Integration With Off-path Network Backends

Off-path SmartNICs (or DPUs) introduce an architecture change where network agents responsible for eSwitch configuration and representor interface plugging run on a separate SoC with its own CPU, memory and that runs a separate OS kernel. The side-effect of that is that hypervisor hostnames no longer match SmartNIC (DPU) hostnames which are seen by OVS and OVN agents while the existing port binding code relies on that. The goal of this specification is to introduce changes necessary to extend the existing hardware offload code to cope with the hostname mismatch and related design challenges while reusing the rest of the code. To do that, PCI(e) add-in card tracking is introduced for boards with unique serial numbers so that it can be used to determine the correct hostname of a SmartNIC on which networking agents will program the necessary flows and do the necessary port plugging. Additionally, more information is suggested to be passed in the "binding:profile" during a port update to facilitate representor port plugging.