Re: [Qemu-devel] Bug report - Windows XP guest failure

[Paolo Bonzini]

On 12/05/2015 09:22, Michael Tokarev wrote:
> 12.05.2015 04:05, Peter Crosthwaite wrote:
>> On Thu, May 7, 2015 at 2:34 AM, Michael Tokarev <address@hidden> wrote:
> ...
>>>> Ok, I can reproduce this, winXP BSODs on boot in tcg mode.
>>>> Git bisect points to this:
>>>>
>>>> commit 23820dbfc79d1c9dce090b4c555994f2bb6a69b3
>>>> Author: Peter Crosthwaite <address@hidden>
>>>> Date:   Mon Mar 16 22:35:54 2015 -0700
>>>>
>>>>     exec: Respect as_translate_internal length clamp
>>>
>>> This winXP BSOD happens on x86_64 target too.  Reverting the
>>> above commit from git master fixes the BSOD.
>>
>> Any useful info about IO addresses on that BSOD? The last issue with
>> this patch was IOPort code relying on the bug that this patch fixed.
>> This could be similar and if we can track the failure to a particular
>> address we can fix properly rather than another revert of that patch.
> 
> Oh.  I didn't know this patch has been reverted before.  Anyway, I disabled
> auto-reboot on BSOD on my winXP (what a "useful" feature!) and here's what
> I see.
> 
>   IRQ_NOT_LESS_OR_EQUAL
>   STOP: 0x0A (0x16, 0x02, 0x00, 0x80500EFC)
> 
> (with some amount of leading zeros stripped).
> 
> When this happens, win does something for quite some time, the BSOD comes
> after quite significant delay.
> 
> Is there anything else I can look at, maybe some crash dump or something?
> I haven't done any windows debugging before.

I would just put a breakpoint on the new condition introduced by the
commit, and see what causes the breakage.

Paolo