From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jesper Dangaard Brouer , Pavel Popa , David Ahern , Jason Wang , "David S. Miller" Subject: [PATCH 4.14 061/146] virtio-net: disable guest csum during XDP set Date: Tue, 4 Dec 2018 11:49:07 +0100 Message-Id: <20181204103729.293745783@linuxfoundation.org> In-Reply-To: <20181204103726.750894136@linuxfoundation.org> References: <20181204103726.750894136@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang [ Upstream commit e59ff2c49ae16e1d179de679aca81405829aee6c ] We don't disable VIRTIO_NET_F_GUEST_CSUM if XDP was set. This means we can receive partial csumed packets with metadata kept in the vnet_hdr. This may have several side effects: - It could be overridden by header adjustment, thus is might be not correct after XDP processing. - There's no way to pass such metadata information through XDP_REDIRECT to another driver. - XDP does not support checksum offload right now. So simply disable guest csum if possible in this the case of XDP. Fixes: 3f93522ffab2d ("virtio-net: switch off offloads on demand if possible on XDP set") Reported-by: Jesper Dangaard Brouer Cc: Jesper Dangaard Brouer Cc: Pavel Popa Cc: David Ahern Signed-off-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/virtio_net.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -61,7 +61,8 @@ static const unsigned long guest_offload VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, VIRTIO_NET_F_GUEST_ECN, - VIRTIO_NET_F_GUEST_UFO + VIRTIO_NET_F_GUEST_UFO, + VIRTIO_NET_F_GUEST_CSUM }; struct virtnet_stats { @@ -1939,9 +1940,6 @@ static int virtnet_clear_guest_offloads( if (!vi->guest_offloads) return 0; - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM)) - offloads = 1ULL << VIRTIO_NET_F_GUEST_CSUM; - return virtnet_set_guest_offloads(vi, offloads); } @@ -1951,8 +1949,6 @@ static int virtnet_restore_guest_offload if (!vi->guest_offloads) return 0; - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM)) - offloads |= 1ULL << VIRTIO_NET_F_GUEST_CSUM; return virtnet_set_guest_offloads(vi, offloads); }