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 QEMU Machine Protocol Specification for detailed information on the Server command and response formats.
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
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
32
32.0GT/s (since 9.0)
64
64.0GT/s (since 9.0)
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
HumanReadableText
(Object)
Members
human-readable-text
:string
Formatted output intended for humans.
Since
6.2
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
andto
.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)
mptcp
:boolean
(optional) (If:HAVE_IPPROTO_MPTCP
)enable multi-path TCP. (Since 6.1)
- 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: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: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
Note
String types are used to allow for possible future hostname or service resolution support.
Since
2.8
FdSocketAddress
(Object)
A file descriptor name or number.
Members
str
:string
decimal is for file descriptor number, otherwise it’s a file descriptor name. Named file descriptors are permitted in monitor commands, in combination with the ‘getfd’ command. Decimal file descriptors are permitted at startup or other contexts where no monitor context is active.
Since
1.2
InetSocketAddressWrapper
(Object)
Members
data
:InetSocketAddress
internet domain socket address
Since
1.3
UnixSocketAddressWrapper
(Object)
Members
data
:UnixSocketAddress
UNIX domain socket address
Since
1.3
VsockSocketAddressWrapper
(Object)
Members
data
:VsockSocketAddress
VSOCK domain socket address
Since
2.8
FdSocketAddressWrapper
(Object)
Members
data
:FdSocketAddress
file descriptor name or number
Since
1.3
SocketAddressLegacy
(Object)
Captures the address of a socket, which could also be a named file descriptor
Members
type
:SocketAddressType
Transport type
- The members of
InetSocketAddressWrapper
whentype
is"inet"
- The members of
UnixSocketAddressWrapper
whentype
is"unix"
- The members of
VsockSocketAddressWrapper
whentype
is"vsock"
- The members of
FdSocketAddressWrapper
whentype
is"fd"
Since
1.3
SocketAddressType
(Enum)
Available SocketAddress types
Values
inet
Internet address
unix
Unix domain socket
vsock
VMCI address
fd
Socket file descriptor
Since
2.9
SocketAddress
(Object)
Captures the address of a socket, which could also be a socket file descriptor
Members
type
:SocketAddressType
Transport type
- The members of
InetSocketAddress
whentype
is"inet"
- The members of
UnixSocketAddress
whentype
is"unix"
- The members of
VsockSocketAddress
whentype
is"vsock"
- The members of
FdSocketAddress
whentype
is"fd"
Since
2.9
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
snapshot-load
A snapshot is being loaded by the record & replay subsystem. This value is used only within QEMU. It doesn’t occur in QMP. (since 7.2)
StatusInfo
(Object)
Information about VM run state
Members
running
:boolean
true if all VCPUs are runnable, false if not runnable
status
:RunState
the virtual machine
RunState
Since
0.14
query-status
(Command)
Query the run status of the VM
Returns
StatusInfo
reflecting the VM
Since
0.14
Example:
-> { "execute": "query-status" }
<- { "return": { "running": true,
"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, "reason": "guest-shutdown" },
"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, "reason": "guest-reset" },
"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 guestpoweroff
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
exit-failure
Shutdown the VM and exit with nonzero status (since 7.1)
Since
6.0
watchdog-set-action
(Command)
Set watchdog action.
Arguments
action
:WatchdogAction
WatchdogAction
action taken when watchdog timer expires.
Since
2.11
Example:
-> { "execute": "watchdog-set-action",
"arguments": { "action": "inject-nmi" } }
<- { "return": {} }
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.
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" },
"timestamp": { "seconds": 1648245231, "microseconds": 900001 } }
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" },
"timestamp": { "seconds": 1648245259, "microseconds": 893771 } }
GUEST_PVSHUTDOWN
(Event)
Emitted when guest submits a shutdown request via pvpanic interface
Since
9.1
Example:
<- { "event": "GUEST_PVSHUTDOWN",
"timestamp": { "seconds": 1648245259, "microseconds": 893771 } }
GuestPanicAction
(Enum)
An enumeration of the actions taken when guest OS panic is detected
Values
pause
system pauses
poweroff
system powers off (since 2.8)
run
system continues to run (since 5.0)
Since
2.1
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
whentype
is"hyper-v"
- The members of
GuestPanicInformationS390
whentype
is"s390"
Since
2.9
GuestPanicInformationHyperV
(Object)
Hyper-V specific guest panic information (HV crash MSRs)
Members
arg1
:int
for Windows, STOP code for the guest crash. For Linux, an error code.
arg2
:int
for Windows, first argument of the STOP. For Linux, the guest OS ID, which has the kernel version in bits 16-47 and 0x8100 in bits 48-63.
arg3
:int
for Windows, second argument of the STOP. For Linux, the program counter of the guest.
arg4
:int
for Windows, third argument of the STOP. For Linux, the RAX register (x86) or the stack pointer (aarch64) of the guest.
arg5
:int
for Windows, fourth argument of the STOP. For x86 Linux, the stack pointer of the guest.
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.
flags
:MemoryFailureFlags
flags for MemoryFailureAction.
Since
5.2
Example:
<- { "event": "MEMORY_FAILURE",
"data": { "recipient": "hypervisor",
"action": "fatal",
"flags": { "action-required": false,
"recursive": false } },
"timestamp": { "seconds": 1267061043, "microseconds": 959568 } }
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
NotifyVmexitOption
(Enum)
An enumeration of the options specified when enabling notify VM exit
Values
run
enable the feature, do nothing and continue if the notify VM exit happens.
internal-error
enable the feature, raise a internal error if the notify VM exit happens.
disable
disable the feature.
Since
7.2
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
DES with 56 bit / 8 byte keys. Do not use except in VNC. (since 6.1)
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
sm4
SM4 with 128 bit / 16 byte keys (since 9.0)
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
whenformat
is"qcow"
- The members of
QCryptoBlockOptionsLUKS
whenformat
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
whenformat
is"qcow"
- The members of
QCryptoBlockCreateOptionsLUKS
whenformat
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
detached-header
:boolean
whether the LUKS header is detached (Since 9.0)
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
whenformat
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
whenformat
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 ifkeyid
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
If
CONFIG_SECRET_KEYRING
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
QCryptoAkCipherAlgorithm
(Enum)
The supported algorithms for asymmetric encryption ciphers
Values
rsa
RSA algorithm
Since
7.1
QCryptoAkCipherKeyType
(Enum)
The type of asymmetric keys.
Values
public
Not documented
private
Not documented
Since
7.1
QCryptoRSAPaddingAlgorithm
(Enum)
The padding algorithm for RSA.
Values
raw
no padding used
pkcs1
pkcs1#v1.5
Since
7.1
QCryptoAkCipherOptionsRSA
(Object)
Specific parameters for RSA algorithm.
Members
hash-alg
:QCryptoHashAlgorithm
QCryptoHashAlgorithm
padding-alg
:QCryptoRSAPaddingAlgorithm
QCryptoRSAPaddingAlgorithm
Since
7.1
QCryptoAkCipherOptions
(Object)
The options that are available for all asymmetric key algorithms when creating a new QCryptoAkCipher.
Members
alg
:QCryptoAkCipherAlgorithm
encryption cipher algorithm
- The members of
QCryptoAkCipherOptionsRSA
whenalg
is"rsa"
Since
7.1
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 toready
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
change
see
block-job-change
(since 8.2)
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.
Arguments
id
:string
The job identifier.
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
tototal-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.
Returns
a list with a JobInfo
for each active job
Since
3.0
Block devices
Block core (VM unrelated)
SnapshotInfo
(Object)
Members
id
:string
unique snapshot id
name
:string
user chosen name
vm-state-size
:int
size of the VM state
date-sec
:int
UTC date of the snapshot in seconds
date-nsec
:int
fractional part in nano seconds to be used with date-sec
vm-clock-sec
:int
VM clock relative to boot in seconds
vm-clock-nsec
:int
fractional part in nano seconds to be used with vm-clock-sec
icount
:int
(optional)Current instruction count. Appears when execution record/replay is enabled. Used for “time-traveling” to match the moment in the recorded execution with the snapshots. This counter may be obtained through
query-replay
command (since 5.2)
Since
1.3
ImageInfoSpecificQCow2EncryptionBase
(Object)
Members
format
:BlockdevQcow2EncryptionFormat
The encryption format
Since
2.10
ImageInfoSpecificQCow2Encryption
(Object)
Members
- The members of
ImageInfoSpecificQCow2EncryptionBase
- The members of
QCryptoBlockInfoLUKS
whenformat
is"luks"
Since
2.10
ImageInfoSpecificQCow2
(Object)
Members
compat
:string
compatibility level
data-file
:string
(optional)the filename of the external data file that is stored in the image and used as a default for opening the image (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 (since: 4.0)
extended-l2
:boolean
(optional)true if the image has extended L2 entries; only valid for compat >= 1.1 (since 5.2)
lazy-refcounts
:boolean
(optional)on or off; only valid for compat >= 1.1
corrupt
:boolean
(optional)true if the image has been marked corrupt; only valid for compat >= 1.1 (since 2.2)
refcount-bits
:int
width of a refcount entry in bits (since 2.3)
encrypt
:ImageInfoSpecificQCow2Encryption
(optional)details about encryption parameters; only set if image is encrypted (since 2.10)
bitmaps
:array of Qcow2BitmapInfo
(optional)A list of qcow2 bitmap details (since 4.0)
compression-type
:Qcow2CompressionType
the image cluster compression method (since 5.1)
Since
1.7
ImageInfoSpecificVmdk
(Object)
Members
create-type
:string
The create type of VMDK image
cid
:int
Content id of image
parent-cid
:int
Parent VMDK image’s cid
extents
:array of VmdkExtentInfo
List of extent files
Since
1.7
VmdkExtentInfo
(Object)
Information about a VMDK extent file
Members
filename
:string
Name of the extent file
format
:string
Extent type (e.g. FLAT or SPARSE)
virtual-size
:int
Number of bytes covered by this extent
cluster-size
:int
(optional)Cluster size in bytes (for non-flat extents)
compressed
:boolean
(optional)Whether this extent contains compressed data
Since
8.0
ImageInfoSpecificRbd
(Object)
Members
encryption-format
:RbdImageEncryptionFormat
(optional)Image encryption format
Since
6.1
ImageInfoSpecificFile
(Object)
Members
extent-size-hint
:int
(optional)Extent size hint (if available)
Since
8.0
ImageInfoSpecificKind
(Enum)
Values
luks
Since 2.7
rbd
Since 6.1
file
Since 8.0
qcow2
Not documented
vmdk
Not documented
Since
1.7
ImageInfoSpecificQCow2Wrapper
(Object)
Members
data
:ImageInfoSpecificQCow2
image information specific to QCOW2
Since
1.7
ImageInfoSpecificVmdkWrapper
(Object)
Members
data
:ImageInfoSpecificVmdk
image information specific to VMDK
Since
6.1
ImageInfoSpecificLUKSWrapper
(Object)
Members
data
:QCryptoBlockInfoLUKS
image information specific to LUKS
Since
2.7
ImageInfoSpecificRbdWrapper
(Object)
Members
data
:ImageInfoSpecificRbd
image information specific to RBD
Since
6.1
ImageInfoSpecificFileWrapper
(Object)
Members
data
:ImageInfoSpecificFile
image information specific to files
Since
8.0
ImageInfoSpecific
(Object)
A discriminated record of image format specific information structures.
Members
type
:ImageInfoSpecificKind
block driver name
- The members of
ImageInfoSpecificQCow2Wrapper
whentype
is"qcow2"
- The members of
ImageInfoSpecificVmdkWrapper
whentype
is"vmdk"
- The members of
ImageInfoSpecificLUKSWrapper
whentype
is"luks"
- The members of
ImageInfoSpecificRbdWrapper
whentype
is"rbd"
- The members of
ImageInfoSpecificFileWrapper
whentype
is"file"
Since
1.7
BlockNodeInfo
(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
format-specific
:ImageInfoSpecific
(optional)structure supplying additional format-specific information (since 1.7)
Since
8.0
ImageInfo
(Object)
Information about a QEMU image file, and potentially its backing image
Members
backing-image
:ImageInfo
(optional)info of the backing image
- The members of
BlockNodeInfo
Since
1.3
BlockChildInfo
(Object)
Information about all nodes in the block graph starting at some node, annotated with information about that node in relation to its parent.
Members
name
:string
Child name of the root node in the BlockGraphInfo struct, in its role as the child of some undescribed parent node
info
:BlockGraphInfo
Block graph information starting at this node
Since
8.0
BlockGraphInfo
(Object)
Information about all nodes in a block (sub)graph in the form of BlockNodeInfo data. The base BlockNodeInfo struct contains the information for the (sub)graph’s root node.
Members
children
:array of BlockChildInfo
Array of links to this node’s child nodes’ information
- The members of
BlockNodeInfo
Since
8.0
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
compressed
:boolean
true if the data is stored compressed (since 8.2)
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
present
:boolean
true if this layer provides the data, false if adding a backing layer could impact this region (since 6.1)
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)dirty bitmaps information (only present if node has one or more dirty bitmaps) (Since 4.2)
Since
0.14
BlockDeviceIoStatus
(Enum)
An enumeration of block device I/O status.
Values
ok
The last I/O operation has succeeded
failed
The last I/O operation has failed
nospace
The last I/O operation has failed due to a no-space condition
Since
1.0
BlockDirtyInfo
(Object)
Block dirty bitmap information.
Members
name
:string
(optional)the name of the dirty bitmap (Since 2.4)
count
:int
number of dirty bytes according to the dirty bitmap
granularity
:int
granularity of the dirty bitmap in bytes (since 1.4)
recording
:boolean
true if the bitmap is recording new writes from the guest. (since 4.0)
busy
:boolean
true if the bitmap is in-use by some operation (NBD or jobs) and cannot be modified via QMP or used by another operation. (since 4.0)
persistent
:boolean
true if the bitmap was stored on disk, is scheduled to be stored on disk, or both. (since 4.0)
inconsistent
:boolean
(optional)true if this is a persistent bitmap that was improperly stored. Implies
persistent
to be true;recording
andbusy
to be false. This bitmap cannot be used. To remove it, useblock-dirty-bitmap-remove
. (Since 4.0)
Since
1.3
Qcow2BitmapInfoFlags
(Enum)
An enumeration of flags that a bitmap can report to the user.
Values
in-use
This flag is set by any process actively modifying the qcow2 file, and cleared when the updated bitmap is flushed to the qcow2 image. The presence of this flag in an offline image means that the bitmap was not saved correctly after its last usage, and may contain inconsistent data.
auto
The bitmap must reflect all changes of the virtual disk by any application that would write to this qcow2 file.
Since
4.0
Qcow2BitmapInfo
(Object)
Qcow2 bitmap information.
Members
name
:string
the name of the bitmap
granularity
:int
granularity of the bitmap in bytes
flags
:array of Qcow2BitmapInfoFlags
flags of the bitmap
Since
4.0
BlockLatencyHistogramInfo
(Object)
Block latency histogram.
Members
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, one more element than
boundaries
has. For the example above,bins
may be something like [3, 1, 5, 2], and corresponding histogram looks like:5| * 4| * 3| * * 2| * * * 1| * * * * +------------------ 10 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)
Since
2.10
query-block
(Command)
Get a list of BlockInfo for all virtual block devices.
Returns
a list of BlockInfo
describing each virtual block device.
Filter nodes that were created implicitly are skipped over.
Since
0.14
Example:
-> { "execute": "query-block" }
<- {
"return":[
{
"io-status": "ok",
"device":"ide0-hd0",
"locked":false,
"removable":false,
"inserted":{
"ro":false,
"drv":"qcow2",
"encrypted":false,
"file":"disks/test.qcow2",
"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,
"detect_zeroes": "on",
"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
}
}
},
"qdev": "ide_disk",
"type":"unknown"
},
{
"io-status": "ok",
"device":"ide1-cd0",
"locked":false,
"removable":true,
"qdev": "/machine/unattached/device[23]",
"tray_open": false,
"type":"unknown"
},
{
"device":"floppy0",
"locked":false,
"removable":true,
"qdev": "/machine/unattached/device[20]",
"type":"unknown"
},
{
"device":"sd0",
"locked":false,
"removable":true,
"type":"unknown"
}
]
}
BlockDeviceTimedStats
(Object)
Statistics of a block device during a given interval of time.
Members
interval_length
:int
Interval used for calculating the statistics, in seconds.
min_rd_latency_ns
:int
Minimum latency of read operations in the defined interval, in nanoseconds.
min_wr_latency_ns
:int
Minimum latency of write operations in the defined interval, in nanoseconds.
min_zone_append_latency_ns
:int
Minimum latency of zone append operations in the defined interval, in nanoseconds (since 8.1)
min_flush_latency_ns
:int
Minimum latency of flush operations in the defined interval, in nanoseconds.
max_rd_latency_ns
:int
Maximum latency of read operations in the defined interval, in nanoseconds.
max_wr_latency_ns
:int
Maximum latency of write operations in the defined interval, in nanoseconds.
max_zone_append_latency_ns
:int
Maximum latency of zone append operations in the defined interval, in nanoseconds (since 8.1)
max_flush_latency_ns
:int
Maximum latency of flush operations in the defined interval, in nanoseconds.
avg_rd_latency_ns
:int
Average latency of read operations in the defined interval, in nanoseconds.
avg_wr_latency_ns
:int
Average latency of write operations in the defined interval, in nanoseconds.
avg_zone_append_latency_ns
:int
Average latency of zone append operations in the defined interval, in nanoseconds (since 8.1)
avg_flush_latency_ns
:int
Average latency of flush operations in the defined interval, in nanoseconds.
avg_rd_queue_depth
:number
Average number of pending read operations in the defined interval.
avg_wr_queue_depth
:number
Average number of pending write operations in the defined interval.
avg_zone_append_queue_depth
:number
Average number of pending zone append operations in the defined interval (since 8.1).
Since
2.5
BlockDeviceStats
(Object)
Statistics of a virtual block device or a block backing device.
Members
rd_bytes
:int
The number of bytes read by the device.
wr_bytes
:int
The number of bytes written by the device.
zone_append_bytes
:int
The number of bytes appended by the zoned devices (since 8.1)
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.
zone_append_operations
:int
The number of zone append operations performed by the zoned devices (since 8.1)
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).
zone_append_total_time_ns
:int
Total time spent on zone append writes in nanoseconds (since 8.1)
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).
zone_append_merged
:int
Number of zone append requests that have been merged into another request (since 8.1)
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_zone_append_operations
:int
The number of failed zone append write operations performed by the zoned devices (since 8.1)
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_zone_append_operations
:int
The number of invalid zone append operations performed by the zoned device (since 8.1)
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)zone_append_latency_histogram
:BlockLatencyHistogramInfo
(optional)BlockLatencyHistogramInfo
. (since 8.1)flush_latency_histogram
:BlockLatencyHistogramInfo
(optional)BlockLatencyHistogramInfo
. (Since 4.0)
Since
0.14
BlockStatsSpecificFile
(Object)
File driver statistics
Members
discard-nb-ok
:int
The number of successful discard operations performed by the driver.
discard-nb-failed
:int
The number of failed discard operations performed by the driver.
discard-bytes-ok
:int
The number of bytes discarded by the driver.
Since
4.2
BlockStatsSpecificNvme
(Object)
NVMe driver statistics
Members
completion-errors
:int
The number of completion errors.
aligned-accesses
:int
The number of aligned accesses performed by the driver.
unaligned-accesses
:int
The number of unaligned accesses performed by the driver.
Since
5.2
BlockStatsSpecific
(Object)
Block driver specific statistics
Members
driver
:BlockdevDriver
block driver name
- The members of
BlockStatsSpecificFile
whendriver
is"file"
- The members of
BlockStatsSpecificFile
whendriver
is"host_device"
(If:HAVE_HOST_BLOCK_DEVICE
) - The members of
BlockStatsSpecificNvme
whendriver
is"nvme"
Since
4.2
BlockStats
(Object)
Statistics of a virtual block device or a block backing device.
Members
device
:string
(optional)If the stats are for a virtual block device, the name corresponding to the virtual block device.
node-name
:string
(optional)The node name of the device. (Since 2.3)
qdev
:string
(optional)The qdev ID, or if no ID is assigned, the QOM path of the block device. (since 3.0)
stats
:BlockDeviceStats
A
BlockDeviceStats
for the device.driver-specific
:BlockStatsSpecific
(optional)Optional driver-specific stats. (Since 4.2)
parent
:BlockStats
(optional)This describes the file block device if it has one. Contains recursively the statistics of the underlying protocol (e.g. the host file for a qcow2 image). If there is no underlying protocol, this field is omitted
backing
:BlockStats
(optional)This describes the backing block device if it has one. (Since 2.0)
Since
0.14
query-blockstats
(Command)
Query the BlockStats
for all virtual block devices.
Arguments
query-nodes
:boolean
(optional)If true, the command will query all the block nodes that have a node name, in a list which will include “parent” information, but not “backing”. If false or omitted, the behavior is as before - query all the device backends, recursively including their “parent” and “backing”. Filter nodes that were created implicitly are skipped over in this mode. (Since 2.3)
Returns
A list of BlockStats
for each virtual block devices.
Since
0.14
Example:
-> { "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 asreport
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
BlockJobInfoMirror
(Object)
Information specific to mirror block jobs.
Members
actively-synced
:boolean
Whether the source is actively synced to the target, i.e. same data and new writes are done synchronously to both.
Since
8.2
BlockJobInfo
(Object)
Information about a long-running block device operation.
Members
type
:JobType
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
tolen
. 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)
- The members of
BlockJobInfoMirror
whentype
is"mirror"
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
Errors
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)discard-source
:boolean
(optional)Discard blocks on source which have already been copied to the target. (Since 9.1)
x-perf
:BackupPerf
(optional)Performance options. (Since 6.0)
Features
unstable
Member
x-perf
is experimental.
Note
on-source-error
and on-target-error
only affect
background I/O. If an error occurs during a guest write request,
the device’s rerror/werror actions will be used.
Since
4.2
DriveBackup
(Object)
Members
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 sourcemode
:NewImageMode
(optional)whether and how QEMU should create a new image, default is ‘absolute-paths’.
- The members of
BackupCommon
Since
1.6
BlockdevBackup
(Object)
Members
target
:string
the device name or node-name of the backup target node.
- The members of
BackupCommon
Since
2.3
blockdev-snapshot-sync
(Command)
Takes a synchronous snapshot of a block device.
Arguments
- The members of
BlockdevSnapshotSync
Errors
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.
Arguments
- The members 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.
Errors
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 acceptedtop-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 acceptedbacking-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)
backing-mask-protocol
:boolean
(optional)If true, replace any protocol mentioned in the ‘backing file format’ with ‘raw’, rather than storing the protocol name as the backing format. Can be used even when no image header will be updated (default false; since 9.0).
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
andtop
are deprecated. Usebase-node
andtop-node
instead.
Errors
If
device
does not exist, DeviceNotFoundAny 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
Features
deprecated
This command is deprecated. Use
blockdev-backup
instead.
Errors
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
Errors
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,
"detect_zeroes":"off",
"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.
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.
Features
unstable
This command is meant for debugging.
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
Errors
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 sourcenode-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
BlockDirtyBitmapOrStr
(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 trackingtarget
:string
name of the destination dirty bitmap
bitmaps
:array of BlockDirtyBitmapOrStr
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.
Arguments
- The members of
BlockDirtyBitmapAdd
Errors
If
node
is not a valid block device or node, DeviceNotFoundIf
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.
Arguments
- The members of
BlockDirtyBitmap
Errors
If
node
is not a valid block device or node, DeviceNotFoundIf
name
is not found, GenericError with an explanationif
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.
Arguments
- The members of
BlockDirtyBitmap
Errors
If
node
is not a valid block device, DeviceNotFoundIf
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.
Arguments
- The members of
BlockDirtyBitmap
Errors
If
node
is not a valid block device, DeviceNotFoundIf
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.
Arguments
- The members of
BlockDirtyBitmap
Errors
If
node
is not a valid block device, DeviceNotFoundIf
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.
Arguments
- The members of
BlockDirtyBitmapMerge
Errors
If
node
is not a valid block device, DeviceNotFoundIf any bitmap in
bitmaps
ortarget
is not found, GenericErrorIf 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.
Arguments
- The members of
BlockDirtyBitmap
Features
unstable
This command is meant for debugging.
Returns
BlockDirtyBitmapSha256
Errors
If
node
is not a valid block device, DeviceNotFoundIf
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)
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 ifbps_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 ifbps_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 ifbps_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 ifiops_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 ifiops_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 ifiops_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. Useid
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.
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
Features
unstable
All members starting with x- are aliases for the same key without x- in the
limits
object. This is not a stable interface and may be removed or changed incompatibly in the future. Uselimits
for a supported stable interface.
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
orbottom
is also set.base-node
:string
(optional)the node name of the backing file. It cannot be set if
base
orbottom
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
orbase-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)
backing-mask-protocol
:boolean
(optional)If true, replace any protocol mentioned in the ‘backing file format’ with ‘raw’, rather than storing the protocol name as the backing format. Can be used even when no image header will be updated (default false; since 9.0).
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)
Errors
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.
Errors
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)
Errors
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.
Errors
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.
Errors
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.
Errors
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.
Since
2.12
block-job-finalize
(Command)
Once a job that has manual=true reaches the pending state, it can be instructed to finalize any graph changes and do any necessary cleanup via this command. 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 job identifier.
Since
2.12
BlockJobChangeOptionsMirror
(Object)
Members
copy-mode
:MirrorCopyMode
Switch to this copy mode. Currently, only the switch from ‘background’ to ‘write-blocking’ is implemented.
Since
8.2
BlockJobChangeOptions
(Object)
Block job options that can be changed after job creation.
Members
id
:string
The job identifier
type
:JobType
The job type
- The members of
BlockJobChangeOptionsMirror
whentype
is"mirror"
Since
8.2
block-job-change
(Command)
Change the block job’s options.
Arguments
- The members of
BlockJobChangeOptions
Since
8.2
BlockdevDiscardOptions
(Enum)
Determines how to handle discard requests.
Values
ignore
Ignore the request
unmap
Forward as an unmap request
Since
2.9
BlockdevDetectZeroesOptions
(Enum)
Describes the operation mode for the automatic conversion of plain zero writes by the OS to driver specific optimized zero write commands.
Values
off
Disabled (default)
on
Enabled
unmap
Enabled and even try to unmap blocks if possible. This requires also that
BlockdevDiscardOptions
is set to unmap for this device.
Since
2.1
BlockdevAioOptions
(Enum)
Selects the AIO backend to handle I/O requests
Values
threads
Use qemu’s thread pool
native
Use native AIO backend (only Linux and Windows)
io_uring
(If:CONFIG_LINUX_IO_URING
)Use linux io_uring (since 5.0)
Since
2.9
BlockdevCacheOptions
(Object)
Includes cache-related options for block devices
Members
direct
:boolean
(optional)enables use of O_DIRECT (bypass the host page cache; default: false)
no-flush
:boolean
(optional)ignore any flush requests for the device (default: false)
Since
2.9
BlockdevDriver
(Enum)
Drivers that are supported in block device operations.
Values
throttle
Since 2.11
nvme
Since 2.12
copy-on-read
Since 3.0
blklogwrites
Since 3.0
blkreplay
Since 4.2
compress
Since 5.0
copy-before-write
Since 6.2
snapshot-access
Since 7.0
blkdebug
Not documented
blkverify
Not documented
bochs
Not documented
cloop
Not documented
dmg
Not documented
file
Not documented
ftp
Not documented
ftps
Not documented
gluster
Not documented
host_cdrom
(If:HAVE_HOST_BLOCK_DEVICE
)Not documented
host_device
(If:HAVE_HOST_BLOCK_DEVICE
)Not documented
http
Not documented
https
Not documented
io_uring
(If:CONFIG_BLKIO
)Not documented
iscsi
Not documented
luks
Not documented
nbd
Not documented
nfs
Not documented
null-aio
Not documented
null-co
Not documented
nvme-io_uring
(If:CONFIG_BLKIO
)Not documented
parallels
Not documented
preallocate
Not documented
qcow
Not documented
qcow2
Not documented
qed
Not documented
quorum
Not documented
raw
Not documented
rbd
Not documented
replication
(If:CONFIG_REPLICATION
)Not documented
ssh
Not documented
vdi
Not documented
vhdx
Not documented
virtio-blk-vfio-pci
(If:CONFIG_BLKIO
)Not documented
virtio-blk-vhost-user
(If:CONFIG_BLKIO
)Not documented
virtio-blk-vhost-vdpa
(If:CONFIG_BLKIO
)Not documented
vmdk
Not documented
vpc
Not documented
vvfat
Not documented
Since
2.9
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)
aio-max-batch
:int
(optional)maximum number of requests to batch together into a single submission in the AIO backend. The smallest value between this and the aio-max-batch value of the IOThread object is chosen. 0 means that the AIO backend will handle it automatically. (default: 0, since 6.2)
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: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.
unstable
Member x-check-cache-dropped is meant for debugging.
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.
Note that the PCI device
must have been unbound from any host
kernel driver before instructing QEMU to add the blockdev.
Since
2.12
BlockdevOptionsVVFAT
(Object)
Driver specific block device options for the vvfat protocol.
Members
dir
:string
directory to be exported as FAT image
fat-type
:int
(optional)FAT type: 12, 16 or 32
floppy
:boolean
(optional)whether to export a floppy image (true) or partitioned hard disk (false; default)
label
:string
(optional)set the volume label, limited to 11 bytes. FAT16 and FAT32 traditionally have some restrictions on labels, which are ignored by most operating systems. Defaults to “QEMU VVFAT”. (since 2.4)
rw
:boolean
(optional)whether to allow write operations (default: false)
Since
2.9
BlockdevOptionsGenericFormat
(Object)
Driver specific block device options for image format that have no option besides their data source.
Members
file
:BlockdevRef
reference to or definition of the data source block device
Since
2.9
BlockdevOptionsLUKS
(Object)
Driver specific block device options for LUKS.
Members
key-secret
:string
(optional)the ID of a QCryptoSecret object providing the decryption key (since 2.6). Mandatory except when doing a metadata-only probe of the image.
header
:BlockdevRef
(optional)block device holding a detached LUKS header. (since 9.0)
- The members of
BlockdevOptionsGenericFormat
Since
2.9
BlockdevOptionsGenericCOWFormat
(Object)
Driver specific block device options for image format that have no option besides their data source and an optional backing file.
Members
backing
:BlockdevRefOrNull
(optional)reference to or definition of the backing file block device, null disables the backing file entirely. Defaults to the backing file stored the image file.
- The members of
BlockdevOptionsGenericFormat
Since
2.9
Qcow2OverlapCheckMode
(Enum)
General overlap check modes.
Values
none
Do not perform any checks
constant
Perform only checks which can be done in constant time and without reading anything from disk
cached
Perform only checks which can be done without reading anything from disk
all
Perform all available overlap checks
Since
2.9
Qcow2OverlapCheckFlags
(Object)
Structure of flags for each metadata structure. Setting a field to ‘true’ makes QEMU guard that Qcow2 format structure against unintended overwriting. See Qcow2 format specification for detailed information on these structures. The default value is chosen according to the template given.
Members
template
:Qcow2OverlapCheckMode
(optional)Specifies a template mode which can be adjusted using the other flags, defaults to ‘cached’
main-header
:boolean
(optional)Qcow2 format header
active-l1
:boolean
(optional)Qcow2 active L1 table
active-l2
:boolean
(optional)Qcow2 active L2 table
refcount-table
:boolean
(optional)Qcow2 refcount table
refcount-block
:boolean
(optional)Qcow2 refcount blocks
snapshot-table
:boolean
(optional)Qcow2 snapshot table
inactive-l1
:boolean
(optional)Qcow2 inactive L1 tables
inactive-l2
:boolean
(optional)Qcow2 inactive L2 tables
bitmap-directory
:boolean
(optional)Qcow2 bitmap directory (since 3.0)
Since
2.9
Qcow2OverlapChecks
(Alternate)
Specifies which metadata structures should be guarded against unintended overwriting.
Members
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
encryption format
- The members of
QCryptoBlockOptionsQCow
whenformat
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
encryption format
- The members of
QCryptoBlockOptionsQCow
whenformat
is"aes"
- The members of
QCryptoBlockOptionsLUKS
whenformat
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
discard-no-unref
:boolean
(optional)when enabled, data clusters will remain preallocated when they are no longer used, e.g. because they are discarded or converted to zero clusters. As usual, whether the old data is discarded or kept on the protocol level (i.e. in the image file) depends on the setting of the pass-discard-request option. Keeping the clusters preallocated prevents qcow2 fragmentation that would otherwise be caused by freeing and re-allocating them later. Besides potential performance degradation, such fragmentation can lead to increased allocation of clusters past the end of the image file, resulting in image files whose file length can grow much larger than their guest disk size would suggest. If image file length is of concern (e.g. when storing qcow2 images directly on block devices), you should consider enabling this option. (since 8.1)
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
sha256
The given hash is an sha256 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
How to check the host key
- The members of
SshHostKeyHash
whenmode
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
, ofopt-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
, ofopt-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)choose read pattern and set to quorum by default (Since 2.2)
Since
2.9
BlockdevOptionsGluster
(Object)
Driver specific block device options for Gluster
Members
volume
:string
name of gluster volume where VM image resides
path
:string
absolute path to image file in gluster volume
server
:array of SocketAddress
gluster servers description
debug
:int
(optional)libgfapi log level (default ‘4’ which is Error) (Since 2.8)
logfile
:string
(optional)libgfapi log file (default /dev/stderr) (Since 2.8)
Since
2.9
BlockdevOptionsIoUring
(Object)
Driver specific block device options for the io_uring backend.
Members
filename
:string
path to the image file
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsNvmeIoUring
(Object)
Driver specific block device options for the nvme-io_uring backend.
Members
path
:string
path to the NVMe namespace’s character device (e.g. /dev/ng0n1).
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsVirtioBlkVfioPci
(Object)
Driver specific block device options for the virtio-blk-vfio-pci backend.
Members
path
:string
path to the PCI device’s sysfs directory (e.g. /sys/bus/pci/devices/0000:00:01.0).
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsVirtioBlkVhostUser
(Object)
Driver specific block device options for the virtio-blk-vhost-user backend.
Members
path
:string
path to the vhost-user UNIX domain socket.
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsVirtioBlkVhostVdpa
(Object)
Driver specific block device options for the virtio-blk-vhost-vdpa backend.
Members
path
:string
path to the vhost-vdpa character device.
Features
fdset
Member
path
supports the special “/dev/fdset/N” path (since 8.1)
Since
7.2
If
CONFIG_BLKIO
IscsiTransport
(Enum)
An enumeration of libiscsi transport types
Values
tcp
Not documented
iser
Not documented
Since
2.9
IscsiHeaderDigest
(Enum)
An enumeration of header digests supported by libiscsi
Values
crc32c
Not documented
none
Not documented
crc32c-none
Not documented
none-crc32c
Not documented
Since
2.9
BlockdevOptionsIscsi
(Object)
Driver specific block device options for iscsi
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.
Since
2.9
RbdAuthMode
(Enum)
Values
cephx
Not documented
none
Not documented
Since
3.0
RbdImageEncryptionFormat
(Enum)
Values
luks-any
Used for opening either luks or luks2 (Since 8.0)
luks
Not documented
luks2
Not documented
Since
6.1
RbdEncryptionOptionsLUKSBase
(Object)
Members
key-secret
:string
ID of a QCryptoSecret object providing a passphrase for unlocking the encryption
Since
6.1
RbdEncryptionCreateOptionsLUKSBase
(Object)
Members
cipher-alg
:QCryptoCipherAlgorithm
(optional)The encryption algorithm
- The members of
RbdEncryptionOptionsLUKSBase
Since
6.1
RbdEncryptionOptionsLUKS
(Object)
Members
- The members of
RbdEncryptionOptionsLUKSBase
Since
6.1
RbdEncryptionOptionsLUKS2
(Object)
Members
- The members of
RbdEncryptionOptionsLUKSBase
Since
6.1
RbdEncryptionOptionsLUKSAny
(Object)
Members
- The members of
RbdEncryptionOptionsLUKSBase
Since
8.0
RbdEncryptionCreateOptionsLUKS
(Object)
Members
- The members of
RbdEncryptionCreateOptionsLUKSBase
Since
6.1
RbdEncryptionCreateOptionsLUKS2
(Object)
Members
- The members of
RbdEncryptionCreateOptionsLUKSBase
Since
6.1
RbdEncryptionOptions
(Object)
Members
format
:RbdImageEncryptionFormat
Encryption format.
parent
:RbdEncryptionOptions
(optional)Parent image encryption options (for cloned images). Can be left unspecified if this cloned image is encrypted using the same format and secret as its parent image (i.e. not explicitly formatted) or if its parent image is not encrypted. (Since 8.0)
- The members of
RbdEncryptionOptionsLUKS
whenformat
is"luks"
- The members of
RbdEncryptionOptionsLUKS2
whenformat
is"luks2"
- The members of
RbdEncryptionOptionsLUKSAny
whenformat
is"luks-any"
Since
6.1
RbdEncryptionCreateOptions
(Object)
Members
format
:RbdImageEncryptionFormat
Encryption format.
- The members of
RbdEncryptionCreateOptionsLUKS
whenformat
is"luks"
- The members of
RbdEncryptionCreateOptionsLUKS2
whenformat
is"luks2"
Since
6.1
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.
encrypt
:RbdEncryptionOptions
(optional)Image encryption options. (Since 6.1)
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.
Since
2.9
If
CONFIG_REPLICATION
BlockdevOptionsReplication
(Object)
Driver specific block device options for replication
Members
mode
:ReplicationMode
the replication mode
top-id
:string
(optional)In secondary mode, node name or device ID of the root node who owns the replication node chain. Must not be given in primary mode.
- The members of
BlockdevOptionsGenericFormat
Since
2.9
If
CONFIG_REPLICATION
NFSTransport
(Enum)
An enumeration of NFS transport types
Values
inet
TCP transport
Since
2.9
NFSServer
(Object)
Captures the address of the socket
Members
type
:NFSTransport
transport type used for NFS (only TCP supported)
host
:string
host address for NFS server
Since
2.9
BlockdevOptionsNfs
(Object)
Driver specific block device option for NFS
Members
server
:NFSServer
host address
path
:string
path of the image on the host
user
:int
(optional)UID value to use when talking to the server (defaults to 65534 on Windows and getuid() on unix)
group
:int
(optional)GID value to use when talking to the server (defaults to 65534 on Windows and getgid() in unix)
tcp-syn-count
:int
(optional)number of SYNs during the session establishment (defaults to libnfs default)
readahead-size
:int
(optional)set the readahead size in bytes (defaults to libnfs default)
page-cache-size
:int
(optional)set the pagecache size in bytes (defaults to libnfs default)
debug
:int
(optional)set the NFS debug level (max 2) (defaults to libnfs default)
Since
2.9
BlockdevOptionsCurlBase
(Object)
Driver specific block device options shared by all protocols supported by the curl backend.
Members
url
:string
URL of the image file
readahead
:int
(optional)Size of the read-ahead cache; must be a multiple of 512 (defaults to 256 kB)
timeout
:int
(optional)Timeout for connections, in seconds (defaults to 5)
username
:string
(optional)Username for authentication (defaults to none)
password-secret
:string
(optional)ID of a QCryptoSecret object providing a password for authentication (defaults to no password)
proxy-username
:string
(optional)Username for proxy authentication (defaults to none)
proxy-password-secret
:string
(optional)ID of a QCryptoSecret object providing a password for proxy authentication (defaults to no password)
Since
2.9
BlockdevOptionsCurlHttp
(Object)
Driver specific block device options for HTTP connections over the curl backend. URLs must start with “http://”.
Members
cookie
:string
(optional)List of cookies to set; format is “name1=content1; name2=content2;” as explained by CURLOPT_COOKIE(3). Defaults to no cookies.
cookie-secret
:string
(optional)ID of a QCryptoSecret object providing the cookie data in a secure way. See
cookie
for the format. (since 2.10)- The members of
BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsCurlHttps
(Object)
Driver specific block device options for HTTPS connections over the curl backend. URLs must start with “https://”.
Members
cookie
:string
(optional)List of cookies to set; format is “name1=content1; name2=content2;” as explained by CURLOPT_COOKIE(3). Defaults to no cookies.
sslverify
:boolean
(optional)Whether to verify the SSL certificate’s validity (defaults to true)
cookie-secret
:string
(optional)ID of a QCryptoSecret object providing the cookie data in a secure way. See
cookie
for the format. (since 2.10)- The members of
BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsCurlFtp
(Object)
Driver specific block device options for FTP connections over the curl backend. URLs must start with “ftp://”.
Members
- The members of
BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsCurlFtps
(Object)
Driver specific block device options for FTPS connections over the curl backend. URLs must start with “ftps://”.
Members
sslverify
:boolean
(optional)Whether to verify the SSL certificate’s validity (defaults to true)
- The members of
BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsNbd
(Object)
Driver specific block device options for NBD.
Members
server
:SocketAddress
NBD server address
export
:string
(optional)export name
tls-creds
:string
(optional)TLS credentials ID
tls-hostname
:string
(optional)TLS hostname override for certificate validation (Since 7.0)
x-dirty-bitmap
:string
(optional)A metadata context name such as “qemu:dirty-bitmap:NAME” or “qemu:allocation-depth” to query in place of the traditional “base:allocation” block status (see NBD_OPT_LIST_META_CONTEXT in the NBD protocol; and yes, naming this option x-context would have made more sense) (since 3.0)
reconnect-delay
:int
(optional)On an unexpected disconnect, the nbd client tries to connect again until succeeding or encountering a serious error. During the first
reconnect-delay
seconds, all requests are paused and will be rerun on a successful reconnect. After that time, any delayed requests and all future requests before a successful reconnect will immediately fail. Default 0 (Since 4.2)open-timeout
:int
(optional)In seconds. If zero, the nbd driver tries the connection only once, and fails to open if the connection fails. If non-zero, the nbd driver will repeat connection attempts until successful or until
open-timeout
seconds have elapsed. Default 0 (Since 7.0)
Features
unstable
Member
x-dirty-bitmap
is experimental.
Since
2.9
BlockdevOptionsRaw
(Object)
Driver specific block device options for the raw driver.
Members
offset
:int
(optional)position where the block device starts
size
:int
(optional)the assumed size of the device
- The members of
BlockdevOptionsGenericFormat
Since
2.9
BlockdevOptionsThrottle
(Object)
Driver specific block device options for the throttle driver
Members
throttle-group
:string
the name of the throttle-group object to use. It must already exist.
file
:BlockdevRef
reference to or definition of the data source block device
Since
2.11
BlockdevOptionsCor
(Object)
Driver specific block device options for the copy-on-read driver.
Members
bottom
:string
(optional)The name of a non-filter node (allocation-bearing layer) that limits the COR operations in the backing chain (inclusive), so that no data below this node will be copied by this filter. If option is absent, the limit is not applied, so that data from all backing layers may be copied.
- The members of
BlockdevOptionsGenericFormat
Since
6.0
OnCbwError
(Enum)
An enumeration of possible behaviors for copy-before-write operation failures.
Values
break-guest-write
report the error to the guest. This way, the guest will not be able to overwrite areas that cannot be backed up, so the backup process remains valid.
break-snapshot
continue guest write. Doing so will make the provided snapshot state invalid and any backup or export process based on it will finally fail.
Since
7.1
BlockdevOptionsCbw
(Object)
Driver specific block device options for the copy-before-write
driver, which does so called copy-before-write operations: when data
is written to the filter, the filter first reads corresponding
blocks from its file child and copies them to target
child. After
successfully copying, the write request is propagated to file child.
If copying fails, the original write request is failed too and no
data is written to file child.
Members
target
:BlockdevRef
The target for copy-before-write operations.
bitmap
:BlockDirtyBitmap
(optional)If specified, copy-before-write filter will do copy-before-write operations only for dirty regions of the bitmap. Bitmap size must be equal to length of file and target child of the filter. Note also, that bitmap is used only to initialize internal bitmap of the process, so further modifications (or removing) of specified bitmap doesn’t influence the filter. (Since 7.0)
on-cbw-error
:OnCbwError
(optional)Behavior on failure of copy-before-write operation. Default is
break-guest-write
. (Since 7.1)cbw-timeout
:int
(optional)Zero means no limit. Non-zero sets the timeout in seconds for copy-before-write operation. When a timeout occurs, the respective copy-before-write operation will fail, and the
on-cbw-error
parameter will decide how this failure is handled. Default 0. (Since 7.1)- The members of
BlockdevOptionsGenericFormat
Since
6.2
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
whendriver
is"blkdebug"
- The members of
BlockdevOptionsBlklogwrites
whendriver
is"blklogwrites"
- The members of
BlockdevOptionsBlkverify
whendriver
is"blkverify"
- The members of
BlockdevOptionsBlkreplay
whendriver
is"blkreplay"
- The members of
BlockdevOptionsGenericFormat
whendriver
is"bochs"
- The members of
BlockdevOptionsGenericFormat
whendriver
is"cloop"
- The members of
BlockdevOptionsGenericFormat
whendriver
is"compress"
- The members of
BlockdevOptionsCbw
whendriver
is"copy-before-write"
- The members of
BlockdevOptionsCor
whendriver
is"copy-on-read"
- The members of
BlockdevOptionsGenericFormat
whendriver
is"dmg"
- The members of
BlockdevOptionsFile
whendriver
is"file"
- The members of
BlockdevOptionsCurlFtp
whendriver
is"ftp"
- The members of
BlockdevOptionsCurlFtps
whendriver
is"ftps"
- The members of
BlockdevOptionsGluster
whendriver
is"gluster"
- The members of
BlockdevOptionsFile
whendriver
is"host_cdrom"
(If:HAVE_HOST_BLOCK_DEVICE
) - The members of
BlockdevOptionsFile
whendriver
is"host_device"
(If:HAVE_HOST_BLOCK_DEVICE
) - The members of
BlockdevOptionsCurlHttp
whendriver
is"http"
- The members of
BlockdevOptionsCurlHttps
whendriver
is"https"
- The members of
BlockdevOptionsIoUring
whendriver
is"io_uring"
(If:CONFIG_BLKIO
) - The members of
BlockdevOptionsIscsi
whendriver
is"iscsi"
- The members of
BlockdevOptionsLUKS
whendriver
is"luks"
- The members of
BlockdevOptionsNbd
whendriver
is"nbd"
- The members of
BlockdevOptionsNfs
whendriver
is"nfs"
- The members of
BlockdevOptionsNull
whendriver
is"null-aio"
- The members of
BlockdevOptionsNull
whendriver
is"null-co"
- The members of
BlockdevOptionsNVMe
whendriver
is"nvme"
- The members of
BlockdevOptionsNvmeIoUring
whendriver
is"nvme-io_uring"
(If:CONFIG_BLKIO
) - The members of
BlockdevOptionsGenericFormat
whendriver
is"parallels"
- The members of
BlockdevOptionsPreallocate
whendriver
is"preallocate"
- The members of
BlockdevOptionsQcow2
whendriver
is"qcow2"
- The members of
BlockdevOptionsQcow
whendriver
is"qcow"
- The members of
BlockdevOptionsGenericCOWFormat
whendriver
is"qed"
- The members of
BlockdevOptionsQuorum
whendriver
is"quorum"
- The members of
BlockdevOptionsRaw
whendriver
is"raw"
- The members of
BlockdevOptionsRbd
whendriver
is"rbd"
- The members of
BlockdevOptionsReplication
whendriver
is"replication"
(If:CONFIG_REPLICATION
) - The members of
BlockdevOptionsGenericFormat
whendriver
is"snapshot-access"
- The members of
BlockdevOptionsSsh
whendriver
is"ssh"
- The members of
BlockdevOptionsThrottle
whendriver
is"throttle"
- The members of
BlockdevOptionsGenericFormat
whendriver
is"vdi"
- The members of
BlockdevOptionsGenericFormat
whendriver
is"vhdx"
- The members of
BlockdevOptionsVirtioBlkVfioPci
whendriver
is"virtio-blk-vfio-pci"
(If:CONFIG_BLKIO
) - The members of
BlockdevOptionsVirtioBlkVhostUser
whendriver
is"virtio-blk-vhost-user"
(If:CONFIG_BLKIO
) - The members of
BlockdevOptionsVirtioBlkVhostVdpa
whendriver
is"virtio-blk-vhost-vdpa"
(If:CONFIG_BLKIO
) - The members of
BlockdevOptionsGenericCOWFormat
whendriver
is"vmdk"
- The members of
BlockdevOptionsGenericFormat
whendriver
is"vpc"
- The members of
BlockdevOptionsVVFAT
whendriver
is"vvfat"
Since
2.9
BlockdevRef
(Alternate)
Reference to a block device.
Members
definition
:BlockdevOptions
defines a new block device inline
reference
:string
references the ID of an existing block device
Since
2.9
BlockdevRefOrNull
(Alternate)
Reference to a block device.
Members
definition
:BlockdevOptions
defines a new block device inline
reference
:string
references the ID of an existing block device. An empty string means that no block device should be referenced. Deprecated; use null instead.
null
:null
No block device should be referenced (since 2.10)
Since
2.9
blockdev-add
(Command)
Creates a new block device.
Arguments
- The members of
BlockdevOptions
Since
2.9
Example:
-> { "execute": "blockdev-add",
"arguments": {
"driver": "qcow2",
"node-name": "test1",
"file": {
"driver": "file",
"filename": "test.qcow2"
}
}
}
<- { "return": {} }
Example:
-> { "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": {} }
blockdev-reopen
(Command)
Reopens one or more block devices 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. All devices in the list are reopened in one transaction, so if one of them fails then the whole transaction is cancelled.
The command receives a list of block devices to reopen. For each
one of them, 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. Option (3) is
supported for file
and backing
, and option (4) for backing
only.
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
options
:array of BlockdevOptions
Not documented
Since
6.1
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 CONFIG_POSIX_FALLOCATE), full (if 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 CONFIG_GLUSTERFS_FALLOCATE), full (if CONFIG_GLUSTERFS_ZEROFILL))
Since
2.12
BlockdevCreateOptionsLUKS
(Object)
Driver specific image creation options for LUKS.
Members
file
:BlockdevRef
(optional)Node to create the image format on, mandatory except when ‘preallocation’ is not requested
header
:BlockdevRef
(optional)Block device holding a detached LUKS header. (since 9.0)
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: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
encrypt
:RbdEncryptionCreateOptions
(optional)Image encryption options. (Since 6.1)
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”.
toolsversion
:string
(optional)VMware guest tools version. Default: “2147483647” (Since 6.2)
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
whendriver
is"file"
- The members of
BlockdevCreateOptionsGluster
whendriver
is"gluster"
- The members of
BlockdevCreateOptionsLUKS
whendriver
is"luks"
- The members of
BlockdevCreateOptionsNfs
whendriver
is"nfs"
- The members of
BlockdevCreateOptionsParallels
whendriver
is"parallels"
- The members of
BlockdevCreateOptionsQcow
whendriver
is"qcow"
- The members of
BlockdevCreateOptionsQcow2
whendriver
is"qcow2"
- The members of
BlockdevCreateOptionsQed
whendriver
is"qed"
- The members of
BlockdevCreateOptionsRbd
whendriver
is"rbd"
- The members of
BlockdevCreateOptionsSsh
whendriver
is"ssh"
- The members of
BlockdevCreateOptionsVdi
whendriver
is"vdi"
- The members of
BlockdevCreateOptionsVhdx
whendriver
is"vhdx"
- The members of
BlockdevCreateOptionsVmdk
whendriver
is"vmdk"
- The members of
BlockdevCreateOptionsVpc
whendriver
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
Members
encrypt
:QCryptoBlockAmendOptions
(optional)Encryption options to be amended
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
whendriver
is"luks"
- The members of
BlockdevAmendOptionsQcow2
whendriver
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)
Features
unstable
This command is experimental.
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": "", "node-name": "drive", "fatal": false,
"msg": "L2 table offset 0x2a2a2a00 unaligned (L1 index: 0)" },
"timestamp": { "seconds": 1648243240, "microseconds": 906060 } }
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",
"reason": "No space left on device" },
"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_PENDING",
"data": { "type": "mirror", "id": "backup_1" },
"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.
Features
unstable
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: 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": {} }
Example: 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
Features
unstable
This command is experimental and intended for test cases that need control over IOThreads only.
Since
2.12
Example: Move a node into an IOThread
-> { "execute": "x-blockdev-set-iothread",
"arguments": { "node-name": "disk1",
"iothread": "iothread0" } }
<- { "return": {} }
Example: 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: Read operation
<- { "event": "QUORUM_REPORT_BAD",
"data": { "node-name": "node0", "sector-num": 345435, "sectors-count": 5,
"type": "read" },
"timestamp": { "seconds": 1344522075, "microseconds": 745528 } }
Example: 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
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.
Arguments
- The members of
BlockdevSnapshotInternal
Errors
If
device
is not a valid block device, GenericErrorIf any snapshot matching
name
exists, orname
is empty, GenericErrorIf the format of the image used does not support it, GenericError
Note
Only some image formats such as qcow2 and rbd support internal snapshots.
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
Errors
If
device
is not a valid block device, GenericErrorIf snapshot not found, GenericError
If the format of the image used does not support it, GenericError
If
id
andname
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
}
}
DummyBlockCoreForceArrays
(Object)
Not used by QMP; hack to let us use BlockGraphInfoList internally
Members
unused-block-graph-info
:array of BlockGraphInfo
Not documented
Since
8.0
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. Useid
instead.
Errors
If
device
is not a valid block device, DeviceNotFound
Note
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 requestif the BlockBackend denoted by
device
does not have a guest device attached to itif 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. Useid
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. Useid
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’
force
:boolean
(optional)if false (the default), an eject request through blockdev-open-tray 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. (since 7.1)
Features
deprecated
Member
device
is deprecated. Useid
instead.
Since
2.5
Example: 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": {} }
Example: 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
Errors
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": {} }
Example:
-> { "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 thenboundaries
.boundaries-write
:array of int
(optional)list of interval boundary values for write latency histogram.
boundaries-zap
:array of int
(optional)list of interval boundary values for zone append write latency histogram.
boundaries-flush
:array of int
(optional)list of interval boundary values for flush latency histogram.
Errors
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. Setting this to 1 also stops the server from advertising multiple client support (since 5.2; default: 100)
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. Setting this to 1 also stops the server from advertising multiple client support (since 5.2; default: 100).
Errors
if the server is already running
Since
1.3
BlockExportOptionsNbdBase
(Object)
An NBD block export (common options shared between nbd-server-add and the NBD branch of block-export-add).
Members
name
:string
(optional)Export name. If unspecified, the
device
parameter is used as the export name. (Since 2.12)description
:string
(optional)Free-form description of the export, up to 4096 bytes. (Since 5.0)
Since
5.0
BlockExportOptionsNbd
(Object)
An NBD block export (distinct options used in the NBD branch of block-export-add).
Members
bitmaps
:array of BlockDirtyBitmapOrStr
(optional)Also export each of the named dirty bitmaps reachable from
device
, so the NBD client can use NBD_OPT_SET_META_CONTEXT with the metadata context name “qemu:dirty-bitmap:BITMAP” to inspect each bitmap. Since 7.1 bitmap may be specified by node/name pair.allocation-depth
:boolean
(optional)Also export the allocation depth map for
device
, so the NBD client can use NBD_OPT_SET_META_CONTEXT with the metadata context name “qemu:allocation-depth” to inspect allocation details. (since 5.2)- The members of
BlockExportOptionsNbdBase
Since
5.2
BlockExportOptionsVhostUserBlk
(Object)
A vhost-user-blk block export.