aboutsummaryrefslogtreecommitdiff
path: root/scripts/qemu.py
blob: bde8da8fe7b5667386b06cea5b04d7af78955f94 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
# QEMU library
#
# Copyright (C) 2015-2016 Red Hat Inc.
# Copyright (C) 2012 IBM Corp.
#
# Authors:
#  Fam Zheng <famz@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2.  See
# the COPYING file in the top-level directory.
#
# Based on qmp.py.
#

import errno
import os
import sys
import subprocess
import qmp.qmp


class QEMUMachine(object):
    '''A QEMU VM

    Use this object as a context manager to ensure the QEMU process terminates::

        with VM(binary) as vm:
            ...
        # vm is guaranteed to be shut down here
    '''

    def __init__(self, binary, args=None, wrapper=None, name=None,
                 test_dir="/var/tmp", monitor_address=None,
                 socket_scm_helper=None, debug=False):
        '''
        Initialize a QEMUMachine

        @param binary: path to the qemu binary
        @param args: list of extra arguments
        @param wrapper: list of arguments used as prefix to qemu binary
        @param name: prefix for socket and log file names (default: qemu-PID)
        @param test_dir: where to create socket and log file
        @param monitor_address: address for QMP monitor
        @param socket_scm_helper: helper program, required for send_fd_scm()"
        @param debug: enable debug mode
        @note: Qemu process is not started until launch() is used.
        '''
        if args is None:
            args = []
        if wrapper is None:
            wrapper = []
        if name is None:
            name = "qemu-%d" % os.getpid()
        if monitor_address is None:
            monitor_address = os.path.join(test_dir, name + "-monitor.sock")
        self._monitor_address = monitor_address
        self._qemu_log_path = os.path.join(test_dir, name + ".log")
        self._popen = None
        self._binary = binary
        self._args = list(args)     # Force copy args in case we modify them
        self._wrapper = wrapper
        self._events = []
        self._iolog = None
        self._socket_scm_helper = socket_scm_helper
        self._debug = debug
        self._qmp = None

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.shutdown()
        return False

    # This can be used to add an unused monitor instance.
    def add_monitor_telnet(self, ip, port):
        args = 'tcp:%s:%d,server,nowait,telnet' % (ip, port)
        self._args.append('-monitor')
        self._args.append(args)

    def add_fd(self, fd, fdset, opaque, opts=''):
        '''Pass a file descriptor to the VM'''
        options = ['fd=%d' % fd,
                   'set=%d' % fdset,
                   'opaque=%s' % opaque]
        if opts:
            options.append(opts)

        self._args.append('-add-fd')
        self._args.append(','.join(options))
        return self

    def send_fd_scm(self, fd_file_path):
        # In iotest.py, the qmp should always use unix socket.
        assert self._qmp.is_scm_available()
        if self._socket_scm_helper is None:
            print >>sys.stderr, "No path to socket_scm_helper set"
            return -1
        if not os.path.exists(self._socket_scm_helper):
            print >>sys.stderr, "%s does not exist" % self._socket_scm_helper
            return -1
        fd_param = ["%s" % self._socket_scm_helper,
                    "%d" % self._qmp.get_sock_fd(),
                    "%s" % fd_file_path]
        devnull = open('/dev/null', 'rb')
        proc = subprocess.Popen(fd_param, stdin=devnull, stdout=sys.stdout,
                                stderr=sys.stderr)
        return proc.wait()

    @staticmethod
    def _remove_if_exists(path):
        '''Remove file object at path if it exists'''
        try:
            os.remove(path)
        except OSError as exception:
            if exception.errno == errno.ENOENT:
                return
            raise

    def is_running(self):
        return self._popen and (self._popen.returncode is None)

    def exitcode(self):
        if self._popen is None:
            return None
        return self._popen.returncode

    def get_pid(self):
        if not self.is_running():
            return None
        return self._popen.pid

    def _load_io_log(self):
        with open(self._qemu_log_path, "r") as iolog:
            self._iolog = iolog.read()

    def _base_args(self):
        if isinstance(self._monitor_address, tuple):
            moncdev = "socket,id=mon,host=%s,port=%s" % (
                self._monitor_address[0],
                self._monitor_address[1])
        else:
            moncdev = 'socket,id=mon,path=%s' % self._monitor_address
        return ['-chardev', moncdev,
                '-mon', 'chardev=mon,mode=control',
                '-display', 'none', '-vga', 'none']

    def _pre_launch(self):
        self._qmp = qmp.qmp.QEMUMonitorProtocol(self._monitor_address,
                                                server=True,
                                                debug=self._debug)

    def _post_launch(self):
        self._qmp.accept()

    def _post_shutdown(self):
        if not isinstance(self._monitor_address, tuple):
            self._remove_if_exists(self._monitor_address)
        self._remove_if_exists(self._qemu_log_path)

    def launch(self):
        '''Launch the VM and establish a QMP connection'''
        devnull = open('/dev/null', 'rb')
        qemulog = open(self._qemu_log_path, 'wb')
        try:
            self._pre_launch()
            args = (self._wrapper + [self._binary] + self._base_args() +
                    self._args)
            self._popen = subprocess.Popen(args, stdin=devnull, stdout=qemulog,
                                           stderr=subprocess.STDOUT,
                                           shell=False)
            self._post_launch()
        except:
            if self.is_running():
                self._popen.kill()
                self._popen.wait()
            self._load_io_log()
            self._post_shutdown()
            raise

    def shutdown(self):
        '''Terminate the VM and clean up'''
        if self.is_running():
            try:
                self._qmp.cmd('quit')
                self._qmp.close()
            except:
                self._popen.kill()

            exitcode = self._popen.wait()
            if exitcode < 0:
                sys.stderr.write('qemu received signal %i: %s\n'
                                 % (-exitcode, ' '.join(self._args)))
            self._load_io_log()
            self._post_shutdown()

    def qmp(self, cmd, conv_keys=True, **args):
        '''Invoke a QMP command and return the response dict'''
        qmp_args = dict()
        for key, value in args.iteritems():
            if conv_keys:
                qmp_args[key.replace('_', '-')] = value
            else:
                qmp_args[key] = value

        return self._qmp.cmd(cmd, args=qmp_args)

    def command(self, cmd, conv_keys=True, **args):
        '''
        Invoke a QMP command.
        On success return the response dict.
        On failure raise an exception.
        '''
        reply = self.qmp(cmd, conv_keys, **args)
        if reply is None:
            raise Exception("Monitor is closed")
        if "error" in reply:
            raise Exception(reply["error"]["desc"])
        return reply["return"]

    def get_qmp_event(self, wait=False):
        '''Poll for one queued QMP events and return it'''
        if len(self._events) > 0:
            return self._events.pop(0)
        return self._qmp.pull_event(wait=wait)

    def get_qmp_events(self, wait=False):
        '''Poll for queued QMP events and return a list of dicts'''
        events = self._qmp.get_events(wait=wait)
        events.extend(self._events)
        del self._events[:]
        self._qmp.clear_events()
        return events

    def event_wait(self, name, timeout=60.0, match=None):
        '''
        Wait for specified timeout on named event in QMP; optionally filter
        results by match.

        The 'match' is checked to be a recursive subset of the 'event'; skips
        branch processing on match's value None
           {"foo": {"bar": 1}} matches {"foo": None}
           {"foo": {"bar": 1}} does not matches {"foo": {"baz": None}}
        '''
        def event_match(event, match=None):
            if match is None:
                return True

            for key in match:
                if key in event:
                    if isinstance(event[key], dict):
                        if not event_match(event[key], match[key]):
                            return False
                    elif event[key] != match[key]:
                        return False
                else:
                    return False

            return True

        # Search cached events
        for event in self._events:
            if (event['event'] == name) and event_match(event, match):
                self._events.remove(event)
                return event

        # Poll for new events
        while True:
            event = self._qmp.pull_event(wait=timeout)
            if (event['event'] == name) and event_match(event, match):
                return event
            self._events.append(event)

        return None

    def get_log(self):
        '''
        After self.shutdown or failed qemu execution, this returns the output
        of the qemu process.
        '''
        return self._iolog