Re: [Qemu-devel] [for-4.2 PATCH 3/6] replay: update docs for record/replay with block devices

[Kevin Wolf <kwolf@redhat.com>]

Am 17.09.2019 um 13:58 hat Pavel Dovgalyuk geschrieben:
> From: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
> 
> This patch updates the description of the command lines for using
> record/replay with attached block devices.
> 
> Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
> ---
>  docs/replay.txt |   12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/docs/replay.txt b/docs/replay.txt
> index ee6aee9861..ce97c3f72f 100644
> --- a/docs/replay.txt
> +++ b/docs/replay.txt
> @@ -27,7 +27,7 @@ Usage of the record/replay:
>   * First, record the execution with the following command line:
>      qemu-system-i386 \
>       -icount shift=7,rr=record,rrfile=replay.bin \
> -     -drive file=disk.qcow2,if=none,id=img-direct \
> +     -drive file=disk.qcow2,if=none,snapshot,id=img-direct \
>       -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay \
>       -device ide-hd,drive=img-blkreplay \
>       -netdev user,id=net1 -device rtl8139,netdev=net1 \
> @@ -35,7 +35,7 @@ Usage of the record/replay:
>   * After recording, you can replay it by using another command line:
>      qemu-system-i386 \
>       -icount shift=7,rr=replay,rrfile=replay.bin \
> -     -drive file=disk.qcow2,if=none,id=img-direct \
> +     -drive file=disk.qcow2,if=none,snapshot,id=img-direct \
>       -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay \
>       -device ide-hd,drive=img-blkreplay \
>       -netdev user,id=net1 -device rtl8139,netdev=net1 \
> @@ -223,7 +223,7 @@ Block devices record/replay module intercepts 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.qcow2,if=none,id=img-direct
> + -drive file=disk.qcow2,if=none,snapshot,id=img-direct
>   -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay
>   -device ide-hd,drive=img-blkreplay
>  
> @@ -252,6 +252,12 @@ This snapshot is created at start of recording and restored at start
>  of replaying. It also can be loaded while replaying to roll back
>  the execution.
>  
> +'snapshot' flag of the disk image must be removed to save the snapshots
> +in the overlay (or original image) instead of using the temporary overlay.
> + -drive file=disk.ovl,if=none,id=img-direct
> + -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay
> + -device ide-hd,drive=img-blkreplay

Wait, didn't patch 2 just make -snapshot unconditionally incompatible
with replay? So isn't saving the snapshot in the original image the only
supported mode now?

Kevin