devlink: Extend devlink rate API with traffic classes bandwidth management

Introduce support for specifying relative bandwidth shares between traffic classes (TC) in the devlink-rate API. This new option allows users to allocate bandwidth across multiple traffic classes in a single command. This feature provides a more granular control over traffic management, especially for scenarios requiring Enhanced Transmission Selection. Users can now define a relative bandwidth share for each traffic class. For example, assigning share values of 20 to TC0 (TCP/UDP) and 80 to TC5 (RoCE) will result in TC0 receiving 20% and TC5 receiving 80% of the total bandwidth. The actual percentage each class receives depends on the ratio of its share value to the sum of all shares. Example: DEV=pci/0000:08:00.0 $ devlink port function rate add $DEV/vfs_group tx_share 10Gbit \ tx_max 50Gbit tc-bw 0:20 1:0 2:0 3:0 4:0 5:80 6:0 7:0 $ devlink port function rate set $DEV/vfs_group \ tc-bw 0:20 1:0 2:0 3:0 4:0 5:20 6:60 7:0 Example usage with ynl: ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/devlink.yaml \ --do rate-set --json '{ "bus-name": "pci", "dev-name": "0000:08:00.0", "port-index": 1, "rate-tc-bws": [ {"rate-tc-index": 0, "rate-tc-bw": 50}, {"rate-tc-index": 1, "rate-tc-bw": 50}, {"rate-tc-index": 2, "rate-tc-bw": 0}, {"rate-tc-index": 3, "rate-tc-bw": 0}, {"rate-tc-index": 4, "rate-tc-bw": 0}, {"rate-tc-index": 5, "rate-tc-bw": 0}, {"rate-tc-index": 6, "rate-tc-bw": 0}, {"rate-tc-index": 7, "rate-tc-bw": 0} ] }' ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/devlink.yaml \ --do rate-get --json '{ "bus-name": "pci", "dev-name": "0000:08:00.0", "port-index": 1 }' output for rate-get: {'bus-name': 'pci', 'dev-name': '0000:08:00.0', 'port-index': 1, 'rate-tc-bws': [{'rate-tc-bw': 50, 'rate-tc-index': 0}, {'rate-tc-bw': 50, 'rate-tc-index': 1}, {'rate-tc-bw': 0, 'rate-tc-index': 2}, {'rate-tc-bw': 0, 'rate-tc-index': 3}, {'rate-tc-bw': 0, 'rate-tc-index': 4}, {'rate-tc-bw': 0, 'rate-tc-index': 5}, {'rate-tc-bw': 0, 'rate-tc-index': 6}, {'rate-tc-bw': 0, 'rate-tc-index': 7}], 'rate-tx-max': 0, 'rate-tx-priority': 0, 'rate-tx-share': 0, 'rate-tx-weight': 0, 'rate-type': 'leaf'} Signed-off-by: Carolina Jubran <cjubran@nvidia.com> Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Tariq Toukan <tariqt@nvidia.com> Signed-off-by: Mark Bloch <mbloch@nvidia.com> Link: https://patch.msgid.link/20250629142138.361537-3-mbloch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-05 16:54:27 +00:00 · 2025-06-29 17:21:32 +03:00 · 2025-06-29 17:21:32 +03:00 · 566e8f108f
commit 566e8f108f
parent 42401c4238
7 changed files with 195 additions and 5 deletions
--- a/Documentation/netlink/specs/devlink.yaml
+++ b/Documentation/netlink/specs/devlink.yaml
@ -224,6 +224,10 @@ definitions:
        value: 10
      -
        name: binary
+  -
+    name: rate-tc-index-max
+    type: const
+    value: 7

 attribute-sets:
  -
@ -844,7 +848,23 @@ attribute-sets:
      -
        name: region-direct
        type: flag
-
+      -
+        name: rate-tc-bws
+        type: nest
+        multi-attr: true
+        nested-attributes: dl-rate-tc-bws
+      -
+        name: rate-tc-index
+        type: u8
+        checks:
+          max: rate-tc-index-max
+      -
+        name: rate-tc-bw
+        type: u32
+        doc: |
+             Specifies the bandwidth share assigned to the Traffic Class.
+             The bandwidth for the traffic class is determined
+             in proportion to the sum of the shares of all configured classes.
  -
    name: dl-dev-stats
    subset-of: devlink
@ -1249,6 +1269,14 @@ attribute-sets:
      -
        name: flash
        type: flag
+  -
+    name: dl-rate-tc-bws
+    subset-of: devlink
+    attributes:
+      -
+        name: rate-tc-index
+      -
+        name: rate-tc-bw

 operations:
  enum-model: directional
@ -2176,6 +2204,7 @@ operations:
            - rate-tx-priority
            - rate-tx-weight
            - rate-parent-node-name
+            - rate-tc-bws

    -
      name: rate-new
@ -2196,6 +2225,7 @@ operations:
            - rate-tx-priority
            - rate-tx-weight
            - rate-parent-node-name
+            - rate-tc-bws

    -
      name: rate-del
--- a/Documentation/networking/devlink/devlink-port.rst
+++ b/Documentation/networking/devlink/devlink-port.rst
@ -418,6 +418,14 @@ API allows to configure following rate object's parameters:
  to all node children limits. ``tx_max`` is an upper limit for children.
  ``tx_share`` is a total bandwidth distributed among children.

+``tc_bw``
+  Allow users to set the bandwidth allocation per traffic class on rate
+  objects. This enables fine-grained QoS configurations by assigning a relative
+  share value to each traffic class. The bandwidth is distributed in proportion
+  to the share value for each class, relative to the sum of all shares.
+  When applied to a non-leaf node, tc_bw determines how bandwidth is shared
+  among its child elements.
+
 ``tx_priority`` and ``tx_weight`` can be used simultaneously. In that case
 nodes with the same priority form a WFQ subgroup in the sibling group
 and arbitration among them is based on assigned weights.
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@ -118,6 +118,8 @@ struct devlink_rate {

 	u32 tx_priority;
 	u32 tx_weight;
+
+	u32 tc_bw[DEVLINK_RATE_TCS_MAX];
 };

 struct devlink_port {
@ -1486,6 +1488,9 @@ struct devlink_ops {
 					 u32 tx_priority, struct netlink_ext_ack *extack);
 	int (*rate_leaf_tx_weight_set)(struct devlink_rate *devlink_rate, void *priv,
 				       u32 tx_weight, struct netlink_ext_ack *extack);
+	int (*rate_leaf_tc_bw_set)(struct devlink_rate *devlink_rate,
+				   void *priv, u32 *tc_bw,
+				   struct netlink_ext_ack *extack);
 	int (*rate_node_tx_share_set)(struct devlink_rate *devlink_rate, void *priv,
 				      u64 tx_share, struct netlink_ext_ack *extack);
 	int (*rate_node_tx_max_set)(struct devlink_rate *devlink_rate, void *priv,
@ -1494,6 +1499,9 @@ struct devlink_ops {
 					 u32 tx_priority, struct netlink_ext_ack *extack);
 	int (*rate_node_tx_weight_set)(struct devlink_rate *devlink_rate, void *priv,
 				       u32 tx_weight, struct netlink_ext_ack *extack);
+	int (*rate_node_tc_bw_set)(struct devlink_rate *devlink_rate,
+				   void *priv, u32 *tc_bw,
+				   struct netlink_ext_ack *extack);
 	int (*rate_node_new)(struct devlink_rate *rate_node, void **priv,
 			     struct netlink_ext_ack *extack);
 	int (*rate_node_del)(struct devlink_rate *rate_node, void *priv,
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@ -221,6 +221,11 @@ enum devlink_port_flavour {
 				      */
 };

+/* IEEE 802.1Qaz standard supported values. */
+
+#define DEVLINK_RATE_TCS_MAX 8
+#define DEVLINK_RATE_TC_INDEX_MAX (DEVLINK_RATE_TCS_MAX - 1)
+
 enum devlink_rate_type {
 	DEVLINK_RATE_TYPE_LEAF,
 	DEVLINK_RATE_TYPE_NODE,
@ -629,6 +634,10 @@ enum devlink_attr {

 	DEVLINK_ATTR_REGION_DIRECT,		/* flag */

+	DEVLINK_ATTR_RATE_TC_BWS,		/* nested */
+	DEVLINK_ATTR_RATE_TC_INDEX,		/* u8 */
+	DEVLINK_ATTR_RATE_TC_BW,		/* u32 */
+
 	/* Add new attributes above here, update the spec in
 	 * Documentation/netlink/specs/devlink.yaml and re-generate
 	 * net/devlink/netlink_gen.c.
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@ -45,6 +45,11 @@ const struct nla_policy devlink_dl_port_function_nl_policy[DEVLINK_PORT_FN_ATTR_
 	[DEVLINK_PORT_FN_ATTR_CAPS] = NLA_POLICY_BITFIELD32(15),
 };

+const struct nla_policy devlink_dl_rate_tc_bws_nl_policy[DEVLINK_ATTR_RATE_TC_BW + 1] = {
+	[DEVLINK_ATTR_RATE_TC_INDEX] = NLA_POLICY_MAX(NLA_U8, DEVLINK_RATE_TC_INDEX_MAX),
+	[DEVLINK_ATTR_RATE_TC_BW] = { .type = NLA_U32, },
+};
+
 const struct nla_policy devlink_dl_selftest_id_nl_policy[DEVLINK_ATTR_SELFTEST_ID_FLASH + 1] = {
 	[DEVLINK_ATTR_SELFTEST_ID_FLASH] = { .type = NLA_FLAG, },
 };
@ -523,7 +528,7 @@ static const struct nla_policy devlink_rate_get_dump_nl_policy[DEVLINK_ATTR_DEV_
 };

 /* DEVLINK_CMD_RATE_SET - do */
-static const struct nla_policy devlink_rate_set_nl_policy[DEVLINK_ATTR_RATE_TX_WEIGHT + 1] = {
+static const struct nla_policy devlink_rate_set_nl_policy[DEVLINK_ATTR_RATE_TC_BWS + 1] = {
 	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
 	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
 	[DEVLINK_ATTR_RATE_NODE_NAME] = { .type = NLA_NUL_STRING, },
@ -532,10 +537,11 @@ static const struct nla_policy devlink_rate_set_nl_policy[DEVLINK_ATTR_RATE_TX_W
 	[DEVLINK_ATTR_RATE_TX_PRIORITY] = { .type = NLA_U32, },
 	[DEVLINK_ATTR_RATE_TX_WEIGHT] = { .type = NLA_U32, },
 	[DEVLINK_ATTR_RATE_PARENT_NODE_NAME] = { .type = NLA_NUL_STRING, },
+	[DEVLINK_ATTR_RATE_TC_BWS] = NLA_POLICY_NESTED(devlink_dl_rate_tc_bws_nl_policy),
 };

 /* DEVLINK_CMD_RATE_NEW - do */
-static const struct nla_policy devlink_rate_new_nl_policy[DEVLINK_ATTR_RATE_TX_WEIGHT + 1] = {
+static const struct nla_policy devlink_rate_new_nl_policy[DEVLINK_ATTR_RATE_TC_BWS + 1] = {
 	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
 	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
 	[DEVLINK_ATTR_RATE_NODE_NAME] = { .type = NLA_NUL_STRING, },
@ -544,6 +550,7 @@ static const struct nla_policy devlink_rate_new_nl_policy[DEVLINK_ATTR_RATE_TX_W
 	[DEVLINK_ATTR_RATE_TX_PRIORITY] = { .type = NLA_U32, },
 	[DEVLINK_ATTR_RATE_TX_WEIGHT] = { .type = NLA_U32, },
 	[DEVLINK_ATTR_RATE_PARENT_NODE_NAME] = { .type = NLA_NUL_STRING, },
+	[DEVLINK_ATTR_RATE_TC_BWS] = NLA_POLICY_NESTED(devlink_dl_rate_tc_bws_nl_policy),
 };

 /* DEVLINK_CMD_RATE_DEL - do */
@ -1191,7 +1198,7 @@ const struct genl_split_ops devlink_nl_ops[74] = {
 		.doit		= devlink_nl_rate_set_doit,
 		.post_doit	= devlink_nl_post_doit,
 		.policy		= devlink_rate_set_nl_policy,
-		.maxattr	= DEVLINK_ATTR_RATE_TX_WEIGHT,
+		.maxattr	= DEVLINK_ATTR_RATE_TC_BWS,
 		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
 	},
 	{
@ -1201,7 +1208,7 @@ const struct genl_split_ops devlink_nl_ops[74] = {
 		.doit		= devlink_nl_rate_new_doit,
 		.post_doit	= devlink_nl_post_doit,
 		.policy		= devlink_rate_new_nl_policy,
-		.maxattr	= DEVLINK_ATTR_RATE_TX_WEIGHT,
+		.maxattr	= DEVLINK_ATTR_RATE_TC_BWS,
 		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
 	},
 	{
--- a/net/devlink/netlink_gen.h
+++ b/net/devlink/netlink_gen.h
@ -13,6 +13,7 @@

 /* Common nested types */
 extern const struct nla_policy devlink_dl_port_function_nl_policy[DEVLINK_PORT_FN_ATTR_CAPS + 1];
+extern const struct nla_policy devlink_dl_rate_tc_bws_nl_policy[DEVLINK_ATTR_RATE_TC_BW + 1];
 extern const struct nla_policy devlink_dl_selftest_id_nl_policy[DEVLINK_ATTR_SELFTEST_ID_FLASH + 1];

 /* Ops table for devlink */
--- a/net/devlink/rate.c
+++ b/net/devlink/rate.c
@ -80,6 +80,29 @@ devlink_rate_get_from_info(struct devlink *devlink, struct genl_info *info)
 		return ERR_PTR(-EINVAL);
 }

+static int devlink_rate_put_tc_bws(struct sk_buff *msg, u32 *tc_bw)
+{
+	struct nlattr *nla_tc_bw;
+	int i;
+
+	for (i = 0; i < DEVLINK_RATE_TCS_MAX; i++) {
+		nla_tc_bw = nla_nest_start(msg, DEVLINK_ATTR_RATE_TC_BWS);
+		if (!nla_tc_bw)
+			return -EMSGSIZE;
+
+		if (nla_put_u8(msg, DEVLINK_ATTR_RATE_TC_INDEX, i) ||
+		    nla_put_u32(msg, DEVLINK_ATTR_RATE_TC_BW, tc_bw[i]))
+			goto nla_put_failure;
+
+		nla_nest_end(msg, nla_tc_bw);
+	}
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(msg, nla_tc_bw);
+	return -EMSGSIZE;
+}
+
 static int devlink_nl_rate_fill(struct sk_buff *msg,
 				struct devlink_rate *devlink_rate,
 				enum devlink_command cmd, u32 portid, u32 seq,
@ -129,6 +152,9 @@ static int devlink_nl_rate_fill(struct sk_buff *msg,
 				   devlink_rate->parent->name))
 			goto nla_put_failure;

+	if (devlink_rate_put_tc_bws(msg, devlink_rate->tc_bw))
+		goto nla_put_failure;
+
 	genlmsg_end(msg, hdr);
 	return 0;

@ -316,6 +342,87 @@ devlink_nl_rate_parent_node_set(struct devlink_rate *devlink_rate,
 	return 0;
 }

+static int devlink_nl_rate_tc_bw_parse(struct nlattr *parent_nest, u32 *tc_bw,
+				       unsigned long *bitmap,
+				       struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[DEVLINK_ATTR_MAX + 1];
+	u8 tc_index;
+	int err;
+
+	err = nla_parse_nested(tb, DEVLINK_ATTR_MAX, parent_nest,
+			       devlink_dl_rate_tc_bws_nl_policy, extack);
+	if (err)
+		return err;
+
+	if (!tb[DEVLINK_ATTR_RATE_TC_INDEX]) {
+		NL_SET_ERR_ATTR_MISS(extack, parent_nest,
+				     DEVLINK_ATTR_RATE_TC_INDEX);
+		return -EINVAL;
+	}
+
+	tc_index = nla_get_u8(tb[DEVLINK_ATTR_RATE_TC_INDEX]);
+
+	if (!tb[DEVLINK_ATTR_RATE_TC_BW]) {
+		NL_SET_ERR_ATTR_MISS(extack, parent_nest,
+				     DEVLINK_ATTR_RATE_TC_BW);
+		return -EINVAL;
+	}
+
+	if (test_and_set_bit(tc_index, bitmap)) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "Duplicate traffic class index specified (%u)",
+				   tc_index);
+		return -EINVAL;
+	}
+
+	tc_bw[tc_index] = nla_get_u32(tb[DEVLINK_ATTR_RATE_TC_BW]);
+
+	return 0;
+}
+
+static int devlink_nl_rate_tc_bw_set(struct devlink_rate *devlink_rate,
+				     struct genl_info *info)
+{
+	DECLARE_BITMAP(bitmap, DEVLINK_RATE_TCS_MAX) = {};
+	struct devlink *devlink = devlink_rate->devlink;
+	const struct devlink_ops *ops = devlink->ops;
+	u32 tc_bw[DEVLINK_RATE_TCS_MAX] = {};
+	int rem, err = -EOPNOTSUPP, i;
+	struct nlattr *attr;
+
+	nlmsg_for_each_attr_type(attr, DEVLINK_ATTR_RATE_TC_BWS, info->nlhdr,
+				 GENL_HDRLEN, rem) {
+		err = devlink_nl_rate_tc_bw_parse(attr, tc_bw, bitmap,
+						  info->extack);
+		if (err)
+			return err;
+	}
+
+	for (i = 0; i < DEVLINK_RATE_TCS_MAX; i++) {
+		if (!test_bit(i, bitmap)) {
+			NL_SET_ERR_MSG_FMT(info->extack,
+					   "Bandwidth values must be specified for all %u traffic classes",
+					   DEVLINK_RATE_TCS_MAX);
+			return -EINVAL;
+		}
+	}
+
+	if (devlink_rate_is_leaf(devlink_rate))
+		err = ops->rate_leaf_tc_bw_set(devlink_rate, devlink_rate->priv,
+					       tc_bw, info->extack);
+	else if (devlink_rate_is_node(devlink_rate))
+		err = ops->rate_node_tc_bw_set(devlink_rate, devlink_rate->priv,
+					       tc_bw, info->extack);
+
+	if (err)
+		return err;
+
+	memcpy(devlink_rate->tc_bw, tc_bw, sizeof(tc_bw));
+
+	return 0;
+}
+
 static int devlink_nl_rate_set(struct devlink_rate *devlink_rate,
 			       const struct devlink_ops *ops,
 			       struct genl_info *info)
@ -388,6 +495,12 @@ static int devlink_nl_rate_set(struct devlink_rate *devlink_rate,
 			return err;
 	}

+	if (attrs[DEVLINK_ATTR_RATE_TC_BWS]) {
+		err = devlink_nl_rate_tc_bw_set(devlink_rate, info);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }

@ -423,6 +536,13 @@ static bool devlink_rate_set_ops_supported(const struct devlink_ops *ops,
 					    "TX weight set isn't supported for the leafs");
 			return false;
 		}
+		if (attrs[DEVLINK_ATTR_RATE_TC_BWS] &&
+		    !ops->rate_leaf_tc_bw_set) {
+			NL_SET_ERR_MSG_ATTR(info->extack,
+					    attrs[DEVLINK_ATTR_RATE_TC_BWS],
+					    "TC bandwidth set isn't supported for the leafs");
+			return false;
+		}
 	} else if (type == DEVLINK_RATE_TYPE_NODE) {
 		if (attrs[DEVLINK_ATTR_RATE_TX_SHARE] && !ops->rate_node_tx_share_set) {
 			NL_SET_ERR_MSG(info->extack, "TX share set isn't supported for the nodes");
@ -449,6 +569,13 @@ static bool devlink_rate_set_ops_supported(const struct devlink_ops *ops,
 					    "TX weight set isn't supported for the nodes");
 			return false;
 		}
+		if (attrs[DEVLINK_ATTR_RATE_TC_BWS] &&
+		    !ops->rate_node_tc_bw_set) {
+			NL_SET_ERR_MSG_ATTR(info->extack,
+					    attrs[DEVLINK_ATTR_RATE_TC_BWS],
+					    "TC bandwidth set isn't supported for the nodes");
+			return false;
+		}
 	} else {
 		WARN(1, "Unknown type of rate object");
 		return false;