From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f54.google.com (mail-wm0-f54.google.com [74.125.82.54]) by dpdk.org (Postfix) with ESMTP id 42FB837B2 for ; Fri, 26 Feb 2016 21:49:54 +0100 (CET) Received: by mail-wm0-f54.google.com with SMTP id p65so1389255wmp.1 for ; Fri, 26 Feb 2016 12:49:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:organization:user-agent :in-reply-to:references:mime-version:content-transfer-encoding; bh=VP1WHdj/2iD3PC3dZoANRL/Be2N7dBGFiNKYA1J7BwY=; b=WpdZoo3aSefOYJeK+3Q/eObl6EtJUAYJyh27oo67nNI7O+A793zDm7kLa7PcXo73gZ mEtWIfP36cFbm4sZYL6ElvgdlnCGKE0HozL4xYoGiqfyDqOzIVc7Bgrgcma6jC7AQw5d iNqvTUf1VsrMG1xMvKJQHFallQuu/iDsfp2fi85kTafSavkgRXYx9vl08N+1OitTrsge YhUI6d25TMwqVfbbSklXlVKwJg0/HBLK3pwDbXZaVpT2z2qqK8x9cqh7AUSMuIndA5Dw PK3GVDb3GmJXwaLP3VPNxJnQUzWs49MJtBtFbjvyu0uibLz3Y0jV0OeIPdZb69G276k+ Hgdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:organization :user-agent:in-reply-to:references:mime-version :content-transfer-encoding; bh=VP1WHdj/2iD3PC3dZoANRL/Be2N7dBGFiNKYA1J7BwY=; b=bbUUqF73Wrarhg7VqsqjxwaCb7kRh5QeC2JABlfPxGC/LgI0jsx2UhfuPFbOFBY5Ci mKBy+N3nln6UXHENWyKIb+jRFidkaf0JGaLdA+48+ySLKY6tUd78M6TrKOJqghqqtsiU pHzjOgPdK0aQBZzecQNkAuf3JEqhe5aBkjiydeNUur7KNrGBO3gsXoWUh3Pa8Mlgh/XF 3sLqJggrHAoxZH+W8HTiovjYTWOBWB6oQlsjx/lwe2UGRV+RgcAHN8LaIFl4SaNdLV7p h3/qyfm1NYpGwe7sueZ61w4S0yT4IDkOOkWq+k8TE+NWv9JVpbHhab+vFhQ6gV2mIHTK 3B5Q== X-Gm-Message-State: AD7BkJIBV3g8SrMLuOLWWQOECiV+QP9uxHmcW9/X6tEToFcQVp8aRCvPV604yuxOJh4NAE8T X-Received: by 10.194.48.7 with SMTP id h7mr4001971wjn.81.1456519794086; Fri, 26 Feb 2016 12:49:54 -0800 (PST) Received: from xps13.localnet (171.36.101.84.rev.sfr.net. [84.101.36.171]) by smtp.gmail.com with ESMTPSA id 192sm4381603wmw.0.2016.02.26.12.49.52 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 26 Feb 2016 12:49:53 -0800 (PST) From: Thomas Monjalon To: "Wang, Xiao W" Date: Fri, 26 Feb 2016 21:48:20 +0100 Message-ID: <1994581.FACV9pjC7W@xps13> Organization: 6WIND User-Agent: KMail/4.14.10 (Linux/4.1.6-1-ARCH; KDE/4.14.11; x86_64; ; ) In-Reply-To: References: <1454410216-13333-2-git-send-email-xiao.w.wang@intel.com> <4126401.C51dJZWCEs@xps13> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH v3 1/3] fm10k: enable FTAG based forwarding X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Feb 2016 20:49:54 -0000 2016-02-26 09:24, Wang, Xiao W: > Hi, > > > -----Original Message----- > > From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com] > > Sent: Friday, February 26, 2016 5:06 PM > > To: Wang, Xiao W > > Cc: Richardson, Bruce ; Chen, Jing D > > ; dev@dpdk.org > > Subject: Re: [dpdk-dev] [PATCH v3 1/3] fm10k: enable FTAG based forwarding > > > > 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? > > As you know, fm10k has a switch logic between the Mac and Phy, every packets > Sent out from the host will be switched inside the NIC, other NICs don't have > a switch inside, and the FTAG feature is related to the switch function. > > As introduced in the second patch: > The FM10K family of NICs support the addition of a Fabric Tag (FTAG) to carry > special information. The FTAG is placed at the beginning of the frame, it contains > information such as where the packet comes from and goes, and the vlan tag. In > FTAG based forwarding mode, the switch logic forwards packets according to > glort (global resource tag) information, rather than the mac and vlan table. > So this is a feature specific to fm10k. No I still don't think you should consider it specific to fm10k. But yes it is specific to a switch device. I'm OK to have a structure for switch configuration in ethdev.