libvirt users - Mar 2012 - Constantly changing USB product ID

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

Quoting Jaap Winius <jwinius at umrk.nl>:
> ... Something like <product id='0x177?'/> would be useful,
but that
> doesn't work, nor does omitting the product tag.
Another useful solution (certainly for me) would be the ability to  
pass-through any USB device that is attached to a certain physical  
bus/device number to the guest domain. But, I don't know that this is  
possible either.

Anyone?

Thanks

Jaap