[libvirt-users] usb passtrough stuck to a given

[Cole Robinson]

On 09/24/2014 04:11 PM, Mauricio Tavares wrote:
>       So I have an entry for a USB device ( ID 051d:0002, UPS) I want
> to use with a given vm client. In that vm client's config file I added
> something like this:
> 
>     <hostdev mode='subsystem' type='usb' managed='yes'>
>       <source>
>         <vendor id='0x051d'/>
>         <product id='0x0002'/>
>       </source>
>     </hostdev>
> 
> And that worked fine for a while. Now I moved the vm host, and then
> put the cable to the UPS on an available USB port
> 
> Bus 002 Device 006: ID 051d:0002 American Power Conversion Uninterruptible Power
> 
> and tried to restart the client... and got the following message:
> 
> error: internal error Did not find USB device 51d:2 bus:2 device:3
> 
> Er, why should it care about which bus and device this is? I thought
> my config would mean it would look for the device that matched the ID
> in the config no matter where it was. How did it learn and memorized
> what I guess is the old location?
> 

It needs to lookup the bus/device at VM startup time, so it can set
permissions on the device node.

Check your VM XML (not from /etc/libvirt, but from virsh dumpxml $vmname), and
ensure that the bus/device didn't get encoded somehow.

- Cole