From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id C472F595B for ; Thu, 13 Nov 2014 06:25:32 +0100 (CET) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP; 12 Nov 2014 21:28:53 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="415825425" Received: from kmsmsx153.gar.corp.intel.com ([172.21.73.88]) by FMSMGA003.fm.intel.com with ESMTP; 12 Nov 2014 21:26:25 -0800 Received: from shsmsx102.ccr.corp.intel.com (10.239.4.154) by KMSMSX153.gar.corp.intel.com (172.21.73.88) with Microsoft SMTP Server (TLS) id 14.3.195.1; Thu, 13 Nov 2014 13:35:06 +0800 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.110]) by shsmsx102.ccr.corp.intel.com ([169.254.2.216]) with mapi id 14.03.0195.001; Thu, 13 Nov 2014 13:35:04 +0800 From: "Liu, Jijiang" To: Thomas Monjalon Thread-Topic: [dpdk-dev] [PATCH v8 10/10] app/testpmd:test VxLAN Tx checksum offload Thread-Index: AQHP8Yux0VUY397yik2xjVM3DjesSpxPpsiAgAGaY5CAABv8AIAIEl8ggAAq4wCAAVxhEIAB236AgAFNa4A= Date: Thu, 13 Nov 2014 05:35:02 +0000 Message-ID: <1ED644BD7E0A5F4091CF203DAFB8E4CC01D99258@SHSMSX101.ccr.corp.intel.com> References: <1414376006-31402-1-git-send-email-jijiang.liu@intel.com> <5460E512.1050609@6wind.com> <1ED644BD7E0A5F4091CF203DAFB8E4CC01D8F7A7@SHSMSX101.ccr.corp.intel.com> <176980123.CbUgamS8oi@xps13> In-Reply-To: <176980123.CbUgamS8oi@xps13> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [PATCH v8 10/10] app/testpmd:test VxLAN Tx checksum offload 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: Thu, 13 Nov 2014 05:25:33 -0000 > -----Original Message----- > From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com] > Sent: Thursday, November 13, 2014 1:26 AM > To: Liu, Jijiang > Cc: dev@dpdk.org; Olivier MATZ > Subject: Re: [dpdk-dev] [PATCH v8 10/10] app/testpmd:test VxLAN Tx checks= um > offload >=20 > 2014-11-11 05:29, Liu, Jijiang: > > From: Olivier MATZ > > > On 11/10/2014 07:03 AM, Liu, Jijiang wrote: > > > > > - if PKT_TX_VXLAN_CKSUM is not set (legacy use case), then the > > > > > driver use l2_len and l3_len to offload inner IP/UDP/TCP check= sums. > > > > > > > > If the flag is not set, and imply that it is not VXLAN packet, > > > > and do TX checksum offload as regular packet. > > > > > > > > > - if PKT_TX_VXLAN_CKSUM is set, then the driver has to use > > > > > inner_l{23}_len instead of l{23}_len for the same operation. > > > > > > > > Your understanding is not fully correct. > > > > The l{23}_len is still used for TX checksum offload, please refer > > > > to > > > > i40e_txd_enable_checksum() implementation. > > > > > > This fields are part of public mbuf API. You cannot say to refer to > > > i40e PMD code to understand how to use it. > > > > > > > > Adding PKT_TX_VXLAN_CKSUM changes the semantic of l2_len and > l3_len. > > > > > To fix this, I suggest to remove the new fields inner_l{23}_len > > > > > then add outer_l{23}_len instead. Therefore, the semantic of > > > > > l2_len and l3_len would not change, and a driver would always > > > > > use the same field for a specific offload. > > > > > > > > Oh... > > > > > > Does it mean you agree? > > > > I don't agree to change inner_l{23}_len the name. > > The reason is that using the "inner" word means incoming packet is tunn= eling > packet or encapsulation packet. > > if we add "outer"{2,3}_len, which will cause confusion when processing = non- > tunneling packet. >=20 > Sorry Jijiang, maybe I don't understand what you are saying, but I think = you > missed something. Let me explain the problem. >=20 > For PKT_TX_IP_CKSUM, we must set l{2,3}_len. > When PKT_TX_VXLAN_CKSUM is set, PKT_TX_IP_CKSUM is related to inner IP, > right? First of all, I want to explain that what PKT_TX_VXLAN_CKSUM meaning is, w= hen the flag is set, driver know that it need set TX checksum for whole pac= ket, not only for inner part.=20 So When PKT_TX_VXLAN_CKSUM is set, PKT_TX_IP_CKSUM is related to inner IP,r= ight? > So we must set inner_l{2,3}_len. > It means that PKT_TX_IP_CKSUM requires different fields to be set, depend= ing of > PKT_TX_VXLAN_CKSUM. That's what Olivier calls a semantic change. > It's not acceptable for an API. >=20 > PKT_TX_IP_CKSUM should always be related to l{2,3}_len. > When PKT_TX_VXLAN_CKSUM is set, we should add outer_l{2,3}_len. >=20 > Please, correct me if I'm wrong or fix the API. >=20 > Thanks > -- > Thomas