From 49a608b8c22db72d47e7676ff9c3b87d1d408736 Mon Sep 17 00:00:00 2001 From: John Snow Date: Tue, 26 Oct 2021 13:56:06 -0400 Subject: python/machine: Handle QMP errors on close more meticulously To use the AQMP backend, Machine just needs to be a little more diligent about what happens when closing a QMP connection. The operation is no longer a freebie in the async world; it may return errors encountered in the async bottom half on incoming message receipt, etc. (AQMP's disconnect, ultimately, serves as the quiescence point where all async contexts are gathered together, and any final errors reported at that point.) Because async QMP continues to check for messages asynchronously, it's almost certainly likely that the loop will have exited due to EOF after issuing the last 'quit' command. That error will ultimately be bubbled up when attempting to close the QMP connection. The manager class here then is free to discard it -- if it was expected. Signed-off-by: John Snow Reviewed-by: Hanna Reitz Reviewed-by: Kevin Wolf Message-id: 20211026175612.4127598-3-jsnow@redhat.com Signed-off-by: John Snow --- python/qemu/machine/machine.py | 48 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 42 insertions(+), 6 deletions(-) (limited to 'python') diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py index 0bd40bc2f7..a0cf69786b 100644 --- a/python/qemu/machine/machine.py +++ b/python/qemu/machine/machine.py @@ -342,9 +342,15 @@ class QEMUMachine: # Comprehensive reset for the failed launch case: self._early_cleanup() - if self._qmp_connection: - self._qmp.close() - self._qmp_connection = None + try: + self._close_qmp_connection() + except Exception as err: # pylint: disable=broad-except + LOG.warning( + "Exception closing QMP connection: %s", + str(err) if str(err) else type(err).__name__ + ) + finally: + assert self._qmp_connection is None self._close_qemu_log_file() @@ -420,6 +426,31 @@ class QEMUMachine: close_fds=False) self._post_launch() + def _close_qmp_connection(self) -> None: + """ + Close the underlying QMP connection, if any. + + Dutifully report errors that occurred while closing, but assume + that any error encountered indicates an abnormal termination + process and not a failure to close. + """ + if self._qmp_connection is None: + return + + try: + self._qmp.close() + except EOFError: + # EOF can occur as an Exception here when using the Async + # QMP backend. It indicates that the server closed the + # stream. If we successfully issued 'quit' at any point, + # then this was expected. If the remote went away without + # our permission, it's worth reporting that as an abnormal + # shutdown case. + if not (self._user_killed or self._quit_issued): + raise + finally: + self._qmp_connection = None + def _early_cleanup(self) -> None: """ Perform any cleanup that needs to happen before the VM exits. @@ -460,9 +491,14 @@ class QEMUMachine: self._early_cleanup() if self._qmp_connection: - if not self._quit_issued: - # Might raise ConnectionReset - self.qmp('quit') + try: + if not self._quit_issued: + # May raise ExecInterruptedError or StateError if the + # connection dies or has *already* died. + self.qmp('quit') + finally: + # Regardless, we want to quiesce the connection. + self._close_qmp_connection() # May raise subprocess.TimeoutExpired self._subp.wait(timeout=timeout) -- cgit v1.2.3-55-g7522 href='#n20'>20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 
/*
 * QEMU PS/2 keyboard/mouse emulation
 *
 * Copyright (C) 2003 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef HW_PS2_H
#define HW_PS2_H

#define PS2_MOUSE_BUTTON_LEFT   0x01
#define PS2_MOUSE_BUTTON_RIGHT  0x02
#define PS2_MOUSE_BUTTON_MIDDLE 0x04
#define PS2_MOUSE_BUTTON_SIDE   0x08
#define PS2_MOUSE_BUTTON_EXTRA  0x10

typedef struct PS2State PS2State;

/* ps2.c */
void *ps2_kbd_init(void (*update_irq)(void *, int), void *update_arg);
void *ps2_mouse_init(void (*update_irq)(void *, int), void *update_arg);
void ps2_write_mouse(void *, int val);
void ps2_write_keyboard(void *, int val);
uint32_t ps2_read_data(PS2State *s);
void ps2_queue_noirq(PS2State *s, int b);
void ps2_raise_irq(PS2State *s);
void ps2_queue(PS2State *s, int b);
void ps2_queue_2(PS2State *s, int b1, int b2);
void ps2_queue_3(PS2State *s, int b1, int b2, int b3);
void ps2_queue_4(PS2State *s, int b1, int b2, int b3, int b4);
void ps2_keyboard_set_translation(void *opaque, int mode);
void ps2_mouse_fake_event(void *opaque);

#endif /* HW_PS2_H */