Hi folks, Recently I learned how to configure libvirt with USB pass-though functionality. In my case I configured my guest domain with this block of code: <hostdev mode='subsystem' type='usb' managed='yes'> <source> <vendor id='0x0c93'/> <product id='0x1772'/> <address bus='1' device='4'/> </source> </hostdev> At first this worked fine, but then later the guest domain refused to start because the USB device was absent. When I checked, I found that its product ID had mysteriously changed to 1771. Later it was back at 1772. Now it appears that the USB device I am dealing with has a product ID that changes back and forth between 1771 and 1772 at random. Apparently, the Windows program running on the guest domain is designed to deal with this nonsense, but the question is, Can the guest domain be configured to deal with it? Something like <product id='0x177?'/> would be useful, but that doesn't work, nor does omitting the product tag. Any ideas would be much appreciated. Thanks, Jaap