On Fri, 28 Jun 2024 10:19:44 +0800, Jason Wang <jasowang@xxxxxxxxxx> wrote:
> On Tue, Jun 18, 2024 at 3:57 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote:
> >
> > Support AF-XDP for merge mode.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> > ---
> > drivers/net/virtio_net.c | 139 +++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 139 insertions(+)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 06608d696e2e..cfa106aa8039 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -504,6 +504,10 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
> > struct net_device *dev,
> > unsigned int *xdp_xmit,
> > struct virtnet_rq_stats *stats);
> > +static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb,
> > + struct sk_buff *curr_skb,
> > + struct page *page, void *buf,
> > + int len, int truesize);
> >
> > static bool is_xdp_frame(void *ptr)
> > {
> > @@ -1128,6 +1132,139 @@ static struct sk_buff *virtnet_receive_xsk_small(struct net_device *dev, struct
> > }
> > }
> >
> > +static void xsk_drop_follow_bufs(struct net_device *dev,
> > + struct receive_queue *rq,
> > + u32 num_buf,
> > + struct virtnet_rq_stats *stats)
> > +{
> > + struct xdp_buff *xdp;
> > + u32 len;
> > +
> > + while (num_buf-- > 1) {
> > + xdp = virtqueue_get_buf(rq->vq, &len);
> > + if (unlikely(!xdp)) {
> > + pr_debug("%s: rx error: %d buffers missing\n",
> > + dev->name, num_buf);
> > + DEV_STATS_INC(dev, rx_length_errors);
> > + break;
> > + }
> > + u64_stats_add(&stats->bytes, len);
> > + xsk_buff_free(xdp);
> > + }
> > +}
> > +
> > +static int xsk_append_merge_buffer(struct virtnet_info *vi,
> > + struct receive_queue *rq,
> > + struct sk_buff *head_skb,
> > + u32 num_buf,
> > + struct virtio_net_hdr_mrg_rxbuf *hdr,
> > + struct virtnet_rq_stats *stats)
> > +{
> > + struct sk_buff *curr_skb;
> > + struct xdp_buff *xdp;
> > + u32 len, truesize;
> > + struct page *page;
> > + void *buf;
> > +
> > + curr_skb = head_skb;
> > +
> > + while (--num_buf) {
> > + buf = virtqueue_get_buf(rq->vq, &len);
> > + if (unlikely(!buf)) {
> > + pr_debug("%s: rx error: %d buffers out of %d missing\n",
> > + vi->dev->name, num_buf,
> > + virtio16_to_cpu(vi->vdev,
> > + hdr->num_buffers));
> > + DEV_STATS_INC(vi->dev, rx_length_errors);
> > + return -EINVAL;
> > + }
> > +
> > + u64_stats_add(&stats->bytes, len);
> > +
> > + xdp = buf_to_xdp(vi, rq, buf, len);
> > + if (!xdp)
> > + goto err;
> > +
> > + buf = napi_alloc_frag(len);
>
> So we don't do this for non xsk paths. Any reason we can't reuse the
> existing codes?
Do you mean this code:
while (--num_buf) {
int num_skb_frags;
-> buf = virtnet_rq_get_buf(rq, &len, &ctx);
if (unlikely(!buf)) {
pr_debug("%s: rx error: %d buffers out of %d missing\n",
dev->name, num_buf,
virtio16_to_cpu(vi->vdev,
hdr->num_buffers));
DEV_STATS_INC(dev, rx_length_errors);
goto err_buf;
}
u64_stats_add(&stats->bytes, len);
page = virt_to_head_page(buf);
-> truesize = mergeable_ctx_to_truesize(ctx);
-> headroom = mergeable_ctx_to_headroom(ctx);
-> tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
-> room = SKB_DATA_ALIGN(headroom + tailroom);
-> if (unlikely(len > truesize - room)) {
-> pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
-> dev->name, len, (unsigned long)(truesize - room));
-> DEV_STATS_INC(dev, rx_length_errors);
-> goto err_skb;
-> }
curr_skb = virtnet_skb_append_frag(head_skb, curr_skb, page,
buf, len, truesize);
if (!curr_skb)
goto err_skb;
}
The code lines that are marked are differ.
The same logic is separated to function virtnet_skb_append_frag().
So the code is similitude, but we can not merge them.
Thanks.
>
> Thanks
>
