net: Implement netdev_nl_queue_create_doit

Implement netdev_nl_queue_create_doit which creates a new rx queue in a
virtual netdev and then leases it to a rx queue in a physical netdev.

Example with ynl client:

  # ynl --family netdev --output-json --do queue-create \
        --json '{"ifindex": 8, "type": "rx", "lease": {"ifindex": 4, "queue": {"type": "rx", "id": 15}}}'
  {'id': 1}

Note that the netdevice locking order is always from the virtual to
the physical device.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260402231031.447597-3-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 29 insertions, 5 deletions

diff --git a/include/net/netdev_queues.h b/include/net/netdev_queues.h
index 95ed28212f4e..748b70552ed1 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.
@@ -374,5 +381,11 @@ static inline unsigned int netif_xmit_timeout_ms(struct netdev_queue *txq)
 	})
 
 struct device *netdev_queue_get_dma_dev(struct net_device *dev, int idx);
-
-#endif
+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..1d41c253f0a3 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;
 
 /*
@@ -60,5 +68,8 @@ get_netdev_rx_queue_index(struct netdev_rx_queue *queue)
 }
 
 int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq);
-
-#endif
+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 */