4 This document describes all commands currently supported by QMP.
6 Most of the time their usage is exactly the same as in the user Monitor, this
7 means that any other document which also describe commands (the manpage,
8 QEMU's manual, etc) can and should be consulted.
10 QMP has two types of commands: regular and query commands. Regular commands
11 usually change the Virtual Machine's state someway, while query commands just
12 return information. The sections below are divided accordingly.
14 It's important to observe that all communication examples are formatted in
15 a reader-friendly way, so that they're easier to understand. However, in real
16 protocol usage, they're emitted as a single line.
18 Also, the following notation is used to denote data flow:
20 -> data issued by the Client
21 <- Server data response
23 Please, refer to the QMP specification (docs/qmp-spec.txt) for detailed
24 information on the Server command and response formats.
26 NOTE: This document is temporary and will be replaced soon.
28 1. Stability Considerations
29 ===========================
31 The current QMP command set (described in this file) may be useful for a
32 number of use cases, however it's limited and several commands have bad
33 defined semantics, specially with regard to command completion.
35 These problems are going to be solved incrementally in the next QEMU releases
36 and we're going to establish a deprecation policy for badly defined commands.
38 If you're planning to adopt QMP, please observe the following:
40 1. The deprecation policy will take effect and be documented soon, please
41 check the documentation of each used command as soon as a new release of
44 2. DO NOT rely on anything which is not explicit documented
46 3. Errors, in special, are not documented. Applications should NOT check
47 for specific errors classes or data (it's strongly recommended to only
48 check for the "error" key)
53 Server's responses in the examples below are always a success response, please
54 refer to the QMP specification for more details on error responses.
59 Eject a removable medium.
63 - "force": force ejection (json-bool, optional)
64 - "device": block device name (deprecated, use @id instead)
65 (json-string, optional)
66 - "id": the name or QOM path of the guest device (json-string, optional)
70 -> { "execute": "eject", "arguments": { "id": "ide0-1-0" } }
73 Note: The "force" argument defaults to false.
82 - "driver": the name of the new device's driver (json-string)
83 - "bus": the device's parent bus (device tree path, json-string, optional)
84 - "id": the device's ID, must be unique (json-string)
89 -> { "execute": "device_add", "arguments": { "driver": "e1000", "id": "net1" } }
94 (1) For detailed information about this command, please refer to the
95 'docs/qdev-device-use.txt' file.
97 (2) It's possible to list device properties by running QEMU with the
98 "-device DEVICE,\?" command-line argument, where DEVICE is the device's name
107 - "index": the CPU's index (json-int)
111 -> { "execute": "cpu", "arguments": { "index": 0 } }
114 Note: CPUs' indexes are obtained with the 'query-cpus' command.
116 xen-load-devices-state
117 ----------------------
119 Load the state of all devices from file. The RAM and the block devices
120 of the VM are not loaded by this command.
124 - "filename": the file to load the state of the devices from as binary
125 data. See xen-save-devices-state.txt for a description of the binary
130 -> { "execute": "xen-load-devices-state",
131 "arguments": { "filename": "/tmp/resume" } }
134 migrate-set-cache-size
135 ----------------------
137 Set cache size to be used by XBZRLE migration, the cache size will be rounded
138 down to the nearest power of 2
142 - "value": cache size in bytes (json-int)
146 -> { "execute": "migrate-set-cache-size", "arguments": { "value": 536870912 } }
149 x-colo-lost-heartbeat
152 Tell COLO that heartbeat is lost, a failover or takeover is needed.
156 -> { "execute": "x-colo-lost-heartbeat" }
162 Query background dump status.
168 -> { "execute": "query-dump" }
169 <- { "return": { "status": "active", "completed": 1024000,
175 Resize a block image while a guest is running.
179 - "device": the device's ID, must be unique (json-string)
180 - "node-name": the node name in the block driver state graph (json-string)
185 -> { "execute": "block_resize", "arguments": { "device": "scratch", "size": 1073741824 } }
191 Copy data from a backing file into a block device.
195 - "job-id": Identifier for the newly-created block job. If omitted,
196 the device name will be used. (json-string, optional)
197 - "device": The device name or node-name of a root node (json-string)
198 - "base": The file name of the backing image above which copying starts.
199 It cannot be set if 'base-node' is also set (json-string, optional)
200 - "base-node": the node name of the backing image above which copying starts.
201 It cannot be set if 'base' is also set.
202 (json-string, optional) (Since 2.8)
203 - "backing-file": The backing file string to write into the active layer. This
204 filename is not validated.
206 If a pathname string is such that it cannot be resolved by
207 QEMU, that means that subsequent QMP or HMP commands must use
208 node-names for the image in question, as filename lookup
211 If not specified, QEMU will automatically determine the
212 backing file string to use, or error out if there is no
213 obvious choice. Care should be taken when specifying the
214 string, to specify a valid filename or protocol.
215 (json-string, optional) (Since 2.1)
216 - "speed": the maximum speed, in bytes per second (json-int, optional)
217 - "on-error": the action to take on an error (default 'report'). 'stop' and
218 'enospc' can only be used if the block device supports io-status.
219 (json-string, optional) (Since 2.1)
223 -> { "execute": "block-stream", "arguments": { "device": "virtio0",
224 "base": "/tmp/master.qcow2" } }
230 Live commit of data from overlay image nodes into backing nodes - i.e., writes
231 data between 'top' and 'base' into 'base'.
235 - "job-id": Identifier for the newly-created block job. If omitted,
236 the device name will be used. (json-string, optional)
237 - "device": The device name or node-name of a root node (json-string)
238 - "base": The file name of the backing image to write data into.
239 If not specified, this is the deepest backing image
240 (json-string, optional)
241 - "top": The file name of the backing image within the image chain,
242 which contains the topmost data to be committed down. If
243 not specified, this is the active layer. (json-string, optional)
245 - backing-file: The backing file string to write into the overlay
246 image of 'top'. If 'top' is the active layer,
247 specifying a backing file string is an error. This
248 filename is not validated.
250 If a pathname string is such that it cannot be
251 resolved by QEMU, that means that subsequent QMP or
252 HMP commands must use node-names for the image in
253 question, as filename lookup methods will fail.
255 If not specified, QEMU will automatically determine
256 the backing file string to use, or error out if
257 there is no obvious choice. Care should be taken
258 when specifying the string, to specify a valid
259 filename or protocol.
260 (json-string, optional) (Since 2.1)
262 If top == base, that is an error.
263 If top == active, the job will not be completed by itself,
264 user needs to complete the job with the block-job-complete
265 command after getting the ready event. (Since 2.0)
267 If the base image is smaller than top, then the base image
268 will be resized to be the same size as top. If top is
269 smaller than the base image, the base will not be
270 truncated. If you want the base image size to match the
271 size of the smaller top, you can safely truncate it
272 yourself once the commit operation successfully completes.
274 - "speed": the maximum speed, in bytes per second (json-int, optional)
279 -> { "execute": "block-commit", "arguments": { "device": "virtio0",
280 "top": "/tmp/snap1.qcow2" } }
286 Start a point-in-time copy of a block device to a new destination. The
287 status of ongoing drive-backup operations can be checked with
288 query-block-jobs where the BlockJobInfo.type field has the value 'backup'.
289 The operation can be stopped before it has completed using the
290 block-job-cancel command.
294 - "job-id": Identifier for the newly-created block job. If omitted,
295 the device name will be used. (json-string, optional)
296 - "device": the device name or node-name of a root node which should be copied.
298 - "target": the target of the new image. If the file exists, or if it is a
299 device, the existing file/device will be used as the new
300 destination. If it does not exist, a new file will be created.
302 - "format": the format of the new destination, default is to probe if 'mode' is
303 'existing', else the format of the source
304 (json-string, optional)
305 - "sync": what parts of the disk image should be copied to the destination;
306 possibilities include "full" for all the disk, "top" for only the sectors
307 allocated in the topmost image, "incremental" for only the dirty sectors in
308 the bitmap, or "none" to only replicate new I/O (MirrorSyncMode).
309 - "bitmap": dirty bitmap name for sync==incremental. Must be present if sync
310 is "incremental", must NOT be present otherwise.
311 - "mode": whether and how QEMU should create a new image
312 (NewImageMode, optional, default 'absolute-paths')
313 - "speed": the maximum speed, in bytes per second (json-int, optional)
314 - "compress": true to compress data, if the target format supports it.
315 (json-bool, optional, default false)
316 - "on-source-error": the action to take on an error on the source, default
317 'report'. 'stop' and 'enospc' can only be used
318 if the block device supports io-status.
319 (BlockdevOnError, optional)
320 - "on-target-error": the action to take on an error on the target, default
321 'report' (no limitations, since this applies to
322 a different block device than device).
323 (BlockdevOnError, optional)
326 -> { "execute": "drive-backup", "arguments": { "device": "drive0",
328 "target": "backup.img" } }
334 The device version of drive-backup: this command takes an existing named device
339 - "job-id": Identifier for the newly-created block job. If omitted,
340 the device name will be used. (json-string, optional)
341 - "device": the device name or node-name of a root node which should be copied.
343 - "target": the name of the backup target device. (json-string)
344 - "sync": what parts of the disk image should be copied to the destination;
345 possibilities include "full" for all the disk, "top" for only the
346 sectors allocated in the topmost image, or "none" to only replicate
347 new I/O (MirrorSyncMode).
348 - "speed": the maximum speed, in bytes per second (json-int, optional)
349 - "compress": true to compress data, if the target format supports it.
350 (json-bool, optional, default false)
351 - "on-source-error": the action to take on an error on the source, default
352 'report'. 'stop' and 'enospc' can only be used
353 if the block device supports io-status.
354 (BlockdevOnError, optional)
355 - "on-target-error": the action to take on an error on the target, default
356 'report' (no limitations, since this applies to
357 a different block device than device).
358 (BlockdevOnError, optional)
361 -> { "execute": "blockdev-backup", "arguments": { "device": "src-id",
363 "target": "tgt-id" } }
366 block-dirty-bitmap-add
367 ----------------------
370 Create a dirty bitmap with a name on the device, and start tracking the writes.
374 - "node": device/node on which to create dirty bitmap (json-string)
375 - "name": name of the new dirty bitmap (json-string)
376 - "granularity": granularity to track writes with (int, optional)
380 -> { "execute": "block-dirty-bitmap-add", "arguments": { "node": "drive0",
381 "name": "bitmap0" } }
384 block-dirty-bitmap-remove
385 -------------------------
388 Stop write tracking and remove the dirty bitmap that was created with
389 block-dirty-bitmap-add.
393 - "node": device/node on which to remove dirty bitmap (json-string)
394 - "name": name of the dirty bitmap to remove (json-string)
398 -> { "execute": "block-dirty-bitmap-remove", "arguments": { "node": "drive0",
399 "name": "bitmap0" } }
402 block-dirty-bitmap-clear
403 ------------------------
406 Reset the dirty bitmap associated with a node so that an incremental backup
407 from this point in time forward will only backup clusters modified after this
412 - "node": device/node on which to remove dirty bitmap (json-string)
413 - "name": name of the dirty bitmap to remove (json-string)
417 -> { "execute": "block-dirty-bitmap-clear", "arguments": { "node": "drive0",
418 "name": "bitmap0" } }
421 blockdev-snapshot-sync
422 ----------------------
424 Synchronous snapshot of a block device. snapshot-file specifies the
425 target of the new image. If the file exists, or if it is a device, the
426 snapshot will be created in the existing file/device. If does not
427 exist, a new file will be created. format specifies the format of the
428 snapshot image, default is qcow2.
432 - "device": device name to snapshot (json-string)
433 - "node-name": graph node name to snapshot (json-string)
434 - "snapshot-file": name of new image file (json-string)
435 - "snapshot-node-name": graph node name of the new snapshot (json-string)
436 - "mode": whether and how QEMU should create the snapshot file
437 (NewImageMode, optional, default "absolute-paths")
438 - "format": format of new image (json-string, optional)
442 -> { "execute": "blockdev-snapshot-sync", "arguments": { "device": "ide-hd0",
444 "/some/place/my-image",
445 "format": "qcow2" } }
452 Create a snapshot, by installing 'node' as the backing image of
453 'overlay'. Additionally, if 'node' is associated with a block
454 device, the block device changes to using 'overlay' as its new active
459 - "node": device that will have a snapshot created (json-string)
460 - "overlay": device that will have 'node' as its backing image (json-string)
464 -> { "execute": "blockdev-add",
465 "arguments": { "driver": "qcow2",
466 "node-name": "node1534",
467 "file": { "driver": "file",
468 "filename": "hd1.qcow2" },
473 -> { "execute": "blockdev-snapshot", "arguments": { "node": "ide-hd0",
474 "overlay": "node1534" } }
477 blockdev-snapshot-internal-sync
478 -------------------------------
480 Synchronously take an internal snapshot of a block device when the format of
481 image used supports it. If the name is an empty string, or a snapshot with
482 name already exists, the operation will fail.
486 - "device": the device name or node-name of a root node to snapshot
488 - "name": name of the new snapshot (json-string)
492 -> { "execute": "blockdev-snapshot-internal-sync",
493 "arguments": { "device": "ide-hd0",
494 "name": "snapshot0" }
498 blockdev-snapshot-delete-internal-sync
499 --------------------------------------
501 Synchronously delete an internal snapshot of a block device when the format of
502 image used supports it. The snapshot is identified by name or id or both. One
503 of name or id is required. If the snapshot is not found, the operation will
508 - "device": the device name or node-name of a root node (json-string)
509 - "id": ID of the snapshot (json-string, optional)
510 - "name": name of the snapshot (json-string, optional)
514 -> { "execute": "blockdev-snapshot-delete-internal-sync",
515 "arguments": { "device": "ide-hd0",
516 "name": "snapshot0" }
532 Start mirroring a block device's writes to a new destination. target
533 specifies the target of the new image. If the file exists, or if it is
534 a device, it will be used as the new destination for writes. If it does not
535 exist, a new file will be created. format specifies the format of the
536 mirror image, default is to probe if mode='existing', else the format
541 - "job-id": Identifier for the newly-created block job. If omitted,
542 the device name will be used. (json-string, optional)
543 - "device": the device name or node-name of a root node whose writes should be
544 mirrored. (json-string)
545 - "target": name of new image file (json-string)
546 - "format": format of new image (json-string, optional)
547 - "node-name": the name of the new block driver state in the node graph
548 (json-string, optional)
549 - "replaces": the block driver node name to replace when finished
550 (json-string, optional)
551 - "mode": how an image file should be created into the target
552 file/device (NewImageMode, optional, default 'absolute-paths')
553 - "speed": maximum speed of the streaming job, in bytes per second
555 - "granularity": granularity of the dirty bitmap, in bytes (json-int, optional)
556 - "buf-size": maximum amount of data in flight from source to target, in bytes
557 (json-int, default 10M)
558 - "sync": what parts of the disk image should be copied to the destination;
559 possibilities include "full" for all the disk, "top" for only the sectors
560 allocated in the topmost image, or "none" to only replicate new I/O
562 - "on-source-error": the action to take on an error on the source
563 (BlockdevOnError, default 'report')
564 - "on-target-error": the action to take on an error on the target
565 (BlockdevOnError, default 'report')
566 - "unmap": whether the target sectors should be discarded where source has only
567 zeroes. (json-bool, optional, default true)
569 The default value of the granularity is the image cluster size clamped
570 between 4096 and 65536, if the image format defines one. If the format
571 does not define a cluster size, the default value of the granularity
577 -> { "execute": "drive-mirror", "arguments": { "device": "ide-hd0",
578 "target": "/some/place/my-image",
580 "format": "qcow2" } }
586 Start mirroring a block device's writes to another block device. target
587 specifies the target of mirror operation.
591 - "job-id": Identifier for the newly-created block job. If omitted,
592 the device name will be used. (json-string, optional)
593 - "device": The device name or node-name of a root node whose writes should be
594 mirrored (json-string)
595 - "target": device name to mirror to (json-string)
596 - "replaces": the block driver node name to replace when finished
597 (json-string, optional)
598 - "speed": maximum speed of the streaming job, in bytes per second
600 - "granularity": granularity of the dirty bitmap, in bytes (json-int, optional)
601 - "buf_size": maximum amount of data in flight from source to target, in bytes
602 (json-int, default 10M)
603 - "sync": what parts of the disk image should be copied to the destination;
604 possibilities include "full" for all the disk, "top" for only the sectors
605 allocated in the topmost image, or "none" to only replicate new I/O
607 - "on-source-error": the action to take on an error on the source
608 (BlockdevOnError, default 'report')
609 - "on-target-error": the action to take on an error on the target
610 (BlockdevOnError, default 'report')
612 The default value of the granularity is the image cluster size clamped
613 between 4096 and 65536, if the image format defines one. If the format
614 does not define a cluster size, the default value of the granularity
619 -> { "execute": "blockdev-mirror", "arguments": { "device": "ide-hd0",
628 Change the backing file in the image file metadata. This does not cause
629 QEMU to reopen the image file to reparse the backing filename (it may,
630 however, perform a reopen to change permissions from r/o -> r/w -> r/o,
631 if needed). The new backing file string is written into the image file
632 metadata, and the QEMU internal strings are updated.
636 - "image-node-name": The name of the block driver state node of the
637 image to modify. The "device" is argument is used to
638 verify "image-node-name" is in the chain described by
640 (json-string, optional)
642 - "device": The device name or node-name of the root node that owns
646 - "backing-file": The string to write as the backing file. This string is
647 not validated, so care should be taken when specifying
648 the string or the image chain may not be able to be
652 Returns: Nothing on success
653 If "device" does not exist or cannot be determined, DeviceNotFound
655 block_set_io_throttle
658 Change I/O throttle limits for a block drive.
662 - "device": block device name (deprecated, use @id instead)
663 (json-string, optional)
664 - "id": the name or QOM path of the guest device (json-string, optional)
665 - "bps": total throughput limit in bytes per second (json-int)
666 - "bps_rd": read throughput limit in bytes per second (json-int)
667 - "bps_wr": write throughput limit in bytes per second (json-int)
668 - "iops": total I/O operations per second (json-int)
669 - "iops_rd": read I/O operations per second (json-int)
670 - "iops_wr": write I/O operations per second (json-int)
671 - "bps_max": total throughput limit during bursts, in bytes (json-int, optional)
672 - "bps_rd_max": read throughput limit during bursts, in bytes (json-int, optional)
673 - "bps_wr_max": write throughput limit during bursts, in bytes (json-int, optional)
674 - "iops_max": total I/O operations per second during bursts (json-int, optional)
675 - "iops_rd_max": read I/O operations per second during bursts (json-int, optional)
676 - "iops_wr_max": write I/O operations per second during bursts (json-int, optional)
677 - "bps_max_length": maximum length of the @bps_max burst period, in seconds (json-int, optional)
678 - "bps_rd_max_length": maximum length of the @bps_rd_max burst period, in seconds (json-int, optional)
679 - "bps_wr_max_length": maximum length of the @bps_wr_max burst period, in seconds (json-int, optional)
680 - "iops_max_length": maximum length of the @iops_max burst period, in seconds (json-int, optional)
681 - "iops_rd_max_length": maximum length of the @iops_rd_max burst period, in seconds (json-int, optional)
682 - "iops_wr_max_length": maximum length of the @iops_wr_max burst period, in seconds (json-int, optional)
683 - "iops_size": I/O size in bytes when limiting (json-int, optional)
684 - "group": throttle group name (json-string, optional)
688 -> { "execute": "block_set_io_throttle", "arguments": { "id": "ide0-1-0",
701 "bps_max_length": 60,
708 Enable QMP capabilities.
714 -> { "execute": "qmp_capabilities" }
717 Note: This command must be issued before issuing any other command.
728 Return a json-object with the following information:
730 - "qemu": A json-object containing three integer values:
731 - "major": QEMU's major version (json-int)
732 - "minor": QEMU's minor version (json-int)
733 - "micro": QEMU's micro version (json-int)
734 - "package": package's version (json-string)
738 -> { "execute": "query-version" }
753 List QMP available commands.
755 Each command is represented by a json-object, the returned value is a json-array
758 Each json-object contain:
760 - "name": command's name (json-string)
764 -> { "execute": "query-commands" }
768 "name":"query-balloon"
771 "name":"system_powerdown"
776 Note: This example has been shortened as the real response is too long.
781 Return the QMP wire schema. The returned value is a json-array of
782 named schema entities. Entities are commands, events and various
783 types. See docs/qapi-code-gen.txt for information on their structure
791 This command is still a work in progress. It doesn't support all
792 block drivers among other things. Stay away from it unless you want
793 to help with its development.
795 For the arguments, see the QAPI schema documentation of BlockdevOptions.
799 -> { "execute": "blockdev-add",
800 "arguments": { "driver": "qcow2",
801 "file": { "driver": "file",
802 "filename": "test.qcow2" } } }
807 -> { "execute": "blockdev-add",
810 "node-name": "my_disk",
818 "filename": "/tmp/test.qcow2"
824 "filename": "/dev/fdset/4"
836 Deletes a block device that has been added using blockdev-add.
837 The command will fail if the node is attached to a device or is
838 otherwise being used.
840 This command is still a work in progress and is considered
841 experimental. Stay away from it unless you want to help with its
846 - "node-name": Name of the graph node to delete (json-string)
850 -> { "execute": "blockdev-add",
853 "node-name": "node0",
856 "filename": "test.qcow2"
863 -> { "execute": "x-blockdev-del",
864 "arguments": { "node-name": "node0" }
871 Opens a block device's tray. If there is a block driver state tree inserted as a
872 medium, it will become inaccessible to the guest (but it will remain associated
873 to the block device, so closing the tray will make it accessible again).
875 If the tray was already open before, this will be a no-op.
877 Once the tray opens, a DEVICE_TRAY_MOVED event is emitted. There are cases in
878 which no such event will be generated, these include:
879 - if the guest has locked the tray, @force is false and the guest does not
880 respond to the eject request
881 - if the BlockBackend denoted by @device does not have a guest device attached
883 - if the guest device does not have an actual tray and is empty, for instance
884 for floppy disk drives
888 - "device": block device name (deprecated, use @id instead)
889 (json-string, optional)
890 - "id": the name or QOM path of the guest device (json-string, optional)
891 - "force": if false (the default), an eject request will be sent to the guest if
892 it has locked the tray (and the tray will not be opened immediately);
893 if true, the tray will be opened regardless of whether it is locked
894 (json-bool, optional)
898 -> { "execute": "blockdev-open-tray",
899 "arguments": { "id": "ide0-1-0" } }
901 <- { "timestamp": { "seconds": 1418751016,
902 "microseconds": 716996 },
903 "event": "DEVICE_TRAY_MOVED",
904 "data": { "device": "ide1-cd0",
906 "tray-open": true } }
913 Closes a block device's tray. If there is a block driver state tree associated
914 with the block device (which is currently ejected), that tree will be loaded as
917 If the tray was already closed before, this will be a no-op.
921 - "device": block device name (deprecated, use @id instead)
922 (json-string, optional)
923 - "id": the name or QOM path of the guest device (json-string, optional)
927 -> { "execute": "blockdev-close-tray",
928 "arguments": { "id": "ide0-1-0" } }
930 <- { "timestamp": { "seconds": 1418751345,
931 "microseconds": 272147 },
932 "event": "DEVICE_TRAY_MOVED",
933 "data": { "device": "ide1-cd0",
935 "tray-open": false } }
939 x-blockdev-remove-medium
940 ------------------------
942 Removes a medium (a block driver state tree) from a block device. That block
943 device's tray must currently be open (unless there is no attached guest device).
945 If the tray is open and there is no medium inserted, this will be a no-op.
947 This command is still a work in progress and is considered experimental.
948 Stay away from it unless you want to help with its development.
952 - "device": block device name (deprecated, use @id instead)
953 (json-string, optional)
954 - "id": the name or QOM path of the guest device (json-string, optional)
958 -> { "execute": "x-blockdev-remove-medium",
959 "arguments": { "id": "ide0-1-0" } }
961 <- { "error": { "class": "GenericError",
962 "desc": "Tray of device 'ide0-1-0' is not open" } }
964 -> { "execute": "blockdev-open-tray",
965 "arguments": { "id": "ide0-1-0" } }
967 <- { "timestamp": { "seconds": 1418751627,
968 "microseconds": 549958 },
969 "event": "DEVICE_TRAY_MOVED",
970 "data": { "device": "ide1-cd0",
972 "tray-open": true } }
976 -> { "execute": "x-blockdev-remove-medium",
977 "arguments": { "device": "ide0-1-0" } }
981 x-blockdev-insert-medium
982 ------------------------
984 Inserts a medium (a block driver state tree) into a block device. That block
985 device's tray must currently be open (unless there is no attached guest device)
986 and there must be no medium inserted already.
988 This command is still a work in progress and is considered experimental.
989 Stay away from it unless you want to help with its development.
993 - "device": block device name (deprecated, use @id instead)
994 (json-string, optional)
995 - "id": the name or QOM path of the guest device (json-string, optional)
996 - "node-name": root node of the BDS tree to insert into the block device
1000 -> { "execute": "blockdev-add",
1001 "arguments": { { "node-name": "node0",
1003 "file": { "driver": "file",
1004 "filename": "fedora.iso" } } }
1008 -> { "execute": "x-blockdev-insert-medium",
1009 "arguments": { "id": "ide0-1-0",
1010 "node-name": "node0" } }
1017 Dynamically reconfigure the block driver state graph. It can be used
1018 to add, remove, insert or replace a graph node. Currently only the
1019 Quorum driver implements this feature to add or remove its child. This
1020 is useful to fix a broken quorum child.
1022 If @node is specified, it will be inserted under @parent. @child
1023 may not be specified in this case. If both @parent and @child are
1024 specified but @node is not, @child will be detached from @parent.
1027 - "parent": the id or name of the parent node (json-string)
1028 - "child": the name of a child under the given parent node (json-string, optional)
1029 - "node": the name of the node that will be added (json-string, optional)
1031 Note: this command is experimental, and not a stable API. It doesn't
1032 support all kinds of operations, all kinds of children, nor all block
1035 Warning: The data in a new quorum child MUST be consistent with that of
1036 the rest of the array.
1040 Add a new node to a quorum
1041 -> { "execute": "blockdev-add",
1042 "arguments": { "driver": "raw",
1043 "node-name": "new_node",
1044 "file": { "driver": "file",
1045 "filename": "test.raw" } } }
1047 -> { "execute": "x-blockdev-change",
1048 "arguments": { "parent": "disk1",
1049 "node": "new_node" } }
1052 Delete a quorum's node
1053 -> { "execute": "x-blockdev-change",
1054 "arguments": { "parent": "disk1",
1055 "child": "children.1" } }
1058 query-named-block-nodes
1059 -----------------------
1061 Return a list of BlockDeviceInfo for all the named block driver nodes
1065 -> { "execute": "query-named-block-nodes" }
1066 <- { "return": [ { "ro":false,
1069 "file":"disks/test.qcow2",
1070 "node-name": "my-node",
1071 "backing_file_depth":1,
1085 "write_threshold": 0,
1087 "filename":"disks/test.qcow2",
1089 "virtual-size":2048000,
1090 "backing_file":"base.qcow2",
1091 "full-backing-filename":"disks/base.qcow2",
1092 "backing-filename-format":"qcow2",
1096 "name": "snapshot1",
1098 "date-sec": 10000200,
1100 "vm-clock-sec": 206,
1105 "filename":"disks/base.qcow2",
1107 "virtual-size":2048000
1111 blockdev-change-medium
1112 ----------------------
1114 Changes the medium inserted into a block device by ejecting the current medium
1115 and loading a new image file which is inserted as the new medium.
1119 - "device": block device name (deprecated, use @id instead)
1120 (json-string, optional)
1121 - "id": the name or QOM path of the guest device (json-string, optional)
1122 - "filename": filename of the new image (json-string)
1123 - "format": format of the new image (json-string, optional)
1124 - "read-only-mode": new read-only mode (json-string, optional)
1125 - Possible values: "retain" (default), "read-only", "read-write"
1129 1. Change a removable medium
1131 -> { "execute": "blockdev-change-medium",
1132 "arguments": { "id": "ide0-1-0",
1133 "filename": "/srv/images/Fedora-12-x86_64-DVD.iso",
1137 2. Load a read-only medium into a writable drive
1139 -> { "execute": "blockdev-change-medium",
1140 "arguments": { "id": "floppyA",
1141 "filename": "/srv/images/ro.img",
1143 "read-only-mode": "retain" } }
1146 { "class": "GenericError",
1147 "desc": "Could not open '/srv/images/ro.img': Permission denied" } }
1149 -> { "execute": "blockdev-change-medium",
1150 "arguments": { "id": "floppyA",
1151 "filename": "/srv/images/ro.img",
1153 "read-only-mode": "read-only" } }
1157 trace-event-get-state
1158 ---------------------
1160 Query the state of events.
1164 - "name": Event name pattern (json-string).
1165 - "vcpu": The vCPU to query, any vCPU by default (json-int, optional).
1167 An event is returned if:
1168 - its name matches the "name" pattern, and
1169 - if "vcpu" is given, the event has the "vcpu" property.
1171 Therefore, if "vcpu" is given, the operation will only match per-vCPU events,
1172 returning their state on the specified vCPU. Special case: if "name" is an exact
1173 match, "vcpu" is given and the event does not have the "vcpu" property, an error
1178 -> { "execute": "trace-event-get-state", "arguments": { "name": "qemu_memalign" } }
1179 <- { "return": [ { "name": "qemu_memalign", "state": "disabled" } ] }
1181 trace-event-set-state
1182 ---------------------
1184 Set the state of events.
1188 - "name": Event name pattern (json-string).
1189 - "enable": Whether to enable or disable the event (json-bool).
1190 - "ignore-unavailable": Whether to ignore errors for events that cannot be
1191 changed (json-bool, optional).
1192 - "vcpu": The vCPU to act upon, all vCPUs by default (json-int, optional).
1194 An event's state is modified if:
1195 - its name matches the "name" pattern, and
1196 - if "vcpu" is given, the event has the "vcpu" property.
1198 Therefore, if "vcpu" is given, the operation will only match per-vCPU events,
1199 setting their state on the specified vCPU. Special case: if "name" is an exact
1200 match, "vcpu" is given and the event does not have the "vcpu" property, an error
1205 -> { "execute": "trace-event-set-state", "arguments": { "name": "qemu_memalign", "enable": "true" } }
1208 block-set-write-threshold
1211 Change the write threshold for a block drive. The threshold is an offset,
1212 thus must be non-negative. Default is no write threshold.
1213 Setting the threshold to zero disables it.
1217 - "node-name": the node name in the block driver state graph (json-string)
1218 - "write-threshold": the write threshold in bytes (json-int)
1222 -> { "execute": "block-set-write-threshold",
1223 "arguments": { "node-name": "mydev",
1224 "write-threshold": 17179869184 } }
1232 - "name": switch name
1236 -> { "execute": "query-rocker", "arguments": { "name": "sw1" } }
1237 <- { "return": {"name": "sw1", "ports": 2, "id": 1327446905938}}
1239 Show rocker switch ports
1240 ------------------------
1244 - "name": switch name
1248 -> { "execute": "query-rocker-ports", "arguments": { "name": "sw1" } }
1249 <- { "return": [ {"duplex": "full", "enabled": true, "name": "sw1.1",
1250 "autoneg": "off", "link-up": true, "speed": 10000},
1251 {"duplex": "full", "enabled": true, "name": "sw1.2",
1252 "autoneg": "off", "link-up": true, "speed": 10000}
1255 Show rocker switch OF-DPA flow tables
1256 -------------------------------------
1260 - "name": switch name
1261 - "tbl-id": (optional) flow table ID
1265 -> { "execute": "query-rocker-of-dpa-flows", "arguments": { "name": "sw1" } }
1266 <- { "return": [ {"key": {"in-pport": 0, "priority": 1, "tbl-id": 0},
1269 "action": {"goto-tbl": 10},
1270 "mask": {"in-pport": 4294901760}
1275 Show rocker OF-DPA group tables
1276 -------------------------------
1280 - "name": switch name
1281 - "type": (optional) group type
1285 -> { "execute": "query-rocker-of-dpa-groups", "arguments": { "name": "sw1" } }
1286 <- { "return": [ {"type": 0, "out-pport": 2, "pport": 2, "vlan-id": 3841,
1287 "pop-vlan": 1, "id": 251723778},
1288 {"type": 0, "out-pport": 0, "pport": 0, "vlan-id": 3841,
1289 "pop-vlan": 1, "id": 251723776},
1290 {"type": 0, "out-pport": 1, "pport": 1, "vlan-id": 3840,
1291 "pop-vlan": 1, "id": 251658241},
1292 {"type": 0, "out-pport": 0, "pport": 0, "vlan-id": 3840,
1293 "pop-vlan": 1, "id": 251658240}
1296 query-gic-capabilities
1299 Return a list of GICCapability objects, describing supported GIC
1300 (Generic Interrupt Controller) versions.
1306 -> { "execute": "query-gic-capabilities" }
1307 <- { "return": [{ "version": 2, "emulated": true, "kernel": false },
1308 { "version": 3, "emulated": false, "kernel": true } ] }
1310 Show existing/possible CPUs
1311 ---------------------------
1315 Example for pseries machine type started with
1316 -smp 2,cores=2,maxcpus=4 -cpu POWER8:
1318 -> { "execute": "query-hotpluggable-cpus" }
1320 { "props": { "core-id": 8 }, "type": "POWER8-spapr-cpu-core",
1322 { "props": { "core-id": 0 }, "type": "POWER8-spapr-cpu-core",
1323 "vcpus-count": 1, "qom-path": "/machine/unattached/device[0]"}
1326 Example for pc machine type started with
1328 -> { "execute": "query-hotpluggable-cpus" }
1331 "type": "qemu64-x86_64-cpu", "vcpus-count": 1,
1332 "props": {"core-id": 0, "socket-id": 1, "thread-id": 0}
1335 "qom-path": "/machine/unattached/device[0]",
1336 "type": "qemu64-x86_64-cpu", "vcpus-count": 1,
1337 "props": {"core-id": 0, "socket-id": 0, "thread-id": 0}