Merge branch 'netkit-support-for-io_uring-zero-copy-and-af_xdp'

Daniel Borkmann says:

====================
netkit: Support for io_uring zero-copy and AF_XDP

Containers use virtual netdevs to route traffic from a physical netdev
in the host namespace. They do not have access to the physical netdev
in the host and thus can't use memory providers or AF_XDP that require
reconfiguring/restarting queues in the physical netdev.

This patchset adds the concept of queue leasing to virtual netdevs that
allow containers to use memory providers and AF_XDP at native speed.
Leased queues are bound to a real queue in a physical netdev and act
as a proxy.

Memory providers and AF_XDP operations take an ifindex and queue id,
so containers would pass in an ifindex for a virtual netdev and a queue
id of a leased queue, which then gets proxied to the underlying real
queue.

We have implemented support for this concept in netkit and tested the
latter against Nvidia ConnectX-6 (mlx5) as well as Broadcom BCM957504
(bnxt_en) 100G NICs. For more details see the individual patches.
====================

Link: https://patch.msgid.link/20260402231031.447597-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 48 insertions, 12 deletions

diff --git a/include/net/netdev_queues.h b/include/net/netdev_queues.h
index 95ed28212f4e..70c9fe9e83cc 100644
--- a/include/net/netdev_queues.h
+++ b/include/net/netdev_queues.h
@@ -150,6 +150,11 @@ enum {
  *			When NIC-wide config is changed the callback will
  *			be invoked for all queues.
  *
+ * @ndo_queue_create:	Create a new RX queue on a virtual device that will
+ *			be paired with a physical device's queue via leasing.
+ *			Return the new queue id on success, negative error
+ *			on failure.
+ *
  * @supported_params:	Bitmask of supported parameters, see QCFG_*.
  *
  * Note that @ndo_queue_mem_alloc and @ndo_queue_mem_free may be called while
@@ -178,6 +183,8 @@ struct netdev_queue_mgmt_ops {
 				     struct netlink_ext_ack *extack);
 	struct device *	(*ndo_queue_get_dma_dev)(struct net_device *dev,
 						 int idx);
+	int	(*ndo_queue_create)(struct net_device *dev,
+				    struct netlink_ext_ack *extack);
 
 	unsigned int supported_params;
 };
@@ -185,7 +192,7 @@ struct netdev_queue_mgmt_ops {
 void netdev_queue_config(struct net_device *dev, int rxq,
 			 struct netdev_queue_config *qcfg);
 
-bool netif_rxq_has_unreadable_mp(struct net_device *dev, int idx);
+bool netif_rxq_has_unreadable_mp(struct net_device *dev, unsigned int rxq_idx);
 
 /**
  * DOC: Lockless queue stopping / waking helpers.
@@ -373,6 +380,14 @@ static inline unsigned int netif_xmit_timeout_ms(struct netdev_queue *txq)
 					 get_desc, start_thrs);		\
 	})
 
-struct device *netdev_queue_get_dma_dev(struct net_device *dev, int idx);
-
-#endif
+struct device *netdev_queue_get_dma_dev(struct net_device *dev,
+					unsigned int idx,
+					enum netdev_queue_type type);
+bool netdev_can_create_queue(const struct net_device *dev,
+			     struct netlink_ext_ack *extack);
+bool netdev_can_lease_queue(const struct net_device *dev,
+			    struct netlink_ext_ack *extack);
+bool netdev_queue_busy(struct net_device *dev, unsigned int idx,
+		       enum netdev_queue_type type,
+		       struct netlink_ext_ack *extack);
+#endif /* _LINUX_NET_QUEUES_H */
diff --git a/include/net/netdev_rx_queue.h b/include/net/netdev_rx_queue.h
index 08f81329fc11..7e98c679ea84 100644
--- a/include/net/netdev_rx_queue.h
+++ b/include/net/netdev_rx_queue.h
@@ -31,6 +31,14 @@ struct netdev_rx_queue {
 	struct napi_struct		*napi;
 	struct netdev_queue_config	qcfg;
 	struct pp_memory_provider_params mp_params;
+
+	/* If a queue is leased, then the lease pointer is always
+	 * valid. From the physical device it points to the virtual
+	 * queue, and from the virtual device it points to the
+	 * physical queue.
+	 */
+	struct netdev_rx_queue		*lease;
+	netdevice_tracker		lease_tracker;
 } ____cacheline_aligned_in_smp;
 
 /*
@@ -59,6 +67,23 @@ get_netdev_rx_queue_index(struct netdev_rx_queue *queue)
 	return index;
 }
 
-int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq);
+enum netif_lease_dir {
+	NETIF_VIRT_TO_PHYS,
+	NETIF_PHYS_TO_VIRT,
+};
 
-#endif
+struct netdev_rx_queue *
+__netif_get_rx_queue_lease(struct net_device **dev, unsigned int *rxq,
+			   enum netif_lease_dir dir);
+
+struct netdev_rx_queue *
+netif_get_rx_queue_lease_locked(struct net_device **dev, unsigned int *rxq);
+void netif_put_rx_queue_lease_locked(struct net_device *orig_dev,
+				     struct net_device *dev);
+
+int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq);
+void netdev_rx_queue_lease(struct netdev_rx_queue *rxq_dst,
+			   struct netdev_rx_queue *rxq_src);
+void netdev_rx_queue_unlease(struct netdev_rx_queue *rxq_dst,
+			     struct netdev_rx_queue *rxq_src);
+#endif /* _LINUX_NETDEV_RX_QUEUE_H */
diff --git a/include/net/page_pool/memory_provider.h b/include/net/page_pool/memory_provider.h
index ada4f968960a..255ce4cfd975 100644
--- a/include/net/page_pool/memory_provider.h
+++ b/include/net/page_pool/memory_provider.h
@@ -23,14 +23,10 @@ bool net_mp_niov_set_dma_addr(struct net_iov *niov, dma_addr_t addr);
 void net_mp_niov_set_page_pool(struct page_pool *pool, struct net_iov *niov);
 void net_mp_niov_clear_page_pool(struct net_iov *niov);
 
-int net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,
-		    struct pp_memory_provider_params *p);
-int __net_mp_open_rxq(struct net_device *dev, unsigned int rxq_idx,
+int netif_mp_open_rxq(struct net_device *dev, unsigned int rxq_idx,
 		      const struct pp_memory_provider_params *p,
 		      struct netlink_ext_ack *extack);
-void net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,
-		      struct pp_memory_provider_params *old_p);
-void __net_mp_close_rxq(struct net_device *dev, unsigned int rxq_idx,
+void netif_mp_close_rxq(struct net_device *dev, unsigned int rxq_idx,
 			const struct pp_memory_provider_params *old_p);
 
 /**