On Tue, Nov 20, 2018 at 11:53:00AM -0500, Wainer dos Santos Moschetta wrote:
> QEMUMachine launches the VM with a monitor enabled, afterwards
> a qmp connection is attempted on _post_launch(). In case
> the QEMU process exits with an error, qmp.accept() reaches
> timeout and raises an exception.
>
> But sometimes you don't need that monitor. As an example,
> when a test launches the VM expects its immediate crash,
> and only intend to check the process's return code. In this
> case the fact that launch() tries to establish the qmp
> connection (ending up in an exception) is troublesome.
>
> So this patch adds the disable_qmp() that allow to
> launch the VM without creating the monitor machinery.
>
> Tested this change with the following Avocado test:
>
> from avocado_qemu import Test
> class DisableQmp(Test):
> """
> :avocado: enable
> """
> def test(self):
> self.vm.add_args('--foobar')
> self.vm.disable_qmp()
> self.vm.launch()
> self.vm.wait()
> self.assertEqual(self.vm.exitcode(), 1)
>
> Signed-off-by: Wainer dos Santos Moschetta <waine...@redhat.com>
[...]
> ---
> scripts/qemu.py | 58 ++++++++++++++++++++++++++++++++-----------------
> 1 file changed, 38 insertions(+), 20 deletions(-)
>
> diff --git a/scripts/qemu.py b/scripts/qemu.py
> index 6e3b0e6771..bbe80ac601 100644
> --- a/scripts/qemu.py
> +++ b/scripts/qemu.py
> @@ -115,6 +115,7 @@ class QEMUMachine(object):
> self._events = []
> self._iolog = None
> self._socket_scm_helper = socket_scm_helper
> + self._with_qmp = True # Enable QMP by default.
> self._qmp = None
> self._qemu_full_args = None
> self._test_dir = test_dir
> @@ -229,15 +230,7 @@ class QEMUMachine(object):
> 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
> - args = ['-chardev', moncdev,
> - '-mon', 'chardev=mon,mode=control',
> - '-display', 'none', '-vga', 'none']
> + args = ['-display', 'none', '-vga', 'none']
> if self._machine is not None:
> args.extend(['-machine', self._machine])
> if self._console_device_type is not None:
> @@ -249,21 +242,35 @@ class QEMUMachine(object):
> args.extend(['-chardev', chardev, '-device', device])
> return args
>
> - def _pre_launch(self):
> - self._temp_dir = tempfile.mkdtemp(dir=self._test_dir)
> + def _setup_qmp(self):
> +
> 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')
>
> + 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
> +
> + self._args.extend(['-chardev', moncdev, '-mon',
> 'chardev=mon,mode=control'])
This will extend self._args multiple times if making a
.shutdown()/.launch() cycle:
$ cat scripts/test.py
import qemu
import logging, sys
logging.basicConfig(stream=sys.stderr, level=logging.DEBUG)
vm = qemu.QEMUMachine('./x86_64-softmmu/qemu-system-x86_64')
vm.launch()
vm.shutdown()
vm.launch()
vm.shutdown()
$ python3 scripts/test.py
DEBUG:QMP:>>> {'execute': 'qmp_capabilities'}
DEBUG:QMP:<<< {'return': {}}
DEBUG:QMP:>>> {'execute': 'quit'}
DEBUG:QMP:<<< {'return': {}}
^CDEBUG:qemu:Error launching VM
DEBUG:qemu:Command: './x86_64-softmmu/qemu-system-x86_64 -display none -vga
none -chardev socket,id=mon,path=/var/tmp/tmpzny4hpy5/qemu-13737-monitor.sock
-mon chardev=mon,mode=control -chardev
socket,id=mon,path=/var/tmp/tmpkrlv1d9w/qemu-13737-monitor.sock -mon
chardev=mon,mode=control'
DEBUG:qemu:Output: "qemu-system-x86_64: -chardev
socket,id=mon,path=/var/tmp/tmpkrlv1d9w/qemu-13737-monitor.sock: Duplicate ID
'mon' for chardev\n"
Traceback (most recent call last):
File "scripts/test.py", line 7, in <module>
vm.launch()
File "/home/ehabkost/rh/proj/virt/qemu/scripts/qemu.py", line 302, in launch
self._launch()
File "/home/ehabkost/rh/proj/virt/qemu/scripts/qemu.py", line 328, in
_launch
self._post_launch()
File "/home/ehabkost/rh/proj/virt/qemu/scripts/qemu.py", line 273, in
_post_launch
self._qmp.accept()
File "/home/ehabkost/rh/proj/virt/qemu/scripts/qmp/qmp.py", line 155, in
accept
self.__sock, _ = self.__sock.accept()
File "/usr/lib64/python3.6/socket.py", line 205, in accept
fd, addr = self._accept()
KeyboardInterrupt
Why did you move this code outside _base_args(), where it already
worked without relying on method side-effects and required no
extra state to be kept inside self._args?
> self._qmp = qmp.qmp.QEMUMonitorProtocol(self._vm_monitor,
> server=True)
>
> + def _pre_launch(self):
> + self._temp_dir = tempfile.mkdtemp(dir=self._test_dir)
> + if self._with_qmp:
> + self._setup_qmp()
> + self._qemu_log_path = os.path.join(self._temp_dir, self._name +
> ".log")
> + self._qemu_log_file = open(self._qemu_log_path, 'wb')
> +
> def _post_launch(self):
> - self._qmp.accept()
> + if self._qmp:
> + self._qmp.accept()
>
> def _post_shutdown(self):
> if self._qemu_log_file is not None:
> @@ -325,7 +332,8 @@ class QEMUMachine(object):
> Wait for the VM to power off
> """
> self._popen.wait()
> - self._qmp.close()
> + if self._qmp:
> + self._qmp.close()
> self._load_io_log()
> self._post_shutdown()
>
> @@ -334,11 +342,14 @@ class QEMUMachine(object):
> Terminate the VM and clean up
> """
> if self.is_running():
> - try:
> - self._qmp.cmd('quit')
> - self._qmp.close()
> - except:
> - self._popen.kill()
> + if self._qmp:
> + try:
> + self._qmp.cmd('quit')
> + self._qmp.close()
> + except:
> + self._popen.kill()
> + else:
> + self._popen.terminate()
> self._popen.wait()
>
> self._load_io_log()
> @@ -355,6 +366,13 @@ class QEMUMachine(object):
>
> self._launched = False
>
> + def disable_qmp(self):
> + """
> + Disable the QMP monitor.
> + @note: call this function before launch().
> + """
> + self._with_qmp = False
> +
> def qmp(self, cmd, conv_keys=True, **args):
> """
> Invoke a QMP command and return the response dict
> --
> 2.19.1
>
--
Eduardo
