Subject: Re: [RFC PATCH v2 bpf-next 00/15] xdp_flow: Flow offload to XDP

From: Toshiaki Makita <[email-masked]>
Date: Sun, 27 Oct 2019 22:13:23 +0900

On 19/10/23 (水) 2:45:05, Toke Høiland-Jørgensen wrote:
> John Fastabend <[email-masked]> writes:
> 
>> I think for sysadmins in general (not OVS) use case I would work
>> with Jesper and Toke. They seem to be working on this specific
>> problem.
> 
> We're definitely thinking about how we can make "XDP magically speeds up
> my network stack" a reality, if that's what you mean. Not that we have
> arrived at anything specific yet...
> 
> And yeah, I'd also be happy to discuss what it would take to make a
> native XDP implementation of the OVS datapath; including what (if
> anything) is missing from the current XDP feature set to make this
> feasible. I must admit that I'm not quite clear on why that wasn't the
> approach picked for the first attempt to speed up OVS using XDP...

Here's some history from William Tu et al.
https://linuxplumbersconf.org/event/2/contributions/107/

Although his aim was not to speed up OVS but to add kernel-independent 
datapath, his experience shows full OVS support by eBPF is very difficult.
Later I discussed this xdp_flow approach with William and we find value 
performance-wise in such a way of partial offloading to XDP. TC is one 
of ways to achieve the partial offloading.

Toshiaki Makita