[ovs-dev] [PATCH v3 0/9] OVS-DPDK flow offload with rte_flow

[Yuanhan Liu]

On Wed, Sep 27, 2017 at 09:12:49AM +0000, Finn Christensen wrote:
> 
>     [Darrell] It looks fine; of course, if we could drop dependencies on cap
>     probe, it would be ideal (.
> 
> 
> [Finn]
> From a Napatech point of view, we would definitely want to use the
> RTE_FLOW_ACTION_TYPE_RSS if it were implement. It definitely makes good
> sense to me. I have 2 reasons for this:
> 1. It would fit nicely into the way Napatech does flow programming in nic
> 2. We would be fully RSS controlled through OVS
> Furthermore, Future RSS splitting on a per megaflow basis will be possible.
> IMO the "pure_mark_cap_probed" function is a temp work-around to make it work.
> The RSS seems to be a solution to the queue problem.

Finn, that's really good to know! I do agree without this probe, it
makes the code simpler and cleaner.

Few questions though. Have Napatech already implemented rss action? If not,
what's the plan? And are you okay with following code?

	add_mark_action();
	add_rss_action_unconditionally();

	flow = rte_create_flow(...);
	if (!flow)
		return -1;

That is, no probes, no feedbacks. If it failed, it just failed (flow
offload then is just skipped).

But I do think some feedbacks are necessary. If we know the rte_flow
cap in the begnning, we could simply disable the flow offload for a
specific port if we know it doesn't have offload ability. This would
avoid the repeat effort of trying to do hw offload completely.

	--yliu