Re: Nvidia, Xen, and Vt-d

[Michael J Coss <mjcoss@alcatel-lucent.com>]

Tim Moore wrote:
> Hi Michael,
>
> I have found that the lspci output changes once you have successfully loaded a driver against it.
>
> In both cases, when used by pci-stub/pciback in DomU or starting X on Dom0 will make the NV card appear differently in the lspci output. 
>
> I would try and use the 2.6.18 kernel with the shipped "nv" X driver - I have found this combination to be the most compatible. In the xen-unstable tree, run "make linux-2.6-xen0-build" (from memory).
>
> So far I have only had success with passing through the Primary display adapter, I can`t get my secondary to work.. (I dont think it`s anything to do with the models of card, more that the secondary passthru doesnt work..)
>
> My Pri = GTX260 (512mb+sharedmem=864mb)
> Sec: 9500 GT (512mb)
>
> The main complication and issue that needs to be overcome is the support for FLR. Without this PCIe capability, the GPU cannot be reset after the DomU has initialised it. I have to perform a hard-reset of Dom0 for GPU Passthrough to work a second time.
>
> Tim
>   
Just as a follow up to this.  I decided before I go back to 2.6.18, to 
try the open source "nv" driver instead of the proprietary ones.  It 
started up the Xserver just fine, although performance for glxgears 
dropped through the floor.  <100 fps on a GTX 295 with an i7 3.3Ghz 
processor ouch.  Thanks for all the suggestions.

I'm going to try working with Nvidia to see if I can get them to help 
identify the problem, but I don't expect to get very far with that.  
Clearly, there is a problem with how they are accessing the card.

---Michael J Coss