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
658 Set the password of encrypted block devices.
662 - "device": device name (json-string)
663 - "node-name": name in the block driver state graph (json-string)
664 - "password": password (json-string)
668 -> { "execute": "block_passwd", "arguments": { "device": "ide0-hd0",
669 "password": "12345" } }
672 block_set_io_throttle
675 Change I/O throttle limits for a block drive.
679 - "device": block device name (deprecated, use @id instead)
680 (json-string, optional)
681 - "id": the name or QOM path of the guest device (json-string, optional)
682 - "bps": total throughput limit in bytes per second (json-int)
683 - "bps_rd": read throughput limit in bytes per second (json-int)
684 - "bps_wr": write throughput limit in bytes per second (json-int)
685 - "iops": total I/O operations per second (json-int)
686 - "iops_rd": read I/O operations per second (json-int)
687 - "iops_wr": write I/O operations per second (json-int)
688 - "bps_max": total throughput limit during bursts, in bytes (json-int, optional)
689 - "bps_rd_max": read throughput limit during bursts, in bytes (json-int, optional)
690 - "bps_wr_max": write throughput limit during bursts, in bytes (json-int, optional)
691 - "iops_max": total I/O operations per second during bursts (json-int, optional)
692 - "iops_rd_max": read I/O operations per second during bursts (json-int, optional)
693 - "iops_wr_max": write I/O operations per second during bursts (json-int, optional)
694 - "bps_max_length": maximum length of the @bps_max burst period, in seconds (json-int, optional)
695 - "bps_rd_max_length": maximum length of the @bps_rd_max burst period, in seconds (json-int, optional)
696 - "bps_wr_max_length": maximum length of the @bps_wr_max burst period, in seconds (json-int, optional)
697 - "iops_max_length": maximum length of the @iops_max burst period, in seconds (json-int, optional)
698 - "iops_rd_max_length": maximum length of the @iops_rd_max burst period, in seconds (json-int, optional)
699 - "iops_wr_max_length": maximum length of the @iops_wr_max burst period, in seconds (json-int, optional)
700 - "iops_size": I/O size in bytes when limiting (json-int, optional)
701 - "group": throttle group name (json-string, optional)
705 -> { "execute": "block_set_io_throttle", "arguments": { "id": "ide0-1-0",
718 "bps_max_length": 60,
725 Enable QMP capabilities.
731 -> { "execute": "qmp_capabilities" }
734 Note: This command must be issued before issuing any other command.
745 Return a json-object with the following information:
747 - "qemu": A json-object containing three integer values:
748 - "major": QEMU's major version (json-int)
749 - "minor": QEMU's minor version (json-int)
750 - "micro": QEMU's micro version (json-int)
751 - "package": package's version (json-string)
755 -> { "execute": "query-version" }
770 List QMP available commands.
772 Each command is represented by a json-object, the returned value is a json-array
775 Each json-object contain:
777 - "name": command's name (json-string)
781 -> { "execute": "query-commands" }
785 "name":"query-balloon"
788 "name":"system_powerdown"
793 Note: This example has been shortened as the real response is too long.
798 Return the QMP wire schema. The returned value is a json-array of
799 named schema entities. Entities are commands, events and various
800 types. See docs/qapi-code-gen.txt for information on their structure
806 Show the block devices.
808 Each block device information is stored in a json-object and the returned value
809 is a json-array of all devices.
811 Each json-object contain the following:
813 - "device": device name (json-string)
814 - "type": device type (json-string)
815 - deprecated, retained for backward compatibility
816 - Possible values: "unknown"
817 - "removable": true if the device is removable, false otherwise (json-bool)
818 - "locked": true if the device is locked, false otherwise (json-bool)
819 - "tray_open": only present if removable, true if the device has a tray,
820 and it is open (json-bool)
821 - "inserted": only present if the device is inserted, it is a json-object
822 containing the following:
823 - "file": device file name (json-string)
824 - "ro": true if read-only, false otherwise (json-bool)
825 - "drv": driver format name (json-string)
826 - Possible values: "blkdebug", "bochs", "cloop", "dmg",
827 "file", "file", "ftp", "ftps", "host_cdrom",
828 "host_device", "http", "https",
829 "nbd", "parallels", "qcow", "qcow2", "raw",
830 "vdi", "vmdk", "vpc", "vvfat"
831 - "backing_file": backing file name (json-string, optional)
832 - "backing_file_depth": number of files in the backing file chain (json-int)
833 - "encrypted": true if encrypted, false otherwise (json-bool)
834 - "bps": limit total bytes per second (json-int)
835 - "bps_rd": limit read bytes per second (json-int)
836 - "bps_wr": limit write bytes per second (json-int)
837 - "iops": limit total I/O operations per second (json-int)
838 - "iops_rd": limit read operations per second (json-int)
839 - "iops_wr": limit write operations per second (json-int)
840 - "bps_max": total max in bytes (json-int)
841 - "bps_rd_max": read max in bytes (json-int)
842 - "bps_wr_max": write max in bytes (json-int)
843 - "iops_max": total I/O operations max (json-int)
844 - "iops_rd_max": read I/O operations max (json-int)
845 - "iops_wr_max": write I/O operations max (json-int)
846 - "iops_size": I/O size when limiting by iops (json-int)
847 - "detect_zeroes": detect and optimize zero writing (json-string)
848 - Possible values: "off", "on", "unmap"
849 - "write_threshold": write offset threshold in bytes, a event will be
850 emitted if crossed. Zero if disabled (json-int)
851 - "image": the detail of the image, it is a json-object containing
853 - "filename": image file name (json-string)
854 - "format": image format (json-string)
855 - "virtual-size": image capacity in bytes (json-int)
856 - "dirty-flag": true if image is not cleanly closed, not present
857 means clean (json-bool, optional)
858 - "actual-size": actual size on disk in bytes of the image, not
859 present when image does not support thin
860 provision (json-int, optional)
861 - "cluster-size": size of a cluster in bytes, not present if image
862 format does not support it (json-int, optional)
863 - "encrypted": true if the image is encrypted, not present means
864 false or the image format does not support
865 encryption (json-bool, optional)
866 - "backing_file": backing file name, not present means no backing
867 file is used or the image format does not
868 support backing file chain
869 (json-string, optional)
870 - "full-backing-filename": full path of the backing file, not
871 present if it equals backing_file or no
873 (json-string, optional)
874 - "backing-filename-format": the format of the backing file, not
875 present means unknown or no backing
876 file (json-string, optional)
877 - "snapshots": the internal snapshot info, it is an optional list
878 of json-object containing the following:
879 - "id": unique snapshot id (json-string)
880 - "name": snapshot name (json-string)
881 - "vm-state-size": size of the VM state in bytes (json-int)
882 - "date-sec": UTC date of the snapshot in seconds (json-int)
883 - "date-nsec": fractional part in nanoseconds to be used with
885 - "vm-clock-sec": VM clock relative to boot in seconds
887 - "vm-clock-nsec": fractional part in nanoseconds to be used
888 with vm-clock-sec (json-int)
889 - "backing-image": the detail of the backing image, it is an
890 optional json-object only present when a
891 backing image present for this image
893 - "io-status": I/O operation status, only present if the device supports it
894 and the VM is configured to stop on errors. It's always reset
895 to "ok" when the "cont" command is issued (json_string, optional)
896 - Possible values: "ok", "failed", "nospace"
900 -> { "execute": "query-block" }
912 "file":"disks/test.qcow2",
913 "backing_file_depth":1,
927 "detect_zeroes": "on",
928 "write_threshold": 0,
930 "filename":"disks/test.qcow2",
932 "virtual-size":2048000,
933 "backing_file":"base.qcow2",
934 "full-backing-filename":"disks/base.qcow2",
935 "backing-filename-format":"qcow2",
941 "date-sec": 10000200,
948 "filename":"disks/base.qcow2",
950 "virtual-size":2048000
981 Show block device statistics.
983 Each device statistic information is stored in a json-object and the returned
984 value is a json-array of all devices.
986 Each json-object contain the following:
988 - "device": device name (json-string)
989 - "stats": A json-object with the statistics information, it contains:
990 - "rd_bytes": bytes read (json-int)
991 - "wr_bytes": bytes written (json-int)
992 - "rd_operations": read operations (json-int)
993 - "wr_operations": write operations (json-int)
994 - "flush_operations": cache flush operations (json-int)
995 - "wr_total_time_ns": total time spend on writes in nano-seconds (json-int)
996 - "rd_total_time_ns": total time spend on reads in nano-seconds (json-int)
997 - "flush_total_time_ns": total time spend on cache flushes in nano-seconds (json-int)
998 - "wr_highest_offset": The offset after the greatest byte written to the
999 BlockDriverState since it has been opened (json-int)
1000 - "rd_merged": number of read requests that have been merged into
1001 another request (json-int)
1002 - "wr_merged": number of write requests that have been merged into
1003 another request (json-int)
1004 - "idle_time_ns": time since the last I/O operation, in
1005 nanoseconds. If the field is absent it means
1006 that there haven't been any operations yet
1007 (json-int, optional)
1008 - "failed_rd_operations": number of failed read operations
1010 - "failed_wr_operations": number of failed write operations
1012 - "failed_flush_operations": number of failed flush operations
1014 - "invalid_rd_operations": number of invalid read operations
1016 - "invalid_wr_operations": number of invalid write operations
1018 - "invalid_flush_operations": number of invalid flush operations
1020 - "account_invalid": whether invalid operations are included in
1021 the last access statistics (json-bool)
1022 - "account_failed": whether failed operations are included in the
1023 latency and last access statistics
1025 - "timed_stats": A json-array containing statistics collected in
1026 specific intervals, with the following members:
1027 - "interval_length": interval used for calculating the
1028 statistics, in seconds (json-int)
1029 - "min_rd_latency_ns": minimum latency of read operations in
1030 the defined interval, in nanoseconds
1032 - "min_wr_latency_ns": minimum latency of write operations in
1033 the defined interval, in nanoseconds
1035 - "min_flush_latency_ns": minimum latency of flush operations
1036 in the defined interval, in
1037 nanoseconds (json-int)
1038 - "max_rd_latency_ns": maximum latency of read operations in
1039 the defined interval, in nanoseconds
1041 - "max_wr_latency_ns": maximum latency of write operations in
1042 the defined interval, in nanoseconds
1044 - "max_flush_latency_ns": maximum latency of flush operations
1045 in the defined interval, in
1046 nanoseconds (json-int)
1047 - "avg_rd_latency_ns": average latency of read operations in
1048 the defined interval, in nanoseconds
1050 - "avg_wr_latency_ns": average latency of write operations in
1051 the defined interval, in nanoseconds
1053 - "avg_flush_latency_ns": average latency of flush operations
1054 in the defined interval, in
1055 nanoseconds (json-int)
1056 - "avg_rd_queue_depth": average number of pending read
1057 operations in the defined interval
1059 - "avg_wr_queue_depth": average number of pending write
1060 operations in the defined interval
1062 - "parent": Contains recursively the statistics of the underlying
1063 protocol (e.g. the host file for a qcow2 image). If there is
1064 no underlying protocol, this field is omitted
1065 (json-object, optional)
1069 -> { "execute": "query-blockstats" }
1073 "device":"ide0-hd0",
1076 "wr_highest_offset":3686448128,
1078 "wr_operations":751,
1079 "rd_bytes":122567168,
1080 "rd_operations":36772
1081 "wr_total_times_ns":313253456
1082 "rd_total_times_ns":3465673657
1083 "flush_total_times_ns":49653
1084 "flush_operations":61,
1087 "idle_time_ns":2953431879,
1088 "account_invalid":true,
1089 "account_failed":false
1093 "wr_highest_offset":2821110784,
1095 "wr_operations":692,
1096 "rd_bytes":122739200,
1097 "rd_operations":36604
1098 "flush_operations":51,
1099 "wr_total_times_ns":313253456
1100 "rd_total_times_ns":3465673657
1101 "flush_total_times_ns":49653,
1104 "idle_time_ns":2953431879,
1105 "account_invalid":true,
1106 "account_failed":false
1110 "device":"ide1-cd0",
1112 "wr_highest_offset":0,
1117 "flush_operations":0,
1118 "wr_total_times_ns":0
1119 "rd_total_times_ns":0
1120 "flush_total_times_ns":0,
1123 "account_invalid":false,
1124 "account_failed":false
1130 "wr_highest_offset":0,
1135 "flush_operations":0,
1136 "wr_total_times_ns":0
1137 "rd_total_times_ns":0
1138 "flush_total_times_ns":0,
1141 "account_invalid":false,
1142 "account_failed":false
1148 "wr_highest_offset":0,
1153 "flush_operations":0,
1154 "wr_total_times_ns":0
1155 "rd_total_times_ns":0
1156 "flush_total_times_ns":0,
1159 "account_invalid":false,
1160 "account_failed":false
1171 This command is still a work in progress. It doesn't support all
1172 block drivers among other things. Stay away from it unless you want
1173 to help with its development.
1175 For the arguments, see the QAPI schema documentation of BlockdevOptions.
1179 -> { "execute": "blockdev-add",
1180 "arguments": { "driver": "qcow2",
1181 "file": { "driver": "file",
1182 "filename": "test.qcow2" } } }
1187 -> { "execute": "blockdev-add",
1190 "node-name": "my_disk",
1198 "filename": "/tmp/test.qcow2"
1204 "filename": "/dev/fdset/4"
1216 Deletes a block device that has been added using blockdev-add.
1217 The command will fail if the node is attached to a device or is
1218 otherwise being used.
1220 This command is still a work in progress and is considered
1221 experimental. Stay away from it unless you want to help with its
1226 - "node-name": Name of the graph node to delete (json-string)
1230 -> { "execute": "blockdev-add",
1233 "node-name": "node0",
1236 "filename": "test.qcow2"
1243 -> { "execute": "x-blockdev-del",
1244 "arguments": { "node-name": "node0" }
1251 Opens a block device's tray. If there is a block driver state tree inserted as a
1252 medium, it will become inaccessible to the guest (but it will remain associated
1253 to the block device, so closing the tray will make it accessible again).
1255 If the tray was already open before, this will be a no-op.
1257 Once the tray opens, a DEVICE_TRAY_MOVED event is emitted. There are cases in
1258 which no such event will be generated, these include:
1259 - if the guest has locked the tray, @force is false and the guest does not
1260 respond to the eject request
1261 - if the BlockBackend denoted by @device does not have a guest device attached
1263 - if the guest device does not have an actual tray and is empty, for instance
1264 for floppy disk drives
1268 - "device": block device name (deprecated, use @id instead)
1269 (json-string, optional)
1270 - "id": the name or QOM path of the guest device (json-string, optional)
1271 - "force": if false (the default), an eject request will be sent to the guest if
1272 it has locked the tray (and the tray will not be opened immediately);
1273 if true, the tray will be opened regardless of whether it is locked
1274 (json-bool, optional)
1278 -> { "execute": "blockdev-open-tray",
1279 "arguments": { "id": "ide0-1-0" } }
1281 <- { "timestamp": { "seconds": 1418751016,
1282 "microseconds": 716996 },
1283 "event": "DEVICE_TRAY_MOVED",
1284 "data": { "device": "ide1-cd0",
1286 "tray-open": true } }
1293 Closes a block device's tray. If there is a block driver state tree associated
1294 with the block device (which is currently ejected), that tree will be loaded as
1297 If the tray was already closed before, this will be a no-op.
1301 - "device": block device name (deprecated, use @id instead)
1302 (json-string, optional)
1303 - "id": the name or QOM path of the guest device (json-string, optional)
1307 -> { "execute": "blockdev-close-tray",
1308 "arguments": { "id": "ide0-1-0" } }
1310 <- { "timestamp": { "seconds": 1418751345,
1311 "microseconds": 272147 },
1312 "event": "DEVICE_TRAY_MOVED",
1313 "data": { "device": "ide1-cd0",
1315 "tray-open": false } }
1319 x-blockdev-remove-medium
1320 ------------------------
1322 Removes a medium (a block driver state tree) from a block device. That block
1323 device's tray must currently be open (unless there is no attached guest device).
1325 If the tray is open and there is no medium inserted, this will be a no-op.
1327 This command is still a work in progress and is considered experimental.
1328 Stay away from it unless you want to help with its development.
1332 - "device": block device name (deprecated, use @id instead)
1333 (json-string, optional)
1334 - "id": the name or QOM path of the guest device (json-string, optional)
1338 -> { "execute": "x-blockdev-remove-medium",
1339 "arguments": { "id": "ide0-1-0" } }
1341 <- { "error": { "class": "GenericError",
1342 "desc": "Tray of device 'ide0-1-0' is not open" } }
1344 -> { "execute": "blockdev-open-tray",
1345 "arguments": { "id": "ide0-1-0" } }
1347 <- { "timestamp": { "seconds": 1418751627,
1348 "microseconds": 549958 },
1349 "event": "DEVICE_TRAY_MOVED",
1350 "data": { "device": "ide1-cd0",
1352 "tray-open": true } }
1356 -> { "execute": "x-blockdev-remove-medium",
1357 "arguments": { "device": "ide0-1-0" } }
1361 x-blockdev-insert-medium
1362 ------------------------
1364 Inserts a medium (a block driver state tree) into a block device. That block
1365 device's tray must currently be open (unless there is no attached guest device)
1366 and there must be no medium inserted already.
1368 This command is still a work in progress and is considered experimental.
1369 Stay away from it unless you want to help with its development.
1373 - "device": block device name (deprecated, use @id instead)
1374 (json-string, optional)
1375 - "id": the name or QOM path of the guest device (json-string, optional)
1376 - "node-name": root node of the BDS tree to insert into the block device
1380 -> { "execute": "blockdev-add",
1381 "arguments": { { "node-name": "node0",
1383 "file": { "driver": "file",
1384 "filename": "fedora.iso" } } }
1388 -> { "execute": "x-blockdev-insert-medium",
1389 "arguments": { "id": "ide0-1-0",
1390 "node-name": "node0" } }
1397 Dynamically reconfigure the block driver state graph. It can be used
1398 to add, remove, insert or replace a graph node. Currently only the
1399 Quorum driver implements this feature to add or remove its child. This
1400 is useful to fix a broken quorum child.
1402 If @node is specified, it will be inserted under @parent. @child
1403 may not be specified in this case. If both @parent and @child are
1404 specified but @node is not, @child will be detached from @parent.
1407 - "parent": the id or name of the parent node (json-string)
1408 - "child": the name of a child under the given parent node (json-string, optional)
1409 - "node": the name of the node that will be added (json-string, optional)
1411 Note: this command is experimental, and not a stable API. It doesn't
1412 support all kinds of operations, all kinds of children, nor all block
1415 Warning: The data in a new quorum child MUST be consistent with that of
1416 the rest of the array.
1420 Add a new node to a quorum
1421 -> { "execute": "blockdev-add",
1422 "arguments": { "driver": "raw",
1423 "node-name": "new_node",
1424 "file": { "driver": "file",
1425 "filename": "test.raw" } } }
1427 -> { "execute": "x-blockdev-change",
1428 "arguments": { "parent": "disk1",
1429 "node": "new_node" } }
1432 Delete a quorum's node
1433 -> { "execute": "x-blockdev-change",
1434 "arguments": { "parent": "disk1",
1435 "child": "children.1" } }
1438 query-named-block-nodes
1439 -----------------------
1441 Return a list of BlockDeviceInfo for all the named block driver nodes
1445 -> { "execute": "query-named-block-nodes" }
1446 <- { "return": [ { "ro":false,
1449 "file":"disks/test.qcow2",
1450 "node-name": "my-node",
1451 "backing_file_depth":1,
1465 "write_threshold": 0,
1467 "filename":"disks/test.qcow2",
1469 "virtual-size":2048000,
1470 "backing_file":"base.qcow2",
1471 "full-backing-filename":"disks/base.qcow2",
1472 "backing-filename-format":"qcow2",
1476 "name": "snapshot1",
1478 "date-sec": 10000200,
1480 "vm-clock-sec": 206,
1485 "filename":"disks/base.qcow2",
1487 "virtual-size":2048000
1491 blockdev-change-medium
1492 ----------------------
1494 Changes the medium inserted into a block device by ejecting the current medium
1495 and loading a new image file which is inserted as the new medium.
1499 - "device": block device name (deprecated, use @id instead)
1500 (json-string, optional)
1501 - "id": the name or QOM path of the guest device (json-string, optional)
1502 - "filename": filename of the new image (json-string)
1503 - "format": format of the new image (json-string, optional)
1504 - "read-only-mode": new read-only mode (json-string, optional)
1505 - Possible values: "retain" (default), "read-only", "read-write"
1509 1. Change a removable medium
1511 -> { "execute": "blockdev-change-medium",
1512 "arguments": { "id": "ide0-1-0",
1513 "filename": "/srv/images/Fedora-12-x86_64-DVD.iso",
1517 2. Load a read-only medium into a writable drive
1519 -> { "execute": "blockdev-change-medium",
1520 "arguments": { "id": "floppyA",
1521 "filename": "/srv/images/ro.img",
1523 "read-only-mode": "retain" } }
1526 { "class": "GenericError",
1527 "desc": "Could not open '/srv/images/ro.img': Permission denied" } }
1529 -> { "execute": "blockdev-change-medium",
1530 "arguments": { "id": "floppyA",
1531 "filename": "/srv/images/ro.img",
1533 "read-only-mode": "read-only" } }
1537 rtc-reset-reinjection
1538 ---------------------
1540 Reset the RTC interrupt reinjection backlog.
1546 -> { "execute": "rtc-reset-reinjection" }
1549 trace-event-get-state
1550 ---------------------
1552 Query the state of events.
1556 - "name": Event name pattern (json-string).
1557 - "vcpu": The vCPU to query, any vCPU by default (json-int, optional).
1559 An event is returned if:
1560 - its name matches the "name" pattern, and
1561 - if "vcpu" is given, the event has the "vcpu" property.
1563 Therefore, if "vcpu" is given, the operation will only match per-vCPU events,
1564 returning their state on the specified vCPU. Special case: if "name" is an exact
1565 match, "vcpu" is given and the event does not have the "vcpu" property, an error
1570 -> { "execute": "trace-event-get-state", "arguments": { "name": "qemu_memalign" } }
1571 <- { "return": [ { "name": "qemu_memalign", "state": "disabled" } ] }
1573 trace-event-set-state
1574 ---------------------
1576 Set the state of events.
1580 - "name": Event name pattern (json-string).
1581 - "enable": Whether to enable or disable the event (json-bool).
1582 - "ignore-unavailable": Whether to ignore errors for events that cannot be
1583 changed (json-bool, optional).
1584 - "vcpu": The vCPU to act upon, all vCPUs by default (json-int, optional).
1586 An event's state is modified if:
1587 - its name matches the "name" pattern, and
1588 - if "vcpu" is given, the event has the "vcpu" property.
1590 Therefore, if "vcpu" is given, the operation will only match per-vCPU events,
1591 setting their state on the specified vCPU. Special case: if "name" is an exact
1592 match, "vcpu" is given and the event does not have the "vcpu" property, an error
1597 -> { "execute": "trace-event-set-state", "arguments": { "name": "qemu_memalign", "enable": "true" } }
1600 block-set-write-threshold
1603 Change the write threshold for a block drive. The threshold is an offset,
1604 thus must be non-negative. Default is no write threshold.
1605 Setting the threshold to zero disables it.
1609 - "node-name": the node name in the block driver state graph (json-string)
1610 - "write-threshold": the write threshold in bytes (json-int)
1614 -> { "execute": "block-set-write-threshold",
1615 "arguments": { "node-name": "mydev",
1616 "write-threshold": 17179869184 } }
1624 - "name": switch name
1628 -> { "execute": "query-rocker", "arguments": { "name": "sw1" } }
1629 <- { "return": {"name": "sw1", "ports": 2, "id": 1327446905938}}
1631 Show rocker switch ports
1632 ------------------------
1636 - "name": switch name
1640 -> { "execute": "query-rocker-ports", "arguments": { "name": "sw1" } }
1641 <- { "return": [ {"duplex": "full", "enabled": true, "name": "sw1.1",
1642 "autoneg": "off", "link-up": true, "speed": 10000},
1643 {"duplex": "full", "enabled": true, "name": "sw1.2",
1644 "autoneg": "off", "link-up": true, "speed": 10000}
1647 Show rocker switch OF-DPA flow tables
1648 -------------------------------------
1652 - "name": switch name
1653 - "tbl-id": (optional) flow table ID
1657 -> { "execute": "query-rocker-of-dpa-flows", "arguments": { "name": "sw1" } }
1658 <- { "return": [ {"key": {"in-pport": 0, "priority": 1, "tbl-id": 0},
1661 "action": {"goto-tbl": 10},
1662 "mask": {"in-pport": 4294901760}
1667 Show rocker OF-DPA group tables
1668 -------------------------------
1672 - "name": switch name
1673 - "type": (optional) group type
1677 -> { "execute": "query-rocker-of-dpa-groups", "arguments": { "name": "sw1" } }
1678 <- { "return": [ {"type": 0, "out-pport": 2, "pport": 2, "vlan-id": 3841,
1679 "pop-vlan": 1, "id": 251723778},
1680 {"type": 0, "out-pport": 0, "pport": 0, "vlan-id": 3841,
1681 "pop-vlan": 1, "id": 251723776},
1682 {"type": 0, "out-pport": 1, "pport": 1, "vlan-id": 3840,
1683 "pop-vlan": 1, "id": 251658241},
1684 {"type": 0, "out-pport": 0, "pport": 0, "vlan-id": 3840,
1685 "pop-vlan": 1, "id": 251658240}
1688 query-gic-capabilities
1691 Return a list of GICCapability objects, describing supported GIC
1692 (Generic Interrupt Controller) versions.
1698 -> { "execute": "query-gic-capabilities" }
1699 <- { "return": [{ "version": 2, "emulated": true, "kernel": false },
1700 { "version": 3, "emulated": false, "kernel": true } ] }
1702 Show existing/possible CPUs
1703 ---------------------------
1707 Example for pseries machine type started with
1708 -smp 2,cores=2,maxcpus=4 -cpu POWER8:
1710 -> { "execute": "query-hotpluggable-cpus" }
1712 { "props": { "core-id": 8 }, "type": "POWER8-spapr-cpu-core",
1714 { "props": { "core-id": 0 }, "type": "POWER8-spapr-cpu-core",
1715 "vcpus-count": 1, "qom-path": "/machine/unattached/device[0]"}
1718 Example for pc machine type started with
1720 -> { "execute": "query-hotpluggable-cpus" }
1723 "type": "qemu64-x86_64-cpu", "vcpus-count": 1,
1724 "props": {"core-id": 0, "socket-id": 1, "thread-id": 0}
1727 "qom-path": "/machine/unattached/device[0]",
1728 "type": "qemu64-x86_64-cpu", "vcpus-count": 1,
1729 "props": {"core-id": 0, "socket-id": 0, "thread-id": 0}