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 DACB25A34 for ; Wed, 11 Nov 2015 12:10:16 +0100 (CET) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP; 11 Nov 2015 03:10:15 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,275,1444719600"; d="scan'208";a="834100502" Received: from fmsmsx107.amr.corp.intel.com ([10.18.124.205]) by fmsmga001.fm.intel.com with ESMTP; 11 Nov 2015 03:10:15 -0800 Received: from fmsmsx101.amr.corp.intel.com (10.18.124.199) by fmsmsx107.amr.corp.intel.com (10.18.124.205) with Microsoft SMTP Server (TLS) id 14.3.248.2; Wed, 11 Nov 2015 03:10:15 -0800 Received: from shsmsx104.ccr.corp.intel.com (10.239.4.70) by fmsmsx101.amr.corp.intel.com (10.18.124.199) with Microsoft SMTP Server (TLS) id 14.3.248.2; Wed, 11 Nov 2015 03:10:15 -0800 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.83]) by SHSMSX104.ccr.corp.intel.com ([169.254.5.223]) with mapi id 14.03.0248.002; Wed, 11 Nov 2015 19:10:13 +0800 From: "Liu, Jijiang" To: "Xu, Qian Q" , Yuanhan Liu Thread-Topic: [dpdk-dev] [PATCH v4 7/8] virtio/lib:add virtio guest offload capabilities Thread-Index: AQHRHEv/9kTOw3jhcUuIrjChZUXedp6V9/cAgACHpbD//3v+gIAAh9Ng//974QCAAKoQgA== Date: Wed, 11 Nov 2015 11:10:12 +0000 Message-ID: <1ED644BD7E0A5F4091CF203DAFB8E4CC22BDA7C6@SHSMSX101.ccr.corp.intel.com> References: <1447224046-1169-1-git-send-email-jijiang.liu@intel.com> <1447224046-1169-8-git-send-email-jijiang.liu@intel.com> <20151111083118.GA2326@yliu-dev.sh.intel.com> <1ED644BD7E0A5F4091CF203DAFB8E4CC22BDA719@SHSMSX101.ccr.corp.intel.com> <20151111084419.GC2326@yliu-dev.sh.intel.com> <1ED644BD7E0A5F4091CF203DAFB8E4CC22BDA74A@SHSMSX101.ccr.corp.intel.com> <82F45D86ADE5454A95A89742C8D1410E0317AEE3@shsmsx102.ccr.corp.intel.com> In-Reply-To: <82F45D86ADE5454A95A89742C8D1410E0317AEE3@shsmsx102.ccr.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" , "Michael S. Tsirkin" Subject: Re: [dpdk-dev] [PATCH v4 7/8] virtio/lib:add virtio guest offload capabilities 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: Wed, 11 Nov 2015 11:10:17 -0000 Hi Qian, >=20 > -----Original Message----- > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Liu, Jijiang > Sent: Wednesday, November 11, 2015 4:53 PM > To: Yuanhan Liu > Cc: dev@dpdk.org; Michael S. Tsirkin > Subject: Re: [dpdk-dev] [PATCH v4 7/8] virtio/lib:add virtio guest offloa= d > capabilities >=20 >=20 >=20 > > -----Original Message----- > > From: Yuanhan Liu [mailto:yuanhan.liu@linux.intel.com] > > Sent: Wednesday, November 11, 2015 4:44 PM > > To: Liu, Jijiang > > Cc: Michael S. Tsirkin; dev@dpdk.org > > Subject: Re: [dpdk-dev] [PATCH v4 7/8] virtio/lib:add virtio guest > > offload capabilities > > > > On Wed, Nov 11, 2015 at 08:38:29AM +0000, Liu, Jijiang wrote: > > > > > > > > > > -----Original Message----- > > > > From: Yuanhan Liu [mailto:yuanhan.liu@linux.intel.com] > > > > Sent: Wednesday, November 11, 2015 4:31 PM > > > > To: Liu, Jijiang; Michael S. Tsirkin > > > > Cc: dev@dpdk.org > > > > Subject: Re: [dpdk-dev] [PATCH v4 7/8] virtio/lib:add virtio guest > > > > offload capabilities > > > > > > > > I don't think we need that, and it might be wrong to set those > > > > fields at > > vhost. > > > > > > > > And, TBH, I am not 100% sure that I understand what those flags > > > > truely are and for. All I know is that they seem have something to > > > > do with QEMU/TAP device. > > > > > > According to virtio standard, those fileds should be set. > > > > If so, you'd better quote them here, or even to your patch commit. >=20 > In the Virtual I/O Device (VIRTIO) Version 1.0 Committee Specification 02= , >=20 >=20 > [QIAN] Do we support virtio 1.0 in the vhost offload case? Currently it's= virtio > 0.95 Spec that we are testing. >=20 There are almost same description in 0.95 Spec, (1)VIRTIO_NET_F_GUEST_CSUM (1) Guest handles packets with partial checksum (2) If the VIRTIO_NET_F_GUEST_CSUM feature was negotiated, the VIRTIO_NET_HDR_F_NEEDS_CSUM bit in the =10=1Dags=11 =1Celd may be set: if so, the checksum on the packet is incomplete and the =10csum_start= =11 and =10csum_o=1Bset=11 =1Celds indicate how to calculate it (see 1). (3) The converse features are also available: a driver can save the virtual= device some work by negotiating these features.8 The VIRTIO_NET_F_GUEST_CSUM feature indicates that partially checksummed packets can be received, and if it can do that then the VIRTIO_NET_F_GUEST_TSO4, VIRTIO_ NET_F_GUEST_TSO6, VIRTIO_NET_F_GUEST_UFO and VIRTIO_NET_F_GUEST_ECN are the input equivalents of the features described above. See =10Receiving Packets=11 below.