From patchwork Wed Aug 11 08:16:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 495622 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=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS autolearn=unavailable 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 CCD2DC4320A for ; Wed, 11 Aug 2021 08:16:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB3EB60F38 for ; Wed, 11 Aug 2021 08:16:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235935AbhHKIRG (ORCPT ); Wed, 11 Aug 2021 04:17:06 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:49215 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232489AbhHKIRF (ORCPT ); Wed, 11 Aug 2021 04:17:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628669801; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=zI0/uAuYDFBcIURwjRZoalT1u5FlB/tQ3FmUvIqhq04=; b=H8AC18OwRBQ6WFRZK1xK3LUhPLzAcePvevC+QFzUaV/OxmCVhd6R7BIlsnrIVy6Da5mKk6 Ke48lmPSGnGJOVadFfKMyZEWyUVCoLyO9VcHExNTrUHTE8lcaWbzaNCNbnR9gi5ilLBrkS xoX0QRQAYLx7QbMYQ8HCaKaMkfnNMig= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-286-D5vahKqcM-u3TUMOAR0Wfg-1; Wed, 11 Aug 2021 04:16:38 -0400 X-MC-Unique: D5vahKqcM-u3TUMOAR0Wfg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 46449DF8A5; Wed, 11 Aug 2021 08:16:37 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-243.pek2.redhat.com [10.72.13.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id 09A295C23A; Wed, 11 Aug 2021 08:16:29 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Cc: davem@davemloft.net, kuba@kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ivan@prestigetransportation.com, xiangxia.m.yue@gmail.com, willemb@google.com, edumazet@google.com Subject: [RFC PATCH] virtio-net: use NETIF_F_GRO_HW instead of NETIF_F_LRO Date: Wed, 11 Aug 2021 16:16:23 +0800 Message-Id: <20210811081623.9832-1-jasowang@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Commit a02e8964eaf92 ("virtio-net: ethtool configurable LRO") tries to advertise LRO on behalf of the guest offloading features and allow the administrator to enable and disable those features via ethtool. This may lead several issues: - For the device that doesn't support control guest offloads, the "LRO" can't be disabled so we will get a warn in the dev_disable_lro() - For the device that have the control guest offloads, the guest offloads were disabled in the case of bridge etc which may slow down the traffic. Try to fix this by using NETIF_F_GRO_HW instead so we're not guaranteed to be re-segmented as original. Or we may want a new netdev feature like RX_GSO since the guest offloads for virtio-net is actually to receive GSO packet. Or we can try not advertise LRO is control guest offloads is not enabled. This solves the warning but will still slow down the traffic. Signed-off-by: Jason Wang Tested-by: ivan --- drivers/net/virtio_net.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 0416a7e00914..10c382b08bce 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -63,7 +63,7 @@ static const unsigned long guest_offloads[] = { VIRTIO_NET_F_GUEST_CSUM }; -#define GUEST_OFFLOAD_LRO_MASK ((1ULL << VIRTIO_NET_F_GUEST_TSO4) | \ +#define GUEST_OFFLOAD_GRO_HW_MASK ((1ULL << VIRTIO_NET_F_GUEST_TSO4) | \ (1ULL << VIRTIO_NET_F_GUEST_TSO6) | \ (1ULL << VIRTIO_NET_F_GUEST_ECN) | \ (1ULL << VIRTIO_NET_F_GUEST_UFO)) @@ -2481,7 +2481,7 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog, virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) || virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) || virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) { - NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO/CSUM, disable LRO/CSUM first"); + NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing GRO_HW/CSUM, disable GRO_HW/CSUM first"); return -EOPNOTSUPP; } @@ -2612,15 +2612,15 @@ static int virtnet_set_features(struct net_device *dev, u64 offloads; int err; - if ((dev->features ^ features) & NETIF_F_LRO) { + if ((dev->features ^ features) & NETIF_F_GRO_HW) { if (vi->xdp_enabled) return -EBUSY; - if (features & NETIF_F_LRO) + if (features & NETIF_F_GRO_HW) offloads = vi->guest_offloads_capable; else offloads = vi->guest_offloads_capable & - ~GUEST_OFFLOAD_LRO_MASK; + ~GUEST_OFFLOAD_GRO_HW_MASK; err = virtnet_set_guest_offloads(vi, offloads); if (err) @@ -3100,9 +3100,9 @@ static int virtnet_probe(struct virtio_device *vdev) dev->features |= NETIF_F_RXCSUM; if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)) - dev->features |= NETIF_F_LRO; + dev->features |= NETIF_F_GRO_HW; if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) - dev->hw_features |= NETIF_F_LRO; + dev->hw_features |= NETIF_F_GRO_HW; dev->vlan_features = dev->features;