From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 721DB1515 for ; Thu, 27 Nov 2014 17:31:48 +0100 (CET) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP; 27 Nov 2014 08:31:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,470,1413270000"; d="scan'208";a="615088319" Received: from pgsmsx105.gar.corp.intel.com ([10.221.44.96]) by orsmga001.jf.intel.com with ESMTP; 27 Nov 2014 08:31:45 -0800 Received: from shsmsx152.ccr.corp.intel.com (10.239.6.52) by pgsmsx105.gar.corp.intel.com (10.221.44.96) with Microsoft SMTP Server (TLS) id 14.3.195.1; Fri, 28 Nov 2014 00:31:44 +0800 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.110]) by SHSMSX152.ccr.corp.intel.com ([169.254.6.5]) with mapi id 14.03.0195.001; Fri, 28 Nov 2014 00:31:43 +0800 From: "Liu, Jijiang" To: Olivier MATZ Thread-Topic: [dpdk-dev] [PATCH 0/3] i40e VXLAN TX checksum rework Thread-Index: AQHQChvO5Hbj694uHUagPyQ5KbGpNZxzszuAgABgc4CAAJbOQA== Date: Thu, 27 Nov 2014 16:31:41 +0000 Message-ID: <1ED644BD7E0A5F4091CF203DAFB8E4CC01D9EF72@SHSMSX101.ccr.corp.intel.com> References: <1417076319-629-1-git-send-email-jijiang.liu@intel.com> <5476F28F.7010802@6wind.com> <2601191342CEEE43887BDE71AB977258213BADE4@IRSMSX105.ger.corp.intel.com> In-Reply-To: <2601191342CEEE43887BDE71AB977258213BADE4@IRSMSX105.ger.corp.intel.com> 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 0/3] i40e VXLAN TX checksum rework 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, 27 Nov 2014 16:31:49 -0000 > -----Original Message----- > From: Ananyev, Konstantin > Sent: Thursday, November 27, 2014 11:30 PM > To: Olivier MATZ; Liu, Jijiang; dev@dpdk.org > Subject: RE: [dpdk-dev] [PATCH 0/3] i40e VXLAN TX checksum rework >=20 > Hi Oliver, >=20 > > -----Original Message----- > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Olivier MATZ > > Sent: Thursday, November 27, 2014 9:45 AM > > To: Liu, Jijiang; dev@dpdk.org > > Subject: Re: [dpdk-dev] [PATCH 0/3] i40e VXLAN TX checksum rework > > > > Hi Jijiang, > > > > Please find below some comments about the specifications. The global > > picture looks fine to me. > > > > I've not reviewed the patch right now, but it's in the pipe. > > > > On 11/27/2014 09:18 AM, Jijiang Liu wrote: > > > We have got some feedback about backward compatibility of VXLAN TX > > > checksum offload API with 1G/10G NIC after the i40e VXLAN > > TX checksum codes were applied, so we have to rework the APIs on i40e, > including the changes of mbuf, i40e PMD and csum engine. > > > > > > The main changes in mbuf are as follows, In place of removing > > > PKT_TX_VXLAN_CKSUM, we introducing 2 new flags: > PKT_TX_OUT_IP_CKSUM, > > > PKT_TX_UDP_TUNNEL_PKT, > > and a new field: l4_tun_len. > > > > What about PKT_TX_OUT_UDP_CKSUM instead of > PKT_TX_UDP_TUNNEL_PKT? It's > > maybe more coherent with the other names. >=20 > FVL HW don't support outer L4 checksum offload. > But to calculate inner checksums correctly, it needs a hint from SW about= L4 > Tunnelling Type. >=20 > > > > > > > Replace the inner_l2_len and the inner_l3_len field with the outer_l2= _len and > outer_l3_len field. > > > > > > The existing flags are listed below, > > > PKT_TX_IP_CKSUM: HW IPv4 checksum for non-tunnelling packet/ HW > inner IPv4 checksum for tunnelling packet > > > PKT_TX_TCP_CKSUM: HW TCP checksum for non-tunnelling packet/ HW > inner TCP checksum for tunnelling packet > > > PKT_TX_SCTP_CKSUM: HW SCTP checksum for non-tunnelling packet/ HW > inner SCTP checksum for tunnelling packet > > > PKT_TX_UDP_CKSUM: HW SCTP checksum for non-tunnelling packet/ HW > inner SCTP checksum for tunnelling packet > > > PKT_TX_IPV4: IPv4 with no HW checksum offload for non-tunnelli= ng > packet/inner IPv4 with no HW checksum offload for > > tunnelling packet > > > PKT_TX_IPV6: IPv6 non-tunnelling packet/ inner IPv6 with no HW > checksum offload for tunnelling packet > > > > As I suggested in the TSO thread, I think the following semantics is > > easier to understand for the user: > > > > - PKT_TX_IP_CKSUM: tell the NIC to compute IP cksum > > > > - PKT_TX_IPV4: tell the NIC it's an IPv4 packet. Required for L4 > > checksum offload or TSO. > > > > - PKT_TX_IPV6: tell the NIC it's an IPv6 packet. Required for L4 > > checksum offload or TSO. > > > > I think it won't make a big difference in the FVL driver. >=20 > No, no big difference here, but I still think it will be a bit cleaner if= all 3 flags would > be nutually exclusive. > In fact, we can unite all 3 of them them into 2 bits, same as we doin= g for L4 > checksum flags. >=20 > > > > > > > let's use a few examples to demonstrate how to use these flags: > > > Let say we have a tunnel packet: > > > eth_hdr_out/ipv4_hdr_out/udp_hdr_out/vxlan_hdr/ehtr_hdr_in/ipv4_hdr_ > > > in/tcp_hdr_in.There > > could be several scenarios: > > > > > > A) User requests HW offload for ipv4_hdr_out checksum. > > > He doesn't care is it a tunnelled packet or not. > > > So he sets: > > > > > > mb->l2_len =3D eth_hdr_out; > > > mb->l3_len =3D ipv4_hdr_out; > > > mb->ol_flags |=3D PKT_TX_IPV4_CSUM; > > > > > > B) User is aware that it is a tunnelled packet and requests HW offloa= d for > ipv4_hdr_in and tcp_hdr_in *only*. > > > He doesn't care about outer IP checksum offload. > > > In that case, for FVL he has 2 choices: > > > 1. Treat that packet as a 'proper' tunnelled packet, and fill all= the fields: > > > mb->l2_len =3D eth_hdr_in; > > > mb->l3_len =3D ipv4_hdr_in; > > > mb->outer_l2_len =3D eth_hdr_out; > > > mb->outer_l3_len =3D ipv4_hdr_out; > > > mb->l4tun_len =3D vxlan_hdr; > > > mb->ol_flags |=3D PKT_TX_UDP_TUNNEL_PKT | PKT_TX_IP_CKSUM | > > > PKT_TX_TCP_CKSUM; > > > > > > 2. As user doesn't care about outer IP hdr checksum, he can treat > everything before ipv4_hdr_in as L2 header. > > > So he knows, that it is a tunnelled packet, but makes HW to treat= it as > ordinary (non-tunnelled) packet: > > > mb->l2_len =3D eth_hdr_out + ipv4_hdr_out + udp_hdr_out + vxlan= _hdr + > ehtr_hdr_in; > > > mb->l3_len =3D ipv4_hdr_in; > > > mb->ol_flags |=3D PKT_TX_IP_CKSUM | PKT_TX_TCP_CKSUM; > > > > > > i40e PMD will support both B.1 and B.2. > > > ixgbe/igb/em PMD supports only B.2. > > > if HW supports both - it will be up to user app which method to choos= e. > > > > I think we should have a flag to advertise outer ip and outer udp > > checksum offload support, so the application knows which mode can be > > used. >=20 > You mean a new DEV_TX_OFFLOAD_* value, right? > Something like: DEV_TX_OFFLOAD_UDP_TUNNEL? > And make i40e_dev_info_get() to return it? > Yes, forgot about it, sounds like a proper thing to do. Yes, makes sense, I will send a separate patch(bug fixing) to do this. Than= ks . > Konstantin >=20 > > > > > > Regards, > > Olivier