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authorRobert Mustacchi <rm@joyent.com>2011-06-24 13:49:54 -0700
committerRobert Mustacchi <rm@joyent.com>2011-06-24 13:49:54 -0700
commit68396ea9c0fe4f75ce30b1eba2c44c43c13344bb (patch)
tree802587d411d9db461e6500c5b635043315f81c27 /QMP
downloadillumos-kvm-cmd-68396ea9c0fe4f75ce30b1eba2c44c43c13344bb.tar.gz
Initial commit of d32e8d0b8d9e0ef7cf7ab2e74548982972789dfc from qemu-kvm
Diffstat (limited to 'QMP')
-rw-r--r--QMP/README88
-rw-r--r--QMP/qmp-events.txt266
-rwxr-xr-xQMP/qmp-shell259
-rw-r--r--QMP/qmp-spec.txt272
-rw-r--r--QMP/qmp.py131
5 files changed, 1016 insertions, 0 deletions
diff --git a/QMP/README b/QMP/README
new file mode 100644
index 0000000..c95a08c
--- /dev/null
+++ b/QMP/README
@@ -0,0 +1,88 @@
+ QEMU Monitor Protocol
+ =====================
+
+Introduction
+-------------
+
+The QEMU Monitor Protocol (QMP) allows applications to communicate with
+QEMU's Monitor.
+
+QMP is JSON[1] based and currently has the following features:
+
+- Lightweight, text-based, easy to parse data format
+- Asynchronous messages support (ie. events)
+- Capabilities Negotiation
+
+For detailed information on QMP's usage, please, refer to the following files:
+
+o qmp-spec.txt QEMU Monitor Protocol current specification
+o qmp-commands.txt QMP supported commands (auto-generated at build-time)
+o qmp-events.txt List of available asynchronous events
+
+There is also a simple Python script called 'qmp-shell' available.
+
+IMPORTANT: It's strongly recommended to read the 'Stability Considerations'
+section in the qmp-commands.txt file before making any serious use of QMP.
+
+
+[1] http://www.json.org
+
+Usage
+-----
+
+To enable QMP, you need a QEMU monitor instance in "control mode". There are
+two ways of doing this.
+
+The simplest one is using the '-qmp' command-line option. The following
+example makes QMP available on localhost port 4444:
+
+ $ qemu [...] -qmp tcp:localhost:4444,server
+
+However, in order to have more complex combinations, like multiple monitors,
+the '-mon' command-line option should be used along with the '-chardev' one.
+For instance, the following example creates one user monitor on stdio and one
+QMP monitor on localhost port 4444.
+
+ $ qemu [...] -chardev stdio,id=mon0 -mon chardev=mon0,mode=readline \
+ -chardev socket,id=mon1,host=localhost,port=4444,server \
+ -mon chardev=mon1,mode=control
+
+Please, refer to QEMU's manpage for more information.
+
+Simple Testing
+--------------
+
+To manually test QMP one can connect with telnet and issue commands by hand:
+
+$ telnet localhost 4444
+Trying 127.0.0.1...
+Connected to localhost.
+Escape character is '^]'.
+{"QMP": {"version": {"qemu": {"micro": 50, "minor": 13, "major": 0}, "package": ""}, "capabilities": []}}
+{ "execute": "qmp_capabilities" }
+{"return": {}}
+{ "execute": "query-version" }
+{"return": {"qemu": {"micro": 50, "minor": 13, "major": 0}, "package": ""}}
+
+Development Process
+-------------------
+
+When changing QMP's interface (by adding new commands, events or modifying
+existing ones) it's mandatory to update the relevant documentation, which is
+one (or more) of the files listed in the 'Introduction' section*.
+
+Also, it's strongly recommended to send the documentation patch first, before
+doing any code change. This is so because:
+
+ 1. Avoids the code dictating the interface
+
+ 2. Review can improve your interface. Letting that happen before
+ you implement it can save you work.
+
+* The qmp-commands.txt file is generated from the qmp-commands.hx one, which
+ is the file that should be edited.
+
+Homepage
+--------
+
+http://wiki.qemu.org/QMP
diff --git a/QMP/qmp-events.txt b/QMP/qmp-events.txt
new file mode 100644
index 0000000..0ce5d4e
--- /dev/null
+++ b/QMP/qmp-events.txt
@@ -0,0 +1,266 @@
+ QEMU Monitor Protocol Events
+ ============================
+
+BLOCK_IO_ERROR
+--------------
+
+Emitted when a disk I/O error occurs.
+
+Data:
+
+- "device": device name (json-string)
+- "operation": I/O operation (json-string, "read" or "write")
+- "action": action that has been taken, it's one of the following (json-string):
+ "ignore": error has been ignored
+ "report": error has been reported to the device
+ "stop": error caused VM to be stopped
+
+Example:
+
+{ "event": "BLOCK_IO_ERROR",
+ "data": { "device": "ide0-hd1",
+ "operation": "write",
+ "action": "stop" },
+ "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
+
+Note: If action is "stop", a STOP event will eventually follow the
+BLOCK_IO_ERROR event.
+
+RESET
+-----
+
+Emitted when the Virtual Machine is reseted.
+
+Data: None.
+
+Example:
+
+{ "event": "RESET",
+ "timestamp": { "seconds": 1267041653, "microseconds": 9518 } }
+
+RESUME
+------
+
+Emitted when the Virtual Machine resumes execution.
+
+Data: None.
+
+Example:
+
+{ "event": "RESUME",
+ "timestamp": { "seconds": 1271770767, "microseconds": 582542 } }
+
+RTC_CHANGE
+----------
+
+Emitted when the guest changes the RTC time.
+
+Data:
+
+- "offset": delta against the host UTC in seconds (json-number)
+
+Example:
+
+{ "event": "RTC_CHANGE",
+ "data": { "offset": 78 },
+ "timestamp": { "seconds": 1267020223, "microseconds": 435656 } }
+
+SHUTDOWN
+--------
+
+Emitted when the Virtual Machine is powered down.
+
+Data: None.
+
+Example:
+
+{ "event": "SHUTDOWN",
+ "timestamp": { "seconds": 1267040730, "microseconds": 682951 } }
+
+Note: If the command-line option "-no-shutdown" has been specified, a STOP
+event will eventually follow the SHUTDOWN event.
+
+STOP
+----
+
+Emitted when the Virtual Machine is stopped.
+
+Data: None.
+
+Example:
+
+{ "event": "STOP",
+ "timestamp": { "seconds": 1267041730, "microseconds": 281295 } }
+
+VNC_CONNECTED
+-------------
+
+Emitted when a VNC client establishes a connection.
+
+Data:
+
+- "server": Server information (json-object)
+ - "host": IP address (json-string)
+ - "service": port number (json-string)
+ - "family": address family (json-string, "ipv4" or "ipv6")
+ - "auth": authentication method (json-string, optional)
+- "client": Client information (json-object)
+ - "host": IP address (json-string)
+ - "service": port number (json-string)
+ - "family": address family (json-string, "ipv4" or "ipv6")
+
+Example:
+
+{ "event": "VNC_CONNECTED",
+ "data": {
+ "server": { "auth": "sasl", "family": "ipv4",
+ "service": "5901", "host": "0.0.0.0" },
+ "client": { "family": "ipv4", "service": "58425",
+ "host": "127.0.0.1" } },
+ "timestamp": { "seconds": 1262976601, "microseconds": 975795 } }
+
+
+Note: This event is emitted before any authentication takes place, thus
+the authentication ID is not provided.
+
+VNC_DISCONNECTED
+----------------
+
+Emitted when the conection is closed.
+
+Data:
+
+- "server": Server information (json-object)
+ - "host": IP address (json-string)
+ - "service": port number (json-string)
+ - "family": address family (json-string, "ipv4" or "ipv6")
+ - "auth": authentication method (json-string, optional)
+- "client": Client information (json-object)
+ - "host": IP address (json-string)
+ - "service": port number (json-string)
+ - "family": address family (json-string, "ipv4" or "ipv6")
+ - "x509_dname": TLS dname (json-string, optional)
+ - "sasl_username": SASL username (json-string, optional)
+
+Example:
+
+{ "event": "VNC_DISCONNECTED",
+ "data": {
+ "server": { "auth": "sasl", "family": "ipv4",
+ "service": "5901", "host": "0.0.0.0" },
+ "client": { "family": "ipv4", "service": "58425",
+ "host": "127.0.0.1", "sasl_username": "luiz" } },
+ "timestamp": { "seconds": 1262976601, "microseconds": 975795 } }
+
+VNC_INITIALIZED
+---------------
+
+Emitted after authentication takes place (if any) and the VNC session is
+made active.
+
+Data:
+
+- "server": Server information (json-object)
+ - "host": IP address (json-string)
+ - "service": port number (json-string)
+ - "family": address family (json-string, "ipv4" or "ipv6")
+ - "auth": authentication method (json-string, optional)
+- "client": Client information (json-object)
+ - "host": IP address (json-string)
+ - "service": port number (json-string)
+ - "family": address family (json-string, "ipv4" or "ipv6")
+ - "x509_dname": TLS dname (json-string, optional)
+ - "sasl_username": SASL username (json-string, optional)
+
+Example:
+
+{ "event": "VNC_INITIALIZED",
+ "data": {
+ "server": { "auth": "sasl", "family": "ipv4",
+ "service": "5901", "host": "0.0.0.0"},
+ "client": { "family": "ipv4", "service": "46089",
+ "host": "127.0.0.1", "sasl_username": "luiz" } },
+ "timestamp": { "seconds": 1263475302, "microseconds": 150772 } }
+
+SPICE_CONNECTED, SPICE_DISCONNECTED
+-----------------------------------
+
+Emitted when a SPICE client connects or disconnects.
+
+Data:
+
+- "server": Server information (json-object)
+ - "host": IP address (json-string)
+ - "port": port number (json-string)
+ - "family": address family (json-string, "ipv4" or "ipv6")
+- "client": Client information (json-object)
+ - "host": IP address (json-string)
+ - "port": port number (json-string)
+ - "family": address family (json-string, "ipv4" or "ipv6")
+
+Example:
+
+{ "timestamp": {"seconds": 1290688046, "microseconds": 388707},
+ "event": "SPICE_CONNECTED",
+ "data": {
+ "server": { "port": "5920", "family": "ipv4", "host": "127.0.0.1"},
+ "client": {"port": "52873", "family": "ipv4", "host": "127.0.0.1"}
+}}
+
+
+SPICE_INITIALIZED
+-----------------
+
+Emitted after initial handshake and authentication takes place (if any)
+and the SPICE channel is up'n'running
+
+Data:
+
+- "server": Server information (json-object)
+ - "host": IP address (json-string)
+ - "port": port number (json-string)
+ - "family": address family (json-string, "ipv4" or "ipv6")
+ - "auth": authentication method (json-string, optional)
+- "client": Client information (json-object)
+ - "host": IP address (json-string)
+ - "port": port number (json-string)
+ - "family": address family (json-string, "ipv4" or "ipv6")
+ - "connection-id": spice connection id. All channels with the same id
+ belong to the same spice session (json-int)
+ - "channel-type": channel type. "1" is the main control channel, filter for
+ this one if you want track spice sessions only (json-int)
+ - "channel-id": channel id. Usually "0", might be different needed when
+ multiple channels of the same type exist, such as multiple
+ display channels in a multihead setup (json-int)
+ - "tls": whevener the channel is encrypted (json-bool)
+
+Example:
+
+{ "timestamp": {"seconds": 1290688046, "microseconds": 417172},
+ "event": "SPICE_INITIALIZED",
+ "data": {"server": {"auth": "spice", "port": "5921",
+ "family": "ipv4", "host": "127.0.0.1"},
+ "client": {"port": "49004", "family": "ipv4", "channel-type": 3,
+ "connection-id": 1804289383, "host": "127.0.0.1",
+ "channel-id": 0, "tls": true}
+}}
+
+
+WATCHDOG
+--------
+
+Emitted when the watchdog device's timer is expired.
+
+Data:
+
+- "action": Action that has been taken, it's one of the following (json-string):
+ "reset", "shutdown", "poweroff", "pause", "debug", or "none"
+
+Example:
+
+{ "event": "WATCHDOG",
+ "data": { "action": "reset" },
+ "timestamp": { "seconds": 1267061043, "microseconds": 959568 } }
+
+Note: If action is "reset", "shutdown", or "pause" the WATCHDOG event is
+followed respectively by the RESET, SHUTDOWN, or STOP events.
diff --git a/QMP/qmp-shell b/QMP/qmp-shell
new file mode 100755
index 0000000..42dabc8
--- /dev/null
+++ b/QMP/qmp-shell
@@ -0,0 +1,259 @@
+#!/usr/bin/python
+#
+# Low-level QEMU shell on top of QMP.
+#
+# Copyright (C) 2009, 2010 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 [...] -qmp unix:./qmp-sock,server
+#
+# Run the shell:
+#
+# $ qmp-shell ./qmp-sock
+#
+# Commands have the following format:
+#
+# < command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ]
+#
+# For example:
+#
+# (QEMU) device_add driver=e1000 id=net1
+# {u'return': {}}
+# (QEMU)
+
+import qmp
+import readline
+import sys
+
+class QMPCompleter(list):
+ def complete(self, text, state):
+ for cmd in self:
+ if cmd.startswith(text):
+ if not state:
+ return cmd
+ else:
+ state -= 1
+
+class QMPShellError(Exception):
+ pass
+
+class QMPShellBadPort(QMPShellError):
+ pass
+
+# TODO: QMPShell's interface is a bit ugly (eg. _fill_completion() and
+# _execute_cmd()). Let's design a better one.
+class QMPShell(qmp.QEMUMonitorProtocol):
+ def __init__(self, address):
+ qmp.QEMUMonitorProtocol.__init__(self, self.__get_address(address))
+ self._greeting = None
+ self._completer = None
+
+ def __get_address(self, arg):
+ """
+ Figure out if the argument is in the port:host form, if it's not it's
+ probably a file path.
+ """
+ addr = arg.split(':')
+ if len(addr) == 2:
+ try:
+ port = int(addr[1])
+ except ValueError:
+ raise QMPShellBadPort
+ return ( addr[0], port )
+ # socket path
+ return arg
+
+ def _fill_completion(self):
+ for cmd in self.cmd('query-commands')['return']:
+ self._completer.append(cmd['name'])
+
+ def __completer_setup(self):
+ self._completer = QMPCompleter()
+ self._fill_completion()
+ readline.set_completer(self._completer.complete)
+ readline.parse_and_bind("tab: complete")
+ # XXX: default delimiters conflict with some command names (eg. query-),
+ # clearing everything as it doesn't seem to matter
+ readline.set_completer_delims('')
+
+ def __build_cmd(self, cmdline):
+ """
+ Build a QMP input object from a user provided command-line in the
+ following format:
+
+ < command-name > [ arg-name1=arg1 ] ... [ arg-nameN=argN ]
+ """
+ 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 _execute_cmd(self, cmdline):
+ try:
+ qmpcmd = self.__build_cmd(cmdline)
+ except:
+ print 'command format: <command-name> ',
+ print '[arg-name1=arg1] ... [arg-nameN=argN]'
+ return True
+ resp = self.cmd_obj(qmpcmd)
+ if resp is None:
+ print 'Disconnected'
+ return False
+ print resp
+ return True
+
+ def connect(self):
+ self._greeting = qmp.QEMUMonitorProtocol.connect(self)
+ self.__completer_setup()
+
+ def show_banner(self, msg='Welcome to the QMP low-level shell!'):
+ print msg
+ version = self._greeting['QMP']['version']['qemu']
+ print 'Connected to QEMU %d.%d.%d\n' % (version['major'],version['minor'],version['micro'])
+
+ def read_exec_command(self, prompt):
+ """
+ Read and execute a command.
+
+ @return True if execution was ok, return False if disconnected.
+ """
+ try:
+ cmdline = raw_input(prompt)
+ except EOFError:
+ print
+ return False
+ if cmdline == '':
+ for ev in self.get_events():
+ print ev
+ self.clear_events()
+ return True
+ else:
+ return self._execute_cmd(cmdline)
+
+class HMPShell(QMPShell):
+ def __init__(self, address):
+ QMPShell.__init__(self, address)
+ self.__cpu_index = 0
+
+ def __cmd_completion(self):
+ for cmd in self.__cmd_passthrough('help')['return'].split('\r\n'):
+ if cmd and cmd[0] != '[' and cmd[0] != '\t':
+ name = cmd.split()[0] # drop help text
+ if name == 'info':
+ continue
+ if name.find('|') != -1:
+ # Command in the form 'foobar|f' or 'f|foobar', take the
+ # full name
+ opt = name.split('|')
+ if len(opt[0]) == 1:
+ name = opt[1]
+ else:
+ name = opt[0]
+ self._completer.append(name)
+ self._completer.append('help ' + name) # help completion
+
+ def __info_completion(self):
+ for cmd in self.__cmd_passthrough('info')['return'].split('\r\n'):
+ if cmd:
+ self._completer.append('info ' + cmd.split()[1])
+
+ def __other_completion(self):
+ # special cases
+ self._completer.append('help info')
+
+ def _fill_completion(self):
+ self.__cmd_completion()
+ self.__info_completion()
+ self.__other_completion()
+
+ def __cmd_passthrough(self, cmdline, cpu_index = 0):
+ return self.cmd_obj({ 'execute': 'human-monitor-command', 'arguments':
+ { 'command-line': cmdline,
+ 'cpu-index': cpu_index } })
+
+ def _execute_cmd(self, cmdline):
+ if cmdline.split()[0] == "cpu":
+ # trap the cpu command, it requires special setting
+ try:
+ idx = int(cmdline.split()[1])
+ if not 'return' in self.__cmd_passthrough('info version', idx):
+ print 'bad CPU index'
+ return True
+ self.__cpu_index = idx
+ except ValueError:
+ print 'cpu command takes an integer argument'
+ return True
+ resp = self.__cmd_passthrough(cmdline, self.__cpu_index)
+ if resp is None:
+ print 'Disconnected'
+ return False
+ assert 'return' in resp or 'error' in resp
+ if 'return' in resp:
+ # Success
+ if len(resp['return']) > 0:
+ print resp['return'],
+ else:
+ # Error
+ print '%s: %s' % (resp['error']['class'], resp['error']['desc'])
+ return True
+
+ def show_banner(self):
+ QMPShell.show_banner(self, msg='Welcome to the HMP shell!')
+
+def die(msg):
+ sys.stderr.write('ERROR: %s\n' % msg)
+ sys.exit(1)
+
+def fail_cmdline(option=None):
+ if option:
+ sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
+ sys.stderr.write('qemu-shell [ -H ] < UNIX socket path> | < TCP address:port >\n')
+ sys.exit(1)
+
+def main():
+ addr = ''
+ try:
+ if len(sys.argv) == 2:
+ qemu = QMPShell(sys.argv[1])
+ addr = sys.argv[1]
+ elif len(sys.argv) == 3:
+ if sys.argv[1] != '-H':
+ fail_cmdline(sys.argv[1])
+ qemu = HMPShell(sys.argv[2])
+ addr = sys.argv[2]
+ else:
+ fail_cmdline()
+ except QMPShellBadPort:
+ die('bad port number in command-line')
+
+ try:
+ qemu.connect()
+ except qmp.QMPConnectError:
+ die('Didn\'t get QMP greeting message')
+ except qmp.QMPCapabilitiesError:
+ die('Could not negotiate capabilities')
+ except qemu.error:
+ die('Could not connect to %s' % addr)
+
+ qemu.show_banner()
+ while qemu.read_exec_command('(QEMU) '):
+ pass
+ qemu.close()
+
+if __name__ == '__main__':
+ main()
diff --git a/QMP/qmp-spec.txt b/QMP/qmp-spec.txt
new file mode 100644
index 0000000..9d30a8c
--- /dev/null
+++ b/QMP/qmp-spec.txt
@@ -0,0 +1,272 @@
+ QEMU Monitor Protocol 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-object members and json-array elements mentioned in
+this document will be in a certain order. However, in real protocol usage
+they 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
+ready for capabilities negotiation (for more information refer to section
+'4. Capabilities Negotiation').
+
+The format is:
+
+{ "QMP": { "version": json-object, "capabilities": json-array } }
+
+ Where,
+
+- The "version" member contains the Server's version information (the format
+ is the same of the 'query-version' command)
+- 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-object, "id": json-value }
+
+ Where,
+
+- The "return" member contains the command returned data, which is defined
+ in a per-command basis or an empty json-object 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-object, "desc": json-string },
+ "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 "desc" member is a human-readable error message. Clients should
+ not attempt to parse this message.
+- 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-object,
+ "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 occurred
+ 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": {"version": {"qemu": "0.12.50", "package": ""}, "capabilities": []}}
+
+3.2 Simple 'stop' execution
+---------------------------
+
+C: { "execute": "stop" }
+S: {"return": {}}
+
+3.3 KVM information
+-------------------
+
+C: { "execute": "query-kvm", "id": "example" }
+S: {"return": {"enabled": true, "present": true}, "id": "example"}
+
+3.4 Parsing error
+------------------
+
+C: { "execute": }
+S: {"error": {"class": "JSONParsing", "desc": "Invalid JSON syntax", "data":
+{}}}
+
+3.5 Powerdown event
+-------------------
+
+S: {"timestamp": {"seconds": 1258551470, "microseconds": 802384}, "event":
+"POWERDOWN"}
+
+4. Capabilities Negotiation
+----------------------------
+
+When a Client successfully establishes a connection, the Server is in
+Capabilities Negotiation mode.
+
+In this mode only the 'qmp_capabilities' command is allowed to run, all
+other commands will return the CommandNotFound error. Asynchronous messages
+are not delivered either.
+
+Clients should use the 'qmp_capabilities' command to enable capabilities
+advertised in the Server's greeting (section '2.2 Server Greeting') they
+support.
+
+When the 'qmp_capabilities' command is issued, and if it does not return an
+error, the Server enters in Command mode where capabilities changes take
+effect, all commands (except 'qmp_capabilities') are allowed and asynchronous
+messages are delivered.
+
+5 Compatibility Considerations
+------------------------------
+
+All protocol changes or new features which modify the protocol format in an
+incompatible way are disabled by default and will be advertised by the
+capabilities array (section '2.2 Server Greeting'). Thus, Clients can check
+that array and enable the capabilities they support.
+
+Additionally, Clients must not assume any particular:
+
+- Size of json-objects or length of json-arrays
+- Order of json-object members or json-array elements
+- Amount of errors generated by a command, that is, new errors can be added
+ to any existing command in newer versions of the Server
+
+6. Downstream extension of QMP
+------------------------------
+
+We recommend that downstream consumers of QEMU do *not* modify QMP.
+Management tools should be able to support both upstream and downstream
+versions of QMP without special logic, and downstream extensions are
+inherently at odds with that.
+
+However, we recognize that it is sometimes impossible for downstreams to
+avoid modifying QMP. Both upstream and downstream need to take care to
+preserve long-term compatibility and interoperability.
+
+To help with that, QMP reserves JSON object member names beginning with
+'__' (double underscore) for downstream use ("downstream names"). This
+means upstream will never use any downstream names for its commands,
+arguments, errors, asynchronous events, and so forth.
+
+Any new names downstream wishes to add must begin with '__'. To
+ensure compatibility with other downstreams, it is strongly
+recommended that you prefix your downstram names with '__RFQDN_' where
+RFQDN is a valid, reverse fully qualified domain name which you
+control. For example, a qemu-kvm specific monitor command would be:
+
+ (qemu) __org.linux-kvm_enable_irqchip
+
+Downstream must not change the server greeting (section 2.2) other than
+to offer additional capabilities. But see below for why even that is
+discouraged.
+
+Section '5 Compatibility Considerations' applies to downstream as well
+as to upstream, obviously. It follows that downstream must behave
+exactly like upstream for any input not containing members with
+downstream names ("downstream members"), except it may add members
+with downstream names to its output.
+
+Thus, a client should not be able to distinguish downstream from
+upstream as long as it doesn't send input with downstream members, and
+properly ignores any downstream members in the output it receives.
+
+Advice on downstream modifications:
+
+1. Introducing new commands is okay. If you want to extend an existing
+ command, consider introducing a new one with the new behaviour
+ instead.
+
+2. Introducing new asynchronous messages is okay. If you want to extend
+ an existing message, consider adding a new one instead.
+
+3. Introducing new errors for use in new commands is okay. Adding new
+ errors to existing commands counts as extension, so 1. applies.
+
+4. New capabilities are strongly discouraged. Capabilities are for
+ evolving the basic protocol, and multiple diverging basic protocol
+ dialects are most undesirable.
diff --git a/QMP/qmp.py b/QMP/qmp.py
new file mode 100644
index 0000000..14ce8b0
--- /dev/null
+++ b/QMP/qmp.py
@@ -0,0 +1,131 @@
+# QEMU Monitor Protocol Python class
+#
+# Copyright (C) 2009, 2010 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 json
+import errno
+import socket
+
+class QMPError(Exception):
+ pass
+
+class QMPConnectError(QMPError):
+ pass
+
+class QMPCapabilitiesError(QMPError):
+ pass
+
+class QEMUMonitorProtocol:
+ def __init__(self, address):
+ """
+ Create a QEMUMonitorProtocol class.
+
+ @param address: QEMU address, can be either a unix socket path (string)
+ or a tuple in the form ( address, port ) for a TCP
+ connection
+ @note No connection is established, this is done by the connect() method
+ """
+ self.__events = []
+ self.__address = address
+ self.__sock = self.__get_sock()
+ self.__sockfile = self.__sock.makefile()
+
+ def __get_sock(self):
+ if isinstance(self.__address, tuple):
+ family = socket.AF_INET
+ else:
+ family = socket.AF_UNIX
+ return socket.socket(family, socket.SOCK_STREAM)
+
+ def __json_read(self):
+ while True:
+ data = self.__sockfile.readline()
+ if not data:
+ return
+ resp = json.loads(data)
+ if 'event' in resp:
+ self.__events.append(resp)
+ continue
+ return resp
+
+ error = socket.error
+
+ def connect(self):
+ """
+ Connect to the QMP Monitor and perform capabilities negotiation.
+
+ @return QMP greeting dict
+ @raise socket.error on socket connection errors
+ @raise QMPConnectError if the greeting is not received
+ @raise QMPCapabilitiesError if fails to negotiate capabilities
+ """
+ self.__sock.connect(self.__address)
+ greeting = self.__json_read()
+ if greeting is None or not greeting.has_key('QMP'):
+ raise QMPConnectError
+ # Greeting seems ok, negotiate capabilities
+ resp = self.cmd('qmp_capabilities')
+ if "return" in resp:
+ return greeting
+ raise QMPCapabilitiesError
+
+ def cmd_obj(self, qmp_cmd):
+ """
+ Send a QMP command to the QMP Monitor.
+
+ @param qmp_cmd: QMP command to be sent as a Python dict
+ @return QMP response as a Python dict or None if the connection has
+ been closed
+ """
+ try:
+ self.__sock.sendall(json.dumps(qmp_cmd))
+ except socket.error, err:
+ if err[0] == errno.EPIPE:
+ return
+ raise socket.error(err)
+ return self.__json_read()
+
+ def cmd(self, name, args=None, id=None):
+ """
+ Build a QMP command and send it to the QMP Monitor.
+
+ @param name: command name (string)
+ @param args: command arguments (dict)
+ @param id: command id (dict, list, string or int)
+ """
+ qmp_cmd = { 'execute': name }
+ if args:
+ qmp_cmd['arguments'] = args
+ if id:
+ qmp_cmd['id'] = id
+ return self.cmd_obj(qmp_cmd)
+
+ def get_events(self):
+ """
+ Get a list of available QMP events.
+ """
+ self.__sock.setblocking(0)
+ try:
+ self.__json_read()
+ except socket.error, err:
+ if err[0] == errno.EAGAIN:
+ # No data available
+ pass
+ self.__sock.setblocking(1)
+ return self.__events
+
+ def clear_events(self):
+ """
+ Clear current list of pending events.
+ """
+ self.__events = []
+
+ def close(self):
+ self.__sock.close()
+ self.__sockfile.close()