Re: vga passthrough // questions about pci passthrough

[Martin Wolf <mwolf@adiumentum.com>]

well my first tests with the vga rom were useless because of apparmor 
rules i guess
now i placed the vga.rom in /usr/share/qemu ... well the error is gone 
now but no changes ;)
so i added the "bar" parameter but it also made no difference :(

are you interested in the windows memory dump from the bsod?

another thing, after i ran some benchmarks after a fresh reboot on win7 
i wanted to measure some
values of the 7870 so i started gpu-z ( http://www.techpowerup.com/gpuz/ )
then almost immediately the vm froze
i found one log entry in one of the libvirt log files:

kvm: /build/buildd/qemu-kvm-1.2.0+noroms/exec.c:2255: register_subpage: 
Assertion `existing->mr->subpage || existing->mr == &io_mem_unassigned' 
failed.
maybe you know what this is about.

thanks again for your patience and help ;)

Am 28.09.2012 10:12, schrieb Jan Kiszka:
> On 2012-09-27 21:18, Alex Williamson wrote:
>> On Thu, 2012-09-27 at 20:43 +0200, Martin Wolf wrote:
>>> thank you for the information.
>>>
>>> i will try what you mentioned...
>>> do you have some additional information about rebooting a VM with a
>>> passed through videocard?
>>> (amd / ati 7870)
>> I don't.  Is the bsod on reboot only or does it also happen on shutdown?
>> There's a slim chance it could be traced by enabling debug in the
>> pci-assign driver and analyzing what the guest driver is trying to do.
>> I'm hoping that q35 chipset support might resolve some issues with vga
>> assignment as it exposes a topology that looks a bit more like one that
>> a driver would expect on physical hardware.  Thanks,
>  From our attempts to get more working than what NVIDIA Quadro cards
> support officially, my own experiments with q35 in this context and our
> discussions with NVIDIA, I'm pretty skeptical that this chipset will
> make a difference here. Most problems are due to those non-standard side
> channels to configure the hardware, memory mappings etc. And getting
> this working requires either cooperation of the vendor or *a lot* of
> reverse engineering.
>
> Jan
>


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