Re: [Qemu-devel] winXP "Standard PC" HAL and qemu-kvm >= 0.15

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2011-12-06 19:13, Michael Tokarev wrote:
> On 06.12.2011 20:57, Michael Tokarev wrote:
>> On 06.12.2011 20:38, Jan Kiszka wrote:
>>> On 2011-12-06 17:29, Michael Tokarev wrote:
>> []
>>>> It appears there are two issues here, one is fixed by
>>>> 09de0f469c3c2a277c7874f6c60992c8b94719a9 and is 32bit-only, and
>>>> another bisect leads to this commit:
>>
>> Or 3... :)
>>
>>>> commit 59539c913383fdd3350681301b44f02fa7ee2757
>>>> Author: Jan Kiszka <jan.kiszka@siemens.com>
>>>> Date:   Mon Jun 27 12:22:28 2011 +0200
>>>>
>>>>     qemu-kvm: Fix in-kernel PIC reset
>>
>> []
>>>> Anything wrong with this patch?
>>>
>>> I tend to say "no". It may just reveals some issue elsewhere.
>>>
>>> To cross-check: Does this series [1] expose the same issue with vanilla
>>> QEMU when enabling that in-kernel irqchip version?
>>
>> I cross-checked it the other way, which really should have been done
>> at the very beginning instead of wasting so much time of so many
>> people at once.  I just tried qemu-kvm-1.0, which I wasn't due to
>> an unrelated issue (1.0 does not work for me in my funky 32/64bit
>> environment).  Also, since the bug has been reported especially
>> against 0.15 version (triggering by upgrading from 0.14 to 0.15),
>> I didn't insist on trying 1.0, which was my biggest mistake.
>>
>> And in qemu-kvm-1.0, the problem guest Just Works.  So i t must be
>> something else which were fixed between 0.15 and 1.0.
> 
> For the 0.15 .. 1.0 change, the first commit which restores the (broken
> in 0.15) functionality is this one:
> 
> commit 86fbf97ceb4a9c46a609dd4ae053ba4262b68fe8
> Author: Jan Kiszka <jan.kiszka@siemens.com>
> Date:   Fri Oct 7 09:19:45 2011 +0200
> 
>     i8259: Clear ELCR on reset
> 
>     The ELCR is actually part of the chipset but we model it here for
>     simplicity reasons. The PIIX3 clears the ELCR on reset, which was once
>     broken by 4dbe19e181. Fix this by splitting up pic_init_reset from
>     pic_reset and clearing the register in the latter.
> 
>     Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>     Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
> 
> Which is quite expected having in mind the commit which "broke"
> it for 0.15.

Yep, makes a lot of sense. That patch should be applied to stable then
(who's in charge?).

> 
>> Upstream qemu 1.0 does not have this issue too.
>>
>>> [1] http://thread.gmane.org/gmane.comp.emulators.kvm.devel/82871
>>
>> I'll try to verify this series in a moment, but hopefully it will work
>> fine too :)
> 
> And that turned out to be not so easy for me.  Which is this
> series against?  Is there may be a git tree with this series
> applied already?

Oops. It's against qemu-kvm's uq/master queue. Find a git tree at

git://git.kiszka.org/qemu-kvm.git queues/kvm-irqchip

Jan

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