From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH v3 1/3] fm10k: enable FTAG based forwarding Date: Fri, 26 Feb 2016 10:06:18 +0100 Message-ID: <4126401.C51dJZWCEs@xps13> References: <1454410216-13333-2-git-send-email-xiao.w.wang@intel.com> <20160225161406.GA22772@bricha3-MOBL3> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: dev@dpdk.org To: "Wang, Xiao W" Return-path: Received: from mail-wm0-f52.google.com (mail-wm0-f52.google.com [74.125.82.52]) by dpdk.org (Postfix) with ESMTP id 8EE97902 for ; Fri, 26 Feb 2016 10:07:52 +0100 (CET) Received: by mail-wm0-f52.google.com with SMTP id c200so63223446wme.0 for ; Fri, 26 Feb 2016 01:07:52 -0800 (PST) In-Reply-To: List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 2016-02-26 04:31, Wang, Xiao W: > From: Richardson, Bruce > > On Thu, Feb 25, 2016 at 03:45:45PM +0000, Chen, Jing D wrote: > > > From: Richardson, Bruce > > > > On Thu, Feb 25, 2016 at 10:04:02AM +0000, Chen, Jing D wrote: > > > > > This feature is trying to use FTAG (a unique tech in fm10k) > > > > > instead of mac/vlan to forward packets. App need a way to tell PMD > > > > > driver that which forwarding style it would like to use. > > > > > > > > Why not just specify this in the port configuration at setup time? > > > > > > > > > > Please educate me. I think the port configuration flags are also > > > common to all PMD Drivers. Is it possible to add a flag like "RTE_USE_FTAG" > > and pass to PMD driver? > > > > > They are. > > For something PMD specific, like FTAG, it's always a challenge, and I don't > > know off the top of my head if there is a simple option. However, given the > > choice between an mbuf flag and a port config flag, I'd always choose the > > former. > > Other alternatives would be to have a fm10k specific API in the fm10k driver > > alone. > > > > I'll let Thomas as ethdev maintainer comment if he has other suggestions as to > > how to handle this case. I suspect this won't be the first device-specific piece of > > functionality we need to deal with. > > > > /Bruce > > Whatever method we choose, we have to find a way for the user to express his need > for FTAG, it maybe a build time config option, or a port config flag (no such flag now), > or a fast path flag in mbuf (no such flag now) etc. For the customer Topsec's use case, > they use FTAG for all the TX packets, so all the above methods (per build config, per > port config, per mbuf config) can meet their need. Since the pmd frame work is for > common, it's hard to add new fields only for one specific NIC, so I add a build time > config and make an introduction in the doc. > > Thanks for the discussion, Thomas, do you have any suggestions? I don't understand why you say this feature is specific to fm10k. Can we imagine another NIC having this capability? I think it must be an port configuration, as Bruce suggested. What about a field in struct rte_eth_conf?