Thursday, August 30, 2012


Update 26/10/2012:
I've finally published my notes: HowTo: Xen 4.1.3 Windows 8 HVM domU with Intel HD4000 VGA Passthrough on Debian Wheezy

A month has passed since I got the new hardware and I have some novelties to share!

First I got XEN VGA Passthrough working and surprisingly it turned out to be quite easy to setup and I'm pretty happy with the results. I managed to passthrough the i7-3770 HD4000 integrated GPU, USB 2.0 Controller, HD Audio and secondary Ethernet to a Windows 8 Preview domU HVM on a Debian Wheezy dom0 using the xm toolstack. In the domU assigned USB controller I've connected an additional keyboard and mice.

As I only have the integrated GPU and no discrete graphics card I have to SSH from my laptop or use Putty from within Windows to control the dom0.

Now for the observations and quirks on Xen PCI Passthrough:
  • During Windows 8 installation some artefacts appear but these didn't prevent or difficulted the installation process.
  • Un-plugging and plugging the USB keyboard and mice didn't affect stability expect on one occasion where graphical artefacts appeared in Windows though I suspect this could be from the DQ77MK USB 2.0 "fast charge" ports. I have on my TODO list to passthrough another controller to double-check.
  • Windows 8 Preview complained twice about crashed video drivers but its stability wasn't affected and the OS automatically reloaded the driver. One of these situations occurred after I kicked the power connector where I have ~8 power cords connected (this was one of the 2 situations were visual artefacts appeared in Windows outside of the installation process).
  • Wolfenstein: Enemy Territory performance was crap having scored ~59 FPS in 5 timedemo runs. I have to further research the poor performance though I have a few suspects, however it could turn out to be something with the OS so I'll need to install Windows 8 on bare metal (brrr...) to compare.
  • I really need to run some benchmarks using common tool such as 3DMark and Phoronix Test Tool and compare the VM performance with bare metal.
  • My Windows 7 install media is corrupted so Windows 8 Preview ISO was used
  • Sound works perfectly.
  • The second Ethernet is running like a champ.
  • Boot speed is reasonnable especially taking account that the VM is stored in a 9 years-old HDD.
  •  Came across some Windows repair boot menus. Either I'm too trigger happy to kill the domU when I see "lengthily" boots or shutdown (from both domU or using xm destroy) or there really are some issues. Will have to look into this in the future.
  • I still have to passthrough another USB controller to test if USB pen and such are properly registered in the domU.
  • The dom0 stability was never affected.
  • Steam and its Source engine games work just fine having scored ~209FPS in Source stress test (dunno if this is good or bad has I don't have a bare metal comparison baseline).
  • I've clocked more than 5h on Team Fortress 2, Counter-Strike Source and Day of Defeat. No issues aside from being hooked on Team Fortress 2 -.-'
  • I'm impressed with Team Fortress 2 graphics, smooth performance and gameplay.
All in all I'm most pleased with Xen PCI Passthrough and I'll be writing an HOWTO on in the coming weeks.

There's still so much more to be explored but Team Fortress 2 is sucking my free time :(

1 comment:

  1. Hi Tangram,
    I have a similar setup but does not fully work.

    The host CPU is the same i7 3770, with a different board Asrock H77m-itx. The host SW setup is also debian Wheezy with stock xen 4.1.3. I've tried both the stock kernel and an 3.6.0 kernel in experimental. The guest I was trying is the openelec 2.0 -- an linux based distro for HTPC with kernel version 3.2.x I remember.

    The current status I got with the 3.6.0 kernel is like this: the domU boots fine no freeze, lock up etc. All the assigned devices (IGD, audio, usb) can be recognized and appears to be working from various logs (lsusb, lspci, aplay, Xorg.log, xrandr, vainfo, EDID report etc).

    However, I can't get any video output. The panel (VGA1) / TV (Hdmi3( keeps complaining about 'no signal' input. I haven't tried with a second guest to see if this issue is specific to this guest.

    I wounder if you could share some of your kernel / xen (better if you have a linux domU kernel log) logs for me to compare? The setup looks similar and should give me some hint.