CentOS virt - Nov 2013 - Hot adding USB devices to guests at a fixed address

I have a device I want a guest to see.  I've configured the following:

  % cat /etc/libvirt/HotPlug/owon.xml 
  <hostdev mode='subsystem' type='usb'>
    <source>
      <vendor id='0x5345'/>
      <product id='0x1234'/>
    </source>
  </hostdev>

And then in udev:
  % cat /etc/udev/rules.d/90-owon.rules 
  ACTION=="add", \
    SUBSYSTEM=="usb", \
    SYSFS{idVendor}=="5345", \
    SYSFS{idProduct}=="1234", \
    RUN+="/usr/bin/virsh attach-device XP_VM1
/etc/libvirt/HotPlug/owon.xml"

  ACTION=="remove", \
    SUBSYSTEM=="usb", \
    SYSFS{idVendor}=="5345", \
    SYSFS{idProduct}=="1234", \
    RUN+="/usr/bin/virsh detach-device XP_VM1
/etc/libvirt/HotPlug/owon.xml"

Now this works; I plug the device in and the guest sees it.

The problem is that, each time, it shows up at a different address on
the guest's USB bus.  And, Windows XP being Windows, this means it asks
to load a device driver each and every time (I've never understood why
Windows wants to load a new device driver just because you plug a device
into a different port).

Does anyone know of a way of adding a device so that it's at a known fixed
address inside the guest?

-- 

rgds
Stephen

On Tue, 26 Nov 2013, Stephen Harris wrote:
> I have a device I want a guest to see.  I've configured the following:
> And then in udev:
>   % cat /etc/udev/rules.d/90-owon.rules 
>   ACTION=="add", \
>     SUBSYSTEM=="usb", \
>     SYSFS{idVendor}=="5345", \
>     SYSFS{idProduct}=="1234", \
>     RUN+="/usr/bin/virsh attach-device XP_VM1
/etc/libvirt/HotPlug/owon.xml"
> Now this works; I plug the device in and the guest sees it.
most USB persistent enumeration are done by the device serial 
number, which should appear along with the Vendor and Product.

Can you expose that through the udev rules as well?
 
> Does anyone know of a way of adding a device so that it's at a known
fixed
> address inside the guest?
seeking to 'nail it to' a fixed address is probably not the 
right way to do it, as that is detection order dependant

-- Russ herrold