[libvirt] Libvirt and QBG with VEB

Hello, I have a setup of virtual machines and wherein my virtual switch (OVS) takes care of switching locally and it uses the network for talking to VM's outside the server (like a VEB scenario I guess). I want Netlink messages to be sent to LLDPAD. I understand that i had to modify the XML files and start the VM. But, i see from the XML that it supports only VEPA, not VEB. But, irrespective of VEB or VEPA, those VM information should be known to the upstream switch through VDP. 802.1QBG seem to support this (both VEPA and VEB) http://www.ieee802.org/1/files/private/bg-drafts/d2/802-1qbg-d2-2.pdf But, for VEB, no net link messages are sent by libvirt. Why is that? From the XML example, I see that: <interface type=’direct’> <mac address=’d0:0f:d0:0f:02:01’/> <source dev=’eth2.20’ mode=’vepa’/> <source network=’default’/> <virtualport type=’802.1Qbg’> <parameters managerid=’12’ typeid=’0x123456’ typeidversion=’1’ instanceid=’09b00c53-8b5c-4eeb-8f00-d847aa05191b’ /> </virtualport> I tried different combinations by changing the interface type to bridge and and trying Qbg as in below, I find that it doesn't send a Netlink message to LLDPAD. There's no "mode=veb".  </controller>     <interface type='bridge'>       <mac address='00:54:00:4e:46:04'/>       <source bridge='xml_br'/>       <virtualport type='802.1Qbg'>         <parameters managerid='12' typeid='1193046' typeidversion='1' instanceid='09b00c53-8b5c-4eeb-8f00-d847aa05191b'/>       </virtualport>       <target dev='tap_xml'/>       <model type='virtio'/>       <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>     </interface> How do i get this to work? Is this a limitation? Thanks,KP