Re: [Qemu-devel] What is the best commit for record-replay?

[Igor R]

>>>> I'm trying to use the deterministic record/replay feature, and I would
>>>> like to know which commit I should take to get it work.
>>>> In RC0 it seems to be broken. I tried pre-MTTCG commit 2421f381dc, as
>>
>>> Can you retry with the latest rc? There were some fixes regarding rr since 
>>> rc0.
>>
>>
>> I've taken 2.9 release, and RR does not seem to work there.
>> I recorded the boot process of x86 Fedora-21 linux and the replay got
>> stuck almost immediately.
>
> What's your command line?
>
> Does it get stuck at the same place each time?
>
> Can you boot fine with icount but without record/replay?

Here is the exact scenario:
- Get 2.9 from git, configure it as follows: "./configure
--target-list=i386-softmmu --enable-sdl" and  make.
- Download 
https://people.debian.org/~aurel32/qemu/i386/debian_squeeze_i386_standard.qcow2
- Run qemu with the following command line, until login prompt:
-icount shift=7,rr=record,rrfile=replay.bin -drive
file=debian_squeeze_i386_standard.qcow2,if=none,id=img-direct -drive
driver=blkreplay,if=none,image=img-direct,id=img-blkreplay -device
ide-hd,drive=img-blkreplay -monitor stdio
- Replay: -icount shift=7,rr=replay,rrfile=replay.bin -drive
file=debian_squeeze_i386_standard.qcow2,if=none,id=img-direct -drive
driver=blkreplay,if=none,image=img-direct,id=img-blkreplay -device
ide-hd,drive=img-blkreplay -monitor stdio

Every time I attempt to replay, QEMU gets stuck at the same EIP, at a
very early stage.


> Can you boot fine with icount but without record/replay?

Yes. I can also enable icount and recording - it also boots fine. The
problem with the replay.