| """ |
| QEMU machine module: |
| |
| The machine module primarily provides the QEMUMachine class, |
| which provides facilities for managing the lifetime of a QEMU VM. |
| """ |
| |
| # 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 shutil |
| import signal |
| import tempfile |
| from typing import Optional, Type |
| from types import TracebackType |
| from . import console_socket |
| |
| from . import qmp |
| |
| LOG = logging.getLogger(__name__) |
| |
| |
| class QEMUMachineError(Exception): |
| """ |
| Exception called when an error in QEMUMachine happens. |
| """ |
| |
| |
| class QEMUMachineAddDeviceError(QEMUMachineError): |
| """ |
| Exception raised when a request to add a device can not be fulfilled |
| |
| The failures are caused by limitations, lack of information or conflicting |
| requests on the QEMUMachine methods. This exception does not represent |
| failures reported by the QEMU binary itself. |
| """ |
| |
| |
| class AbnormalShutdown(QEMUMachineError): |
| """ |
| Exception raised when a graceful shutdown was requested, but not performed. |
| """ |
| |
| |
| class QEMUMachine: |
| """ |
| 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, sock_dir=None, |
| drain_console=False, console_log=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() |
| @param sock_dir: where to create socket (overrides test_dir for sock) |
| @param console_log: (optional) path to console log file |
| @param drain_console: (optional) True to drain console socket to buffer |
| @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 sock_dir is None: |
| sock_dir = test_dir |
| 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_set = True # Enable QMP monitor by default. |
| self._qmp = None |
| self._qemu_full_args = None |
| self._test_dir = test_dir |
| self._temp_dir = None |
| self._sock_dir = sock_dir |
| self._launched = False |
| self._machine = None |
| self._console_index = 0 |
| self._console_set = False |
| self._console_device_type = None |
| self._console_address = None |
| self._console_socket = None |
| self._remove_files = [] |
| self._user_killed = False |
| self._console_log_path = console_log |
| if self._console_log_path: |
| # In order to log the console, buffering needs to be enabled. |
| self._drain_console = True |
| else: |
| self._drain_console = drain_console |
| |
| def __enter__(self): |
| return self |
| |
| def __exit__(self, |
| exc_type: Optional[Type[BaseException]], |
| exc_val: Optional[BaseException], |
| exc_tb: Optional[TracebackType]) -> None: |
| self.shutdown() |
| |
| def add_monitor_null(self): |
| """ |
| This can be used to add an unused monitor instance. |
| """ |
| self._args.append('-monitor') |
| self._args.append('null') |
| |
| 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) |
| |
| # This did not exist before 3.4, but since then it is |
| # mandatory for our purpose |
| if hasattr(os, 'set_inheritable'): |
| os.set_inheritable(fd, True) |
| |
| self._args.append('-add-fd') |
| self._args.append(','.join(options)) |
| return self |
| |
| def send_fd_scm(self, fd=None, file_path=None): |
| """ |
| Send an fd or file_path to socket_scm_helper. |
| |
| Exactly one of fd and file_path must be given. |
| If it is file_path, the helper will open that file and pass its own fd. |
| """ |
| # 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) |
| |
| # This did not exist before 3.4, but since then it is |
| # mandatory for our purpose |
| if hasattr(os, 'set_inheritable'): |
| os.set_inheritable(self._qmp.get_sock_fd(), True) |
| if fd is not None: |
| os.set_inheritable(fd, True) |
| |
| fd_param = ["%s" % self._socket_scm_helper, |
| "%d" % self._qmp.get_sock_fd()] |
| |
| if file_path is not None: |
| assert fd is None |
| fd_param.append(file_path) |
| else: |
| assert fd is not None |
| fd_param.append(str(fd)) |
| |
| devnull = open(os.path.devnull, 'rb') |
| proc = subprocess.Popen( |
| fd_param, stdin=devnull, stdout=subprocess.PIPE, |
| stderr=subprocess.STDOUT, close_fds=False |
| ) |
| 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): |
| """Returns true if the VM is running.""" |
| return self._popen is not None and self._popen.poll() is None |
| |
| def exitcode(self): |
| """Returns the exit code if possible, or None.""" |
| if self._popen is None: |
| return None |
| return self._popen.poll() |
| |
| def get_pid(self): |
| """Returns the PID of the running process, or None.""" |
| 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): |
| args = ['-display', 'none', '-vga', 'none'] |
| if self._qmp_set: |
| 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 |
| args.extend(['-chardev', moncdev, '-mon', |
| 'chardev=mon,mode=control']) |
| if self._machine is not None: |
| args.extend(['-machine', self._machine]) |
| for _ in range(self._console_index): |
| args.extend(['-serial', 'null']) |
| if self._console_set: |
| self._console_address = os.path.join(self._sock_dir, |
| self._name + "-console.sock") |
| self._remove_files.append(self._console_address) |
| chardev = ('socket,id=console,path=%s,server,nowait' % |
| self._console_address) |
| args.extend(['-chardev', chardev]) |
| if self._console_device_type is None: |
| args.extend(['-serial', 'chardev:console']) |
| else: |
| device = '%s,chardev=console' % self._console_device_type |
| args.extend(['-device', device]) |
| return args |
| |
| def _pre_launch(self): |
| self._temp_dir = tempfile.mkdtemp(dir=self._test_dir) |
| self._qemu_log_path = os.path.join(self._temp_dir, self._name + ".log") |
| self._qemu_log_file = open(self._qemu_log_path, 'wb') |
| |
| if self._qmp_set: |
| if self._monitor_address is not None: |
| self._vm_monitor = self._monitor_address |
| else: |
| self._vm_monitor = os.path.join(self._sock_dir, |
| self._name + "-monitor.sock") |
| self._remove_files.append(self._vm_monitor) |
| self._qmp = qmp.QEMUMonitorProtocol(self._vm_monitor, server=True, |
| nickname=self._name) |
| |
| def _post_launch(self): |
| if self._qmp: |
| self._qmp.accept() |
| |
| def _post_shutdown(self): |
| """ |
| Called to cleanup the VM instance after the process has exited. |
| May also be called after a failed launch. |
| """ |
| # Comprehensive reset for the failed launch case: |
| self._early_cleanup() |
| |
| if self._qmp: |
| self._qmp.close() |
| self._qmp = None |
| |
| self._load_io_log() |
| |
| 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 |
| |
| while len(self._remove_files) > 0: |
| self._remove_if_exists(self._remove_files.pop()) |
| |
| exitcode = self.exitcode() |
| if (exitcode is not None and exitcode < 0 |
| and not (self._user_killed and exitcode == -signal.SIGKILL)): |
| msg = 'qemu received signal %i; command: "%s"' |
| if self._qemu_full_args: |
| command = ' '.join(self._qemu_full_args) |
| else: |
| command = '' |
| LOG.warning(msg, -int(exitcode), command) |
| |
| self._user_killed = False |
| self._launched = False |
| |
| 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._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 _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) |
| LOG.debug('VM launch command: %r', ' '.join(self._qemu_full_args)) |
| self._popen = subprocess.Popen(self._qemu_full_args, |
| stdin=devnull, |
| stdout=self._qemu_log_file, |
| stderr=subprocess.STDOUT, |
| shell=False, |
| close_fds=False) |
| self._post_launch() |
| |
| def _early_cleanup(self) -> None: |
| """ |
| Perform any cleanup that needs to happen before the VM exits. |
| |
| May be invoked by both soft and hard shutdown in failover scenarios. |
| Called additionally by _post_shutdown for comprehensive cleanup. |
| """ |
| # If we keep the console socket open, we may deadlock waiting |
| # for QEMU to exit, while QEMU is waiting for the socket to |
| # become writeable. |
| if self._console_socket is not None: |
| self._console_socket.close() |
| self._console_socket = None |
| |
| def _hard_shutdown(self) -> None: |
| """ |
| Perform early cleanup, kill the VM, and wait for it to terminate. |
| |
| :raise subprocess.Timeout: When timeout is exceeds 60 seconds |
| waiting for the QEMU process to terminate. |
| """ |
| self._early_cleanup() |
| self._popen.kill() |
| self._popen.wait(timeout=60) |
| |
| def _soft_shutdown(self, timeout: Optional[int], |
| has_quit: bool = False) -> None: |
| """ |
| Perform early cleanup, attempt to gracefully shut down the VM, and wait |
| for it to terminate. |
| |
| :param timeout: Timeout in seconds for graceful shutdown. |
| A value of None is an infinite wait. |
| :param has_quit: When True, don't attempt to issue 'quit' QMP command |
| |
| :raise ConnectionReset: On QMP communication errors |
| :raise subprocess.TimeoutExpired: When timeout is exceeded waiting for |
| the QEMU process to terminate. |
| """ |
| self._early_cleanup() |
| |
| if self._qmp is not None: |
| if not has_quit: |
| # Might raise ConnectionReset |
| self._qmp.cmd('quit') |
| |
| # May raise subprocess.TimeoutExpired |
| self._popen.wait(timeout=timeout) |
| |
| def _do_shutdown(self, timeout: Optional[int], |
| has_quit: bool = False) -> None: |
| """ |
| Attempt to shutdown the VM gracefully; fallback to a hard shutdown. |
| |
| :param timeout: Timeout in seconds for graceful shutdown. |
| A value of None is an infinite wait. |
| :param has_quit: When True, don't attempt to issue 'quit' QMP command |
| |
| :raise AbnormalShutdown: When the VM could not be shut down gracefully. |
| The inner exception will likely be ConnectionReset or |
| subprocess.TimeoutExpired. In rare cases, non-graceful termination |
| may result in its own exceptions, likely subprocess.TimeoutExpired. |
| """ |
| try: |
| self._soft_shutdown(timeout, has_quit) |
| except Exception as exc: |
| self._hard_shutdown() |
| raise AbnormalShutdown("Could not perform graceful shutdown") \ |
| from exc |
| |
| def shutdown(self, has_quit: bool = False, |
| hard: bool = False, |
| timeout: Optional[int] = 30) -> None: |
| """ |
| Terminate the VM (gracefully if possible) and perform cleanup. |
| Cleanup will always be performed. |
| |
| If the VM has not yet been launched, or shutdown(), wait(), or kill() |
| have already been called, this method does nothing. |
| |
| :param has_quit: When true, do not attempt to issue 'quit' QMP command. |
| :param hard: When true, do not attempt graceful shutdown, and |
| suppress the SIGKILL warning log message. |
| :param timeout: Optional timeout in seconds for graceful shutdown. |
| Default 30 seconds, A `None` value is an infinite wait. |
| """ |
| if not self._launched: |
| return |
| |
| try: |
| if hard: |
| self._user_killed = True |
| self._hard_shutdown() |
| else: |
| self._do_shutdown(timeout, has_quit) |
| finally: |
| self._post_shutdown() |
| |
| def kill(self): |
| """ |
| Terminate the VM forcefully, wait for it to exit, and perform cleanup. |
| """ |
| self.shutdown(hard=True) |
| |
| def wait(self, timeout: Optional[int] = 30) -> None: |
| """ |
| Wait for the VM to power off and perform post-shutdown cleanup. |
| |
| :param timeout: Optional timeout in seconds. Default 30 seconds. |
| A value of `None` is an infinite wait. |
| """ |
| self.shutdown(has_quit=True, timeout=timeout) |
| |
| def set_qmp_monitor(self, enabled=True): |
| """ |
| Set the QMP monitor. |
| |
| @param enabled: if False, qmp monitor options will be removed from |
| the base arguments of the resulting QEMU command |
| line. Default is True. |
| @note: call this function before launch(). |
| """ |
| if enabled: |
| self._qmp_set = True |
| else: |
| self._qmp_set = False |
| self._qmp = None |
| |
| 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.items(): |
| 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.QMPError("Monitor is closed") |
| if "error" in reply: |
| raise qmp.QMPResponseError(reply) |
| return reply["return"] |
| |
| def get_qmp_event(self, wait=False): |
| """ |
| Poll for one queued QMP events and return it |
| """ |
| if self._events: |
| 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 |
| |
| @staticmethod |
| def event_match(event, match=None): |
| """ |
| Check if an event matches optional match criteria. |
| |
| The match criteria takes the form of a matching subdict. The event is |
| checked to be a superset of the subdict, recursively, with matching |
| values whenever the subdict values are not None. |
| |
| This has a limitation that you cannot explicitly check for None values. |
| |
| Examples, with the subdict queries on the left: |
| - None matches any object. |
| - {"foo": None} matches {"foo": {"bar": 1}} |
| - {"foo": None} matches {"foo": 5} |
| - {"foo": {"abc": None}} does not match {"foo": {"bar": 1}} |
| - {"foo": {"rab": 2}} matches {"foo": {"bar": 1, "rab": 2}} |
| """ |
| if match is None: |
| return True |
| |
| try: |
| for key in match: |
| if key in event: |
| if not QEMUMachine.event_match(event[key], match[key]): |
| return False |
| else: |
| return False |
| return True |
| except TypeError: |
| # either match or event wasn't iterable (not a dict) |
| return match == event |
| |
| def event_wait(self, name, timeout=60.0, match=None): |
| """ |
| event_wait waits for and returns a named event from QMP with a timeout. |
| |
| name: The event to wait for. |
| timeout: QEMUMonitorProtocol.pull_event timeout parameter. |
| match: Optional match criteria. See event_match for details. |
| """ |
| return self.events_wait([(name, match)], timeout) |
| |
| def events_wait(self, events, timeout=60.0): |
| """ |
| events_wait waits for and returns a named event |
| from QMP with a timeout. |
| |
| events: a sequence of (name, match_criteria) tuples. |
| The match criteria are optional and may be None. |
| See event_match for details. |
| timeout: QEMUMonitorProtocol.pull_event timeout parameter. |
| """ |
| def _match(event): |
| for name, match in events: |
| if event['event'] == name and self.event_match(event, match): |
| return True |
| return False |
| |
| # Search cached events |
| for event in self._events: |
| if _match(event): |
| self._events.remove(event) |
| return event |
| |
| # Poll for new events |
| while True: |
| event = self._qmp.pull_event(wait=timeout) |
| if _match(event): |
| 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 |
| |
| def add_args(self, *args): |
| """ |
| Adds to the list of extra arguments to be given to the QEMU binary |
| """ |
| self._args.extend(args) |
| |
| def set_machine(self, machine_type): |
| """ |
| Sets the machine type |
| |
| If set, the machine type will be added to the base arguments |
| of the resulting QEMU command line. |
| """ |
| self._machine = machine_type |
| |
| def set_console(self, device_type=None, console_index=0): |
| """ |
| Sets the device type for a console device |
| |
| If set, the console device and a backing character device will |
| be added to the base arguments of the resulting QEMU command |
| line. |
| |
| This is a convenience method that will either use the provided |
| device type, or default to a "-serial chardev:console" command |
| line argument. |
| |
| The actual setting of command line arguments will be be done at |
| machine launch time, as it depends on the temporary directory |
| to be created. |
| |
| @param device_type: the device type, such as "isa-serial". If |
| None is given (the default value) a "-serial |
| chardev:console" command line argument will |
| be used instead, resorting to the machine's |
| default device type. |
| @param console_index: the index of the console device to use. |
| If not zero, the command line will create |
| 'index - 1' consoles and connect them to |
| the 'null' backing character device. |
| """ |
| self._console_set = True |
| self._console_device_type = device_type |
| self._console_index = console_index |
| |
| @property |
| def console_socket(self): |
| """ |
| Returns a socket connected to the console |
| """ |
| if self._console_socket is None: |
| self._console_socket = console_socket.ConsoleSocket( |
| self._console_address, |
| file=self._console_log_path, |
| drain=self._drain_console) |
| return self._console_socket |
