From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 63CD4595B for ; Thu, 13 Nov 2014 04:07:59 +0100 (CET) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga101.fm.intel.com with ESMTP; 12 Nov 2014 19:17:54 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="415786249" Received: from pgsmsx103.gar.corp.intel.com ([10.221.44.82]) by FMSMGA003.fm.intel.com with ESMTP; 12 Nov 2014 19:08:54 -0800 Received: from pgsmsx107.gar.corp.intel.com (10.221.44.105) by PGSMSX103.gar.corp.intel.com (10.221.44.82) with Microsoft SMTP Server (TLS) id 14.3.195.1; Thu, 13 Nov 2014 11:17:50 +0800 Received: from shsmsx151.ccr.corp.intel.com (10.239.6.50) by PGSMSX107.gar.corp.intel.com (10.221.44.105) with Microsoft SMTP Server (TLS) id 14.3.195.1; Thu, 13 Nov 2014 11:17:49 +0800 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.110]) by SHSMSX151.ccr.corp.intel.com ([169.254.3.86]) with mapi id 14.03.0195.001; Thu, 13 Nov 2014 11:17:47 +0800 From: "Liu, Jijiang" To: Thomas Monjalon Thread-Topic: [dpdk-dev] [PATCH v6 1/9] librte_mbuf:the rte_mbuf structure changes Thread-Index: AQHP/nxeFH7scgFPzEikyx13L/39K5xd3XOA Date: Thu, 13 Nov 2014 03:17:47 +0000 Message-ID: <1ED644BD7E0A5F4091CF203DAFB8E4CC01D97183@SHSMSX101.ccr.corp.intel.com> References: <1413881168-20239-1-git-send-email-jijiang.liu@intel.com> <1710340.mrZid3JfsP@xps13> <2835075.ZIuhO63ZWU@xps13> In-Reply-To: <2835075.ZIuhO63ZWU@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 v6 1/9] librte_mbuf:the rte_mbuf structure changes 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 03:08:01 -0000 > -----Original Message----- > From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com] > Sent: Wednesday, November 12, 2014 9:26 PM > To: Liu, Jijiang > Cc: Zhang, Helin; dev@dpdk.org; Richardson, Bruce > Subject: Re: [dpdk-dev] [PATCH v6 1/9] librte_mbuf:the rte_mbuf structure > changes >=20 > Hi guys, >=20 > We still have some problems with the mbuf changes introduced for VXLAN. > I want to raise the packet type issue here. >=20 > 2014-10-23 02:23, Zhang, Helin: > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Thomas Monjalon > > > 2014-10-21 14:14, Liu, Jijiang: > > > > From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com] > > > > > 2014-10-21 16:46, Jijiang Liu: > > > > > > - uint16_t reserved2; /**< Unused field. Required for pad= ding > */ > > > > > > + > > > > > > + /** > > > > > > + * Packet type, which is used to indicate ordinary L2 packet > format and > > > > > > + * also tunneled packet format such as IP in IP, IP in GRE, M= AC in > GRE > > > > > > + * and MAC in UDP. > > > > > > + */ > > > > > > + uint16_t packet_type; > > > > > > > > > > Why not name it "l2_type"? > > > > 'packet_type' is for storing the hardware identified packet type upon > > different layers of protocols (l2, l3, l4, ...). > > It is quite useful for user application or middle layer software > > stacks, it can know what the packet type is without checking the packet= too > much by software. > > Actually ixgbe already has packet types (less than 10), which is transc= oded into > 'ol_flags'. > > For i40e, the packet type can represent about 256 types of packet, > > 'ol_flags' does not have enough bits for it anymore. So put the i40e pa= cket types > into mbuf would be better. > > Also this field can be used for NON-Intel NICs, I think there must be > > the similar concepts of other NICs. And 16 bits 'packet_type' has sever= l > reserved bits for future and NON-Intel NICs. >=20 > Thanks Helin, that's the best description of packet_type I've seen so far= . > It's not so clear in the commit log: > http://dpdk.org/browse/dpdk/commit/?id=3D73b7d59cf4f6faf >=20 > > > > In datasheet, this term is called packet type(s). > > > > > > That's exactly the point I want you really understand! > > > This is a field in generic mbuf structure, so your datasheet has no v= alue here. > > > > > > > Personally , I think packet type is more clear what meaning of thi= s field is . > > > > > > You cannot add an API field without knowing what will be its generic = meaning. > > > Please think about it and describe its scope. >=20 > I integrated this patch with the VXLAN patchset in the hope that you'll i= mprove > the situation afterwards. > This is the answer you recently gave to Olivier: > http://dpdk.org/ml/archives/dev/2014-November/007599.html > " > Regarding adding a packet_type in mbuf, we ever had a lot of discussions > as follows: > http://dpdk.org/ml/archives/dev/2014-October/007027.html > http://dpdk.org/ml/archives/dev/2014-September/005240.html > http://dpdk.org/ml/archives/dev/2014-September/005241.html > http://dpdk.org/ml/archives/dev/2014-September/005274.html > " >=20 > To sum up the situation: > - We don't know what are the possible values of packet_type > - It's only filled by i40e, while other drivers use ol_flags > - There is no special value "unknown" which should be set by drivers > not supporting this feature. > - Its only usage is to print a decimal value in app/test-pmd/rxonly.c >=20 > It's now clear that nobody cares about this part of the API. > So I'm going to remove packet_type from mbuf. > I don't want to keep something that we don't know how to use, that is not > consistent across drivers, and that overlap another API part (ol_flags). The packet type in 40e is very important for user, using packet type can he= lp to speed up packet analysis/identification in their application, especia= lly tunneling packet format. Now I'm working on implementing packet type definition in rte_ethdev.h file= and translation table in i40e, which is almost done.=20 The packet type definition in in rte_ethdev.h file like below.=20 /* * Ethernet packet type */ enum rte_eth_ptype { /* undefined packet type, means HW can't recognise it */ RTE_PTYPE_UNDEF =3D 0, ... /* IPv4 --> GRE/Teredo/VXLAN --> MAC --> IPv4 */ RTE_PTYPE_IPv4_GRENAT_MAC_IPv4FRAG_PAY3, RTE_PTYPE_IPv4_GRENAT_MAC_IPv4_PAY3, RTE_PTYPE_IPv4_GRENAT_MAC_IPv4_UDP_PAY4, RTE_PTYPE_IPv4_GRENAT_MAC_IPv4_TCP_PAY4, RTE_PTYPE_IPv4_GRENAT_MAC_IPv4_SCTP_PAY4, RTE_PTYPE_IPv4_GRENAT_MAC_IPv4_ICMP_PAY4, =20 /* IPv4 --> GRE/Teredo/VXLAN --> MAC --> IPv6 */ RTE_PTYPE_IPv4_GRENAT_MAC_IPv6FRAG_PAY3 RTE_PTYPE_IPv4_GRENAT_MAC_IPv6_PAY3, RTE_PTYPE_IPv4_GRENAT_MAC_IPv6_UDP_PAY4, RTE_PTYPE_IPv4_GRENAT_MAC_IPv6_TCP_PAY4, RTE_PTYPE_IPv4_GRENAT_MAC_IPv6_SCTP_PAY4, RTE_PTYPE_IPv4_GRENAT_MAC_IPv6_ICMP_PAY4, =20 /* IPv4 --> GRE/Teredo/VXLAN --> MAC/VLAN */ RTE_PTYPE_IPv4_GRENAT_MACVLAN_PAY3, ...=20 } Yes, we don't use packet type in many places now, which doesn't mean we don= 't use it in the future( when supporting another tunneling packet). It is ok for me if you want to remove the packet_type filed in mbuf, but w= e will send a separate patch set for introducing packet type in the future,= which includes 1g/10/40g PMD changes. > -- > Thomas