From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] xen: netfront: handle incoming GSO SKBs which are not CHECKSUM_PARTIAL Date: Thu, 27 Jan 2011 14:23:48 -0800 (PST) Message-ID: <20110127.142348.39184559.davem@davemloft.net> References: <1296042981.14780.6813.camel@zakaz.uk.xensource.com> <1296137643-24814-1-git-send-email-ian.campbell@citrix.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, jeremy@goop.org, xen-devel@lists.xensource.com To: ian.campbell@citrix.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:56484 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753447Ab1A0WXN (ORCPT ); Thu, 27 Jan 2011 17:23:13 -0500 In-Reply-To: <1296137643-24814-1-git-send-email-ian.campbell@citrix.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Ian Campbell Date: Thu, 27 Jan 2011 14:14:03 +0000 > The Linux network stack expects all GSO SKBs to have ip_summed == > CHECKSUM_PARTIAL (which implies that the frame contains a partial > checksum) and the Xen network ring protocol similarly expects an SKB > which has GSO set to also have NETRX_csum_blank (which also implies a > partial checksum). > > However there have been cases of buggy guests which mark a frame as > GSO but do not set csum_blank. If we detect that we a receiving such a > frame (which manifests as ip_summed != PARTIAL && skb_is_gso) then > force the SKB to partial and recalculate the checksum, since we cannot > rely on the peer having done so if they have not set csum_blank. > > Add an ethtool stat to track occurances of this event. > > Signed-off-by: Ian Campbell Looks great, applied, thanks Ian.