>> This adds XDP meta data support to the code path receive_small().
>>
>> mrg_rxbuf=off is required on qemu, because receive_mergeable() still
>> doesn't support XDP meta data.
>
>
>What's the reason for this?
I didn't have enough time to add support XDP meta data to
receive_mergeable(). But I'll try it a little more. Please wait for the
next patch.
>>
>> Fixes: de8f3a83b0a0 ("bpf: add meta pointer for direct access")
>> Signed-off-by: Yuya Kusakabe <yuya.kusak...@gmail.com>
>
>
>Could you please cc virtio maintainer through get_maintainer.pl?
>
>Thanks
Sorry. I added them.
Thanks.
> ---
> drivers/net/virtio_net.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 4f3de0ac8b0b..14165c5edb7d 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -644,6 +644,7 @@ static struct sk_buff *receive_small(struct net_device
> *dev,
> unsigned int delta = 0;
> struct page *xdp_page;
> int err;
> + unsigned int metasize = 0;
>
> len -= vi->hdr_len;
> stats->bytes += len;
> @@ -683,8 +684,8 @@ static struct sk_buff *receive_small(struct net_device
> *dev,
>
> xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
> xdp.data = xdp.data_hard_start + xdp_headroom;
> - xdp_set_data_meta_invalid(&xdp);
> xdp.data_end = xdp.data + len;
> + xdp.data_meta = xdp.data;
> xdp.rxq = &rq->xdp_rxq;
> orig_data = xdp.data;
> act = bpf_prog_run_xdp(xdp_prog, &xdp);
> @@ -695,9 +696,11 @@ static struct sk_buff *receive_small(struct net_device
> *dev,
> /* Recalculate length in case bpf program changed it */
> delta = orig_data - xdp.data;
> len = xdp.data_end - xdp.data;
> + metasize = xdp.data - xdp.data_meta;
> break;
> case XDP_TX:
> stats->xdp_tx++;
> + xdp.data_meta = xdp.data;
> xdpf = convert_to_xdp_frame(&xdp);
> if (unlikely(!xdpf))
> goto err_xdp;
> @@ -735,11 +738,14 @@ static struct sk_buff *receive_small(struct net_device
> *dev,
> }
> skb_reserve(skb, headroom - delta);
> skb_put(skb, len);
> - if (!delta) {
> + if (!delta && !metasize) {
> buf += header_offset;
> memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
> } /* keep zeroed vnet hdr since packet was changed by bpf */
>
> + if (metasize)
> + skb_metadata_set(skb, metasize);
> +
> err:
> return skb;
>
