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);
+ if (!buf) {
+ xsk_buff_free(xdp);
+ goto err;
+ }
+
+ memcpy(buf, xdp->data - vi->hdr_len, len);
+
+ xsk_buff_free(xdp);
+
+ page = virt_to_page(buf);
+
+ truesize = len;
+
+ curr_skb = virtnet_skb_append_frag(head_skb, curr_skb, page,
+ buf, len, truesize);
+ if (!curr_skb) {
+ put_page(page);
+ goto err;
+ }
+ }
+
+ return 0;
+
+err:
+ xsk_drop_follow_bufs(vi->dev, rq, num_buf, stats);
+ return -EINVAL;
+}
+
+static struct sk_buff *virtnet_receive_xsk_merge(struct net_device *dev, struct virtnet_info *vi,
+ struct receive_queue *rq, struct xdp_buff *xdp,
+ unsigned int *xdp_xmit,
+ struct virtnet_rq_stats *stats)
+{
+ struct virtio_net_hdr_mrg_rxbuf *hdr;
+ struct bpf_prog *prog;
+ struct sk_buff *skb;
+ u32 ret, num_buf;
+
+ hdr = xdp->data - vi->hdr_len;
+ num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
+
+ ret = XDP_PASS;
+ rcu_read_lock();
+ prog = rcu_dereference(rq->xdp_prog);
+ /* TODO: support multi buffer. */
+ if (prog && num_buf == 1)
+ ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit, stats);
+ rcu_read_unlock();
+
+ switch (ret) {
+ case XDP_PASS:
+ skb = xdp_construct_skb(rq, xdp);
+ if (!skb)
+ goto drop_bufs;
+
+ if (xsk_append_merge_buffer(vi, rq, skb, num_buf, hdr, stats)) {
+ dev_kfree_skb(skb);
+ goto drop;
+ }
+
+ return skb;
+
+ case XDP_TX:
+ case XDP_REDIRECT:
+ return NULL;
+
+ default:
+ /* drop packet */
+ xsk_buff_free(xdp);
+ }
+
+drop_bufs:
+ xsk_drop_follow_bufs(dev, rq, num_buf, stats);
+
+drop:
+ u64_stats_inc(&stats->drops);
+ return NULL;
+}
+
static struct sk_buff *virtnet_receive_xsk_buf(struct virtnet_info *vi, struct receive_queue *rq,
void *buf, u32 len,
unsigned int *xdp_xmit,
@@ -1154,6 +1291,8 @@ static struct sk_buff *virtnet_receive_xsk_buf(struct virtnet_info *vi, struct r
if (!vi->mergeable_rx_bufs)
skb = virtnet_receive_xsk_small(dev, vi, rq, xdp, xdp_xmit, stats);
+ else
+ skb = virtnet_receive_xsk_merge(dev, vi, rq, xdp, xdp_xmit, stats);
return skb;
}
--
2.32.0.3.g01195cf9f
