[panda-users] Replay Failing

Mon Jul 10 21:57:59 EDT 2017

I actually checked yesterday and the bug is still present in the newest
version of QEMU. It may be worth filing a bug report with them.

On Mon, Jul 10, 2017 at 9:56 PM Danux <danuxx at gmail.com> wrote:

> You were right Brendan, the loadvm command failed with same error, but I
> installed Qemu through Panda installation script, I assumed it uses a
> working version.
>
> Can I upgrade Qemu to latest version separetely, or I need to compile Qemu
> from scratch with Panda libraries?
>
> Thanks.
>
> On Sat, Jul 8, 2017 at 6:23 PM, Brendan Dolan-Gavitt <brendandg at nyu.edu>
> wrote:
>
>> It looks like the vexpress-a9 machine doesn't have a PCI bus, so you
>> can't use IDE or SATA devices. However, if you need big endian I think
>> you're out of luck anyway – I believe the vexpress-a9 board is also little
>> endian. QEMU does support big endian arm, but I think it doesn't model any
>> boards that use big-endian by default:
>>
>>
>> https://stackoverflow.com/questions/41571643/emulatin-big-endian-arm-system-with-qemu
>>
>> (That answer is from one of the QEMU developers. Things may have changed
>> since 2011 though.)
>>
>> Moving this back to the mailing list so that other people can benefit...
>>
>> -Brendan
>>
>> On Sat, Jul 8, 2017 at 9:02 PM, Danux <danuxx at gmail.com> wrote:
>>
>>> Hi Brendan,
>>>
>>> Thanks a lot for your help.
>>> Happy to get in touch with you, really like Panda concept so hope to get
>>> this solved.
>>>
>>> Is there a way to use ide or something else instead of sd? I used -sd
>>> option just because I followed a blog.
>>>
>>> I need ARM big endian,  little endian does not help me.
>>>
>>> Will try all those suggestions and come back here with my feedback.
>>>
>>> On Jul 8, 2017 7:37 PM, "Brendan Dolan-Gavitt" <brendandg at nyu.edu>
>>> wrote:
>>>
>>> The ARM issue seems to be a bug in QEMU. Replaying a recording requires
>>> loading a saved snapshot, and it appears that the SD card device in QEMU
>>> isn't properly loading the snapshot (you can verify this by trying to take
>>> a snapshot with savevm and loading it with loadvm afterward). One
>>> workaround would be to use the "armel" image instead, which does not use an
>>> SD card.
>>>
>>> As for the WinXP example, it's harder to tell what could be going wrong.
>>> Are you able to do a successful recording using the i386 Linux image? (You
>>> can test with panda/scripts/run_on_32bit_linux.py – it will download an
>>> appropriate QCOW and run a command in a 32-bit x86 Debian image for you).
>>>
>>> Also, note that you should not need to use sudo to run PANDA (and it's
>>> not recommended).
>>>
>>> Finally, I noticed you stopped by on IRC – unfortunately we can't be on
>>> there 24 hours a day, so you may need to hang around a while before someone
>>> can respond to your question. A persistent IRC client (e.g., irssi running
>>> in a screen session) can help with this.
>>>
>>> On Sat, Jul 8, 2017 at 3:59 AM, Danux <danuxx at gmail.com> wrote:
>>>
>>>> Here is another try but now with WinXP, it is also failing :-(
>>>>
>>>> Running on:
>>>>
>>>> Linux panda 4.4.0-83-generic #106~14.04.1-Ubuntu SMP Mon Jun 26
>>>> 18:10:19 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
>>>>
>>>> danux at panda:~/panda/build/i386-softmmu$ sudo ./qemu-system-i386 -drive
>>>> file=/media/drive/winXP.qcow2,if=ide,cache=writeback -m 1024M --monitor
>>>> stdio -vnc 192.168.1.74:1 -replay notepad
>>>>
>>>> [sudo] password for danux:
>>>>
>>>> QEMU 2.8.50 monitor - type 'help' for more information
>>>>
>>>> (qemu) loading snapshot
>>>>
>>>> ... done.
>>>>
>>>> opening nondet log for read : ./notepad-rr-nondet.log
>>>>
>>>> Ahead of log while looking for log entry of type RR_SKIPPED_CALL
>>>>
>>>> {guest_instr_count=7526}
>>>>
>>>> RR_INPUT_4 from RR_CALLSITE_READ_4
>>>>
>>>> FOUND DISAGREEMENT!
>>>>
>>>> Replay program point:
>>>>
>>>> {guest_instr_count=7528}
>>>>
>>>>
>>>> Record program point:
>>>>
>>>> {guest_instr_count=7526}
>>>>
>>>>
>>>> >>> guest instruction counts disagree
>>>>
>>>> notepad:        7528 (  0.00%) instrs.    0.09 sec.  0.30 GB ram.
>>>>
>>>> ERROR: replay failed!
>>>>
>>>> Time taken was: 0 seconds.
>>>>
>>>> Stats:
>>>>
>>>> RR_INPUT_1 number = 0, size = 0 bytes
>>>>
>>>> RR_INPUT_2 number = 0, size = 0 bytes
>>>>
>>>> RR_INPUT_4 number = 22, size = 308 bytes
>>>>
>>>> RR_INPUT_8 number = 25, size = 450 bytes
>>>>
>>>> RR_INTERRUPT_REQUEST number = 11, size = 154 bytes
>>>>
>>>> RR_EXIT_REQUEST number = 0, size = 0 bytes
>>>>
>>>> RR_SKIPPED_CALL number = 0, size = 0 bytes
>>>>
>>>> max_queue_len = 13
>>>>
>>>> ERROR: replay failed!
>>>>
>>>> On Fri, Jul 7, 2017 at 10:42 PM, Danux <danuxx at gmail.com> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> When trying to run the replay option on a linux ARM system is failing
>>>>> as follows, please help:
>>>>>
>>>>> (qemu) begin_record test
>>>>>
>>>>> (qemu) writing snapshot: ./test-rr-snp
>>>>>
>>>>> opening nondet log for write : ./test-rr-nondet.log
>>>>>
>>>>> (qemu) end_record
>>>>>
>>>>> (qemu) Time taken was: 75 seconds.
>>>>>
>>>>> (qemu) begin_replay test
>>>>>
>>>>> (qemu) loading snapshot
>>>>>
>>>>> qemu-system-arm: /home/danux/panda/hw/sd/sd.c:217: sd_ocr_powerup:
>>>>> Assertion `!(sd->ocr & 0x80000000)' failed.
>>>>>
>>>>> Or by passing the replay in the command line:
>>>>>
>>>>>
>>>>> danux at panda:~/panda/build/arm-softmmu$ ./qemu-system-arm  -M
>>>>> vexpress-a9 -sd snapshot.img -kernel vmlinuz-3.2.0-4-vexpress -initrd
>>>>> initrd.img-3.2.0-4-vexpress  -replay test -m 256M
>>>>>
>>>>> audio: Could not init `oss' audio driver
>>>>>
>>>>> loading snapshot
>>>>>
>>>>> qemu-system-arm: Missing section footer for sd-card
>>>>>
>>>>> Failed to load vmstate
>>>>>
>>>>> Failed to start replay
>>>>>
>>>>>
>>>>> Please help me
>>>>>
>>>>>
>>>>> Thanks!
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> DanUx
>>>>
>>>> _______________________________________________
>>>> panda-users mailing list
>>>> panda-users at mit.edu
>>>> http://mailman.mit.edu/mailman/listinfo/panda-users
>>>>
>>>>
>>>
>>>
>>> --
>>> Brendan Dolan-Gavitt
>>> Assistant Professor, Department of Computer Science and Engineering
>>> NYU Tandon School of Engineering
>>>
>>>
>>>
>>
>>
>> --
>> Brendan Dolan-Gavitt
>> Assistant Professor, Department of Computer Science and Engineering
>> NYU Tandon School of Engineering
>>
>
>
>
> --
> DanUx
>
-- 
Brendan Dolan-Gavitt
Assistant Professor, Department of Computer Science and Engineering
NYU Tandon School of Engineering
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