From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruce Richardson Subject: Re: [PATCH v3 1/3] fm10k: enable FTAG based forwarding Date: Fri, 26 Feb 2016 16:33:09 +0000 Message-ID: <20160226163309.GA28808@bricha3-MOBL3> References: <1454410216-13333-2-git-send-email-xiao.w.wang@intel.com> <20160225161406.GA22772@bricha3-MOBL3> <4126401.C51dJZWCEs@xps13> <20160226144852.GC21628@bricha3-MOBL3> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "dev@dpdk.org" To: David Marchand Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 334E75398 for ; Fri, 26 Feb 2016 17:33:14 +0100 (CET) Content-Disposition: inline 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" On Fri, Feb 26, 2016 at 04:00:49PM +0100, David Marchand wrote: > On Fri, Feb 26, 2016 at 3:48 PM, Bruce Richardson > wrote: > > On Fri, Feb 26, 2016 at 09:24:06AM +0000, Wang, Xiao W wrote: > >> Hi, > >> > > 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. > > > > If it is fm10k specific, how about just adding a public function to the fm10k > > driver to turn it on. The user app will be non-portable across NICs, but > > that's the price of using nic-specific features. > > What about using a devargs ? > Something like : > -w xxxx:xx:xx.x,enable_ftag=1 > > The application still needs to know about this to enable it, but that > sounds better to me. > The only issue is that it can't work with hotplug at the moment. > Seems a good enough solution to me. Xiao, any other thoughts? /Bruce