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 (docs/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. 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 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. xen-load-devices-state ---------------------- Load the state of all devices from file. The RAM and the block devices of the VM are not loaded by this command. Arguments: - "filename": the file to load the state of the devices from as binary data. See xen-save-devices-state.txt for a description of the binary format. Example: -> { "execute": "xen-load-devices-state", "arguments": { "filename": "/tmp/resume" } } <- { "return": {} } x-colo-lost-heartbeat -------------------- Tell COLO that heartbeat is lost, a failover or takeover is needed. Example: -> { "execute": "x-colo-lost-heartbeat" } <- { "return": {} } qmp_capabilities ---------------- Enable QMP capabilities. Arguments: None. Example: -> { "execute": "qmp_capabilities" } <- { "return": {} } Note: This command must be issued before issuing any other command. 3. Query Commands ================= query-qmp-schema ---------------- Return the QMP wire schema. The returned value is a json-array of named schema entities. Entities are commands, events and various types. See docs/qapi-code-gen.txt for information on their structure and intended use.