RDMA/nldev: Add support for RDMA monitoring

Introduce a new netlink command to allow rdma event monitoring.
The rdma events supported now are IB device
registration/unregistration and net device attachment/detachment.

Example output of rdma monitor and the commands which trigger
the events:

$ rdma monitor
$ rmmod mlx5_ib
[UNREGISTER]	dev 1 rocep8s0f1
[UNREGISTER]	dev 0 rocep8s0f0

$ modprobe mlx5_ib
[REGISTER]	dev 2 mlx5_0
[NETDEV_ATTACH]	dev 2 mlx5_0 port 1 netdev 4 eth2
[REGISTER]	dev 3 mlx5_1
[NETDEV_ATTACH]	dev 3 mlx5_1 port 1 netdev 5 eth3

$ devlink dev eswitch set pci/0000:08:00.0 mode switchdev
[UNREGISTER]	dev 2 rocep8s0f0
[REGISTER]	dev 4 mlx5_0
[NETDEV_ATTACH]	dev 4 mlx5_0 port 30 netdev 4 eth2

$ echo 4 > /sys/class/net/eth2/device/sriov_numvfs
[NETDEV_ATTACH]	dev 4 rdmap8s0f0 port 2 netdev 7 eth4
[NETDEV_ATTACH]	dev 4 rdmap8s0f0 port 3 netdev 8 eth5
[NETDEV_ATTACH]	dev 4 rdmap8s0f0 port 4 netdev 9 eth6
[NETDEV_ATTACH]	dev 4 rdmap8s0f0 port 5 netdev 10 eth7
[REGISTER]	dev 5 mlx5_0
[NETDEV_ATTACH]	dev 5 mlx5_0 port 1 netdev 11 eth8
[REGISTER]	dev 6 mlx5_0
[NETDEV_ATTACH]	dev 6 mlx5_0 port 1 netdev 12 eth9
[REGISTER]	dev 7 mlx5_0
[NETDEV_ATTACH]	dev 7 mlx5_0 port 1 netdev 13 eth10
[REGISTER]	dev 8 mlx5_0
[NETDEV_ATTACH]	dev 8 mlx5_0 port 1 netdev 14 eth11

$ echo 0 > /sys/class/net/eth2/device/sriov_numvfs
[UNREGISTER]	dev 5 rocep8s0f0v0
[UNREGISTER]	dev 6 rocep8s0f0v1
[UNREGISTER]	dev 7 rocep8s0f0v2
[UNREGISTER]	dev 8 rocep8s0f0v3
[NETDEV_DETACH]	dev 4 rdmap8s0f0 port 2
[NETDEV_DETACH]	dev 4 rdmap8s0f0 port 3
[NETDEV_DETACH]	dev 4 rdmap8s0f0 port 4
[NETDEV_DETACH]	dev 4 rdmap8s0f0 port 5

Signed-off-by: Chiara Meiohas <cmeiohas@nvidia.com>
Signed-off-by: Michael Guralnik <michaelgur@nvidia.com>
Link: https://patch.msgid.link/20240909173025.30422-7-michaelgur@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 9e765c79a892..e029401b5680 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -1351,6 +1351,29 @@ static void prevent_dealloc_device(struct ib_device *ib_dev)
 {
 }
 
+static void ib_device_notify_register(struct ib_device *device)
+{
+	struct net_device *netdev;
+	u32 port;
+	int ret;
+
+	ret = rdma_nl_notify_event(device, 0, RDMA_REGISTER_EVENT);
+	if (ret)
+		return;
+
+	rdma_for_each_port(device, port) {
+		netdev = ib_device_get_netdev(device, port);
+		if (!netdev)
+			continue;
+
+		ret = rdma_nl_notify_event(device, port,
+					   RDMA_NETDEV_ATTACH_EVENT);
+		dev_put(netdev);
+		if (ret)
+			return;
+	}
+}
+
 /**
  * ib_register_device - Register an IB device with IB core
  * @device: Device to register
@@ -1449,6 +1472,8 @@ int ib_register_device(struct ib_device *device, const char *name,
 	dev_set_uevent_suppress(&device->dev, false);
 	/* Mark for userspace that device is ready */
 	kobject_uevent(&device->dev.kobj, KOBJ_ADD);
+
+	ib_device_notify_register(device);
 	ib_device_put(device);
 
 	return 0;
@@ -1491,6 +1516,7 @@ static void __ib_unregister_device(struct ib_device *ib_dev)
 		goto out;
 
 	disable_device(ib_dev);
+	rdma_nl_notify_event(ib_dev, 0, RDMA_UNREGISTER_EVENT);
 
 	/* Expedite removing unregistered pointers from the hash table */
 	free_netdevs(ib_dev);
@@ -2159,6 +2185,7 @@ static void add_ndev_hash(struct ib_port_data *pdata)
 int ib_device_set_netdev(struct ib_device *ib_dev, struct net_device *ndev,
 			 u32 port)
 {
+	enum rdma_nl_notify_event_type etype;
 	struct net_device *old_ndev;
 	struct ib_port_data *pdata;
 	unsigned long flags;
@@ -2190,6 +2217,14 @@ int ib_device_set_netdev(struct ib_device *ib_dev, struct net_device *ndev,
 	spin_unlock_irqrestore(&pdata->netdev_lock, flags);
 
 	add_ndev_hash(pdata);
+
+	/* Make sure that the device is registered before we send events */
+	if (xa_load(&devices, ib_dev->index) != ib_dev)
+		return 0;
+
+	etype = ndev ? RDMA_NETDEV_ATTACH_EVENT : RDMA_NETDEV_DETACH_EVENT;
+	rdma_nl_notify_event(ib_dev, port, etype);
+
 	return 0;
 }
 EXPORT_SYMBOL(ib_device_set_netdev);