qemu/tests/qemu-iotests/203
Stefan Hajnoczi 21794244d4 qemu-iotests: fix 203 migration completion race
There is a race between the test's 'query-migrate' QMP command after the
QMP 'STOP' event and completing the migration:

The test case invokes 'query-migrate' upon receiving 'STOP'.  At this
point the migration thread may still be in the process of completing.
Therefore 'query-migrate' can return 'status': 'active' for a brief
window of time instead of 'status': 'completed'.  This results in
qemu-iotests 203 hanging.

Solve the race by enabling the 'events' migration capability, which
causes QEMU to emit migration-specific QMP events that do not suffer
from this race condition.  Wait for the QMP 'MIGRATION' event with
'status': 'completed'.

Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180305155926.25858-1-stefanha@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-03-09 15:40:07 +01:00

67 lines
2.5 KiB
Python
Executable File

#!/usr/bin/env python
#
# Copyright (C) 2017 Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# Creator/Owner: Stefan Hajnoczi <stefanha@redhat.com>
#
# Check that QMP 'migrate' with multiple drives on a single IOThread completes
# successfully. This particular command triggered a hang in the source QEMU
# process due to recursive AioContext locking in bdrv_invalidate_all() and
# BDRV_POLL_WHILE().
import iotests
iotests.verify_image_format(supported_fmts=['qcow2'])
iotests.verify_platform(['linux'])
with iotests.FilePath('disk0.img') as disk0_img_path, \
iotests.FilePath('disk1.img') as disk1_img_path, \
iotests.VM() as vm:
img_size = '10M'
iotests.qemu_img_pipe('create', '-f', iotests.imgfmt, disk0_img_path, img_size)
iotests.qemu_img_pipe('create', '-f', iotests.imgfmt, disk1_img_path, img_size)
iotests.log('Launching VM...')
(vm.add_object('iothread,id=iothread0')
.add_drive(disk0_img_path, 'node-name=drive0-node', interface='none')
.add_drive(disk1_img_path, 'node-name=drive1-node', interface='none')
.launch())
iotests.log('Setting IOThreads...')
iotests.log(vm.qmp('x-blockdev-set-iothread',
node_name='drive0-node', iothread='iothread0',
force=True))
iotests.log(vm.qmp('x-blockdev-set-iothread',
node_name='drive1-node', iothread='iothread0',
force=True))
iotests.log('Enabling migration QMP events...')
iotests.log(vm.qmp('migrate-set-capabilities', capabilities=[
{
'capability': 'events',
'state': True
}
]))
iotests.log('Starting migration...')
iotests.log(vm.qmp('migrate', uri='exec:cat >/dev/null'))
while True:
event = vm.event_wait('MIGRATION')
iotests.log(event, filters=[iotests.filter_qmp_event])
if event['data']['status'] == 'completed':
break