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: #0 0x00007fbf958c5c37 in raise () from /lib/x86_64-linux-gnu/libc.so.6 #1 0x00007fbf958c9028 in abort () from /lib/x86_64-linux-gnu/libc.so.6 #2 0x00007fbf958bebf6 in ?? () from /lib/x86_64-linux-gnu/libc.so.6 #3 0x00007fbf958beca2 in __assert_fail () from /lib/x86_64-linux-gnu/libc.so.6 #4 0x000055ca8decd39d in bdrv_inactivate_recurse (bs=0x55ca90c80400) at /build/qemu-5.0/block.c:5724 #5 0x000055ca8dece967 in bdrv_inactivate_all () at /build//qemu-5.0/block.c:5792 #6 0x000055ca8de5539d in qemu_savevm_state_complete_precopy_non_iterable (inactivate_disks=true, in_postcopy=false, f=0x55ca907044b0) at /build/qemu-5.0/migration/savevm.c:1401 #7 qemu_savevm_state_complete_precopy (f=0x55ca907044b0, iterable_only=iterable_only@entry=false, inactivate_disks=inactivate_disks@entry=true) at /build/qemu-5.0/migration/savevm.c:1453 #8 0x000055ca8de4f581 in migration_completion (s=0x55ca8f64d9f0) at /build/qemu-5.0/migration/migration.c:2941 #9 migration_iteration_run (s=0x55ca8f64d9f0) at /build/qemu-5.0/migration/migration.c:3295 #10 migration_thread (opaque=opaque@entry=0x55ca8f64d9f0) at /build/qemu-5.0/migration/migration.c:3459 #11 0x000055ca8dfc6716 in qemu_thread_start (args=<optimized out>) at /build/qemu-5.0/util/qemu-thread-posix.c:519 #12 0x00007fbf95c5f184 in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0 #13 0x00007fbf9598cbed in clone () from /lib/x86_64-linux-gnu/libc.so.6 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 <tu.gu...@h3c.com> --- migration/migration.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/migration/migration.c b/migration/migration.c index 87a9b59..5e33962 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2115,6 +2115,12 @@ 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; } -- 2.7.4 [Patch v2]: https://lists.gnu.org/archive/html/qemu-devel/2020-12/msg01318.html [Patch v1]: https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg05950.html