[vfio-users] vga pass-thru and different gfx cards.

[Torbjorn Jansson]

On 2015-09-10 20:48, Alex Williamson wrote:
> Please reply-all, adding the list back.
>
oops.
got used to how some other mail lists work and didn't think to check.


> On Thu, Sep 10, 2015 at 12:44 PM, Torbjorn Jansson <
> torbjorn.jansson at mbox200.swipnet.se> wrote:
>
>> On 2015-09-10 19:47, Alex Williamson wrote:
>>
>>> On Thu, Sep 10, 2015 at 10:47 AM, Torbjorn Jansson <
>>> torbjorn.jansson at mbox200.swipnet.se> wrote:
>>>
>>> Hello all.
>>>>
>>>> first of all a big thanks to alex willamsons and his blog series about
>>>> getting a graphic card passed thru to a vm.
>>>> without those i wouldn't have been able to get it to work (more or less)
>>>>
>>>> first some hw info about my linux box where i'm using vfio & kvm:
>>>> asus p8Z77-v le with 16gb ram and at the moment i'm using a nvidia gt610
>>>> card from asus but i have also tried a gtx570.
>>>>
>>>> i got it to work after a bit of reading alex blogs and a lot of testing.
>>>> i use the built in intel gfx card for the host since that is no good for
>>>> anything else and the gt610 is passed thru to a win7 vm.
>>>>
>>>> first problem i have is that vga pass-thru only works one time after a
>>>> cold boot.
>>>> if i try to restart the vm or just power it of and on again i get a hard
>>>> lockup of the host.
>>>> this is the most annoying problem.
>>>>
>>>>
>>> It's not clear to me why there are numerous reports of reset problems on
>>> nvidia.  AFAIK, there's no broken hardware for nvidia in this space like
>>> there is for AMD.  So if you're having reset problems, maybe it's because
>>> you're not binding both GPU and audio functions to vfio-pci and therefore
>>> vfio-pci can't do a bus reset on VM reset.  Maybe your motherboard freaks
>>> out on the bus reset.  Maybe it's a ROM issue like Blank suggests.
>>>
>>>
>> both functions are bound to pci-stub via grub command line using:
>> pci-stub.ids=
>>
>> i forgot to say, i'm unfortunately stuck on linux kernel 4.0.4 due to
>> issues with drivers for a dvb card.
>> and my distro is fedora 22
>
>
> pci-stub is only to prevent host driver from binding to the device,
> eventually the device needs to get bound to vfio-pci or else you're not
> using vfio to do the assignment.

ok, and that gets taken care of by libvirt when i power up the vm?
i guess i have to check what driver is bound to the 2 functions once the 
vm is up and also check what happens once it is powered off.