Comment 18 for bug 1677398

In the same scope of required "out of context information" fall cases of vfio devices for hostdevs.
Those work fine if defined in the guest or added to the guest.

But if only referred by an interface like:
    <interface type='network'>
      <mac address='3a:73:83:14:99:0e'/>
      <source network='pf-et0p0' portgroup='storage'/>
      <model type='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </interface>

And the definition being external like:
<network>
  <name>pf-et0p0</name>
  <uuid>c1415c6d-11d7-417e-8113-ed5439e5ee44</uuid>
  <forward mode='hostdev' managed='yes'>
    <driver name='vfio'/>
    <pf dev='et0p0'/>
  </forward>
  <portgroup name='ext' default='yes'>
    <vlan>
      <tag id='30'/>
    </vlan>
  </portgroup>
  <portgroup name='lab2'>
    <vlan>
      <tag id='51'/>
    </vlan>
  </portgroup>
  <portgroup name='storage'>
    <vlan>
      <tag id='61'/>
    </vlan>
  </portgroup>
</network>

It fails.
As again in this case virt-aa-helper has no means yet to introspect the extra info needed to convert all this to paths.