Merge branch 'xsk-move-cq_cached_prod_lock'

Jason Xing says:

====================
xsk: move cq_cached_prod_lock

From: Jason Xing <kernelxing@tencent.com>

Move cq_cached_prod_lock to avoid touching new cacheline.

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
====================

Link: https://patch.msgid.link/20260104012125.44003-1-kerneljasonxing@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

4 files changed, 17 insertions, 14 deletions

diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
index 92a2358c6ce3..0b1abdb99c9e 100644
--- a/include/net/xsk_buff_pool.h
+++ b/include/net/xsk_buff_pool.h
@@ -90,11 +90,6 @@ struct xsk_buff_pool {
 	 * destructor callback.
 	 */
 	spinlock_t cq_prod_lock;
-	/* Mutual exclusion of the completion ring in the SKB mode.
-	 * Protect: when sockets share a single cq when the same netdev
-	 * and queue id is shared.
-	 */
-	spinlock_t cq_cached_prod_lock;
 	struct xdp_buff_xsk *free_heads[];
 };
 
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index f093c3453f64..3b46bc635c43 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -543,9 +543,9 @@ static int xsk_cq_reserve_locked(struct xsk_buff_pool *pool)
 {
 	int ret;
 
-	spin_lock(&pool->cq_cached_prod_lock);
+	spin_lock(&pool->cq->cq_cached_prod_lock);
 	ret = xskq_prod_reserve(pool->cq);
-	spin_unlock(&pool->cq_cached_prod_lock);
+	spin_unlock(&pool->cq->cq_cached_prod_lock);
 
 	return ret;
 }
@@ -619,9 +619,9 @@ static void xsk_cq_submit_addr_locked(struct xsk_buff_pool *pool,
 
 static void xsk_cq_cancel_locked(struct xsk_buff_pool *pool, u32 n)
 {
-	spin_lock(&pool->cq_cached_prod_lock);
+	spin_lock(&pool->cq->cq_cached_prod_lock);
 	xskq_prod_cancel_n(pool->cq, n);
-	spin_unlock(&pool->cq_cached_prod_lock);
+	spin_unlock(&pool->cq->cq_cached_prod_lock);
 }
 
 INDIRECT_CALLABLE_SCOPE
@@ -1349,6 +1349,13 @@ static int xsk_bind(struct socket *sock, struct sockaddr_unsized *addr, int addr
 		}
 
 		if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
+			/* One fill and completion ring required for each queue id. */
+			if (!xsk_validate_queues(xs)) {
+				err = -EINVAL;
+				sockfd_put(sock);
+				goto out_unlock;
+			}
+
 			/* Share the umem with another socket on another qid
 			 * and/or device.
 			 */
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 51526034c42a..cd5125b6af53 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -91,7 +91,7 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
 	INIT_LIST_HEAD(&pool->xsk_tx_list);
 	spin_lock_init(&pool->xsk_tx_list_lock);
 	spin_lock_init(&pool->cq_prod_lock);
-	spin_lock_init(&pool->cq_cached_prod_lock);
+	spin_lock_init(&xs->cq_tmp->cq_cached_prod_lock);
 	refcount_set(&pool->users, 1);
 
 	pool->fq = xs->fq_tmp;
@@ -247,10 +247,6 @@ int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
 	u16 flags;
 	struct xdp_umem *umem = umem_xs->umem;
 
-	/* One fill and completion ring required for each queue id. */
-	if (!pool->fq || !pool->cq)
-		return -EINVAL;
-
 	flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
 	if (umem_xs->pool->uses_need_wakeup)
 		flags |= XDP_USE_NEED_WAKEUP;
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index 1eb8d9f8b104..ec08d9c102b1 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -46,6 +46,11 @@ struct xsk_queue {
 	u64 invalid_descs;
 	u64 queue_empty_descs;
 	size_t ring_vmalloc_size;
+	/* Mutual exclusion of the completion ring in the SKB mode.
+	 * Protect: when sockets share a single cq when the same netdev
+	 * and queue id is shared.
+	 */
+	spinlock_t cq_cached_prod_lock;
 };
 
 struct parsed_desc {