migration: add is_active_iterate handler

Only-postcopy savevm states (dirty-bitmap) don't need live iteration, so
to disable them and stop transporting empty sections there is a new
savevm handler.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180313180320.339796-10-vsementsov@virtuozzo.com
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2018-03-13 15:34:01 -04:00 committed by John Snow
parent f0d64cb729
commit c865d84872
2 changed files with 14 additions and 0 deletions

View File

@ -26,6 +26,15 @@ typedef struct SaveVMHandlers {
bool (*is_active)(void *opaque);
bool (*has_postcopy)(void *opaque);
/* is_active_iterate
* If it is not NULL then qemu_savevm_state_iterate will skip iteration if
* it returns false. For example, it is needed for only-postcopy-states,
* which needs to be handled by qemu_savevm_state_setup and
* qemu_savevm_state_pending, but do not need iterations until not in
* postcopy stage.
*/
bool (*is_active_iterate)(void *opaque);
/* This runs outside the iothread lock in the migration case, and
* within the lock in the savevm case. The callback had better only
* use data that is local to the migration thread or protected

View File

@ -1028,6 +1028,11 @@ int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy)
continue;
}
}
if (se->ops && se->ops->is_active_iterate) {
if (!se->ops->is_active_iterate(se->opaque)) {
continue;
}
}
/*
* In the postcopy phase, any device that doesn't know how to
* do postcopy should have saved it's state in the _complete