From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH] Request for comments on ixgbe TSO support Date: Fri, 4 Oct 2013 14:19:02 -0700 Message-ID: <20131004141902.710a3f8d@nehalam.linuxnetplumber.net> References: <1380906413-3406-1-git-send-email-jigsaw@gmail.com> <20131004104030.206356dd@nehalam.linuxnetplumber.net> <20131004112302.50693f04@nehalam.linuxnetplumber.net> <1FD9B82B8BF2CF418D9A1000154491D973F58EE2@ORSMSX102.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: "dev-VfR2kkLFssw@public.gmane.org" To: jigsaw Return-path: In-Reply-To: List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" On Fri, 4 Oct 2013 22:10:33 +0300 jigsaw wrote: > Hi Stephen, > > Thanks for showing a bigger picture. > > GSO is quite big implementation, that I think it won't be easily > ported to DPDK. The mbuf needs to be equipped with many fields from > skb to be able to deal with GSO. > Do you have the plan to port GSO to DPDK, or you would like to keep > GSO in scope of virtio? > > Regarding checksum flags, actually I was also thinking of extending > ol_flags but then I gave it up coz I was worried about the size of > mbuf. > My current patch has to push some work to user, due to the fact that > mbuf delivers too few info (such as L2 and L3 protocol details). > > Besides, as you mentioned, the ixgbe driver doesn't leverage the > hardware receive checksum offloading at all. And if this is to be > supported, the checksum flag need further extension. > (On the other hand, TSO doesn't care about receive checksum offloading). > Again, do you have plans to extend cksum flags so that virio feels > more comfortable with DPDK? > > Hi Venky, > > I can either make the commit now as is, or wait till the cksum flags > extension is in place. If Stephen (or somebody else) has the plan for > better support for cksum offloading or GSO, it is perhaps better to > implement TSO on top of that. > > BTW, I have another small question. Current TSO patch offloads the > TCP/IP pseudo cksum work to user. Do you think DPDK could provide some > utility functions for TCP/IPv4/IPv6 pseudo cksum calculation and > updating? > > thx & > rgds, > -Qinglai I want to get Tx checksum offload in virtio working first. Just looking ahead to Rx.