Merge branch 'devlink-io-eqs'

Parav Pandit says:

====================
devlink: Add port function attribute for IO EQs

Currently, PCI SFs and VFs use IO event queues to deliver netdev per
channel events. The number of netdev channels is a function of IO
event queues. In the second scenario of an RDMA device, the
completion vectors are also a function of IO event queues. Currently, an
administrator on the hypervisor has no means to provision the number
of IO event queues for the SF device or the VF device. Device/firmware
determines some arbitrary value for these IO event queues. Due to this,
the SF netdev channels are unpredictable, and consequently, the
performance is too.

This short series introduces a new port function attribute: max_io_eqs.
The goal is to provide administrators at the hypervisor level with the
ability to provision the maximum number of IO event queues for a
function. This gives the control to the administrator to provision
right number of IO event queues and have predictable performance.

Examples of when an administrator provisions (set) maximum number of
IO event queues when using switchdev mode:

  $ devlink port show pci/0000:06:00.0/1
      pci/0000:06:00.0/1: type eth netdev enp6s0pf0vf0 flavour pcivf pfnum 0 vfnum 0
          function:
          hw_addr 00:00:00:00:00:00 roce enable max_io_eqs 10

  $ devlink port function set pci/0000:06:00.0/1 max_io_eqs 20

  $ devlink port show pci/0000:06:00.0/1
      pci/0000:06:00.0/1: type eth netdev enp6s0pf0vf0 flavour pcivf pfnum 0 vfnum 0
          function:
          hw_addr 00:00:00:00:00:00 roce enable max_io_eqs 20

This sets the corresponding maximum IO event queues of the function
before it is enumerated. Thus, when the VF/SF driver reads the
capability from the device, it sees the value provisioned by the
hypervisor. The driver is then able to configure the number of channels
for the net device, as well as the number of completion vectors
for the RDMA device. The device/firmware also honors the provisioned
value, hence any VF/SF driver attempting to create IO EQs
beyond provisioned value results in an error.

With above setting now, the administrator is able to achieve the 2x
performance on SFs with 20 channels. In second example when SF was
provisioned for a container with 2 cpus, the administrator provisioned only
2 IO event queues, thereby saving device resources.

With the above settings now in place, the administrator achieved 2x
performance with the SF device with 20 channels. In the second example,
when the SF was provisioned for a container with 2 CPUs, the administrator
provisioned only 2 IO event queues, thereby saving device resources.

changelog:
v2->v3:
- limited to 80 chars per line in devlink
- fixed comments from Jakub in mlx5 driver to fix missing mutex unlock
  on error path
v1->v2:
- limited comment to 80 chars per line in header file
- fixed set function variables for reverse christmas tree
- fixed comments from Kalesh
- fixed missing kfree in get call
- returning error code for get cmd failure
- fixed error msg copy paste error in set on cmd failure
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/devlink/devlink-port.rst

@@ -134,6 +134,9 @@ Users may also set the IPsec crypto capability of the function using
 Users may also set the IPsec packet capability of the function using
 `devlink port function set ipsec_packet` command.
 
+Users may also set the maximum IO event queues of the function
+using `devlink port function set max_io_eqs` command.
+
 Function attributes
 ===================
 
@@ -295,6 +298,36 @@ policy is processed in software by the kernel.
         function:
             hw_addr 00:00:00:00:00:00 ipsec_packet enabled
 
+Maximum IO events queues setup
+------------------------------
+When user sets maximum number of IO event queues for a SF or
+a VF, such function driver is limited to consume only enforced
+number of IO event queues.
+
+IO event queues deliver events related to IO queues, including network
+device transmit and receive queues (txq and rxq) and RDMA Queue Pairs (QPs).
+For example, the number of netdevice channels and RDMA device completion
+vectors are derived from the function's IO event queues. Usually, the number
+of interrupt vectors consumed by the driver is limited by the number of IO
+event queues per device, as each of the IO event queues is connected to an
+interrupt vector.
+
+- Get maximum IO event queues of the VF device::
+
+    $ devlink port show pci/0000:06:00.0/2
+    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
+        function:
+            hw_addr 00:00:00:00:00:00 ipsec_packet disabled max_io_eqs 10
+
+- Set maximum IO event queues of the VF device::
+
+    $ devlink port function set pci/0000:06:00.0/2 max_io_eqs 32
+
+    $ devlink port show pci/0000:06:00.0/2
+    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
+        function:
+            hw_addr 00:00:00:00:00:00 ipsec_packet disabled max_io_eqs 32
+
 Subfunction
 ============
 

drivers/net/ethernet/mellanox/mlx5/core/esw/devlink_port.c

@@ -98,6 +98,8 @@ static const struct devlink_port_ops mlx5_esw_pf_vf_dl_port_ops = {
 	.port_fn_ipsec_packet_get = mlx5_devlink_port_fn_ipsec_packet_get,
 	.port_fn_ipsec_packet_set = mlx5_devlink_port_fn_ipsec_packet_set,
 #endif /* CONFIG_XFRM_OFFLOAD */
+	.port_fn_max_io_eqs_get = mlx5_devlink_port_fn_max_io_eqs_get,
+	.port_fn_max_io_eqs_set = mlx5_devlink_port_fn_max_io_eqs_set,
 };
 
 static void mlx5_esw_offloads_sf_devlink_port_attrs_set(struct mlx5_eswitch *esw,
@@ -143,6 +145,8 @@ static const struct devlink_port_ops mlx5_esw_dl_sf_port_ops = {
 	.port_fn_state_get = mlx5_devlink_sf_port_fn_state_get,
 	.port_fn_state_set = mlx5_devlink_sf_port_fn_state_set,
 #endif
+	.port_fn_max_io_eqs_get = mlx5_devlink_port_fn_max_io_eqs_get,
+	.port_fn_max_io_eqs_set = mlx5_devlink_port_fn_max_io_eqs_set,
 };
 
 int mlx5_esw_offloads_devlink_port_register(struct mlx5_eswitch *esw, struct mlx5_vport *vport)

drivers/net/ethernet/mellanox/mlx5/core/eswitch.h

@@ -573,6 +573,13 @@ int mlx5_devlink_port_fn_ipsec_packet_get(struct devlink_port *port, bool *is_en
 int mlx5_devlink_port_fn_ipsec_packet_set(struct devlink_port *port, bool enable,
 					  struct netlink_ext_ack *extack);
 #endif /* CONFIG_XFRM_OFFLOAD */
+int mlx5_devlink_port_fn_max_io_eqs_get(struct devlink_port *port,
+					u32 *max_io_eqs,
+					struct netlink_ext_ack *extack);
+int mlx5_devlink_port_fn_max_io_eqs_set(struct devlink_port *port,
+					u32 max_io_eqs,
+					struct netlink_ext_ack *extack);
+
 void *mlx5_eswitch_get_uplink_priv(struct mlx5_eswitch *esw, u8 rep_type);
 
 int __mlx5_eswitch_set_vport_vlan(struct mlx5_eswitch *esw,

drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c

@@ -66,6 +66,8 @@
 
 #define MLX5_ESW_FT_OFFLOADS_DROP_RULE (1)
 
+#define MLX5_ESW_MAX_CTRL_EQS 4
+
 static struct esw_vport_tbl_namespace mlx5_esw_vport_tbl_mirror_ns = {
 	.max_fte = MLX5_ESW_VPORT_TBL_SIZE,
 	.max_num_groups = MLX5_ESW_VPORT_TBL_NUM_GROUPS,
@@ -4557,3 +4559,98 @@ int mlx5_devlink_port_fn_ipsec_packet_set(struct devlink_port *port,
 	return err;
 }
 #endif /* CONFIG_XFRM_OFFLOAD */
+
+int
+mlx5_devlink_port_fn_max_io_eqs_get(struct devlink_port *port, u32 *max_io_eqs,
+				    struct netlink_ext_ack *extack)
+{
+	struct mlx5_vport *vport = mlx5_devlink_port_vport_get(port);
+	int query_out_sz = MLX5_ST_SZ_BYTES(query_hca_cap_out);
+	u16 vport_num = vport->vport;
+	struct mlx5_eswitch *esw;
+	void *query_ctx;
+	void *hca_caps;
+	u32 max_eqs;
+	int err;
+
+	esw = mlx5_devlink_eswitch_nocheck_get(port->devlink);
+	if (!MLX5_CAP_GEN(esw->dev, vhca_resource_manager)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Device doesn't support VHCA management");
+		return -EOPNOTSUPP;
+	}
+
+	query_ctx = kzalloc(query_out_sz, GFP_KERNEL);
+	if (!query_ctx)
+		return -ENOMEM;
+
+	mutex_lock(&esw->state_lock);
+	err = mlx5_vport_get_other_func_cap(esw->dev, vport_num, query_ctx,
+					    MLX5_CAP_GENERAL);
+	if (err) {
+		NL_SET_ERR_MSG_MOD(extack, "Failed getting HCA caps");
+		goto out;
+	}
+
+	hca_caps = MLX5_ADDR_OF(query_hca_cap_out, query_ctx, capability);
+	max_eqs = MLX5_GET(cmd_hca_cap, hca_caps, max_num_eqs);
+	if (max_eqs < MLX5_ESW_MAX_CTRL_EQS)
+		*max_io_eqs = 0;
+	else
+		*max_io_eqs = max_eqs - MLX5_ESW_MAX_CTRL_EQS;
+out:
+	mutex_unlock(&esw->state_lock);
+	kfree(query_ctx);
+	return err;
+}
+
+int
+mlx5_devlink_port_fn_max_io_eqs_set(struct devlink_port *port, u32 max_io_eqs,
+				    struct netlink_ext_ack *extack)
+{
+	struct mlx5_vport *vport = mlx5_devlink_port_vport_get(port);
+	int query_out_sz = MLX5_ST_SZ_BYTES(query_hca_cap_out);
+	u16 vport_num = vport->vport;
+	struct mlx5_eswitch *esw;
+	void *query_ctx;
+	void *hca_caps;
+	u16 max_eqs;
+	int err;
+
+	esw = mlx5_devlink_eswitch_nocheck_get(port->devlink);
+	if (!MLX5_CAP_GEN(esw->dev, vhca_resource_manager)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Device doesn't support VHCA management");
+		return -EOPNOTSUPP;
+	}
+
+	if (check_add_overflow(max_io_eqs, MLX5_ESW_MAX_CTRL_EQS, &max_eqs)) {
+		NL_SET_ERR_MSG_MOD(extack, "Supplied value out of range");
+		return -EINVAL;
+	}
+
+	query_ctx = kzalloc(query_out_sz, GFP_KERNEL);
+	if (!query_ctx)
+		return -ENOMEM;
+
+	mutex_lock(&esw->state_lock);
+	err = mlx5_vport_get_other_func_cap(esw->dev, vport_num, query_ctx,
+					    MLX5_CAP_GENERAL);
+	if (err) {
+		NL_SET_ERR_MSG_MOD(extack, "Failed getting HCA caps");
+		goto out;
+	}
+
+	hca_caps = MLX5_ADDR_OF(query_hca_cap_out, query_ctx, capability);
+	MLX5_SET(cmd_hca_cap, hca_caps, max_num_eqs, max_eqs);
+
+	err = mlx5_vport_set_other_func_cap(esw->dev, hca_caps, vport_num,
+					    MLX5_SET_HCA_CAP_OP_MOD_GENERAL_DEVICE);
+	if (err)
+		NL_SET_ERR_MSG_MOD(extack, "Failed setting HCA caps");
+
+out:
+	mutex_unlock(&esw->state_lock);
+	kfree(query_ctx);
+	return err;
+}

include/net/devlink.h

@@ -1602,6 +1602,14 @@ void devlink_free(struct devlink *devlink);
  *			      capability. Should be used by device drivers to
  *			      enable/disable ipsec_packet capability of a
  *			      function managed by the devlink port.
+ * @port_fn_max_io_eqs_get: Callback used to get port function's maximum number
+ *			    of event queues. Should be used by device drivers to
+ *			    report the maximum event queues of a function
+ *			    managed by the devlink port.
+ * @port_fn_max_io_eqs_set: Callback used to set port function's maximum number
+ *			    of event queues. Should be used by device drivers to
+ *			    configure maximum number of event queues
+ *			    of a function managed by the devlink port.
  *
  * Note: Driver should return -EOPNOTSUPP if it doesn't support
  * port function (@port_fn_*) handling for a particular port.
@@ -1651,6 +1659,12 @@ struct devlink_port_ops {
 	int (*port_fn_ipsec_packet_set)(struct devlink_port *devlink_port,
 					bool enable,
 					struct netlink_ext_ack *extack);
+	int (*port_fn_max_io_eqs_get)(struct devlink_port *devlink_port,
+				      u32 *max_eqs,
+				      struct netlink_ext_ack *extack);
+	int (*port_fn_max_io_eqs_set)(struct devlink_port *devlink_port,
+				      u32 max_eqs,
+				      struct netlink_ext_ack *extack);
 };
 
 void devlink_port_init(struct devlink *devlink,

include/uapi/linux/devlink.h

@@ -686,6 +686,7 @@ enum devlink_port_function_attr {
 	DEVLINK_PORT_FN_ATTR_OPSTATE,	/* u8 */
 	DEVLINK_PORT_FN_ATTR_CAPS,	/* bitfield32 */
 	DEVLINK_PORT_FN_ATTR_DEVLINK,	/* nested */
+	DEVLINK_PORT_FN_ATTR_MAX_IO_EQS,	/* u32 */
 
 	__DEVLINK_PORT_FUNCTION_ATTR_MAX,
 	DEVLINK_PORT_FUNCTION_ATTR_MAX = __DEVLINK_PORT_FUNCTION_ATTR_MAX - 1

net/devlink/port.c

@@ -16,6 +16,7 @@ static const struct nla_policy devlink_function_nl_policy[DEVLINK_PORT_FUNCTION_
 				 DEVLINK_PORT_FN_STATE_ACTIVE),
 	[DEVLINK_PORT_FN_ATTR_CAPS] =
 		NLA_POLICY_BITFIELD32(DEVLINK_PORT_FN_CAPS_VALID_MASK),
+	[DEVLINK_PORT_FN_ATTR_MAX_IO_EQS] = { .type = NLA_U32 },
 };
 
 #define ASSERT_DEVLINK_PORT_REGISTERED(devlink_port)				\
@@ -182,6 +183,30 @@ static int devlink_port_fn_caps_fill(struct devlink_port *devlink_port,
 	return 0;
 }
 
+static int devlink_port_fn_max_io_eqs_fill(struct devlink_port *port,
+					   struct sk_buff *msg,
+					   struct netlink_ext_ack *extack,
+					   bool *msg_updated)
+{
+	u32 max_io_eqs;
+	int err;
+
+	if (!port->ops->port_fn_max_io_eqs_get)
+		return 0;
+
+	err = port->ops->port_fn_max_io_eqs_get(port, &max_io_eqs, extack);
+	if (err) {
+		if (err == -EOPNOTSUPP)
+			return 0;
+		return err;
+	}
+	err = nla_put_u32(msg, DEVLINK_PORT_FN_ATTR_MAX_IO_EQS, max_io_eqs);
+	if (err)
+		return err;
+	*msg_updated = true;
+	return 0;
+}
+
 int devlink_nl_port_handle_fill(struct sk_buff *msg, struct devlink_port *devlink_port)
 {
 	if (devlink_nl_put_handle(msg, devlink_port->devlink))
@@ -409,6 +434,18 @@ static int devlink_port_fn_caps_set(struct devlink_port *devlink_port,
 	return 0;
 }
 
+static int
+devlink_port_fn_max_io_eqs_set(struct devlink_port *devlink_port,
+			       const struct nlattr *attr,
+			       struct netlink_ext_ack *extack)
+{
+	u32 max_io_eqs;
+
+	max_io_eqs = nla_get_u32(attr);
+	return devlink_port->ops->port_fn_max_io_eqs_set(devlink_port,
+							 max_io_eqs, extack);
+}
+
 static int
 devlink_nl_port_function_attrs_put(struct sk_buff *msg, struct devlink_port *port,
 				   struct netlink_ext_ack *extack)
@@ -428,6 +465,9 @@ devlink_nl_port_function_attrs_put(struct sk_buff *msg, struct devlink_port *por
 	if (err)
 		goto out;
 	err = devlink_port_fn_state_fill(port, msg, extack, &msg_updated);
+	if (err)
+		goto out;
+	err = devlink_port_fn_max_io_eqs_fill(port, msg, extack, &msg_updated);
 	if (err)
 		goto out;
 	err = devlink_rel_devlink_handle_put(msg, port->devlink,
@@ -726,6 +766,12 @@ static int devlink_port_function_validate(struct devlink_port *devlink_port,
 			}
 		}
 	}
+	if (tb[DEVLINK_PORT_FN_ATTR_MAX_IO_EQS] &&
+	    !ops->port_fn_max_io_eqs_set) {
+		NL_SET_ERR_MSG_ATTR(extack, tb[DEVLINK_PORT_FN_ATTR_MAX_IO_EQS],
+				    "Function does not support max_io_eqs setting");
+		return -EOPNOTSUPP;
+	}
 	return 0;
 }
 
@@ -761,6 +807,13 @@ static int devlink_port_function_set(struct devlink_port *port,
 			return err;
 	}
 
+	attr = tb[DEVLINK_PORT_FN_ATTR_MAX_IO_EQS];
+	if (attr) {
+		err = devlink_port_fn_max_io_eqs_set(port, attr, extack);
+		if (err)
+			return err;
+	}
+
 	/* Keep this as the last function attribute set, so that when
 	 * multiple port function attributes are set along with state,
 	 * Those can be applied first before activating the state.