[Qemu-devel] [PATCH v3 0/5] Deterministic replay extensions

[Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>]

This set of patches is related to the reverse execution and deterministic 
replay of qemu execution. It includes recording and replaying of serial devices
and block devices operations.

With these patches one can record and deterministically replay behavior
of the system with connected disk drives and serial communication ports
(e.g., telnet terminal).

Patches for deterministic replay of the block devices intercept calls of
bdrv coroutine functions at the top of block drivers stack.
To record and replay block operations the drive must be configured
as following:
 -drive file=disk.qcow,if=none,id=img-direct
 -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay
 -device ide-hd,drive=img-blkreplay

blkreplay driver should be inserted between disk image and virtual driver
controller. Therefore all disk requests may be recorded and replayed.

v3 changes:
 - introduced bdrv_flush callback for block drivers
 - introduced block driver for recording block operations (as suggested by Kevin Wolf)
 - added documentation for block record/replay

v2 changes:
 - removed obsolete call of qemu_clock_warp
 - fixed record/replay of aio_cancel
 - simplified call sequence for blk_aio_ functions in non-replay mode (as suggested by Kevin Wolf)

---

Pavel Dovgalyuk (5):
      replay: character devices
      icount: remove obsolete warp call
      replay: introduce new checkpoint for icount warp
      block: add flush callback
      replay: introduce block devices record/replay


 block/Makefile.objs       |    2 -
 block/blkreplay.c         |  156 +++++++++++++++++++++++++++++++++++++++++++++
 block/io.c                |    6 ++
 cpus.c                    |   10 +--
 docs/replay.txt           |   20 ++++++
 gdbstub.c                 |    2 -
 include/block/block_int.h |    7 ++
 include/qemu/timer.h      |    3 +
 include/sysemu/char.h     |   26 ++++++++
 include/sysemu/replay.h   |   15 ++++
 main-loop.c               |    2 -
 qemu-char.c               |   56 ++++++++++++++--
 qemu-timer.c              |    2 -
 replay/Makefile.objs      |    1 
 replay/replay-char.c      |   97 ++++++++++++++++++++++++++++
 replay/replay-events.c    |   41 ++++++++++--
 replay/replay-internal.h  |   16 +++++
 replay/replay.c           |   25 +++++++
 stubs/clock-warp.c        |    2 -
 stubs/replay.c            |    4 +
 20 files changed, 469 insertions(+), 24 deletions(-)
 create mode 100755 block/blkreplay.c
 create mode 100755 replay/replay-char.c

-- 
Pavel Dovgalyuk