From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <stephen@networkplumber.org> Received: from mail-pf0-f182.google.com (mail-pf0-f182.google.com [209.85.192.182]) by dpdk.org (Postfix) with ESMTP id 3868C7D4A for <dev@dpdk.org>; Wed, 23 Aug 2017 17:31:47 +0200 (CEST) Received: by mail-pf0-f182.google.com with SMTP id k3so1524012pfc.0 for <dev@dpdk.org>; Wed, 23 Aug 2017 08:31:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=RVDuS5lpS2FIIvn2l+4ExOl/CypaDeYpMMzBw4ce3fw=; b=cwpTZJ8YODS90KjlJ+FqJuKpcdyli5oavf/nMHSbvBzHcepkgxihnksoe4wOuhIiP+ OKkLKDBh8oUdioth9Dn0Bz/l0P3g+0DG40egw61dyd9Q5f/ExLfP4bGvzWsH9xIN3917 0/YrCIaSokR5ZSwNkFDemrYyX5mz9QKlRHkoTOiY0ztYs+Y8RI/eDyp48cieE+bhdu+b 6G+FFWvdZZSBEtsbMjutZvpsP0L9w6M4MYsnqBBdshur1Sgp53WwTkqaIPtlNwqVABLu LpiXZjQt7o/Je5nKoF2Pei+kyRbfpS5OkaKpk0l7bqWG+Zy2UdAi2COrP46THKgV9+zl plNg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=RVDuS5lpS2FIIvn2l+4ExOl/CypaDeYpMMzBw4ce3fw=; b=LuSZixk3UX9RF/sQGKriM5klHw1yOxFIOIr05WUsdgaDwCMuhpkDHwrhMCSaeFQtb1 glnZV62IzQhmxzy1ldqhlSJOTebTITkDJ9Kk6e/HzKsIqWr8hprH7ITErF0JqRzsiAOQ tM02qqHwIs8l/ZzxAqmMWtxnhexq1tqge+j9k6OhUh5IK1+4T7Dt1IL6iPzBhL2vxY1E YSmDoCcvqxnVy2b3iyU9iTaRchRUzaFS62Ey47txkLrphZHrpH3MYu3MbRN8wlnjtIcj hSfQmw+chkGMrE8Dqv+1YtB+wY799ExaKz0fGWxXsJKNdYYGJlEYqKHFBrc5IcEpIZtv aHuw== X-Gm-Message-State: AHYfb5hKvB9iiWQQ+cI091a7WiGGCd9GEX87TYmhlp3ZFOUXDMt0oeXe VfI5B0FDbr6etA3+ X-Received: by 10.84.233.204 with SMTP id m12mr3429688pln.72.1503502306325; Wed, 23 Aug 2017 08:31:46 -0700 (PDT) Received: from xeon-e3 (76-14-207-240.or.wavecable.com. [76.14.207.240]) by smtp.gmail.com with ESMTPSA id t18sm3856363pfj.9.2017.08.23.08.31.45 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 23 Aug 2017 08:31:45 -0700 (PDT) Date: Wed, 23 Aug 2017 08:31:35 -0700 From: Stephen Hemminger <stephen@networkplumber.org> To: Olivier MATZ <olivier.matz@6wind.com> Cc: Yuanhan Liu <yliu@fridaylinux.org>, maxime.coquelin@redhat.com, dev@dpdk.org, stable@dpdk.org Message-ID: <20170823083135.67193f91@xeon-e3> In-Reply-To: <20170823093025.bhjwbygfyz4ifd6r@glumotte.dev.6wind.com> References: <20170707195250.22259-1-stephen@networkplumber.org> <20170708031222.GA11626@yliu-home> <20170823093025.bhjwbygfyz4ifd6r@glumotte.dev.6wind.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH 0/2] virtio fix false offload claims X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <http://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <http://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Wed, 23 Aug 2017 15:31:47 -0000 On Wed, 23 Aug 2017 11:30:26 +0200 Olivier MATZ <olivier.matz@6wind.com> wrote: > Hello, > > On Sat, Jul 08, 2017 at 11:12:22AM +0800, Yuanhan Liu wrote: > > On Fri, Jul 07, 2017 at 12:52:48PM -0700, Stephen Hemminger wrote: > > > While doing code for Hyper-V, noticed that the virtio driver was > > > confused about receive versus transmit offloads. The virtio > > > checksum offload is L4 (TCP/UDP) only, not IPv4. Also, TSO > > > and LRO are not the same. > > > > > > This may break some program that was assuming it was getting offloads > > > that it wasn't. > > > > Applied to dpdk-next-virtio. > > > > And I think they should be backported to stable releases, thus, > > > > Cc: stable@dpdk.org > > > > Thanks. > > > > --yliu > > > > > > Stephen Hemminger (2): > > > virtio: don't falsely claim to do IP checksum > > > virtio: don't claim to support LRO > > > > > > drivers/net/virtio/virtio_ethdev.c | 30 +++++------------------------- > > > 1 file changed, 5 insertions(+), 25 deletions(-) > > > > > > -- > > > 2.11.0 > > I think these 2 commits break the virtio offload, which can be tested as > described in this test plan: > http://dpdk.org/ml/archives/dev/2016-October/048092.html > > First, about checksum: the description of rxmode->hw_ip_checksum is: > > hw_ip_checksum : 1, /**< IP/UDP/TCP checksum offload enable. */ > > So, while I agree the name is not well chosen, it is valid to set it > for virtio to enable L4 checksum. > > Then about LRO: setting rxmode->enable_lro is a way to tell the host that the > guest is ok to receive tso packets. From the guest point of view, it is like > enabling lro on a physical driver. Again, it is valid and useful to do this. > > Before removing these features, it would have been nice to have a quick look at > the commits that introduced them. I am ok with keeping LRO as long as the documentation changed. And virtio driver did some enforcement. For checksums, the hw_ip_checksum flag either needs to be more fine grain (IP, UDP, TCP) which would be best, or virtio would have to check IP checksum in software.