Thursday, September 10, 2009

The Final Solution: PCI Express x16 Graphics Card Passthrough to Windows XP Home Edition 32-bit HVM Virtual Machine

Here is my latest video presentation on VGA passthrough. Please check out the Youtube link at

The "not enough free resources" issue for nVidia Geforce 8400 GS PCI Express x16 graphics card in earlier presentation videos:

has been fixed. Device manager in Windows XP HVM domU no longer shows an exclamation mark besides the nVidia Geforce 8400 GS graphics card. The device is working properly and the resources tab shows the available memory ranges.

Full VGA passthrough to Windows XP HVM guest operating system using Xen virtualization has been achieved. I am now able to run 3-D video benchmarks on the passed through nVidia GeForce 8400 GS graphics card.

All this is possible using Xen 3.5 hypervisor with Intel supplied VGA passthrough patches. Instead of using pvops dom0 kernel 2.6.31-rc6 which causes Win XP domU to run slowly, I am now using pvops dom0 kernel 2.6.30-rc3.

I am now able to bootstrap Windows XP HVM domU from within Linux using Xen virtualization and play 3D games in the Windows virtual machine. In the past, Windows virtual machines can only access a 2D emulated/virtual display adapter. The virtualized Windows operating systems were more palatable to server administrators than gamers. With VGA pass through and direct hardware access by Windows virtual machines to the graphics hardware, gamers will now be able to play 3D games inside Windows virtual machines.

There is still one unresolved problem. I am still unable to passthrough USB devices, e.g. keyboard and mouse, to the Windows XP HVM domU.

Special thanks to the following people who have helped me along the way. Without their guidance I would not have made it this far.

(1) Boris Derzhavets
(2) Pasi Kärkkäinen
(3) Han Weidong, Intel Corporation
(4) Doug Magee
(5) Timothy Moore
(6) Christian Tramnitz

and many other people from the xen-devel mailing list.


[1] Direct Access to Graphics Card Leveraging VT-d Technical Report; Beng Heng Ng, Billy Lau and Atul Prakash; July 20, 2009; University of Michigan


[2] VGA passthrough in Xen; Y. Schaeffer; University of Amsterdam


[3] Xen VGA passthrough; Yuri Schae er BSc; University of Amsterdam