qemu/scripts/qemu.py

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# 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 string
import os
import sys
import subprocess
import qmp.qmp
class QEMUMachine(object):
'''A QEMU VM'''
def __init__(self, binary, args=[], wrapper=[], name=None, test_dir="/var/tmp",
monitor_address=None, socket_scm_helper=None, debug=False):
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
# 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 os.path.exists(self._socket_scm_helper) == False:
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')
p = subprocess.Popen(fd_param, stdin=devnull, stdout=sys.stdout,
stderr=sys.stderr)
return p.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 fh:
self._iolog = fh.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()
underscore_to_dash = string.maketrans('_', '-')
def qmp(self, cmd, conv_keys=True, **args):
'''Invoke a QMP command and return the result dict'''
qmp_args = dict()
for k in args.keys():
if conv_keys:
qmp_args[k.translate(self.underscore_to_dash)] = args[k]
else:
qmp_args[k] = args[k]
return self._qmp.cmd(cmd, args=qmp_args)
def command(self, cmd, conv_keys=True, **args):
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):
# Test if 'match' is a recursive subset of 'event'
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):
return self._iolog