[Xen-users] USB PCI Passthrough System Instability

["Mike Brotzman" <mbrotzman.jhu@xxxxxxxxx>]

I recently managed to get PCI Passthrough to work for a Windows HVM operating under Xen 3.2 on Fedora 8.  I needed to get USB ports passed through to the Windows VM with full hot plug functionality and I was able to get that working using a Dell 755 with a USB PCI expansion card.  However, when trying to bring the box up to an operational status status I have encountered some rather severe stability problems.  What happens is that about 5 minutes after first using the USB device (successfully without any issues), a subsequent insertion causes the Windows XP "System" process to instantly run away to 99% CPU usage, the USB device is not detected and the only fix is to reboot Dom0.  Shuting down the Windows VM has no effect and it goes back to spinning as soon as the System process is initialized during bootup.  Eventually repeted shuting down of the spinning VM results in a hard crash/immediate reboot of the host machine, no kernel panic or anything, just immediate reboot.  Once the host machine is rebooted (hard crash or not) the problem goes away temporarily, but returns 100% of the time.  I should also mention that when I create the Windows VM I get Xem errors complaining of recieving an NMI and I might have a hardware problem, but the VM starts anyway.  

I know that the PCI Passthrough system is not that robust and people have said that it makes Xen much less stable.  I was hoping that someone should let me know if there is any way to fix/mitigate my problem or if, at this time, there is nothing to be done.

Thanks in advance.
_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users