Re: [Qemu-devel] [PATCH] qemu-iotests: fix 203 migration completion race

[Max Reitz <mreitz@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 1093 bytes --]

On 2018-03-05 16:59, Stefan Hajnoczi wrote:
> 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>
> ---
>  tests/qemu-iotests/203     | 15 +++++++++++----
>  tests/qemu-iotests/203.out |  5 +++++
>  2 files changed, 16 insertions(+), 4 deletions(-)

So much for "the ppoll() dungeon"...

Thanks!

Reviewed-by: Max Reitz <mreitz@redhat.com>


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 512 bytes --]