[PATCH net-next v2 0/2] xsk: respect the offsets when copying frags

[PATCH net-next v2 0/2] xsk: respect the offsets when copying frags

[Bui Quang Minh]

Hi everyone,

In commit 560d958c6c68 ("xsk: add generic XSk &xdp_buff -> skb
conversion"), we introduce a helper to convert zerocopy xdp_buff to skb.
However, in the frag copy, we mistakenly ignore the frag's offset. This
series adds the missing offset when copying frags in
xdp_copy_frags_from_zc(). This function is not used anywhere so no
backport is needed.

This series also makes xdp_copy_frags_from_zc() use page allocation API
page_pool_dev_alloc() instead of page_pool_dev_alloc_netmem() to avoid
possible confusion of the returned value.

Thanks,
Quang Minh.

Bui Quang Minh (2):
  xsk: respect the offsets when copying frags
  xsk: convert xdp_copy_frags_from_zc() to use page_pool_dev_alloc()

 net/core/xdp.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

-- 
2.43.0

[PATCH net-next v2 1/2] xsk: respect the offsets when copying frags

[Bui Quang Minh]

In commit 560d958c6c68 ("xsk: add generic XSk &xdp_buff -> skb
conversion"), we introduce a helper to convert zerocopy xdp_buff to skb.
However, in the frag copy, we mistakenly ignore the frag's offset. This
commit adds the missing offset when copying frags in
xdp_copy_frags_from_zc(). This function is not used anywhere so no
backport is needed.

Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
---
 net/core/xdp.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/core/xdp.c b/net/core/xdp.c
index ea819764ae39..89111c68e545 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -698,7 +698,8 @@ static noinline bool xdp_copy_frags_from_zc(struct sk_buff *skb,
 	nr_frags = xinfo->nr_frags;
 
 	for (u32 i = 0; i < nr_frags; i++) {
-		u32 len = skb_frag_size(&xinfo->frags[i]);
+		const skb_frag_t *frag = &xinfo->frags[i];
+		u32 len = skb_frag_size(frag);
 		u32 offset, truesize = len;
 		netmem_ref netmem;
 
@@ -708,8 +709,8 @@ static noinline bool xdp_copy_frags_from_zc(struct sk_buff *skb,
 			return false;
 		}
 
-		memcpy(__netmem_address(netmem),
-		       __netmem_address(xinfo->frags[i].netmem),
+		memcpy(__netmem_address(netmem) + offset,
+		       __netmem_address(frag->netmem) + skb_frag_off(frag),
 		       LARGEST_ALIGN(len));
 		__skb_fill_netmem_desc_noacc(sinfo, i, netmem, offset, len);
 
-- 
2.43.0

[PATCH net-next v2 2/2] xsk: convert xdp_copy_frags_from_zc() to use page_pool_dev_alloc()

[Bui Quang Minh]

This commit makes xdp_copy_frags_from_zc() use page allocation API
page_pool_dev_alloc() instead of page_pool_dev_alloc_netmem() to avoid
possible confusion of the returned value.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
---
 net/core/xdp.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/net/core/xdp.c b/net/core/xdp.c
index 89111c68e545..4e91c7790671 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -701,21 +701,21 @@ static noinline bool xdp_copy_frags_from_zc(struct sk_buff *skb,
 		const skb_frag_t *frag = &xinfo->frags[i];
 		u32 len = skb_frag_size(frag);
 		u32 offset, truesize = len;
-		netmem_ref netmem;
+		struct page *page;
 
-		netmem = page_pool_dev_alloc_netmem(pp, &offset, &truesize);
-		if (unlikely(!netmem)) {
+		page = page_pool_dev_alloc(pp, &offset, &truesize);
+		if (unlikely(!page)) {
 			sinfo->nr_frags = i;
 			return false;
 		}
 
-		memcpy(__netmem_address(netmem) + offset,
-		       __netmem_address(frag->netmem) + skb_frag_off(frag),
+		memcpy(page_address(page) + offset,
+		       skb_frag_page(frag) + skb_frag_off(frag),
 		       LARGEST_ALIGN(len));
-		__skb_fill_netmem_desc_noacc(sinfo, i, netmem, offset, len);
+		__skb_fill_page_desc_noacc(sinfo, i, page, offset, len);
 
 		tsize += truesize;
-		pfmemalloc |= netmem_is_pfmemalloc(netmem);
+		pfmemalloc |= page_is_pfmemalloc(page);
 	}
 
 	xdp_update_skb_shared_info(skb, nr_frags, xinfo->xdp_frags_size,
-- 
2.43.0

Re: [PATCH net-next v2 0/2] xsk: respect the offsets when copying frags

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Sat, 26 Apr 2025 15:12:18 +0700 you wrote:
> Hi everyone,
> 
> In commit 560d958c6c68 ("xsk: add generic XSk &xdp_buff -> skb
> conversion"), we introduce a helper to convert zerocopy xdp_buff to skb.
> However, in the frag copy, we mistakenly ignore the frag's offset. This
> series adds the missing offset when copying frags in
> xdp_copy_frags_from_zc(). This function is not used anywhere so no
> backport is needed.
> 
> [...]

Here is the summary with links:
  - [net-next,v2,1/2] xsk: respect the offsets when copying frags
    https://git.kernel.org/netdev/net-next/c/ebaebc5eaf43
  - [net-next,v2,2/2] xsk: convert xdp_copy_frags_from_zc() to use page_pool_dev_alloc()
    https://git.kernel.org/netdev/net-next/c/7ead4405e06f

You are awesome, thank you!
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