I was reading the Wiki page here: http://wiki.xen.org/wiki/VTd_HowTo don't know how updated it is, BUT at the top it said: -------------------- -------------------- -------------------- -------------------- -------------------- -------------------- _Xen 4.1 xl tools notes _ * Only devices with FLR capabilities are supported. * Passing through a PCI card without FLR capability will result an error. To check if your PCI devices have FLR function, check in this wiki, [How can I check if PCI device supports FLR (Function Level Reset) ? ] If you see output with "FLReset-" then your PCI device don't support FLR function. If output have "FLReset+" then it does. As this time of writing, June 2012, there are very very few PCI devices support FLR function. -------------------- -------------------- -------------------- -------------------- -------------------- -------------------- THAN was reading here: http://wiki.xen.org/wiki/Xen_PCI_Passthrough#How_can_I_check_if_PCI_device_supports_FLR_.28Function_Level_Reset.29_.3F at the bottom of the page where it says: -------------------- -------------------- -------------------- -------------------- -------------------- -------------------- _How can I check if PCI device supports FLR (Function Level Reset)? _ Run "lspci -vv" (in dom0) and check if the device has "FLReset+" in the DevCap field. If you are Ubuntu/Debian user don't forget to add sudo at front, otherwise, you won't get the result you should get. sudo lspci -vv | egrep -i --colour flreset The above line should get root access for lspci program and show colour with flreset it found from output -------------------- -------------------- -------------------- -------------------- -------------------- -------------------- I did that and ALL of my devices it listed showed "FLReset-", there were only 3x "Etron Technology, Inc. EJ168 USB3.0" controllers that showed "FLReset+" SO, I have been trying to get my ATI FirePro V7900 Video Card to passthru to a Windows 7 Ultimate DomU with no luck so far AND was wondering how critical was for that device to show as "FLReset+"? 1.) Since my VGA card and AUDIO component of it, shows up as "FLReset-", does that mean it is impossible to get it fully working in a Win7 DomU? 2.) Does having the feature "FLReset+" depend on the motherboard BIOS, motherboard hardware or the BIOS onboard the Video Card that could be updated to get back the "FLReset+" so you can have the FLR reset functionality? I just spent a lot of time and money building this computer for the purpose of getting Xen to work (So far still working on that), i would just hate to see all of that go to waste, SO hoping someone could answer the above concerns... :) Thank you as always