# 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 subprocess import qmp.qmp import shutil import tempfile 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() self._name = name self._monitor_address = monitor_address self._vm_monitor = None self._qemu_log_path = None self._qemu_log_file = None 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 self._test_dir = test_dir self._temp_dir = None self._launched = False # 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.poll() is None def exitcode(self): if self._popen is None: return None return self._popen.poll() def get_pid(self): if not self.is_running(): return None return self._popen.pid def _load_io_log(self): if self._qemu_log_path is not None: 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._vm_monitor return ['-chardev', moncdev, '-mon', 'chardev=mon,mode=control', '-display', 'none', '-vga', 'none'] def _pre_launch(self): self._temp_dir = tempfile.mkdtemp(dir=self._test_dir) if self._monitor_address is not None: self._vm_monitor = self._monitor_address else: self._vm_monitor = os.path.join(self._temp_dir, self._name + "-monitor.sock") self._qemu_log_path = os.path.join(self._temp_dir, self._name + ".log") self._qemu_log_file = open(self._qemu_log_path, 'wb') self._qmp = qmp.qmp.QEMUMonitorProtocol(self._vm_monitor, server=True) def _post_launch(self): self._qmp.accept() def _post_shutdown(self): if self._qemu_log_file is not None: self._qemu_log_file.close() self._qemu_log_file = None self._qemu_log_path = None if self._temp_dir is not None: shutil.rmtree(self._temp_dir) self._temp_dir = None def launch(self): """ Launch the VM and make sure we cleanup and expose the command line/output in case of exception """ if self._launched: raise QEMUMachineError('VM already launched') self._iolog = None self._qemu_full_args = None try: self._launch() self._launched = True except: self.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 _launch(self): '''Launch the VM and establish a QMP connection''' devnull = open(os.path.devnull, 'rb') 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=self._qemu_log_file, stderr=subprocess.STDOUT, shell=False) self._post_launch() 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) self._launched = False 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