Re: XDP seeking input from NIC hardware vendors

[Jakub Kicinski via iovisor-dev <iovisor-dev-9jONkmmOlFHEE9lA1F8Ukti2O/JbrIOy@public.gmane.org>]

On Thu, 7 Jul 2016 19:22:12 -0700, Alexei Starovoitov wrote:
> > If the goal is to just separate XDP traffic from non-XDP traffic you could accomplish this with a combination of SR-IOV/macvlan to separate the device queues into multiple netdevs and then run XDP on just one of the netdevs. Then use flow director (ethtool) or 'tc cls_u32/flower' to steer traffic to the netdev. This is how we support multiple networking stacks on one device by the way it is called the bifurcated driver. Its not too far of a stretch to think we could offload some simple XDP programs to program the splitting of traffic instead of cls_u32/flower/flow_director and then you would have a stack of XDP programs. One running in hardware and a set running on the queues in software.  
> 
> the above sounds like much better approach then Jesper/mine prog_per_ring stuff.
> If we can split the nic via sriov and have dedicated netdev via VF just for XDP that's way cleaner approach.
> I guess we won't need to do xdp_rxqmask after all.

+1

I was thinking about using eBPF to direct to NIC queues but concluded
that doing a redirect to a VF is cleaner.  Especially if the PF driver
supports VF representatives we could potentially just use
bpf_redirect(VFR netdev) and the VF doesn't even have to be handled by
the same stack.