Re: [Xen VGA Passthrough] Cannot Complete All 3dmark Tests in Windows 8 HVM domU

[Gordan Bobic <gordan@bobich.net>]

On 09/16/2014 11:50 PM, Zytaruk, Kelly wrote:
> Hi Gordan,
>
> Your request comes at a very opportune time.  I have just started looking into asic reset and FLR support.
> I found your thread at http://xen.1045712.n5.nabble.com/Re-VGA-passthrough-with-Xen-4-3-and-xl-toolstack-performance-degradation-resolved-td5721581.html
>
> I notice that there is mention of two patches; one for PCI bus reset and one for secondary passthru.  I have seen a couple very old patches for primary passthru but I haven't looked at these two yet.  If you could forward me a link to these patches I can quickly take a look and see whether it makes more sense to put a fix into QEMU or into the graphics driver.

I don't recall patches for secondary passthrough, but that thread was 
quite a few months ago so I could be wrong.

The device reset via bus reset was, IIRC, included in the upstream 
kernel a while back. See:
http://lwn.net/Articles/562212/

I don't know at what kernel version this functionality may have been 
included. I'd hazard a guess that anyone who has an ATI card surviving 
domU reboots consistently has this functionality in their kernel.

Gordan