ram_postcopy_send_discard_bitmap() performs the final RAM dirty bitmap
sync at postcopy switchover, before sending discard bitmap to the
destination. Unlike the precopy switchover path, it currently calls the
raw migration_bitmap_sync() helper and passes last_stage=false.
Postcopy switchover is also a stopped-VM final sync point, so use
migration_bitmap_sync_precopy(true). This keeps RAM final bitmap sync
handling consistent across precopy and postcopy switchover, including
the precopy bitmap-sync notifier wrapper. Current notifier users are
safe in postcopy: virtio-balloon free-page hinting already opts out when
postcopy-ram is enabled [1].
This prepares for moving the final sync out of RAM completion/discard
paths and into migration_switchover_start(), where the migration core
can run a final save_query_pending pass for all modules uniformly.
[1] fd51e54fa102 ("virtio-balloon: don't start free page hinting if postcopy is
possible")
Reviewed-by: Peter Xu <[email protected]>
Signed-off-by: Avihai Horon <[email protected]>
---
migration/ram.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/migration/ram.c b/migration/ram.c
index fc38ffbf8a..d7b8cc61ea 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2684,7 +2684,7 @@ void ram_postcopy_send_discard_bitmap(MigrationState *ms)
RCU_READ_LOCK_GUARD();
/* This should be our last sync, the src is now paused */
- migration_bitmap_sync(rs, false);
+ migration_bitmap_sync_precopy(true);
/* Easiest way to make sure we don't resume in the middle of a host-page */
rs->pss[RAM_CHANNEL_PRECOPY].last_sent_block = NULL;
--
2.40.1
