From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrien Mazarguil Subject: Re: [PATCH v3 04/14] net/mlx5: support Rx tunnel type identification Date: Mon, 16 Apr 2018 15:47:37 +0200 Message-ID: <20180416134737.GZ4957@6wind.com> References: <20180410133415.189905-1-xuemingl%40mellanox.com> <20180413112023.106420-5-xuemingl@mellanox.com> <20180413130237.kb4dkx7o6lamrjoq@laranjeiro-vm.dev.6wind.com> <20180416072857.gyfcvfqoxu3gfepf@laranjeiro-vm.dev.6wind.com> <20180416092825.GW4957@6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: =?utf-8?B?TsOpbGlv?= Laranjeiro , Shahaf Shuler , "dev@dpdk.org" , Olivier Matz To: "Xueming(Steven) Li" Return-path: Received: from mail-wr0-f174.google.com (mail-wr0-f174.google.com [209.85.128.174]) by dpdk.org (Postfix) with ESMTP id B3FF78DA7 for ; Mon, 16 Apr 2018 15:47:51 +0200 (CEST) Received: by mail-wr0-f174.google.com with SMTP id u11so26213503wri.12 for ; Mon, 16 Apr 2018 06:47:51 -0700 (PDT) Content-Disposition: inline In-Reply-To: List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Mon, Apr 16, 2018 at 01:32:49PM +0000, Xueming(Steven) Li wrote: > > > -----Original Message----- > > From: Adrien Mazarguil > > Sent: Monday, April 16, 2018 5:28 PM > > To: Xueming(Steven) Li > > Cc: Nélio Laranjeiro ; Shahaf Shuler ; dev@dpdk.org; > > Olivier Matz > > Subject: Re: [PATCH v3 04/14] net/mlx5: support Rx tunnel type identification > > > > On Mon, Apr 16, 2018 at 08:05:13AM +0000, Xueming(Steven) Li wrote: > > > > > > > > > > -----Original Message----- > > > > From: Nélio Laranjeiro > > > > Sent: Monday, April 16, 2018 3:29 PM > > > > To: Xueming(Steven) Li > > > > Cc: Shahaf Shuler ; dev@dpdk.org; Olivier Matz > > > > ; Adrien Mazarguil > > > > > > > > Subject: Re: [PATCH v3 04/14] net/mlx5: support Rx tunnel type > > > > identification > > > > > > > > On Sat, Apr 14, 2018 at 12:57:58PM +0000, Xueming(Steven) Li wrote: > > > > > +Adrien > > > > > > > > > > > -----Original Message----- > > > > > > From: Nélio Laranjeiro > > > > > > Sent: Friday, April 13, 2018 9:03 PM > > > > > > To: Xueming(Steven) Li > > > > > > Cc: Shahaf Shuler ; dev@dpdk.org; Olivier > > > > > > Matz > > > > > > Subject: Re: [PATCH v3 04/14] net/mlx5: support Rx tunnel type > > > > > > identification > > > > > > > > > > > > +Olivier, > > > > > > > > > > > > On Fri, Apr 13, 2018 at 07:20:13PM +0800, Xueming Li wrote: > > > > > > > This patch introduced tunnel type identification based on flow rules. > > > > > > > If flows of multiple tunnel types built on same queue, > > > > > > > RTE_PTYPE_TUNNEL_MASK will be returned, user application could > > > > > > > use bits in flow mark as tunnel type identifier. > > > > > > > > > > > > For an application it will mean the packet embed all tunnel > > > > > > types defined in DPDK, to make such thing you need a > > > > > > RTE_PTYPE_TUNNEL_UNKNOWN which does not exists currently. > > > > > > > > > > There was a RTE_PTYPE_TUNNEL_UNKNOWN definition, but removed due > > > > > to > > > > discussion. > > > > > So I think it good to add it in the patchset of reviewed by Adrien. > > > > > > > > Agreed, > > > > > > > > > > > > > > > Even with it, the application still needs to parse the packet to > > > > > > discover which tunnel the packet embed, is there any benefit > > > > > > having such bit? Not so sure. > > > > > > > > > > With a tunnel flag, checksum status represent inner checksum. > > > > > > > > Not sure this is generic enough, MLX5 behaves as this, but how > > > > behaves other NICs? It should have specific bits for inner checksum > > > > if all NIC don't have the same behavior. > > > > > > From my understanding, if outer checksum invalid, the packet can't be > > > received as a tunneled packet, but a normal packet, thus checksum > > > flags always result of inner for a valid tunneled packet. > > > > Yes, since checksum validation information covers all layers at once (outermost to the innermost > > recognized), the presence of an "unknown tunnel" > > bit implicitly means outer headers are OK. > > > > Now regarding the addition of RTE_PTYPE_TUNNEL_UNKNOWN, the main issue I see is that it's implicit, as > > in getting 0 after and'ing packet types with RTE_PTYPE_TUNNEL_MASK means either not present or unknown > > type. > > How about define RTE_PTYPE_TUNNEL_UNKNOWN same ask RTE_PTYPE_TUNNEL_MASK? And'ding packet types always > return a non-zero value. I mean the value already exists, it's implicitly 0. Adding one with the same value as RTE_PTYPE_TUNNEL_MASK could be seen as a waste of a value otherwise usable for an actual tunnel type (there are only 4 bits). > > How about not setting any tunnel bit and let applications rely on the presence of RTE_PTYPE_INNER_* to > > determine that there is a tunnel of unknown type? The rationale being that a tunneled packet without > > an inner payload is kind of pointless anyway. > > An unknown type doesn't break anything, neither enum bits, straightforward IMHO. Keep in mind that mbuf packet types report what is identified. All the definitions in this file name a specific protocol. For instance there is no such definition as "L3 present" or "L4 present". "Tunnel present" doesn't make a lot of sense on its own either. Don't you agree that reporting at least one inner ptype while leaving tunnel ptype to 0 automatically addresses this issue? > > > > > Setting flow mark for different flow type could save time of > > > > > parsing > > > > tunnel. > > > > > > > > Thanks, > > > > > > > > -- > > > > Nélio Laranjeiro > > > > 6WIND > > > > -- > > Adrien Mazarguil > > 6WIND -- Adrien Mazarguil 6WIND