[vfio-users] VM doesn't boot if I use GPU passthrough

[Frederick N. Brier]

I had a similar error code 43 at one point.  I had forgotten to remove 
the Cirrus video from the configuration.  That fixed it.  So with the 
PCI Passthrough, there were two.  The driver properties error code was 
2B.  If you are connecting with TightVNC, you could also be seeing two 
VGA video cards in Device Manager with one of them having the yellow 
exclamation point, the other fine.

On 01/28/2016 04:56 PM, Nicolas Roy-Renaud wrote:
> Ok, try to remove your passthrough from your guest configuration 
> (either using virsh of virt manager). That is : remove the actual gpu 
> (PCI:1:0.0) but keep the associated sound card (PCI:1:0.1) in there so 
> virsh knows it needs to bind with this VFIO group.
> From there, create a file (let's say ./GPU_DEVICE.xml) containing just 
> the following :
>
>     1.
>         <hostdevmode='subsystem'type='pci'managed='yes'>
>     2.
>         <source>
>     3.
>         <addressdomain='0x0000'bus='0x01'slot='0x00'function='0x0'/>
>     4.
>         </source>
>     5.
>         <addresstype='pci'domain='0x0000'bus='0x00'slot='0x02'function='0x0'/>
>     6.
>         </hostdev>
>
>
> You'll be able to use this file to tell libvirt to append your GPU to 
> guest's config at runtime, which somehow gets around the invalid ROM 
> issue. Just run something like this :
> virsh start Win10Full && sleep 60 && virsh attach-device --live --file ./GPU_DEVICE.xml
> If I guessed right, windows should detect a new GPU and get the 
> drivers in place once virsh is done mounting it. If that does work, 
> you'll gave to run this same command every time you start your VM too, 
> or at least until that specific bug is fixed. Hopefully that should 
> get you some results so you can work your way from there.
>
> On 2016-01-28 17:03, Ryan Flagler wrote:
>> I was going to recommend you use UEFI, which is why I was asking. 
>> I've personally had better luck getting things to pass through properly.
>>
>> Is your VM down when you try to cat the rom? The GPU needs to be 
>> unused by anything.
>>
> I had the exact same symptoms on my Asus Strix 970, looks like a 
> recurring issue with Asus cards. This happenned both when trying to 
> start a VM with a managed passthrough and when attempting to dump the 
> ROM from sysfs. I figured it's probably an issue with vfio-pci itself, 
> and I still haven't fixed it wet, but the solution I posted above is 
> my current workaround.
>
>
> _______________________________________________
> vfio-users mailing list
> vfio-users at redhat.com
> https://www.redhat.com/mailman/listinfo/vfio-users

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/vfio-users/attachments/20160128/1ba3e9bd/attachment.htm>