From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Kicinski Subject: Re: [PATCH net] virtio_net: reject XDP programs using header adjustment Date: Tue, 20 Dec 2016 12:30:39 +0000 Message-ID: References: <20161219150500.2600-1-jakub.kicinski@netronome.com> <58581E01.7070902@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: netdev@vger.kernel.org, kafai@fb.com, Daniel Borkmann , alexei.starovoitov@gmail.com, mst@redhat.com To: John Fastabend Return-path: Received: from mail-qt0-f175.google.com ([209.85.216.175]:35233 "EHLO mail-qt0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757447AbcLTMal (ORCPT ); Tue, 20 Dec 2016 07:30:41 -0500 Received: by mail-qt0-f175.google.com with SMTP id c47so174990694qtc.2 for ; Tue, 20 Dec 2016 04:30:40 -0800 (PST) In-Reply-To: <58581E01.7070902@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Dec 19, 2016 at 5:50 PM, John Fastabend wrote: > On 16-12-19 07:05 AM, Jakub Kicinski wrote: >> commit 17bedab27231 ("bpf: xdp: Allow head adjustment in XDP prog") >> added a new XDP helper to prepend and remove data from a frame. >> Make virtio_net reject programs making use of this helper until >> proper support is added. >> >> Signed-off-by: Jakub Kicinski >> --- >> drivers/net/virtio_net.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index 08327e005ccc..db761f37783e 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c >> @@ -1677,6 +1677,11 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog) >> u16 xdp_qp = 0, curr_qp; >> int i, err; >> >> + if (prog && prog->xdp_adjust_head) { >> + netdev_warn(dev, "Does not support bpf_xdp_adjust_head()\n"); >> + return -EOPNOTSUPP; >> + } >> + >> if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) || >> virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6)) { >> netdev_warn(dev, "can't set XDP while host is implementing LRO, disable LRO first\n"); >> > > Acked-by: John Fastabend > > Thanks patch looks good. Alternatively we could push a "bug fix" to > support the adjust header feature depending on how DaveM and MST feel > about that. I don't have a strong opinion but I have the patch on my > queue it just needs some more testing. Cool! I thought to ask you what your plans are but then this patch is so trivial I decided to just post it :) I'm perfectly happy with dropping it for now and reposting after ~rc5 if needed.