The PoC of this solution must:

• create a VM in CNV having both the MAC and IP addresses defined at creation time
• the created VM must be attached to a primary UDN (overlay) with IPAM
• when migrated / stopped then started / restarted the VM's MAC and IPs must be preserved
• existing east/west TCP connections must be preserved when migrating the VM
• existing north/south TCP connections must be preserved when migrating the VM
• the VM must be able to egress from the overlay network to the internet

The PoC should:

• focus on the ipam-extensions mutating webhook to mutate the launcher pods to request particular MAC and IP addresses
  • the VM's will have an annotation for which IP addr to use for the primary UDN interface. The final solution will not have this - this is just for the sake of the PoC.
  • the mutating webhook shall read the annotation on the VM, and the MAC addr request on the interface which is attached to a primary UDN network, and with that information generate a multus-default-network annotation to request both the MAC address and the IP address of the pod's primary UDN attachment
• OVN-Kubernetes should be changed to support reading IP and MAC requests for the primary UDN attachment from the default-network annotation
• OVN-Kubernetes should be changed to allow a specific IP address to be requested from the allocator
• OVN-Kubernetes throws an error when an IP is requested via NSE and and IPAMClaim is provided. We need to work-around that.

NOTE: 

• in https://github.com/ovn-kubernetes/ovn-kubernetes/pull/4732 you can find how to consume the default network annotation on OVN-Kubernetes (to read the IPAMClaim reference).
• in https://github.com/kubevirt/ipam-extensions/pull/69/files you can find a way to generate the multus default network annotation on the ipam-extensions project