Re: [Qemu-devel] [PULL 1/3] Migration: Generate the completed event only when we complete

[Juan Quintela]

Christian Borntraeger <address@hidden> wrote:
> Am 15.10.2015 um 08:27 schrieb Juan Quintela:
>> From: "Dr. David Alan Gilbert" <address@hidden>
>> 
>> The current migration-completed event is generated a bit too early,
>> which means that an eager libvirt that's ready to go as soon
>> as it sees the event ends up racing with the actual end of migration.
>> 
>> This corresponds to RH bug:
>> https://bugzilla.redhat.com/show_bug.cgi?id=1271145
>
> Is that something for stable?

Yeap.


>
>
>> 
>> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
>> Reviewed-by: Juan Quintela <address@hidden>
>> Reviewed-by: Amit Shah <address@hidden>
>> xSigned-off-by: Juan Quintela <address@hidden>
>
>
>> ---
>>  migration/migration.c | 8 +++++++-
>>  1 file changed, 7 insertions(+), 1 deletion(-)
>> 
>> diff --git a/migration/migration.c b/migration/migration.c
>> index b7de9b7..3d40f24 100644
>> --- a/migration/migration.c
>> +++ b/migration/migration.c
>> @@ -294,12 +294,12 @@ static void process_incoming_migration_co(void *opaque)
>>          migrate_decompress_threads_join();
>>          exit(EXIT_FAILURE);
>>      }
>> -    migrate_generate_event(MIGRATION_STATUS_COMPLETED);
>>      qemu_announce_self();
>> 
>>      /* Make sure all file formats flush their mutable metadata */
>>      bdrv_invalidate_cache_all(&local_err);
>>      if (local_err) {
>> +        migrate_generate_event(MIGRATION_STATUS_FAILED);
>>          error_report_err(local_err);
>>          migrate_decompress_threads_join();
>>          exit(EXIT_FAILURE);
>> @@ -320,6 +320,12 @@ static void process_incoming_migration_co(void *opaque)
>>          runstate_set(global_state_get_runstate());
>>      }
>>      migrate_decompress_threads_join();
>> +    /*
>> +     * This must happen after any state changes since as soon as an external
>> +     * observer sees this event they might start to prod at the VM assuming
>> +     * it's ready to use.
>> +     */
>> +    migrate_generate_event(MIGRATION_STATUS_COMPLETED);
>>  }
>> 
>>  void process_incoming_migration(QEMUFile *f)
>>