[RFC PATCH 4/9] virtio_net: remove xdp related info from page_to_skb()

Heng Qi
2022-11-22T07:44:06Z

For the clear construction of multi-buffer xdp_buff, we now remove the xdp
processing interleaved with page_to_skb() before, and the logic of xdp and
building skb from xdp will be separate and independent.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/net/virtio_net.c | 41 +++++++++-------------------------------
1 file changed, 9 insertions(+), 32 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d3e8c63b9c4b..cd65f85d5075 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -439,9 +439,7 @@ static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
static struct sk_buff *page_to_skb(struct virtnet_info *vi,
struct receive_queue *rq,
struct page *page, unsigned int offset,
- unsigned int len, unsigned int truesize,
- bool hdr_valid, unsigned int metasize,
- unsigned int headroom)
+ unsigned int len, unsigned int truesize)
{
struct sk_buff *skb;
struct virtio_net_hdr_mrg_rxbuf *hdr;
@@ -459,21 +457,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
else
hdr_padded_len = sizeof(struct padded_vnet_hdr);

- /* If headroom is not 0, there is an offset between the beginning of the
- * data and the allocated space, otherwise the data and the allocated
- * space are aligned.
- *
- * Buffers with headroom use PAGE_SIZE as alloc size, see
- * add_recvbuf_mergeable() + get_mergeable_buf_len()
- */
- truesize = headroom ? PAGE_SIZE : truesize;
- tailroom = truesize - headroom;
- buf = p - headroom;
-
+ buf = p;
len -= hdr_len;
offset += hdr_padded_len;
p += hdr_padded_len;
- tailroom -= hdr_padded_len + len;
+ tailroom = truesize - hdr_padded_len - len;

shinfo_size = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));

@@ -503,7 +491,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
if (len <= skb_tailroom(skb))
copy = len;
else
- copy = ETH_HLEN + metasize;
+ copy = ETH_HLEN;
skb_put_data(skb, p, copy);

len -= copy;
@@ -542,19 +530,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
give_pages(rq, page);

ok:
- /* hdr_valid means no XDP, so we can copy the vnet header */
- if (hdr_valid) {
- hdr = skb_vnet_hdr(skb);
- memcpy(hdr, hdr_p, hdr_len);
- }
+ hdr = skb_vnet_hdr(skb);
+ memcpy(hdr, hdr_p, hdr_len);
if (page_to_free)
put_page(page_to_free);

- if (metasize) {
- __skb_pull(skb, metasize);
- skb_metadata_set(skb, metasize);
- }
-
return skb;
}

@@ -917,7 +897,7 @@ static struct sk_buff *receive_big(struct net_device *dev,
{
struct page *page = buf;
struct sk_buff *skb =
- page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0, 0);
+ page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);

stats->bytes += len - vi->hdr_len;
if (unlikely(!skb))
@@ -1060,9 +1040,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
rcu_read_unlock();
put_page(page);
head_skb = page_to_skb(vi, rq, xdp_page, offset,
- len, PAGE_SIZE, false,
- metasize,
- headroom);
+ len, PAGE_SIZE);
return head_skb;
}
break;
@@ -1116,8 +1094,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
rcu_read_unlock();

skip_xdp:
- head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
- metasize, headroom);
+ head_skb = page_to_skb(vi, rq, page, offset, len, truesize);
curr_skb = head_skb;

if (unlikely(!curr_skb))
--
2.19.1.6.gb485710b