Commit 21794244 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi Committed by Max Reitz
Browse files

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: default avatarMax Reitz <mreitz@redhat.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180305155926.25858-1-stefanha@redhat.com
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent 39eaefce

tests/qemu-iotests/203

+11 −4
Original line number Diff line number Diff line
@@ -49,11 +49,18 @@ with iotests.FilePath('disk0.img') as disk0_img_path, \ 
                       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:

        vm.get_qmp_event(wait=60.0)

        result = vm.qmp('query-migrate')

        status = result.get('return', {}).get('status', None)

        if status == 'completed':

        event = vm.event_wait('MIGRATION')

        iotests.log(event, filters=[iotests.filter_qmp_event])

        if event['data']['status'] == 'completed':

            break

tests/qemu-iotests/203.out

+5 −0
Original line number Diff line number Diff line
@@ -2,5 +2,10 @@ Launching VM... 
Setting IOThreads...

{u'return': {}}

{u'return': {}}

Enabling migration QMP events...

{u'return': {}}

Starting migration...

{u'return': {}}

{u'timestamp': {u'seconds': 'SECS', u'microseconds': 'USECS'}, u'data': {u'status': u'setup'}, u'event': u'MIGRATION'}

{u'timestamp': {u'seconds': 'SECS', u'microseconds': 'USECS'}, u'data': {u'status': u'active'}, u'event': u'MIGRATION'}

{u'timestamp': {u'seconds': 'SECS', u'microseconds': 'USECS'}, u'data': {u'status': u'completed'}, u'event': u'MIGRATION'}