I am attempting to install mythtv backen on virtual system. I assigned raid controler sound card and pci tv capture card without any issues. I assigned 3.0 usb controler and few of onboard controlers blacklisted usb modules but usbcore still gets loaded on boot in domu. I had pluged in hauppauge usb silicon dusts based tv tunner and proper modules are loaded and network is created with proper ip address. mythtv recognizes the tunners in setup but when I start backend it claims it can''t connect to the tunners it seems that xen is blocking communication between usb port and device.