From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH 0/2] fix kernel crash with macvtap on top of LRO Date: Thu, 7 Feb 2013 22:31:35 +0000 Message-ID: <1360276295.3605.44.camel@bwh-desktop.uk.solarflarecom.com> References: <1360193660.32217.39.camel@deadeye.wl.decadent.org.uk> <1360207111.28557.47.camel@edumazet-glaptop> <1360254046.3605.8.camel@bwh-desktop.uk.solarflarecom.com> <20130207.131420.1211188723341167971.davem@davemloft.net> <20130207213315.GB5064@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: e1000-devel@lists.sourceforge.net, netdev@vger.kernel.org, jitendra.kalsaria@qlogic.com, bruce.w.allan@intel.com, jesse.brandeburg@intel.com, eilong@broadcom.com, john.r.fastabend@intel.com, john.ronciak@intel.com, sony.chacko@qlogic.com, linux-driver@qlogic.com, David Miller , linux-kernel@vger.kernel.org, jacob.e.keller@intel.com To: "Michael S. Tsirkin" Return-path: In-Reply-To: <20130207213315.GB5064@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org On Thu, 2013-02-07 at 23:33 +0200, Michael S. Tsirkin wrote: > On Thu, Feb 07, 2013 at 01:14:20PM -0500, David Miller wrote: > > From: Ben Hutchings > > Date: Thu, 7 Feb 2013 16:20:46 +0000 > > > > > If the consensus is still that we must preserve packets exactly (aside > > > from the usual modifications by IP routers) then LRO should be disabled > > > on all devices for which forwarding is enabled. > > > > I believe this is still undoubtedly the consensus. > > But we don't need to preserve the packets when passing them to macvtap > (which discards all this info smashing the packet into a single buffer anyway), > correct? macvtap_skb_to_vnet_hdr() certainly seems to be trying to preserve all the packet information. > If true LRO with macvtap might be useful and so the patchset is probably > still the right thing to do to fix the macvtap crash. Makes sense? If macvtap+virtio_net is expected to re-segment then this is fine. But I don't see why it should be different from other uses of macvlan. > We might want to add code to forward LRO status from macvlan > (not macvtap) back to the lowerdev, so that setting up forwarding > from macvlan disables LRO on the lowerdev, but that seems like another > issue. I think it's the same issue! Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired