This set of patches includes several fixes for preserving
the state of the block device images while recording and replaying
virtual machine execution.

blkreplay driver now creates temporary overlay for underlaying devices
This patch implicitly enables '-snapshot' behavior in record/replay mode.
blkreplay layer creates temporary overlays on top of underlaying
disk images. It is needed, because creating an overlay over blkreplay
with explicit '-snapshot' option breaks the determinism.

v2 changes:
 - removed useless bdrv_ref/unref calls (as suggested by Kevin Wolf)
 - updated commit messages
 - minor changes

---

Pavel Dovgalyuk (3):
      block: implement bdrv_snapshot_goto for blkreplay
      blkreplay: create temporary overlay for underlaying devices
      replay: disable default snapshot for record/replay


 block/blkreplay.c |   73 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 stubs/replay.c    |    1 +
 vl.c              |   10 ++++++-
 3 files changed, 82 insertions(+), 2 deletions(-)

-- 
Pavel Dovgalyuk