From edd090c72825b483df4de6a525d430d7635a5d8e Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Wed, 2 May 2018 18:47:32 +0800 Subject: migration: synchronize dirty bitmap for resume This patch implements the first part of core RAM resume logic for postcopy. ram_resume_prepare() is provided for the work. When the migration is interrupted by network failure, the dirty bitmap on the source side will be meaningless, because even the dirty bit is cleared, it is still possible that the sent page was lost along the way to destination. Here instead of continue the migration with the old dirty bitmap on source, we ask the destination side to send back its received bitmap, then invert it to be our initial dirty bitmap. The source side send thread will issue the MIG_CMD_RECV_BITMAP requests, once per ramblock, to ask for the received bitmap. On destination side, MIG_RP_MSG_RECV_BITMAP will be issued, along with the requested bitmap. Data will be received on the return-path thread of source, and the main migration thread will be notified when all the ramblock bitmaps are synchronized. Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Peter Xu Message-Id: <20180502104740.12123-17-peterx@redhat.com> Signed-off-by: Juan Quintela --- migration/migration.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'migration/migration.c') diff --git a/migration/migration.c b/migration/migration.c index b0217c4823..19ef8b05b1 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2967,6 +2967,7 @@ static void migration_instance_finalize(Object *obj) qemu_sem_destroy(&ms->pause_sem); qemu_sem_destroy(&ms->postcopy_pause_sem); qemu_sem_destroy(&ms->postcopy_pause_rp_sem); + qemu_sem_destroy(&ms->rp_state.rp_sem); error_free(ms->error); } @@ -2999,6 +3000,7 @@ static void migration_instance_init(Object *obj) qemu_sem_init(&ms->postcopy_pause_sem, 0); qemu_sem_init(&ms->postcopy_pause_rp_sem, 0); + qemu_sem_init(&ms->rp_state.rp_sem, 0); } /* -- cgit v1.2.3