> 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> Similar issue is reported by Li Zhang(+CC) with almost same patch[3] to fix this.
Reported-by: Li Zhang <li.zh...@cloud.ionos.com> Reviewed-by: Pankaj Gupta <pankaj.gu...@cloud.ionos.com> [3] https://marc.info/?l=qemu-devel&m=160749859831357&w=2 > --- > 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
