From 36d0fe65160d83cb065de9b6fe60114ee127d9f0 Mon Sep 17 00:00:00 2001 From: Tuguoyi Date: Tue, 8 Dec 2020 01:46:25 +0000 Subject: migration: Don't allow migration if vm is in POSTMIGRATE The following steps will cause qemu assertion failure: - pause vm by executing 'virsh suspend' - create external snapshot of memory and disk using 'virsh snapshot-create-as' - doing the above operation again will cause qemu crash The backtrace looks like: at /build/qemu-5.0/migration/savevm.c:1401 at /build/qemu-5.0/migration/savevm.c:1453 When the first migration completes, bs->open_flags will set BDRV_O_INACTIVE flag by bdrv_inactivate_all(), and during the second migration the bdrv_inactivate_recurse assert that the bs->open_flags is already BDRV_O_INACTIVE enabled which cause crash. As Vladimir suggested, this patch makes migrate_prepare check the state of vm and return error if it is in RUN_STATE_POSTMIGRATE state. Signed-off-by: Tuguoyi Message-Id: <6b704294ad2e405781c38fb38d68c744@h3c.com> Reviewed-by: Vladimir Sementsov-Ogievskiy Reported-by: Li Zhang Reviewed-by: Pankaj Gupta Signed-off-by: Dr. David Alan Gilbert --- migration/migration.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'migration') diff --git a/migration/migration.c b/migration/migration.c index e0dbde4091..f5d4a52c95 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2102,6 +2102,12 @@ static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc, return false; } + if (runstate_check(RUN_STATE_POSTMIGRATE)) { + error_setg(errp, "Can't migrate the vm that was paused due to " + "previous migration"); + return false; + } + if (migration_is_blocked(errp)) { return false; } -- cgit v1.2.3