MonitorProtocol
QEMU Monitor Protocol
The QEMU Monitor Protocol (QMP) allows applications to communicate with QEMU's Monitor.
QMP is JSON-based, its main features are:
- Lightweight, text-based, easy to parse data format
- Asynchronous events support
Its full specification can be found here and the README file explains how to use it.
General Status
QMP is available in QEMU since version 0.13.
However, it is still under development and not all Monitor commands are currently available.
A detailed status can be found in the bottom of this page.
Examples
In the following examples, 'C' stands for 'Client' and 'S' stands for 'Server'.
Server Greeting
S: {"QMP": {"capabilities": []}}
Query version
C: { "execute": "query-version" }
S: {"return": {"qemu": "0.11.50", "package": ""}}
Eject a device
C: { "execute": "eject", "arguments": { "device": "ide1-cd0" } }
S: {"return": "OK"}
Development
Primary contact is Luiz Capitulino, but most QMP-related discussions happen on the qemu-devel mailing list.
Next features, hot fixes and other patches are stored in the QMP unstable repository:
http://repo.or.cz/w/qemu/qmp-unstable.git
NOTE: all branches in this repository are constantly rebased.
TODO
- High-level documentation
- Convert all commands
- Proper error handling support
- Asynchronous commands
- Libqmp
Conversion status (2009-12-07)
| Command | Info | |
| Handlers | 61 | 35 |
| Fully Converted | 7 | 14 |
| Percentage | 11% | 40% |
The following tables have a per-function status. There is one table for command handlers and another one for info handlers.
Status can be:
- merged: already merged upstream
- converted: converted but not merged yet
- partial: not fully converted
- never fails: does not need error handling
NOTE: Handlers used by Libvirt are marked with yellow.
Command handlers
| Handler name | Output in QObject | Error handling | Comments |
| do_acl_add() | |||
| do_acl_policy() | |||
| do_acl_remove() | |||
| do_acl_reset() | |||
| do_acl_show() | |||
| do_balloon() | merged | never fails | |
| do_boot_set() | |||
| do_change() | |||
| do_closefd() | merged | ||
| do_commit() | |||
| do_cont() | merged | never fails | TODO: encrypted images |
| do_cpu_set() | |||
| do_delvm() | |||
| do_device_add() | |||
| do_device_del() | |||
| do_eject() | merged | ||
| do_gdbserver() | |||
| do_getfd() | merged | ||
| do_help_cmd() | |||
| do_info() | merged | ||
| do_inject_mce() | |||
| do_inject_nmi() | |||
| do_ioport_read() | |||
| do_ioport_write() | |||
| do_loadvm() | |||
| do_log() | |||
| do_logfile() | |||
| do_memory_dump() | |||
| do_memory_save() | merged | ||
| do_migrate() | merged | ||
| do_migrate_cancel() | merged | never fails | |
| do_migrate_set_downtime() | |||
| do_migrate_set_speed() | merged | never fails | |
| do_mouse_button() | |||
| do_mouse_move() | |||
| do_mouse_set() | |||
| do_pci_device_hot_remove() | merged | ||
| do_physical_memory_dump() | |||
| do_physical_memory_save() | merged | ||
| do_print() | |||
| do_quit() | merged | ||
| do_savevm() | |||
| do_screen_dump() | |||
| do_sendkey() | |||
| do_set_link() | |||
| do_singlestep() | |||
| do_stop() | merged | never fails | |
| do_stop_capture() | |||
| do_sum() | |||
| do_system_powerdown() | merged | nerver fails | |
| do_system_reset() | merged | never fails | |
| do_usb_add() | |||
| do_usb_del() | |||
| do_watchdog_action() | |||
| do_wav_capture() | |||
| drive_hot_add() | |||
| net_host_device_add() | |||
| net_host_device_remove() | |||
| net_slirp_hostfwd_add() | |||
| net_slirp_hostfwd_remove() | |||
| pci_device_hot_add() | converted |
Info handlers
| Handler name | Status | Comments |
| bdrv_info() | converted | |
| bdrv_info_stats() | converted | |
| do_info_balloon() | merged | |
| do_info_capture() | ||
| do_info_cpus() | merged | |
| do_info_cpu_stats() | ||
| do_info_history() | ||
| do_info_hpet() | converted | |
| do_info_jit() | ||
| do_info_kvm() | converted | |
| do_info_mice() | converted | |
| do_info_migrate() | converted | |
| do_info_name() | converted | |
| do_info_network() | partial | |
| do_info_numa() | ||
| do_info_profile() | ||
| do_info_qdm() | ||
| do_info_qtree() | ||
| do_info_registers() | ||
| do_info_roms() | ||
| do_info_snapshots() | ||
| do_info_status() | converted | |
| do_info_usernet() | partial | |
| do_info_uuid() | converted | |
| do_info_version() | merged | |
| do_info_vnc() | converted | |
| irq_info() | ||
| mem_info() | ||
| pci_info() | ||
| pcmcia_info() | ||
| pic_info() | ||
| qemu_chr_info() | converted | |
| tlb_info() | ||
| usb_host_info() | ||
| usb_info() |
History
This was the fourth proposal for a Monitor protocol, past discussions can be found in the following links: