From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [PATCH net 7/9] virtio-net: forbid XDP when VIRTIO_NET_F_GUEST_UFO is support Date: Fri, 23 Dec 2016 08:10:06 -0800 Message-ID: <585D4C5E.5050908@gmail.com> References: <1482503852-12438-1-git-send-email-jasowang@redhat.com> <1482503852-12438-8-git-send-email-jasowang@redhat.com> <585D4AAD.4030702@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: john.r.fastabend@intel.com To: Jason Wang , mst@redhat.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <585D4AAD.4030702@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org On 16-12-23 08:02 AM, John Fastabend wrote: > On 16-12-23 06:37 AM, Jason Wang wrote: >> When VIRTIO_NET_F_GUEST_UFO is negotiated, host could still send UFO >> packet that exceeds a single page which could not be handled >> correctly by XDP. So this patch forbids setting XDP when GUEST_UFO is >> supported. While at it, forbid XDP for ECN (which comes only from GRO) >> too to prevent user from misconfiguration. >> Is sending packets greater than single page though normal in this case? I don't have any need to support big packet mode other than MST asked for it. And I wasn't seeing this in my tests. MTU is capped at 4k - hdr when XDP is enabled. .John >> Cc: John Fastabend >> Signed-off-by: Jason Wang >> --- >> drivers/net/virtio_net.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index 77ae358..c1f66d8 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c >> @@ -1684,7 +1684,9 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog) >> int i, err; >> >> if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) || >> - virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6)) { >> + virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) || >> + virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) || >> + virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO)) { >> netdev_warn(dev, "can't set XDP while host is implementing LRO, disable LRO first\n"); >> return -EOPNOTSUPP; >> } >> > > Acked-by: John Fastabend >