From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32CAFC64EB4 for ; Sat, 1 Dec 2018 01:25:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EEBC120867 for ; Sat, 1 Dec 2018 01:25:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EEBC120867 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=davemloft.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726850AbeLAMhD (ORCPT ); Sat, 1 Dec 2018 07:37:03 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:37012 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726640AbeLAMhD (ORCPT ); Sat, 1 Dec 2018 07:37:03 -0500 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::bf5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 37F5E14F2407F; Fri, 30 Nov 2018 17:25:47 -0800 (PST) Date: Fri, 30 Nov 2018 17:25:46 -0800 (PST) Message-Id: <20181130.172546.127269245503154590.davem@davemloft.net> To: jasowang@redhat.com Cc: mst@redhat.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] virtio-net: keep vnet header zeroed after processing XDP From: David Miller In-Reply-To: <20181129055316.24090-1-jasowang@redhat.com> References: <20181129055316.24090-1-jasowang@redhat.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Fri, 30 Nov 2018 17:25:47 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jason Wang Date: Thu, 29 Nov 2018 13:53:16 +0800 > We copy vnet header unconditionally in page_to_skb() this is wrong > since XDP may modify the packet data. So let's keep a zeroed vnet > header for not confusing the conversion between vnet header and skb > metadata. > > In the future, we should able to detect whether or not the packet was > modified and keep using the vnet header when packet was not touched. > > Fixes: f600b6905015 ("virtio_net: Add XDP support") > Reported-by: Pavel Popa > Signed-off-by: Jason Wang Applied and queued up for -stable, thanks.