChardevMux` (Object)¶

Configuration info for mux chardevs.

Members¶

chardev: string: name of the base chardev.
The members of ChardevCommon

Since¶

1.5

`ChardevStdio` (Object)¶

Configuration info for stdio chardevs.

Members¶

signal: boolean (optional): Allow signals (such as SIGINT triggered by ^C) be delivered to qemu. Default: true.
The members of ChardevCommon

Since¶

1.5

`ChardevSpiceChannel` (Object)¶

Configuration info for spice vm channel chardevs.

Members¶

type: string: kind of channel (for example vdagent).
The members of ChardevCommon

Since¶

1.5

If¶

defined(CONFIG_SPICE)

`ChardevSpicePort` (Object)¶

Configuration info for spice port chardevs.

Members¶

fqdn: string: name of the channel (see docs/spice-port-fqdn.txt)
The members of ChardevCommon

Since¶

1.5

If¶

defined(CONFIG_SPICE)

`ChardevVC` (Object)¶

Configuration info for virtual console chardevs.

Members¶

width: int (optional): console width, in pixels
height: int (optional): console height, in pixels
cols: int (optional): console width, in chars
rows: int (optional): console height, in chars
The members of ChardevCommon

Since¶

1.5

`ChardevRingbuf` (Object)¶

Configuration info for ring buffer chardevs.

Members¶

size: int (optional): ring buffer size, must be power of two, default is 65536
The members of ChardevCommon

Since¶

1.5

`ChardevBackend` (Object)¶

Configuration info for the new chardev backend.

Members¶

type: One of file, serial, parallel, pipe, socket, udp, pty, null, mux, msmouse, wctablet, braille, testdev, stdio, console, spicevmc, spiceport, vc, ringbuf, memory
data: ChardevFile when type is "file"
data: ChardevHostdev when type is "serial"
data: ChardevHostdev when type is "parallel"
data: ChardevHostdev when type is "pipe"
data: ChardevSocket when type is "socket"
data: ChardevUdp when type is "udp"
data: ChardevCommon when type is "pty"
data: ChardevCommon when type is "null"
data: ChardevMux when type is "mux"
data: ChardevCommon when type is "msmouse"
data: ChardevCommon when type is "wctablet"
data: ChardevCommon when type is "braille"
data: ChardevCommon when type is "testdev"
data: ChardevStdio when type is "stdio"
data: ChardevCommon when type is "console"
data: ChardevSpiceChannel when type is "spicevmc" (If: defined(CONFIG_SPICE))
data: ChardevSpicePort when type is "spiceport" (If: defined(CONFIG_SPICE))
data: ChardevVC when type is "vc"
data: ChardevRingbuf when type is "ringbuf"
data: ChardevRingbuf when type is "memory"

Since¶

1.4 (testdev since 2.2, wctablet since 2.9)

`ChardevReturn` (Object)¶

Return info about the chardev backend just created.

Members¶

pty: string (optional): name of the slave pseudoterminal device, present if and only if a chardev of type ‘pty’ was created

Since¶

1.4

`chardev-add` (Command)¶

Add a character device backend

Arguments¶

id: string: the chardev’s ID, must be unique
backend: ChardevBackend: backend type and parameters

Returns¶

ChardevReturn.

Since¶

1.4

Example¶

-> { "execute" : "chardev-add",
     "arguments" : { "id" : "foo",
                     "backend" : { "type" : "null", "data" : {} } } }
<- { "return": {} }

-> { "execute" : "chardev-add",
     "arguments" : { "id" : "bar",
                     "backend" : { "type" : "file",
                                   "data" : { "out" : "/tmp/bar.log" } } } }
<- { "return": {} }

-> { "execute" : "chardev-add",
     "arguments" : { "id" : "baz",
                     "backend" : { "type" : "pty", "data" : {} } } }
<- { "return": { "pty" : "/dev/pty/42" } }

`chardev-change` (Command)¶

Change a character device backend

Arguments¶

id: string: the chardev’s ID, must exist
backend: ChardevBackend: new backend type and parameters

Returns¶

ChardevReturn.

Since¶

2.10

Example¶

-> { "execute" : "chardev-change",
     "arguments" : { "id" : "baz",
                     "backend" : { "type" : "pty", "data" : {} } } }
<- { "return": { "pty" : "/dev/pty/42" } }

-> {"execute" : "chardev-change",
    "arguments" : {
        "id" : "charchannel2",
        "backend" : {
            "type" : "socket",
            "data" : {
                "addr" : {
                    "type" : "unix" ,
                    "data" : {
                        "path" : "/tmp/charchannel2.socket"
                    }
                 },
                 "server" : true,
                 "wait" : false }}}}
<- {"return": {}}

`chardev-remove` (Command)¶

Remove a character device backend

Arguments¶

id: string: the chardev’s ID, must exist and not be in use

Returns¶

Nothing on success

Since¶

1.4

Example¶

-> { "execute": "chardev-remove", "arguments": { "id" : "foo" } }
<- { "return": {} }

`chardev-send-break` (Command)¶

Send a break to a character device

Arguments¶

id: string: the chardev’s ID, must exist

Returns¶

Nothing on success

Since¶

2.10

Example¶

-> { "execute": "chardev-send-break", "arguments": { "id" : "foo" } }
<- { "return": {} }

`VSERPORT_CHANGE` (Event)¶

Emitted when the guest opens or closes a virtio-serial port.

Arguments¶

id: string: device identifier of the virtio-serial port
open: boolean: true if the guest has opened the virtio-serial port

Note¶

This event is rate-limited.

Since¶

2.1

Example¶

<- { "event": "VSERPORT_CHANGE",
     "data": { "id": "channel0", "open": true },
     "timestamp": { "seconds": 1401385907, "microseconds": 422329 } }

Dump guest memory¶

`DumpGuestMemoryFormat` (Enum)¶

An enumeration of guest-memory-dump’s format.

Values¶

elf: elf format
kdump-zlib: kdump-compressed format with zlib-compressed
kdump-lzo: kdump-compressed format with lzo-compressed
kdump-snappy: kdump-compressed format with snappy-compressed
win-dmp: Windows full crashdump format, can be used instead of ELF converting (since 2.13)

Since¶

2.0

`dump-guest-memory` (Command)¶

Dump guest’s memory to vmcore. It is a synchronous operation that can take very long depending on the amount of guest memory.

Arguments¶

paging: boolean

if true, do paging to get guest’s memory mapping. This allows using gdb to process the core file.

IMPORTANT: this option can make QEMU allocate several gigabytes of RAM. This can happen for a large guest, or a malicious guest pretending to be large.

Also, paging=true has the following limitations:

The guest may be in a catastrophic state or can have corrupted memory, which cannot be trusted

The guest can be in real-mode even if paging is enabled. For example, the guest uses ACPI to sleep, and ACPI sleep state goes in real-mode

Currently only supported on i386 and x86_64.

protocol: string

the filename or file descriptor of the vmcore. The supported protocols are:

file: the protocol starts with “file:”, and the following string is the file’s path.
fd: the protocol starts with “fd:”, and the following string is the fd’s name.

detach: boolean (optional)

if true, QMP will return immediately rather than waiting for the dump to finish. The user can track progress using “query-dump”. (since 2.6).

begin: int (optional)

if specified, the starting physical address.

length: int (optional)

if specified, the memory size, in bytes. If you don’t want to dump all guest’s memory, please specify the start begin and length

format: DumpGuestMemoryFormat (optional)

if specified, the format of guest memory dump. But non-elf format is conflict with paging and filter, ie. paging, begin and length is not allowed to be specified with non-elf format at the same time (since 2.0)

Note¶

All boolean arguments default to false

Returns¶

nothing on success

Since¶

1.2

Example¶

-> { "execute": "dump-guest-memory",
     "arguments": { "protocol": "fd:dump" } }
<- { "return": {} }

`DumpStatus` (Enum)¶

Describe the status of a long-running background guest memory dump.

Values¶

none: no dump-guest-memory has started yet.
active: there is one dump running in background.
completed: the last dump has finished successfully.
failed: the last dump has failed.

Since¶

2.6

`DumpQueryResult` (Object)¶

The result format for ‘query-dump’.

Members¶

status: DumpStatus: enum of DumpStatus, which shows current dump status
completed: int: bytes written in latest dump (uncompressed)
total: int: total bytes to be written in latest dump (uncompressed)

Since¶

2.6

`query-dump` (Command)¶

Query latest dump status.

Returns¶

A DumpStatus object showing the dump status.

Since¶

2.6

Example¶

-> { "execute": "query-dump" }
<- { "return": { "status": "active", "completed": 1024000,
                 "total": 2048000 } }

`DUMP_COMPLETED` (Event)¶

Emitted when background dump has completed

Arguments¶

result: DumpQueryResult: final dump status
error: string (optional): human-readable error string that provides hint on why dump failed. Only presents on failure. The user should not try to interpret the error string.

Since¶

2.6

Example¶

{ "event": "DUMP_COMPLETED",
  "data": {"result": {"total": 1090650112, "status": "completed",
                      "completed": 1090650112} } }

`DumpGuestMemoryCapability` (Object)¶

A list of the available formats for dump-guest-memory

Members¶

formats: array of DumpGuestMemoryFormat: Not documented

Since¶

2.0

`query-dump-guest-memory-capability` (Command)¶

Returns the available formats for dump-guest-memory

Returns¶

A DumpGuestMemoryCapability object listing available formats for dump-guest-memory

Since¶

2.0

Example¶

-> { "execute": "query-dump-guest-memory-capability" }
<- { "return": { "formats":
                 ["elf", "kdump-zlib", "kdump-lzo", "kdump-snappy"] }

Net devices¶

`set_link` (Command)¶

Sets the link status of a virtual network adapter.

Arguments¶

name: string: the device name of the virtual network adapter
up: boolean: true to set the link status to be up

Returns¶

Nothing on success If name is not a valid network device, DeviceNotFound

Since¶

0.14

Notes¶

Not all network adapters support setting link status. This command will succeed even if the network adapter does not support link status notification.

Example¶

-> { "execute": "set_link",
     "arguments": { "name": "e1000.0", "up": false } }
<- { "return": {} }

`netdev_add` (Command)¶

Add a network backend.

Additional arguments depend on the type.

Arguments¶

The members of Netdev

Since¶

0.14

Returns¶

Nothing on success If type is not a valid network backend, DeviceNotFound

Example¶

-> { "execute": "netdev_add",
     "arguments": { "type": "user", "id": "netdev1",
                    "dnssearch": "example.org" } }
<- { "return": {} }

`netdev_del` (Command)¶

Remove a network backend.

Arguments¶

id: string: the name of the network backend to remove

Returns¶

Nothing on success If id is not a valid network backend, DeviceNotFound

Since¶

0.14

Example¶

-> { "execute": "netdev_del", "arguments": { "id": "netdev1" } }
<- { "return": {} }

`NetLegacyNicOptions` (Object)¶

Create a new Network Interface Card.

Members¶

netdev: string (optional): id of -netdev to connect to
macaddr: string (optional): MAC address
model: string (optional): device model (e1000, rtl8139, virtio etc.)
addr: string (optional): PCI device address
vectors: int (optional): number of MSI-x vectors, 0 to disable MSI-X

Since¶

1.2

`NetdevUserOptions` (Object)¶

Use the user mode network stack which requires no administrator privilege to run.

Members¶

hostname: string (optional): client hostname reported by the builtin DHCP server
restrict: boolean (optional): isolate the guest from the host
ipv4: boolean (optional): whether to support IPv4, default true for enabled (since 2.6)
ipv6: boolean (optional): whether to support IPv6, default true for enabled (since 2.6)
ip: string (optional): legacy parameter, use net= instead
net: string (optional): IP network address that the guest will see, in the form addr[/netmask] The netmask is optional, and can be either in the form a.b.c.d or as a number of valid top-most bits. Default is 10.0.2.0/24.
host: string (optional): guest-visible address of the host
tftp: string (optional): root directory of the built-in TFTP server
bootfile: string (optional): BOOTP filename, for use with tftp=
dhcpstart: string (optional): the first of the 16 IPs the built-in DHCP server can assign
dns: string (optional): guest-visible address of the virtual nameserver
dnssearch: array of String (optional): list of DNS suffixes to search, passed as DHCP option to the guest
domainname: string (optional): guest-visible domain name of the virtual nameserver (since 3.0)
ipv6-prefix: string (optional): IPv6 network prefix (default is fec0::) (since 2.6). The network prefix is given in the usual hexadecimal IPv6 address notation.
ipv6-prefixlen: int (optional): IPv6 network prefix length (default is 64) (since 2.6)
ipv6-host: string (optional): guest-visible IPv6 address of the host (since 2.6)
ipv6-dns: string (optional): guest-visible IPv6 address of the virtual nameserver (since 2.6)
smb: string (optional): root directory of the built-in SMB server
smbserver: string (optional): IP address of the built-in SMB server
hostfwd: array of String (optional): redirect incoming TCP or UDP host connections to guest endpoints
guestfwd: array of String (optional): forward guest TCP connections
tftp-server-name: string (optional): RFC2132 “TFTP server name” string (Since 3.1)

Since¶

1.2

`NetdevTapOptions` (Object)¶

Used to configure a host TAP network interface backend.

Members¶

ifname: string (optional): interface name
fd: string (optional): file descriptor of an already opened tap
fds: string (optional): multiple file descriptors of already opened multiqueue capable tap
script: string (optional): script to initialize the interface
downscript: string (optional): script to shut down the interface
br: string (optional): bridge name (since 2.8)
helper: string (optional): command to execute to configure bridge
sndbuf: int (optional): send buffer limit. Understands [TGMKkb] suffixes.
vnet_hdr: boolean (optional): enable the IFF_VNET_HDR flag on the tap interface
vhost: boolean (optional): enable vhost-net network accelerator
vhostfd: string (optional): file descriptor of an already opened vhost net device
vhostfds: string (optional): file descriptors of multiple already opened vhost net devices
vhostforce: boolean (optional): vhost on for non-MSIX virtio guests
queues: int (optional): number of queues to be created for multiqueue capable tap
poll-us: int (optional): maximum number of microseconds that could be spent on busy polling for tap (since 2.7)

Since¶

1.2

`NetdevSocketOptions` (Object)¶

Socket netdevs are used to establish a network connection to another QEMU virtual machine via a TCP socket.

Members¶

fd: string (optional): file descriptor of an already opened socket
listen: string (optional): port number, and optional hostname, to listen on
connect: string (optional): port number, and optional hostname, to connect to
mcast: string (optional): UDP multicast address and port number
localaddr: string (optional): source address and port for multicast and udp packets
udp: string (optional): UDP unicast address and port number

Since¶

1.2

`NetdevL2TPv3Options` (Object)¶

Configure an Ethernet over L2TPv3 tunnel.

Members¶

src: string: source address
dst: string: destination address
srcport: string (optional): source port - mandatory for udp, optional for ip
dstport: string (optional): destination port - mandatory for udp, optional for ip
ipv6: boolean (optional): force the use of ipv6
udp: boolean (optional): use the udp version of l2tpv3 encapsulation
cookie64: boolean (optional): use 64 bit coookies
counter: boolean (optional): have sequence counter
pincounter: boolean (optional): pin sequence counter to zero - workaround for buggy implementations or networks with packet reorder
txcookie: int (optional): 32 or 64 bit transmit cookie
rxcookie: int (optional): 32 or 64 bit receive cookie
txsession: int: 32 bit transmit session
rxsession: int (optional): 32 bit receive session - if not specified set to the same value as transmit
offset: int (optional): additional offset - allows the insertion of additional application-specific data before the packet payload

Since¶

2.1

`NetdevVdeOptions` (Object)¶

Connect to a vde switch running on the host.

Members¶

sock: string (optional): socket path
port: int (optional): port number
group: string (optional): group owner of socket
mode: int (optional): permissions for socket

Since¶

1.2

`NetdevBridgeOptions` (Object)¶

Connect a host TAP network interface to a host bridge device.

Members¶

br: string (optional): bridge name
helper: string (optional): command to execute to configure bridge

Since¶

1.2

`NetdevHubPortOptions` (Object)¶

Connect two or more net clients through a software hub.

Members¶

hubid: int: hub identifier number
netdev: string (optional): used to connect hub to a netdev instead of a device (since 2.12)

Since¶

1.2

`NetdevNetmapOptions` (Object)¶

Connect a client to a netmap-enabled NIC or to a VALE switch port

Members¶

ifname: string: Either the name of an existing network interface supported by netmap, or the name of a VALE port (created on the fly). A VALE port name is in the form ‘valeXXX:YYY’, where XXX and YYY are non-negative integers. XXX identifies a switch and YYY identifies a port of the switch. VALE ports having the same XXX are therefore connected to the same switch.
devname: string (optional): path of the netmap device (default: ‘/dev/netmap’).

Since¶

2.0

`NetdevVhostUserOptions` (Object)¶

Vhost-user network backend

Members¶

chardev: string: name of a unix socket chardev
vhostforce: boolean (optional): vhost on for non-MSIX virtio guests (default: false).
queues: int (optional): number of queues to be created for multiqueue vhost-user (default: 1) (Since 2.5)

Since¶

2.1

`NetdevVhostVDPAOptions` (Object)¶

Vhost-vdpa network backend

vDPA device is a device that uses a datapath which complies with the virtio specifications with a vendor specific control path.

Members¶

vhostdev: string (optional): path of vhost-vdpa device (default:’/dev/vhost-vdpa-0’)
queues: int (optional): number of queues to be created for multiqueue vhost-vdpa (default: 1)

Since¶

5.1

`NetClientDriver` (Enum)¶

Available netdev drivers.

Values¶

none: Not documented
nic: Not documented
user: Not documented
tap: Not documented
l2tpv3: Not documented
socket: Not documented
vde: Not documented
bridge: Not documented
hubport: Not documented
netmap: Not documented
vhost-user: Not documented
vhost-vdpa: Not documented

Since¶

2.7

vhost-vdpa since 5.1

`Netdev` (Object)¶

Captures the configuration of a network device.

Members¶

id: string: identifier for monitor commands.
type: NetClientDriver: Specify the driver used for interpreting remaining arguments.
The members of NetLegacyNicOptions when type is "nic"
The members of NetdevUserOptions when type is "user"
The members of NetdevTapOptions when type is "tap"
The members of NetdevL2TPv3Options when type is "l2tpv3"
The members of NetdevSocketOptions when type is "socket"
The members of NetdevVdeOptions when type is "vde"
The members of NetdevBridgeOptions when type is "bridge"
The members of NetdevHubPortOptions when type is "hubport"
The members of NetdevNetmapOptions when type is "netmap"
The members of NetdevVhostUserOptions when type is "vhost-user"
The members of NetdevVhostVDPAOptions when type is "vhost-vdpa"

Since¶

1.2

‘l2tpv3’ - since 2.1

`RxState` (Enum)¶

Packets receiving state

Values¶

normal: filter assigned packets according to the mac-table
none: don’t receive any assigned packet
all: receive all assigned packets

Since¶

1.6

`RxFilterInfo` (Object)¶

Rx-filter information for a NIC.

Members¶

name: string: net client name
promiscuous: boolean: whether promiscuous mode is enabled
multicast: RxState: multicast receive state
unicast: RxState: unicast receive state
vlan: RxState: vlan receive state (Since 2.0)
broadcast-allowed: boolean: whether to receive broadcast
multicast-overflow: boolean: multicast table is overflowed or not
unicast-overflow: boolean: unicast table is overflowed or not
main-mac: string: the main macaddr string
vlan-table: array of int: a list of active vlan id
unicast-table: array of string: a list of unicast macaddr string
multicast-table: array of string: a list of multicast macaddr string

Since¶

1.6

`query-rx-filter` (Command)¶

Return rx-filter information for all NICs (or for the given NIC).

Arguments¶

name: string (optional): net client name

Returns¶

list of RxFilterInfo for all NICs (or for the given NIC). Returns an error if the given name doesn’t exist, or given NIC doesn’t support rx-filter querying, or given net client isn’t a NIC.

Since¶

1.6

Example¶

-> { "execute": "query-rx-filter", "arguments": { "name": "vnet0" } }
<- { "return": [
        {
            "promiscuous": true,
            "name": "vnet0",
            "main-mac": "52:54:00:12:34:56",
            "unicast": "normal",
            "vlan": "normal",
            "vlan-table": [
                4,
                0
            ],
            "unicast-table": [
            ],
            "multicast": "normal",
            "multicast-overflow": false,
            "unicast-overflow": false,
            "multicast-table": [
                "01:00:5e:00:00:01",
                "33:33:00:00:00:01",
                "33:33:ff:12:34:56"
            ],
            "broadcast-allowed": false
        }
      ]
   }

`NIC_RX_FILTER_CHANGED` (Event)¶

Emitted once until the ‘query-rx-filter’ command is executed, the first event will always be emitted

Arguments¶

name: string (optional): net client name
path: string: device path

Since¶

1.6

Example¶

<- { "event": "NIC_RX_FILTER_CHANGED",
     "data": { "name": "vnet0",
               "path": "/machine/peripheral/vnet0/virtio-backend" },
     "timestamp": { "seconds": 1368697518, "microseconds": 326866 } }
   }

`AnnounceParameters` (Object)¶

Parameters for self-announce timers

Members¶

initial: int: Initial delay (in ms) before sending the first GARP/RARP announcement
max: int: Maximum delay (in ms) between GARP/RARP announcement packets
rounds: int: Number of self-announcement attempts
step: int: Delay increase (in ms) after each self-announcement attempt
interfaces: array of string (optional): An optional list of interface names, which restricts the announcement to the listed interfaces. (Since 4.1)
id: string (optional): A name to be used to identify an instance of announce-timers and to allow it to modified later. Not for use as part of the migration parameters. (Since 4.1)

Since¶

4.0

`announce-self` (Command)¶

Trigger generation of broadcast RARP frames to update network switches. This can be useful when network bonds fail-over the active slave.

Arguments¶

The members of AnnounceParameters

Example¶

-> { "execute": "announce-self",
     "arguments": {
         "initial": 50, "max": 550, "rounds": 10, "step": 50,
         "interfaces": ["vn2", "vn3"], "id": "bob" } }
<- { "return": {} }

Since¶

4.0

`FAILOVER_NEGOTIATED` (Event)¶

Emitted when VIRTIO_NET_F_STANDBY was enabled during feature negotiation. Failover primary devices which were hidden (not hotplugged when requested) before will now be hotplugged by the virtio-net standby device.

device-id: QEMU device id of the unplugged device

Arguments¶

device-id: string: Not documented

Since¶

4.2

Example¶

<- { "event": "FAILOVER_NEGOTIATED",
     "data": "net1" }

RDMA device¶

`RDMA_GID_STATUS_CHANGED` (Event)¶

Emitted when guest driver adds/deletes GID to/from device

Arguments¶

netdev: string: RoCE Network Device name
gid-status: boolean: Add or delete indication
subnet-prefix: int: Subnet Prefix
interface-id: int: Not documented

interface-id : Interface ID

Since¶

4.0

Example¶

<- {"timestamp": {"seconds": 1541579657, "microseconds": 986760},
    "event": "RDMA_GID_STATUS_CHANGED",
    "data":
        {"netdev": "bridge0",
        "interface-id": 15880512517475447892,
        "gid-status": true,
        "subnet-prefix": 33022}}

Rocker switch device¶

`RockerSwitch` (Object)¶

Rocker switch information.

Members¶

name: string: switch name
id: int: switch ID
ports: int: number of front-panel ports

Since¶

2.4

`query-rocker` (Command)¶

Return rocker switch information.

Arguments¶

name: string: Not documented

Returns¶

Rocker information

Since¶

2.4

Example¶

-> { "execute": "query-rocker", "arguments": { "name": "sw1" } }
<- { "return": {"name": "sw1", "ports": 2, "id": 1327446905938}}

`RockerPortDuplex` (Enum)¶

An eumeration of port duplex states.

Values¶

half: half duplex
full: full duplex

Since¶

2.4

`RockerPortAutoneg` (Enum)¶

An eumeration of port autoneg states.

Values¶

off: autoneg is off
on: autoneg is on

Since¶

2.4

`RockerPort` (Object)¶

Rocker switch port information.

Members¶

name: string: port name
enabled: boolean: port is enabled for I/O
link-up: boolean: physical link is UP on port
speed: int: port link speed in Mbps
duplex: RockerPortDuplex: port link duplex
autoneg: RockerPortAutoneg: port link autoneg

Since¶

2.4

`query-rocker-ports` (Command)¶

Return rocker switch port information.

Arguments¶

name: string: Not documented

Returns¶

a list of RockerPort information

Since¶

2.4

Example¶

-> { "execute": "query-rocker-ports", "arguments": { "name": "sw1" } }
<- { "return": [ {"duplex": "full", "enabled": true, "name": "sw1.1",
                  "autoneg": "off", "link-up": true, "speed": 10000},
                 {"duplex": "full", "enabled": true, "name": "sw1.2",
                  "autoneg": "off", "link-up": true, "speed": 10000}
   ]}

`RockerOfDpaFlowKey` (Object)¶

Rocker switch OF-DPA flow key

Members¶

priority: int: key priority, 0 being lowest priority
tbl-id: int: flow table ID
in-pport: int (optional): physical input port
tunnel-id: int (optional): tunnel ID
vlan-id: int (optional): VLAN ID
eth-type: int (optional): Ethernet header type
eth-src: string (optional): Ethernet header source MAC address
eth-dst: string (optional): Ethernet header destination MAC address
ip-proto: int (optional): IP Header protocol field
ip-tos: int (optional): IP header TOS field
ip-dst: string (optional): IP header destination address

Note¶

optional members may or may not appear in the flow key depending if they’re relevant to the flow key.

Since¶

2.4

`RockerOfDpaFlowMask` (Object)¶

Rocker switch OF-DPA flow mask

Members¶

in-pport: int (optional): physical input port
tunnel-id: int (optional): tunnel ID
vlan-id: int (optional): VLAN ID
eth-src: string (optional): Ethernet header source MAC address
eth-dst: string (optional): Ethernet header destination MAC address
ip-proto: int (optional): IP Header protocol field
ip-tos: int (optional): IP header TOS field

Note¶

optional members may or may not appear in the flow mask depending if they’re relevant to the flow mask.

Since¶

2.4

`RockerOfDpaFlowAction` (Object)¶

Rocker switch OF-DPA flow action

Members¶

goto-tbl: int (optional): next table ID
group-id: int (optional): group ID
tunnel-lport: int (optional): tunnel logical port ID
vlan-id: int (optional): VLAN ID
new-vlan-id: int (optional): new VLAN ID
out-pport: int (optional): physical output port

Note¶

optional members may or may not appear in the flow action depending if they’re relevant to the flow action.

Since¶

2.4

`RockerOfDpaFlow` (Object)¶

Rocker switch OF-DPA flow

Members¶

cookie: int: flow unique cookie ID
hits: int: count of matches (hits) on flow
key: RockerOfDpaFlowKey: flow key
mask: RockerOfDpaFlowMask: flow mask
action: RockerOfDpaFlowAction: flow action

Since¶

2.4

`query-rocker-of-dpa-flows` (Command)¶

Return rocker OF-DPA flow information.

Arguments¶

name: string: switch name
tbl-id: int (optional): flow table ID. If tbl-id is not specified, returns flow information for all tables.

Returns¶

rocker OF-DPA flow information

Since¶

2.4

Example¶

-> { "execute": "query-rocker-of-dpa-flows",
     "arguments": { "name": "sw1" } }
<- { "return": [ {"key": {"in-pport": 0, "priority": 1, "tbl-id": 0},
                  "hits": 138,
                  "cookie": 0,
                  "action": {"goto-tbl": 10},
                  "mask": {"in-pport": 4294901760}
                 },
                 {...more...},
   ]}

`RockerOfDpaGroup` (Object)¶

Rocker switch OF-DPA group

Members¶

id: int: group unique ID
type: int: group type
vlan-id: int (optional): VLAN ID
pport: int (optional): physical port number
index: int (optional): group index, unique with group type
out-pport: int (optional): output physical port number
group-id: int (optional): next group ID
set-vlan-id: int (optional): VLAN ID to set
pop-vlan: int (optional): pop VLAN headr from packet
group-ids: array of int (optional): list of next group IDs
set-eth-src: string (optional): set source MAC address in Ethernet header
set-eth-dst: string (optional): set destination MAC address in Ethernet header
ttl-check: int (optional): perform TTL check

Note¶

optional members may or may not appear in the group depending if they’re relevant to the group type.

Since¶

2.4

`query-rocker-of-dpa-groups` (Command)¶

Return rocker OF-DPA group information.

Arguments¶

name: string: switch name
type: int (optional): group type. If type is not specified, returns group information for all group types.

Returns¶

rocker OF-DPA group information

Since¶

2.4

Example¶

-> { "execute": "query-rocker-of-dpa-groups",
     "arguments": { "name": "sw1" } }
<- { "return": [ {"type": 0, "out-pport": 2,
                  "pport": 2, "vlan-id": 3841,
                  "pop-vlan": 1, "id": 251723778},
                 {"type": 0, "out-pport": 0,
                  "pport": 0, "vlan-id": 3841,
                  "pop-vlan": 1, "id": 251723776},
                 {"type": 0, "out-pport": 1,
                  "pport": 1, "vlan-id": 3840,
                  "pop-vlan": 1, "id": 251658241},
                 {"type": 0, "out-pport": 0,
                  "pport": 0, "vlan-id": 3840,
                  "pop-vlan": 1, "id": 251658240}
   ]}

TPM (trusted platform module) devices¶

`TpmModel` (Enum)¶

An enumeration of TPM models

Values¶

tpm-tis: TPM TIS model
tpm-crb: TPM CRB model (since 2.12)
tpm-spapr: TPM SPAPR model (since 5.0)

Since¶

1.5

`query-tpm-models` (Command)¶

Return a list of supported TPM models

Returns¶

a list of TpmModel

Since¶

1.5

Example¶

-> { "execute": "query-tpm-models" }
<- { "return": [ "tpm-tis", "tpm-crb", "tpm-spapr" ] }

`TpmType` (Enum)¶

An enumeration of TPM types

Values¶

passthrough: TPM passthrough type
emulator: Software Emulator TPM type Since: 2.11

Since¶

1.5

`query-tpm-types` (Command)¶

Return a list of supported TPM types

Returns¶

a list of TpmType

Since¶

1.5

Example¶

-> { "execute": "query-tpm-types" }
<- { "return": [ "passthrough", "emulator" ] }

`TPMPassthroughOptions` (Object)¶

Information about the TPM passthrough type

Members¶

path: string (optional): string describing the path used for accessing the TPM device
cancel-path: string (optional): string showing the TPM’s sysfs cancel file for cancellation of TPM commands while they are executing

Since¶

1.5

`TPMEmulatorOptions` (Object)¶

Information about the TPM emulator type

Members¶

chardev: string: Name of a unix socket chardev

Since¶

2.11

`TpmTypeOptions` (Object)¶

A union referencing different TPM backend types’ configuration options

Members¶

type

‘passthrough’ The configuration options for the TPM passthrough type
‘emulator’ The configuration options for TPM emulator backend type

data: TPMPassthroughOptions when type is "passthrough"

`set_password` (Command)¶

Sets the password of a remote display session.

Arguments¶

protocol: string

‘vnc’ to modify the VNC server password
‘spice’ to modify the Spice server password

password: string

the new password

connected: string (optional)

how to handle existing clients when changing the password. If nothing is specified, defaults to ‘keep’ ‘fail’ to fail the command if clients are connected ‘disconnect’ to disconnect existing clients ‘keep’ to maintain existing clients

Returns¶

Nothing on success
If Spice is not enabled, DeviceNotFound

Since¶

0.14

Example¶

-> { "execute": "set_password", "arguments": { "protocol": "vnc",
                                               "password": "secret" } }
<- { "return": {} }

`expire_password` (Command)¶

Expire the password of a remote display server.

Arguments¶

protocol: string

the name of the remote display protocol ‘vnc’ or ‘spice’

time: string

when to expire the password.

‘now’ to expire the password immediately
‘never’ to cancel password expiration
‘+INT’ where INT is the number of seconds from now (integer)
‘INT’ where INT is the absolute time in seconds

Returns¶

Nothing on success
If protocol is ‘spice’ and Spice is not active, DeviceNotFound

Since¶

0.14

Notes¶

Time is relative to the server and currently there is no way to coordinate server time with client time. It is not recommended to use the absolute time version of the time parameter unless you’re sure you are on the same machine as the QEMU instance.

Example¶

-> { "execute": "expire_password", "arguments": { "protocol": "vnc",
                                                  "time": "+60" } }
<- { "return": {} }

`screendump` (Command)¶

Write a PPM of the VGA screen to a file.

Arguments¶

filename: string: the path of a new PPM file to store the image
device: string (optional): ID of the display device that should be dumped. If this parameter is missing, the primary display will be used. (Since 2.12)
head: int (optional): head to use in case the device supports multiple heads. If this parameter is missing, head #0 will be used. Also note that the head can only be specified in conjunction with the device ID. (Since 2.12)

Returns¶

Nothing on success

Since¶

0.14

Example¶

-> { "execute": "screendump",
     "arguments": { "filename": "/tmp/image" } }
<- { "return": {} }

Spice¶

`SpiceBasicInfo` (Object)¶

The basic information for SPICE network connection

Members¶

host: string: IP address
port: string: port number
family: NetworkAddressFamily: address family

Since¶

2.1

If¶

defined(CONFIG_SPICE)

`SpiceServerInfo` (Object)¶

Information about a SPICE server

Members¶

auth: string (optional): authentication method
The members of SpiceBasicInfo

Since¶

2.1

If¶

defined(CONFIG_SPICE)

`SpiceChannel` (Object)¶

Information about a SPICE client channel.

Members¶

connection-id: int: SPICE connection id number. All channels with the same id belong to the same SPICE session.
channel-type: int: SPICE channel type number. “1” is the main control channel, filter for this one if you want to track spice sessions only
channel-id: int: SPICE channel ID number. Usually “0”, might be different when multiple channels of the same type exist, such as multiple display channels in a multihead setup
tls: boolean: true if the channel is encrypted, false otherwise.
The members of SpiceBasicInfo

Since¶

0.14

If¶

defined(CONFIG_SPICE)

`SpiceQueryMouseMode` (Enum)¶

An enumeration of Spice mouse states.

Values¶

client: Mouse cursor position is determined by the client.
server: Mouse cursor position is determined by the server.
unknown: No information is available about mouse mode used by the spice server.

Note¶

spice/enums.h has a SpiceMouseMode already, hence the name.

Since¶

1.1

If¶

defined(CONFIG_SPICE)

`SpiceInfo` (Object)¶

Information about the SPICE session.

Members¶

enabled: boolean

true if the SPICE server is enabled, false otherwise

migrated: boolean

true if the last guest migration completed and spice migration had completed as well. false otherwise. (since 1.4)

host: string (optional)

The hostname the SPICE server is bound to. This depends on the name resolution on the host and may be an IP address.

port: int (optional)

The SPICE server’s port number.

compiled-version: string (optional)

SPICE server version.

tls-port: int (optional)

The SPICE server’s TLS port number.

auth: string (optional)

the current authentication type used by the server

‘none’ if no authentication is being used
‘spice’ uses SASL or direct TLS authentication, depending on command line options

mouse-mode: SpiceQueryMouseMode

The mode in which the mouse cursor is displayed currently. Can be determined by the client or the server, or unknown if spice server doesn’t provide this information. (since: 1.1)

channels: array of SpiceChannel (optional)

a list of SpiceChannel for each active spice channel

Since¶

0.14

If¶

defined(CONFIG_SPICE)

`query-spice` (Command)¶

Returns information about the current SPICE server

Returns¶

SpiceInfo

Since¶

0.14

Example¶

-> { "execute": "query-spice" }
<- { "return": {
         "enabled": true,
         "auth": "spice",
         "port": 5920,
         "tls-port": 5921,
         "host": "0.0.0.0",
         "channels": [
            {
               "port": "54924",
               "family": "ipv4",
               "channel-type": 1,
               "connection-id": 1804289383,
               "host": "127.0.0.1",
               "channel-id": 0,
               "tls": true
            },
            {
               "port": "36710",
               "family": "ipv4",
               "channel-type": 4,
               "connection-id": 1804289383,
               "host": "127.0.0.1",
               "channel-id": 0,
               "tls": false
            },
            [ ... more channels follow ... ]
         ]
      }
   }

If¶

defined(CONFIG_SPICE)

`SPICE_CONNECTED` (Event)¶

Emitted when a SPICE client establishes a connection

Arguments¶

server: SpiceBasicInfo: server information
client: SpiceBasicInfo: client information

Since¶

0.14

Example¶

<- { "timestamp": {"seconds": 1290688046, "microseconds": 388707},
     "event": "SPICE_CONNECTED",
     "data": {
       "server": { "port": "5920", "family": "ipv4", "host": "127.0.0.1"},
       "client": {"port": "52873", "family": "ipv4", "host": "127.0.0.1"}
   }}

If¶

defined(CONFIG_SPICE)

`SPICE_INITIALIZED` (Event)¶

Emitted after initial handshake and authentication takes place (if any) and the SPICE channel is up and running

Arguments¶

server: SpiceServerInfo: server information
client: SpiceChannel: client information

Since¶

0.14

Example¶

<- { "timestamp": {"seconds": 1290688046, "microseconds": 417172},
     "event": "SPICE_INITIALIZED",
     "data": {"server": {"auth": "spice", "port": "5921",
                         "family": "ipv4", "host": "127.0.0.1"},
              "client": {"port": "49004", "family": "ipv4", "channel-type": 3,
                         "connection-id": 1804289383, "host": "127.0.0.1",
                         "channel-id": 0, "tls": true}
   }}

If¶

defined(CONFIG_SPICE)

`SPICE_DISCONNECTED` (Event)¶

Emitted when the SPICE connection is closed

Arguments¶

server: SpiceBasicInfo: server information
client: SpiceBasicInfo: client information

Since¶

0.14

Example¶

<- { "timestamp": {"seconds": 1290688046, "microseconds": 388707},
     "event": "SPICE_DISCONNECTED",
     "data": {
       "server": { "port": "5920", "family": "ipv4", "host": "127.0.0.1"},
       "client": {"port": "52873", "family": "ipv4", "host": "127.0.0.1"}
   }}

If¶

defined(CONFIG_SPICE)

`SPICE_MIGRATE_COMPLETED` (Event)¶

Emitted when SPICE migration has completed

Since¶

1.3

Example¶

<- { "timestamp": {"seconds": 1290688046, "microseconds": 417172},
     "event": "SPICE_MIGRATE_COMPLETED" }

If¶

defined(CONFIG_SPICE)

VNC¶

`VncBasicInfo` (Object)¶

The basic information for vnc network connection

Members¶

host: string: IP address
service: string: The service name of the vnc port. This may depend on the host system’s service database so symbolic names should not be relied on.
family: NetworkAddressFamily: address family
websocket: boolean: true in case the socket is a websocket (since 2.3).

Since¶

2.1

If¶

defined(CONFIG_VNC)

`VncServerInfo` (Object)¶

The network connection information for server

Members¶

auth: string (optional): authentication method used for the plain (non-websocket) VNC server
The members of VncBasicInfo

Since¶

2.1

If¶

defined(CONFIG_VNC)

`VncClientInfo` (Object)¶

Information about a connected VNC client.

Members¶

x509_dname: string (optional): If x509 authentication is in use, the Distinguished Name of the client.
sasl_username: string (optional): If SASL authentication is in use, the SASL username used for authentication.
The members of VncBasicInfo

Since¶

0.14

If¶

defined(CONFIG_VNC)

`VncInfo` (Object)¶

Information about the VNC session.

Members¶

enabled: boolean

true if the VNC server is enabled, false otherwise

host: string (optional)

The hostname the VNC server is bound to. This depends on the name resolution on the host and may be an IP address.

family: NetworkAddressFamily (optional)

‘ipv6’ if the host is listening for IPv6 connections
‘ipv4’ if the host is listening for IPv4 connections
‘unix’ if the host is listening on a unix domain socket
‘unknown’ otherwise

service: string (optional)

The service name of the server’s port. This may depends on the host system’s service database so symbolic names should not be relied on.

auth: string (optional)

the current authentication type used by the server

‘none’ if no authentication is being used
‘vnc’ if VNC authentication is being used
‘vencrypt+plain’ if VEncrypt is used with plain text authentication
‘vencrypt+tls+none’ if VEncrypt is used with TLS and no authentication
‘vencrypt+tls+vnc’ if VEncrypt is used with TLS and VNC authentication
‘vencrypt+tls+plain’ if VEncrypt is used with TLS and plain text auth
‘vencrypt+x509+none’ if VEncrypt is used with x509 and no auth
‘vencrypt+x509+vnc’ if VEncrypt is used with x509 and VNC auth
‘vencrypt+x509+plain’ if VEncrypt is used with x509 and plain text auth
‘vencrypt+tls+sasl’ if VEncrypt is used with TLS and SASL auth
‘vencrypt+x509+sasl’ if VEncrypt is used with x509 and SASL auth

clients: array of VncClientInfo (optional)

server: VncServerInfo: server information
client: VncClientInfo: client information

Since¶

0.13

Example¶

<-  { "event": "VNC_INITIALIZED",
      "data": {
           "server": { "auth": "sasl", "family": "ipv4",
                       "service": "5901", "host": "0.0.0.0"},
           "client": { "family": "ipv4", "service": "46089",
                       "host": "127.0.0.1", "sasl_username": "luiz" } },
      "timestamp": { "seconds": 1263475302, "microseconds": 150772 } }

If¶

defined(CONFIG_VNC)

`VNC_DISCONNECTED` (Event)¶

Emitted when the connection is closed

Arguments¶

server: VncServerInfo: server information
client: VncClientInfo: client information

Since¶

0.13

Example¶

<- { "event": "VNC_DISCONNECTED",
     "data": {
           "server": { "auth": "sasl", "family": "ipv4",
                       "service": "5901", "host": "0.0.0.0" },
           "client": { "family": "ipv4", "service": "58425",
                       "host": "127.0.0.1", "sasl_username": "luiz" } },
     "timestamp": { "seconds": 1262976601, "microseconds": 975795 } }

If¶

defined(CONFIG_VNC)

Input¶

`MouseInfo` (Object)¶

Information about a mouse device.

Members¶

name: string: the name of the mouse device
index: int: the index of the mouse device
current: boolean: true if this device is currently receiving mouse events
absolute: boolean: true if this device supports absolute coordinates as input

Since¶

0.14

`query-mice` (Command)¶

Returns information about each active mouse device

Returns¶

a list of MouseInfo for each device

Since¶

0.14

Example¶

-> { "execute": "query-mice" }
<- { "return": [
         {
            "name":"QEMU Microsoft Mouse",
            "index":0,
            "current":false,
            "absolute":false
         },
         {
            "name":"QEMU PS/2 Mouse",
            "index":1,
            "current":true,
            "absolute":true
         }
      ]
   }

`QKeyCode` (Enum)¶

An enumeration of key name.

This is used by the send-key command.

Values¶

unmapped: since 2.0
pause: since 2.0
ro: since 2.4
kp_comma: since 2.4
kp_equals: since 2.6
power: since 2.6
hiragana: since 2.9
henkan: since 2.9
yen: since 2.9
sleep: since 2.10
wake: since 2.10
audionext: since 2.10
audioprev: since 2.10
audiostop: since 2.10
audioplay: since 2.10
audiomute: since 2.10
volumeup: since 2.10
volumedown: since 2.10
mediaselect: since 2.10
mail: since 2.10
calculator: since 2.10
computer: since 2.10
ac_home: since 2.10
ac_back: since 2.10
ac_forward: since 2.10
ac_refresh: since 2.10
ac_bookmarks: since 2.10
muhenkan: since 2.12
katakanahiragana: since 2.12
shift: Not documented
shift_r: Not documented
alt: Not documented
alt_r: Not documented
ctrl: Not documented
ctrl_r: Not documented
menu: Not documented
esc: Not documented
1: Not documented
2: Not documented
3: Not documented
4: Not documented
5: Not documented
6: Not documented
7: Not documented
8: Not documented
9: Not documented
0: Not documented
minus: Not documented
equal: Not documented
backspace: Not documented
tab: Not documented
q: Not documented
w: Not documented
e: Not documented
r: Not documented
t: Not documented
y: Not documented
u: Not documented
i: Not documented
o: Not documented
p: Not documented
bracket_left: Not documented
bracket_right: Not documented
ret: Not documented
a: Not documented
s: Not documented
d: Not documented
f: Not documented
g: Not documented
h: Not documented
j: Not documented
k: Not documented
l: Not documented
semicolon: Not documented
apostrophe: Not documented
grave_accent: Not documented
backslash: Not documented
z: Not documented
x: Not documented
c: Not documented
v: Not documented
b: Not documented
n: Not documented
m: Not documented
comma: Not documented
dot: Not documented
slash: Not documented
asterisk: Not documented
spc: Not documented
caps_lock: Not documented
f1: Not documented
f2: Not documented
f3: Not documented
f4: Not documented
f5: Not documented
f6: Not documented
f7: Not documented
f8: Not documented
f9: Not documented
f10: Not documented
num_lock: Not documented
scroll_lock: Not documented
kp_divide: Not documented
kp_multiply: Not documented
kp_subtract: Not documented
kp_add: Not documented
kp_enter: Not documented
kp_decimal: Not documented
sysrq: Not documented
kp_0: Not documented
kp_1: Not documented
kp_2: Not documented
kp_3: Not documented
kp_4: Not documented
kp_5: Not documented
kp_6: Not documented
kp_7: Not documented
kp_8: Not documented
kp_9: Not documented
less: Not documented
f11: Not documented
f12: Not documented
print: Not documented
home: Not documented
pgup: Not documented
pgdn: Not documented
end: Not documented
left: Not documented
up: Not documented
down: Not documented
right: Not documented
insert: Not documented
delete: Not documented
stop: Not documented
again: Not documented
props: Not documented
undo: Not documented
front: Not documented
copy: Not documented
open: Not documented
paste: Not documented
find: Not documented
cut: Not documented
lf: Not documented
help: Not documented
meta_l: Not documented
meta_r: Not documented
compose: Not documented

‘sysrq’ was mistakenly added to hack around the fact that the ps2 driver was not generating correct scancodes sequences when ‘alt+print’ was pressed. This flaw is now fixed and the ‘sysrq’ key serves no further purpose. Any further use of ‘sysrq’ will be transparently changed to ‘print’, so they are effectively synonyms.

Since¶

1.3

`KeyValue` (Object)¶

Represents a keyboard key.

Members¶

type: One of number, qcode
data: int when type is "number"
data: QKeyCode when type is "qcode"

Since¶

1.3

`send-key` (Command)¶

Send keys to guest.

Arguments¶

keys: array of KeyValue: An array of KeyValue elements. All KeyValues in this array are simultaneously sent to the guest. A KeyValue.number value is sent directly to the guest, while KeyValue.qcode must be a valid QKeyCode value
hold-time: int (optional): time to delay key up events, milliseconds. Defaults to 100

Returns¶

Nothing on success
If key is unknown or redundant, InvalidParameter

Since¶

1.3

Example¶

-> { "execute": "send-key",
     "arguments": { "keys": [ { "type": "qcode", "data": "ctrl" },
                              { "type": "qcode", "data": "alt" },
                              { "type": "qcode", "data": "delete" } ] } }
<- { "return": {} }

`InputButton` (Enum)¶

Button of a pointer input device (mouse, tablet).

Values¶

side: front side button of a 5-button mouse (since 2.9)
extra: rear side button of a 5-button mouse (since 2.9)
left: Not documented
middle: Not documented
right: Not documented
wheel-up: Not documented
wheel-down: Not documented

Since¶

2.0

`InputAxis` (Enum)¶

Position axis of a pointer input device (mouse, tablet).

Values¶

x: Not documented
y: Not documented

Since¶

2.0

`InputKeyEvent` (Object)¶

Keyboard input event.

Members¶

key: KeyValue: Which key this event is for.
down: boolean: True for key-down and false for key-up events.

Since¶

2.0

`InputBtnEvent` (Object)¶

Pointer button input event.

Members¶

button: InputButton: Which button this event is for.
down: boolean: True for key-down and false for key-up events.

Since¶

2.0

`InputMoveEvent` (Object)¶

Pointer motion input event.

Members¶

axis: InputAxis: Which axis is referenced by value.
value: int: Pointer position. For absolute coordinates the valid range is 0 -> 0x7ffff

Since¶

2.0

`InputEvent` (Object)¶

Input event union.

Members¶

type

the input type, one of:

‘key’: Input event of Keyboard
‘btn’: Input event of pointer buttons
‘rel’: Input event of relative pointer motion
‘abs’: Input event of absolute pointer motion

data: InputKeyEvent when type is "key"

data: InputBtnEvent when type is "btn"

data: InputMoveEvent when type is "rel"

data: InputMoveEvent when type is "abs"

Since¶

2.0

`input-send-event` (Command)¶

Send input event(s) to guest.

The device and head parameters can be used to send the input event to specific input devices in case (a) multiple input devices of the same kind are added to the virtual machine and (b) you have configured input routing (see docs/multiseat.txt) for those input devices. The parameters work exactly like the device and head properties of input devices. If device is missing, only devices that have no input routing config are admissible. If device is specified, both input devices with and without input routing config are admissible, but devices with input routing config take precedence.

Arguments¶

device: string (optional): display device to send event(s) to.
head: int (optional): head to send event(s) to, in case the display device supports multiple scanouts.
events: array of InputEvent: List of InputEvent union.

Returns¶

Nothing on success.

Since¶

2.6

Note¶

The consoles are visible in the qom tree, under /backend/console[$index]. They have a device link and head property, so it is possible to map which console belongs to which device and display.

Example¶

1. Press left mouse button.

-> { "execute": "input-send-event",
    "arguments": { "device": "video0",
                   "events": [ { "type": "btn",
                   "data" : { "down": true, "button": "left" } } ] } }
<- { "return": {} }

-> { "execute": "input-send-event",
    "arguments": { "device": "video0",
                   "events": [ { "type": "btn",
                   "data" : { "down": false, "button": "left" } } ] } }
<- { "return": {} }

2. Press ctrl-alt-del.

-> { "execute": "input-send-event",
     "arguments": { "events": [
        { "type": "key", "data" : { "down": true,
          "key": {"type": "qcode", "data": "ctrl" } } },
        { "type": "key", "data" : { "down": true,
          "key": {"type": "qcode", "data": "alt" } } },
        { "type": "key", "data" : { "down": true,
          "key": {"type": "qcode", "data": "delete" } } } ] } }
<- { "return": {} }

3. Move mouse pointer to absolute coordinates (20000, 400).

-> { "execute": "input-send-event" ,
  "arguments": { "events": [
               { "type": "abs", "data" : { "axis": "x", "value" : 20000 } },
               { "type": "abs", "data" : { "axis": "y", "value" : 400 } } ] } }
<- { "return": {} }

`DisplayGTK` (Object)¶

GTK display options.

Members¶

grab-on-hover: boolean (optional): Grab keyboard input on mouse hover.
zoom-to-fit: boolean (optional): Zoom guest display to fit into the host window. When turned off the host window will be resized instead. In case the display device can notify the guest on window resizes (virtio-gpu) this will default to “on”, assuming the guest will resize the display to match the window size then. Otherwise it defaults to “off”. Since 3.1

Since¶

2.12

`DisplayEGLHeadless` (Object)¶

EGL headless display options.

Members¶

rendernode: string (optional): Which DRM render node should be used. Default is the first available node on the host.

Since¶

3.1

`DisplayGLMode` (Enum)¶

Display OpenGL mode.

Values¶

off: Disable OpenGL (default).
on: Use OpenGL, pick context type automatically. Would better be named ‘auto’ but is called ‘on’ for backward compatibility with bool type.
core: Use OpenGL with Core (desktop) Context.
es: Use OpenGL with ES (embedded systems) Context.

Since¶

3.0

`DisplayCurses` (Object)¶

Curses display options.

Members¶

charset: string (optional): Font charset used by guest (default: CP437).

Since¶

4.0

`DisplayType` (Enum)¶

Display (user interface) type.

Values¶

default: The default user interface, selecting from the first available of gtk, sdl, cocoa, and vnc.
none: No user interface or video output display. The guest will still see an emulated graphics card, but its output will not be displayed to the QEMU user.
gtk: The GTK user interface.
sdl: The SDL user interface.
egl-headless: No user interface, offload GL operations to a local DRI device. Graphical display need to be paired with VNC or Spice. (Since 3.1)
curses: Display video output via curses. For graphics device models which support a text mode, QEMU can display this output using a curses/ncurses interface. Nothing is displayed when the graphics device is in graphical mode or if the graphics device does not support a text mode. Generally only the VGA device models support text mode.
cocoa: The Cocoa user interface.
spice-app: Set up a Spice server and run the default associated application to connect to it. The server will redirect the serial console and QEMU monitors. (Since 4.0)

Since¶

2.12

`DisplayOptions` (Object)¶

Display (user interface) options.

Members¶

type: DisplayType: Which DisplayType qemu should use.
full-screen: boolean (optional): Start user interface in fullscreen mode (default: off).
window-close: boolean (optional): Allow to quit qemu with window close button (default: on).
show-cursor: boolean (optional): Force showing the mouse cursor (default: off). (since: 5.0)
gl: DisplayGLMode (optional): Enable OpenGL support (default: off).
The members of DisplayGTK when type is "gtk"
The members of DisplayCurses when type is "curses"
The members of DisplayEGLHeadless when type is "egl-headless"

User authorization¶

`QAuthZListPolicy` (Enum)¶

The authorization policy result

Values¶

deny: deny access
allow: allow access

Since¶

4.0

`QAuthZListFormat` (Enum)¶

The authorization policy match format

Values¶

exact: an exact string match
glob: string with ? and * shell wildcard support

Since¶

4.0

`QAuthZListRule` (Object)¶

A single authorization rule.

Members¶

match: string: a string or glob to match against a user identity
policy: QAuthZListPolicy: the result to return if match evaluates to true
format: QAuthZListFormat (optional): the format of the match rule (default ‘exact’)

Since¶

4.0

`AuthZListProperties` (Object)¶

Properties for authz-list objects.

Members¶

policy: QAuthZListPolicy (optional): Default policy to apply when no rule matches (default: deny)
rules: array of QAuthZListRule (optional): Authorization rules based on matching user

Since¶

4.0

`AuthZListFileProperties` (Object)¶

Properties for authz-listfile objects.

Members¶

filename: string: File name to load the configuration from. The file must contain valid JSON for AuthZListProperties.
refresh: boolean (optional): If true, inotify is used to monitor the file, automatically reloading changes. If an error occurs during reloading, all authorizations will fail until the file is next successfully loaded. (default: true if the binary was built with CONFIG_INOTIFY1, false otherwise)

Since¶

4.0

`AuthZPAMProperties` (Object)¶

Properties for authz-pam objects.

Members¶

service: string: PAM service name to use for authorization

Since¶

4.0

`AuthZSimpleProperties` (Object)¶

Properties for authz-simple objects.

Members¶

identity: string: Identifies the allowed user. Its format depends on the network service that authorization object is associated with. For authorizing based on TLS x509 certificates, the identity must be the x509 distinguished name.

Since¶

4.0

Migration¶

`MigrationStats` (Object)¶

Detailed migration status.

Members¶

transferred: int: amount of bytes already transferred to the target VM
remaining: int: amount of bytes remaining to be transferred to the target VM
total: int: total amount of bytes involved in the migration process
duplicate: int: number of duplicate (zero) pages (since 1.2)
skipped: int: number of skipped zero pages (since 1.5)
normal: int: number of normal pages (since 1.2)
normal-bytes: int: number of normal bytes sent (since 1.2)
dirty-pages-rate: int: number of pages dirtied by second by the guest (since 1.3)
mbps: number: throughput in megabits/sec. (since 1.6)
dirty-sync-count: int: number of times that dirty ram was synchronized (since 2.1)
postcopy-requests: int: The number of page requests received from the destination (since 2.7)
page-size: int: The number of bytes per page for the various page-based statistics (since 2.10)
multifd-bytes: int: The number of bytes sent through multifd (since 3.0)
pages-per-second: int: the number of memory pages transferred per second (Since 4.0)

Since¶

0.14

`XBZRLECacheStats` (Object)¶

Detailed XBZRLE migration cache statistics

Members¶

cache-size: int: XBZRLE cache size
bytes: int: amount of bytes already transferred to the target VM
pages: int: amount of pages transferred to the target VM
cache-miss: int: number of cache miss
cache-miss-rate: number: rate of cache miss (since 2.1)
encoding-rate: number: rate of encoded bytes (since 5.1)
overflow: int: number of overflows

Since¶

1.2

`CompressionStats` (Object)¶

Detailed migration compression statistics

Members¶

pages: int: amount of pages compressed and transferred to the target VM
busy: int: count of times that no free thread was available to compress data
busy-rate: number: rate of thread busy
compressed-size: int: amount of bytes after compression
compression-rate: number: rate of compressed size

Since¶

3.1

`MigrationStatus` (Enum)¶

An enumeration of migration status.

Values¶

none: no migration has ever happened.
setup: migration process has been initiated.
cancelling: in the process of cancelling migration.
cancelled: cancelling migration is finished.
active: in the process of doing migration.
postcopy-active: like active, but now in postcopy mode. (since 2.5)
postcopy-paused: during postcopy but paused. (since 3.0)
postcopy-recover: trying to recover from a paused postcopy. (since 3.0)
completed: migration is finished.
failed: some error occurred during migration process.
colo: VM is in the process of fault tolerance, VM can not get into this state unless colo capability is enabled for migration. (since 2.8)
pre-switchover: Paused before device serialisation. (since 2.11)
device: During device serialisation when pause-before-switchover is enabled (since 2.11)
wait-unplug: wait for device unplug request by guest OS to be completed. (since 4.2)

Since¶

2.3

`VfioStats` (Object)¶

Detailed VFIO devices migration statistics

Members¶

transferred: int: amount of bytes transferred to the target VM by VFIO devices

Since¶

5.2

`MigrationInfo` (Object)¶

Information about current migration process.

Members¶

status: MigrationStatus (optional): MigrationStatus describing the current migration status. If this field is not returned, no migration process has been initiated
ram: MigrationStats (optional): MigrationStats containing detailed migration status, only returned if status is ‘active’ or ‘completed’(since 1.2)
disk: MigrationStats (optional): MigrationStats containing detailed disk migration status, only returned if status is ‘active’ and it is a block migration
xbzrle-cache: XBZRLECacheStats (optional): XBZRLECacheStats containing detailed XBZRLE migration statistics, only returned if XBZRLE feature is on and status is ‘active’ or ‘completed’ (since 1.2)
total-time: int (optional): total amount of milliseconds since migration started. If migration has ended, it returns the total migration time. (since 1.2)
downtime: int (optional): only present when migration finishes correctly total downtime in milliseconds for the guest. (since 1.3)
expected-downtime: int (optional): only present while migration is active expected downtime in milliseconds for the guest in last walk of the dirty bitmap. (since 1.3)
setup-time: int (optional): amount of setup time in milliseconds before the iterations begin but after the QMP command is issued. This is designed to provide an accounting of any activities (such as RDMA pinning) which may be expensive, but do not actually occur during the iterative migration rounds themselves. (since 1.6)
cpu-throttle-percentage: int (optional): percentage of time guest cpus are being throttled during auto-converge. This is only present when auto-converge has started throttling guest cpus. (Since 2.7)
error-desc: string (optional): the human readable error description string, when status is ‘failed’. Clients should not attempt to parse the error strings. (Since 2.7)
postcopy-blocktime: int (optional): total time when all vCPU were blocked during postcopy live migration. This is only present when the postcopy-blocktime migration capability is enabled. (Since 3.0)
postcopy-vcpu-blocktime: array of int (optional): list of the postcopy blocktime per vCPU. This is only present when the postcopy-blocktime migration capability is enabled. (Since 3.0)
compression: CompressionStats (optional): migration compression statistics, only returned if compression feature is on and status is ‘active’ or ‘completed’ (Since 3.1)
socket-address: array of SocketAddress (optional): Only used for tcp, to know what the real port is (Since 4.0)
vfio: VfioStats (optional): VfioStats containing detailed VFIO devices migration statistics, only returned if VFIO device is present, migration is supported by all VFIO devices and status is ‘active’ or ‘completed’ (since 5.2)
blocked-reasons: array of string (optional): A list of reasons an outgoing migration is blocked. Present and non-empty when migration is blocked. (since 6.0)
blocked: boolean: True if outgoing migration is blocked (since 6.0)

Features¶

deprecated: Member blocked is deprecated. Use blocked-reasons instead.

Arguments¶

capabilities: array of MigrationCapabilityStatus: json array of capability modifications to make

Since¶

1.2

Example¶

-> { "execute": "migrate-set-capabilities" , "arguments":
     { "capabilities": [ { "capability": "xbzrle", "state": true } ] } }

`query-migrate-capabilities` (Command)¶

Returns information about the current migration capabilities status

Returns¶

MigrationCapabilitiesStatus

Since¶

1.2

Example¶

-> { "execute": "query-migrate-capabilities" }
<- { "return": [
      {"state": false, "capability": "xbzrle"},
      {"state": false, "capability": "rdma-pin-all"},
      {"state": false, "capability": "auto-converge"},
      {"state": false, "capability": "zero-blocks"},
      {"state": false, "capability": "compress"},
      {"state": true, "capability": "events"},
      {"state": false, "capability": "postcopy-ram"},
      {"state": false, "capability": "x-colo"}
   ]}

`MultiFDCompression` (Enum)¶

An enumeration of multifd compression methods.

Values¶

none: no compression.
zlib: use zlib compression method.
zstd (If: defined(CONFIG_ZSTD)): use zstd compression method.

Since¶

5.0

`BitmapMigrationBitmapAliasTransform` (Object)¶

Members¶

persistent: boolean (optional): If present, the bitmap will be made persistent or transient depending on this parameter.

Since¶

6.0

`BitmapMigrationBitmapAlias` (Object)¶

Members¶

name: string: The name of the bitmap.
alias: string: An alias name for migration (for example the bitmap name on the opposite site).
transform: BitmapMigrationBitmapAliasTransform (optional): Allows the modification of the migrated bitmap. (since 6.0)

Since¶

5.2

`BitmapMigrationNodeAlias` (Object)¶

Maps a block node name and the bitmaps it has to aliases for dirty bitmap migration.

Members¶

node-name: string: A block node name.
alias: string: An alias block node name for migration (for example the node name on the opposite site).
bitmaps: array of BitmapMigrationBitmapAlias: Mappings for the bitmaps on this node.

Since¶

5.2

`MigrationParameter` (Enum)¶

Migration parameters enumeration

Values¶

announce-initial: Initial delay (in milliseconds) before sending the first announce (Since 4.0)
announce-max: Maximum delay (in milliseconds) between packets in the announcement (Since 4.0)
announce-rounds: Number of self-announce packets sent after migration (Since 4.0)
announce-step: Increase in delay (in milliseconds) between subsequent packets in the announcement (Since 4.0)
compress-level: Set the compression level to be used in live migration, the compression level is an integer between 0 and 9, where 0 means no compression, 1 means the best compression speed, and 9 means best compression ratio which will consume more CPU.
compress-threads: Set compression thread count to be used in live migration, the compression thread count is an integer between 1 and 255.
compress-wait-thread: Controls behavior when all compression threads are currently busy. If true (default), wait for a free compression thread to become available; otherwise, send the page uncompressed. (Since 3.1)
decompress-threads: Set decompression thread count to be used in live migration, the decompression thread count is an integer between 1 and 255. Usually, decompression is at least 4 times as fast as compression, so set the decompress-threads to the number about 1/4 of compress-threads is adequate.
throttle-trigger-threshold: The ratio of bytes_dirty_period and bytes_xfer_period to trigger throttling. It is expressed as percentage. The default value is 50. (Since 5.0)
cpu-throttle-initial: Initial percentage of time guest cpus are throttled when migration auto-converge is activated. The default value is 20. (Since 2.7)
cpu-throttle-increment: throttle percentage increase each time auto-converge detects that migration is not making progress. The default value is 10. (Since 2.7)
cpu-throttle-tailslow: Make CPU throttling slower at tail stage At the tail stage of throttling, the Guest is very sensitive to CPU percentage while the cpu-throttle -increment is excessive usually at tail stage. If this parameter is true, we will compute the ideal CPU percentage used by the Guest, which may exactly make the dirty rate match the dirty rate threshold. Then we will choose a smaller throttle increment between the one specified by cpu-throttle-increment and the one generated by ideal CPU percentage. Therefore, it is compatible to traditional throttling, meanwhile the throttle increment won’t be excessive at tail stage. The default value is false. (Since 5.1)
tls-creds: ID of the ‘tls-creds’ object that provides credentials for establishing a TLS connection over the migration data channel. On the outgoing side of the migration, the credentials must be for a ‘client’ endpoint, while for the incoming side the credentials must be for a ‘server’ endpoint. Setting this will enable TLS for all migrations. The default is unset, resulting in unsecured migration at the QEMU level. (Since 2.7)
tls-hostname: hostname of the target host for the migration. This is required when using x509 based TLS credentials and the migration URI does not already include a hostname. For example if using fd: or exec: based migration, the hostname must be provided so that the server’s x509 certificate identity can be validated. (Since 2.7)
tls-authz: ID of the ‘authz’ object subclass that provides access control checking of the TLS x509 certificate distinguished name. This object is only resolved at time of use, so can be deleted and recreated on the fly while the migration server is active. If missing, it will default to denying access (Since 4.0)
max-bandwidth: to set maximum speed for migration. maximum speed in bytes per second. (Since 2.8)
downtime-limit: set maximum tolerated downtime for migration. maximum downtime in milliseconds (Since 2.8)
x-checkpoint-delay: The delay time (in ms) between two COLO checkpoints in periodic mode. (Since 2.8)
block-incremental: Affects how much storage is migrated when the block migration capability is enabled. When false, the entire storage backing chain is migrated into a flattened image at the destination; when true, only the active qcow2 layer is migrated and the destination must already have access to the same backing chain as was used on the source. (since 2.10)
multifd-channels: Number of channels used to migrate data in parallel. This is the same number that the number of sockets used for migration. The default value is 2 (since 4.0)
xbzrle-cache-size: cache size to be used by XBZRLE migration. It needs to be a multiple of the target page size and a power of 2 (Since 2.11)
max-postcopy-bandwidth: Background transfer bandwidth during postcopy. Defaults to 0 (unlimited). In bytes per second. (Since 3.0)
max-cpu-throttle: maximum cpu throttle percentage. Defaults to 99. (Since 3.1)
multifd-compression: Which compression method to use. Defaults to none. (Since 5.0)
multifd-zlib-level: Set the compression level to be used in live migration, the compression level is an integer between 0 and 9, where 0 means no compression, 1 means the best compression speed, and 9 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)
multifd-zstd-level: Set the compression level to be used in live migration, the compression level is an integer between 0 and 20, where 0 means no compression, 1 means the best compression speed, and 20 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)
block-bitmap-mapping: Maps block nodes and bitmaps on them to aliases for the purpose of dirty bitmap migration. Such aliases may for example be the corresponding names on the opposite site. The mapping must be one-to-one, but not necessarily complete: On the source, unmapped bitmaps and all bitmaps on unmapped nodes will be ignored. On the destination, encountering an unmapped alias in the incoming migration stream will result in a report, and all further bitmap migration data will then be discarded. Note that the destination does not know about bitmaps it does not receive, so there is no limitation or requirement regarding the number of bitmaps received, or how they are named, or on which nodes they are placed. By default (when this parameter has never been set), bitmap names are mapped to themselves. Nodes are mapped to their block device name if there is one, and to their node name otherwise. (Since 5.2)

Since¶

2.4

`MigrateSetParameters` (Object)¶

Members¶

announce-initial: int (optional): Initial delay (in milliseconds) before sending the first announce (Since 4.0)
announce-max: int (optional): Maximum delay (in milliseconds) between packets in the announcement (Since 4.0)
announce-rounds: int (optional): Number of self-announce packets sent after migration (Since 4.0)
announce-step: int (optional): Increase in delay (in milliseconds) between subsequent packets in the announcement (Since 4.0)
compress-level: int (optional): compression level
compress-threads: int (optional): compression thread count
compress-wait-thread: boolean (optional): Controls behavior when all compression threads are currently busy. If true (default), wait for a free compression thread to become available; otherwise, send the page uncompressed. (Since 3.1)
decompress-threads: int (optional): decompression thread count
throttle-trigger-threshold: int (optional): The ratio of bytes_dirty_period and bytes_xfer_period to trigger throttling. It is expressed as percentage. The default value is 50. (Since 5.0)
cpu-throttle-initial: int (optional): Initial percentage of time guest cpus are throttled when migration auto-converge is activated. The default value is 20. (Since 2.7)
cpu-throttle-increment: int (optional): throttle percentage increase each time auto-converge detects that migration is not making progress. The default value is 10. (Since 2.7)
cpu-throttle-tailslow: boolean (optional): Make CPU throttling slower at tail stage At the tail stage of throttling, the Guest is very sensitive to CPU percentage while the cpu-throttle -increment is excessive usually at tail stage. If this parameter is true, we will compute the ideal CPU percentage used by the Guest, which may exactly make the dirty rate match the dirty rate threshold. Then we will choose a smaller throttle increment between the one specified by cpu-throttle-increment and the one generated by ideal CPU percentage. Therefore, it is compatible to traditional throttling, meanwhile the throttle increment won’t be excessive at tail stage. The default value is false. (Since 5.1)
tls-creds: StrOrNull (optional): ID of the ‘tls-creds’ object that provides credentials for establishing a TLS connection over the migration data channel. On the outgoing side of the migration, the credentials must be for a ‘client’ endpoint, while for the incoming side the credentials must be for a ‘server’ endpoint. Setting this to a non-empty string enables TLS for all migrations. An empty string means that QEMU will use plain text mode for migration, rather than TLS (Since 2.9) Previously (since 2.7), this was reported by omitting tls-creds instead.
tls-hostname: StrOrNull (optional): hostname of the target host for the migration. This is required when using x509 based TLS credentials and the migration URI does not already include a hostname. For example if using fd: or exec: based migration, the hostname must be provided so that the server’s x509 certificate identity can be validated. (Since 2.7) An empty string means that QEMU will use the hostname associated with the migration URI, if any. (Since 2.9) Previously (since 2.7), this was reported by omitting tls-hostname instead.
max-bandwidth: int (optional): to set maximum speed for migration. maximum speed in bytes per second. (Since 2.8)
downtime-limit: int (optional): set maximum tolerated downtime for migration. maximum downtime in milliseconds (Since 2.8)
x-checkpoint-delay: int (optional): the delay time between two COLO checkpoints. (Since 2.8)
block-incremental: boolean (optional): Affects how much storage is migrated when the block migration capability is enabled. When false, the entire storage backing chain is migrated into a flattened image at the destination; when true, only the active qcow2 layer is migrated and the destination must already have access to the same backing chain as was used on the source. (since 2.10)
multifd-channels: int (optional): Number of channels used to migrate data in parallel. This is the same number that the number of sockets used for migration. The default value is 2 (since 4.0)
xbzrle-cache-size: int (optional): cache size to be used by XBZRLE migration. It needs to be a multiple of the target page size and a power of 2 (Since 2.11)
max-postcopy-bandwidth: int (optional): Background transfer bandwidth during postcopy. Defaults to 0 (unlimited). In bytes per second. (Since 3.0)
max-cpu-throttle: int (optional): maximum cpu throttle percentage. The default value is 99. (Since 3.1)
multifd-compression: MultiFDCompression (optional): Which compression method to use. Defaults to none. (Since 5.0)
multifd-zlib-level: int (optional): Set the compression level to be used in live migration, the compression level is an integer between 0 and 9, where 0 means no compression, 1 means the best compression speed, and 9 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)
multifd-zstd-level: int (optional): Set the compression level to be used in live migration, the compression level is an integer between 0 and 20, where 0 means no compression, 1 means the best compression speed, and 20 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)
block-bitmap-mapping: array of BitmapMigrationNodeAlias (optional): Maps block nodes and bitmaps on them to aliases for the purpose of dirty bitmap migration. Such aliases may for example be the corresponding names on the opposite site. The mapping must be one-to-one, but not necessarily complete: On the source, unmapped bitmaps and all bitmaps on unmapped nodes will be ignored. On the destination, encountering an unmapped alias in the incoming migration stream will result in a report, and all further bitmap migration data will then be discarded. Note that the destination does not know about bitmaps it does not receive, so there is no limitation or requirement regarding the number of bitmaps received, or how they are named, or on which nodes they are placed. By default (when this parameter has never been set), bitmap names are mapped to themselves. Nodes are mapped to their block device name if there is one, and to their node name otherwise. (Since 5.2)
tls-authz: StrOrNull (optional): Not documented

Since¶

2.4

`migrate-set-parameters` (Command)¶

Set various migration parameters.

Arguments¶

The members of MigrateSetParameters

Since¶

2.4

Example¶

-> { "execute": "migrate-set-parameters" ,
     "arguments": { "compress-level": 1 } }

`MigrationParameters` (Object)¶

The optional members aren’t actually optional.

Members¶

announce-initial: int (optional): Initial delay (in milliseconds) before sending the first announce (Since 4.0)
announce-max: int (optional): Maximum delay (in milliseconds) between packets in the announcement (Since 4.0)
announce-rounds: int (optional): Number of self-announce packets sent after migration (Since 4.0)
announce-step: int (optional): Increase in delay (in milliseconds) between subsequent packets in the announcement (Since 4.0)
compress-level: int (optional): compression level
compress-threads: int (optional): compression thread count
compress-wait-thread: boolean (optional): Controls behavior when all compression threads are currently busy. If true (default), wait for a free compression thread to become available; otherwise, send the page uncompressed. (Since 3.1)
decompress-threads: int (optional): decompression thread count
throttle-trigger-threshold: int (optional): The ratio of bytes_dirty_period and bytes_xfer_period to trigger throttling. It is expressed as percentage. The default value is 50. (Since 5.0)
cpu-throttle-initial: int (optional): Initial percentage of time guest cpus are throttled when migration auto-converge is activated. (Since 2.7)
cpu-throttle-increment: int (optional): throttle percentage increase each time auto-converge detects that migration is not making progress. (Since 2.7)
cpu-throttle-tailslow: boolean (optional): Make CPU throttling slower at tail stage At the tail stage of throttling, the Guest is very sensitive to CPU percentage while the cpu-throttle -increment is excessive usually at tail stage. If this parameter is true, we will compute the ideal CPU percentage used by the Guest, which may exactly make the dirty rate match the dirty rate threshold. Then we will choose a smaller throttle increment between the one specified by cpu-throttle-increment and the one generated by ideal CPU percentage. Therefore, it is compatible to traditional throttling, meanwhile the throttle increment won’t be excessive at tail stage. The default value is false. (Since 5.1)
tls-creds: string (optional): ID of the ‘tls-creds’ object that provides credentials for establishing a TLS connection over the migration data channel. On the outgoing side of the migration, the credentials must be for a ‘client’ endpoint, while for the incoming side the credentials must be for a ‘server’ endpoint. An empty string means that QEMU will use plain text mode for migration, rather than TLS (Since 2.7) Note: 2.8 reports this by omitting tls-creds instead.
tls-hostname: string (optional): hostname of the target host for the migration. This is required when using x509 based TLS credentials and the migration URI does not already include a hostname. For example if using fd: or exec: based migration, the hostname must be provided so that the server’s x509 certificate identity can be validated. (Since 2.7) An empty string means that QEMU will use the hostname associated with the migration URI, if any. (Since 2.9) Note: 2.8 reports this by omitting tls-hostname instead.
tls-authz: string (optional): ID of the ‘authz’ object subclass that provides access control checking of the TLS x509 certificate distinguished name. (Since 4.0)
max-bandwidth: int (optional): to set maximum speed for migration. maximum speed in bytes per second. (Since 2.8)
downtime-limit: int (optional): set maximum tolerated downtime for migration. maximum downtime in milliseconds (Since 2.8)
x-checkpoint-delay: int (optional): the delay time between two COLO checkpoints. (Since 2.8)
block-incremental: boolean (optional): Affects how much storage is migrated when the block migration capability is enabled. When false, the entire storage backing chain is migrated into a flattened image at the destination; when true, only the active qcow2 layer is migrated and the destination must already have access to the same backing chain as was used on the source. (since 2.10)
multifd-channels: int (optional): Number of channels used to migrate data in parallel. This is the same number that the number of sockets used for migration. The default value is 2 (since 4.0)
xbzrle-cache-size: int (optional): cache size to be used by XBZRLE migration. It needs to be a multiple of the target page size and a power of 2 (Since 2.11)
max-postcopy-bandwidth: int (optional): Background transfer bandwidth during postcopy. Defaults to 0 (unlimited). In bytes per second. (Since 3.0)
max-cpu-throttle: int (optional): maximum cpu throttle percentage. Defaults to 99. (Since 3.1)
multifd-compression: MultiFDCompression (optional): Which compression method to use. Defaults to none. (Since 5.0)
multifd-zlib-level: int (optional): Set the compression level to be used in live migration, the compression level is an integer between 0 and 9, where 0 means no compression, 1 means the best compression speed, and 9 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)
multifd-zstd-level: int (optional): Set the compression level to be used in live migration, the compression level is an integer between 0 and 20, where 0 means no compression, 1 means the best compression speed, and 20 means best compression ratio which will consume more CPU. Defaults to 1. (Since 5.0)
block-bitmap-mapping: array of BitmapMigrationNodeAlias (optional): Maps block nodes and bitmaps on them to aliases for the purpose of dirty bitmap migration. Such aliases may for example be the corresponding names on the opposite site. The mapping must be one-to-one, but not necessarily complete: On the source, unmapped bitmaps and all bitmaps on unmapped nodes will be ignored. On the destination, encountering an unmapped alias in the incoming migration stream will result in a report, and all further bitmap migration data will then be discarded. Note that the destination does not know about bitmaps it does not receive, so there is no limitation or requirement regarding the number of bitmaps received, or how they are named, or on which nodes they are placed. By default (when this parameter has never been set), bitmap names are mapped to themselves. Nodes are mapped to their block device name if there is one, and to their node name otherwise. (Since 5.2)

Since¶

2.4

`query-migrate-parameters` (Command)¶

Returns information about the current migration parameters

Returns¶

MigrationParameters

Since¶

2.4

Example¶

-> { "execute": "query-migrate-parameters" }
<- { "return": {
         "decompress-threads": 2,
         "cpu-throttle-increment": 10,
         "compress-threads": 8,
         "compress-level": 1,
         "cpu-throttle-initial": 20,
         "max-bandwidth": 33554432,
         "downtime-limit": 300
      }
   }

`client_migrate_info` (Command)¶

Set migration information for remote display. This makes the server ask the client to automatically reconnect using the new parameters once migration finished successfully. Only implemented for SPICE.

Arguments¶

protocol: string: must be “spice”
hostname: string: migration target hostname
port: int (optional): spice tcp port for plaintext channels
tls-port: int (optional): spice tcp port for tls-secured channels
cert-subject: string (optional): server certificate subject

Since¶

0.14

Example¶

-> { "execute": "client_migrate_info",
     "arguments": { "protocol": "spice",
                    "hostname": "virt42.lab.kraxel.org",
                    "port": 1234 } }
<- { "return": {} }

`migrate-start-postcopy` (Command)¶

Followup to a migration command to switch the migration to postcopy mode. The postcopy-ram capability must be set on both source and destination before the original migration command.

Since¶

2.5

Example¶

-> { "execute": "migrate-start-postcopy" }
<- { "return": {} }

`MIGRATION` (Event)¶

Emitted when a migration event happens

Arguments¶

status: MigrationStatus: MigrationStatus describing the current migration status.

Since¶

2.4

Example¶

<- {"timestamp": {"seconds": 1432121972, "microseconds": 744001},
    "event": "MIGRATION",
    "data": {"status": "completed"} }

`MIGRATION_PASS` (Event)¶

Emitted from the source side of a migration at the start of each pass (when it syncs the dirty bitmap)

Arguments¶

pass: int: An incrementing count (starting at 1 on the first pass)

Since¶

2.6

Example¶

{ "timestamp": {"seconds": 1449669631, "microseconds": 239225},
  "event": "MIGRATION_PASS", "data": {"pass": 2} }

`COLOMessage` (Enum)¶

The message transmission between Primary side and Secondary side.

Values¶

checkpoint-ready: Secondary VM (SVM) is ready for checkpointing
checkpoint-request: Primary VM (PVM) tells SVM to prepare for checkpointing
checkpoint-reply: SVM gets PVM’s checkpoint request
vmstate-send: VM’s state will be sent by PVM.
vmstate-size: The total size of VMstate.
vmstate-received: VM’s state has been received by SVM.
vmstate-loaded: VM’s state has been loaded by SVM.

Since¶

2.8

`COLOMode` (Enum)¶

The COLO current mode.

Values¶

none: COLO is disabled.
primary: COLO node in primary side.
secondary: COLO node in slave side.

Since¶

2.8

`FailoverStatus` (Enum)¶

An enumeration of COLO failover status

Values¶

none: no failover has ever happened
require: got failover requirement but not handled
active: in the process of doing failover
completed: finish the process of failover
relaunch: restart the failover process, from ‘none’ -> ‘completed’ (Since 2.9)

Since¶

2.8

`COLO_EXIT` (Event)¶

Emitted when VM finishes COLO mode due to some errors happening or at the request of users.

Arguments¶

mode: COLOMode: report COLO mode when COLO exited.
reason: COLOExitReason: describes the reason for the COLO exit.

Since¶

3.1

Example¶

<- { "timestamp": {"seconds": 2032141960, "microseconds": 417172},
     "event": "COLO_EXIT", "data": {"mode": "primary", "reason": "request" } }

`COLOExitReason` (Enum)¶

The reason for a COLO exit.

Values¶

none: failover has never happened. This state does not occur in the COLO_EXIT event, and is only visible in the result of query-colo-status.
request: COLO exit is due to an external request.
error: COLO exit is due to an internal error.
processing: COLO is currently handling a failover (since 4.0).

Since¶

3.1

`x-colo-lost-heartbeat` (Command)¶

Tell qemu that heartbeat is lost, request it to do takeover procedures. If this command is sent to the PVM, the Primary side will exit COLO mode. If sent to the Secondary, the Secondary side will run failover work, then takes over server operation to become the service VM.

Since¶

2.8

Example¶

-> { "execute": "x-colo-lost-heartbeat" }
<- { "return": {} }

`migrate_cancel` (Command)¶

Cancel the current executing migration process.

Returns¶

nothing on success

Notes¶

This command succeeds even if there is no migration process running.

Since¶

0.14

Example¶

-> { "execute": "migrate_cancel" }
<- { "return": {} }

`migrate-continue` (Command)¶

Continue migration when it’s in a paused state.

Arguments¶

state: MigrationStatus: The state the migration is currently expected to be in

Returns¶

nothing on success

Since¶

2.11

Example¶

-> { "execute": "migrate-continue" , "arguments":
     { "state": "pre-switchover" } }
<- { "return": {} }

`migrate` (Command)¶

Migrates the current running guest to another Virtual Machine.

Arguments¶

uri: string: the Uniform Resource Identifier of the destination VM
blk: boolean (optional): do block migration (full disk copy)
inc: boolean (optional): incremental disk copy migration
detach: boolean (optional): this argument exists only for compatibility reasons and is ignored by QEMU
resume: boolean (optional): resume one paused migration, default “off”. (since 3.0)

Returns¶

nothing on success

Since¶

0.14

Notes¶

The ‘query-migrate’ command should be used to check migration’s progress and final result (this information is provided by the ‘status’ member)
All boolean arguments default to false
The user Monitor’s “detach” argument is invalid in QMP and should not be used

Example¶

-> { "execute": "migrate", "arguments": { "uri": "tcp:0:4446" } }
<- { "return": {} }

`migrate-incoming` (Command)¶

Start an incoming migration, the qemu must have been started with -incoming defer

Arguments¶

uri: string: The Uniform Resource Identifier identifying the source or address to listen on

Returns¶

nothing on success

Since¶

2.3

Notes¶

It’s a bad idea to use a string for the uri, but it needs to stay compatible with -incoming and the format of the uri is already exposed above libvirt.
QEMU must be started with -incoming defer to allow migrate-incoming to be used.
The uri format is the same as for -incoming

Example¶

-> { "execute": "migrate-incoming",
     "arguments": { "uri": "tcp::4446" } }
<- { "return": {} }

`xen-save-devices-state` (Command)¶

Save the state of all devices to file. The RAM and the block devices of the VM are not saved by this command.

Arguments¶

filename: string: the file to save the state of the devices to as binary data. See xen-save-devices-state.txt for a description of the binary format.
live: boolean (optional): Optional argument to ask QEMU to treat this command as part of a live migration. Default to true. (since 2.11)

Returns¶

Nothing on success

Since¶

1.1

Example¶

-> { "execute": "xen-save-devices-state",
     "arguments": { "filename": "/tmp/save" } }
<- { "return": {} }

`xen-set-global-dirty-log` (Command)¶

Enable or disable the global dirty log mode.

Arguments¶

enable: boolean: true to enable, false to disable.

Returns¶

nothing

Since¶

1.3

Example¶

-> { "execute": "xen-set-global-dirty-log",
     "arguments": { "enable": true } }
<- { "return": {} }

`xen-load-devices-state` (Command)¶

Load the state of all devices from file. The RAM and the block devices of the VM are not loaded by this command.

Arguments¶

filename: string: the file to load the state of the devices from as binary data. See xen-save-devices-state.txt for a description of the binary format.

Since¶

2.7

Example¶

-> { "execute": "xen-load-devices-state",
     "arguments": { "filename": "/tmp/resume" } }
<- { "return": {} }

`xen-set-replication` (Command)¶

Enable or disable replication.

Arguments¶

enable: boolean: true to enable, false to disable.
primary: boolean: true for primary or false for secondary.
failover: boolean (optional): true to do failover, false to stop. but cannot be specified if ‘enable’ is true. default value is false.

Returns¶

nothing.

Example¶

-> { "execute": "xen-set-replication",
     "arguments": {"enable": true, "primary": false} }
<- { "return": {} }

Since¶

2.9

If¶

defined(CONFIG_REPLICATION)

`ReplicationStatus` (Object)¶

The result format for ‘query-xen-replication-status’.

Members¶

error: boolean: true if an error happened, false if replication is normal.
desc: string (optional): the human readable error description string, when error is ‘true’.

Arguments¶

uri: string: the URI to be used for the recovery of migration stream.

Returns¶

nothing.

Example¶

-> { "execute": "migrate-recover",
     "arguments": { "uri": "tcp:192.168.1.200:12345" } }
<- { "return": {} }

Since¶

3.0

`migrate-pause` (Command)¶

Pause a migration. Currently it only supports postcopy.

Returns¶

nothing.

Example¶

-> { "execute": "migrate-pause" }
<- { "return": {} }

Since¶

3.0

`UNPLUG_PRIMARY` (Event)¶

Emitted from source side of a migration when migration state is WAIT_UNPLUG. Device was unplugged by guest operating system. Device resources in QEMU are kept on standby to be able to re-plug it in case of migration failure.

Arguments¶

device-id: string: QEMU device id of the unplugged device

Since¶

4.2

Example¶

{"event": "UNPLUG_PRIMARY", "data": {"device-id": "hostdev0"} }

`DirtyRateStatus` (Enum)¶

An enumeration of dirtyrate status.

Values¶

unstarted: the dirtyrate thread has not been started.
measuring: the dirtyrate thread is measuring.
measured: the dirtyrate thread has measured and results are available.

Since¶

5.2

`DirtyRateInfo` (Object)¶

Information about current dirty page rate of vm.

Members¶

dirty-rate: int (optional): an estimate of the dirty page rate of the VM in units of MB/s, present only when estimating the rate has completed.
status: DirtyRateStatus: status containing dirtyrate query status includes ‘unstarted’ or ‘measuring’ or ‘measured’
start-time: int: start time in units of second for calculation
calc-time: int: time in units of second for sample dirty pages

Since¶

5.2

`calc-dirty-rate` (Command)¶

start calculating dirty page rate for vm

Arguments¶

calc-time: int: time in units of second for sample dirty pages

Since¶

5.2

Example¶

{"command": "calc-dirty-rate", "data": {"calc-time": 1} }

`query-dirty-rate` (Command)¶

query dirty page rate in units of MB/s for vm

Since¶

5.2

`snapshot-save` (Command)¶

Save a VM snapshot

Arguments¶

job-id: string: identifier for the newly created job
tag: string: name of the snapshot to create
vmstate: string: block device node name to save vmstate to
devices: array of string: list of block device node names to save a snapshot to

Applications should not assume that the snapshot save is complete when this command returns. The job commands / events must be used to determine completion and to fetch details of any errors that arise.

Note that execution of the guest CPUs may be stopped during the time it takes to save the snapshot. A future version of QEMU may ensure CPUs are executing continuously.

It is strongly recommended that devices contain all writable block device nodes if a consistent snapshot is required.

If tag already exists, an error will be reported

Returns¶

nothing

Example¶

-> { "execute": "snapshot-save",
     "data": {
        "job-id": "snapsave0",
        "tag": "my-snap",
        "vmstate": "disk0",
        "devices": ["disk0", "disk1"]
     }
   }
<- { "return": { } }
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "created", "id": "snapsave0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "running", "id": "snapsave0"}}
<- {"event": "STOP"}
<- {"event": "RESUME"}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "waiting", "id": "snapsave0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "pending", "id": "snapsave0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "concluded", "id": "snapsave0"}}
-> {"execute": "query-jobs"}
<- {"return": [{"current-progress": 1,
                "status": "concluded",
                "total-progress": 1,
                "type": "snapshot-save",
                "id": "snapsave0"}]}

Since¶

6.0

`snapshot-load` (Command)¶

Load a VM snapshot

Arguments¶

job-id: string: identifier for the newly created job
tag: string: name of the snapshot to load.
vmstate: string: block device node name to load vmstate from
devices: array of string: list of block device node names to load a snapshot from

Applications should not assume that the snapshot load is complete when this command returns. The job commands / events must be used to determine completion and to fetch details of any errors that arise.

Note that execution of the guest CPUs will be stopped during the time it takes to load the snapshot.

It is strongly recommended that devices contain all writable block device nodes that can have changed since the original snapshot-save command execution.

Returns¶

nothing

Example¶

-> { "execute": "snapshot-load",
     "data": {
        "job-id": "snapload0",
        "tag": "my-snap",
        "vmstate": "disk0",
        "devices": ["disk0", "disk1"]
     }
   }
<- { "return": { } }
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "created", "id": "snapload0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "running", "id": "snapload0"}}
<- {"event": "STOP"}
<- {"event": "RESUME"}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "waiting", "id": "snapload0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "pending", "id": "snapload0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "concluded", "id": "snapload0"}}
-> {"execute": "query-jobs"}
<- {"return": [{"current-progress": 1,
                "status": "concluded",
                "total-progress": 1,
                "type": "snapshot-load",
                "id": "snapload0"}]}

Since¶

6.0

`snapshot-delete` (Command)¶

Delete a VM snapshot

Arguments¶

job-id: string: identifier for the newly created job
tag: string: name of the snapshot to delete.
devices: array of string: list of block device node names to delete a snapshot from

Applications should not assume that the snapshot delete is complete when this command returns. The job commands / events must be used to determine completion and to fetch details of any errors that arise.

Returns¶

nothing

Example¶

-> { "execute": "snapshot-delete",
     "data": {
        "job-id": "snapdelete0",
        "tag": "my-snap",
        "devices": ["disk0", "disk1"]
     }
   }
<- { "return": { } }
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "created", "id": "snapdelete0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "running", "id": "snapdelete0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "waiting", "id": "snapdelete0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "pending", "id": "snapdelete0"}}
<- {"event": "JOB_STATUS_CHANGE",
    "data": {"status": "concluded", "id": "snapdelete0"}}
-> {"execute": "query-jobs"}
<- {"return": [{"current-progress": 1,
                "status": "concluded",
                "total-progress": 1,
                "type": "snapshot-delete",
                "id": "snapdelete0"}]}

Since¶

6.0

Transactions¶

`Abort` (Object)¶

This action can be used to test transaction failure.

Since¶

1.6

`ActionCompletionMode` (Enum)¶

An enumeration of Transactional completion modes.

Values¶

individual: Do not attempt to cancel any other Actions if any Actions fail after the Transaction request succeeds. All Actions that can complete successfully will do so without waiting on others. This is the default.
grouped: If any Action fails after the Transaction succeeds, cancel all Actions. Actions do not complete until all Actions are ready to complete. May be rejected by Actions that do not support this completion mode.

Since¶

2.5

`TransactionAction` (Object)¶

A discriminated record of operations that can be performed with transaction. Action type can be:

abort: since 1.6
block-dirty-bitmap-add: since 2.5
block-dirty-bitmap-remove: since 4.2
block-dirty-bitmap-clear: since 2.5
block-dirty-bitmap-enable: since 4.0
block-dirty-bitmap-disable: since 4.0
block-dirty-bitmap-merge: since 4.0
blockdev-backup: since 2.3
blockdev-snapshot: since 2.5
blockdev-snapshot-internal-sync: since 1.7
blockdev-snapshot-sync: since 1.1
drive-backup: since 1.6

Members¶

type: One of abort, block-dirty-bitmap-add, block-dirty-bitmap-remove, block-dirty-bitmap-clear, block-dirty-bitmap-enable, block-dirty-bitmap-disable, block-dirty-bitmap-merge, blockdev-backup, blockdev-snapshot, blockdev-snapshot-internal-sync, blockdev-snapshot-sync, drive-backup
data: Abort when type is "abort"
data: BlockDirtyBitmapAdd when type is "block-dirty-bitmap-add"
data: BlockDirtyBitmap when type is "block-dirty-bitmap-remove"
data: BlockDirtyBitmap when type is "block-dirty-bitmap-clear"
data: BlockDirtyBitmap when type is "block-dirty-bitmap-enable"
data: BlockDirtyBitmap when type is "block-dirty-bitmap-disable"
data: BlockDirtyBitmapMerge when type is "block-dirty-bitmap-merge"
data: BlockdevBackup when type is "blockdev-backup"
data: BlockdevSnapshot when type is "blockdev-snapshot"
data: BlockdevSnapshotInternal when type is "blockdev-snapshot-internal-sync"
data: BlockdevSnapshotSync when type is "blockdev-snapshot-sync"
data: DriveBackup when type is "drive-backup"

Since¶

1.1

`TransactionProperties` (Object)¶

Optional arguments to modify the behavior of a Transaction.

Members¶

completion-mode: ActionCompletionMode (optional): Controls how jobs launched asynchronously by Actions will complete or fail as a group. See ActionCompletionMode for details.

Since¶

2.5

`transaction` (Command)¶

Executes a number of transactionable QMP commands atomically. If any operation fails, then the entire set of actions will be abandoned and the appropriate error returned.

For external snapshots, the dictionary contains the device, the file to use for the new snapshot, and the format. The default format, if not specified, is qcow2.

Each new snapshot defaults to being created by QEMU (wiping any contents if the file already exists), but it is also possible to reuse an externally-created file. In the latter case, you should ensure that the new image file has the same contents as the current one; QEMU cannot perform any meaningful check. Typically this is achieved by using the current image file as the backing file for the new image.

On failure, the original disks pre-snapshot attempt will be used.

For internal snapshots, the dictionary contains the device and the snapshot’s name. If an internal snapshot matching name already exists, the request will be rejected. Only some image formats support it, for example, qcow2, and rbd,

On failure, qemu will try delete the newly created internal snapshot in the transaction. When an I/O error occurs during deletion, the user needs to fix it later with qemu-img or other command.

Arguments¶

actions: array of TransactionAction: List of TransactionAction; information needed for the respective operations.
properties: TransactionProperties (optional): structure of additional options to control the execution of the transaction. See TransactionProperties for additional detail.

Returns¶

nothing on success

Errors depend on the operations of the transaction

Note¶

The transaction aborts on the first failure. Therefore, there will be information on only one failed operation returned in an error condition, and subsequent actions will not have been attempted.

Since¶

1.1

Example¶

-> { "execute": "transaction",
     "arguments": { "actions": [
         { "type": "blockdev-snapshot-sync", "data" : { "device": "ide-hd0",
                                     "snapshot-file": "/some/place/my-image",
                                     "format": "qcow2" } },
         { "type": "blockdev-snapshot-sync", "data" : { "node-name": "myfile",
                                     "snapshot-file": "/some/place/my-image2",
                                     "snapshot-node-name": "node3432",
                                     "mode": "existing",
                                     "format": "qcow2" } },
         { "type": "blockdev-snapshot-sync", "data" : { "device": "ide-hd1",
                                     "snapshot-file": "/some/place/my-image2",
                                     "mode": "existing",
                                     "format": "qcow2" } },
         { "type": "blockdev-snapshot-internal-sync", "data" : {
                                     "device": "ide-hd2",
                                     "name": "snapshot0" } } ] } }
<- { "return": {} }

Tracing¶

`TraceEventState` (Enum)¶

State of a tracing event.

Values¶

unavailable: The event is statically disabled.
disabled: The event is dynamically disabled.
enabled: The event is dynamically enabled.

Since¶

2.2

`TraceEventInfo` (Object)¶

Information of a tracing event.

Members¶

name: string: Event name.
state: TraceEventState: Tracing state.
vcpu: boolean: Whether this is a per-vCPU event (since 2.7).

An event is per-vCPU if it has the “vcpu” property in the “trace-events” files.

Since¶

2.2

`trace-event-get-state` (Command)¶

Query the state of events.

Arguments¶

name: string: Event name pattern (case-sensitive glob).
vcpu: int (optional): The vCPU to query (any by default; since 2.7).

Returns¶

a list of TraceEventInfo for the matching events

An event is returned if:

its name matches the name pattern, and
if vcpu is given, the event has the “vcpu” property.

Therefore, if vcpu is given, the operation will only match per-vCPU events, returning their state on the specified vCPU. Special case: if name is an exact match, vcpu is given and the event does not have the “vcpu” property, an error is returned.

Since¶

2.2

Example¶

-> { "execute": "trace-event-get-state",
     "arguments": { "name": "qemu_memalign" } }
<- { "return": [ { "name": "qemu_memalign", "state": "disabled" } ] }

`trace-event-set-state` (Command)¶

Set the dynamic tracing state of events.

Arguments¶

name: string: Event name pattern (case-sensitive glob).
enable: boolean: Whether to enable tracing.
ignore-unavailable: boolean (optional): Do not match unavailable events with name.
vcpu: int (optional): The vCPU to act upon (all by default; since 2.7).

An event’s state is modified if: - its name matches the name pattern, and - if vcpu is given, the event has the “vcpu” property.

Therefore, if vcpu is given, the operation will only match per-vCPU events, setting their state on the specified vCPU. Special case: if name is an exact match, vcpu is given and the event does not have the “vcpu” property, an error is returned.

Since¶

2.2

Example¶

-> { "execute": "trace-event-set-state",
     "arguments": { "name": "qemu_memalign", "enable": "true" } }
<- { "return": {} }

Compatibility policy¶

`CompatPolicyInput` (Enum)¶

Policy for handling “funny” input.

Values¶

accept: Accept silently
reject: Reject with an error
crash: abort() the process

Since¶

6.0

`CompatPolicyOutput` (Enum)¶

Policy for handling “funny” output.

Values¶

accept: Pass on unchanged
hide: Filter out

Since¶

6.0

`CompatPolicy` (Object)¶

Policy for handling deprecated management interfaces.

This is intended for testing users of the management interfaces.

Limitation: covers only syntactic aspects of QMP, i.e. stuff tagged with feature ‘deprecated’. We may want to extend it to cover semantic aspects, CLI, and experimental features.

Members¶

deprecated-input: CompatPolicyInput (optional): how to handle deprecated input (default ‘accept’)
deprecated-output: CompatPolicyOutput (optional): how to handle deprecated output (default ‘accept’)

Since¶

6.0

QMP monitor control¶

`qmp_capabilities` (Command)¶

Enable QMP capabilities.

Arguments:

Arguments¶

enable: array of QMPCapability (optional): An optional list of QMPCapability values to enable. The client must not enable any capability that is not mentioned in the QMP greeting message. If the field is not provided, it means no QMP capabilities will be enabled. (since 2.12)

Example¶

-> { "execute": "qmp_capabilities",
     "arguments": { "enable": [ "oob" ] } }
<- { "return": {} }

Notes¶

This command is valid exactly when first connecting: it must be issued before any other command will be accepted, and will fail once the monitor is accepting other commands. (see qemu docs/interop/qmp-spec.txt)

The QMP client needs to explicitly enable QMP capabilities, otherwise all the QMP capabilities will be turned off by default.

Since¶

0.13

`QMPCapability` (Enum)¶

Enumeration of capabilities to be advertised during initial client connection, used for agreeing on particular QMP extension behaviors.

Values¶

oob: QMP ability to support out-of-band requests. (Please refer to qmp-spec.txt for more information on OOB)

Since¶

2.12

`VersionTriple` (Object)¶

A three-part version number.

Members¶

major: int: The major version number.
minor: int: The minor version number.
micro: int: The micro version number.

Since¶

2.4

`VersionInfo` (Object)¶

A description of QEMU’s version.

Members¶

qemu: VersionTriple: The version of QEMU. By current convention, a micro version of 50 signifies a development branch. A micro version greater than or equal to 90 signifies a release candidate for the next minor version. A micro version of less than 50 signifies a stable release.
package: string: QEMU will always set this field to an empty string. Downstream versions of QEMU should set this to a non-empty string. The exact format depends on the downstream however it highly recommended that a unique name is used.

Since¶

0.14

`query-version` (Command)¶

Returns the current version of QEMU.

Returns¶

A VersionInfo object describing the current version of QEMU.

Since¶

0.14

Example¶

-> { "execute": "query-version" }
<- {
      "return":{
         "qemu":{
            "major":0,
            "minor":11,
            "micro":5
         },
         "package":""
      }
   }

`CommandInfo` (Object)¶

Information about a QMP command

Members¶

name: string: The command name

Since¶

0.14

`query-commands` (Command)¶

Return a list of supported QMP commands by this server

Returns¶

A list of CommandInfo for all supported commands

Since¶

0.14

Example¶

-> { "execute": "query-commands" }
<- {
     "return":[
        {
           "name":"query-balloon"
        },
        {
           "name":"system_powerdown"
        }
     ]
   }

Note¶

This example has been shortened as the real response is too long.

`quit` (Command)¶

This command will cause the QEMU process to exit gracefully. While every attempt is made to send the QMP response before terminating, this is not guaranteed. When using this interface, a premature EOF would not be unexpected.

Since¶

0.14

Example¶

-> { "execute": "quit" }
<- { "return": {} }

`MonitorMode` (Enum)¶

An enumeration of monitor modes.

Values¶

readline: HMP monitor (human-oriented command line interface)
control: QMP monitor (JSON-based machine interface)

Since¶

5.0

`MonitorOptions` (Object)¶

Options to be used for adding a new monitor.

Members¶

id: string (optional): Name of the monitor
mode: MonitorMode (optional): Selects the monitor mode (default: readline in the system emulator, control in qemu-storage-daemon)
pretty: boolean (optional): Enables pretty printing (QMP only)
chardev: string: Name of a character device to expose the monitor on

Since¶

5.0

QMP introspection¶

`query-qmp-schema` (Command)¶

Command query-qmp-schema exposes the QMP wire ABI as an array of SchemaInfo. This lets QMP clients figure out what commands and events are available in this QEMU, and their parameters and results.

However, the SchemaInfo can’t reflect all the rules and restrictions that apply to QMP. It’s interface introspection (figuring out what’s there), not interface specification. The specification is in the QAPI schema.

Furthermore, while we strive to keep the QMP wire format backwards-compatible across qemu versions, the introspection output is not guaranteed to have the same stability. For example, one version of qemu may list an object member as an optional non-variant, while another lists the same member only through the object’s variants; or the type of a member may change from a generic string into a specific enum or from one specific type into an alternate that includes the original type alongside something else.

Returns¶

array of SchemaInfo, where each element describes an entity in the ABI: command, event, type, …

The order of the various SchemaInfo is unspecified; however, all names are guaranteed to be unique (no name will be duplicated with different meta-types).

Note¶

the QAPI schema is also used to help define internal interfaces, by defining QAPI types. These are not part of the QMP wire ABI, and therefore not returned by this command.

Since¶

2.5

`SchemaMetaType` (Enum)¶

This is a SchemaInfo’s meta type, i.e. the kind of entity it describes.

Values¶

builtin: a predefined type such as ‘int’ or ‘bool’.
enum: an enumeration type
array: an array type
object: an object type (struct or union)
alternate: an alternate type
command: a QMP command
event: a QMP event

Since¶

2.5

`SchemaInfo` (Object)¶

Members¶

name: string: the entity’s name, inherited from base. The SchemaInfo is always referenced by this name. Commands and events have the name defined in the QAPI schema. Unlike command and event names, type names are not part of the wire ABI. Consequently, type names are meaningless strings here, although they are still guaranteed unique regardless of meta-type.
meta-type: SchemaMetaType: the entity’s meta type, inherited from base.
features: array of string (optional): names of features associated with the entity, in no particular order. (since 4.1 for object types, 4.2 for commands, 5.0 for the rest)
The members of SchemaInfoBuiltin when meta-type is "builtin"
The members of SchemaInfoEnum when meta-type is "enum"
The members of SchemaInfoArray when meta-type is "array"
The members of SchemaInfoObject when meta-type is "object"
The members of SchemaInfoAlternate when meta-type is "alternate"
The members of SchemaInfoCommand when meta-type is "command"
The members of SchemaInfoEvent when meta-type is "event"

values: array of string: the enumeration type’s values, in no particular order.

Values of this type are JSON string on the wire.

Since¶

2.5

`SchemaInfoArray` (Object)¶

Additional SchemaInfo members for meta-type ‘array’.

Members¶

element-type: string: the array type’s element type.

Values of this type are JSON array on the wire.

Since¶

2.5

`SchemaInfoObject` (Object)¶

Additional SchemaInfo members for meta-type ‘object’.

Members¶

members: array of SchemaInfoObjectMember: the object type’s (non-variant) members, in no particular order.
tag: string (optional): the name of the member serving as type tag. An element of members with this name must exist.
variants: array of SchemaInfoObjectVariant (optional): variant members, i.e. additional members that depend on the type tag’s value. Present exactly when tag is present. The variants are in no particular order, and may even differ from the order of the values of the enum type of the tag.

members: array of SchemaInfoAlternateMember: the alternate type’s members, in no particular order. The members’ wire encoding is distinct, see docs/devel/qapi-code-gen.txt section Alternate types.

`ObjectPropertyInfo` (Object)¶

Members¶

name: string

the name of the property

type: string

the type of the property. This will typically come in one of four forms:

A primitive type such as ‘u8’, ‘u16’, ‘bool’, ‘str’, or ‘double’. These types are mapped to the appropriate JSON type.
A child type in the form ‘child<subtype>’ where subtype is a qdev device type name. Child properties create the composition tree.
A link type in the form ‘link<subtype>’ where subtype is a qdev device type name. Link properties form the device model graph.

description: string (optional)

if specified, the description of the property.

default-value: value (optional)

the default value, if any (since 5.0)

Since¶

1.2

`qom-list` (Command)¶

This command will list any properties of a object given a path in the object model.

Arguments¶

path: string: the path within the object model. See qom-get for a description of this parameter.

Returns¶

a list of ObjectPropertyInfo that describe the properties of the object.

Since¶

1.2

Example¶

-> { "execute": "qom-list",
     "arguments": { "path": "/chardevs" } }
<- { "return": [ { "name": "type", "type": "string" },
                 { "name": "parallel0", "type": "child<chardev-vc>" },
                 { "name": "serial0", "type": "child<chardev-vc>" },
                 { "name": "mon0", "type": "child<chardev-stdio>" } ] }

`qom-get` (Command)¶

This command will get a property from a object model path and return the value.

Arguments¶

path: string

The path within the object model. There are two forms of supported paths–absolute and partial paths.

Absolute paths are derived from the root object and can follow child<> or link<> properties. Since they can follow link<> properties, they can be arbitrarily long. Absolute paths look like absolute filenames and are prefixed with a leading slash.

Partial paths look like relative filenames. They do not begin with a prefix. The matching rules for partial paths are subtle but designed to make specifying objects easy. At each level of the composition tree, the partial path is matched as an absolute path. The first match is not returned. At least two matches are searched for. A successful result is only returned if only one match is found. If more than one match is found, a flag is return to indicate that the match was ambiguous.

property: string

The property name to read

Returns¶

The property value. The type depends on the property type. child<> and link<> properties are returned as #str pathnames. All integer property types (u8, u16, etc) are returned as #int.

Since¶

1.2

Example¶

1. Use absolute path

-> { "execute": "qom-get",
     "arguments": { "path": "/machine/unattached/device[0]",
                    "property": "hotplugged" } }
<- { "return": false }

2. Use partial path

-> { "execute": "qom-get",
     "arguments": { "path": "unattached/sysbus",
                    "property": "type" } }
<- { "return": "System" }

`qom-set` (Command)¶

This command will set a property from a object model path.

Arguments¶

path: string: see qom-get for a description of this parameter
property: string: the property name to set
value: value: a value who’s type is appropriate for the property type. See qom-get for a description of type mapping.

Since¶

1.2

Example¶

-> { "execute": "qom-set",
     "arguments": { "path": "/machine",
                    "property": "graphics",
                    "value": false } }
<- { "return": {} }

`ObjectTypeInfo` (Object)¶

This structure describes a search result from qom-list-types

Members¶

name: string: the type name found in the search
abstract: boolean (optional): the type is abstract and can’t be directly instantiated. Omitted if false. (since 2.10)
parent: string (optional): Name of parent type, if any (since 2.10)

Since¶

1.1

`qom-list-types` (Command)¶

This command will return a list of types given search parameters

Arguments¶

implements: string (optional): if specified, only return types that implement this type name
abstract: boolean (optional): if true, include abstract types in the results

Returns¶

a list of ObjectTypeInfo or an empty list if no results are found

Since¶

1.1

`qom-list-properties` (Command)¶

List properties associated with a QOM object.

Arguments¶

typename: string: the type name of an object

Note¶

objects can create properties at runtime, for example to describe links between different devices and/or objects. These properties are not included in the output of this command.

Returns¶

a list of ObjectPropertyInfo describing object properties

Since¶

2.12

`CanHostSocketcanProperties` (Object)¶

Properties for can-host-socketcan objects.

Members¶

if: string: interface name of the host system CAN bus to connect to
canbus: string: object ID of the can-bus object to connect to the host interface

Since¶

2.12

`ColoCompareProperties` (Object)¶

Properties for colo-compare objects.

Members¶

primary_in: string: name of the character device backend to use for the primary input (incoming packets are redirected to outdev)
secondary_in: string: name of the character device backend to use for secondary input (incoming packets are only compared to the input on primary_in and then dropped)
outdev: string: name of the character device backend to use for output
iothread: string: name of the iothread to run in
notify_dev: string (optional): name of the character device backend to be used to communicate with the remote colo-frame (only for Xen COLO)
compare_timeout: int (optional): the maximum time to hold a packet from primary_in for comparison with an incoming packet on secondary_in in milliseconds (default: 3000)
expired_scan_cycle: int (optional): the interval at which colo-compare checks whether packets from primary have timed out, in milliseconds (default: 3000)
max_queue_size: int (optional): the maximum number of packets to keep in the queue for comparing with incoming packets from secondary_in. If the queue is full and addtional packets are received, the addtional packets are dropped. (default: 1024)
vnet_hdr_support: boolean (optional): if true, vnet header support is enabled (default: false)

Since¶

2.8

`CryptodevBackendProperties` (Object)¶

Properties for cryptodev-backend and cryptodev-backend-builtin objects.

Members¶

queues: int (optional): the number of queues for the cryptodev backend. Ignored for cryptodev-backend and must be 1 for cryptodev-backend-builtin. (default: 1)

Since¶

2.8

`CryptodevVhostUserProperties` (Object)¶

Properties for cryptodev-vhost-user objects.

Members¶

chardev: string: the name of a Unix domain socket character device that connects to the vhost-user server
The members of CryptodevBackendProperties

Since¶

2.12

`DBusVMStateProperties` (Object)¶

Properties for dbus-vmstate objects.

Members¶

addr: string: the name of the DBus bus to connect to
id-list: string (optional): a comma separated list of DBus IDs of helpers whose data should be included in the VM state on migration

Since¶

5.0

`NetfilterInsert` (Enum)¶

Indicates where to insert a netfilter relative to a given other filter.

Values¶

before: insert before the specified filter
behind: insert behind the specified filter

Since¶

5.0

`NetfilterProperties` (Object)¶

Properties for objects of classes derived from netfilter.

Members¶

netdev: string: id of the network device backend to filter
queue: NetFilterDirection (optional): indicates which queue(s) to filter (default: all)
status: string (optional): indicates whether the filter is enabled (“on”) or disabled (“off”) (default: “on”)
position: string (optional): specifies where the filter should be inserted in the filter list. “head” means the filter is inserted at the head of the filter list, before any existing filters. “tail” means the filter is inserted at the tail of the filter list, behind any existing filters (default). “id=<id>” means the filter is inserted before or behind the filter specified by <id>, depending on the insert property. (default: “tail”)
insert: NetfilterInsert (optional): where to insert the filter relative to the filter given in position. Ignored if position is “head” or “tail”. (default: behind)

Since¶

2.5

`FilterBufferProperties` (Object)¶

Properties for filter-buffer objects.

Members¶

interval: int: a non-zero interval in microseconds. All packets arriving in the given interval are delayed until the end of the interval.
The members of NetfilterProperties

Since¶

2.5

`FilterDumpProperties` (Object)¶

Properties for filter-dump objects.

Members¶

file: string: the filename where the dumped packets should be stored
maxlen: int (optional): maximum number of bytes in a packet that are stored (default: 65536)
The members of NetfilterProperties

Since¶

2.5

`FilterMirrorProperties` (Object)¶

Properties for filter-mirror objects.

Members¶

outdev: string: the name of a character device backend to which all incoming packets are mirrored
vnet_hdr_support: boolean (optional): if true, vnet header support is enabled (default: false)
The members of NetfilterProperties

Since¶

2.6

`FilterRedirectorProperties` (Object)¶

Properties for filter-redirector objects.

At least one of indev or outdev must be present. If both are present, they must not refer to the same character device backend.

Members¶

indev: string (optional): the name of a character device backend from which packets are received and redirected to the filtered network device
outdev: string (optional): the name of a character device backend to which all incoming packets are redirected
vnet_hdr_support: boolean (optional): if true, vnet header support is enabled (default: false)
The members of NetfilterProperties

Since¶

2.6

`FilterRewriterProperties` (Object)¶

Properties for filter-rewriter objects.

Members¶

vnet_hdr_support: boolean (optional): if true, vnet header support is enabled (default: false)
The members of NetfilterProperties

Since¶

2.8

`InputBarrierProperties` (Object)¶

Properties for input-barrier objects.

Members¶

name: string: the screen name as declared in the screens section of barrier.conf
server: string (optional): hostname of the Barrier server (default: “localhost”)
port: string (optional): TCP port of the Barrier server (default: “24800”)
x-origin: string (optional): x coordinate of the leftmost pixel on the guest screen (default: “0”)
y-origin: string (optional): y coordinate of the topmost pixel on the guest screen (default: “0”)
width: string (optional): the width of secondary screen in pixels (default: “1920”)
height: string (optional): the height of secondary screen in pixels (default: “1080”)

Since¶

4.2

`InputLinuxProperties` (Object)¶

Properties for input-linux objects.

Members¶

evdev: string: the path of the host evdev device to use
grab_all: boolean (optional): if true, grab is toggled for all devices (e.g. both keyboard and mouse) instead of just one device (default: false)
repeat: boolean (optional): enables auto-repeat events (default: false)
grab-toggle: GrabToggleKeys (optional): the key or key combination that toggles device grab (default: ctrl-ctrl)

Since¶

2.6

`IothreadProperties` (Object)¶

Properties for iothread objects.

Members¶

poll-max-ns: int (optional): the maximum number of nanoseconds to busy wait for events. 0 means polling is disabled (default: 32768 on POSIX hosts, 0 otherwise)
poll-grow: int (optional): the multiplier used to increase the polling time when the algorithm detects it is missing events due to not polling long enough. 0 selects a default behaviour (default: 0)
poll-shrink: int (optional): the divisor used to decrease the polling time when the algorithm detects it is spending too long polling without encountering events. 0 selects a default behaviour (default: 0)

Since¶

2.0

`MemoryBackendProperties` (Object)¶

Properties for objects of classes derived from memory-backend.

Members¶

merge: boolean (optional): if true, mark the memory as mergeable (default depends on the machine type)
dump: boolean (optional): if true, include the memory in core dumps (default depends on the machine type)
host-nodes: array of int (optional): the list of NUMA host nodes to bind the memory to
policy: HostMemPolicy (optional): the NUMA policy (default: ‘default’)
prealloc: boolean (optional): if true, preallocate memory (default: false)
prealloc-threads: int (optional): number of CPU threads to use for prealloc (default: 1)
share: boolean (optional): if false, the memory is private to QEMU; if true, it is shared (default: false)
size: int: size of the memory region in bytes
x-use-canonical-path-for-ramblock-id: boolean (optional): if true, the canoncial path is used for ramblock-id. Disable this for 4.0 machine types or older to allow migration with newer QEMU versions. This option is considered stable despite the x- prefix. (default: false generally, but true for machine types <= 4.0)

Since¶

2.1

`MemoryBackendFileProperties` (Object)¶

Properties for memory-backend-file objects.

Members¶

align: int (optional): the base address alignment when QEMU mmap(2)s mem-path. Some backend stores specified by mem-path require an alignment different than the default one used by QEMU, e.g. the device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In such cases, users can specify the required alignment via this option. 0 selects a default alignment (currently the page size). (default: 0)
discard-data: boolean (optional): if true, the file contents can be destroyed when QEMU exits, to avoid unnecessarily flushing data to the backing file. Note that discard-data is only an optimization, and QEMU might not discard file contents if it aborts unexpectedly or is terminated using SIGKILL. (default: false)
mem-path: string: the path to either a shared memory or huge page filesystem mount
pmem: boolean (optional) (If: defined(CONFIG_LIBPMEM)): specifies whether the backing file specified by mem-path is in host persistent memory that can be accessed using the SNIA NVM programming model (e.g. Intel NVDIMM).
readonly: boolean (optional): if true, the backing file is opened read-only; if false, it is opened read-write. (default: false)
The members of MemoryBackendProperties

Since¶

2.1

`MemoryBackendMemfdProperties` (Object)¶

Properties for memory-backend-memfd objects.

The share boolean option is true by default with memfd.

Members¶

hugetlb: boolean (optional): if true, the file to be created resides in the hugetlbfs filesystem (default: false)
hugetlbsize: int (optional): the hugetlb page size on systems that support multiple hugetlb page sizes (it must be a power of 2 value supported by the system). 0 selects a default page size. This option is ignored if hugetlb is false. (default: 0)
seal: boolean (optional): if true, create a sealed-file, which will block further resizing of the memory (default: true)
The members of MemoryBackendProperties

Since¶

2.12

`PrManagerHelperProperties` (Object)¶

Properties for pr-manager-helper objects.

Members¶

path: string: the path to a Unix domain socket for connecting to the external helper

Since¶

2.11

`RemoteObjectProperties` (Object)¶

Properties for x-remote-object objects.

Members¶

fd: string: file descriptor name previously passed via ‘getfd’ command
devid: string: the id of the device to be associated with the file descriptor

Since¶

6.0

`RngProperties` (Object)¶

Properties for objects of classes derived from rng.

Members¶

opened: boolean (optional): if true, the device is opened immediately when applying this option and will probably fail when processing the next option. Don’t use; only provided for compatibility. (default: false)

Features¶

deprecated: Member opened is deprecated. Setting true doesn’t make sense, and false is already the default.

Since¶

1.3

`RngEgdProperties` (Object)¶

Properties for rng-egd objects.

Members¶

chardev: string: the name of a character device backend that provides the connection to the RNG daemon
The members of RngProperties

Since¶

1.3

`RngRandomProperties` (Object)¶

Properties for rng-random objects.

Members¶

filename: string (optional): the filename of the device on the host to obtain entropy from (default: “/dev/urandom”)
The members of RngProperties

Since¶

1.3

`SevGuestProperties` (Object)¶

Properties for sev-guest objects.

Members¶

sev-device: string (optional): SEV device to use (default: “/dev/sev”)
dh-cert-file: string (optional): guest owners DH certificate (encoded with base64)
session-file: string (optional): guest owners session parameters (encoded with base64)
policy: int (optional): SEV policy value (default: 0x1)
handle: int (optional): SEV firmware handle (default: 0)
cbitpos: int (optional): C-bit location in page table entry (default: 0)
reduced-phys-bits: int: number of bits in physical addresses that become unavailable when SEV is enabled

Since¶

2.12

`ObjectType` (Enum)¶

Values¶

authz-list: Not documented
authz-listfile: Not documented
authz-pam: Not documented
authz-simple: Not documented
can-bus: Not documented
can-host-socketcan: Not documented
colo-compare: Not documented
cryptodev-backend: Not documented
cryptodev-backend-builtin: Not documented
cryptodev-vhost-user (If: defined(CONFIG_VHOST_CRYPTO)): Not documented
dbus-vmstate: Not documented
filter-buffer: Not documented
filter-dump: Not documented
filter-mirror: Not documented
filter-redirector: Not documented
filter-replay: Not documented
filter-rewriter: Not documented
input-barrier: Not documented
input-linux: Not documented
iothread: Not documented
memory-backend-file: Not documented
memory-backend-memfd (If: defined(CONFIG_LINUX)): Not documented
memory-backend-ram: Not documented
pef-guest: Not documented
pr-manager-helper: Not documented
rng-builtin: Not documented
rng-egd: Not documented
rng-random: Not documented
secret: Not documented
secret_keyring: Not documented
sev-guest: Not documented
s390-pv-guest: Not documented
throttle-group: Not documented
tls-creds-anon: Not documented
tls-creds-psk: Not documented
tls-creds-x509: Not documented
tls-cipher-suites: Not documented
x-remote-object: Not documented

Since¶

6.0

`ObjectOptions` (Object)¶

Describes the options of a user creatable QOM object.

Members¶

qom-type: ObjectType: the class name for the object to be created
id: string: the name of the new object
The members of AuthZListProperties when qom-type is "authz-list"
The members of AuthZListFileProperties when qom-type is "authz-listfile"
The members of AuthZPAMProperties when qom-type is "authz-pam"
The members of AuthZSimpleProperties when qom-type is "authz-simple"
The members of CanHostSocketcanProperties when qom-type is "can-host-socketcan"
The members of ColoCompareProperties when qom-type is "colo-compare"
The members of CryptodevBackendProperties when qom-type is "cryptodev-backend"
The members of CryptodevBackendProperties when qom-type is "cryptodev-backend-builtin"
The members of CryptodevVhostUserProperties when qom-type is "cryptodev-vhost-user" (If: defined(CONFIG_VHOST_CRYPTO))
The members of DBusVMStateProperties when qom-type is "dbus-vmstate"
The members of FilterBufferProperties when qom-type is "filter-buffer"
The members of FilterDumpProperties when qom-type is "filter-dump"
The members of FilterMirrorProperties when qom-type is "filter-mirror"
The members of FilterRedirectorProperties when qom-type is "filter-redirector"
The members of NetfilterProperties when qom-type is "filter-replay"
The members of FilterRewriterProperties when qom-type is "filter-rewriter"
The members of InputBarrierProperties when qom-type is "input-barrier"
The members of InputLinuxProperties when qom-type is "input-linux"
The members of IothreadProperties when qom-type is "iothread"
The members of MemoryBackendFileProperties when qom-type is "memory-backend-file"
The members of MemoryBackendMemfdProperties when qom-type is "memory-backend-memfd" (If: defined(CONFIG_LINUX))
The members of MemoryBackendProperties when qom-type is "memory-backend-ram"
The members of PrManagerHelperProperties when qom-type is "pr-manager-helper"
The members of RngProperties when qom-type is "rng-builtin"
The members of RngEgdProperties when qom-type is "rng-egd"
The members of RngRandomProperties when qom-type is "rng-random"
The members of SecretProperties when qom-type is "secret"
The members of SecretKeyringProperties when qom-type is "secret_keyring"
The members of SevGuestProperties when qom-type is "sev-guest"
The members of ThrottleGroupProperties when qom-type is "throttle-group"
The members of TlsCredsAnonProperties when qom-type is "tls-creds-anon"
The members of TlsCredsPskProperties when qom-type is "tls-creds-psk"
The members of TlsCredsX509Properties when qom-type is "tls-creds-x509"
The members of TlsCredsProperties when qom-type is "tls-cipher-suites"
The members of RemoteObjectProperties when qom-type is "x-remote-object"

Since¶

6.0

`object-add` (Command)¶

Create a QOM object.

Arguments¶

The members of ObjectOptions

Returns¶

Nothing on success Error if qom-type is not a valid class name

Since¶

2.0

Example¶

-> { "execute": "object-add",
     "arguments": { "qom-type": "rng-random", "id": "rng1",
                    "filename": "/dev/hwrng" } }
<- { "return": {} }

`object-del` (Command)¶

Remove a QOM object.

Arguments¶

id: string: the name of the QOM object to remove

Returns¶

Nothing on success Error if id is not a valid id for a QOM object

Since¶

2.0

Example¶

-> { "execute": "object-del", "arguments": { "id": "rng1" } }
<- { "return": {} }

Device infrastructure (qdev)¶

`device-list-properties` (Command)¶

List properties associated with a device.

Arguments¶

typename: string: the type name of a device

Returns¶

a list of ObjectPropertyInfo describing a devices properties

Note¶

objects can create properties at runtime, for example to describe links between different devices and/or objects. These properties are not included in the output of this command.

Since¶

1.2

`device_add` (Command)¶

Arguments¶

driver: string: the name of the new device’s driver
bus: string (optional): the device’s parent bus (device tree path)
id: string (optional): the device’s ID, must be unique

Additional arguments depend on the type.

Add a device.

Notes¶

For detailed information about this command, please refer to the ‘docs/qdev-device-use.txt’ file.
It’s possible to list device properties by running QEMU with the “-device DEVICE,help” command-line argument, where DEVICE is the device’s name

Example¶

-> { "execute": "device_add",
     "arguments": { "driver": "e1000", "id": "net1",
                    "bus": "pci.0",
                    "mac": "52:54:00:12:34:56" } }
<- { "return": {} }

TODO¶

This command effectively bypasses QAPI completely due to its “additional arguments” business. It shouldn’t have been added to the schema in this form. It should be qapified properly, or replaced by a properly qapified command.

Since¶

0.13

`device_del` (Command)¶

Remove a device from a guest

Arguments¶

id: string: the device’s ID or QOM path

Returns¶

Nothing on success If id is not a valid device, DeviceNotFound

Notes¶

When this command completes, the device may not be removed from the guest. Hot removal is an operation that requires guest cooperation. This command merely requests that the guest begin the hot removal process. Completion of the device removal process is signaled with a DEVICE_DELETED event. Guest reset will automatically complete removal for all devices.

Since¶

0.14

Example¶

-> { "execute": "device_del",
     "arguments": { "id": "net1" } }
<- { "return": {} }

-> { "execute": "device_del",
     "arguments": { "id": "/machine/peripheral-anon/device[0]" } }
<- { "return": {} }

`DEVICE_DELETED` (Event)¶

Emitted whenever the device removal completion is acknowledged by the guest. At this point, it’s safe to reuse the specified device ID. Device removal can be initiated by the guest or by HMP/QMP commands.

Arguments¶

device: string (optional): device name
path: string: device path

Since¶

1.5

Example¶

<- { "event": "DEVICE_DELETED",
     "data": { "device": "virtio-net-pci-0",
               "path": "/machine/peripheral/virtio-net-pci-0" },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

Machines¶

`SysEmuTarget` (Enum)¶

The comprehensive enumeration of QEMU system emulation (“softmmu”) targets. Run “./configure –help” in the project root directory, and look for the *-softmmu targets near the “–target-list” option. The individual target constants are not documented here, for the time being.

Values¶

rx: since 5.0
avr: since 5.1
aarch64: Not documented
alpha: Not documented
arm: Not documented
cris: Not documented
hppa: Not documented
i386: Not documented
m68k: Not documented
microblaze: Not documented
microblazeel: Not documented
mips: Not documented
mips64: Not documented
mips64el: Not documented
mipsel: Not documented
nios2: Not documented
or1k: Not documented
ppc: Not documented
ppc64: Not documented
riscv32: Not documented
riscv64: Not documented
s390x: Not documented
sh4: Not documented
sh4eb: Not documented
sparc: Not documented
sparc64: Not documented
tricore: Not documented
x86_64: Not documented
xtensa: Not documented
xtensaeb: Not documented

Notes¶

The resulting QMP strings can be appended to the “qemu-system-” prefix to produce the corresponding QEMU executable name. This is true even for “qemu-system-x86_64”.

Since¶

3.0

`CpuS390State` (Enum)¶

An enumeration of cpu states that can be assumed by a virtual S390 CPU

Values¶

uninitialized: Not documented
stopped: Not documented
check-stop: Not documented
operating: Not documented
load: Not documented

Since¶

2.12

`CpuInfoS390` (Object)¶

Additional information about a virtual S390 CPU

Members¶

cpu-state: CpuS390State: the virtual CPU’s state

Since¶

2.12

`CpuInfoFast` (Object)¶

Information about a virtual CPU

Members¶

cpu-index: int: index of the virtual CPU
qom-path: string: path to the CPU object in the QOM tree
thread-id: int: ID of the underlying host thread
props: CpuInstanceProperties (optional): properties describing to which node/socket/core/thread virtual CPU belongs to, provided if supported by board
target: SysEmuTarget: the QEMU system emulation target, which determines which additional fields will be listed (since 3.0)
The members of CpuInfoS390 when target is "s390x"

Since¶

2.12

`query-cpus-fast` (Command)¶

Returns information about all virtual CPUs.

Returns¶

list of CpuInfoFast

Since¶

2.12

Example¶

-> { "execute": "query-cpus-fast" }
<- { "return": [
        {
            "thread-id": 25627,
            "props": {
                "core-id": 0,
                "thread-id": 0,
                "socket-id": 0
            },
            "qom-path": "/machine/unattached/device[0]",
            "arch":"x86",
            "target":"x86_64",
            "cpu-index": 0
        },
        {
            "thread-id": 25628,
            "props": {
                "core-id": 0,
                "thread-id": 0,
                "socket-id": 1
            },
            "qom-path": "/machine/unattached/device[2]",
            "arch":"x86",
            "target":"x86_64",
            "cpu-index": 1
        }
    ]
}

`MachineInfo` (Object)¶

Information describing a machine.

Members¶

name: string: the name of the machine
alias: string (optional): an alias for the machine name
is-default: boolean (optional): whether the machine is default
cpu-max: int: maximum number of CPUs supported by the machine type (since 1.5)
hotpluggable-cpus: boolean: cpu hotplug via -device is supported (since 2.7)
numa-mem-supported: boolean: true if ‘-numa node,mem’ option is supported by the machine type and false otherwise (since 4.1)
deprecated: boolean: if true, the machine type is deprecated and may be removed in future versions of QEMU according to the QEMU deprecation policy (since 4.1)
default-cpu-type: string (optional): default CPU model typename if none is requested via the -cpu argument. (since 4.2)
default-ram-id: string (optional): the default ID of initial RAM memory backend (since 5.2)

Example¶

-> { "execute": "system_wakeup" }
<- { "return": {} }

`LostTickPolicy` (Enum)¶

Policy for handling lost ticks in timer devices. Ticks end up getting lost when, for example, the guest is paused.

Values¶

discard: throw away the missed ticks and continue with future injection normally. The guest OS will see the timer jump ahead by a potentially quite significant amount all at once, as if the intervening chunk of time had simply not existed; needless to say, such a sudden jump can easily confuse a guest OS which is not specifically prepared to deal with it. Assuming the guest OS can deal correctly with the time jump, the time in the guest and in the host should now match.
delay: continue to deliver ticks at the normal rate. The guest OS will not notice anything is amiss, as from its point of view time will have continued to flow normally. The time in the guest should now be behind the time in the host by exactly the amount of time during which ticks have been missed.
slew: deliver ticks at a higher rate to catch up with the missed ticks. The guest OS will not notice anything is amiss, as from its point of view time will have continued to flow normally. Once the timer has managed to catch up with all the missing ticks, the time in the guest and in the host should match.

Example¶

-> { "execute": "query-kvm" }
<- { "return": { "enabled": true, "present": true } }

`NumaOptionsType` (Enum)¶

Values¶

node: NUMA nodes configuration
dist: NUMA distance configuration (since 2.10)
cpu: property based CPU(s) to node mapping (Since: 2.10)
hmat-lb: memory latency and bandwidth information (Since: 5.0)
hmat-cache: memory side cache information (Since: 5.0)

Since¶

2.1

`NumaOptions` (Object)¶

A discriminated record of NUMA options. (for OptsVisitor)

Members¶

type: NumaOptionsType: Not documented
The members of NumaNodeOptions when type is "node"
The members of NumaDistOptions when type is "dist"
The members of NumaCpuOptions when type is "cpu"
The members of NumaHmatLBOptions when type is "hmat-lb"
The members of NumaHmatCacheOptions when type is "hmat-cache"

Since¶

2.1

`NumaNodeOptions` (Object)¶

Create a guest NUMA node. (for OptsVisitor)

Members¶

nodeid: int (optional)

NUMA node ID (increase by 1 from 0 if omitted)

cpus: array of int (optional)

VCPUs belonging to this node (assign VCPUS round-robin: if omitted)

mem: int (optional)

memory size of this node; mutually exclusive with memdev. Equally divide total memory among nodes if both mem and memdev are omitted.

memdev: string (optional)

memory backend object. If specified for one node, it must be specified for all nodes.

initiator: int (optional)

The members of CpuInstanceProperties

Since¶

2.10

`HmatLBMemoryHierarchy` (Enum)¶

The memory hierarchy in the System Locality Latency and Bandwidth Information Structure of HMAT (Heterogeneous Memory Attribute Table)

For more information about HmatLBMemoryHierarchy, see chapter 5.2.27.4: Table 5-146: Field “Flags” of ACPI 6.3 spec.

Values¶

memory: the structure represents the memory performance
first-level: first level of memory side cache
second-level: second level of memory side cache
third-level: third level of memory side cache

Since¶

5.0

`HmatLBDataType` (Enum)¶

Data type in the System Locality Latency and Bandwidth Information Structure of HMAT (Heterogeneous Memory Attribute Table)

For more information about HmatLBDataType, see chapter 5.2.27.4: Table 5-146: Field “Data Type” of ACPI 6.3 spec.

Values¶

access-latency: access latency (nanoseconds)
read-latency: read latency (nanoseconds)
write-latency: write latency (nanoseconds)
access-bandwidth: access bandwidth (Bytes per second)
read-bandwidth: read bandwidth (Bytes per second)
write-bandwidth: write bandwidth (Bytes per second)

Since¶

5.0

`NumaHmatLBOptions` (Object)¶

Set the system locality latency and bandwidth information between Initiator and Target proximity Domains.

For more information about NumaHmatLBOptions, see chapter 5.2.27.4: Table 5-146 of ACPI 6.3 spec.

Members¶

initiator: int: the Initiator Proximity Domain.
target: int: the Target Proximity Domain.
hierarchy: HmatLBMemoryHierarchy: the Memory Hierarchy. Indicates the performance of memory or side cache.
data-type: HmatLBDataType: presents the type of data, access/read/write latency or hit latency.
latency: int (optional): the value of latency from initiator to target proximity domain, the latency unit is “ns(nanosecond)”.
bandwidth: int (optional): the value of bandwidth between initiator and target proximity domain, the bandwidth unit is “Bytes per second”.

Since¶

5.0

`HmatCacheAssociativity` (Enum)¶

Cache associativity in the Memory Side Cache Information Structure of HMAT

For more information of HmatCacheAssociativity, see chapter 5.2.27.5: Table 5-147 of ACPI 6.3 spec.

Values¶

none

None (no memory side cache in this proximity domain,: or cache associativity unknown)

direct

Direct Mapped

complex

Complex Cache Indexing (implementation specific)

Since¶

5.0

`HmatCacheWritePolicy` (Enum)¶

Cache write policy in the Memory Side Cache Information Structure of HMAT

For more information of HmatCacheWritePolicy, see chapter 5.2.27.5: Table 5-147: Field “Cache Attributes” of ACPI 6.3 spec.

Values¶

none: None (no memory side cache in this proximity domain, or cache write policy unknown)
write-back: Write Back (WB)
write-through: Write Through (WT)

Since¶

5.0

`NumaHmatCacheOptions` (Object)¶

Set the memory side cache information for a given memory domain.

For more information of NumaHmatCacheOptions, see chapter 5.2.27.5: Table 5-147: Field “Cache Attributes” of ACPI 6.3 spec.

Members¶

node-id: int: the memory proximity domain to which the memory belongs.
size: int: the size of memory side cache in bytes.
level: int: the cache level described in this structure.
associativity: HmatCacheAssociativity: the cache associativity, none/direct-mapped/complex(complex cache indexing).
policy: HmatCacheWritePolicy: the write policy, none/write-back/write-through.
line: int: the cache Line size in bytes.

Since¶

5.0

`memsave` (Command)¶

Save a portion of guest memory to a file.

Arguments¶

val: int: the virtual address of the guest to start from
size: int: the size of memory region to save
filename: string: the file to save the memory to as binary data
cpu-index: int (optional): the index of the virtual CPU to use for translating the virtual address (defaults to CPU 0)

Returns¶

Nothing on success

Since¶

0.14

Notes¶

Errors were not reliably returned until 1.1

Example¶

-> { "execute": "memsave",
     "arguments": { "val": 10,
                    "size": 100,
                    "filename": "/tmp/virtual-mem-dump" } }
<- { "return": {} }

`pmemsave` (Command)¶

Save a portion of guest physical memory to a file.

Arguments¶

val: int: the physical address of the guest to start from
size: int: the size of memory region to save
filename: string: the file to save the memory to as binary data

Returns¶

Nothing on success

Since¶

0.14

Notes¶

Errors were not reliably returned until 1.1

Example¶

-> { "execute": "pmemsave",
     "arguments": { "val": 10,
                    "size": 100,
                    "filename": "/tmp/physical-mem-dump" } }
<- { "return": {} }

`Memdev` (Object)¶

Information about memory backend

Members¶

id: string (optional): backend’s ID if backend has ‘id’ property (since 2.9)
size: int: memory backend size
merge: boolean: enables or disables memory merge support
dump: boolean: includes memory backend’s memory in a core dump or not
prealloc: boolean: enables or disables memory preallocation
host-nodes: array of int: host nodes for its memory policy
policy: HostMemPolicy: memory policy of memory backend

2.7

Example¶

For pseries machine type started with -smp 2,cores=2,maxcpus=4 -cpu POWER8:

-> { "execute": "query-hotpluggable-cpus" }
<- {"return": [
     { "props": { "core": 8 }, "type": "POWER8-spapr-cpu-core",
       "vcpus-count": 1 },
     { "props": { "core": 0 }, "type": "POWER8-spapr-cpu-core",
       "vcpus-count": 1, "qom-path": "/machine/unattached/device[0]"}
   ]}'

For pc machine type started with -smp 1,maxcpus=2:

-> { "execute": "query-hotpluggable-cpus" }
<- {"return": [
     {
        "type": "qemu64-x86_64-cpu", "vcpus-count": 1,
        "props": {"core-id": 0, "socket-id": 1, "thread-id": 0}
     },
     {
        "qom-path": "/machine/unattached/device[0]",
        "type": "qemu64-x86_64-cpu", "vcpus-count": 1,
        "props": {"core-id": 0, "socket-id": 0, "thread-id": 0}
     }
   ]}

For s390x-virtio-ccw machine type started with -smp 1,maxcpus=2 -cpu qemu
(Since: 2.11):

-> { "execute": "query-hotpluggable-cpus" }
<- {"return": [
     {
        "type": "qemu-s390x-cpu", "vcpus-count": 1,
        "props": { "core-id": 1 }
     },
     {
        "qom-path": "/machine/unattached/device[0]",
        "type": "qemu-s390x-cpu", "vcpus-count": 1,
        "props": { "core-id": 0 }
     }
   ]}

`set-numa-node` (Command)¶

Runtime equivalent of ‘-numa’ CLI option, available at preconfigure stage to configure numa mapping before initializing machine.

Since 3.0

Arguments¶

The members of NumaOptions

`balloon` (Command)¶

Request the balloon driver to change its balloon size.

Arguments¶

value: int

the target logical size of the VM in bytes. We can deduce the size of the balloon using this formula:

logical_vm_size = vm_ram_size - balloon_size

From it we have: balloon_size = vm_ram_size - value

Returns¶

Nothing on success
If the balloon driver is enabled but not functional because the KVM kernel module cannot support it, KvmMissingCap
If no balloon device is present, DeviceNotActive

Notes¶

This command just issues a request to the guest. When it returns, the balloon size may not have changed. A guest can change the balloon size independent of this command.

Since¶

0.14

Example¶

-> { "execute": "balloon", "arguments": { "value": 536870912 } }
<- { "return": {} }

With a 2.5GiB guest this command inflated the ballon to 3GiB.

`BalloonInfo` (Object)¶

Information about the guest balloon device.

Members¶

actual: int: the logical size of the VM in bytes Formula used: logical_vm_size = vm_ram_size - balloon_size

Since¶

0.14

`query-balloon` (Command)¶

Return information about the balloon device.

Returns¶

BalloonInfo on success
If the balloon driver is enabled but not functional because the KVM kernel module cannot support it, KvmMissingCap
If no balloon device is present, DeviceNotActive

Since¶

0.14

Example¶

-> { "execute": "query-balloon" }
<- { "return": {
         "actual": 1073741824,
      }
   }

`BALLOON_CHANGE` (Event)¶

Emitted when the guest changes the actual BALLOON level. This value is equivalent to the actual field return by the ‘query-balloon’ command

Arguments¶

actual: int: the logical size of the VM in bytes Formula used: logical_vm_size = vm_ram_size - balloon_size

Note¶

this event is rate-limited.

Since¶

1.2

Example¶

<- { "event": "BALLOON_CHANGE",
     "data": { "actual": 944766976 },
     "timestamp": { "seconds": 1267020223, "microseconds": 435656 } }

`MemoryInfo` (Object)¶

Actual memory information in bytes.

Members¶

base-memory: int: size of “base” memory specified with command line option -m.
plugged-memory: int (optional): size of memory that can be hot-unplugged. This field is omitted if target doesn’t support memory hotplug (i.e. CONFIG_MEM_DEVICE not defined at build time).

Since¶

2.11

`query-memory-size-summary` (Command)¶

Return the amount of initially allocated and present hotpluggable (if enabled) memory in bytes.

Example¶

-> { "execute": "query-memory-size-summary" }
<- { "return": { "base-memory": 4294967296, "plugged-memory": 0 } }

Since¶

2.11

`PCDIMMDeviceInfo` (Object)¶

PCDIMMDevice state information

Members¶

id: string (optional): device’s ID
addr: int: physical address, where device is mapped
size: int: size of memory that the device provides
slot: int: slot number at which device is plugged in
node: int: NUMA node number where device is plugged in
memdev: string: memory backend linked with device
hotplugged: boolean: true if device was hotplugged
hotpluggable: boolean: true if device if could be added/removed while machine is running

Since¶

2.1

`VirtioPMEMDeviceInfo` (Object)¶

VirtioPMEM state information

Members¶

id: string (optional): device’s ID
memaddr: int: physical address in memory, where device is mapped
size: int: size of memory that the device provides
memdev: string: memory backend linked with device

Since¶

4.1

`VirtioMEMDeviceInfo` (Object)¶

VirtioMEMDevice state information

Members¶

id: string (optional): device’s ID
memaddr: int: physical address in memory, where device is mapped
requested-size: int: the user requested size of the device
size: int: the (current) size of memory that the device provides
max-size: int: the maximum size of memory that the device can provide
block-size: int: the block size of memory that the device provides
node: int: NUMA node number where device is assigned to
memdev: string: memory backend linked with the region

Since¶

5.1

`MemoryDeviceInfo` (Object)¶

Union containing information about a memory device

nvdimm is included since 2.12. virtio-pmem is included since 4.1. virtio-mem is included since 5.1.

Members¶

type: One of dimm, nvdimm, virtio-pmem, virtio-mem
data: PCDIMMDeviceInfo when type is "dimm"
data: PCDIMMDeviceInfo when type is "nvdimm"
data: VirtioPMEMDeviceInfo when type is "virtio-pmem"
data: VirtioMEMDeviceInfo when type is "virtio-mem"

Since¶

2.1

`query-memory-devices` (Command)¶

Lists available memory devices and their state

Since¶

2.1

Example¶

-> { "execute": "query-memory-devices" }
<- { "return": [ { "data":
                      { "addr": 5368709120,
                        "hotpluggable": true,
                        "hotplugged": true,
                        "id": "d1",
                        "memdev": "/objects/memX",
                        "node": 0,
                        "size": 1073741824,
                        "slot": 0},
                   "type": "dimm"
                 } ] }

`MEMORY_DEVICE_SIZE_CHANGE` (Event)¶

Emitted when the size of a memory device changes. Only emitted for memory devices that can actually change the size (e.g., virtio-mem due to guest action).

Arguments¶

id: string (optional): device’s ID
size: int: the new size of memory that the device provides

Note¶

this event is rate-limited.

Since¶

5.1

Example¶

<- { "event": "MEMORY_DEVICE_SIZE_CHANGE",
     "data": { "id": "vm0", "size": 1073741824},
     "timestamp": { "seconds": 1588168529, "microseconds": 201316 } }

`MEM_UNPLUG_ERROR` (Event)¶

Emitted when memory hot unplug error occurs.

Arguments¶

device: string: device name
msg: string: Informative message

Since¶

2.4

Example¶

<- { "event": "MEM_UNPLUG_ERROR"
     "data": { "device": "dimm1",
               "msg": "acpi: device unplug for unsupported device"
     },
     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }

`CpuModelInfo` (Object)¶

Virtual CPU model.

A CPU model consists of the name of a CPU definition, to which delta changes are applied (e.g. features added/removed). Most magic values that an architecture might require should be hidden behind the name. However, if required, architectures can expose relevant properties.

Members¶

name: string: the name of the CPU definition the model is based on
props: value (optional): a dictionary of QOM properties to be applied

Since¶

2.8

`CpuModelExpansionType` (Enum)¶

An enumeration of CPU model expansion types.

Values¶

static: Expand to a static CPU model, a combination of a static base model name and property delta changes. As the static base model will never change, the expanded CPU model will be the same, independent of QEMU version, machine type, machine options, and accelerator options. Therefore, the resulting model can be used by tooling without having to specify a compatibility machine - e.g. when displaying the “host” model. The static CPU models are migration-safe.
full: Expand all properties. The produced model is not guaranteed to be migration-safe, but allows tooling to get an insight and work with model details.

`CpuModelCompareInfo` (Object)¶

The result of a CPU model comparison.

Members¶

result: CpuModelCompareResult: The result of the compare operation.
responsible-properties: array of string: List of properties that led to the comparison result not being identical.

responsible-properties is a list of QOM property names that led to both CPUs not being detected as identical. For identical models, this list is empty. If a QOM property is read-only, that means there’s no known way to make the CPU models identical. If the special property name “type” is included, the models are by definition not identical and cannot be made identical.

Since¶

2.8

If¶

defined(TARGET_S390X)

`query-cpu-model-comparison` (Command)¶

Compares two CPU models, returning how they compare in a specific configuration. The results indicates how both models compare regarding runnability. This result can be used by tooling to make decisions if a certain CPU model will run in a certain configuration or if a compatible CPU model has to be created by baselining.

Usually, a CPU model is compared against the maximum possible CPU model of a certain configuration (e.g. the “host” model for KVM). If that CPU model is identical or a subset, it will run in that configuration.

The result returned by this command may be affected by:

QEMU version: CPU models may look different depending on the QEMU version. (Except for CPU models reported as “static” in query-cpu-definitions.)
machine-type: CPU model may look different depending on the machine-type. (Except for CPU models reported as “static” in query-cpu-definitions.)
machine options (including accelerator): in some architectures, CPU models may look different depending on machine and accelerator options. (Except for CPU models reported as “static” in query-cpu-definitions.)
“-cpu” arguments and global properties: arguments to the -cpu option and global properties may affect expansion of CPU models. Using query-cpu-model-expansion while using these is not advised.

Some architectures may not support comparing CPU models. s390x supports comparing CPU models.

Arguments¶

modela: CpuModelInfo: Not documented
modelb: CpuModelInfo: Not documented

Returns¶

a CpuModelBaselineInfo. Returns an error if comparing CPU models is not supported, if a model cannot be used, if a model contains an unknown cpu definition name, unknown properties or properties with wrong types.

Note¶

this command isn’t specific to s390x, but is only implemented on this architecture currently.

Since¶

2.8

If¶

defined(TARGET_S390X)

`query-cpu-model-baseline` (Command)¶

Baseline two CPU models, creating a compatible third model. The created model will always be a static, migration-safe CPU model (see “static” CPU model expansion for details).

This interface can be used by tooling to create a compatible CPU model out two CPU models. The created CPU model will be identical to or a subset of both CPU models when comparing them. Therefore, the created CPU model is guaranteed to run where the given CPU models run.

The result returned by this command may be affected by:

QEMU version: CPU models may look different depending on the QEMU version. (Except for CPU models reported as “static” in query-cpu-definitions.)
machine-type: CPU model may look different depending on the machine-type. (Except for CPU models reported as “static” in query-cpu-definitions.)
machine options (including accelerator): in some architectures, CPU models may look different depending on machine and accelerator options. (Except for CPU models reported as “static” in query-cpu-definitions.)
“-cpu” arguments and global properties: arguments to the -cpu option and global properties may affect expansion of CPU models. Using query-cpu-model-expansion while using these is not advised.

Some architectures may not support baselining CPU models. s390x supports baselining CPU models.

Arguments¶

modela: CpuModelInfo: Not documented
modelb: CpuModelInfo: Not documented

Returns¶

a CpuModelBaselineInfo. Returns an error if baselining CPU models is not supported, if a model cannot be used, if a model contains an unknown cpu definition name, unknown properties or properties with wrong types.

Note¶

this command isn’t specific to s390x, but is only implemented on this architecture currently.

Since¶

2.8

If¶

defined(TARGET_S390X)

`CpuModelExpansionInfo` (Object)¶

The result of a cpu model expansion.

Members¶

model: CpuModelInfo: the expanded CpuModelInfo.

Since¶

2.8

If¶

defined(TARGET_S390X) || defined(TARGET_I386) || defined(TARGET_ARM)

`query-cpu-model-expansion` (Command)¶

Expands a given CPU model (or a combination of CPU model + additional options) to different granularities, allowing tooling to get an understanding what a specific CPU model looks like in QEMU under a certain configuration.

This interface can be used to query the “host” CPU model.

The data returned by this command may be affected by:

QEMU version: CPU models may look different depending on the QEMU version. (Except for CPU models reported as “static” in query-cpu-definitions.)
machine-type: CPU model may look different depending on the machine-type. (Except for CPU models reported as “static” in query-cpu-definitions.)
machine options (including accelerator): in some architectures, CPU models may look different depending on machine and accelerator options. (Except for CPU models reported as “static” in query-cpu-definitions.)
“-cpu” arguments and global properties: arguments to the -cpu option and global properties may affect expansion of CPU models. Using query-cpu-model-expansion while using these is not advised.

Some architectures may not support all expansion types. s390x supports “full” and “static”. Arm only supports “full”.

Arguments¶

type: CpuModelExpansionType: Not documented
model: CpuModelInfo: Not documented

Returns¶

a CpuModelExpansionInfo. Returns an error if expanding CPU models is not supported, if the model cannot be expanded, if the model contains an unknown CPU definition name, unknown properties or properties with a wrong type. Also returns an error if an expansion type is not supported.

Since¶

2.8

If¶

defined(TARGET_S390X) || defined(TARGET_I386) || defined(TARGET_ARM)

`CpuDefinitionInfo` (Object)¶

Virtual CPU definition.

Members¶

name: string: the name of the CPU definition
migration-safe: boolean (optional): whether a CPU definition can be safely used for migration in combination with a QEMU compatibility machine when migrating between different QEMU versions and between hosts with different sets of (hardware or software) capabilities. If not provided, information is not available and callers should not assume the CPU definition to be migration-safe. (since 2.8)
static: boolean: whether a CPU definition is static and will not change depending on QEMU version, machine type, machine options and accelerator options. A static model is always migration-safe. (since 2.8)
unavailable-features: array of string (optional): List of properties that prevent the CPU model from running in the current host. (since 2.8)
typename: string: Type name that can be used as argument to device-list-properties, to introspect properties configurable using -cpu or -global. (since 2.9)
alias-of: string (optional): Name of CPU model this model is an alias for. The target of the CPU model alias may change depending on the machine type. Management software is supposed to translate CPU model aliases in the VM configuration, because aliases may stop being migration-safe in the future (since 4.1)
deprecated: boolean: If true, this CPU model is deprecated and may be removed in in some future version of QEMU according to the QEMU deprecation policy. (since 5.2)

unavailable-features is a list of QOM property names that represent CPU model attributes that prevent the CPU from running. If the QOM property is read-only, that means there’s no known way to make the CPU model run in the current host. Implementations that choose not to provide specific information return the property name “type”. If the property is read-write, it means that it MAY be possible to run the CPU model in the current host if that property is changed. Management software can use it as hints to suggest or choose an alternative for the user, or just to generate meaningful error messages explaining why the CPU model can’t be used. If unavailable-features is an empty list, the CPU model is runnable using the current host and machine-type. If unavailable-features is not present, runnability information for the CPU is not available.

Since¶

1.2

If¶

defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_I386) || defined(TARGET_S390X) || defined(TARGET_MIPS)

`query-cpu-definitions` (Command)¶

Return a list of supported virtual CPU definitions

Returns¶

a list of CpuDefInfo

Since¶

1.2

If¶

defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_I386) || defined(TARGET_S390X) || defined(TARGET_MIPS)

Record/replay¶

`ReplayMode` (Enum)¶

Mode of the replay subsystem.

Values¶

none: normal execution mode. Replay or record are not enabled.
record: record mode. All non-deterministic data is written into the replay log.
play: replay mode. Non-deterministic data required for system execution is read from the log.

Since¶

2.5

`ReplayInfo` (Object)¶

Record/replay information.

Members¶

mode: ReplayMode: current mode.
filename: string (optional): name of the record/replay log file. It is present only in record or replay modes, when the log is recorded or replayed.
icount: int: current number of executed instructions.

Since¶

5.2

`query-replay` (Command)¶

Retrieve the record/replay information. It includes current instruction count which may be used for replay-break and replay-seek commands.

Returns¶

record/replay information.

Since¶

5.2

Example¶

-> { "execute": "query-replay" }
<- { "return": { "mode": "play", "filename": "log.rr", "icount": 220414 } }

`replay-break` (Command)¶

Set replay breakpoint at instruction count icount. Execution stops when the specified instruction is reached. There can be at most one breakpoint. When breakpoint is set, any prior one is removed. The breakpoint may be set only in replay mode and only “in the future”, i.e. at instruction counts greater than the current one. The current instruction count can be observed with query-replay.

Arguments¶

icount: int: instruction count to stop at

Since¶

5.2

Example¶

-> { "execute": "replay-break", "data": { "icount": 220414 } }

`replay-delete-break` (Command)¶

Remove replay breakpoint which was set with replay-break. The command is ignored when there are no replay breakpoints.

Since¶

5.2

Example¶

-> { "execute": "replay-delete-break" }

`replay-seek` (Command)¶

Automatically proceed to the instruction count icount, when replaying the execution. The command automatically loads nearest snapshot and replays the execution to find the desired instruction. When there is no preceding snapshot or the execution is not replayed, then the command fails. icount for the reference may be obtained with query-replay command.

Arguments¶

icount: int: target instruction count

Since¶

5.2

Example¶

-> { "execute": "replay-seek", "data": { "icount": 220414 } }

Yank feature¶

`YankInstanceType` (Enum)¶

An enumeration of yank instance types. See YankInstance for more information.

Values¶

block-node: Not documented
chardev: Not documented
migration: Not documented

Since¶

6.0

`YankInstanceBlockNode` (Object)¶

Specifies which block graph node to yank. See YankInstance for more information.

Members¶

node-name: string: the name of the block graph node

Since¶

6.0

`YankInstanceChardev` (Object)¶

Specifies which character device to yank. See YankInstance for more information.

Members¶

id: string: the chardev’s ID

Since¶

6.0

`YankInstance` (Object)¶

A yank instance can be yanked with the yank qmp command to recover from a hanging QEMU.

Currently implemented yank instances:

nbd block device: Yanking it will shut down the connection to the nbd server without attempting to reconnect.
socket chardev: Yanking it will shut down the connected socket.
migration: Yanking it will shut down all migration connections. Unlike migrate_cancel, it will not notify the migration process, so migration will go into failed state, instead of cancelled state. yank should be used to recover from hangs.

Members¶

type: YankInstanceType: Not documented
The members of YankInstanceBlockNode when type is "block-node"
The members of YankInstanceChardev when type is "chardev"

Since¶

6.0

`yank` (Command)¶

Try to recover from hanging QEMU by yanking the specified instances. See YankInstance for more information.

Takes a list of YankInstance as argument.

Arguments¶

instances: array of YankInstance: Not documented

Returns¶

Nothing on success
DeviceNotFound error, if any of the YankInstances doesn’t exist

Example¶

-> { "execute": "yank",
     "arguments": {
         "instances": [
              { "type": "block-node",
                "node-name": "nbd0" }
         ] } }
<- { "return": {} }

Since¶

6.0

`query-yank` (Command)¶

Query yank instances. See YankInstance for more information.

Returns¶

list of YankInstance

Example¶

-> { "execute": "query-yank" }
<- { "return": [
         { "type": "block-node",
           "node-name": "nbd0" }
     ] }

Since¶

6.0

Miscellanea¶

`add_client` (Command)¶

Allow client connections for VNC, Spice and socket based character devices to be passed in to QEMU via SCM_RIGHTS.

Arguments¶

protocol: string: protocol name. Valid names are “vnc”, “spice” or the name of a character device (eg. from -chardev id=XXXX)
fdname: string: file descriptor name previously passed via ‘getfd’ command
skipauth: boolean (optional): whether to skip authentication. Only applies to “vnc” and “spice” protocols
tls: boolean (optional): whether to perform TLS. Only applies to the “spice” protocol

Returns¶

nothing on success.

Since¶

0.14

Example¶

-> { "execute": "add_client", "arguments": { "protocol": "vnc",
                                             "fdname": "myclient" } }
<- { "return": {} }

`NameInfo` (Object)¶

Guest name information.

Members¶

name: string (optional): The name of the guest

Since¶

0.14

`query-name` (Command)¶

Return the name information of a guest.

Returns¶

NameInfo of the guest

Since¶

0.14

Example¶

-> { "execute": "query-name" }
<- { "return": { "name": "qemu-name" } }

`IOThreadInfo` (Object)¶

Information about an iothread

Members¶

id: string: the identifier of the iothread
thread-id: int: ID of the underlying host thread
poll-max-ns: int: maximum polling time in ns, 0 means polling is disabled (since 2.9)
poll-grow: int: how many ns will be added to polling time, 0 means that it’s not configured (since 2.9)
poll-shrink: int: how many ns will be removed from polling time, 0 means that it’s not configured (since 2.9)

This command makes QEMU exit the preconfig state and proceed with VM initialization using configuration data provided on the command line and via the QMP monitor during the preconfig state. The command is only available during the preconfig state (i.e. when the –preconfig command line option was in use).

Since 3.0

Returns¶

nothing

Example¶

-> { "execute": "x-exit-preconfig" }
<- { "return": {} }

`human-monitor-command` (Command)¶

Execute a command on the human monitor and return the output.

Arguments¶

command-line: string: the command to execute in the human monitor
cpu-index: int (optional): The CPU to use for commands that require an implicit CPU

Features¶

savevm-monitor-nodes: If present, HMP command savevm only snapshots monitor-owned nodes if they have no parents. This allows the use of ‘savevm’ with -blockdev. (since 4.2)

Returns¶

the output of the command as a string

Since¶

0.14

Notes¶

This command only exists as a stop-gap. Its use is highly discouraged. The semantics of this command are not guaranteed: this means that command names, arguments and responses can change or be removed at ANY time. Applications that rely on long term stability guarantees should NOT use this command.

Known limitations:

This command is stateless, this means that commands that depend on state information (such as getfd) might not work
Commands that prompt the user for data don’t currently work

Example¶

-> { "execute": "human-monitor-command",
     "arguments": { "command-line": "info kvm" } }
<- { "return": "kvm support: enabled\r\n" }

`getfd` (Command)¶

Receive a file descriptor via SCM rights and assign it a name

Arguments¶

fdname: string: file descriptor name

Returns¶

Nothing on success

Since¶

0.14

Notes¶

If fdname already exists, the file descriptor assigned to it will be closed and replaced by the received file descriptor.

The ‘closefd’ command can be used to explicitly close the file descriptor when it is no longer needed.

Example¶

-> { "execute": "getfd", "arguments": { "fdname": "fd1" } }
<- { "return": {} }

`closefd` (Command)¶

Close a file descriptor previously passed via SCM rights

Arguments¶

fdname: string: file descriptor name

Returns¶

Nothing on success

Since¶

0.14

Example¶

-> { "execute": "closefd", "arguments": { "fdname": "fd1" } }
<- { "return": {} }

`AddfdInfo` (Object)¶

Information about a file descriptor that was added to an fd set.

Members¶

fdset-id: int: The ID of the fd set that fd was added to.
fd: int: The file descriptor that was received via SCM rights and added to the fd set.

Since¶

1.2

`add-fd` (Command)¶

Add a file descriptor, that was passed via SCM rights, to an fd set.

Arguments¶

fdset-id: int (optional): The ID of the fd set to add the file descriptor to.
opaque: string (optional): A free-form string that can be used to describe the fd.

Returns¶

AddfdInfo on success
If file descriptor was not received, FdNotSupplied
If fdset-id is a negative value, InvalidParameterValue

Notes¶

The list of fd sets is shared by all monitor connections.

If fdset-id is not specified, a new fd set will be created.

Since¶

1.2

Example¶

-> { "execute": "add-fd", "arguments": { "fdset-id": 1 } }
<- { "return": { "fdset-id": 1, "fd": 3 } }

`remove-fd` (Command)¶

Remove a file descriptor from an fd set.

Arguments¶

fdset-id: int: The ID of the fd set that the file descriptor belongs to.
fd: int (optional): The file descriptor that is to be removed.

Returns¶

Nothing on success
If fdset-id or fd is not found, FdNotFound

Since¶

1.2

Notes¶

The list of fd sets is shared by all monitor connections.

If fd is not specified, all file descriptors in fdset-id will be removed.

Example¶

-> { "execute": "remove-fd", "arguments": { "fdset-id": 1, "fd": 3 } }
<- { "return": {} }

`FdsetFdInfo` (Object)¶

Information about a file descriptor that belongs to an fd set.

Members¶

fd: int: The file descriptor value.
opaque: string (optional): A free-form string that can be used to describe the fd.

Since¶

1.2

`FdsetInfo` (Object)¶

Information about an fd set.

Members¶

fdset-id: int: The ID of the fd set.
fds: array of FdsetFdInfo: A list of file descriptors that belong to this fd set.

Since¶

1.2

`query-fdsets` (Command)¶

Return information describing all fd sets.

Returns¶

A list of FdsetInfo

Since¶

1.2

Note¶

The list of fd sets is shared by all monitor connections.

Example¶

-> { "execute": "query-fdsets" }
<- { "return": [
       {
         "fds": [
           {
             "fd": 30,
             "opaque": "rdonly:/path/to/file"
           },
           {
             "fd": 24,
             "opaque": "rdwr:/path/to/file"
           }
         ],
         "fdset-id": 1
       },
       {
         "fds": [
           {
             "fd": 28
           },
           {
             "fd": 29
           }
         ],
         "fdset-id": 0
       }
     ]
   }

`CommandLineParameterType` (Enum)¶

Possible types for an option parameter.

Values¶

string: accepts a character string
boolean: accepts “on” or “off”
number: accepts a number
size: accepts a number followed by an optional suffix (K)ilo, (M)ega, (G)iga, (T)era

Since¶

1.5

`CommandLineParameterInfo` (Object)¶

Details about a single parameter of a command line option.

Members¶

name: string: parameter name
type: CommandLineParameterType: parameter CommandLineParameterType
help: string (optional): human readable text string, not suitable for parsing.
default: string (optional): default value string (since 2.1)

Since¶

1.5

`CommandLineOptionInfo` (Object)¶

Details about a command line option, including its list of parameter details

Members¶

option: string: option name
parameters: array of CommandLineParameterInfo: an array of CommandLineParameterInfo

Since¶

1.5

`query-command-line-options` (Command)¶

Query command line option schema.

Arguments¶

option: string (optional): option name

Returns¶

list of CommandLineOptionInfo for all options (or for the given option). Returns an error if the given option doesn’t exist.

Since¶

1.5

Example¶

-> { "execute": "query-command-line-options",
     "arguments": { "option": "option-rom" } }
<- { "return": [
        {
            "parameters": [
                {
                    "name": "romfile",
                    "type": "string"
                },
                {
                    "name": "bootindex",
                    "type": "number"
                }
            ],
            "option": "option-rom"
        }
     ]
   }

`RTC_CHANGE` (Event)¶

Emitted when the guest changes the RTC time.

Arguments¶

offset: int: offset between base RTC clock (as specified by -rtc base), and new RTC clock value

Note¶

This event is rate-limited.

Since¶

0.13

Example¶

<-   { "event": "RTC_CHANGE",
       "data": { "offset": 78 },
       "timestamp": { "seconds": 1267020223, "microseconds": 435656 } }

If¶

defined(TARGET_ALPHA) || defined(TARGET_ARM) || defined(TARGET_HPPA) || defined(TARGET_I386) || defined(TARGET_MIPS) || defined(TARGET_MIPS64) || defined(TARGET_PPC) || defined(TARGET_PPC64) || defined(TARGET_S390X) || defined(TARGET_SH4) || defined(TARGET_SPARC)

`rtc-reset-reinjection` (Command)¶

This command will reset the RTC interrupt reinjection backlog. Can be used if another mechanism to synchronize guest time is in effect, for example QEMU guest agent’s guest-set-time command.

Since¶

2.1

Example¶

-> { "execute": "rtc-reset-reinjection" }
<- { "return": {} }

If¶

defined(TARGET_I386)

`SevState` (Enum)¶

An enumeration of SEV state information used during query-sev.

Values¶

uninit: The guest is uninitialized.
launch-update: The guest is currently being launched; plaintext data and register state is being imported.
launch-secret: The guest is currently being launched; ciphertext data is being imported.
running: The guest is fully launched or migrated in.
send-update: The guest is currently being migrated out to another machine.
receive-update: The guest is currently being migrated from another machine.

Since¶

2.12

If¶

defined(TARGET_I386)

`SevInfo` (Object)¶

Information about Secure Encrypted Virtualization (SEV) support

Members¶

enabled: boolean: true if SEV is active
api-major: int: SEV API major version
api-minor: int: SEV API minor version
build-id: int: SEV FW build id
policy: int: SEV policy value
state: SevState: SEV guest state
handle: int: SEV firmware handle

If¶

defined(TARGET_I386)

`dump-skeys` (Command)¶

Dump guest’s storage keys

Arguments¶

filename: string: the path to the file to dump to

This command is only supported on s390 architecture.

Since¶

2.5

Example¶

-> { "execute": "dump-skeys",
     "arguments": { "filename": "/tmp/skeys" } }
<- { "return": {} }

If¶

defined(TARGET_S390X)

`GICCapability` (Object)¶

The struct describes capability for a specific GIC (Generic Interrupt Controller) version. These bits are not only decided by QEMU/KVM software version, but also decided by the hardware that the program is running upon.

Members¶

version: int: version of GIC to be described. Currently, only 2 and 3 are supported.
emulated: boolean: whether current QEMU/hardware supports emulated GIC device in user space.
kernel: boolean: whether current QEMU/hardware supports hardware accelerated GIC device in kernel.

Since¶

2.6

If¶

defined(TARGET_ARM)

`query-gic-capabilities` (Command)¶

This command is ARM-only. It will return a list of GICCapability objects that describe its capability bits.

Returns¶

a list of GICCapability objects.

Since¶

2.6

Example¶

-> { "execute": "query-gic-capabilities" }
<- { "return": [{ "version": 2, "emulated": true, "kernel": false },
                { "version": 3, "emulated": false, "kernel": true } ] }

If¶

defined(TARGET_ARM)

Audio¶

`AudiodevPerDirectionOptions` (Object)¶

General audio backend options that are used for both playback and recording.

Members¶

mixing-engine: boolean (optional): use QEMU’s mixing engine to mix all streams inside QEMU and convert audio formats when not supported by the backend. When set to off, fixed-settings must be also off (default on, since 4.2)
fixed-settings: boolean (optional): use fixed settings for host input/output. When off, frequency, channels and format must not be specified (default true)
frequency: int (optional): frequency to use when using fixed settings (default 44100)
channels: int (optional): number of channels when using fixed settings (default 2)
voices: int (optional): number of voices to use (default 1)
format: AudioFormat (optional): sample format to use when using fixed settings (default s16)
buffer-length: int (optional): the buffer length in microseconds

Since¶

4.0

`AudiodevGenericOptions` (Object)¶

Generic driver-specific options.

Members¶

in: AudiodevPerDirectionOptions (optional): options of the capture stream
out: AudiodevPerDirectionOptions (optional): options of the playback stream

Since¶

4.0

`AudiodevAlsaPerDirectionOptions` (Object)¶

Options of the ALSA backend that are used for both playback and recording.

Members¶

dev: string (optional): the name of the ALSA device to use (default ‘default’)
period-length: int (optional): the period length in microseconds
try-poll: boolean (optional): attempt to use poll mode, falling back to non-polling access on failure (default true)
The members of AudiodevPerDirectionOptions

Since¶

4.0

`AudiodevAlsaOptions` (Object)¶

Options of the ALSA audio backend.

Members¶

in: AudiodevAlsaPerDirectionOptions (optional): options of the capture stream
out: AudiodevAlsaPerDirectionOptions (optional): options of the playback stream
threshold: int (optional): set the threshold (in microseconds) when playback starts

Since¶

4.0

`AudiodevCoreaudioPerDirectionOptions` (Object)¶

Options of the Core Audio backend that are used for both playback and recording.

Members¶

buffer-count: int (optional): number of buffers
The members of AudiodevPerDirectionOptions

Since¶

4.0

`AudiodevCoreaudioOptions` (Object)¶

Options of the coreaudio audio backend.

Members¶

in: AudiodevCoreaudioPerDirectionOptions (optional): options of the capture stream
out: AudiodevCoreaudioPerDirectionOptions (optional): options of the playback stream

Since¶

4.0

`AudiodevDsoundOptions` (Object)¶

Options of the DirectSound audio backend.

Members¶

in: AudiodevPerDirectionOptions (optional): options of the capture stream
out: AudiodevPerDirectionOptions (optional): options of the playback stream
latency: int (optional): add extra latency to playback in microseconds (default 10000)

Since¶

4.0

`AudiodevJackPerDirectionOptions` (Object)¶

Options of the JACK backend that are used for both playback and recording.

Members¶

server-name: string (optional): select from among several possible concurrent server instances (default: environment variable $JACK_DEFAULT_SERVER if set, else “default”)
client-name: string (optional): the client name to use. The server will modify this name to create a unique variant, if needed unless exact-name is true (default: the guest’s name)
connect-ports: string (optional): if set, a regular expression of JACK client port name(s) to monitor for and automatically connect to
start-server: boolean (optional): start a jack server process if one is not already present (default: false)
exact-name: boolean (optional): use the exact name requested otherwise JACK automatically generates a unique one, if needed (default: false)
The members of AudiodevPerDirectionOptions

Since¶

5.1

`AudiodevJackOptions` (Object)¶

Options of the JACK audio backend.

Members¶

in: AudiodevJackPerDirectionOptions (optional): options of the capture stream
out: AudiodevJackPerDirectionOptions (optional): options of the playback stream

Since¶

5.1

`AudiodevOssPerDirectionOptions` (Object)¶

Options of the OSS backend that are used for both playback and recording.

Members¶

dev: string (optional): file name of the OSS device (default ‘/dev/dsp’)
buffer-count: int (optional): number of buffers
try-poll: boolean (optional): attempt to use poll mode, falling back to non-polling access on failure (default true)
The members of AudiodevPerDirectionOptions

Since¶

4.0

`AudiodevOssOptions` (Object)¶

Options of the OSS audio backend.

Members¶

in: AudiodevOssPerDirectionOptions (optional): options of the capture stream
out: AudiodevOssPerDirectionOptions (optional): options of the playback stream
try-mmap: boolean (optional): try using memory-mapped access, falling back to non-memory-mapped access on failure (default true)
exclusive: boolean (optional): open device in exclusive mode (vmix won’t work) (default false)
dsp-policy: int (optional): set the timing policy of the device (between 0 and 10, where smaller number means smaller latency but higher CPU usage) or -1 to use fragment mode (option ignored on some platforms) (default 5)

Since¶

4.0

`AudiodevPaPerDirectionOptions` (Object)¶

Options of the Pulseaudio backend that are used for both playback and recording.

Members¶

name: string (optional): name of the sink/source to use
stream-name: string (optional): name of the PulseAudio stream created by qemu. Can be used to identify the stream in PulseAudio when you create multiple PulseAudio devices or run multiple qemu instances (default: audiodev’s id, since 4.2)
latency: int (optional): latency you want PulseAudio to achieve in microseconds (default 15000)
The members of AudiodevPerDirectionOptions

Since¶

4.0

`AudiodevPaOptions` (Object)¶

Options of the PulseAudio audio backend.

Members¶

in: AudiodevPaPerDirectionOptions (optional): options of the capture stream
out: AudiodevPaPerDirectionOptions (optional): options of the playback stream
server: string (optional): PulseAudio server address (default: let PulseAudio choose)

Since¶

4.0

`AudiodevSdlPerDirectionOptions` (Object)¶

Options of the SDL audio backend that are used for both playback and recording.

Members¶

buffer-count: int (optional): number of buffers (default 4)
The members of AudiodevPerDirectionOptions

Since¶

6.0

`AudiodevSdlOptions` (Object)¶

Options of the SDL audio backend.

Members¶

in: AudiodevSdlPerDirectionOptions (optional): options of the recording stream
out: AudiodevSdlPerDirectionOptions (optional): options of the playback stream

Since¶

6.0

`AudiodevWavOptions` (Object)¶

Options of the wav audio backend.

Members¶

in: AudiodevPerDirectionOptions (optional): options of the capture stream
out: AudiodevPerDirectionOptions (optional): options of the playback stream
path: string (optional): name of the wav file to record (default ‘qemu.wav’)

Since¶

4.0

`AudioFormat` (Enum)¶

An enumeration of possible audio formats.

Values¶

u8: unsigned 8 bit integer
s8: signed 8 bit integer
u16: unsigned 16 bit integer
s16: signed 16 bit integer
u32: unsigned 32 bit integer
s32: signed 32 bit integer
f32: single precision floating-point (since 5.0)

Since¶

4.0

`AudiodevDriver` (Enum)¶

An enumeration of possible audio backend drivers.

Values¶

jack: JACK audio backend (since 5.1)
none: Not documented
alsa: Not documented
coreaudio: Not documented
dsound: Not documented
oss: Not documented
pa: Not documented
sdl: Not documented
spice: Not documented
wav: Not documented

Since¶

4.0

`Audiodev` (Object)¶

Options of an audio backend.

Members¶

id: string: identifier of the backend
driver: AudiodevDriver: the backend driver to use
timer-period: int (optional): timer period (in microseconds, 0: use lowest possible)
The members of AudiodevGenericOptions when driver is "none"
The members of AudiodevAlsaOptions when driver is "alsa"
The members of AudiodevCoreaudioOptions when driver is "coreaudio"
The members of AudiodevDsoundOptions when driver is "dsound"
The members of AudiodevJackOptions when driver is "jack"
The members of AudiodevOssOptions when driver is "oss"
The members of AudiodevPaOptions when driver is "pa"
The members of AudiodevSdlOptions when driver is "sdl"
The members of AudiodevGenericOptions when driver is "spice"
The members of AudiodevWavOptions when driver is "wav"

Since¶

4.0

ACPI¶

`AcpiTableOptions` (Object)¶

Specify an ACPI table on the command line to load.

At most one of file and data can be specified. The list of files specified by any one of them is loaded and concatenated in order. If both are omitted, data is implied.

Other fields / optargs can be used to override fields of the generic ACPI table header; refer to the ACPI specification 5.0, section 5.2.6 System Description Table Header. If a header field is not overridden, then the corresponding value from the concatenated blob is used (in case of file), or it is filled in with a hard-coded value (in case of data).

String fields are copied into the matching ACPI member from lowest address upwards, and silently truncated / NUL-padded to length.

Members¶

sig: string (optional): table signature / identifier (4 bytes)
rev: int (optional): table revision number (dependent on signature, 1 byte)
oem_id: string (optional): OEM identifier (6 bytes)
oem_table_id: string (optional): OEM table identifier (8 bytes)
oem_rev: int (optional): OEM-supplied revision number (4 bytes)
asl_compiler_id: string (optional): identifier of the utility that created the table (4 bytes)
asl_compiler_rev: int (optional): revision number of the utility that created the table (4 bytes)
file: string (optional): colon (:) separated list of pathnames to load and concatenate as table data. The resultant binary blob is expected to have an ACPI table header. At least one file is required. This field excludes data.
data: string (optional): colon (:) separated list of pathnames to load and concatenate as table data. The resultant binary blob must not have an ACPI table header. At least one file is required. This field excludes file.

Since¶

1.5

`ACPISlotType` (Enum)¶

Values¶

DIMM: memory slot
CPU: logical CPU slot (since 2.7)

`ACPIOSTInfo` (Object)¶

OSPM Status Indication for a device For description of possible values of source and status fields see “_OST (OSPM Status Indication)” chapter of ACPI5.0 spec.

Members¶

device: string (optional): device ID associated with slot
slot: string: slot ID, unique per slot of a given slot-type
slot-type: ACPISlotType: type of the slot
source: int: an integer containing the source event
status: int: an integer containing the status code

Since¶

2.1

`query-acpi-ospm-status` (Command)¶

Return a list of ACPIOSTInfo for devices that support status reporting via ACPI _OST method.

Since¶

2.1

Example¶

-> { "execute": "query-acpi-ospm-status" }
<- { "return": [ { "device": "d1", "slot": "0", "slot-type": "DIMM", "source": 1, "status": 0},
                 { "slot": "1", "slot-type": "DIMM", "source": 0, "status": 0},
                 { "slot": "2", "slot-type": "DIMM", "source": 0, "status": 0},
                 { "slot": "3", "slot-type": "DIMM", "source": 0, "status": 0}
   ]}

`ACPI_DEVICE_OST` (Event)¶

Emitted when guest executes ACPI _OST method.

Arguments¶

info: ACPIOSTInfo: OSPM Status Indication

Since¶

2.1

Example¶

<- { "event": "ACPI_DEVICE_OST",
     "data": { "device": "d1", "slot": "0",
               "slot-type": "DIMM", "source": 1, "status": 0 } }

PCI¶

`PciMemoryRange` (Object)¶

A PCI device memory region

Members¶

base: int: the starting address (guest physical)
limit: int: the ending address (guest physical)

Since¶

0.14

`PciMemoryRegion` (Object)¶

Information about a PCI device I/O region.

Members¶

bar: int

the index of the Base Address Register for this region

type: string

‘io’ if the region is a PIO region
‘memory’ if the region is a MMIO region

size: int

memory size

prefetch: boolean (optional)

if type is ‘memory’, true if the memory is prefetchable

mem_type_64: boolean (optional)

if type is ‘memory’, true if the BAR is 64-bit

address: int

-> { "execute": "query-pci" }
<- { "return": [
         {
            "bus": 0,
            "devices": [
               {
                  "bus": 0,
                  "qdev_id": "",
                  "slot": 0,
                  "class_info": {
                     "class": 1536,
                     "desc": "Host bridge"
                  },
                  "id": {
                     "device": 32902,
                     "vendor": 4663
                  },
                  "function": 0,
                  "regions": [
                  ]
               },
               {
                  "bus": 0,
                  "qdev_id": "",
                  "slot": 1,
                  "class_info": {
                     "class": 1537,
                     "desc": "ISA bridge"
                  },
                  "id": {
                     "device": 32902,
                     "vendor": 28672
                  },
                  "function": 0,
                  "regions": [
                  ]
               },
               {
                  "bus": 0,
                  "qdev_id": "",
                  "slot": 1,
                  "class_info": {
                     "class": 257,
                     "desc": "IDE controller"
                  },
                  "id": {
                     "device": 32902,
                     "vendor": 28688
                  },
                  "function": 1,
                  "regions": [
                     {
                        "bar": 4,
                        "size": 16,
                        "address": 49152,
                        "type": "io"
                     }
                  ]
               },
               {
                  "bus": 0,
                  "qdev_id": "",
                  "slot": 2,
                  "class_info": {
                     "class": 768,
                     "desc": "VGA controller"
                  },
                  "id": {
                     "device": 4115,
                     "vendor": 184
                  },
                  "function": 0,
                  "regions": [
                     {
                        "prefetch": true,
                        "mem_type_64": false,
                        "bar": 0,
                        "size": 33554432,
                        "address": 4026531840,
                        "type": "memory"
                     },
                     {
                        "prefetch": false,
                        "mem_type_64": false,
                        "bar": 1,
                        "size": 4096,
                        "address": 4060086272,
                        "type": "memory"
                     },
                     {
                        "prefetch": false,
                        "mem_type_64": false,
                        "bar": 6,
                        "size": 65536,
                        "address": -1,
                        "type": "memory"
                     }
                  ]
               },
               {
                  "bus": 0,
                  "qdev_id": "",
                  "irq": 11,
                  "slot": 4,
                  "class_info": {
                     "class": 1280,
                     "desc": "RAM controller"
                  },
                  "id": {
                     "device": 6900,
                     "vendor": 4098
                  },
                  "function": 0,
                  "regions": [
                     {
                        "bar": 0,
                        "size": 32,
                        "address": 49280,
                        "type": "io"
                     }
                  ]
               }
            ]
         }
      ]
   }

Note¶

This example has been shortened as the real response is too long.

QEMU QMP Reference Manual¶

Introduction¶

Stability Considerations¶

QMP errors¶

QapiErrorClass (Enum)¶

Values¶

Since¶

Common data types¶

IoOperationType (Enum)¶

Values¶

Since¶

OnOffAuto (Enum)¶

Values¶

Since¶

OnOffSplit (Enum)¶

Values¶

Since¶

String (Object)¶

Members¶

Since¶

StrOrNull (Alternate)¶

Members¶

Since¶

OffAutoPCIBAR (Enum)¶

Values¶

Since¶

PCIELinkSpeed (Enum)¶

Values¶

Since¶

PCIELinkWidth (Enum)¶

Values¶

Since¶

HostMemPolicy (Enum)¶

Values¶

Since¶

NetFilterDirection (Enum)¶

Values¶

Since¶

GrabToggleKeys (Enum)¶

Values¶

Since¶

Socket data types¶

NetworkAddressFamily (Enum)¶

Values¶

Since¶

InetSocketAddressBase (Object)¶

Members¶

InetSocketAddress (Object)¶

Members¶

Since¶

UnixSocketAddress (Object)¶

Members¶

Since¶

VsockSocketAddress (Object)¶

Members¶

Note¶

Since¶

SocketAddressLegacy (Object)¶

Members¶

Note¶

Since¶

SocketAddressType (Enum)¶

Values¶

Since¶

SocketAddress (Object)¶

Members¶

Since¶

VM run state¶

RunState (Enum)¶

Values¶

ShutdownCause (Enum)¶

Values¶

StatusInfo (Object)¶

Members¶

Since¶

Notes¶

query-status (Command)¶

Returns¶

Since¶

Example¶

`QapiErrorClass` (Enum)¶

`IoOperationType` (Enum)¶

`OnOffAuto` (Enum)¶

`OnOffSplit` (Enum)¶

`String` (Object)¶

`StrOrNull` (Alternate)¶

`OffAutoPCIBAR` (Enum)¶

`PCIELinkSpeed` (Enum)¶

`PCIELinkWidth` (Enum)¶

`HostMemPolicy` (Enum)¶

`NetFilterDirection` (Enum)¶

`GrabToggleKeys` (Enum)¶

`NetworkAddressFamily` (Enum)¶

`InetSocketAddressBase` (Object)¶

`InetSocketAddress` (Object)¶

`UnixSocketAddress` (Object)¶

`VsockSocketAddress` (Object)¶

`SocketAddressLegacy` (Object)¶

`SocketAddressType` (Enum)¶

`SocketAddress` (Object)¶

`RunState` (Enum)¶

`ShutdownCause` (Enum)¶

`StatusInfo` (Object)¶

`query-status` (Command)¶

`SHUTDOWN` (Event)¶

`POWERDOWN` (Event)¶

`RESET` (Event)¶

`STOP` (Event)¶

`RESUME` (Event)¶

`SUSPEND` (Event)¶

`SUSPEND_DISK` (Event)¶

`WAKEUP` (Event)¶

`WATCHDOG` (Event)¶

`WatchdogAction` (Enum)¶

`RebootAction` (Enum)¶

`ShutdownAction` (Enum)¶

`PanicAction` (Enum)¶

`watchdog-set-action` (Command)¶

`set-action` (Command)¶

`GUEST_PANICKED` (Event)¶

`GUEST_CRASHLOADED` (Event)¶

`GuestPanicAction` (Enum)¶

`GuestPanicInformationType` (Enum)¶

`GuestPanicInformation` (Object)¶