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virtio_net: xsk: rx: support recv merge mode

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Support AF-XDP for merge mode.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://patch.msgid.link/20240708112537.96291-11-xuanzhuo@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Xuan Zhuo 2024-07-08 19:25:37 +08:00 committed by Jakub Kicinski
parent a4e7ba7027
commit 99c861b44e
1 changed files with 144 additions and 0 deletions
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144
drivers/net/virtio_net.c
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@ -504,6 +504,10 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
struct virtnet_rq_stats *stats);
static void virtnet_receive_done(struct virtnet_info *vi, struct receive_queue *rq,
struct sk_buff *skb, u8 flags);
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)
{
@ -984,6 +988,11 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
rq = &vi->rq[i];
if (rq->xsk_pool) {
xsk_buff_free((struct xdp_buff *)buf);
return;
}
if (!vi->big_packets || vi->mergeable_rx_bufs)
virtnet_rq_unmap(rq, buf, 0);
@ -1152,6 +1161,139 @@ 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 = xsk_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 void virtnet_receive_xsk_buf(struct virtnet_info *vi, struct receive_queue *rq,
void *buf, u32 len,
unsigned int *xdp_xmit,
@ -1181,6 +1323,8 @@ static void virtnet_receive_xsk_buf(struct virtnet_info *vi, struct receive_queu
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);
if (skb)
virtnet_receive_done(vi, rq, skb, flags);