3 files changed, 44 insertions, 24 deletions

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 7e16336044b2..1140b2a120ca 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -1320,14 +1320,6 @@ struct xdp_umem_reg_v1 {
 	__u32 headroom;
 };
 
-struct xdp_umem_reg_v2 {
-	__u64 addr; /* Start of packet data area */
-	__u64 len; /* Length of packet data area */
-	__u32 chunk_size;
-	__u32 headroom;
-	__u32 flags;
-};
-
 static int xsk_setsockopt(struct socket *sock, int level, int optname,
 			  sockptr_t optval, unsigned int optlen)
 {
@@ -1371,10 +1363,19 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname,
 
 		if (optlen < sizeof(struct xdp_umem_reg_v1))
 			return -EINVAL;
-		else if (optlen < sizeof(struct xdp_umem_reg_v2))
-			mr_size = sizeof(struct xdp_umem_reg_v1);
 		else if (optlen < sizeof(mr))
-			mr_size = sizeof(struct xdp_umem_reg_v2);
+			mr_size = sizeof(struct xdp_umem_reg_v1);
+
+		BUILD_BUG_ON(sizeof(struct xdp_umem_reg_v1) >= sizeof(struct xdp_umem_reg));
+
+		/* Make sure the last field of the struct doesn't have
+		 * uninitialized padding. All padding has to be explicit
+		 * and has to be set to zero by the userspace to make
+		 * struct xdp_umem_reg extensible in the future.
+		 */
+		BUILD_BUG_ON(offsetof(struct xdp_umem_reg, tx_metadata_len) +
+			     sizeof_field(struct xdp_umem_reg, tx_metadata_len) !=
+			     sizeof(struct xdp_umem_reg));
 
 		if (copy_from_sockptr(&mr, optval, mr_size))
 			return -EFAULT;
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index c0e0204b9630..521a2938e50a 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -211,6 +211,11 @@ int xp_assign_dev(struct xsk_buff_pool *pool,
 		goto err_unreg_pool;
 	}
 
+	if (dev_get_min_mp_channel_count(netdev)) {
+		err = -EBUSY;
+		goto err_unreg_pool;
+	}
+
 	bpf.command = XDP_SETUP_XSK_POOL;
 	bpf.xsk.pool = pool;
 	bpf.xsk.queue_id = queue_id;
@@ -623,20 +628,31 @@ static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u3
 	return nb_entries;
 }
 
-u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
+static u32 xp_alloc_slow(struct xsk_buff_pool *pool, struct xdp_buff **xdp,
+			 u32 max)
 {
-	u32 nb_entries1 = 0, nb_entries2;
+	int i;
 
-	if (unlikely(pool->dev && dma_dev_need_sync(pool->dev))) {
+	for (i = 0; i < max; i++) {
 		struct xdp_buff *buff;
 
-		/* Slow path */
 		buff = xp_alloc(pool);
-		if (buff)
-			*xdp = buff;
-		return !!buff;
+		if (unlikely(!buff))
+			return i;
+		*xdp = buff;
+		xdp++;
 	}
 
+	return max;
+}
+
+u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
+{
+	u32 nb_entries1 = 0, nb_entries2;
+
+	if (unlikely(pool->dev && dma_dev_need_sync(pool->dev)))
+		return xp_alloc_slow(pool, xdp, max);
+
 	if (unlikely(pool->free_list_cnt)) {
 		nb_entries1 = xp_alloc_reused(pool, xdp, max);
 		if (nb_entries1 == max)
@@ -656,9 +672,17 @@ EXPORT_SYMBOL(xp_alloc_batch);
 
 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
 {
+	u32 req_count, avail_count;
+
 	if (pool->free_list_cnt >= count)
 		return true;
-	return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt);
+
+	req_count = count - pool->free_list_cnt;
+	avail_count = xskq_cons_nb_entries(pool->fq, req_count);
+	if (!avail_count)
+		pool->fq->queue_empty_descs++;
+
+	return avail_count >= req_count;
 }
 EXPORT_SYMBOL(xp_can_alloc);
 
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index 6f2d1621c992..406b20dfee8d 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -306,11 +306,6 @@ static inline u32 xskq_cons_nb_entries(struct xsk_queue *q, u32 max)
 	return entries >= max ? max : entries;
 }
 
-static inline bool xskq_cons_has_entries(struct xsk_queue *q, u32 cnt)
-{
-	return xskq_cons_nb_entries(q, cnt) >= cnt;
-}
-
 static inline bool xskq_cons_peek_addr_unchecked(struct xsk_queue *q, u64 *addr)
 {
 	if (q->cached_prod == q->cached_cons)