From: "Michael S. Tsirkin" <mst@redhat•com>
To: Yuya Kusakabe <yuya.kusakabe@gmail•com>
Cc: jasowang@redhat•com, andriin@fb•com, ast@kernel•org,
bpf@vger•kernel.org, daniel@iogearbox•net, davem@davemloft•net,
hawk@kernel•org, john.fastabend@gmail•com, kafai@fb•com,
kuba@kernel•org, linux-kernel@vger•kernel.org,
netdev@vger•kernel.org, songliubraving@fb•com, yhs@fb•com
Subject: Re: [PATCH bpf-next v6 1/2] virtio_net: keep vnet header zeroed if XDP is loaded for small buffer
Date: Tue, 25 Feb 2020 06:18:01 -0500 [thread overview]
Message-ID: <20200225061501-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20200225033212.437563-1-yuya.kusakabe@gmail.com>
On Tue, Feb 25, 2020 at 12:32:11PM +0900, Yuya Kusakabe wrote:
> We do not want to care about the vnet header in receive_small() if XDP
> is loaded, since we can not know whether or not the packet is modified
> by XDP.
>
> Fixes: f6b10209b90d ("virtio-net: switch to use build_skb() for small buffer")
> Signed-off-by: Yuya Kusakabe <yuya.kusakabe@gmail•com>
Acked-by: Michael S. Tsirkin <mst@redhat•com>
> ---
> drivers/net/virtio_net.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 2fe7a3188282..f39d0218bdaa 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -735,10 +735,10 @@ static struct sk_buff *receive_small(struct net_device *dev,
> }
> skb_reserve(skb, headroom - delta);
> skb_put(skb, len);
> - if (!delta) {
> + if (!xdp_prog) {
> buf += header_offset;
> memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
> - } /* keep zeroed vnet hdr since packet was changed by bpf */
> + } /* keep zeroed vnet hdr since XDP is loaded */
>
> err:
> return skb;
> --
> 2.24.1
next prev parent reply other threads:[~2020-02-25 11:18 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-25 3:31 [PATCH bpf-next v6 0/2] virtio_net: add XDP meta data support Yuya Kusakabe
2020-02-25 3:32 ` [PATCH bpf-next v6 1/2] virtio_net: keep vnet header zeroed if XDP is loaded for small buffer Yuya Kusakabe
2020-02-25 3:32 ` [PATCH bpf-next v6 2/2] virtio_net: add XDP meta data support Yuya Kusakabe
2020-02-25 5:45 ` Jason Wang
2020-02-25 11:19 ` Michael S. Tsirkin
2020-02-25 5:44 ` [PATCH bpf-next v6 1/2] virtio_net: keep vnet header zeroed if XDP is loaded for small buffer Jason Wang
2020-02-25 11:18 ` Michael S. Tsirkin [this message]
2020-02-25 21:59 ` [PATCH bpf-next v6 0/2] virtio_net: add XDP meta data support Daniel Borkmann
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