usb-port-autoassign.xml

<domain type='qemu'>
  <name>QEMUGuest1</name>
  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
  <memory unit='KiB'>219136</memory>
  <currentMemory unit='KiB'>219136</currentMemory>
  <vcpu placement='static'>1</vcpu>
  <os>
    <type arch='i686' machine='pc'>hvm</type>
    <boot dev='hd'/>
  </os>
  <devices>
    <emulator>/usr/bin/qemu-system-i686</emulator>
    <controller type='usb' index='0'/>
    <memballoon model='virtio'/>
    <hub type='usb'>
      <address type='usb' bus='0' port='1'/>
    </hub>
    <input type='mouse' bus='usb'>
    </input>
    <hub type='usb'>
    </hub>
    <input type='mouse' bus='usb'>
    </input>
    <input type='mouse' bus='usb'>
    </input>
  </devices>
</domain>