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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 0E4F2C352A3 for ; Mon, 10 Feb 2020 16:55:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5B7720661 for ; Mon, 10 Feb 2020 16:55:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727683AbgBJQzx (ORCPT ); Mon, 10 Feb 2020 11:55:53 -0500 Received: from ivanoab7.miniserver.com ([37.128.132.42]:41754 "EHLO www.kot-begemot.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727499AbgBJQzw (ORCPT ); Mon, 10 Feb 2020 11:55:52 -0500 Received: from tun252.jain.kot-begemot.co.uk ([192.168.18.6] helo=jain.kot-begemot.co.uk) by www.kot-begemot.co.uk with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j1CLa-0004sq-Iu; Mon, 10 Feb 2020 16:55:46 +0000 Received: from jain.kot-begemot.co.uk ([192.168.3.3]) by jain.kot-begemot.co.uk with esmtp (Exim 4.92) (envelope-from ) id 1j1CLY-0004P0-4b; Mon, 10 Feb 2020 16:55:46 +0000 Subject: Re: [PATCH] virtio: Work around frames incorrectly marked as gso To: netdev@vger.kernel.org Cc: linux-um@lists.infradead.org, jasowang@redhat.com, mst@redhat.com, virtualization@lists.linux-foundation.org References: <20191209104824.17059-1-anton.ivanov@cambridgegreys.com> From: Anton Ivanov Message-ID: <57230228-7030-c65f-a24f-910ca52bbe9e@cambridgegreys.com> Date: Mon, 10 Feb 2020 16:55:44 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20191209104824.17059-1-anton.ivanov@cambridgegreys.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Clacks-Overhead: GNU Terry Pratchett Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 09/12/2019 10:48, anton.ivanov@cambridgegreys.com wrote: > From: Anton Ivanov > > Some of the frames marked as GSO which arrive at > virtio_net_hdr_from_skb() have no GSO_TYPE, no > fragments (data_len = 0) and length significantly shorter > than the MTU (752 in my experiments). > > This is observed on raw sockets reading off vEth interfaces > in all 4.x and 5.x kernels I tested. > > These frames are reported as invalid while they are in fact > gso-less frames. > > This patch marks the vnet header as no-GSO for them instead > of reporting it as invalid. > > Signed-off-by: Anton Ivanov > --- > include/linux/virtio_net.h | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h > index 0d1fe9297ac6..d90d5cff1b9a 100644 > --- a/include/linux/virtio_net.h > +++ b/include/linux/virtio_net.h > @@ -112,8 +112,12 @@ static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, > hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; > else if (sinfo->gso_type & SKB_GSO_TCPV6) > hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; > - else > - return -EINVAL; > + else { > + if (skb->data_len == 0) > + hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; > + else > + return -EINVAL; > + } > if (sinfo->gso_type & SKB_GSO_TCP_ECN) > hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN; > } else > ping. -- Anton R. Ivanov Cambridgegreys Limited. Registered in England. Company Number 10273661 https://www.cambridgegreys.com/