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

[Michael Tokarev <mjt@tls.msk.ru>]

On 06.12.2011 16:27, Michael S. Tsirkin wrote:
> On Tue, Dec 06, 2011 at 03:02:49PM +0400, Michael Tokarev wrote:
[]
>> And after applying Avi's instructions here's the real bisect
>> result:
>>
>> ab431c283e7055bcd6fb622f212bb29e84a6a134 is the first bad commit
>> commit ab431c283e7055bcd6fb622f212bb29e84a6a134
>> Author: Isaku Yamahata <yamahata@valinux.co.jp>
>> Date:   Fri Apr 1 20:43:23 2011 +0900
>>
>>     piix_pci: optimize set irq path
> 
> Could you try with this commit reverted please?
> Reverting patch below. Warning: compiled only.

After some discussion on IRC, here's a summary.

I applied this patch on top of qemu-kvm-0.15.0.
The resulting executable shows the same bad behavour with my
test guest as it was without this patch.  So apparently just
reverting this patch isn't enough for the problem to go away.

But when doing a bisection, the result is very reliable - it
always points to the commit above (which we tried to revert
by this patch).

More data points (all against qemu-kvm-0.15.0).

First, as Avi pointed out, this patch references PIC which is
used by standardPC HAL and not used by ACPI HAL.  So it might
be something to think about, at least.

Now, so far, all deviecs which are on IRQ11 are affected.  When
enabling USB and NIC, they both gets assigned to IRQ11 and both
does not work.  When enabling just one of them (either), only
that device (which gets assigned to IRQ11) does not work.  All
other devices apparently works fine (including PS/2 Mouse on
IRQ12).

When using just one of NIC/USB, all IRQs in the guest becomes
single-device, so IRQ sharing isn't a problem.

I wasn't able to force the guest to use IRQ10 so far (to verify).

Also, when booted with -no-kvm-irqchip, guest Just Works, including
USB and NIC sharing IRQ11.

While on IRC there was one more person who suffered from the same
issue, now with Win2003.  He was able to solve his guest issue by
changing StandardPC HAL into ACPI HAL, using a "hackish" way (by
replacing C:\Windows\System32\HAL.DLL into HALACPI.DLL as found
on win2k3 installation CDROM).  I wasn't able to replace stdhal
into anything else on my test winXP machine - after changing HAL.DLL,
on next reboot my guest complains about being unable to find boot
device (BSOD STOP 0x7b) - despite using stdIDE and mergeide.  I'll
investigate the guest side further later.

When in this funky mode with non-working IRQ11 (when a NIC (rtl8139)
is assigned to it), winXP guest shows huge delays when trying to
open "My Computer" properties - it freezes for 30..40 seconds after
hitting "Properties" in the context menu.  I can only guess it is
trying to do something with the IRQs at that time, which does not
work.  I wasn't able to (quickly) find a tool for winXP to show
IRQ statistics.

That's about all the info so far which I know about this issue.

Thanks,

/mjt