Constantly changing USB product ID

Constantly changing USB product ID

[Jaap Winius]

Hi folks,

Recently I learned how to configure KVM 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 KVM be  
configured to deal with it? Something like <product id='0x177*'/>  
would be useful, but that doesn't work.

Any ideas would be much appreciated.

Thanks,

Jaap

Re: Constantly changing USB product ID

[Avi Kivity]

On 03/27/2012 05:48 PM, Jaap Winius wrote:
> Hi folks,
>
> Recently I learned how to configure KVM 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 KVM be
> configured to deal with it? Something like <product id='0x177*'/>
> would be useful, but that doesn't work.
>
> Any ideas would be much appreciated.
>

This is really strange.  What kind of device is this?

I've filed an RFE [1] for virt-manager for assigning USB host devices
opportunistically, that is if they're plugged they're assigned, and if
not the guest starts without them.  If it were implemented, you could
assign both 0x1771 and 0x1772 and whichever ID the device is today would
get assigned.


[1] https://bugzilla.redhat.com/show_bug.cgi?id=804432

-- 
error compiling committee.c: too many arguments to function

Re: Constantly changing USB product ID

[Avi Kivity]

On 03/28/2012 02:41 PM, Avi Kivity wrote:
> On 03/27/2012 05:48 PM, Jaap Winius wrote:
> > Hi folks,
> >
> > Recently I learned how to configure KVM 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 KVM be
> > configured to deal with it? Something like <product id='0x177*'/>
> > would be useful, but that doesn't work.
> >
> > Any ideas would be much appreciated.
> >
>
> This is really strange.  What kind of device is this?
>
> I've filed an RFE [1] for virt-manager for assigning USB host devices
> opportunistically, that is if they're plugged they're assigned, and if
> not the guest starts without them.  If it were implemented, you could
> assign both 0x1771 and 0x1772 and whichever ID the device is today would
> get assigned.
>
>
> [1] https://bugzilla.redhat.com/show_bug.cgi?id=804432
>

btw, the correct place for this discussion is likely the libvirt mailing
list, or maybe the virt-manager list if it exists.

-- 
error compiling committee.c: too many arguments to function

Re: Constantly changing USB product ID

[Gerd Hoffmann]

On 03/27/12 17:48, Jaap Winius wrote:
> Hi folks,
> 
> Recently I learned how to configure KVM 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.

Not sure what libvirt does there, but qemu can handle this just fine.
If you add '-device usb-host,vendorid=0x0c93,productid=0x1772' qemu will
start just fine no matter if the device is present or not.  You can plug
in in and out as you like and it will show up in the guest when plugged in.

Might be a some security thing, when running qemu depriviledged and
selinux-controlled libvirt probably has to make sure the files in
/dev/bus/usb/ have correct permissions and labels.

> 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.

Guess it has two modes, one "real" and one "install" where it presents
itself as mass storage device with windows drivers.

> Apparently, the Windows program running on the guest domain is designed
> to deal with this nonsense, but the question is, Can KVM be configured
> to deal with it? Something like <product id='0x177*'/> would be useful,
> but that doesn't work.

qemu is fine with '-device usb-host,vendorid=0x0c93' which will match
any product with from that vendor.  Dunno about the libvirt side.

cheers,
  Gerd