diff mbox series

[net] xdp, net: fix for construct skb by xdp inside xsk zc rx

Message ID 20210615033719.72294-1-xuanzhuo@linux.alibaba.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series [net] xdp, net: fix for construct skb by xdp inside xsk zc rx | expand

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Context Check Description
netdev/apply fail Patch does not apply to net
netdev/tree_selection success Clearly marked for net

Commit Message

Xuan Zhuo June 15, 2021, 3:37 a.m. UTC 
When each driver supports xsk rx, if the received buff returns XDP_PASS
after run xdp prog, it must construct skb based on xdp. This patch
extracts this logic into a public function xdp_construct_skb().

There is a bug in the original logic. When constructing skb, we should
copy the meta information to skb and then use __skb_pull() to correct
the data.

Fixes: 0a714186d3c0f ("i40e: add AF_XDP zero-copy Rx support")
Fixes: 2d4238f556972 ("ice: Add support for AF_XDP")
Fixes: bba2556efad66 ("net: stmmac: Enable RX via AF_XDP zero-copy")
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---

This patch depends on the previous patch:
    [PATCH net] ixgbe: xsk: fix for metasize when construct skb by xdp_buff

 drivers/net/ethernet/intel/i40e/i40e_xsk.c    | 16 +---------
 drivers/net/ethernet/intel/ice/ice_xsk.c      | 12 +-------
 drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c  | 14 +--------
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 23 +-------------
 include/net/xdp.h                             | 30 +++++++++++++++++++
 5 files changed, 34 insertions(+), 61 deletions(-)

--
2.31.0

Comments

Fijalkowski, Maciej June 17, 2021, 1:09 p.m. UTC | #1 
On Tue, Jun 15, 2021 at 11:37:19AM +0800, Xuan Zhuo wrote:
> When each driver supports xsk rx, if the received buff returns XDP_PASS
> after run xdp prog, it must construct skb based on xdp. This patch
> extracts this logic into a public function xdp_construct_skb().
> 
> There is a bug in the original logic. When constructing skb, we should
> copy the meta information to skb and then use __skb_pull() to correct
> the data.
> 
> Fixes: 0a714186d3c0f ("i40e: add AF_XDP zero-copy Rx support")
> Fixes: 2d4238f556972 ("ice: Add support for AF_XDP")
> Fixes: bba2556efad66 ("net: stmmac: Enable RX via AF_XDP zero-copy")
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
> 
> This patch depends on the previous patch:
>     [PATCH net] ixgbe: xsk: fix for metasize when construct skb by xdp_buff

That doesn't make much sense if you ask me, I'd rather squash the patch
mentioned above to this one.

Also, I wanted to introduce such function to the kernel for a long time
but I always head in the back of my head mlx5's AF_XDP ZC implementation
which I'm not sure if it can adjust to something like Intel drivers are
doing.

Maxim? :)

> 
>  drivers/net/ethernet/intel/i40e/i40e_xsk.c    | 16 +---------
>  drivers/net/ethernet/intel/ice/ice_xsk.c      | 12 +-------
>  drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c  | 14 +--------
>  .../net/ethernet/stmicro/stmmac/stmmac_main.c | 23 +-------------
>  include/net/xdp.h                             | 30 +++++++++++++++++++
>  5 files changed, 34 insertions(+), 61 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
> index 68f177a86403..81b0f44eedda 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
> @@ -246,23 +246,9 @@ bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
>  static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
>  					     struct xdp_buff *xdp)
>  {
> -	unsigned int metasize = xdp->data - xdp->data_meta;
> -	unsigned int datasize = xdp->data_end - xdp->data;
>  	struct sk_buff *skb;
> 
> -	/* allocate a skb to store the frags */
> -	skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
> -			       xdp->data_end - xdp->data_hard_start,
> -			       GFP_ATOMIC | __GFP_NOWARN);
> -	if (unlikely(!skb))
> -		goto out;
> -
> -	skb_reserve(skb, xdp->data - xdp->data_hard_start);
> -	memcpy(__skb_put(skb, datasize), xdp->data, datasize);
> -	if (metasize)
> -		skb_metadata_set(skb, metasize);
> -
> -out:
> +	skb = xdp_construct_skb(xdp, &rx_ring->q_vector->napi);
>  	xsk_buff_free(xdp);
>  	return skb;
>  }
> diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
> index a1f89ea3c2bd..f95e1adcebda 100644
> --- a/drivers/net/ethernet/intel/ice/ice_xsk.c
> +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
> @@ -430,22 +430,12 @@ static void ice_bump_ntc(struct ice_ring *rx_ring)
>  static struct sk_buff *
>  ice_construct_skb_zc(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf)
>  {
> -	unsigned int metasize = rx_buf->xdp->data - rx_buf->xdp->data_meta;
> -	unsigned int datasize = rx_buf->xdp->data_end - rx_buf->xdp->data;
> -	unsigned int datasize_hard = rx_buf->xdp->data_end -
> -				     rx_buf->xdp->data_hard_start;
>  	struct sk_buff *skb;
> 
> -	skb = __napi_alloc_skb(&rx_ring->q_vector->napi, datasize_hard,
> -			       GFP_ATOMIC | __GFP_NOWARN);
> +	skb = xdp_construct_skb(rx_buf->xdp, &rx_ring->q_vector->napi);
>  	if (unlikely(!skb))
>  		return NULL;
> 
> -	skb_reserve(skb, rx_buf->xdp->data - rx_buf->xdp->data_hard_start);
> -	memcpy(__skb_put(skb, datasize), rx_buf->xdp->data, datasize);
> -	if (metasize)
> -		skb_metadata_set(skb, metasize);
> -
>  	xsk_buff_free(rx_buf->xdp);
>  	rx_buf->xdp = NULL;
>  	return skb;
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
> index ee88107fa57a..123945832c96 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
> @@ -203,24 +203,12 @@ bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count)
>  static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring,
>  					      struct ixgbe_rx_buffer *bi)
>  {
> -	unsigned int metasize = bi->xdp->data - bi->xdp->data_meta;
> -	unsigned int datasize = bi->xdp->data_end - bi->xdp->data_meta;
>  	struct sk_buff *skb;
> 
> -	/* allocate a skb to store the frags */
> -	skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
> -			       bi->xdp->data_end - bi->xdp->data_hard_start,
> -			       GFP_ATOMIC | __GFP_NOWARN);
> +	skb = xdp_construct_skb(bi->xdp, &rx_ring->q_vector->napi);
>  	if (unlikely(!skb))
>  		return NULL;
> 
> -	skb_reserve(skb, bi->xdp->data_meta - bi->xdp->data_hard_start);
> -	memcpy(__skb_put(skb, datasize), bi->xdp->data_meta, datasize);
> -	if (metasize) {
> -		__skb_pull(skb, metasize);
> -		skb_metadata_set(skb, metasize);
> -	}
> -
>  	xsk_buff_free(bi->xdp);
>  	bi->xdp = NULL;
>  	return skb;
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index c87202cbd3d6..143ac1edb876 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -4729,27 +4729,6 @@ static void stmmac_finalize_xdp_rx(struct stmmac_priv *priv,
>  		xdp_do_flush();
>  }
> 
> -static struct sk_buff *stmmac_construct_skb_zc(struct stmmac_channel *ch,
> -					       struct xdp_buff *xdp)
> -{
> -	unsigned int metasize = xdp->data - xdp->data_meta;
> -	unsigned int datasize = xdp->data_end - xdp->data;
> -	struct sk_buff *skb;
> -
> -	skb = __napi_alloc_skb(&ch->rxtx_napi,
> -			       xdp->data_end - xdp->data_hard_start,
> -			       GFP_ATOMIC | __GFP_NOWARN);
> -	if (unlikely(!skb))
> -		return NULL;
> -
> -	skb_reserve(skb, xdp->data - xdp->data_hard_start);
> -	memcpy(__skb_put(skb, datasize), xdp->data, datasize);
> -	if (metasize)
> -		skb_metadata_set(skb, metasize);
> -
> -	return skb;
> -}
> -
>  static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,
>  				   struct dma_desc *p, struct dma_desc *np,
>  				   struct xdp_buff *xdp)
> @@ -4761,7 +4740,7 @@ static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,
>  	struct sk_buff *skb;
>  	u32 hash;
> 
> -	skb = stmmac_construct_skb_zc(ch, xdp);
> +	skb = xdp_construct_skb(xdp, &ch->rxtx_napi);
>  	if (!skb) {
>  		priv->dev->stats.rx_dropped++;
>  		return;
> diff --git a/include/net/xdp.h b/include/net/xdp.h
> index a5bc214a49d9..561e21eaf718 100644
> --- a/include/net/xdp.h
> +++ b/include/net/xdp.h
> @@ -95,6 +95,36 @@ xdp_prepare_buff(struct xdp_buff *xdp, unsigned char *hard_start,
>  	xdp->data_meta = meta_valid ? data : data + 1;
>  }
> 
> +static __always_inline struct sk_buff *
> +xdp_construct_skb(struct xdp_buff *xdp, struct napi_struct *napi)
> +{
> +	unsigned int metasize;
> +	unsigned int datasize;
> +	unsigned int headroom;
> +	struct sk_buff *skb;
> +	unsigned int len;
> +
> +	/* this include metasize */
> +	datasize = xdp->data_end  - xdp->data_meta;
> +	metasize = xdp->data      - xdp->data_meta;
> +	headroom = xdp->data_meta - xdp->data_hard_start;
> +	len      = xdp->data_end  - xdp->data_hard_start;
> +
> +	/* allocate a skb to store the frags */
> +	skb = __napi_alloc_skb(napi, len, GFP_ATOMIC | __GFP_NOWARN);
> +	if (unlikely(!skb))
> +		return NULL;
> +
> +	skb_reserve(skb, headroom);
> +	memcpy(__skb_put(skb, datasize), xdp->data_meta, datasize);
> +	if (metasize) {
> +		__skb_pull(skb, metasize);
> +		skb_metadata_set(skb, metasize);
> +	}
> +
> +	return skb;
> +}
> +
>  /* Reserve memory area at end-of data area.
>   *
>   * This macro reserves tailroom in the XDP buffer by limiting the
> --
> 2.31.0
>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 68f177a86403..81b0f44eedda 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -246,23 +246,9 @@  bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
 static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
 					     struct xdp_buff *xdp)
 {
-	unsigned int metasize = xdp->data - xdp->data_meta;
-	unsigned int datasize = xdp->data_end - xdp->data;
 	struct sk_buff *skb;

-	/* allocate a skb to store the frags */
-	skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
-			       xdp->data_end - xdp->data_hard_start,
-			       GFP_ATOMIC | __GFP_NOWARN);
-	if (unlikely(!skb))
-		goto out;
-
-	skb_reserve(skb, xdp->data - xdp->data_hard_start);
-	memcpy(__skb_put(skb, datasize), xdp->data, datasize);
-	if (metasize)
-		skb_metadata_set(skb, metasize);
-
-out:
+	skb = xdp_construct_skb(xdp, &rx_ring->q_vector->napi);
 	xsk_buff_free(xdp);
 	return skb;
 }
diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index a1f89ea3c2bd..f95e1adcebda 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -430,22 +430,12 @@  static void ice_bump_ntc(struct ice_ring *rx_ring)
 static struct sk_buff *
 ice_construct_skb_zc(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf)
 {
-	unsigned int metasize = rx_buf->xdp->data - rx_buf->xdp->data_meta;
-	unsigned int datasize = rx_buf->xdp->data_end - rx_buf->xdp->data;
-	unsigned int datasize_hard = rx_buf->xdp->data_end -
-				     rx_buf->xdp->data_hard_start;
 	struct sk_buff *skb;

-	skb = __napi_alloc_skb(&rx_ring->q_vector->napi, datasize_hard,
-			       GFP_ATOMIC | __GFP_NOWARN);
+	skb = xdp_construct_skb(rx_buf->xdp, &rx_ring->q_vector->napi);
 	if (unlikely(!skb))
 		return NULL;

-	skb_reserve(skb, rx_buf->xdp->data - rx_buf->xdp->data_hard_start);
-	memcpy(__skb_put(skb, datasize), rx_buf->xdp->data, datasize);
-	if (metasize)
-		skb_metadata_set(skb, metasize);
-
 	xsk_buff_free(rx_buf->xdp);
 	rx_buf->xdp = NULL;
 	return skb;
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
index ee88107fa57a..123945832c96 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
@@ -203,24 +203,12 @@  bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count)
 static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring,
 					      struct ixgbe_rx_buffer *bi)
 {
-	unsigned int metasize = bi->xdp->data - bi->xdp->data_meta;
-	unsigned int datasize = bi->xdp->data_end - bi->xdp->data_meta;
 	struct sk_buff *skb;

-	/* allocate a skb to store the frags */
-	skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
-			       bi->xdp->data_end - bi->xdp->data_hard_start,
-			       GFP_ATOMIC | __GFP_NOWARN);
+	skb = xdp_construct_skb(bi->xdp, &rx_ring->q_vector->napi);
 	if (unlikely(!skb))
 		return NULL;

-	skb_reserve(skb, bi->xdp->data_meta - bi->xdp->data_hard_start);
-	memcpy(__skb_put(skb, datasize), bi->xdp->data_meta, datasize);
-	if (metasize) {
-		__skb_pull(skb, metasize);
-		skb_metadata_set(skb, metasize);
-	}
-
 	xsk_buff_free(bi->xdp);
 	bi->xdp = NULL;
 	return skb;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c87202cbd3d6..143ac1edb876 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4729,27 +4729,6 @@  static void stmmac_finalize_xdp_rx(struct stmmac_priv *priv,
 		xdp_do_flush();
 }

-static struct sk_buff *stmmac_construct_skb_zc(struct stmmac_channel *ch,
-					       struct xdp_buff *xdp)
-{
-	unsigned int metasize = xdp->data - xdp->data_meta;
-	unsigned int datasize = xdp->data_end - xdp->data;
-	struct sk_buff *skb;
-
-	skb = __napi_alloc_skb(&ch->rxtx_napi,
-			       xdp->data_end - xdp->data_hard_start,
-			       GFP_ATOMIC | __GFP_NOWARN);
-	if (unlikely(!skb))
-		return NULL;
-
-	skb_reserve(skb, xdp->data - xdp->data_hard_start);
-	memcpy(__skb_put(skb, datasize), xdp->data, datasize);
-	if (metasize)
-		skb_metadata_set(skb, metasize);
-
-	return skb;
-}
-
 static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,
 				   struct dma_desc *p, struct dma_desc *np,
 				   struct xdp_buff *xdp)
@@ -4761,7 +4740,7 @@  static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,
 	struct sk_buff *skb;
 	u32 hash;

-	skb = stmmac_construct_skb_zc(ch, xdp);
+	skb = xdp_construct_skb(xdp, &ch->rxtx_napi);
 	if (!skb) {
 		priv->dev->stats.rx_dropped++;
 		return;
diff --git a/include/net/xdp.h b/include/net/xdp.h
index a5bc214a49d9..561e21eaf718 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -95,6 +95,36 @@  xdp_prepare_buff(struct xdp_buff *xdp, unsigned char *hard_start,
 	xdp->data_meta = meta_valid ? data : data + 1;
 }

+static __always_inline struct sk_buff *
+xdp_construct_skb(struct xdp_buff *xdp, struct napi_struct *napi)
+{
+	unsigned int metasize;
+	unsigned int datasize;
+	unsigned int headroom;
+	struct sk_buff *skb;
+	unsigned int len;
+
+	/* this include metasize */
+	datasize = xdp->data_end  - xdp->data_meta;
+	metasize = xdp->data      - xdp->data_meta;
+	headroom = xdp->data_meta - xdp->data_hard_start;
+	len      = xdp->data_end  - xdp->data_hard_start;
+
+	/* allocate a skb to store the frags */
+	skb = __napi_alloc_skb(napi, len, GFP_ATOMIC | __GFP_NOWARN);
+	if (unlikely(!skb))
+		return NULL;
+
+	skb_reserve(skb, headroom);
+	memcpy(__skb_put(skb, datasize), xdp->data_meta, datasize);
+	if (metasize) {
+		__skb_pull(skb, metasize);
+		skb_metadata_set(skb, metasize);
+	}
+
+	return skb;
+}
+
 /* Reserve memory area at end-of data area.
  *
  * This macro reserves tailroom in the XDP buffer by limiting the