migration: restore vmstate on migration failure

1. Otherwise failed migration just drops guest-panicked state, which is
   not good for management software.

2. We do keep different paused states like guest-panicked during
   migration with help of global_state state.

3. We do restore running state on source when migration is cancelled or
   failed.

4. "postmigrate" state is documented as "guest is paused following a
   successful 'migrate'", so originally it's only for successful path
   and we never documented current behavior.

Let's restore paused states like guest-panicked in case of cancel or
fail too. Allow same transitions like for inmigrate state.

This commit changes the behavior that was introduced by commit
42da5550d6 "migration: set state to post-migrate on failure" and
provides a bit different fix on related
  https://bugzilla.redhat.com/show_bug.cgi?id=1355683

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230517123752.21615-6-vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
master
Vladimir Sementsov-Ogievskiy 2023-05-17 15:37:52 +03:00 committed by Juan Quintela
parent f4584076fc
commit a4c6275aa1
2 changed files with 8 additions and 2 deletions

View File

@ -2772,7 +2772,7 @@ static void migration_iteration_finish(MigrationState *s)
}
} else {
if (runstate_check(RUN_STATE_FINISH_MIGRATE)) {
runstate_set(RUN_STATE_POSTMIGRATE);
runstate_set(s->vm_old_state);
}
}
break;

View File

@ -121,7 +121,13 @@ static const RunStateTransition runstate_transitions_def[] = {
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_PAUSED },
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_POSTMIGRATE },
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_PRELAUNCH },
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_COLO},
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_COLO },
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_INTERNAL_ERROR },
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_IO_ERROR },
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_SHUTDOWN },
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_SUSPENDED },
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_WATCHDOG },
{ RUN_STATE_FINISH_MIGRATE, RUN_STATE_GUEST_PANICKED },
{ RUN_STATE_RESTORE_VM, RUN_STATE_RUNNING },
{ RUN_STATE_RESTORE_VM, RUN_STATE_PRELAUNCH },