From patchwork Mon Feb 24 10:19:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anton Ivanov X-Patchwork-Id: 1242992 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=cambridgegreys.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48QyjW6LgLz9sPk for ; Mon, 24 Feb 2020 21:19:43 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727277AbgBXKTm (ORCPT ); Mon, 24 Feb 2020 05:19:42 -0500 Received: from ivanoab7.miniserver.com ([37.128.132.42]:48210 "EHLO www.kot-begemot.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726509AbgBXKTm (ORCPT ); Mon, 24 Feb 2020 05:19:42 -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 1j6Aps-0004p1-6Q; Mon, 24 Feb 2020 10:19:38 +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 1j6Api-0003hm-NT; Mon, 24 Feb 2020 10:19:31 +0000 From: anton.ivanov@cambridgegreys.com To: netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-um@lists.infradead.org Cc: mst@redhat.com, jasowang@redhat.com, eric.dumazet@gmail.com, Anton Ivanov Subject: [PATCH v2] virtio: Work around frames incorrectly marked as gso Date: Mon, 24 Feb 2020 10:19:12 +0000 Message-Id: <20200224101912.14074-1-anton.ivanov@cambridgegreys.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-Spam-Score: -1.0 X-Spam-Score: -0.7 X-Clacks-Overhead: GNU Terry Pratchett Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Anton Ivanov Some of the locally generated 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 Reported-by: kbuild test robot Acked-by: Michael S. Tsirkin --- include/linux/virtio_net.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 0d1fe9297ac6..94fb78c3a2ab 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -100,8 +100,8 @@ static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, { memset(hdr, 0, sizeof(*hdr)); /* no info leak */ - if (skb_is_gso(skb)) { - struct skb_shared_info *sinfo = skb_shinfo(skb); + struct skb_shared_info *sinfo = skb_shinfo(skb); + if (skb_is_gso(skb) && sinfo->gso_type) { /* This is a hint as to how much should be linear. */ hdr->hdr_len = __cpu_to_virtio16(little_endian,