[fedora-virt] Issues with VGA passthrough using KVM and VFIO

[Stewart Adam]

On 2013-12-19 10:19 AM, Alex Williamson wrote:
> On Thu, 2013-12-19 at 01:48 -0500, Stewart Adam wrote:
>> Hi,
>>
>> I am trying to get VGA passthrough working using KVM and VFIO like
>> described on this [1] thread and ran into some issues I was hoping
>> someone could shed some light on. I have tried various configurations,
>> but can't seem to get it working correctly. Either I get "Code 10"
>> device error in Windows, or I get a BSOD 0x00000116 (VIDEO_TDR_ ERROR:
>> attempt to reset the display driver and recover from a timeout failed)
>> when booting the machine after installing the Catalyst 3D drivers.
>> Other users on the Arch Linux forum have also reported similar issues.
>>
>> <cut>
>
> Hi Stewart,
>
> The "x" in the x-vga option is for eXperimental.  It works in some
> cases, not others.  The archlinux forum thread is the best place to
> either get help or commiserate with others having the same problem.  The
> advice there is largely not distribution specific.  The 0x116 BSOD is a
> common problem with assigned Radeon graphics, we don't have a solution
> yet.  Also note that this work is still under development, for the
> current "state of the art" you need a 3.13-rc kernel and qemu.git, and
> you may need to patch in some Intel graphics fixes for VGA arbitration.
> Even then, I have no reason to suspect the 0x116 BSOD is fixed.  More
> users seem to be having success with Nvidia cards, so if that's an
> option for you, it may be the quickest path to results.  Thanks,
>
> Alex

Hi Alex,

Thanks for replying so quickly. Ironically, I normally buy nVidia and 
purchased this Radeon card because I had read online they tend to do 
passthrough better (with Xen at least)... I didn't have much luck when I 
tried a Xen VM either though. I do have an nVidia card handy and will try 
that later tonight.

Would the VGA arbitration patches relate to the Code 10 errors? Also, I will 
try again with 3.13-rc later this week but should I use qemu-vfio.git or 
qemu.git?

I realize this is all bleeding edge and thank you for all of your work on 
it. Is there anything I can do to help you debug the 0x116 problem?

Lastly, out of curiosity - is the 0x116 error dependent on particular piece 
of hardware or it's a problem with the emulation layer + certain GPUs?

Regards,
Stewart