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Diffstat (limited to 'QMP')
| -rw-r--r-- | QMP/README | 51 | ||||
| -rw-r--r-- | QMP/qmp-events.txt | 26 | ||||
| -rwxr-xr-x | QMP/qmp-shell | 72 | ||||
| -rw-r--r-- | QMP/qmp-spec.txt | 192 | ||||
| -rw-r--r-- | QMP/qmp.py | 72 | ||||
| -rwxr-xr-x | QMP/vm-info | 32 |
6 files changed, 445 insertions, 0 deletions
diff --git a/QMP/README b/QMP/README new file mode 100644 index 000000000..50c31f20c --- /dev/null +++ b/QMP/README @@ -0,0 +1,51 @@ + QEMU Monitor Protocol + ===================== + +Introduction +------------- + +The QEMU Monitor Protocol (QMP) is a JSON[1] based protocol for QEMU. + +By using it applications can control QEMU in reliable and "parseable" way, +QMP also provides asynchronous events support. + +For more information, please, refer to the following files: + +o qmp-spec.txt QEMU Monitor Protocol current draft specification +o qmp-events.txt List of available asynchronous events + +There are also two simple Python scripts available: + +o qmp-shell A shell +o vm-info Show some informations about the Virtal Machine + +[1] http://www.json.org + +Usage +----- + +To enable QMP, QEMU has to be started in "control mode". This is done +by passing the flag "control" to the "-monitor" command-line option. + +For example: + +$ qemu [...] -monitor control,tcp:localhost:4444,server + +Will start QEMU in control mode, waiting for a client TCP connection +on localhost port 4444. + +To manually test it you can connect with telnet and issue commands: + +$ telnet localhost 4444 +Trying ::1... +Connected to localhost. +Escape character is '^]'. +{"QMP": {"capabilities": []}} +{ "execute": "query-version" } +{"return": "0.11.50"} + +Contact +------- + +http://www.linux-kvm.org/page/MonitorProtocol +Luiz Fernando N. Capitulino <lcapitulino@redhat.com> diff --git a/QMP/qmp-events.txt b/QMP/qmp-events.txt new file mode 100644 index 000000000..682a5e53a --- /dev/null +++ b/QMP/qmp-events.txt @@ -0,0 +1,26 @@ + QEMU Monitor Protocol: Events + ============================= + +1 SHUTDOWN +----------- + +Description: Issued when the Virtual Machine is powered down. +Data: None. + +2 RESET +------- + +Description: Issued when the Virtual Machine is reseted. +Data: None. + +3 STOP +------ + +Description: Issued when the Virtual Machine is stopped. +Data: None. + +4 DEBUG +------- + +Description: Issued when the Virtual Machine enters debug mode. +Data: None. diff --git a/QMP/qmp-shell b/QMP/qmp-shell new file mode 100755 index 000000000..f89b9af87 --- /dev/null +++ b/QMP/qmp-shell @@ -0,0 +1,72 @@ +#!/usr/bin/python +# +# Simple QEMU shell on top of QMP +# +# Copyright (C) 2009 Red Hat Inc. +# +# Authors: +# Luiz Capitulino <lcapitulino@redhat.com> +# +# This work is licensed under the terms of the GNU GPL, version 2. See +# the COPYING file in the top-level directory. +# +# Usage: +# +# Start QEMU with: +# +# $ qemu [...] -monitor control,unix:./qmp,server +# +# Run the shell: +# +# $ qmp-shell ./qmp +# +# Commands have the following format: +# +# < command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ] +# +# For example: +# +# (QEMU) info item=network + +import qmp +import readline +from sys import argv,exit + +def shell_help(): + print 'bye exit from the shell' + +def main(): + if len(argv) != 2: + print 'qemu-shell <unix-socket>' + exit(1) + + qemu = qmp.QEMUMonitorProtocol(argv[1]) + qemu.connect() + + print 'Connected!' + + while True: + try: + cmd = raw_input('(QEMU) ') + except EOFError: + print + break + if cmd == '': + continue + elif cmd == 'bye': + break + elif cmd == 'help': + shell_help() + else: + try: + resp = qemu.send(cmd) + if resp == None: + print 'Disconnected' + break + print resp + except IndexError: + print '-> command format: <command-name> ', + print '[arg-name1=arg1] ... [arg-nameN=argN]' + +if __name__ == '__main__': + main() diff --git a/QMP/qmp-spec.txt b/QMP/qmp-spec.txt new file mode 100644 index 000000000..8429789a9 --- /dev/null +++ b/QMP/qmp-spec.txt @@ -0,0 +1,192 @@ + QEMU Monitor Protocol Draft Specification - Version 0.1 + +1. Introduction +=============== + +This document specifies the QEMU Monitor Protocol (QMP), a JSON-based protocol +which is available for applications to control QEMU at the machine-level. + +To enable QMP support, QEMU has to be run in "control mode". This is done by +starting QEMU with the appropriate command-line options. Please, refer to the +QEMU manual page for more information. + +2. Protocol Specification +========================= + +This section details the protocol format. For the purpose of this document +"Client" is any application which is communicating with QEMU in control mode, +and "Server" is QEMU itself. + +JSON data structures, when mentioned in this document, are always in the +following format: + + json-DATA-STRUCTURE-NAME + +Where DATA-STRUCTURE-NAME is any valid JSON data structure, as defined by +the JSON standard: + +http://www.ietf.org/rfc/rfc4627.txt + +For convenience, json-objects mentioned in this document will have its members +in a certain order. However, in real protocol usage json-objects members can +be in ANY order, thus no particular order should be assumed. + +2.1 General Definitions +----------------------- + +2.1.1 All interactions transmitted by the Server are json-objects, always + terminating with CRLF + +2.1.2 All json-objects members are mandatory when not specified otherwise + +2.2 Server Greeting +------------------- + +Right when connected the Server will issue a greeting message, which signals +that the connection has been successfully established and that the Server is +waiting for commands. + +The format is: + +{ "QMP": { "capabilities": json-array } } + + Where, + +- The "capabilities" member specify the availability of features beyond the + baseline specification + +2.3 Issuing Commands +-------------------- + +The format for command execution is: + +{ "execute": json-string, "arguments": json-object, "id": json-value } + + Where, + +- The "execute" member identifies the command to be executed by the Server +- The "arguments" member is used to pass any arguments required for the + execution of the command, it is optional when no arguments are required +- The "id" member is a transaction identification associated with the + command execution, it is optional and will be part of the response if + provided + +2.4 Commands Responses +---------------------- + +There are two possible responses which the Server will issue as the result +of a command execution: success or error. + +2.4.1 success +------------- + +The success response is issued when the command execution has finished +without errors. + +The format is: + +{ "return": json-value, "id": json-value } + + Where, + +- The "return" member contains the command returned data, which is defined + in a per-command basis or "OK" if the command does not return data +- The "id" member contains the transaction identification associated + with the command execution (if issued by the Client) + +2.4.2 error +----------- + +The error response is issued when the command execution could not be +completed because of an error condition. + +The format is: + +{ "error": { "class": json-string, "data": json-value }, "id": json-value } + + Where, + +- The "class" member contains the error class name (eg. "ServiceUnavailable") +- The "data" member contains specific error data and is defined in a + per-command basis, it will be an empty json-object if the error has no data +- The "id" member contains the transaction identification associated with + the command execution (if issued by the Client) + +NOTE: Some errors can occur before the Server is able to read the "id" member, +in these cases the "id" member will not be part of the error response, even +if provided by the client. + +2.5 Asynchronous events +----------------------- + +As a result of state changes, the Server may send messages unilaterally +to the Client at any time. They are called 'asynchronous events'. + +The format is: + +{ "event": json-string, "data": json-value, + "timestamp": { "seconds": json-number, "microseconds": json-number } } + + Where, + +- The "event" member contains the event's name +- The "data" member contains event specific data, which is defined in a + per-event basis, it is optional +- The "timestamp" member contains the exact time of when the event ocurred + in the Server. It is a fixed json-object with time in seconds and + microseconds + +For a listing of supported asynchronous events, please, refer to the +qmp-events.txt file. + +3. QMP Examples +=============== + +This section provides some examples of real QMP usage, in all of them +'C' stands for 'Client' and 'S' stands for 'Server'. + +3.1 Server greeting +------------------- + +S: {"QMP": {"capabilities": []}} + +3.2 Simple 'stop' execution +--------------------------- + +C: { "execute": "stop" } +S: {"return": "OK"} + +3.3 KVM information +------------------- + +C: {"execute": "query-kvm", "id": "example"} +S: {"return": "enabled", "id": "example"} + +3.4 Parsing error +------------------ + +C: { "execute": } +S: {"error": {"class": "JSONParsing", "data": {}}} + +3.5 Powerdown event +------------------- + +S: {"timestamp": {"seconds": 1258551470, "microseconds": 802384}, "event": +"POWERDOWN"} + +4. Notes to Client implementors +------------------------------- + +4.1 It is recommended to always start the Server in pause mode, thus the + Client is able to perform any setup procedure without the risk of + race conditions and related problems + +4.2 It is recommended to always check the capabilities json-array, issued + with the greeting message, at connection time + +4.3 Json-objects or json-arrays mentioned in this document are not fixed + and no particular size or number of members/elements should be assumed. + New members/elements can be added at any time. + +4.4 No particular order of json-objects members should be assumed, they + can change at any time diff --git a/QMP/qmp.py b/QMP/qmp.py new file mode 100644 index 000000000..d9da603be --- /dev/null +++ b/QMP/qmp.py @@ -0,0 +1,72 @@ +# QEMU Monitor Protocol Python class +# +# Copyright (C) 2009 Red Hat Inc. +# +# Authors: +# Luiz Capitulino <lcapitulino@redhat.com> +# +# This work is licensed under the terms of the GNU GPL, version 2. See +# the COPYING file in the top-level directory. + +import socket, json + +class QMPError(Exception): + pass + +class QMPConnectError(QMPError): + pass + +class QEMUMonitorProtocol: + def connect(self): + self.sock.connect(self.filename) + data = self.__json_read() + if data == None: + raise QMPConnectError + if not data.has_key('QMP'): + raise QMPConnectError + return data['QMP']['capabilities'] + + def close(self): + self.sock.close() + + def send_raw(self, line): + self.sock.send(str(line)) + return self.__json_read() + + def send(self, cmdline): + cmd = self.__build_cmd(cmdline) + self.__json_send(cmd) + resp = self.__json_read() + if resp == None: + return + elif resp.has_key('error'): + return resp['error'] + else: + return resp['return'] + + def __build_cmd(self, cmdline): + cmdargs = cmdline.split() + qmpcmd = { 'execute': cmdargs[0], 'arguments': {} } + for arg in cmdargs[1:]: + opt = arg.split('=') + try: + value = int(opt[1]) + except ValueError: + value = opt[1] + qmpcmd['arguments'][opt[0]] = value + return qmpcmd + + def __json_send(self, cmd): + # XXX: We have to send any additional char, otherwise + # the Server won't read our input + self.sock.send(json.dumps(cmd) + ' ') + + def __json_read(self): + try: + return json.loads(self.sock.recv(1024)) + except ValueError: + return + + def __init__(self, filename): + self.filename = filename + self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) diff --git a/QMP/vm-info b/QMP/vm-info new file mode 100755 index 000000000..b150d8240 --- /dev/null +++ b/QMP/vm-info @@ -0,0 +1,32 @@ +#!/usr/bin/python +# +# Print Virtual Machine information +# +# Usage: +# +# Start QEMU with: +# +# $ qemu [...] -monitor control,unix:./qmp,server +# +# Run vm-info: +# +# $ vm-info ./qmp +# +# Luiz Capitulino <lcapitulino@redhat.com> + +import qmp +from sys import argv,exit + +def main(): + if len(argv) != 2: + print 'vm-info <unix-socket>' + exit(1) + + qemu = qmp.QEMUMonitorProtocol(argv[1]) + qemu.connect() + + for cmd in [ 'version', 'hpet', 'kvm', 'status', 'uuid', 'balloon' ]: + print cmd + ': ' + str(qemu.send('query-' + cmd)) + +if __name__ == '__main__': + main() |