[RESEND PATCH net-next] netmem: remove the pp fields from net_iov

[RESEND PATCH net-next] netmem: remove the pp fields from net_iov

[Byungchul Park]

Now that the pp fields in net_iov have no users, remove them from
net_iov and clean up.

Signed-off-by: Byungchul Park <byungchul@sk.com>
---
The original post was:

  https://lore.kernel.org/all/20251121040047.71921-1-byungchul@sk.com/

1/3 was covered by Pavel's patch:

  commit f0243d2b86b97 ("io_uring/zcrx: convert to use netmem_desc").

2/3 was taken by Jakub and merged:

  commit df59bb5b9af3f ("netmem, devmem, tcp: access pp fields through
  @desc in net_iov")

Now that io-uring and net core changes converge in one tree, I'm
resending the 3/3, which is what Jakub asked:

  https://lore.kernel.org/all/20251124184729.7e365941@kernel.org/
---
 include/net/netmem.h | 38 +-------------------------------------
 1 file changed, 1 insertion(+), 37 deletions(-)

diff --git a/include/net/netmem.h b/include/net/netmem.h
index a96b3e5e5574..a6d65ced5231 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -93,23 +93,7 @@ enum net_iov_type {
  *		supported.
  */
 struct net_iov {
-	union {
-		struct netmem_desc desc;
-
-		/* XXX: The following part should be removed once all
-		 * the references to them are converted so as to be
-		 * accessed via netmem_desc e.g. niov->desc.pp instead
-		 * of niov->pp.
-		 */
-		struct {
-			unsigned long _flags;
-			unsigned long pp_magic;
-			struct page_pool *pp;
-			unsigned long _pp_mapping_pad;
-			unsigned long dma_addr;
-			atomic_long_t pp_ref_count;
-		};
-	};
+	struct netmem_desc desc;
 	struct net_iov_area *owner;
 	enum net_iov_type type;
 };
@@ -123,26 +107,6 @@ struct net_iov_area {
 	unsigned long base_virtual;
 };
 
-/* net_iov is union'ed with struct netmem_desc mirroring struct page, so
- * the page_pool can access these fields without worrying whether the
- * underlying fields are accessed via netmem_desc or directly via
- * net_iov, until all the references to them are converted so as to be
- * accessed via netmem_desc e.g. niov->desc.pp instead of niov->pp.
- *
- * The non-net stack fields of struct page are private to the mm stack
- * and must never be mirrored to net_iov.
- */
-#define NET_IOV_ASSERT_OFFSET(desc, iov)                    \
-	static_assert(offsetof(struct netmem_desc, desc) == \
-		      offsetof(struct net_iov, iov))
-NET_IOV_ASSERT_OFFSET(_flags, _flags);
-NET_IOV_ASSERT_OFFSET(pp_magic, pp_magic);
-NET_IOV_ASSERT_OFFSET(pp, pp);
-NET_IOV_ASSERT_OFFSET(_pp_mapping_pad, _pp_mapping_pad);
-NET_IOV_ASSERT_OFFSET(dma_addr, dma_addr);
-NET_IOV_ASSERT_OFFSET(pp_ref_count, pp_ref_count);
-#undef NET_IOV_ASSERT_OFFSET
-
 static inline struct net_iov_area *net_iov_owner(const struct net_iov *niov)
 {
 	return niov->owner;
-- 
2.17.1

Re: [RESEND PATCH net-next] netmem: remove the pp fields from net_iov

[Simon Horman]

On Tue, Feb 24, 2026 at 03:14:24PM +0900, Byungchul Park wrote:
> Now that the pp fields in net_iov have no users, remove them from
> net_iov and clean up.
> 
> Signed-off-by: Byungchul Park <byungchul@sk.com>

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [RESEND PATCH net-next] netmem: remove the pp fields from net_iov

[Pavel Begunkov]

On 2/24/26 06:14, Byungchul Park wrote:
> Now that the pp fields in net_iov have no users, remove them from
> net_iov and clean up.

Looks good, it's great to get rid of all this aliasing.

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>

-- 
Pavel Begunkov

Re: [RESEND PATCH net-next] netmem: remove the pp fields from net_iov

[Toke Høiland-Jørgensen]

Byungchul Park <byungchul@sk.com> writes:

> Now that the pp fields in net_iov have no users, remove them from
> net_iov and clean up.
>
> Signed-off-by: Byungchul Park <byungchul@sk.com>

Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>