libvir: QEMU error : internal error Failed to add tap interface 'vnet%d' to bridge 'xenbr0' : No such device
Traceback (most recent call last):
  File "/usr/bin/virt-install", line 630, in ?
    main()
  File "/usr/bin/virt-install", line 579, in main
    dom = guest.start_install(conscb,progresscb)
  File "/usr/lib/python2.4/site-packages/virtinst/Guest.py", line 649, in start_install
    return self._do_install(consolecb, meter)
  File "/usr/lib/python2.4/site-packages/virtinst/Guest.py", line 666, in _do_install
    self.domain = self.conn.createLinux(install_xml, 0)
  File "/usr/lib/python2.4/site-packages/libvirt.py", line 480, in createLinux
    if ret is None:raise libvirtError('virDomainCreateLinux() failed', conn=self)
libvirt.libvirtError: virDomainCreateLinux() failed internal error Failed to add tap interface 'vnet%d' to bridge 'xenbr0' : No such device