Enable XDP acceleration for Cilium KPR

[ysksuzuki]

What

Enable XDP acceleration for Cilium KPR

neco/cilium/pre/values.yaml

Line 48 in 6c2c6da

acceleration: disabled

kernel 5.15.38 includes virtio-net bug fix, so now we can enable the XDP acceleration.
https://lwn.net/Articles/894357/

Nikolay Aleksandrov (2):
      virtio_net: fix wrong buf address calculation when using xdp

How

• Make sure that the XDP acceleration works on dctest with the latest stable Flatcar
• Check if the XDP acceleration can be properly configured on physical servers before applying stage0
• Evaluate it for a while on stage0 and make sure if it works stably, and then we'll be able to release it on production

Checklist

• Finish implementation of the issue
• Test all functions
• Have enough logs to trace activities
• Notify developers of necessary actions

[ysksuzuki]

Rolling restart Cilium with XDP acceleration enabled disrupts in-cluster connectivity. We need to investigate the cause in an environment where the disruption doesn't affect tenant users.