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HXCOMM QMP dispatch table and documentation

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SQMP

                        QMP Supported Commands

                        ----------------------

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:

-> data issued by the Client

<- Server data response

Please, refer to the QMP specification (QMP/qmp-spec.txt) for detailed

information on the Server command and response formats.

NOTE: This document is temporary and will be replaced soon.

1. Stability Considerations

===========================

The current QMP command set (described in this file) may be useful for a

number of use cases, however it's limited and several commands have bad

defined semantics, specially with regard to command completion.

These problems are going to be solved incrementally in the next QEMU releases

and we're going to establish a deprecation policy for badly defined commands.

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

    1. The deprecation policy will take effect and be documented soon, please

       check the documentation of each used command as soon as a new release of

       QEMU is available

    2. DO NOT rely on anything which is not explicit documented

    3. Errors, in special, are not documented. Applications should NOT check

       for specific errors classes or data (it's strongly recommended to only

       check for the "error" key)

2. Regular Commands

===================

Server's responses in the examples below are always a success response, please

refer to the QMP specification for more details on error responses.

EQMP

    {

        .name       = "quit",

        .args_type  = "",

        .mhandler.cmd_new = qmp_marshal_input_quit,

    },

SQMP

quit

----

Quit the emulator.

Arguments: None.

Example:

-> { "execute": "quit" }

<- { "return": {} }

EQMP

    {

        .name       = "eject",

        .args_type  = "force:-f,device:B",

        .mhandler.cmd_new = qmp_marshal_input_eject,

    },

SQMP

eject

-----

Eject a removable medium.

Arguments: 

- force: force ejection (json-bool, optional)

- device: device name (json-string)

Example:

-> { "execute": "eject", "arguments": { "device": "ide1-cd0" } }

<- { "return": {} }

Note: The "force" argument defaults to false.

EQMP

    {

        .name       = "change",

        .args_type  = "device:B,target:F,arg:s?",

        .mhandler.cmd_new = qmp_marshal_input_change,

    },

SQMP

change

------

Change a removable medium or VNC configuration.

Arguments:

- "device": device name (json-string)

- "target": filename or item (json-string)

- "arg": additional argument (json-string, optional)

Examples:

1. Change a removable medium

-> { "execute": "change",

             "arguments": { "device": "ide1-cd0",

                            "target": "/srv/images/Fedora-12-x86_64-DVD.iso" } }

<- { "return": {} }

2. Change VNC password

-> { "execute": "change",

             "arguments": { "device": "vnc", "target": "password",

                            "arg": "foobar1" } }

<- { "return": {} }

EQMP

    {

        .name       = "screendump",

        .args_type  = "filename:F",

        .mhandler.cmd_new = qmp_marshal_input_screendump,

    },

SQMP

screendump

----------

Save screen into PPM image.

Arguments:

- "filename": file path (json-string)

Example:

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

<- { "return": {} }

EQMP

    {

        .name       = "stop",

        .args_type  = "",

        .mhandler.cmd_new = qmp_marshal_input_stop,

    },

SQMP

stop

----

Stop the emulator.

Arguments: None.

Example:

-> { "execute": "stop" }

<- { "return": {} }

EQMP

    {

        .name       = "cont",

        .args_type  = "",

        .mhandler.cmd_new = qmp_marshal_input_cont,

    },

SQMP

cont

----

Resume emulation.

Arguments: None.

Example:

-> { "execute": "cont" }

<- { "return": {} }

EQMP

    {

        .name       = "system_wakeup",

        .args_type  = "",

        .mhandler.cmd_new = qmp_marshal_input_system_wakeup,

    },

SQMP

system_wakeup

-------------

Wakeup guest from suspend.

Arguments: None.

Example:

-> { "execute": "system_wakeup" }

<- { "return": {} }

EQMP

    {

        .name       = "system_reset",

        .args_type  = "",

        .mhandler.cmd_new = qmp_marshal_input_system_reset,

    },

SQMP

system_reset

------------

Reset the system.

Arguments: None.

Example:

-> { "execute": "system_reset" }

<- { "return": {} }

EQMP

    {

        .name       = "system_powerdown",

        .args_type  = "",

        .mhandler.cmd_new = qmp_marshal_input_system_powerdown,

    },

SQMP

system_powerdown

----------------

Send system power down event.

Arguments: None.

Example:

-> { "execute": "system_powerdown" }

<- { "return": {} }

EQMP

    {

        .name       = "device_add",

        .args_type  = "device:O",

        .params     = "driver[,prop=value][,...]",

        .help       = "add device, like -device on the command line",

        .user_print = monitor_user_noop,

        .mhandler.cmd_new = do_device_add,

    },

SQMP

device_add

----------

Add a device.

Arguments:

- "driver": the name of the new device's driver (json-string)

- "bus": the device's parent bus (device tree path, json-string, optional)

- "id": the device's ID, must be unique (json-string)

- device properties

Example:

-> { "execute": "device_add", "arguments": { "driver": "e1000", "id": "net1" } }

<- { "return": {} }

Notes:

(1) For detailed information about this command, please refer to the

    'docs/qdev-device-use.txt' file.

(2) It's possible to list device properties by running QEMU with the

    "-device DEVICE,\?" command-line argument, where DEVICE is the device's name

EQMP

    {

        .name       = "device_del",

        .args_type  = "id:s",

        .mhandler.cmd_new = qmp_marshal_input_device_del,

    },

SQMP

device_del

----------

Remove a device.

Arguments:

- "id": the device's ID (json-string)

Example:

-> { "execute": "device_del", "arguments": { "id": "net1" } }

<- { "return": {} }

EQMP

    {

        .name       = "send-key",

        .args_type  = "keys:O,hold-time:i?",

        .mhandler.cmd_new = qmp_marshal_input_send_key,

    },

SQMP

send-key

----------

Send keys to VM.

Arguments:

keys array:

    - "key": key sequence (a json-array of key enum values)

- hold-time: time to delay key up events, milliseconds. Defaults to 100

             (json-int, optional)

Example:

-> { "execute": "send-key",

     "arguments": { 'keys': [ 'ctrl', 'alt', 'delete' ] } }

<- { "return": {} }

EQMP

    {

        .name       = "cpu",

        .args_type  = "index:i",

        .mhandler.cmd_new = qmp_marshal_input_cpu,

    },

SQMP

cpu

---

Set the default CPU.

Arguments:

- "index": the CPU's index (json-int)

Example:

-> { "execute": "cpu", "arguments": { "index": 0 } }

<- { "return": {} }

Note: CPUs' indexes are obtained with the 'query-cpus' command.

EQMP

    {

        .name       = "memsave",

        .args_type  = "val:l,size:i,filename:s,cpu:i?",

        .mhandler.cmd_new = qmp_marshal_input_memsave,

    },

SQMP

memsave

-------

Save to disk virtual memory dump starting at 'val' of size 'size'.

Arguments:

- "val": the starting address (json-int)

- "size": the memory size, in bytes (json-int)

- "filename": file path (json-string)

- "cpu": virtual CPU index (json-int, optional)

Example:

-> { "execute": "memsave",

             "arguments": { "val": 10,

                            "size": 100,

                            "filename": "/tmp/virtual-mem-dump" } }

<- { "return": {} }

EQMP

    {

        .name       = "pmemsave",

        .args_type  = "val:l,size:i,filename:s",

        .mhandler.cmd_new = qmp_marshal_input_pmemsave,

    },

SQMP

pmemsave

--------

Save to disk physical memory dump starting at 'val' of size 'size'.

Arguments:

- "val": the starting address (json-int)

- "size": the memory size, in bytes (json-int)

- "filename": file path (json-string)

Example:

-> { "execute": "pmemsave",

             "arguments": { "val": 10,

                            "size": 100,

                            "filename": "/tmp/physical-mem-dump" } }

<- { "return": {} }

EQMP

    {

        .name       = "inject-nmi",

        .args_type  = "",

        .mhandler.cmd_new = qmp_marshal_input_inject_nmi,

    },

SQMP

inject-nmi

----------

Inject an NMI on guest's CPUs.

Arguments: None.

Example:

-> { "execute": "inject-nmi" }

<- { "return": {} }

Note: inject-nmi fails when the guest doesn't support injecting.

      Currently, only x86 guests do.

EQMP

    {

        .name       = "xen-save-devices-state",

        .args_type  = "filename:F",

    .mhandler.cmd_new = qmp_marshal_input_xen_save_devices_state,

    },

SQMP

xen-save-devices-state

-------

Save the state of all devices to file. The RAM and the block devices

of the VM are not saved by this command.

Arguments:

- "filename": the file to save the state of the devices to as binary

data. See xen-save-devices-state.txt for a description of the binary

format.

Example:

-> { "execute": "xen-save-devices-state",

     "arguments": { "filename": "/tmp/save" } }

<- { "return": {} }

EQMP

    {

        .name       = "xen-set-global-dirty-log",

        .args_type  = "enable:b",

        .mhandler.cmd_new = qmp_marshal_input_xen_set_global_dirty_log,

    },

SQMP

xen-set-global-dirty-log

-------

Enable or disable the global dirty log mode.

Arguments:

- "enable": Enable it or disable it.

Example:

-> { "execute": "xen-set-global-dirty-log",

     "arguments": { "enable": true } }

<- { "return": {} }

EQMP

    {

        .name       = "migrate",

        .args_type  = "detach:-d,blk:-b,inc:-i,uri:s",

        .mhandler.cmd_new = qmp_marshal_input_migrate,

    },

SQMP

migrate

-------

Migrate to URI.

Arguments:

- "blk": block migration, full disk copy (json-bool, optional)

- "inc": incremental disk copy (json-bool, optional)

- "uri": Destination URI (json-string)

Example:

-> { "execute": "migrate", "arguments": { "uri": "tcp:0:4446" } }

<- { "return": {} }

Notes:

(1) The 'query-migrate' command should be used to check migration's progress

    and final result (this information is provided by the 'status' member)

(2) All boolean arguments default to false

(3) The user Monitor's "detach" argument is invalid in QMP and should not

    be used

EQMP

    {

        .name       = "migrate_cancel",

        .args_type  = "",

        .mhandler.cmd_new = qmp_marshal_input_migrate_cancel,

    },

SQMP

migrate_cancel

--------------

Cancel the current migration.

Arguments: None.

Example:

-> { "execute": "migrate_cancel" }

<- { "return": {} }

EQMP

{

        .name       = "migrate-set-cache-size",

        .args_type  = "value:o",

        .mhandler.cmd_new = qmp_marshal_input_migrate_set_cache_size,

    },

SQMP

migrate-set-cache-size

---------------------

Set cache size to be used by XBZRLE migration, the cache size will be rounded

down to the nearest power of 2

Arguments:

- "value": cache size in bytes (json-int)

Example:

-> { "execute": "migrate-set-cache-size", "arguments": { "value": 536870912 } }

<- { "return": {} }

EQMP

    {

        .name       = "query-migrate-cache-size",

        .args_type  = "",

        .mhandler.cmd_new = qmp_marshal_input_query_migrate_cache_size,

    },

SQMP

query-migrate-cache-size

---------------------

Show cache size to be used by XBZRLE migration

returns a json-object with the following information:

- "size" : json-int

Example:

-> { "execute": "query-migrate-cache-size" }

<- { "return": 67108864 }

EQMP

    {

        .name       = "migrate_set_speed",

        .args_type  = "value:o",

        .mhandler.cmd_new = qmp_marshal_input_migrate_set_speed,

    },

SQMP

migrate_set_speed

-----------------

Set maximum speed for migrations.

Arguments:

- "value": maximum speed, in bytes per second (json-int)

Example:

-> { "execute": "migrate_set_speed", "arguments": { "value": 1024 } }

<- { "return": {} }

EQMP

    {

        .name       = "migrate_set_downtime",

        .args_type  = "value:T",

        .mhandler.cmd_new = qmp_marshal_input_migrate_set_downtime,

    },

SQMP

migrate_set_downtime

--------------------

Set maximum tolerated downtime (in seconds) for migrations.

Arguments:

- "value": maximum downtime (json-number)

Example:

-> { "execute": "migrate_set_downtime", "arguments": { "value": 0.1 } }

<- { "return": {} }

EQMP

    {

        .name       = "client_migrate_info",

        .args_type  = "protocol:s,hostname:s,port:i?,tls-port:i?,cert-subject:s?",

        .params     = "protocol hostname port tls-port cert-subject",

        .help       = "send migration info to spice/vnc client",

        .user_print = monitor_user_noop,

        .mhandler.cmd_async = client_migrate_info,

        .flags      = MONITOR_CMD_ASYNC,

    },

SQMP

client_migrate_info

------------------

Set the spice/vnc connection info for the migration target.  The spice/vnc

server will ask the spice/vnc client to automatically reconnect using the

new parameters (if specified) once the vm migration finished successfully.

Arguments:

- "protocol":     protocol: "spice" or "vnc" (json-string)

- "hostname":     migration target hostname (json-string)

- "port":         spice/vnc tcp port for plaintext channels (json-int, optional)

- "tls-port":     spice tcp port for tls-secured channels (json-int, optional)

- "cert-subject": server certificate subject (json-string, optional)

Example:

-> { "execute": "client_migrate_info",

     "arguments": { "protocol": "spice",

                    "hostname": "virt42.lab.kraxel.org",

                    "port": 1234 } }

<- { "return": {} }

EQMP

    {

        .name       = "dump-guest-memory",

        .args_type  = "paging:b,protocol:s,begin:i?,end:i?",

        .params     = "-p protocol [begin] [length]",

        .help       = "dump guest memory to file",

        .user_print = monitor_user_noop,

        .mhandler.cmd_new = qmp_marshal_input_dump_guest_memory,

    },

SQMP

dump

Dump guest memory to file. The file can be processed with crash or gdb.

Arguments:

- "paging": do paging to get guest's memory mapping (json-bool)

- "protocol": destination file(started with "file:") or destination file

              descriptor (started with "fd:") (json-string)

- "begin": the starting physical address. It's optional, and should be specified

           with length together (json-int)

- "length": the memory size, in bytes. It's optional, and should be specified

            with begin together (json-int)

Example:

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

<- { "return": {} }

Notes:

(1) All boolean arguments default to false

EQMP

    {

        .name       = "netdev_add",

        .args_type  = "netdev:O",

        .mhandler.cmd_new = qmp_netdev_add,

    },

SQMP

netdev_add

----------

Add host network device.

Arguments:

- "type": the device type, "tap", "user", ... (json-string)

- "id": the device's ID, must be unique (json-string)

- device options

Example:

-> { "execute": "netdev_add", "arguments": { "type": "user", "id": "netdev1" } }

<- { "return": {} }

Note: The supported device options are the same ones supported by the '-net'

      command-line argument, which are listed in the '-help' output or QEMU's

      manual

EQMP

    {

        .name       = "netdev_del",

        .args_type  = "id:s",

        .mhandler.cmd_new = qmp_marshal_input_netdev_del,

    },

SQMP

netdev_del

----------

Remove host network device.

Arguments:

- "id": the device's ID, must be unique (json-string)

Example:

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

<- { "return": {} }

EQMP

    {

        .name       = "block_resize",

        .args_type  = "device:B,size:o",

        .mhandler.cmd_new = qmp_marshal_input_block_resize,

    },

SQMP

block_resize

------------

Resize a block image while a guest is running.

Arguments:

- "device": the device's ID, must be unique (json-string)

- "size": new size

Example:

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

<- { "return": {} }

EQMP

    {

        .name       = "block-stream",

        .args_type  = "device:B,base:s?,speed:o?,on-error:s?",

        .mhandler.cmd_new = qmp_marshal_input_block_stream,

    },

    {

        .name       = "block-commit",

        .args_type  = "device:B,base:s?,top:s,speed:o?",

        .mhandler.cmd_new = qmp_marshal_input_block_commit,

    },

    {

        .name       = "block-job-set-speed",

        .args_type  = "device:B,speed:o",

        .mhandler.cmd_new = qmp_marshal_input_block_job_set_speed,

    },

    {

        .name       = "block-job-cancel",

        .args_type  = "device:B,force:b?",

        .mhandler.cmd_new = qmp_marshal_input_block_job_cancel,

    },

    {

        .name       = "block-job-pause",

        .args_type  = "device:B",

        .mhandler.cmd_new = qmp_marshal_input_block_job_pause,

    },

    {

        .name       = "block-job-resume",

        .args_type  = "device:B",

        .mhandler.cmd_new = qmp_marshal_input_block_job_resume,

    },

    {

        .name       = "block-job-complete",

        .args_type  = "device:B",

        .mhandler.cmd_new = qmp_marshal_input_block_job_complete,

    },

    {

        .name       = "transaction",

        .args_type  = "actions:q",

        .mhandler.cmd_new = qmp_marshal_input_transaction,

    },

SQMP

transaction

-----------

Atomically operate on one or more block devices.  The only supported

operation for now is snapshotting.  If there is any failure performing

any of the operations, all snapshots for the group are abandoned, and

the original disks pre-snapshot attempt are used.

A list of dictionaries is accepted, that contains the actions to be performed.

For snapshots this is the device, the file to use for the new snapshot,

and the format.  The default format, if not specified, is qcow2.

Each new snapshot defaults to being created by QEMU (wiping any

contents if the file already exists), but it is also possible to reuse

an externally-created file.  In the latter case, you should ensure that

the new image file has the same contents as the current one; QEMU cannot

perform any meaningful check.  Typically this is achieved by using the

current image file as the backing file for the new image.

Arguments:

actions array:

    - "type": the operation to perform.  The only supported

      value is "blockdev-snapshot-sync". (json-string)

    - "data": a dictionary.  The contents depend on the value

      of "type".  When "type" is "blockdev-snapshot-sync":

      - "device": device name to snapshot (json-string)

      - "snapshot-file": name of new image file (json-string)

      - "format": format of new image (json-string, optional)

      - "mode": whether and how QEMU should create the snapshot file

        (NewImageMode, optional, default "absolute-paths")

Example:

-> { "execute": "transaction",

     "arguments": { "actions": [

         { 'type': 'blockdev-snapshot-sync', 'data' : { "device": "ide-hd0",

                                         "snapshot-file": "/some/place/my-image",

                                         "format": "qcow2" } },

         { 'type': 'blockdev-snapshot-sync', 'data' : { "device": "ide-hd1",

                                         "snapshot-file": "/some/place/my-image2",

                                         "mode": "existing",

                                         "format": "qcow2" } } ] } }

<- { "return": {} }

EQMP

    {

        .name       = "blockdev-snapshot-sync",

        .args_type  = "device:B,snapshot-file:s,format:s?,mode:s?",

        .mhandler.cmd_new = qmp_marshal_input_blockdev_snapshot_sync,

    },

SQMP

blockdev-snapshot-sync

----------------------

Synchronous snapshot of a block device. snapshot-file specifies the

target of the new image. If the file exists, or if it is a device, the

snapshot will be created in the existing file/device. If does not

exist, a new file will be created. format specifies the format of the

snapshot image, default is qcow2.

Arguments:

- "device": device name to snapshot (json-string)

- "snapshot-file": name of new image file (json-string)

- "mode": whether and how QEMU should create the snapshot file

  (NewImageMode, optional, default "absolute-paths")

- "format": format of new image (json-string, optional)

Example:

-> { "execute": "blockdev-snapshot-sync", "arguments": { "device": "ide-hd0",

                                                         "snapshot-file":

                                                        "/some/place/my-image",

                                                        "format": "qcow2" } }

<- { "return": {} }

EQMP

    {

        .name       = "drive-mirror",

        .args_type  = "sync:s,device:B,target:s,speed:i?,mode:s?,format:s?,"

                      "on-source-error:s?,on-target-error:s?",

        .mhandler.cmd_new = qmp_marshal_input_drive_mirror,

    },

SQMP

drive-mirror

------------

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:

- "device": device name to operate on (json-string)

- "target": name of new image file (json-string)

- "format": format of new image (json-string, optional)

- "mode": how an image file should be created into the target

  file/device (NewImageMode, optional, default 'absolute-paths')

- "speed": maximum speed of the streaming job, in bytes per second

  (json-int)

- "sync": what parts of the disk image should be copied to the destination;

  possibilities include "full" for all the disk, "top" for only the sectors

  allocated in the topmost image, or "none" to only replicate new I/O

  (MirrorSyncMode).

- "on-source-error": the action to take on an error on the source

  (BlockdevOnError, default 'report')

- "on-target-error": the action to take on an error on the target

  (BlockdevOnError, default 'report')

Example:

-> { "execute": "drive-mirror", "arguments": { "device": "ide-hd0",

                                               "target": "/some/place/my-image",

                                               "sync": "full",

                                               "format": "qcow2" } }

<- { "return": {} }

EQMP

    {

        .name       = "balloon",

        .args_type  = "value:M",

        .mhandler.cmd_new = qmp_marshal_input_balloon,

    },