[Qemu-devel] [PATCH v2 0/5] dataplane snapshot fixes

["Denis V. Lunev" <den@openvz.org>]

The following test
    while /bin/true ; do
        virsh snapshot-create rhel7
        sleep 10
        virsh snapshot-delete rhel7 --current
    done
with enabled iothreads on a running VM leads to a lot of troubles: hangs,
asserts, errors.

Though (in general) HMP snapshot code is terrible. I think it should be
dropped at once and replaced with blkdev transactions code. Though is
could not fit to QEMU 2.5/stable at all.

Anyway, I think that the construction like
    assert(aio_context_is_locked(aio_context));
should be widely used to ensure proper locking.

Changes from v1:
- aio-context locking added
- comment is rewritten

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>

Denis V. Lunev (4):
  fifolock: create rfifolock_is_locked helper
  aio_context: create aio_context_is_locked helper
  io: add locking constraints check into bdrv_drain to ensure locking
  migration: add missed aio_context_acquire into hmp_savevm/hmp_delvm

Pavel Butsykin (1):
  virtio: sync the dataplane vring state to the virtqueue before
    virtio_save

 async.c                  | 5 +++++
 block/io.c               | 5 ++++-
 block/snapshot.c         | 5 +++++
 hw/block/virtio-blk.c    | 5 +++++
 hw/scsi/virtio-scsi.c    | 5 +++++
 include/block/aio.h      | 3 +++
 include/qemu/rfifolock.h | 1 +
 migration/savevm.c       | 7 +++++++
 util/rfifolock.c         | 9 +++++++--
 9 files changed, 42 insertions(+), 3 deletions(-)

-- 
2.1.4