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:

  # ./pyynl/cli.py \
      --spec ~/netlink/specs/netdev.yaml \
      --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>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260115082603.219152-3-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

3 files changed, 24 insertions, 6 deletions

diff --git a/include/net/netdev_queues.h b/include/net/netdev_queues.h
index b55d3b9cb9c2..81dc7cb2360c 100644
--- a/include/net/netdev_queues.h
+++ b/include/net/netdev_queues.h
@@ -130,6 +130,11 @@ void netdev_stat_queue_sum(struct net_device *netdev,
  * @ndo_queue_get_dma_dev: Get dma device for zero-copy operations to be used
  *			   for this queue. Return NULL on error.
  *
+ * @ndo_queue_create: Create a new RX queue which can be leased to another queue.
+ *		      Ops on this queue are redirected to the leased queue e.g.
+ *		      when opening a memory provider. Return the new queue id on
+ *		      success. Return negative error code on failure.
+ *
  * Note that @ndo_queue_mem_alloc and @ndo_queue_mem_free may be called while
  * the interface is closed. @ndo_queue_start and @ndo_queue_stop will only
  * be called for an interface which is open.
@@ -149,9 +154,12 @@ struct netdev_queue_mgmt_ops {
 						  int idx);
 	struct device *		(*ndo_queue_get_dma_dev)(struct net_device *dev,
 							 int idx);
+	int			(*ndo_queue_create)(struct net_device *dev);
 };
 
-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);
+bool netif_rxq_has_mp(struct net_device *dev, unsigned int rxq_idx);
+bool netif_rxq_is_leased(struct net_device *dev, unsigned int rxq_idx);
 
 /**
  * DOC: Lockless queue stopping / waking helpers.
@@ -340,5 +348,10 @@ 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, int idx,
+		       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 8cdcd138b33f..1cacc2451516 100644
--- a/include/net/netdev_rx_queue.h
+++ b/include/net/netdev_rx_queue.h
@@ -28,6 +28,8 @@ struct netdev_rx_queue {
 #endif
 	struct napi_struct		*napi;
 	struct pp_memory_provider_params mp_params;
+	struct netdev_rx_queue		*lease;
+	netdevice_tracker		lease_tracker;
 } ____cacheline_aligned_in_smp;
 
 /*
@@ -57,5 +59,8 @@ 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 */
diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h
index 242e34f771cc..c07cfb431eac 100644
--- a/include/net/xdp_sock_drv.h
+++ b/include/net/xdp_sock_drv.h
@@ -28,7 +28,7 @@ void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries);
 bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc);
 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 max);
 void xsk_tx_release(struct xsk_buff_pool *pool);
-struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
+struct xsk_buff_pool *xsk_get_pool_from_qid(const struct net_device *dev,
 					    u16 queue_id);
 void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool);
 void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool);