[R&D] Packet: AF_XDP support

[glazychev-art]

Description

Root issue: networkservicemesh/cmd-forwarder-vpp#859

We recently added AF_XDP support to the forwarder-vpp. But it doesn't work on the Packet cluster.
This is most likely due to the fact that af_xdp vpp plugin doesn't process bonded interfaces (they are used by Packet servers).

[glazychev-art]

Steps to solve the problem:
1. Ask vpp community - https://lists.fd.io/g/vpp-dev/topic/does_af_xdp_plugin_support/98902915
2. Check different settings for bond (see ip link help bond) - 3h
3. Collection and analysis interface statistics (on the kernel and vpp side) - 7h
4. Check vpp af_xdp plugin implementation - 14h
5. Explore some xdp examples from the kernel (see: https://elixir.bootlin.com/linux/v5.15.80/source/samples/bpf) - 7h
6. Explore how bond interface works with xdp (see: torvalds/linux@9e2ee5c7e7c3) - 7h
7. Try the linux kernel v6 - 7h

[glazychev-art]

AF_XDP bond interface discussion - xdp-project/xdp-tutorial#362

[glazychev-art]

We now have 2 options:
Option 1:
Dive into linux kernel and libxdp to find the cause (most likely it is not feasible)
Option 2:
Change server configuration (Equinix Metal server uses bond by default).
We can drop bond in favor of a simple single interface on setup.

[denis-tingaikin]

Currently, it's not possible to implement xdp-project/xdp-tutorial#362 (comment)