# 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 logging
import os
import sys
import subprocess
import qmp.qmp
LOG = logging.getLogger(__name__)
class QEMUMachineError(Exception):
"""
Exception called when an error in QEMUMachine happens.
"""
class MonitorResponseError(qmp.qmp.QMPError):
'''
Represents erroneous QMP monitor reply
'''
def __init__(self, reply):
try:
desc = reply["error"]["desc"]
except KeyError:
desc = reply
super(MonitorResponseError, self).__init__(desc)
self.reply = reply
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):
'''
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()"
@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._qmp = None
self._qemu_full_args = None
# just in case logging wasn't configured by the main script:
logging.basicConfig()
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:
raise QEMUMachineError("No path to socket_scm_helper set")
if not os.path.exists(self._socket_scm_helper):
raise QEMUMachineError("%s does not exist" %
self._socket_scm_helper)
fd_param = ["%s" % self._socket_scm_helper,
"%d" % self._qmp.get_sock_fd(),
"%s" % fd_file_path]
devnull = open(os.path.devnull, 'rb')
proc = subprocess.Popen(fd_param, stdin=devnull, stdout=subprocess.PIPE,
stderr=subprocess.STDOUT)
output = proc.communicate()[0]
if output:
LOG.debug(output)
return proc.returncode
@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 is not None 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)
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'''
self._iolog = None
self._qemu_full_args = None
devnull = open(os.path.devnull, 'rb')
qemulog = open(self._qemu_log_path, 'wb')
try:
self._pre_launch()
self._qemu_full_args = (self._wrapper + [self._binary] +
self._base_args() + self._args)
self._popen = subprocess.Popen(self._qemu_full_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()
LOG.debug('Error launching VM')
if self._qemu_full_args:
LOG.debug('Command: %r', ' '.join(self._qemu_full_args))
if self._iolog:
LOG.debug('Output: %r', self._iolog)
raise
def wait(self):
'''Wait for the VM to power off'''
self._popen.wait()
self._qmp.close()
self._load_io_log()
self._post_shutdown()
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()
self._popen.wait()
self._load_io_log()
self._post_shutdown()
exitcode = self.exitcode()
if exitcode is not None and exitcode < 0:
msg = 'qemu received signal %i: %s'
if self._qemu_full_args:
command = ' '.join(self._qemu_full_args)
else:
command = ''
LOG.warn(msg, exitcode, command)
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 qmp.qmp.QMPError("Monitor is closed")
if "error" in reply:
raise MonitorResponseError(reply)
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
