Re: VT-D On An Asus P5E-VM DO Motherboard Not Working, Xen 3.4.1

[Christian Tramnitz <chris.ace@gmx.net>]

Michael MacLeod wrote:
> We have a bit of joy now folks. It appears to have been the Initiate 
> Graphics Adapter setting in the BIOS. It was set to use my PCIe graphics 
> card as the first option (which is the default value). I set it to use 
> integrated graphics (Intel 82Q35 Express) and now VT-d is enabled at 
> boot (even without Dexuan's patch). It's still a BIOS bug, as I believe 
> I should be able to use a PCIe graphics card and have VT-d work 
> correctly at the same time.
> 
> Unfortunately, 2.6.18.8-xen does not appear to have support for the 
> Intel graphics card that is the integrated graphics chip, so I lose my X 
> display. Oh, and when I try and actually launch a domU, I get this: 
> Error: pci: PCI Backend and pci-stub don't own device 0000:03:00.0. I 
> haven't had time to play with any of this yet though, so hopefully I can 
> surmount these obstacles as well.
> 
> Thanks everyone,
> Mike.


I could reproduce the error when completely disabling the IGD, but not 
by changing the init order.
I.e. I could successfully but with my Radeon as primary VGA device (with 
the IGD enabled but as secondary and unused device) and VT-d was still 
enabled.

This could be different when using PCIe because due to the limit of PCIe 
lanes the IGD might be disabled completely when using a PCIe video 
card... not sure about this though, so you may give it a try with IGD 
enabled but PEG/IGD init order.


Best regards,
    Christian