From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id BCF7D7EB0 for ; Thu, 4 Dec 2014 08:53:06 +0100 (CET) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP; 03 Dec 2014 23:53:05 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,514,1413270000"; d="scan'208";a="632496349" Received: from kmsmsx153.gar.corp.intel.com ([172.21.73.88]) by fmsmga001.fm.intel.com with ESMTP; 03 Dec 2014 23:53:04 -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, 4 Dec 2014 15:52:27 +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, 4 Dec 2014 15:52:26 +0800 From: "Liu, Jijiang" To: "Zhang, Helin" , Olivier MATZ , "Ananyev, Konstantin" , "dev@dpdk.org" Thread-Topic: [dpdk-dev] [PATCH v5 2/3] mbuf:add three TX ol_flags and repalce PKT_TX_VXLAN_CKSUM Thread-Index: AQHQDkIzZMvV7Xzwn0SVLY5kK7hoh5x9OYaAgAAV4YCAABxsgIABDy2AgACNvrA= Date: Thu, 4 Dec 2014 07:52:26 +0000 Message-ID: <1ED644BD7E0A5F4091CF203DAFB8E4CC01DA0026@SHSMSX101.ccr.corp.intel.com> References: <1417532767-1309-1-git-send-email-jijiang.liu@intel.com> <1417532767-1309-3-git-send-email-jijiang.liu@intel.com> <547EF6E9.5040000@6wind.com> <2601191342CEEE43887BDE71AB977258213BC46D@IRSMSX105.ger.corp.intel.com> <547F211B.3040905@6wind.com> In-Reply-To: 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 Subject: Re: [dpdk-dev] [PATCH v5 2/3] mbuf:add three TX ol_flags and repalce PKT_TX_VXLAN_CKSUM 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, 04 Dec 2014 07:53:07 -0000 Hi Helin, > -----Original Message----- > From: Zhang, Helin > Sent: Thursday, December 4, 2014 2:52 PM > To: Olivier MATZ; Ananyev, Konstantin; Liu, Jijiang; dev@dpdk.org > Subject: RE: [dpdk-dev] [PATCH v5 2/3] mbuf:add three TX ol_flags and rep= alce > PKT_TX_VXLAN_CKSUM >=20 >=20 >=20 > > -----Original Message----- > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Olivier MATZ > > Sent: Wednesday, December 3, 2014 10:42 PM > > To: Ananyev, Konstantin; Liu, Jijiang; dev@dpdk.org > > Subject: Re: [dpdk-dev] [PATCH v5 2/3] mbuf:add three TX ol_flags and > > repalce PKT_TX_VXLAN_CKSUM > > > > Hi Konstantin, > > > > On 12/03/2014 01:59 PM, Ananyev, Konstantin wrote: > > >> I still think having a flag IPV4 + another flag IP_CHECKSUM is not > > >> appropriate. > > > > > > Sorry, didn't get you here. > > > Are you talking about our discussion should PKT_TX_IP_CKSUM and > > PKT_TX_IPV4 be mutually exclusive or not? > > > > Yes > > > > >> I though Konstantin agreed on other flags, but I may have > > >> misunderstood: > > >> > > >> http://dpdk.org/ml/archives/dev/2014-November/009070.html > > > > > > In that mail, I was talking about my suggestion to make > > > PKT_TX_IP_CKSUM, > > PKT_TX_IPV4 and PKT_TX_IPV6 to occupy 2 bits. > > > Something like: > > > #define PKT_TX_IP_CKSUM (1 << X) > > > #define PKT_TX_IPV6 (2 << X) > > > #define PKT_TX_IPV4 (3 << X) > > > > > > "Even better, if we can squeeze these 3 flags into 2 bits. > > > Would save us 2 bits, plus might be handy, as in the PMD you can do: > > > > > > switch (ol_flags & TX_L3_MASK) { > > > case TX_IPV4: > > > ... > > > break; > > > case TX_IPV6: > > > ... > > > break; > > > case TX_IP_CKSUM: > > > ... > > > break; > > > }" > > > > > > As you pointed out, it will break backward compatibility. > > > I agreed with that and self-NACKed it. > > > > ok, so we are back between: > > > > 1/ (Jijiang's patch) > > PKT_TX_IP_CKSUM /* packet is IPv4, and we want hw cksum */ > > PKT_TX_IPV6 /* packet is IPv6 */ > > PKT_TX_IPV4 /* packet is IPv4, and we don't want hw cksum */ > > > > with PKT_TX_IP_CKSUM and PKT_TX_IPV4 exclusive > > > > and > > > > 2/ > > PKT_TX_IP_CKSUM /* we want hw IP cksum */ > > PKT_TX_IPV6 /* packet is IPv6 */ > > PKT_TX_IPV4 /* packet is IPv4 */ > There is another bit flag named 'PKT_TX_IPV4_CSUM' which uses the same bi= t of > 'PKT_TX_IP_CSUM'. It is for identifying if ipv4 hardware checksum offload= is > needed or not. > It seems that we do not need 'PKT_TX_IPV6_CSUM'. > 'PKT_TX_IPV4' and 'PKT_TX_IPV6' just indicates its packet type, and I gue= ss other > features should not be contained in it, according to its name. >=20 > So here I got the option 3: > PKT_TX_IPV4_CKSUM /* we want hw IPv4 cksum */ > PKT_TX_IPV6 /* packet is IPv6 */ > PKT_TX_IPV4 /* packet is IPv4 */ In TX side, if just tell driver/HW this is a IPV4 packet , and don't tell = driver/HW whether TX checksum or other offload is required or not , the = flag is senseless, and hardware will not do any offload. The flag is not used in igb/ixgbe codes, which is just used in i40e codes, = and set this bit(IPv4 packet with no IP checksum offload) in i40e driver. ... } else if (ol_flags & PKT_TX_IPV4) { *td_cmd |=3D I40E_TX_DESC_CMD_IIPT_IPV4; ... =09 > > > > with PKT_TX_IP_CKSUM implies PKT_TX_IPV4 > > > > > > Solution 2/ looks better from a user point of view. Anyone else has an = opinion? > > > > Regards, > > Olivier >=20 > Regards, > Helin