migration: simplify blockers

Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason.  This allows migration to own the Error object, so that if
an error occurs in migrate_add_blocker, migration code can free the Error
and clear the client handle, simplifying client code.  It also simplifies
the migrate_del_blocker call site.

In addition, this is a pre-requisite for a proposed future patch that would
add a mode argument to migration requests to support live update, and
maintain a list of blockers for each mode.  A blocker may apply to a single
mode or to multiple modes, and passing Error** will allow one Error object
to be registered for multiple modes.

No functional change.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Tested-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1697634216-84215-1-git-send-email-steven.sistare@oracle.com>
This commit is contained in:
Steve Sistare 2023-10-18 06:03:36 -07:00 committed by Juan Quintela
parent 04131e0009
commit c8a7fc5179
33 changed files with 92 additions and 150 deletions

View file

@ -891,8 +891,6 @@ static void vfio_migration_deinit(VFIODevice *vbasedev)
static int vfio_block_migration(VFIODevice *vbasedev, Error *err, Error **errp)
{
int ret;
if (vbasedev->enable_migration == ON_OFF_AUTO_ON) {
error_propagate(errp, err);
return -EINVAL;
@ -901,13 +899,7 @@ static int vfio_block_migration(VFIODevice *vbasedev, Error *err, Error **errp)
vbasedev->migration_blocker = error_copy(err);
error_free(err);
ret = migrate_add_blocker(vbasedev->migration_blocker, errp);
if (ret < 0) {
error_free(vbasedev->migration_blocker);
vbasedev->migration_blocker = NULL;
}
return ret;
return migrate_add_blocker(&vbasedev->migration_blocker, errp);
}
/* ---------------------------------------------------------------------- */
@ -994,9 +986,5 @@ void vfio_migration_exit(VFIODevice *vbasedev)
vfio_migration_deinit(vbasedev);
}
if (vbasedev->migration_blocker) {
migrate_del_blocker(vbasedev->migration_blocker);
error_free(vbasedev->migration_blocker);
vbasedev->migration_blocker = NULL;
}
migrate_del_blocker(&vbasedev->migration_blocker);
}