Re: RE: VT-d support proprietary NVidia/ATI GPU passthrough

[Weidong Han <weidong.han@intel.com>]

Konrad Rzeszutek Wilk wrote:
> On Mon, Feb 22, 2010 at 12:32:48PM +0000, Timothy J. Moore wrote:
>   
>> How can xen implement these vendor specific resets?  How could we find out the gfx vendor specific stuff?
>>
>> Can we take anything from the opensource NV, nouveau, or Gallium3D drivers?
>>     
>
> As I understand it, the reason for the FLR is to re-initialize the video
> cards to re-run through the basic ROM code. Pretty much exactly the same
> thing that is done during machine startup. But for gfx pass-through you
> need to this with the Bochs code running so it can call the gfx BIOS.
>
> I don't think that the open-source drivers go so low to re-initialize
> the card?
>
> Thought perhaps another way to do this, is to put the cards in D3 (cold)
> state and then re-initialize them back up? (this is btw, what the
> pciback drivers does when it seizes the card).
>   
reset through Dstate transition is not guarantee to work for all 
devices. As we observed, it seems didn't work for Intel IGD, so we 
implemented vendor specific reset for Intel IGD.

Regards,
Weidong