vfio-user in libvirt

Hi, has anyone considered support for vfio-user devices in libvirt? I was thinking of something like: <controller type='vfio-user' index='0'> <socket type="path">/path/to/vfio-user.sock</socket> <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/> </controller> The main reason why this is useful is to get a PCI slot assigned for PCI-based vfio-user. Thoughts? thanks john