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

[Aleksandr Bezzubikov]

[+CC Pavel Dovgaluk, me]

2017-09-18 15:02 GMT+03:00 Aleksandr Bezzubikov <address@hidden>:
> 2017-05-02 15:42 GMT+03:00 Igor R <address@hidden>:
>>>>>> 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.
>
> Hi guys,
> Maybe the thread is a bit outdated, but the problem is still relevant.
> I've just tried to record and replay WinXP boot process, and I've encountered
> exactly the same problem as described above - record is fine, replay
> gets stuck early. I use current master.
> And I've discovered the second problem - recording makes initial snapshot,
> but it doesn't seem to be saved to the disk - replay can't see it.
>
> Hope you've already found the solution (as the last post was on 2 May)
> and it's just got missed the mailing list.
>
>>
>
>
>
> --
> Aleksandr Bezzubikov



-- 
Aleksandr Bezzubikov