OVN libvirt

The iface-id value in the “external_ids” column is used by OVS integrations to uniquely identify a VM’s interface. When integrating KVM/Libvirt/OVS with OVN, we’ll need to use this value as well; this provides an “end-to-end” link between an OVN logical port, an OVS virtual port, and a VM’s network interface.

With that bit of background out of the way, let’s look at what’s required to connect a KVM-based VM, using Libvirt and OVS, to OVN:

  • Power on the VM and connect it to OVS. (This is all handled by Libvirt and the Libvirt-OVS integration.)
  • Create an OVN logical port on an OVN logical switch.
  • Populate the addresses associated with the OVN logical port.

Create ovn logical port

  1. ifaceid=$(ovs-vsctl get interface vnet0 external_ids:iface-id)
  2. ovn-nbctl lsp-add <switch name> $IFACE_ID
  3. ovs-vsctl get interface <name> external_ids:attached-mac
  4. MAC_ADDR=$(ovs-vsctl get interface vnet0 external_ids:attached-mac | sed s/\"//g)
  5. ovn-nbctl lsp-set-addresses $IFACE_ID $MAC_ADDR

Populate interfaceid of libvirt config xml

libvirt.xml

  1. <interface type='bridge'>
  2.   <mac address='52:54:00:93:05:25'/>
  3.   <source network='ovs' bridge='br-int'/>
  4.   <virtualport type='openvswitch'>
  5.     <parameters interfaceid='668033d2-06a4-4aaa-aca5-30cde245e477'/>
  6.   </virtualport>
  7.   <target dev='vnet0'/>
  8.   <model type='virtio'/>
  9.   <alias name='net0'/>
  10.   <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
  11. </interface>

参考Using OVN with KVM and Libvirt