[PATCH net-next 00/14] devlink and mlx5: Support cross-function rate scheduling

[PATCH net-next 00/14] devlink and mlx5: Support cross-function rate scheduling

[Tariq Toukan]

Hi,

This series by Cosmin and Jiri adds support for cross-function rate
scheduling in devlink and mlx5.
This is a different approach for the series discussed in [2] earlier
this year. See detailed feature description by Cosmin below [1].

Code dependency:
This series should apply cleanly after the pulling of
'net-2025_11_19_05_03', specifically commit f94c1a114ac2 ("devlink:
rate: Unset parent pointer in devl_rate_nodes_destroy").

Regards,
Tariq


[1]
devlink objects support rate management for TX scheduling, which
involves maintaining a tree of rate nodes that corresponds to TX
schedulers in hardware. 'man devlink-rate' has the full details.

The tree of rate nodes is maintained per devlink object, protected by
the devlink lock.

There exists hardware capable of instantiating TX scheduling trees
spanning multiple functions of the same physical device (and thus
devlink objects) and therefore the current API and locking scheme is
insufficient.

This patch series changes the devlink rate implementation and API to
allow supporting such hardware and managing TX scheduling trees across
multiple functions of a physical device.

Modeling this requires having devlink rate nodes with parents in other
devlink objects. A naive approach that relies on the current
one-lock-per-devlink model is impossible, as it would require in some
cases acquiring multiple devlink locks in the correct order.

The solution proposed in this patch series consists of two parts:

1. Modeling the underlying physical NIC as a shared devlink object on
   the faux bus and nesting all its PF devlink instances in it.

2. Changing the devlink rate implementation to store rates in this
   shared devlink object, if it exists, and use its lock to protect
   against concurrent changes of the scheduling tree.

With these in place, cross-esw scheduling support is added to mlx5.  The
neat part about this approach is that it works for SFs as well, which
are already nested in their parent PF instances.

V1 of this patch series was sent a long time ago [2], using a different
approach of storing rates in a shared rate domain with special locking
rules. This new approach uses standard devlink instances and nesting.

Patches:

devlink rate changes for cross-device TX scheduling:
devlink: Reverse locking order for nested instances
documentation: networking: add shared devlink documentation
devlink: Add helpers to lock nested-in instances
devlink: Refactor devlink_rate_nodes_check
devlink: Decouple rate storage from associated devlink object
devlink: Add parent dev to devlink API
devlink: Allow parent dev for rate-set and rate-new
devlink: Allow rate node parents from other devlinks

mlx5 support for cross-devuce TX scheduling:
net/mlx5: Introduce shared devlink instance for PFs on same chip
net/mlx5: Expose a function to clear a vport's parent
net/mlx5: Store QoS sched nodes in the sh_devlink
net/mlx5: qos: Support cross-esw tx scheduling
net/mlx5: qos: Enable cross-device scheduling
net/mlx5: Document devlink rates and cross-esw scheduling

[2] https://lore.kernel.org/netdev/20250213180134.323929-1-tariqt@nvidia.com/


Cosmin Ratiu (12):
  devlink: Reverse locking order for nested instances
  devlink: Add helpers to lock nested-in instances
  devlink: Refactor devlink_rate_nodes_check
  devlink: Decouple rate storage from associated devlink object
  devlink: Add parent dev to devlink API
  devlink: Allow parent dev for rate-set and rate-new
  devlink: Allow rate node parents from other devlinks
  net/mlx5: Expose a function to clear a vport's parent
  net/mlx5: Store QoS sched nodes in the sh_devlink
  net/mlx5: qos: Support cross-device tx scheduling
  net/mlx5: qos: Enable cross-device scheduling
  net/mlx5: Document devlink rates

Jiri Pirko (2):
  documentation: networking: add shared devlink documentation
  net/mlx5: Introduce shared devlink instance for PFs on same chip

 Documentation/netlink/specs/devlink.yaml      |  22 +-
 .../networking/devlink/devlink-port.rst       |   2 +
 .../networking/devlink/devlink-shared.rst     |  66 ++++
 Documentation/networking/devlink/index.rst    |   3 +
 Documentation/networking/devlink/mlx5.rst     |  33 ++
 .../net/ethernet/mellanox/mlx5/core/Makefile  |   5 +-
 .../net/ethernet/mellanox/mlx5/core/devlink.c |   1 +
 .../mellanox/mlx5/core/esw/devlink_port.c     |   2 +-
 .../net/ethernet/mellanox/mlx5/core/esw/qos.c | 324 ++++++++----------
 .../net/ethernet/mellanox/mlx5/core/esw/qos.h |   3 -
 .../net/ethernet/mellanox/mlx5/core/eswitch.c |   9 +-
 .../net/ethernet/mellanox/mlx5/core/eswitch.h |  14 +-
 .../net/ethernet/mellanox/mlx5/core/main.c    |  18 +
 .../ethernet/mellanox/mlx5/core/sh_devlink.c  | 183 ++++++++++
 .../ethernet/mellanox/mlx5/core/sh_devlink.h  |  16 +
 include/linux/mlx5/driver.h                   |   5 +
 include/net/devlink.h                         |   7 +
 include/uapi/linux/devlink.h                  |   2 +
 net/devlink/core.c                            |  48 ++-
 net/devlink/dev.c                             |   7 +-
 net/devlink/devl_internal.h                   |  11 +-
 net/devlink/netlink.c                         |  67 +++-
 net/devlink/netlink_gen.c                     |  23 +-
 net/devlink/netlink_gen.h                     |   8 +
 net/devlink/rate.c                            | 287 ++++++++++++----
 25 files changed, 873 insertions(+), 293 deletions(-)
 create mode 100644 Documentation/networking/devlink/devlink-shared.rst
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.h

-- 
2.31.1

[PATCH net-next 01/14] devlink: Reverse locking order for nested instances

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

Commit [1] defined the locking expectations for nested devlink
instances: the nested-in devlink instance lock needs to be acquired
before the nested devlink instance lock. The code handling devlink rels
was architected with that assumption in mind.

There are no actual users of double locking yet but that is about to
change in the upcoming patches in the series.

Code operating on nested devlink instances will require also obtaining
the nested-in instance lock, but such code may already be called from a
variety of places with the nested devlink instance lock. Then, there's
no way to acquire the nested-in lock other than making sure that all
callers acquire it first.

Reversing the nested lock order allows incrementally acquiring the
nested-in instance lock when needed (perhaps even a chain of locks up to
the root) without affecting any caller.

The only affected use of nesting is devlink_nl_nested_fill(), which
iterates over nested devlink instances with the RCU lock, without
locking them, so there's no possibility of deadlock.

So this commit just updates a comment regarding the nested locks.

[1] commit c137743bce02b ("devlink: introduce object and nested devlink
relationship infra")

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 net/devlink/core.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/devlink/core.c b/net/devlink/core.c
index 58093f49c090..6ae62c7f2a80 100644
--- a/net/devlink/core.c
+++ b/net/devlink/core.c
@@ -178,9 +178,7 @@ int devlink_rel_nested_in_add(u32 *rel_index, u32 devlink_index,
  * a notification of a change of this object should be sent
  * over netlink. The parent devlink instance lock needs to be
  * taken during the notification preparation.
- * However, since the devlink lock of nested instance is held here,
- * we would end with wrong devlink instance lock ordering and
- * deadlock. Therefore the work is utilized to avoid that.
+ * Since the parent may or may not be locked, 'work' is utilized.
  */
 void devlink_rel_nested_in_notify(struct devlink *devlink)
 {
-- 
2.31.1

[PATCH net-next 02/14] documentation: networking: add shared devlink documentation

[Tariq Toukan]

From: Jiri Pirko <jiri@nvidia.com>

Document shared devlink instances for multiple PFs on the same chip.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../networking/devlink/devlink-shared.rst     | 66 +++++++++++++++++++
 Documentation/networking/devlink/index.rst    |  3 +
 2 files changed, 69 insertions(+)
 create mode 100644 Documentation/networking/devlink/devlink-shared.rst

diff --git a/Documentation/networking/devlink/devlink-shared.rst b/Documentation/networking/devlink/devlink-shared.rst
new file mode 100644
index 000000000000..8377d524998f
--- /dev/null
+++ b/Documentation/networking/devlink/devlink-shared.rst
@@ -0,0 +1,66 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================
+Devlink Shared Instances
+============================
+
+Overview
+========
+
+Shared devlink instances allow multiple physical functions (PFs) on the same
+chip to share an additional devlink instance for chip-wide operations. This
+should be implemented within individual drivers alongside the individual PF
+devlink instances, not replacing them.
+
+The shared devlink instance should be backed by a faux device and should
+provide a common interface for operations that affect the entire chip
+rather than individual PFs.
+
+Implementation
+==============
+
+Architecture
+------------
+
+The implementation should use:
+
+* **Faux device**: Virtual device backing the shared devlink instance
+* **Chip identification**: PFs are grouped by chip using a driver-specific identifier
+* **Shared instance management**: Global list of shared instances with reference counting
+
+Initialization Flow
+-------------------
+
+1. **PF calls shared devlink init** during driver probe
+2. **Chip identification** using driver-specific method to determine device identity
+3. **Lookup existing shared instance** for this chip identifier
+4. **Create new shared instance** if none exists:
+
+   * Create faux device with chip identifier as name
+   * Allocate and register devlink instance
+   * Add to global shared instances list
+
+5. **Add PF to shared instance** PF list
+6. **Set nested devlink instance** dor the PF devlink instance
+
+Cleanup Flow
+------------
+
+1. **Cleanup** when PF is removed; destroy shared instance when last PF is removed
+
+Chip Identification
+-------------------
+
+PFs belonging to the same chip are identified using a driver-specific method.
+The driver is free to choose any identifier that is suitable for determining
+whether two PFs are part of the same device. Examples include VPD serial numbers,
+device tree properties, or other hardware-specific identifiers.
+
+Locking
+-------
+
+A global per-driver mutex protects the shared instances list and individual shared
+instance PF lists during registration/deregistration.
+
+Similarly to other nested devlink instance relationships, devlink lock of
+the shared instance should be always taken after the devlink lock of PF.
diff --git a/Documentation/networking/devlink/index.rst b/Documentation/networking/devlink/index.rst
index 35b12a2bfeba..d14a764e9b1d 100644
--- a/Documentation/networking/devlink/index.rst
+++ b/Documentation/networking/devlink/index.rst
@@ -68,6 +68,9 @@ general.
    devlink-resource
    devlink-selftests
    devlink-trap
+   devlink-linecard
+   devlink-eswitch-attr
+   devlink-shared
 
 Driver-specific documentation
 -----------------------------
-- 
2.31.1

[PATCH net-next 03/14] devlink: Add helpers to lock nested-in instances

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

Upcoming code will need to obtain a reference to locked nested-in
devlink instances. Add helpers to lock, obtain an already locked
reference and unlock/unref the nested-in instance.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 net/devlink/core.c          | 42 +++++++++++++++++++++++++++++++++++++
 net/devlink/devl_internal.h |  3 +++
 2 files changed, 45 insertions(+)

diff --git a/net/devlink/core.c b/net/devlink/core.c
index 6ae62c7f2a80..f228190df346 100644
--- a/net/devlink/core.c
+++ b/net/devlink/core.c
@@ -67,6 +67,48 @@ static void __devlink_rel_put(struct devlink_rel *rel)
 		devlink_rel_free(rel);
 }
 
+struct devlink *devlink_nested_in_get_lock(struct devlink_rel *rel)
+{
+	struct devlink *devlink;
+
+	if (!rel)
+		return NULL;
+	devlink = devlinks_xa_get(rel->nested_in.devlink_index);
+	if (!devlink)
+		return NULL;
+	devl_lock(devlink);
+	if (devl_is_registered(devlink))
+		return devlink;
+	devl_unlock(devlink);
+	devlink_put(devlink);
+	return NULL;
+}
+
+/* Returns the nested in devlink object and validates its lock is held. */
+struct devlink *devlink_nested_in_get_locked(struct devlink_rel *rel)
+{
+	struct devlink *devlink;
+	unsigned long index;
+
+	if (!rel)
+		return NULL;
+	index = rel->nested_in.devlink_index;
+	devlink = xa_find(&devlinks, &index, index, DEVLINK_REGISTERED);
+	if (devlink)
+		devl_assert_locked(devlink);
+	return devlink;
+}
+
+void devlink_nested_in_put_unlock(struct devlink_rel *rel)
+{
+	struct devlink *devlink = devlink_nested_in_get_locked(rel);
+
+	if (devlink) {
+		devl_unlock(devlink);
+		devlink_put(devlink);
+	}
+}
+
 static void devlink_rel_nested_in_notify_work(struct work_struct *work)
 {
 	struct devlink_rel *rel = container_of(work, struct devlink_rel,
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 14eaad9cfe35..aea43d750d23 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -120,6 +120,9 @@ typedef void devlink_rel_notify_cb_t(struct devlink *devlink, u32 obj_index);
 typedef void devlink_rel_cleanup_cb_t(struct devlink *devlink, u32 obj_index,
 				      u32 rel_index);
 
+struct devlink *devlink_nested_in_get_lock(struct devlink_rel *rel);
+struct devlink *devlink_nested_in_get_locked(struct devlink_rel *rel);
+void devlink_nested_in_put_unlock(struct devlink_rel *rel);
 void devlink_rel_nested_in_clear(u32 rel_index);
 int devlink_rel_nested_in_add(u32 *rel_index, u32 devlink_index,
 			      u32 obj_index, devlink_rel_notify_cb_t *notify_cb,
-- 
2.31.1

Re: [PATCH net-next 03/14] devlink: Add helpers to lock nested-in instances

[Jiri Pirko]

Thu, Nov 20, 2025 at 02:09:15PM +0100, tariqt@nvidia.com wrote:
>From: Cosmin Ratiu <cratiu@nvidia.com>
>
>Upcoming code will need to obtain a reference to locked nested-in
>devlink instances. Add helpers to lock, obtain an already locked
>reference and unlock/unref the nested-in instance.
>
>Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
>Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
>Signed-off-by: Tariq Toukan <tariqt@nvidia.com>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

[PATCH net-next 04/14] devlink: Refactor devlink_rate_nodes_check

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

devlink_rate_nodes_check() was used to verify there are no devlink rate
nodes created when switching the esw mode.

Rate management code is about to become more complex, so refactor this
function:
- remove unused param 'mode'.
- add a new 'rate_filter' param.
- rename to devlink_rates_check().
- expose devlink_rate_is_node() to be used as a rate filter.

This makes it more usable from multiple places, so use it from those
places as well.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 net/devlink/core.c          |  2 +-
 net/devlink/dev.c           |  7 ++++---
 net/devlink/devl_internal.h |  6 ++++--
 net/devlink/rate.c          | 13 +++++++------
 4 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/net/devlink/core.c b/net/devlink/core.c
index f228190df346..f72d8cc0d6dd 100644
--- a/net/devlink/core.c
+++ b/net/devlink/core.c
@@ -517,7 +517,7 @@ void devlink_free(struct devlink *devlink)
 	WARN_ON(!list_empty(&devlink->resource_list));
 	WARN_ON(!list_empty(&devlink->dpipe_table_list));
 	WARN_ON(!list_empty(&devlink->sb_list));
-	WARN_ON(!list_empty(&devlink->rate_list));
+	WARN_ON(devlink_rates_check(devlink, NULL, NULL));
 	WARN_ON(!list_empty(&devlink->linecard_list));
 	WARN_ON(!xa_empty(&devlink->ports));
 
diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index 02602704bdea..e3a36de4f4ae 100644
--- a/net/devlink/dev.c
+++ b/net/devlink/dev.c
@@ -434,7 +434,7 @@ static void devlink_reload_reinit_sanity_check(struct devlink *devlink)
 	WARN_ON(!list_empty(&devlink->trap_list));
 	WARN_ON(!list_empty(&devlink->dpipe_table_list));
 	WARN_ON(!list_empty(&devlink->sb_list));
-	WARN_ON(!list_empty(&devlink->rate_list));
+	WARN_ON(devlink_rates_check(devlink, NULL, NULL));
 	WARN_ON(!list_empty(&devlink->linecard_list));
 	WARN_ON(!xa_empty(&devlink->ports));
 }
@@ -713,10 +713,11 @@ int devlink_nl_eswitch_set_doit(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[DEVLINK_ATTR_ESWITCH_MODE]) {
 		if (!ops->eswitch_mode_set)
 			return -EOPNOTSUPP;
-		mode = nla_get_u16(info->attrs[DEVLINK_ATTR_ESWITCH_MODE]);
-		err = devlink_rate_nodes_check(devlink, mode, info->extack);
+		err = devlink_rates_check(devlink, devlink_rate_is_node,
+					  info->extack);
 		if (err)
 			return err;
+		mode = nla_get_u16(info->attrs[DEVLINK_ATTR_ESWITCH_MODE]);
 		err = ops->eswitch_mode_set(devlink, mode, info->extack);
 		if (err)
 			return err;
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index aea43d750d23..8374c9cab6ce 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -300,8 +300,10 @@ int devlink_resources_validate(struct devlink *devlink,
 			       struct genl_info *info);
 
 /* Rates */
-int devlink_rate_nodes_check(struct devlink *devlink, u16 mode,
-			     struct netlink_ext_ack *extack);
+bool devlink_rate_is_node(const struct devlink_rate *devlink_rate);
+int devlink_rates_check(struct devlink *devlink,
+			bool (*rate_filter)(const struct devlink_rate *),
+			struct netlink_ext_ack *extack);
 
 /* Linecards */
 unsigned int devlink_linecard_index(struct devlink_linecard *linecard);
diff --git a/net/devlink/rate.c b/net/devlink/rate.c
index d157a8419bca..0d68b5c477dc 100644
--- a/net/devlink/rate.c
+++ b/net/devlink/rate.c
@@ -12,8 +12,7 @@ devlink_rate_is_leaf(struct devlink_rate *devlink_rate)
 	return devlink_rate->type == DEVLINK_RATE_TYPE_LEAF;
 }
 
-static inline bool
-devlink_rate_is_node(struct devlink_rate *devlink_rate)
+bool devlink_rate_is_node(const struct devlink_rate *devlink_rate)
 {
 	return devlink_rate->type == DEVLINK_RATE_TYPE_NODE;
 }
@@ -688,14 +687,16 @@ int devlink_nl_rate_del_doit(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
-int devlink_rate_nodes_check(struct devlink *devlink, u16 mode,
-			     struct netlink_ext_ack *extack)
+int devlink_rates_check(struct devlink *devlink,
+			bool (*rate_filter)(const struct devlink_rate *),
+			struct netlink_ext_ack *extack)
 {
 	struct devlink_rate *devlink_rate;
 
 	list_for_each_entry(devlink_rate, &devlink->rate_list, list)
-		if (devlink_rate_is_node(devlink_rate)) {
-			NL_SET_ERR_MSG(extack, "Rate node(s) exists.");
+		if (!rate_filter || rate_filter(devlink_rate)) {
+			if (extack)
+				NL_SET_ERR_MSG(extack, "Rate node(s) exists.");
 			return -EBUSY;
 		}
 	return 0;
-- 
2.31.1

Re: [PATCH net-next 04/14] devlink: Refactor devlink_rate_nodes_check

[Jiri Pirko]

Thu, Nov 20, 2025 at 02:09:16PM +0100, tariqt@nvidia.com wrote:
>From: Cosmin Ratiu <cratiu@nvidia.com>
>
>devlink_rate_nodes_check() was used to verify there are no devlink rate
>nodes created when switching the esw mode.
>
>Rate management code is about to become more complex, so refactor this
>function:
>- remove unused param 'mode'.
>- add a new 'rate_filter' param.
>- rename to devlink_rates_check().
>- expose devlink_rate_is_node() to be used as a rate filter.
>
>This makes it more usable from multiple places, so use it from those
>places as well.
>
>Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
>Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
>Signed-off-by: Tariq Toukan <tariqt@nvidia.com>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

[PATCH net-next 05/14] devlink: Decouple rate storage from associated devlink object

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

Devlink rate leafs and nodes were stored in their respective devlink
objects pointed to by devlink_rate->devlink.

This patch removes that association by introducing the concept of
'rate node devlink', which is where all rates that could link to each
other are stored. For now this is the same as devlink_rate->devlink.

After this patch, the devlink rates stored in this devlink instance
could potentially be from multiple other devlink instances. So all rate
node manipulation code was updated to:
- correctly compare the actual devlink object during iteration.
- maybe acquire additional locks (noop for now).

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 include/net/devlink.h |   2 +
 net/devlink/rate.c    | 192 +++++++++++++++++++++++++++++++-----------
 2 files changed, 144 insertions(+), 50 deletions(-)

diff --git a/include/net/devlink.h b/include/net/devlink.h
index d01046ef0577..7e7789098f0e 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1771,6 +1771,8 @@ void devlink_port_attrs_pci_sf_set(struct devlink_port *devlink_port,
 				   bool external);
 int devl_port_fn_devlink_set(struct devlink_port *devlink_port,
 			     struct devlink *fn_devlink);
+struct devlink *devl_rate_lock(struct devlink *devlink);
+void devl_rate_unlock(struct devlink *devlink);
 struct devlink_rate *
 devl_rate_node_create(struct devlink *devlink, void *priv, char *node_name,
 		      struct devlink_rate *parent);
diff --git a/net/devlink/rate.c b/net/devlink/rate.c
index 0d68b5c477dc..ddbd0beec4b9 100644
--- a/net/devlink/rate.c
+++ b/net/devlink/rate.c
@@ -30,13 +30,31 @@ devlink_rate_leaf_get_from_info(struct devlink *devlink, struct genl_info *info)
 	return devlink_rate ?: ERR_PTR(-ENODEV);
 }
 
+struct devlink *devl_rate_lock(struct devlink *devlink)
+{
+	return devlink;
+}
+
+static struct devlink *
+devl_get_rate_node_instance_locked(struct devlink *devlink)
+{
+	return devlink;
+}
+
+void devl_rate_unlock(struct devlink *devlink)
+{
+}
+
 static struct devlink_rate *
 devlink_rate_node_get_by_name(struct devlink *devlink, const char *node_name)
 {
 	struct devlink_rate *devlink_rate;
+	struct devlink *rate_devlink;
 
-	list_for_each_entry(devlink_rate, &devlink->rate_list, list) {
-		if (devlink_rate_is_node(devlink_rate) &&
+	rate_devlink = devl_get_rate_node_instance_locked(devlink);
+	list_for_each_entry(devlink_rate, &rate_devlink->rate_list, list) {
+		if (devlink_rate->devlink == devlink &&
+		    devlink_rate_is_node(devlink_rate) &&
 		    !strcmp(node_name, devlink_rate->name))
 			return devlink_rate;
 	}
@@ -190,17 +208,25 @@ static void devlink_rate_notify(struct devlink_rate *devlink_rate,
 void devlink_rates_notify_register(struct devlink *devlink)
 {
 	struct devlink_rate *rate_node;
+	struct devlink *rate_devlink;
 
-	list_for_each_entry(rate_node, &devlink->rate_list, list)
-		devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_NEW);
+	rate_devlink = devl_rate_lock(devlink);
+	list_for_each_entry(rate_node, &rate_devlink->rate_list, list)
+		if (rate_node->devlink == devlink)
+			devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_NEW);
+	devl_rate_unlock(devlink);
 }
 
 void devlink_rates_notify_unregister(struct devlink *devlink)
 {
 	struct devlink_rate *rate_node;
+	struct devlink *rate_devlink;
 
-	list_for_each_entry_reverse(rate_node, &devlink->rate_list, list)
-		devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_DEL);
+	rate_devlink = devl_rate_lock(devlink);
+	list_for_each_entry_reverse(rate_node, &rate_devlink->rate_list, list)
+		if (rate_node->devlink == devlink)
+			devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_DEL);
+	devl_rate_unlock(devlink);
 }
 
 static int
@@ -209,10 +235,12 @@ devlink_nl_rate_get_dump_one(struct sk_buff *msg, struct devlink *devlink,
 {
 	struct devlink_nl_dump_state *state = devlink_dump_state(cb);
 	struct devlink_rate *devlink_rate;
+	struct devlink *rate_devlink;
 	int idx = 0;
 	int err = 0;
 
-	list_for_each_entry(devlink_rate, &devlink->rate_list, list) {
+	rate_devlink = devl_rate_lock(devlink);
+	list_for_each_entry(devlink_rate, &rate_devlink->rate_list, list) {
 		enum devlink_command cmd = DEVLINK_CMD_RATE_NEW;
 		u32 id = NETLINK_CB(cb->skb).portid;
 
@@ -220,6 +248,9 @@ devlink_nl_rate_get_dump_one(struct sk_buff *msg, struct devlink *devlink,
 			idx++;
 			continue;
 		}
+		if (devlink_rate->devlink != devlink)
+			continue;
+
 		err = devlink_nl_rate_fill(msg, devlink_rate, cmd, id,
 					   cb->nlh->nlmsg_seq, flags, NULL);
 		if (err) {
@@ -228,6 +259,7 @@ devlink_nl_rate_get_dump_one(struct sk_buff *msg, struct devlink *devlink,
 		}
 		idx++;
 	}
+	devl_rate_unlock(devlink);
 
 	return err;
 }
@@ -244,23 +276,33 @@ int devlink_nl_rate_get_doit(struct sk_buff *skb, struct genl_info *info)
 	struct sk_buff *msg;
 	int err;
 
+	devl_rate_lock(devlink);
 	devlink_rate = devlink_rate_get_from_info(devlink, info);
-	if (IS_ERR(devlink_rate))
-		return PTR_ERR(devlink_rate);
+	if (IS_ERR(devlink_rate)) {
+		err = PTR_ERR(devlink_rate);
+		goto unlock;
+	}
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-	if (!msg)
-		return -ENOMEM;
+	if (!msg) {
+		err = -ENOMEM;
+		goto unlock;
+	}
 
 	err = devlink_nl_rate_fill(msg, devlink_rate, DEVLINK_CMD_RATE_NEW,
 				   info->snd_portid, info->snd_seq, 0,
 				   info->extack);
-	if (err) {
-		nlmsg_free(msg);
-		return err;
-	}
+	if (err)
+		goto err_fill;
 
+	devl_rate_unlock(devlink);
 	return genlmsg_reply(msg, info);
+
+err_fill:
+	nlmsg_free(msg);
+unlock:
+	devl_rate_unlock(devlink);
+	return err;
 }
 
 static bool
@@ -590,24 +632,32 @@ int devlink_nl_rate_set_doit(struct sk_buff *skb, struct genl_info *info)
 	const struct devlink_ops *ops;
 	int err;
 
+	devl_rate_lock(devlink);
 	devlink_rate = devlink_rate_get_from_info(devlink, info);
-	if (IS_ERR(devlink_rate))
-		return PTR_ERR(devlink_rate);
+	if (IS_ERR(devlink_rate)) {
+		err = PTR_ERR(devlink_rate);
+		goto unlock;
+	}
 
 	ops = devlink->ops;
-	if (!ops || !devlink_rate_set_ops_supported(ops, info, devlink_rate->type))
-		return -EOPNOTSUPP;
+	if (!ops ||
+	    !devlink_rate_set_ops_supported(ops, info, devlink_rate->type)) {
+		err = -EOPNOTSUPP;
+		goto unlock;
+	}
 
 	err = devlink_nl_rate_set(devlink_rate, ops, info);
 
 	if (!err)
 		devlink_rate_notify(devlink_rate, DEVLINK_CMD_RATE_NEW);
+unlock:
+	devl_rate_unlock(devlink);
 	return err;
 }
 
 int devlink_nl_rate_new_doit(struct sk_buff *skb, struct genl_info *info)
 {
-	struct devlink *devlink = info->user_ptr[0];
+	struct devlink *rate_devlink, *devlink = info->user_ptr[0];
 	struct devlink_rate *rate_node;
 	const struct devlink_ops *ops;
 	int err;
@@ -621,15 +671,21 @@ int devlink_nl_rate_new_doit(struct sk_buff *skb, struct genl_info *info)
 	if (!devlink_rate_set_ops_supported(ops, info, DEVLINK_RATE_TYPE_NODE))
 		return -EOPNOTSUPP;
 
+	rate_devlink = devl_rate_lock(devlink);
 	rate_node = devlink_rate_node_get_from_attrs(devlink, info->attrs);
-	if (!IS_ERR(rate_node))
-		return -EEXIST;
-	else if (rate_node == ERR_PTR(-EINVAL))
-		return -EINVAL;
+	if (!IS_ERR(rate_node)) {
+		err = -EEXIST;
+		goto unlock;
+	} else if (rate_node == ERR_PTR(-EINVAL)) {
+		err = -EINVAL;
+		goto unlock;
+	}
 
 	rate_node = kzalloc(sizeof(*rate_node), GFP_KERNEL);
-	if (!rate_node)
-		return -ENOMEM;
+	if (!rate_node) {
+		err = -ENOMEM;
+		goto unlock;
+	}
 
 	rate_node->devlink = devlink;
 	rate_node->type = DEVLINK_RATE_TYPE_NODE;
@@ -648,8 +704,9 @@ int devlink_nl_rate_new_doit(struct sk_buff *skb, struct genl_info *info)
 		goto err_rate_set;
 
 	refcount_set(&rate_node->refcnt, 1);
-	list_add(&rate_node->list, &devlink->rate_list);
+	list_add(&rate_node->list, &rate_devlink->rate_list);
 	devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_NEW);
+	devl_rate_unlock(devlink);
 	return 0;
 
 err_rate_set:
@@ -658,6 +715,8 @@ int devlink_nl_rate_new_doit(struct sk_buff *skb, struct genl_info *info)
 	kfree(rate_node->name);
 err_strdup:
 	kfree(rate_node);
+unlock:
+	devl_rate_unlock(devlink);
 	return err;
 }
 
@@ -667,13 +726,17 @@ int devlink_nl_rate_del_doit(struct sk_buff *skb, struct genl_info *info)
 	struct devlink_rate *rate_node;
 	int err;
 
+	devl_rate_lock(devlink);
 	rate_node = devlink_rate_node_get_from_info(devlink, info);
-	if (IS_ERR(rate_node))
-		return PTR_ERR(rate_node);
+	if (IS_ERR(rate_node)) {
+		err = PTR_ERR(rate_node);
+		goto unlock;
+	}
 
 	if (refcount_read(&rate_node->refcnt) > 1) {
 		NL_SET_ERR_MSG(info->extack, "Node has children. Cannot delete node.");
-		return -EBUSY;
+		err = -EBUSY;
+		goto unlock;
 	}
 
 	devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_DEL);
@@ -684,6 +747,8 @@ int devlink_nl_rate_del_doit(struct sk_buff *skb, struct genl_info *info)
 	list_del(&rate_node->list);
 	kfree(rate_node->name);
 	kfree(rate_node);
+unlock:
+	devl_rate_unlock(devlink);
 	return err;
 }
 
@@ -692,14 +757,20 @@ int devlink_rates_check(struct devlink *devlink,
 			struct netlink_ext_ack *extack)
 {
 	struct devlink_rate *devlink_rate;
+	struct devlink *rate_devlink;
+	int err = 0;
 
-	list_for_each_entry(devlink_rate, &devlink->rate_list, list)
-		if (!rate_filter || rate_filter(devlink_rate)) {
+	rate_devlink = devl_rate_lock(devlink);
+	list_for_each_entry(devlink_rate, &rate_devlink->rate_list, list)
+		if (devlink_rate->devlink == devlink &&
+		    (!rate_filter || rate_filter(devlink_rate))) {
 			if (extack)
 				NL_SET_ERR_MSG(extack, "Rate node(s) exists.");
-			return -EBUSY;
+			err = -EBUSY;
+			break;
 		}
-	return 0;
+	devl_rate_unlock(devlink);
+	return err;
 }
 
 /**
@@ -716,14 +787,20 @@ devl_rate_node_create(struct devlink *devlink, void *priv, char *node_name,
 		      struct devlink_rate *parent)
 {
 	struct devlink_rate *rate_node;
+	struct devlink *rate_devlink;
 
+	rate_devlink = devl_rate_lock(devlink);
 	rate_node = devlink_rate_node_get_by_name(devlink, node_name);
-	if (!IS_ERR(rate_node))
-		return ERR_PTR(-EEXIST);
+	if (!IS_ERR(rate_node)) {
+		rate_node = ERR_PTR(-EEXIST);
+		goto unlock;
+	}
 
 	rate_node = kzalloc(sizeof(*rate_node), GFP_KERNEL);
-	if (!rate_node)
-		return ERR_PTR(-ENOMEM);
+	if (!rate_node) {
+		rate_node = ERR_PTR(-ENOMEM);
+		goto unlock;
+	}
 
 	if (parent) {
 		rate_node->parent = parent;
@@ -737,12 +814,15 @@ devl_rate_node_create(struct devlink *devlink, void *priv, char *node_name,
 	rate_node->name = kstrdup(node_name, GFP_KERNEL);
 	if (!rate_node->name) {
 		kfree(rate_node);
-		return ERR_PTR(-ENOMEM);
+		rate_node = ERR_PTR(-ENOMEM);
+		goto unlock;
 	}
 
 	refcount_set(&rate_node->refcnt, 1);
-	list_add(&rate_node->list, &devlink->rate_list);
+	list_add(&rate_node->list, &rate_devlink->rate_list);
 	devlink_rate_notify(rate_node, DEVLINK_CMD_RATE_NEW);
+unlock:
+	devl_rate_unlock(devlink);
 	return rate_node;
 }
 EXPORT_SYMBOL_GPL(devl_rate_node_create);
@@ -758,10 +838,10 @@ EXPORT_SYMBOL_GPL(devl_rate_node_create);
 int devl_rate_leaf_create(struct devlink_port *devlink_port, void *priv,
 			  struct devlink_rate *parent)
 {
-	struct devlink *devlink = devlink_port->devlink;
+	struct devlink *rate_devlink, *devlink = devlink_port->devlink;
 	struct devlink_rate *devlink_rate;
 
-	devl_assert_locked(devlink_port->devlink);
+	devl_assert_locked(devlink);
 
 	if (WARN_ON(devlink_port->devlink_rate))
 		return -EBUSY;
@@ -770,6 +850,7 @@ int devl_rate_leaf_create(struct devlink_port *devlink_port, void *priv,
 	if (!devlink_rate)
 		return -ENOMEM;
 
+	rate_devlink = devl_rate_lock(devlink);
 	if (parent) {
 		devlink_rate->parent = parent;
 		refcount_inc(&devlink_rate->parent->refcnt);
@@ -779,9 +860,10 @@ int devl_rate_leaf_create(struct devlink_port *devlink_port, void *priv,
 	devlink_rate->devlink = devlink;
 	devlink_rate->devlink_port = devlink_port;
 	devlink_rate->priv = priv;
-	list_add_tail(&devlink_rate->list, &devlink->rate_list);
+	list_add_tail(&devlink_rate->list, &rate_devlink->rate_list);
 	devlink_port->devlink_rate = devlink_rate;
 	devlink_rate_notify(devlink_rate, DEVLINK_CMD_RATE_NEW);
+	devl_rate_unlock(devlink);
 
 	return 0;
 }
@@ -797,16 +879,19 @@ EXPORT_SYMBOL_GPL(devl_rate_leaf_create);
 void devl_rate_leaf_destroy(struct devlink_port *devlink_port)
 {
 	struct devlink_rate *devlink_rate = devlink_port->devlink_rate;
+	struct devlink *devlink = devlink_port->devlink;
 
-	devl_assert_locked(devlink_port->devlink);
+	devl_assert_locked(devlink);
 	if (!devlink_rate)
 		return;
 
+	devl_rate_lock(devlink);
 	devlink_rate_notify(devlink_rate, DEVLINK_CMD_RATE_DEL);
 	if (devlink_rate->parent)
 		refcount_dec(&devlink_rate->parent->refcnt);
 	list_del(&devlink_rate->list);
 	devlink_port->devlink_rate = NULL;
+	devl_rate_unlock(devlink);
 	kfree(devlink_rate);
 }
 EXPORT_SYMBOL_GPL(devl_rate_leaf_destroy);
@@ -815,18 +900,22 @@ EXPORT_SYMBOL_GPL(devl_rate_leaf_destroy);
  * devl_rate_nodes_destroy - destroy all devlink rate nodes on device
  * @devlink: devlink instance
  *
- * Unset parent for all rate objects and destroy all rate nodes
- * on specified device.
+ * Unset parent for all rate objects involving this device and destroy all rate
+ * nodes on it.
  */
 void devl_rate_nodes_destroy(struct devlink *devlink)
 {
 	const struct devlink_ops *ops = devlink->ops;
 	struct devlink_rate *devlink_rate, *tmp;
+	struct devlink *rate_devlink;
 
 	devl_assert_locked(devlink);
+	rate_devlink = devl_rate_lock(devlink);
 
-	list_for_each_entry(devlink_rate, &devlink->rate_list, list) {
-		if (!devlink_rate->parent)
+	list_for_each_entry(devlink_rate, &rate_devlink->rate_list, list) {
+		if (!devlink_rate->parent ||
+		    (devlink_rate->devlink != devlink &&
+		     devlink_rate->parent->devlink != devlink))
 			continue;
 
 		if (devlink_rate_is_leaf(devlink_rate))
@@ -839,13 +928,16 @@ void devl_rate_nodes_destroy(struct devlink *devlink)
 		refcount_dec(&devlink_rate->parent->refcnt);
 		devlink_rate->parent = NULL;
 	}
-	list_for_each_entry_safe(devlink_rate, tmp, &devlink->rate_list, list) {
-		if (devlink_rate_is_node(devlink_rate)) {
+	list_for_each_entry_safe(devlink_rate, tmp, &rate_devlink->rate_list,
+				 list) {
+		if (devlink_rate->devlink == devlink &&
+		    devlink_rate_is_node(devlink_rate)) {
 			ops->rate_node_del(devlink_rate, devlink_rate->priv, NULL);
 			list_del(&devlink_rate->list);
 			kfree(devlink_rate->name);
 			kfree(devlink_rate);
 		}
 	}
+	devl_rate_unlock(devlink);
 }
 EXPORT_SYMBOL_GPL(devl_rate_nodes_destroy);
-- 
2.31.1

Re: [PATCH net-next 05/14] devlink: Decouple rate storage from associated devlink object

[Jiri Pirko]

Thu, Nov 20, 2025 at 02:09:17PM +0100, tariqt@nvidia.com wrote:
>From: Cosmin Ratiu <cratiu@nvidia.com>
>
>Devlink rate leafs and nodes were stored in their respective devlink
>objects pointed to by devlink_rate->devlink.
>
>This patch removes that association by introducing the concept of
>'rate node devlink', which is where all rates that could link to each
>other are stored. For now this is the same as devlink_rate->devlink.
>
>After this patch, the devlink rates stored in this devlink instance
>could potentially be from multiple other devlink instances. So all rate
>node manipulation code was updated to:
>- correctly compare the actual devlink object during iteration.
>- maybe acquire additional locks (noop for now).
>
>Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
>Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
>Signed-off-by: Tariq Toukan <tariqt@nvidia.com>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

[PATCH net-next 06/14] devlink: Add parent dev to devlink API

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

Upcoming changes to the rate commands need the parent devlink specified.
This change adds a nested 'parent-dev' attribute to the API and helpers
to obtain and put a reference to the parent devlink instance in
info->user_ptr[1].

To avoid deadlocks, the parent devlink is unlocked before obtaining the
main devlink instance that is the target of the request.
A reference to the parent is kept until the end of the request to avoid
it suddenly disappearing.

This means that this reference is of limited use without additional
protection.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 Documentation/netlink/specs/devlink.yaml | 12 +++++
 include/uapi/linux/devlink.h             |  2 +
 net/devlink/devl_internal.h              |  2 +
 net/devlink/netlink.c                    | 67 ++++++++++++++++++++++--
 net/devlink/netlink_gen.c                |  5 ++
 net/devlink/netlink_gen.h                |  8 +++
 6 files changed, 91 insertions(+), 5 deletions(-)

diff --git a/Documentation/netlink/specs/devlink.yaml b/Documentation/netlink/specs/devlink.yaml
index 426d5aa7d955..fe49acd2b271 100644
--- a/Documentation/netlink/specs/devlink.yaml
+++ b/Documentation/netlink/specs/devlink.yaml
@@ -859,6 +859,10 @@ attribute-sets:
         name: health-reporter-burst-period
         type: u64
         doc: Time (in msec) for recoveries before starting the grace period.
+
+      - name: parent-dev
+        type: nest
+        nested-attributes: dl-parent-dev
   -
     name: dl-dev-stats
     subset-of: devlink
@@ -1281,6 +1285,14 @@ attribute-sets:
              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-parent-dev
+    subset-of: devlink
+    attributes:
+      -
+        name: bus-name
+      -
+        name: dev-name
 
 operations:
   enum-model: directional
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 157f11d3fb72..1744235c3d15 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -639,6 +639,8 @@ enum devlink_attr {
 
 	DEVLINK_ATTR_HEALTH_REPORTER_BURST_PERIOD,	/* u64 */
 
+	DEVLINK_ATTR_PARENT_DEV,		/* nested */
+
 	/* Add new attributes above here, update the spec in
 	 * Documentation/netlink/specs/devlink.yaml and re-generate
 	 * net/devlink/netlink_gen.c.
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 8374c9cab6ce..3ca4cc8517cd 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -162,6 +162,8 @@ typedef int devlink_nl_dump_one_func_t(struct sk_buff *msg,
 struct devlink *
 devlink_get_from_attrs_lock(struct net *net, struct nlattr **attrs,
 			    bool dev_lock);
+struct devlink *
+devlink_get_parent_from_attrs_lock(struct net *net, struct nlattr **attrs);
 
 int devlink_nl_dumpit(struct sk_buff *msg, struct netlink_callback *cb,
 		      devlink_nl_dump_one_func_t *dump_one);
diff --git a/net/devlink/netlink.c b/net/devlink/netlink.c
index 593605c1b1ef..781758b8632c 100644
--- a/net/devlink/netlink.c
+++ b/net/devlink/netlink.c
@@ -12,6 +12,7 @@
 #define DEVLINK_NL_FLAG_NEED_PORT		BIT(0)
 #define DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT	BIT(1)
 #define DEVLINK_NL_FLAG_NEED_DEV_LOCK		BIT(2)
+#define DEVLINK_NL_FLAG_OPTIONAL_PARENT_DEV	BIT(3)
 
 static const struct genl_multicast_group devlink_nl_mcgrps[] = {
 	[DEVLINK_MCGRP_CONFIG] = { .name = DEVLINK_GENL_MCGRP_CONFIG_NAME },
@@ -206,19 +207,51 @@ devlink_get_from_attrs_lock(struct net *net, struct nlattr **attrs,
 	return ERR_PTR(-ENODEV);
 }
 
+struct devlink *
+devlink_get_parent_from_attrs_lock(struct net *net, struct nlattr **attrs)
+{
+	struct nlattr *tb[DEVLINK_ATTR_DEV_NAME + 1];
+	int err;
+
+	if (!attrs[DEVLINK_ATTR_PARENT_DEV])
+		return ERR_PTR(-EINVAL);
+
+	err = nla_parse_nested(tb, DEVLINK_ATTR_DEV_NAME,
+			       attrs[DEVLINK_ATTR_PARENT_DEV],
+			       devlink_dl_parent_dev_nl_policy, NULL);
+	if (err)
+		return ERR_PTR(err);
+
+	return devlink_get_from_attrs_lock(net, tb, false);
+}
+
 static int __devlink_nl_pre_doit(struct sk_buff *skb, struct genl_info *info,
 				 u8 flags)
 {
+	bool parent_dev = flags & DEVLINK_NL_FLAG_OPTIONAL_PARENT_DEV;
 	bool dev_lock = flags & DEVLINK_NL_FLAG_NEED_DEV_LOCK;
+	struct devlink *devlink, *parent_devlink = NULL;
+	struct net *net = genl_info_net(info);
+	struct nlattr **attrs = info->attrs;
 	struct devlink_port *devlink_port;
-	struct devlink *devlink;
 	int err;
 
-	devlink = devlink_get_from_attrs_lock(genl_info_net(info), info->attrs,
-					      dev_lock);
-	if (IS_ERR(devlink))
-		return PTR_ERR(devlink);
+	if (parent_dev && attrs[DEVLINK_ATTR_PARENT_DEV]) {
+		parent_devlink = devlink_get_parent_from_attrs_lock(net, attrs);
+		if (IS_ERR(parent_devlink))
+			return PTR_ERR(parent_devlink);
+		info->user_ptr[1] = parent_devlink;
+		/* Drop the parent devlink lock but don't release the reference.
+		 * This will keep it alive until the end of the request.
+		 */
+		devl_unlock(parent_devlink);
+	}
 
+	devlink = devlink_get_from_attrs_lock(net, attrs, dev_lock);
+	if (IS_ERR(devlink)) {
+		err = PTR_ERR(devlink);
+		goto parent_put;
+	}
 	info->user_ptr[0] = devlink;
 	if (flags & DEVLINK_NL_FLAG_NEED_PORT) {
 		devlink_port = devlink_port_get_from_info(devlink, info);
@@ -237,6 +270,9 @@ static int __devlink_nl_pre_doit(struct sk_buff *skb, struct genl_info *info,
 unlock:
 	devl_dev_unlock(devlink, dev_lock);
 	devlink_put(devlink);
+parent_put:
+	if (parent_dev && parent_devlink)
+		devlink_put(parent_devlink);
 	return err;
 }
 
@@ -265,6 +301,14 @@ int devlink_nl_pre_doit_port_optional(const struct genl_split_ops *ops,
 	return __devlink_nl_pre_doit(skb, info, DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT);
 }
 
+int devlink_nl_pre_doit_parent_dev_optional(const struct genl_split_ops *ops,
+					    struct sk_buff *skb,
+					    struct genl_info *info)
+{
+	return __devlink_nl_pre_doit(skb, info,
+				     DEVLINK_NL_FLAG_OPTIONAL_PARENT_DEV);
+}
+
 static void __devlink_nl_post_doit(struct sk_buff *skb, struct genl_info *info,
 				   u8 flags)
 {
@@ -274,6 +318,11 @@ static void __devlink_nl_post_doit(struct sk_buff *skb, struct genl_info *info,
 	devlink = info->user_ptr[0];
 	devl_dev_unlock(devlink, dev_lock);
 	devlink_put(devlink);
+	if ((flags & DEVLINK_NL_FLAG_OPTIONAL_PARENT_DEV) &&
+	    info->user_ptr[1]) {
+		devlink = info->user_ptr[1];
+		devlink_put(devlink);
+	}
 }
 
 void devlink_nl_post_doit(const struct genl_split_ops *ops,
@@ -289,6 +338,14 @@ devlink_nl_post_doit_dev_lock(const struct genl_split_ops *ops,
 	__devlink_nl_post_doit(skb, info, DEVLINK_NL_FLAG_NEED_DEV_LOCK);
 }
 
+void
+devlink_nl_post_doit_parent_dev_optional(const struct genl_split_ops *ops,
+					 struct sk_buff *skb,
+					 struct genl_info *info)
+{
+	__devlink_nl_post_doit(skb, info, DEVLINK_NL_FLAG_OPTIONAL_PARENT_DEV);
+}
+
 static int devlink_nl_inst_single_dumpit(struct sk_buff *msg,
 					 struct netlink_callback *cb, int flags,
 					 devlink_nl_dump_one_func_t *dump_one,
diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
index 5ad435aee29d..3cabbc1207f2 100644
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@@ -38,6 +38,11 @@ devlink_attr_param_type_validate(const struct nlattr *attr,
 }
 
 /* Common nested types */
+const struct nla_policy devlink_dl_parent_dev_nl_policy[DEVLINK_ATTR_DEV_NAME + 1] = {
+	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
+	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
+};
+
 const struct nla_policy devlink_dl_port_function_nl_policy[DEVLINK_PORT_FN_ATTR_CAPS + 1] = {
 	[DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR] = { .type = NLA_BINARY, },
 	[DEVLINK_PORT_FN_ATTR_STATE] = NLA_POLICY_MAX(NLA_U8, 1),
diff --git a/net/devlink/netlink_gen.h b/net/devlink/netlink_gen.h
index 09cc6f264ccf..94566cab1734 100644
--- a/net/devlink/netlink_gen.h
+++ b/net/devlink/netlink_gen.h
@@ -12,6 +12,7 @@
 #include <uapi/linux/devlink.h>
 
 /* Common nested types */
+extern const struct nla_policy devlink_dl_parent_dev_nl_policy[DEVLINK_ATTR_DEV_NAME + 1];
 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_RATE_TC_ATTR_BW + 1];
 extern const struct nla_policy devlink_dl_selftest_id_nl_policy[DEVLINK_ATTR_SELFTEST_ID_FLASH + 1];
@@ -28,12 +29,19 @@ int devlink_nl_pre_doit_dev_lock(const struct genl_split_ops *ops,
 int devlink_nl_pre_doit_port_optional(const struct genl_split_ops *ops,
 				      struct sk_buff *skb,
 				      struct genl_info *info);
+int devlink_nl_pre_doit_parent_dev_optional(const struct genl_split_ops *ops,
+					    struct sk_buff *skb,
+					    struct genl_info *info);
 void
 devlink_nl_post_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
 		     struct genl_info *info);
 void
 devlink_nl_post_doit_dev_lock(const struct genl_split_ops *ops,
 			      struct sk_buff *skb, struct genl_info *info);
+void
+devlink_nl_post_doit_parent_dev_optional(const struct genl_split_ops *ops,
+					 struct sk_buff *skb,
+					 struct genl_info *info);
 
 int devlink_nl_get_doit(struct sk_buff *skb, struct genl_info *info);
 int devlink_nl_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
-- 
2.31.1

[PATCH net-next 07/14] devlink: Allow parent dev for rate-set and rate-new

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

Currently, a devlink rate's parent device is assumed to be the same as
the one where the devlink rate is created.

This patch changes that to allow rate commands to accept an additional
argument that specifies the parent dev. This will allow devlink rate
groups with leafs from other devices.

Example of the new usage with ynl:

Creating a group on pci/0000:08:00.1 with a parent to an already
existing pci/0000:08:00.1/group1:
./tools/net/ynl/pyynl/cli.py --spec \
Documentation/netlink/specs/devlink.yaml --do rate-new --json '{
    "bus-name": "pci",
    "dev-name": "0000:08:00.1",
    "rate-node-name": "group2",
    "rate-parent-node-name": "group1",
    "parent-dev": {
        "bus-name": "pci",
        "dev-name": "0000:08:00.1"
    }
  }'

Setting the parent of leaf node pci/0000:08:00.1/65537 to
pci/0000:08:00.0/group1:
./tools/net/ynl/pyynl/cli.py --spec \
Documentation/netlink/specs/devlink.yaml --do rate-set --json '{
    "bus-name": "pci",
    "dev-name": "0000:08:00.1",
    "port-index": 65537,
    "parent-dev": {
        "bus-name": "pci",
        "dev-name": "0000:08:00.0"
    },
    "rate-parent-node-name": "group1"
  }'

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 Documentation/netlink/specs/devlink.yaml | 10 ++++++----
 net/devlink/netlink_gen.c                | 18 ++++++++++--------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/Documentation/netlink/specs/devlink.yaml b/Documentation/netlink/specs/devlink.yaml
index fe49acd2b271..9c55e6ae9547 100644
--- a/Documentation/netlink/specs/devlink.yaml
+++ b/Documentation/netlink/specs/devlink.yaml
@@ -2209,8 +2209,8 @@ operations:
       dont-validate: [strict]
       flags: [admin-perm]
       do:
-        pre: devlink-nl-pre-doit
-        post: devlink-nl-post-doit
+        pre: devlink-nl-pre-doit-parent-dev-optional
+        post: devlink-nl-post-doit-parent-dev-optional
         request:
           attributes:
             - bus-name
@@ -2222,6 +2222,7 @@ operations:
             - rate-tx-weight
             - rate-parent-node-name
             - rate-tc-bws
+            - parent-dev
 
     -
       name: rate-new
@@ -2230,8 +2231,8 @@ operations:
       dont-validate: [strict]
       flags: [admin-perm]
       do:
-        pre: devlink-nl-pre-doit
-        post: devlink-nl-post-doit
+        pre: devlink-nl-pre-doit-parent-dev-optional
+        post: devlink-nl-post-doit-parent-dev-optional
         request:
           attributes:
             - bus-name
@@ -2243,6 +2244,7 @@ operations:
             - rate-tx-weight
             - rate-parent-node-name
             - rate-tc-bws
+            - parent-dev
 
     -
       name: rate-del
diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
index 3cabbc1207f2..73a6441da7a2 100644
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@@ -534,7 +534,7 @@ 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_TC_BWS + 1] = {
+static const struct nla_policy devlink_rate_set_nl_policy[DEVLINK_ATTR_PARENT_DEV + 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, },
@@ -544,10 +544,11 @@ static const struct nla_policy devlink_rate_set_nl_policy[DEVLINK_ATTR_RATE_TC_B
 	[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_ATTR_PARENT_DEV] = NLA_POLICY_NESTED(devlink_dl_parent_dev_nl_policy),
 };
 
 /* DEVLINK_CMD_RATE_NEW - do */
-static const struct nla_policy devlink_rate_new_nl_policy[DEVLINK_ATTR_RATE_TC_BWS + 1] = {
+static const struct nla_policy devlink_rate_new_nl_policy[DEVLINK_ATTR_PARENT_DEV + 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, },
@@ -557,6 +558,7 @@ static const struct nla_policy devlink_rate_new_nl_policy[DEVLINK_ATTR_RATE_TC_B
 	[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_ATTR_PARENT_DEV] = NLA_POLICY_NESTED(devlink_dl_parent_dev_nl_policy),
 };
 
 /* DEVLINK_CMD_RATE_DEL - do */
@@ -1200,21 +1202,21 @@ const struct genl_split_ops devlink_nl_ops[74] = {
 	{
 		.cmd		= DEVLINK_CMD_RATE_SET,
 		.validate	= GENL_DONT_VALIDATE_STRICT,
-		.pre_doit	= devlink_nl_pre_doit,
+		.pre_doit	= devlink_nl_pre_doit_parent_dev_optional,
 		.doit		= devlink_nl_rate_set_doit,
-		.post_doit	= devlink_nl_post_doit,
+		.post_doit	= devlink_nl_post_doit_parent_dev_optional,
 		.policy		= devlink_rate_set_nl_policy,
-		.maxattr	= DEVLINK_ATTR_RATE_TC_BWS,
+		.maxattr	= DEVLINK_ATTR_PARENT_DEV,
 		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
 	},
 	{
 		.cmd		= DEVLINK_CMD_RATE_NEW,
 		.validate	= GENL_DONT_VALIDATE_STRICT,
-		.pre_doit	= devlink_nl_pre_doit,
+		.pre_doit	= devlink_nl_pre_doit_parent_dev_optional,
 		.doit		= devlink_nl_rate_new_doit,
-		.post_doit	= devlink_nl_post_doit,
+		.post_doit	= devlink_nl_post_doit_parent_dev_optional,
 		.policy		= devlink_rate_new_nl_policy,
-		.maxattr	= DEVLINK_ATTR_RATE_TC_BWS,
+		.maxattr	= DEVLINK_ATTR_PARENT_DEV,
 		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
 	},
 	{
-- 
2.31.1

[PATCH net-next 08/14] devlink: Allow rate node parents from other devlinks

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

This commit makes use of the building blocks previously added to
implement cross-device rate nodes.

A new 'supported_cross_device_rate_nodes' bool is added to devlink_ops
which lets drivers advertise support for cross-device rate objects.
If enabled and if there is a common shared devlink instance, then:
- all rate objects will be stored in the top-most common nested instance
  and
- rate objects can have parents from other devices sharing the same
  common instance.

The parent devlink from info->user_ptr[1] is not locked, so none of its
mutable fields can be used. But parent setting only requires comparing
devlink pointer comparisons. Additionally, since the shared devlink is
locked, other rate operations cannot concurrently happen.

The rate lock/unlock functions are now exported, so that drivers
implementing this can protect against concurrent modifications on any
shared device structures.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../networking/devlink/devlink-port.rst       |  2 +
 include/net/devlink.h                         |  5 ++
 net/devlink/rate.c                            | 90 +++++++++++++++++--
 3 files changed, 89 insertions(+), 8 deletions(-)

diff --git a/Documentation/networking/devlink/devlink-port.rst b/Documentation/networking/devlink/devlink-port.rst
index 5e397798a402..976bc5ca0962 100644
--- a/Documentation/networking/devlink/devlink-port.rst
+++ b/Documentation/networking/devlink/devlink-port.rst
@@ -417,6 +417,8 @@ API allows to configure following rate object's parameters:
   Parent node name. Parent node rate limits are considered as additional limits
   to all node children limits. ``tx_max`` is an upper limit for children.
   ``tx_share`` is a total bandwidth distributed among children.
+  If the device supports cross-function scheduling, the parent can be from a
+  different function of the same underlying device.
 
 ``tc_bw``
   Allow users to set the bandwidth allocation per traffic class on rate
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 7e7789098f0e..1cbd37aee3e3 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1542,6 +1542,11 @@ struct devlink_ops {
 				    struct devlink_rate *parent,
 				    void *priv_child, void *priv_parent,
 				    struct netlink_ext_ack *extack);
+	/* Indicates if cross-device rate nodes are supported.
+	 * This also requires a shared common ancestor object all devices that
+	 * could share rate nodes are nested in.
+	 */
+	bool supported_cross_device_rate_nodes;
 	/**
 	 * selftests_check() - queries if selftest is supported
 	 * @devlink: devlink instance
diff --git a/net/devlink/rate.c b/net/devlink/rate.c
index ddbd0beec4b9..f0a2a746cf23 100644
--- a/net/devlink/rate.c
+++ b/net/devlink/rate.c
@@ -30,20 +30,56 @@ devlink_rate_leaf_get_from_info(struct devlink *devlink, struct genl_info *info)
 	return devlink_rate ?: ERR_PTR(-ENODEV);
 }
 
+/* Repeatedly locks the nested-in devlink instances while cross device rate
+ * nodes are supported. Returns the devlink instance where rates should be
+ * stored.
+ */
 struct devlink *devl_rate_lock(struct devlink *devlink)
 {
-	return devlink;
+	struct devlink *rate_devlink = devlink;
+
+	while (rate_devlink->ops &&
+	       rate_devlink->ops->supported_cross_device_rate_nodes) {
+		devlink = devlink_nested_in_get_lock(rate_devlink->rel);
+		if (!devlink)
+			break;
+		rate_devlink = devlink;
+	}
+	return rate_devlink;
 }
+EXPORT_SYMBOL_GPL(devl_rate_lock);
 
+/* Variant of the above for when the nested-in devlink instances are already
+ * locked.
+ */
 static struct devlink *
 devl_get_rate_node_instance_locked(struct devlink *devlink)
 {
-	return devlink;
+	struct devlink *rate_devlink = devlink;
+
+	while (rate_devlink->ops &&
+	       rate_devlink->ops->supported_cross_device_rate_nodes) {
+		devlink = devlink_nested_in_get_locked(rate_devlink->rel);
+		if (!devlink)
+			break;
+		rate_devlink = devlink;
+	}
+	return rate_devlink;
 }
 
+/* Repeatedly unlocks the nested-in devlink instances of 'devlink' while cross
+ * device nodes are supported.
+ */
 void devl_rate_unlock(struct devlink *devlink)
 {
+	if (!devlink || !devlink->ops ||
+	    !devlink->ops->supported_cross_device_rate_nodes)
+		return;
+
+	devl_rate_unlock(devlink_nested_in_get_locked(devlink->rel));
+	devlink_nested_in_put_unlock(devlink->rel);
 }
+EXPORT_SYMBOL_GPL(devl_rate_unlock);
 
 static struct devlink_rate *
 devlink_rate_node_get_by_name(struct devlink *devlink, const char *node_name)
@@ -120,6 +156,24 @@ static int devlink_rate_put_tc_bws(struct sk_buff *msg, u32 *tc_bw)
 	return -EMSGSIZE;
 }
 
+static int devlink_nl_rate_parent_fill(struct sk_buff *msg,
+				       struct devlink_rate *devlink_rate)
+{
+	struct devlink_rate *parent = devlink_rate->parent;
+	struct devlink *devlink = parent->devlink;
+
+	if (nla_put_string(msg, DEVLINK_ATTR_RATE_PARENT_NODE_NAME,
+			   parent->name))
+		return -EMSGSIZE;
+
+	if (devlink != devlink_rate->devlink &&
+	    devlink_nl_put_nested_handle(msg, devlink_net(devlink), devlink,
+					 DEVLINK_ATTR_PARENT_DEV))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
 static int devlink_nl_rate_fill(struct sk_buff *msg,
 				struct devlink_rate *devlink_rate,
 				enum devlink_command cmd, u32 portid, u32 seq,
@@ -164,10 +218,9 @@ static int devlink_nl_rate_fill(struct sk_buff *msg,
 			devlink_rate->tx_weight))
 		goto nla_put_failure;
 
-	if (devlink_rate->parent)
-		if (nla_put_string(msg, DEVLINK_ATTR_RATE_PARENT_NODE_NAME,
-				   devlink_rate->parent->name))
-			goto nla_put_failure;
+	if (devlink_rate->parent &&
+	    devlink_nl_rate_parent_fill(msg, devlink_rate))
+		goto nla_put_failure;
 
 	if (devlink_rate_put_tc_bws(msg, devlink_rate->tc_bw))
 		goto nla_put_failure;
@@ -322,13 +375,14 @@ devlink_nl_rate_parent_node_set(struct devlink_rate *devlink_rate,
 				struct genl_info *info,
 				struct nlattr *nla_parent)
 {
-	struct devlink *devlink = devlink_rate->devlink;
+	struct devlink *devlink = devlink_rate->devlink, *parent_devlink;
 	const char *parent_name = nla_data(nla_parent);
 	const struct devlink_ops *ops = devlink->ops;
 	size_t len = strlen(parent_name);
 	struct devlink_rate *parent;
 	int err = -EOPNOTSUPP;
 
+	parent_devlink = info->user_ptr[1] ? : devlink;
 	parent = devlink_rate->parent;
 
 	if (parent && !len) {
@@ -346,7 +400,13 @@ devlink_nl_rate_parent_node_set(struct devlink_rate *devlink_rate,
 		refcount_dec(&parent->refcnt);
 		devlink_rate->parent = NULL;
 	} else if (len) {
-		parent = devlink_rate_node_get_by_name(devlink, parent_name);
+		/* parent_devlink (when different than devlink) isn't locked,
+		 * but the rate node devlink instance is, so nobody from the
+		 * same group of devices sharing rates could change the used
+		 * fields or unregister the parent.
+		 */
+		parent = devlink_rate_node_get_by_name(parent_devlink,
+						       parent_name);
 		if (IS_ERR(parent))
 			return -ENODEV;
 
@@ -646,6 +706,13 @@ int devlink_nl_rate_set_doit(struct sk_buff *skb, struct genl_info *info)
 		goto unlock;
 	}
 
+	if (info->user_ptr[1] && info->user_ptr[1] != devlink &&
+	    !ops->supported_cross_device_rate_nodes) {
+		NL_SET_ERR_MSG(info->extack,
+			       "Cross-device rate parents aren't supported");
+		return -EOPNOTSUPP;
+	}
+
 	err = devlink_nl_rate_set(devlink_rate, ops, info);
 
 	if (!err)
@@ -671,6 +738,13 @@ int devlink_nl_rate_new_doit(struct sk_buff *skb, struct genl_info *info)
 	if (!devlink_rate_set_ops_supported(ops, info, DEVLINK_RATE_TYPE_NODE))
 		return -EOPNOTSUPP;
 
+	if (info->user_ptr[1] && info->user_ptr[1] != devlink &&
+	    !ops->supported_cross_device_rate_nodes) {
+		NL_SET_ERR_MSG(info->extack,
+			       "Cross-device rate parents aren't supported");
+		return -EOPNOTSUPP;
+	}
+
 	rate_devlink = devl_rate_lock(devlink);
 	rate_node = devlink_rate_node_get_from_attrs(devlink, info->attrs);
 	if (!IS_ERR(rate_node)) {
-- 
2.31.1

Re: [PATCH net-next 08/14] devlink: Allow rate node parents from other devlinks

[Jiri Pirko]

Thu, Nov 20, 2025 at 02:09:20PM +0100, tariqt@nvidia.com wrote:
>From: Cosmin Ratiu <cratiu@nvidia.com>
>
>This commit makes use of the building blocks previously added to
>implement cross-device rate nodes.
>
>A new 'supported_cross_device_rate_nodes' bool is added to devlink_ops
>which lets drivers advertise support for cross-device rate objects.
>If enabled and if there is a common shared devlink instance, then:
>- all rate objects will be stored in the top-most common nested instance
>  and
>- rate objects can have parents from other devices sharing the same
>  common instance.
>
>The parent devlink from info->user_ptr[1] is not locked, so none of its
>mutable fields can be used. But parent setting only requires comparing
>devlink pointer comparisons. Additionally, since the shared devlink is
>locked, other rate operations cannot concurrently happen.
>
>The rate lock/unlock functions are now exported, so that drivers
>implementing this can protect against concurrent modifications on any
>shared device structures.
>
>Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
>Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
>Signed-off-by: Tariq Toukan <tariqt@nvidia.com>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

[PATCH net-next 09/14] net/mlx5: Introduce shared devlink instance for PFs on same chip

[Tariq Toukan]

From: Jiri Pirko <jiri@nvidia.com>

Multiple PFs may reside on the same physical chip, running a single
firmware. Some of the resources and configurations may be shared among
these PFs. Currently, there is not good object to pin the configuration
knobs on.

Introduce a shared devlink, instantiated upon probe of the first PF,
removed during remove of the last PF. Back this shared devlink instance
by faux device, as there is no PCI device related to it.

Make the PF devlink instances nested in this shared devlink instance.

Example:

$ devlink dev
pci/0000:08:00.0:
  nested_devlink:
    auxiliary/mlx5_core.eth.0
faux/mlx5_core_83013c12b77faa1a30000c82a1045c91:
  nested_devlink:
    pci/0000:08:00.0
    pci/0000:08:00.1
auxiliary/mlx5_core.eth.0
pci/0000:08:00.1:
  nested_devlink:
    auxiliary/mlx5_core.eth.1
auxiliary/mlx5_core.eth.1

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../net/ethernet/mellanox/mlx5/core/Makefile  |   5 +-
 .../net/ethernet/mellanox/mlx5/core/main.c    |  18 ++
 .../ethernet/mellanox/mlx5/core/sh_devlink.c  | 166 ++++++++++++++++++
 .../ethernet/mellanox/mlx5/core/sh_devlink.h  |  13 ++
 include/linux/mlx5/driver.h                   |   5 +
 5 files changed, 205 insertions(+), 2 deletions(-)
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.h

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/Makefile b/drivers/net/ethernet/mellanox/mlx5/core/Makefile
index 8ffa286a18f5..d39fe9c4a87c 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/Makefile
+++ b/drivers/net/ethernet/mellanox/mlx5/core/Makefile
@@ -16,8 +16,9 @@ mlx5_core-y :=	main.o cmd.o debugfs.o fw.o eq.o uar.o pagealloc.o \
 		transobj.o vport.o sriov.o fs_cmd.o fs_core.o pci_irq.o \
 		fs_counters.o fs_ft_pool.o rl.o lag/debugfs.o lag/lag.o dev.o events.o wq.o lib/gid.o \
 		lib/devcom.o lib/pci_vsc.o lib/dm.o lib/fs_ttc.o diag/fs_tracepoint.o \
-		diag/fw_tracer.o diag/crdump.o devlink.o diag/rsc_dump.o diag/reporter_vnic.o \
-		fw_reset.o qos.o lib/tout.o lib/aso.o wc.o fs_pool.o lib/nv_param.o
+		diag/fw_tracer.o diag/crdump.o devlink.o sh_devlink.o diag/rsc_dump.o \
+		diag/reporter_vnic.o fw_reset.o qos.o lib/tout.o lib/aso.o wc.o fs_pool.o \
+		lib/nv_param.o
 
 #
 # Netdev basic
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c
index 024339ce41f1..a8a285917688 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
@@ -74,6 +74,7 @@
 #include "mlx5_irq.h"
 #include "hwmon.h"
 #include "lag/lag.h"
+#include "sh_devlink.h"
 
 MODULE_AUTHOR("Eli Cohen <eli@mellanox.com>");
 MODULE_DESCRIPTION("Mellanox 5th generation network adapters (ConnectX series) core driver");
@@ -1520,10 +1521,17 @@ int mlx5_init_one(struct mlx5_core_dev *dev)
 	int err;
 
 	devl_lock(devlink);
+	if (dev->shd) {
+		err = devl_nested_devlink_set(priv_to_devlink(dev->shd),
+					      devlink);
+		if (err)
+			goto unlock;
+	}
 	devl_register(devlink);
 	err = mlx5_init_one_devl_locked(dev);
 	if (err)
 		devl_unregister(devlink);
+unlock:
 	devl_unlock(devlink);
 	return err;
 }
@@ -2015,6 +2023,13 @@ static int probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto pci_init_err;
 	}
 
+	err = mlx5_shd_init(dev);
+	if (err) {
+		mlx5_core_err(dev, "mlx5_shd_init failed with error code %d\n",
+			      err);
+		goto shd_init_err;
+	}
+
 	err = mlx5_init_one(dev);
 	if (err) {
 		mlx5_core_err(dev, "mlx5_init_one failed with error code %d\n",
@@ -2026,6 +2041,8 @@ static int probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	return 0;
 
 err_init_one:
+	mlx5_shd_uninit(dev);
+shd_init_err:
 	mlx5_pci_close(dev);
 pci_init_err:
 	mlx5_mdev_uninit(dev);
@@ -2047,6 +2064,7 @@ static void remove_one(struct pci_dev *pdev)
 	mlx5_drain_health_wq(dev);
 	mlx5_sriov_disable(pdev, false);
 	mlx5_uninit_one(dev);
+	mlx5_shd_uninit(dev);
 	mlx5_pci_close(dev);
 	mlx5_mdev_uninit(dev);
 	mlx5_adev_idx_free(dev->priv.adev_idx);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c
new file mode 100644
index 000000000000..e39a5e20e102
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */
+
+#include <linux/device/faux.h>
+#include <linux/mlx5/driver.h>
+#include <linux/mlx5/vport.h>
+
+#include "sh_devlink.h"
+
+static LIST_HEAD(shd_list);
+static DEFINE_MUTEX(shd_mutex); /* Protects shd_list and shd->list */
+
+/* This structure represents a shared devlink instance,
+ * there is one created for PF group of the same chip.
+ */
+struct mlx5_shd {
+	/* Node in shd list */
+	struct list_head list;
+	/* Serial number of the chip */
+	const char *sn;
+	/* List of per-PF dev instances */
+	struct list_head dev_list;
+	/* Related faux device */
+	struct faux_device *faux_dev;
+};
+
+static const struct devlink_ops mlx5_shd_ops = {
+};
+
+static int mlx5_shd_faux_probe(struct faux_device *faux_dev)
+{
+	struct devlink *devlink;
+	struct mlx5_shd *shd;
+
+	devlink = devlink_alloc(&mlx5_shd_ops, sizeof(struct mlx5_shd),
+				&faux_dev->dev);
+	if (!devlink)
+		return -ENOMEM;
+	shd = devlink_priv(devlink);
+	faux_device_set_drvdata(faux_dev, shd);
+
+	devl_lock(devlink);
+	devl_register(devlink);
+	devl_unlock(devlink);
+	return 0;
+}
+
+static void mlx5_shd_faux_remove(struct faux_device *faux_dev)
+{
+	struct mlx5_shd *shd = faux_device_get_drvdata(faux_dev);
+	struct devlink *devlink = priv_to_devlink(shd);
+
+	devl_lock(devlink);
+	devl_unregister(devlink);
+	devl_unlock(devlink);
+	devlink_free(devlink);
+}
+
+static const struct faux_device_ops mlx5_shd_faux_ops = {
+	.probe = mlx5_shd_faux_probe,
+	.remove = mlx5_shd_faux_remove,
+};
+
+static struct mlx5_shd *mlx5_shd_create(const char *sn)
+{
+	struct faux_device *faux_dev;
+	struct mlx5_shd *shd;
+
+	faux_dev = faux_device_create(sn, NULL, &mlx5_shd_faux_ops);
+	if (!faux_dev)
+		return NULL;
+	shd = faux_device_get_drvdata(faux_dev);
+	if (!shd)
+		return NULL;
+	list_add_tail(&shd->list, &shd_list);
+	shd->sn = sn;
+	INIT_LIST_HEAD(&shd->dev_list);
+	shd->faux_dev = faux_dev;
+	return shd;
+}
+
+static void mlx5_shd_destroy(struct mlx5_shd *shd)
+{
+	list_del(&shd->list);
+	kfree(shd->sn);
+	faux_device_destroy(shd->faux_dev);
+}
+
+int mlx5_shd_init(struct mlx5_core_dev *dev)
+{
+	u8 *vpd_data __free(kfree) = NULL;
+	struct pci_dev *pdev = dev->pdev;
+	unsigned int vpd_size, kw_len;
+	struct mlx5_shd *shd;
+	const char *sn;
+	char *end;
+	int start;
+	int err;
+
+	if (!mlx5_core_is_pf(dev))
+		return 0;
+
+	vpd_data = pci_vpd_alloc(pdev, &vpd_size);
+	if (IS_ERR(vpd_data)) {
+		err = PTR_ERR(vpd_data);
+		return err == -ENODEV ? 0 : err;
+	}
+	start = pci_vpd_find_ro_info_keyword(vpd_data, vpd_size, "V3", &kw_len);
+	if (start < 0) {
+		/* Fall-back to SN for older devices. */
+		start = pci_vpd_find_ro_info_keyword(vpd_data, vpd_size,
+						     PCI_VPD_RO_KEYWORD_SERIALNO, &kw_len);
+		if (start < 0)
+			return -ENOENT;
+	}
+	sn = kstrndup(vpd_data + start, kw_len, GFP_KERNEL);
+	if (!sn)
+		return -ENOMEM;
+	/* Firmware may return spaces at the end of the string, strip it. */
+	end = strchrnul(sn, ' ');
+	*end = '\0';
+
+	guard(mutex)(&shd_mutex);
+	list_for_each_entry(shd, &shd_list, list) {
+		if (!strcmp(shd->sn, sn)) {
+			kfree(sn);
+			goto found;
+		}
+	}
+	shd = mlx5_shd_create(sn);
+	if (!shd) {
+		kfree(sn);
+		return -ENOMEM;
+	}
+found:
+	list_add_tail(&dev->shd_list, &shd->dev_list);
+	dev->shd = shd;
+	return 0;
+}
+
+void mlx5_shd_uninit(struct mlx5_core_dev *dev)
+{
+	struct mlx5_shd *shd = dev->shd;
+
+	if (!dev->shd)
+		return;
+
+	guard(mutex)(&shd_mutex);
+	list_del(&dev->shd_list);
+	if (list_empty(&shd->dev_list))
+		mlx5_shd_destroy(shd);
+}
+
+void mlx5_shd_lock(struct mlx5_core_dev *dev)
+{
+	if (!dev->shd)
+		return;
+	devl_lock(priv_to_devlink(dev->shd));
+}
+
+void mlx5_shd_unlock(struct mlx5_core_dev *dev)
+{
+	if (!dev->shd)
+		return;
+	devl_unlock(priv_to_devlink(dev->shd));
+}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.h b/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.h
new file mode 100644
index 000000000000..54ce0389cfea
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) 2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */
+
+#ifndef __MLX5_SH_DEVLINK_H__
+#define __MLX5_SH_DEVLINK_H__
+
+int mlx5_shd_init(struct mlx5_core_dev *dev);
+void mlx5_shd_uninit(struct mlx5_core_dev *dev);
+void mlx5_shd_lock(struct mlx5_core_dev *dev);
+void mlx5_shd_unlock(struct mlx5_core_dev *dev);
+void mlx5_shd_nested_set(struct mlx5_core_dev *dev);
+
+#endif /* __MLX5_SH_DEVLINK_H__ */
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index 1c54aa6f74fb..29fd4dff1cd1 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -735,6 +735,8 @@ enum mlx5_wc_state {
 	MLX5_WC_STATE_SUPPORTED,
 };
 
+struct mlx5_shd;
+
 struct mlx5_core_dev {
 	struct device *device;
 	enum mlx5_coredev_type coredev_type;
@@ -798,6 +800,9 @@ struct mlx5_core_dev {
 	enum mlx5_wc_state wc_state;
 	/* sync write combining state */
 	struct mutex wc_state_lock;
+	/* node in shared devlink list */
+	struct list_head shd_list;
+	struct mlx5_shd *shd;
 };
 
 struct mlx5_db {
-- 
2.31.1

[PATCH net-next 10/14] net/mlx5: Expose a function to clear a vport's parent

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

Currently, clearing a vport's parent happens with a call that looks like
this:
	mlx5_esw_qos_vport_update_parent(vport, NULL, NULL);

Change that to something nicer that looks like this:
	mlx5_esw_qos_vport_clear_parent(vport);

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../ethernet/mellanox/mlx5/core/esw/devlink_port.c    |  2 +-
 drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c     | 11 +++++++++--
 drivers/net/ethernet/mellanox/mlx5/core/eswitch.h     |  3 +--
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/devlink_port.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/devlink_port.c
index 89a58dee50b3..31704ea9cdb4 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/devlink_port.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/devlink_port.c
@@ -202,7 +202,7 @@ void mlx5_esw_offloads_devlink_port_unregister(struct mlx5_vport *vport)
 		return;
 	dl_port = vport->dl_port;
 
-	mlx5_esw_qos_vport_update_parent(vport, NULL, NULL);
+	mlx5_esw_qos_vport_clear_parent(vport);
 	devl_rate_leaf_destroy(&dl_port->dl_port);
 
 	devl_port_unregister(&dl_port->dl_port);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
index 4278bcb04c72..8c3a026b8db4 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
@@ -1896,8 +1896,10 @@ int mlx5_esw_devlink_rate_node_del(struct devlink_rate *rate_node, void *priv,
 	return 0;
 }
 
-int mlx5_esw_qos_vport_update_parent(struct mlx5_vport *vport, struct mlx5_esw_sched_node *parent,
-				     struct netlink_ext_ack *extack)
+static int
+mlx5_esw_qos_vport_update_parent(struct mlx5_vport *vport,
+				 struct mlx5_esw_sched_node *parent,
+				 struct netlink_ext_ack *extack)
 {
 	struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
 	int err = 0;
@@ -1922,6 +1924,11 @@ int mlx5_esw_qos_vport_update_parent(struct mlx5_vport *vport, struct mlx5_esw_s
 	return err;
 }
 
+void mlx5_esw_qos_vport_clear_parent(struct mlx5_vport *vport)
+{
+	mlx5_esw_qos_vport_update_parent(vport, NULL, NULL);
+}
+
 int mlx5_esw_devlink_rate_leaf_parent_set(struct devlink_rate *devlink_rate,
 					  struct devlink_rate *parent,
 					  void *priv, void *parent_priv,
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
index ad1073f7b79f..20cf9dd542a1 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
@@ -452,8 +452,7 @@ int mlx5_eswitch_set_vport_trust(struct mlx5_eswitch *esw,
 				 u16 vport_num, bool setting);
 int mlx5_eswitch_set_vport_rate(struct mlx5_eswitch *esw, u16 vport,
 				u32 max_rate, u32 min_rate);
-int mlx5_esw_qos_vport_update_parent(struct mlx5_vport *vport, struct mlx5_esw_sched_node *node,
-				     struct netlink_ext_ack *extack);
+void mlx5_esw_qos_vport_clear_parent(struct mlx5_vport *vport);
 int mlx5_eswitch_set_vepa(struct mlx5_eswitch *esw, u8 setting);
 int mlx5_eswitch_get_vepa(struct mlx5_eswitch *esw, u8 *setting);
 int mlx5_eswitch_get_vport_config(struct mlx5_eswitch *esw,
-- 
2.31.1

[PATCH net-next 11/14] net/mlx5: Store QoS sched nodes in the sh_devlink

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

In order to support cross-esw scheduling, the nodes for all devices need
to be accessible from the same place so that normalization can work.
Store them in the shared devlink instance and provide an accessor for
them.

Protecting against concurrent QoS modifications is now done with
the shd lock. All calls originating from devlink rate already have the
shd lock held so only the additional entry points into QoS need to
acquire it.

As part of this change, the E-Switch qos domain concept was removed.
E-Switch QoS domains were added with the intention of eventually
implementing shared qos domains to support cross-esw scheduling in the
previous approach ([1]), but they are no longer necessary in the new
approach.

[1] https://lore.kernel.org/netdev/20250213180134.323929-1-tariqt@nvidia.com/

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../net/ethernet/mellanox/mlx5/core/esw/qos.c | 201 +++++-------------
 .../net/ethernet/mellanox/mlx5/core/esw/qos.h |   3 -
 .../net/ethernet/mellanox/mlx5/core/eswitch.c |   9 +-
 .../net/ethernet/mellanox/mlx5/core/eswitch.h |  11 +-
 .../ethernet/mellanox/mlx5/core/sh_devlink.c  |  17 ++
 .../ethernet/mellanox/mlx5/core/sh_devlink.h  |   3 +
 6 files changed, 76 insertions(+), 168 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
index 8c3a026b8db4..f86d7c50db42 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
@@ -5,60 +5,16 @@
 #include "lib/mlx5.h"
 #include "esw/qos.h"
 #include "en/port.h"
+#include "sh_devlink.h"
 #define CREATE_TRACE_POINTS
 #include "diag/qos_tracepoint.h"
 
 /* Minimum supported BW share value by the HW is 1 Mbit/sec */
 #define MLX5_MIN_BW_SHARE 1
 
-/* Holds rate nodes associated with an E-Switch. */
-struct mlx5_qos_domain {
-	/* Serializes access to all qos changes in the qos domain. */
-	struct mutex lock;
-	/* List of all mlx5_esw_sched_nodes. */
-	struct list_head nodes;
-};
-
-static void esw_qos_lock(struct mlx5_eswitch *esw)
-{
-	mutex_lock(&esw->qos.domain->lock);
-}
-
-static void esw_qos_unlock(struct mlx5_eswitch *esw)
-{
-	mutex_unlock(&esw->qos.domain->lock);
-}
-
 static void esw_assert_qos_lock_held(struct mlx5_eswitch *esw)
 {
-	lockdep_assert_held(&esw->qos.domain->lock);
-}
-
-static struct mlx5_qos_domain *esw_qos_domain_alloc(void)
-{
-	struct mlx5_qos_domain *qos_domain;
-
-	qos_domain = kzalloc(sizeof(*qos_domain), GFP_KERNEL);
-	if (!qos_domain)
-		return NULL;
-
-	mutex_init(&qos_domain->lock);
-	INIT_LIST_HEAD(&qos_domain->nodes);
-
-	return qos_domain;
-}
-
-static int esw_qos_domain_init(struct mlx5_eswitch *esw)
-{
-	esw->qos.domain = esw_qos_domain_alloc();
-
-	return esw->qos.domain ? 0 : -ENOMEM;
-}
-
-static void esw_qos_domain_release(struct mlx5_eswitch *esw)
-{
-	kfree(esw->qos.domain);
-	esw->qos.domain = NULL;
+	mlx5_shd_assert_locked(esw->dev);
 }
 
 enum sched_node_type {
@@ -111,7 +67,8 @@ static void esw_qos_node_attach_to_parent(struct mlx5_esw_sched_node *node)
 	if (!node->parent) {
 		/* Root children are assigned a depth level of 2. */
 		node->level = 2;
-		list_add_tail(&node->entry, &node->esw->qos.domain->nodes);
+		list_add_tail(&node->entry,
+			      mlx5_shd_get_qos_nodes(node->esw->dev));
 	} else {
 		node->level = node->parent->level + 1;
 		list_add_tail(&node->entry, &node->parent->children);
@@ -324,14 +281,15 @@ static int esw_qos_create_rate_limit_element(struct mlx5_esw_sched_node *node,
 static u32 esw_qos_calculate_min_rate_divider(struct mlx5_eswitch *esw,
 					      struct mlx5_esw_sched_node *parent)
 {
-	struct list_head *nodes = parent ? &parent->children : &esw->qos.domain->nodes;
 	u32 fw_max_bw_share = MLX5_CAP_QOS(esw->dev, max_tsar_bw_share);
 	struct mlx5_esw_sched_node *node;
+	struct list_head *nodes;
 	u32 max_guarantee = 0;
 
 	/* Find max min_rate across all nodes.
 	 * This will correspond to fw_max_bw_share in the final bw_share calculation.
 	 */
+	nodes = parent ? &parent->children : mlx5_shd_get_qos_nodes(esw->dev);
 	list_for_each_entry(node, nodes, entry) {
 		if (node->esw == esw && node->ix != esw->qos.root_tsar_ix &&
 		    node->min_rate > max_guarantee)
@@ -372,10 +330,11 @@ static void esw_qos_normalize_min_rate(struct mlx5_eswitch *esw,
 				       struct mlx5_esw_sched_node *parent,
 				       struct netlink_ext_ack *extack)
 {
-	struct list_head *nodes = parent ? &parent->children : &esw->qos.domain->nodes;
 	u32 divider = esw_qos_calculate_min_rate_divider(esw, parent);
 	struct mlx5_esw_sched_node *node;
+	struct list_head *nodes;
 
+	nodes = parent ? &parent->children : mlx5_shd_get_qos_nodes(esw->dev);
 	list_for_each_entry(node, nodes, entry) {
 		if (node->esw != esw || node->ix == esw->qos.root_tsar_ix)
 			continue;
@@ -715,7 +674,7 @@ __esw_qos_create_vports_sched_node(struct mlx5_eswitch *esw, struct mlx5_esw_sch
 		goto err_alloc_node;
 	}
 
-	list_add_tail(&node->entry, &esw->qos.domain->nodes);
+	list_add_tail(&node->entry, mlx5_shd_get_qos_nodes(esw->dev));
 	esw_qos_normalize_min_rate(esw, NULL, extack);
 	trace_mlx5_esw_node_qos_create(esw->dev, node, node->ix);
 
@@ -1108,7 +1067,8 @@ static int mlx5_esw_qos_vport_enable(struct mlx5_vport *vport, enum sched_node_t
 		return -ENOMEM;
 	}
 	if (!parent)
-		list_add_tail(&sched_node->entry, &esw->qos.domain->nodes);
+		list_add_tail(&sched_node->entry,
+			      mlx5_shd_get_qos_nodes(esw->dev));
 
 	sched_node->max_rate = max_rate;
 	sched_node->min_rate = min_rate;
@@ -1143,7 +1103,7 @@ void mlx5_esw_qos_vport_disable(struct mlx5_vport *vport)
 	struct mlx5_esw_sched_node *parent;
 
 	lockdep_assert_held(&esw->state_lock);
-	esw_qos_lock(esw);
+	mlx5_shd_lock(esw->dev);
 	if (!vport->qos.sched_node)
 		goto unlock;
 
@@ -1152,7 +1112,7 @@ void mlx5_esw_qos_vport_disable(struct mlx5_vport *vport)
 
 	mlx5_esw_qos_vport_disable_locked(vport);
 unlock:
-	esw_qos_unlock(esw);
+	mlx5_shd_unlock(esw->dev);
 }
 
 static int mlx5_esw_qos_set_vport_max_rate(struct mlx5_vport *vport, u32 max_rate,
@@ -1191,26 +1151,25 @@ int mlx5_esw_qos_set_vport_rate(struct mlx5_vport *vport, u32 max_rate, u32 min_
 	struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
 	int err;
 
-	esw_qos_lock(esw);
+	mlx5_shd_lock(esw->dev);
 	err = mlx5_esw_qos_set_vport_min_rate(vport, min_rate, NULL);
 	if (!err)
 		err = mlx5_esw_qos_set_vport_max_rate(vport, max_rate, NULL);
-	esw_qos_unlock(esw);
+	mlx5_shd_unlock(esw->dev);
 	return err;
 }
 
 bool mlx5_esw_qos_get_vport_rate(struct mlx5_vport *vport, u32 *max_rate, u32 *min_rate)
 {
-	struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
 	bool enabled;
 
-	esw_qos_lock(esw);
+	mlx5_shd_lock(vport->dev);
 	enabled = !!vport->qos.sched_node;
 	if (enabled) {
 		*max_rate = vport->qos.sched_node->max_rate;
 		*min_rate = vport->qos.sched_node->min_rate;
 	}
-	esw_qos_unlock(esw);
+	mlx5_shd_unlock(vport->dev);
 	return enabled;
 }
 
@@ -1576,9 +1535,9 @@ int mlx5_esw_qos_modify_vport_rate(struct mlx5_eswitch *esw, u16 vport_num, u32
 			return err;
 	}
 
-	esw_qos_lock(esw);
+	mlx5_shd_lock(esw->dev);
 	err = mlx5_esw_qos_set_vport_max_rate(vport, rate_mbps, NULL);
-	esw_qos_unlock(esw);
+	mlx5_shd_unlock(esw->dev);
 
 	return err;
 }
@@ -1667,44 +1626,24 @@ static void esw_vport_qos_prune_empty(struct mlx5_vport *vport)
 	mlx5_esw_qos_vport_disable_locked(vport);
 }
 
-int mlx5_esw_qos_init(struct mlx5_eswitch *esw)
-{
-	if (esw->qos.domain)
-		return 0;  /* Nothing to change. */
-
-	return esw_qos_domain_init(esw);
-}
-
-void mlx5_esw_qos_cleanup(struct mlx5_eswitch *esw)
-{
-	if (esw->qos.domain)
-		esw_qos_domain_release(esw);
-}
-
 /* Eswitch devlink rate API */
 
 int mlx5_esw_devlink_rate_leaf_tx_share_set(struct devlink_rate *rate_leaf, void *priv,
 					    u64 tx_share, struct netlink_ext_ack *extack)
 {
 	struct mlx5_vport *vport = priv;
-	struct mlx5_eswitch *esw;
 	int err;
 
-	esw = vport->dev->priv.eswitch;
-	if (!mlx5_esw_allowed(esw))
+	if (!mlx5_esw_allowed(vport->dev->priv.eswitch))
 		return -EPERM;
 
 	err = esw_qos_devlink_rate_to_mbps(vport->dev, "tx_share", &tx_share, extack);
 	if (err)
 		return err;
 
-	esw_qos_lock(esw);
 	err = mlx5_esw_qos_set_vport_min_rate(vport, tx_share, extack);
-	if (err)
-		goto out;
-	esw_vport_qos_prune_empty(vport);
-out:
-	esw_qos_unlock(esw);
+	if (!err)
+		esw_vport_qos_prune_empty(vport);
 	return err;
 }
 
@@ -1712,24 +1651,18 @@ int mlx5_esw_devlink_rate_leaf_tx_max_set(struct devlink_rate *rate_leaf, void *
 					  u64 tx_max, struct netlink_ext_ack *extack)
 {
 	struct mlx5_vport *vport = priv;
-	struct mlx5_eswitch *esw;
 	int err;
 
-	esw = vport->dev->priv.eswitch;
-	if (!mlx5_esw_allowed(esw))
+	if (!mlx5_esw_allowed(vport->dev->priv.eswitch))
 		return -EPERM;
 
 	err = esw_qos_devlink_rate_to_mbps(vport->dev, "tx_max", &tx_max, extack);
 	if (err)
 		return err;
 
-	esw_qos_lock(esw);
 	err = mlx5_esw_qos_set_vport_max_rate(vport, tx_max, extack);
-	if (err)
-		goto out;
-	esw_vport_qos_prune_empty(vport);
-out:
-	esw_qos_unlock(esw);
+	if (!err)
+		esw_vport_qos_prune_empty(vport);
 	return err;
 }
 
@@ -1740,34 +1673,30 @@ int mlx5_esw_devlink_rate_leaf_tc_bw_set(struct devlink_rate *rate_leaf,
 {
 	struct mlx5_esw_sched_node *vport_node;
 	struct mlx5_vport *vport = priv;
-	struct mlx5_eswitch *esw;
 	bool disable;
 	int err = 0;
 
-	esw = vport->dev->priv.eswitch;
-	if (!mlx5_esw_allowed(esw))
+	if (!mlx5_esw_allowed(vport->dev->priv.eswitch))
 		return -EPERM;
 
 	disable = esw_qos_tc_bw_disabled(tc_bw);
-	esw_qos_lock(esw);
 
 	if (!esw_qos_vport_validate_unsupported_tc_bw(vport, tc_bw)) {
 		NL_SET_ERR_MSG_MOD(extack,
 				   "E-Switch traffic classes number is not supported");
-		err = -EOPNOTSUPP;
-		goto unlock;
+		return -EOPNOTSUPP;
 	}
 
 	vport_node = vport->qos.sched_node;
 	if (disable && !vport_node)
-		goto unlock;
+		return 0;
 
 	if (disable) {
 		if (vport_node->type == SCHED_NODE_TYPE_TC_ARBITER_TSAR)
 			err = esw_qos_vport_update(vport, SCHED_NODE_TYPE_VPORT,
 						   vport_node->parent, extack);
 		esw_vport_qos_prune_empty(vport);
-		goto unlock;
+		return err;
 	}
 
 	if (!vport_node) {
@@ -1782,8 +1711,6 @@ int mlx5_esw_devlink_rate_leaf_tc_bw_set(struct devlink_rate *rate_leaf,
 	}
 	if (!err)
 		esw_qos_set_tc_arbiter_bw_shares(vport_node, tc_bw, extack);
-unlock:
-	esw_qos_unlock(esw);
 	return err;
 }
 
@@ -1793,28 +1720,22 @@ int mlx5_esw_devlink_rate_node_tc_bw_set(struct devlink_rate *rate_node,
 					 struct netlink_ext_ack *extack)
 {
 	struct mlx5_esw_sched_node *node = priv;
-	struct mlx5_eswitch *esw = node->esw;
 	bool disable;
 	int err;
 
-	if (!esw_qos_validate_unsupported_tc_bw(esw, tc_bw)) {
+	if (!esw_qos_validate_unsupported_tc_bw(node->esw, tc_bw)) {
 		NL_SET_ERR_MSG_MOD(extack,
 				   "E-Switch traffic classes number is not supported");
 		return -EOPNOTSUPP;
 	}
 
 	disable = esw_qos_tc_bw_disabled(tc_bw);
-	esw_qos_lock(esw);
-	if (disable) {
-		err = esw_qos_node_disable_tc_arbitration(node, extack);
-		goto unlock;
-	}
+	if (disable)
+		return esw_qos_node_disable_tc_arbitration(node, extack);
 
 	err = esw_qos_node_enable_tc_arbitration(node, extack);
 	if (!err)
 		esw_qos_set_tc_arbiter_bw_shares(node, tc_bw, extack);
-unlock:
-	esw_qos_unlock(esw);
 	return err;
 }
 
@@ -1822,17 +1743,14 @@ int mlx5_esw_devlink_rate_node_tx_share_set(struct devlink_rate *rate_node, void
 					    u64 tx_share, struct netlink_ext_ack *extack)
 {
 	struct mlx5_esw_sched_node *node = priv;
-	struct mlx5_eswitch *esw = node->esw;
 	int err;
 
-	err = esw_qos_devlink_rate_to_mbps(esw->dev, "tx_share", &tx_share, extack);
+	err = esw_qos_devlink_rate_to_mbps(node->esw->dev, "tx_share",
+					   &tx_share, extack);
 	if (err)
 		return err;
 
-	esw_qos_lock(esw);
-	err = esw_qos_set_node_min_rate(node, tx_share, extack);
-	esw_qos_unlock(esw);
-	return err;
+	return esw_qos_set_node_min_rate(node, tx_share, extack);
 }
 
 int mlx5_esw_devlink_rate_node_tx_max_set(struct devlink_rate *rate_node, void *priv,
@@ -1846,10 +1764,7 @@ int mlx5_esw_devlink_rate_node_tx_max_set(struct devlink_rate *rate_node, void *
 	if (err)
 		return err;
 
-	esw_qos_lock(esw);
-	err = esw_qos_sched_elem_config(node, tx_max, node->bw_share, extack);
-	esw_qos_unlock(esw);
-	return err;
+	return esw_qos_sched_elem_config(node, tx_max, node->bw_share, extack);
 }
 
 int mlx5_esw_devlink_rate_node_new(struct devlink_rate *rate_node, void **priv,
@@ -1857,30 +1772,23 @@ int mlx5_esw_devlink_rate_node_new(struct devlink_rate *rate_node, void **priv,
 {
 	struct mlx5_esw_sched_node *node;
 	struct mlx5_eswitch *esw;
-	int err = 0;
 
 	esw = mlx5_devlink_eswitch_get(rate_node->devlink);
 	if (IS_ERR(esw))
 		return PTR_ERR(esw);
 
-	esw_qos_lock(esw);
 	if (esw->mode != MLX5_ESWITCH_OFFLOADS) {
 		NL_SET_ERR_MSG_MOD(extack,
 				   "Rate node creation supported only in switchdev mode");
-		err = -EOPNOTSUPP;
-		goto unlock;
+		return -EOPNOTSUPP;
 	}
 
 	node = esw_qos_create_vports_sched_node(esw, extack);
-	if (IS_ERR(node)) {
-		err = PTR_ERR(node);
-		goto unlock;
-	}
+	if (IS_ERR(node))
+		return PTR_ERR(node);
 
 	*priv = node;
-unlock:
-	esw_qos_unlock(esw);
-	return err;
+	return 0;
 }
 
 int mlx5_esw_devlink_rate_node_del(struct devlink_rate *rate_node, void *priv,
@@ -1889,10 +1797,9 @@ int mlx5_esw_devlink_rate_node_del(struct devlink_rate *rate_node, void *priv,
 	struct mlx5_esw_sched_node *node = priv;
 	struct mlx5_eswitch *esw = node->esw;
 
-	esw_qos_lock(esw);
 	__esw_qos_destroy_node(node, extack);
 	esw_qos_put(esw);
-	esw_qos_unlock(esw);
+
 	return 0;
 }
 
@@ -1909,7 +1816,6 @@ mlx5_esw_qos_vport_update_parent(struct mlx5_vport *vport,
 		return -EOPNOTSUPP;
 	}
 
-	esw_qos_lock(esw);
 	if (!vport->qos.sched_node && parent) {
 		enum sched_node_type type;
 
@@ -1920,13 +1826,15 @@ mlx5_esw_qos_vport_update_parent(struct mlx5_vport *vport,
 	} else if (vport->qos.sched_node) {
 		err = esw_qos_vport_update_parent(vport, parent, extack);
 	}
-	esw_qos_unlock(esw);
+
 	return err;
 }
 
 void mlx5_esw_qos_vport_clear_parent(struct mlx5_vport *vport)
 {
+	mlx5_shd_lock(vport->dev);
 	mlx5_esw_qos_vport_update_parent(vport, NULL, NULL);
+	mlx5_shd_unlock(vport->dev);
 }
 
 int mlx5_esw_devlink_rate_leaf_parent_set(struct devlink_rate *devlink_rate,
@@ -1939,13 +1847,8 @@ int mlx5_esw_devlink_rate_leaf_parent_set(struct devlink_rate *devlink_rate,
 	int err;
 
 	err = mlx5_esw_qos_vport_update_parent(vport, node, extack);
-	if (!err) {
-		struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
-
-		esw_qos_lock(esw);
+	if (!err)
 		esw_vport_qos_prune_empty(vport);
-		esw_qos_unlock(esw);
-	}
 
 	return err;
 }
@@ -2071,14 +1974,12 @@ static int mlx5_esw_qos_node_update_parent(struct mlx5_esw_sched_node *node,
 					   struct netlink_ext_ack *extack)
 {
 	struct mlx5_esw_sched_node *curr_parent;
-	struct mlx5_eswitch *esw = node->esw;
 	int err;
 
 	err = mlx5_esw_qos_node_validate_set_parent(node, parent, extack);
 	if (err)
 		return err;
 
-	esw_qos_lock(esw);
 	curr_parent = node->parent;
 	if (node->type == SCHED_NODE_TYPE_TC_ARBITER_TSAR) {
 		err = esw_qos_tc_arbiter_node_update_parent(node, parent,
@@ -2088,15 +1989,11 @@ static int mlx5_esw_qos_node_update_parent(struct mlx5_esw_sched_node *node,
 	}
 
 	if (err)
-		goto out;
-
-	esw_qos_normalize_min_rate(esw, curr_parent, extack);
-	esw_qos_normalize_min_rate(esw, parent, extack);
-
-out:
-	esw_qos_unlock(esw);
+		return err;
 
-	return err;
+	esw_qos_normalize_min_rate(node->esw, curr_parent, extack);
+	esw_qos_normalize_min_rate(node->esw, parent, extack);
+	return 0;
 }
 
 int mlx5_esw_devlink_rate_node_parent_set(struct devlink_rate *devlink_rate,
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.h b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.h
index 0a50982b0e27..f275e850d2c9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.h
@@ -6,9 +6,6 @@
 
 #ifdef CONFIG_MLX5_ESWITCH
 
-int mlx5_esw_qos_init(struct mlx5_eswitch *esw);
-void mlx5_esw_qos_cleanup(struct mlx5_eswitch *esw);
-
 int mlx5_esw_qos_set_vport_rate(struct mlx5_vport *evport, u32 max_rate, u32 min_rate);
 bool mlx5_esw_qos_get_vport_rate(struct mlx5_vport *vport, u32 *max_rate, u32 *min_rate);
 void mlx5_esw_qos_vport_disable(struct mlx5_vport *vport);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
index 3adf2b1cd26a..00658b44d429 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
@@ -49,6 +49,7 @@
 #include "ecpf.h"
 #include "en/mod_hdr.h"
 #include "en_accel/ipsec.h"
+#include "sh_devlink.h"
 
 enum {
 	MLX5_ACTION_NONE = 0,
@@ -1618,10 +1619,6 @@ int mlx5_eswitch_enable_locked(struct mlx5_eswitch *esw, int num_vfs)
 	MLX5_NB_INIT(&esw->nb, eswitch_vport_event, NIC_VPORT_CHANGE);
 	mlx5_eq_notifier_register(esw->dev, &esw->nb);
 
-	err = mlx5_esw_qos_init(esw);
-	if (err)
-		goto err_esw_init;
-
 	if (esw->mode == MLX5_ESWITCH_LEGACY) {
 		err = esw_legacy_enable(esw);
 	} else {
@@ -2027,9 +2024,6 @@ int mlx5_eswitch_init(struct mlx5_core_dev *dev)
 		goto reps_err;
 
 	esw->mode = MLX5_ESWITCH_LEGACY;
-	err = mlx5_esw_qos_init(esw);
-	if (err)
-		goto reps_err;
 
 	mutex_init(&esw->offloads.encap_tbl_lock);
 	hash_init(esw->offloads.encap_tbl);
@@ -2079,7 +2073,6 @@ void mlx5_eswitch_cleanup(struct mlx5_eswitch *esw)
 
 	esw_info(esw->dev, "cleanup\n");
 
-	mlx5_esw_qos_cleanup(esw);
 	destroy_workqueue(esw->work_queue);
 	WARN_ON(refcount_read(&esw->qos.refcnt));
 	mutex_destroy(&esw->state_lock);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
index 20cf9dd542a1..d145591b3434 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
@@ -224,8 +224,9 @@ struct mlx5_vport {
 
 	struct mlx5_vport_info  info;
 
-	/* Protected with the E-Switch qos domain lock. The Vport QoS can
-	 * either be disabled (sched_node is NULL) or in one of three states:
+	/* Protected by mlx5_shd_lock().
+	 * The Vport QoS can either be disabled (sched_node is NULL) or in one
+	 * of three states:
 	 * 1. Regular QoS (sched_node is a vport node).
 	 * 2. TC QoS enabled on the vport (sched_node is a TC arbiter).
 	 * 3. TC QoS enabled on the vport's parent node
@@ -356,7 +357,6 @@ enum {
 };
 
 struct dentry;
-struct mlx5_qos_domain;
 
 struct mlx5_eswitch {
 	struct mlx5_core_dev    *dev;
@@ -383,12 +383,13 @@ struct mlx5_eswitch {
 	struct rw_semaphore mode_lock;
 	atomic64_t user_count;
 
-	/* Protected with the E-Switch qos domain lock. */
+	/* The QoS tree is stored in mlx5_shd.
+	 * QoS changes are serialized with mlx5_shd_lock().
+	 */
 	struct {
 		/* Initially 0, meaning no QoS users and QoS is disabled. */
 		refcount_t refcnt;
 		u32 root_tsar_ix;
-		struct mlx5_qos_domain *domain;
 	} qos;
 
 	struct mlx5_esw_bridge_offloads *br_offloads;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c
index e39a5e20e102..ef073cc53f8e 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.c
@@ -22,6 +22,8 @@ struct mlx5_shd {
 	struct list_head dev_list;
 	/* Related faux device */
 	struct faux_device *faux_dev;
+	/* List of esw qos nodes. */
+	struct list_head qos_nodes;
 };
 
 static const struct devlink_ops mlx5_shd_ops = {
@@ -76,6 +78,7 @@ static struct mlx5_shd *mlx5_shd_create(const char *sn)
 	shd->sn = sn;
 	INIT_LIST_HEAD(&shd->dev_list);
 	shd->faux_dev = faux_dev;
+	INIT_LIST_HEAD(&shd->qos_nodes);
 	return shd;
 }
 
@@ -164,3 +167,17 @@ void mlx5_shd_unlock(struct mlx5_core_dev *dev)
 		return;
 	devl_unlock(priv_to_devlink(dev->shd));
 }
+
+void mlx5_shd_assert_locked(struct mlx5_core_dev *dev)
+{
+	if (dev->shd)
+		devl_assert_locked(priv_to_devlink(dev->shd));
+}
+
+struct list_head *mlx5_shd_get_qos_nodes(struct mlx5_core_dev *dev)
+{
+	if (!dev->shd)
+		return NULL;
+	mlx5_shd_assert_locked(dev);
+	return &dev->shd->qos_nodes;
+}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.h b/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.h
index 54ce0389cfea..56ead7e11756 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sh_devlink.h
@@ -8,6 +8,9 @@ int mlx5_shd_init(struct mlx5_core_dev *dev);
 void mlx5_shd_uninit(struct mlx5_core_dev *dev);
 void mlx5_shd_lock(struct mlx5_core_dev *dev);
 void mlx5_shd_unlock(struct mlx5_core_dev *dev);
+void mlx5_shd_assert_locked(struct mlx5_core_dev *dev);
 void mlx5_shd_nested_set(struct mlx5_core_dev *dev);
 
+struct list_head *mlx5_shd_get_qos_nodes(struct mlx5_core_dev *dev);
+
 #endif /* __MLX5_SH_DEVLINK_H__ */
-- 
2.31.1

[PATCH net-next 12/14] net/mlx5: qos: Support cross-device tx scheduling

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

Up to now, rate groups could only contain vports from the same E-Switch.
This patch relaxes that restriction if the device supports it
(HCA_CAP.esw_cross_esw_sched == true) and the right conditions are met:
- Link Aggregation (LAG) is enabled.
- The E-Switches are from the same shared devlink device.

This patch does not yet enable cross-esw scheduling, it's just the last
preparatory patch.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../net/ethernet/mellanox/mlx5/core/esw/qos.c | 114 +++++++++++++-----
 1 file changed, 81 insertions(+), 33 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
index f86d7c50db42..3c8716b0644b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
@@ -50,7 +50,9 @@ struct mlx5_esw_sched_node {
 	enum sched_node_type type;
 	/* The eswitch this node belongs to. */
 	struct mlx5_eswitch *esw;
-	/* The children nodes of this node, empty list for leaf nodes. */
+	/* The children nodes of this node, empty list for leaf nodes.
+	 * Can be from multiple E-Switches.
+	 */
 	struct list_head children;
 	/* Valid only if this node is associated with a vport. */
 	struct mlx5_vport *vport;
@@ -419,6 +421,7 @@ esw_qos_vport_create_sched_element(struct mlx5_esw_sched_node *vport_node,
 	struct mlx5_esw_sched_node *parent = vport_node->parent;
 	u32 sched_ctx[MLX5_ST_SZ_DW(scheduling_context)] = {};
 	struct mlx5_core_dev *dev = vport_node->esw->dev;
+	struct mlx5_vport *vport = vport_node->vport;
 	void *attr;
 
 	if (!mlx5_qos_element_type_supported(
@@ -430,11 +433,18 @@ esw_qos_vport_create_sched_element(struct mlx5_esw_sched_node *vport_node,
 	MLX5_SET(scheduling_context, sched_ctx, element_type,
 		 SCHEDULING_CONTEXT_ELEMENT_TYPE_VPORT);
 	attr = MLX5_ADDR_OF(scheduling_context, sched_ctx, element_attributes);
-	MLX5_SET(vport_element, attr, vport_number, vport_node->vport->vport);
+	MLX5_SET(vport_element, attr, vport_number, vport->vport);
 	MLX5_SET(scheduling_context, sched_ctx, parent_element_id,
 		 parent ? parent->ix : vport_node->esw->qos.root_tsar_ix);
 	MLX5_SET(scheduling_context, sched_ctx, max_average_bw,
 		 vport_node->max_rate);
+	if (vport->dev != dev) {
+		/* The port is assigned to a node on another eswitch. */
+		MLX5_SET(vport_element, attr, eswitch_owner_vhca_id_valid,
+			 true);
+		MLX5_SET(vport_element, attr, eswitch_owner_vhca_id,
+			 MLX5_CAP_GEN(vport->dev, vhca_id));
+	}
 
 	return esw_qos_node_create_sched_element(vport_node, sched_ctx, extack);
 }
@@ -446,6 +456,7 @@ esw_qos_vport_tc_create_sched_element(struct mlx5_esw_sched_node *vport_tc_node,
 {
 	u32 sched_ctx[MLX5_ST_SZ_DW(scheduling_context)] = {};
 	struct mlx5_core_dev *dev = vport_tc_node->esw->dev;
+	struct mlx5_vport *vport = vport_tc_node->vport;
 	void *attr;
 
 	if (!mlx5_qos_element_type_supported(
@@ -457,8 +468,7 @@ esw_qos_vport_tc_create_sched_element(struct mlx5_esw_sched_node *vport_tc_node,
 	MLX5_SET(scheduling_context, sched_ctx, element_type,
 		 SCHEDULING_CONTEXT_ELEMENT_TYPE_VPORT_TC);
 	attr = MLX5_ADDR_OF(scheduling_context, sched_ctx, element_attributes);
-	MLX5_SET(vport_tc_element, attr, vport_number,
-		 vport_tc_node->vport->vport);
+	MLX5_SET(vport_tc_element, attr, vport_number, vport->vport);
 	MLX5_SET(vport_tc_element, attr, traffic_class, vport_tc_node->tc);
 	MLX5_SET(scheduling_context, sched_ctx, max_bw_obj_id,
 		 rate_limit_elem_ix);
@@ -466,6 +476,13 @@ esw_qos_vport_tc_create_sched_element(struct mlx5_esw_sched_node *vport_tc_node,
 		 vport_tc_node->parent->ix);
 	MLX5_SET(scheduling_context, sched_ctx, bw_share,
 		 vport_tc_node->bw_share);
+	if (vport->dev != dev) {
+		/* The port is assigned to a node on another eswitch. */
+		MLX5_SET(vport_tc_element, attr, eswitch_owner_vhca_id_valid,
+			 true);
+		MLX5_SET(vport_tc_element, attr, eswitch_owner_vhca_id,
+			 MLX5_CAP_GEN(vport->dev, vhca_id));
+	}
 
 	return esw_qos_node_create_sched_element(vport_tc_node, sched_ctx,
 						 extack);
@@ -1194,6 +1211,29 @@ static int esw_qos_vport_tc_check_type(enum sched_node_type curr_type,
 	return 0;
 }
 
+static bool esw_qos_validate_unsupported_tc_bw(struct mlx5_eswitch *esw,
+					       u32 *tc_bw)
+{
+	int i, num_tcs = esw_qos_num_tcs(esw->dev);
+
+	for (i = num_tcs; i < DEVLINK_RATE_TCS_MAX; i++)
+		if (tc_bw[i])
+			return false;
+
+	return true;
+}
+
+static bool esw_qos_vport_validate_unsupported_tc_bw(struct mlx5_vport *vport,
+						     u32 *tc_bw)
+{
+	struct mlx5_esw_sched_node *node = vport->qos.sched_node;
+	struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
+
+	esw = (node && node->parent) ? node->parent->esw : esw;
+
+	return esw_qos_validate_unsupported_tc_bw(esw, tc_bw);
+}
+
 static int esw_qos_vport_update(struct mlx5_vport *vport,
 				enum sched_node_type type,
 				struct mlx5_esw_sched_node *parent,
@@ -1227,6 +1267,12 @@ static int esw_qos_vport_update(struct mlx5_vport *vport,
 	if (curr_type == SCHED_NODE_TYPE_TC_ARBITER_TSAR && curr_type == type) {
 		esw_qos_set_tc_arbiter_bw_shares(vport_node, curr_tc_bw,
 						 extack);
+		if (!esw_qos_validate_unsupported_tc_bw(parent->esw,
+							curr_tc_bw)) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Unsupported traffic classes on the new device");
+			return -EOPNOTSUPP;
+		}
 	}
 
 	return err;
@@ -1575,30 +1621,6 @@ static int esw_qos_devlink_rate_to_mbps(struct mlx5_core_dev *mdev, const char *
 	return 0;
 }
 
-static bool esw_qos_validate_unsupported_tc_bw(struct mlx5_eswitch *esw,
-					       u32 *tc_bw)
-{
-	int i, num_tcs = esw_qos_num_tcs(esw->dev);
-
-	for (i = num_tcs; i < DEVLINK_RATE_TCS_MAX; i++) {
-		if (tc_bw[i])
-			return false;
-	}
-
-	return true;
-}
-
-static bool esw_qos_vport_validate_unsupported_tc_bw(struct mlx5_vport *vport,
-						     u32 *tc_bw)
-{
-	struct mlx5_esw_sched_node *node = vport->qos.sched_node;
-	struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
-
-	esw = (node && node->parent) ? node->parent->esw : esw;
-
-	return esw_qos_validate_unsupported_tc_bw(esw, tc_bw);
-}
-
 static bool esw_qos_tc_bw_disabled(u32 *tc_bw)
 {
 	int i;
@@ -1803,18 +1825,44 @@ int mlx5_esw_devlink_rate_node_del(struct devlink_rate *rate_node, void *priv,
 	return 0;
 }
 
+static int
+mlx5_esw_validate_cross_esw_scheduling(struct mlx5_eswitch *esw,
+				       struct mlx5_esw_sched_node *parent,
+				       struct netlink_ext_ack *extack)
+{
+	if (!parent || esw == parent->esw)
+		return 0;
+
+	if (!MLX5_CAP_QOS(esw->dev, esw_cross_esw_sched)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cross E-Switch scheduling is not supported");
+		return -EOPNOTSUPP;
+	}
+	if (esw->dev->shd != parent->esw->dev->shd) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cannot add vport to a parent belonging to a different device");
+		return -EOPNOTSUPP;
+	}
+	if (!mlx5_lag_is_active(esw->dev)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cross E-Switch scheduling requires LAG to be activated");
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
 static int
 mlx5_esw_qos_vport_update_parent(struct mlx5_vport *vport,
 				 struct mlx5_esw_sched_node *parent,
 				 struct netlink_ext_ack *extack)
 {
 	struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
-	int err = 0;
+	int err;
 
-	if (parent && parent->esw != esw) {
-		NL_SET_ERR_MSG_MOD(extack, "Cross E-Switch scheduling is not supported");
-		return -EOPNOTSUPP;
-	}
+	err = mlx5_esw_validate_cross_esw_scheduling(esw, parent, extack);
+	if (err)
+		return err;
 
 	if (!vport->qos.sched_node && parent) {
 		enum sched_node_type type;
-- 
2.31.1

[PATCH net-next 13/14] net/mlx5: qos: Enable cross-device scheduling

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

Enable the new devlink feature.
All rate nodes will be stored in the shared device, when available.
The shared instance lock will additionally be acquired by all rate
manipulation code to protect against concurrent execution across
different functions of the same physical device.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/devlink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
index 887adf4807d1..343fb3c52fce 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
@@ -380,6 +380,7 @@ static const struct devlink_ops mlx5_devlink_ops = {
 	.rate_node_del = mlx5_esw_devlink_rate_node_del,
 	.rate_leaf_parent_set = mlx5_esw_devlink_rate_leaf_parent_set,
 	.rate_node_parent_set = mlx5_esw_devlink_rate_node_parent_set,
+	.supported_cross_device_rate_nodes = true,
 #endif
 #ifdef CONFIG_MLX5_SF_MANAGER
 	.port_new = mlx5_devlink_sf_port_new,
-- 
2.31.1

[PATCH net-next 14/14] net/mlx5: Document devlink rates

[Tariq Toukan]

From: Cosmin Ratiu <cratiu@nvidia.com>

It seems rates were not documented in the mlx5-specific file, so add
examples on how to limit VFs and groups and also provide an example of
the intended way to achieve cross-esw scheduling.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 Documentation/networking/devlink/mlx5.rst | 33 +++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/Documentation/networking/devlink/mlx5.rst b/Documentation/networking/devlink/mlx5.rst
index 0e5f9c76e514..eb260fd1e880 100644
--- a/Documentation/networking/devlink/mlx5.rst
+++ b/Documentation/networking/devlink/mlx5.rst
@@ -405,3 +405,36 @@ User commands examples:
 
 .. note::
    This command can run over all interfaces such as PF/VF and representor ports.
+
+Rates
+=====
+
+mlx5 devices can limit transmission of individual VFs or a group of them via
+the devlink-rate API in switchdev mode.
+
+User commands examples:
+
+- Print the existing rates::
+
+    $ devlink port function rate show
+
+- Set a max tx limit on traffic from VF0::
+
+    $ devlink port function rate set pci/0000:82:00.0/1 tx_max 10Gbit
+
+- Create a rate group with a max tx limit and adding two VFs to it::
+
+    $ devlink port function rate add pci/0000:82:00.0/group1 tx_max 10Gbit
+    $ devlink port function rate set pci/0000:82:00.0/1 parent group1
+    $ devlink port function rate set pci/0000:82:00.0/2 parent group1
+
+- Same scenario, with a min guarantee of 20% of the bandwidth for the first VFs::
+
+    $ devlink port function rate add pci/0000:82:00.0/group1 tx_max 10Gbit
+    $ devlink port function rate set pci/0000:82:00.0/1 parent group1 tx_share 2Gbit
+    $ devlink port function rate set pci/0000:82:00.0/2 parent group1
+
+- Cross-device scheduling::
+
+    $ devlink port function rate add pci/0000:82:00.0/group1 tx_max 10Gbit
+    $ devlink port function rate set pci/0000:82:00.1/32769 parent pci/0000:82:00.0/group1
-- 
2.31.1

Re: [PATCH net-next 00/14] devlink and mlx5: Support cross-function rate scheduling

[Jakub Kicinski]

On Thu, 20 Nov 2025 15:09:12 +0200 Tariq Toukan wrote:
> Code dependency:
> This series should apply cleanly after the pulling of
> 'net-2025_11_19_05_03', specifically commit f94c1a114ac2 ("devlink:
> rate: Unset parent pointer in devl_rate_nodes_destroy").

repost please, we don't do dependencies

Re: [PATCH net-next 00/14] devlink and mlx5: Support cross-function rate scheduling

[Tariq Toukan]

On 21/11/2025 5:39, Jakub Kicinski wrote:
> On Thu, 20 Nov 2025 15:09:12 +0200 Tariq Toukan wrote:
>> Code dependency:
>> This series should apply cleanly after the pulling of
>> 'net-2025_11_19_05_03', specifically commit f94c1a114ac2 ("devlink:
>> rate: Unset parent pointer in devl_rate_nodes_destroy").
> 
> repost please, we don't do dependencies
> 

Hi,

I submitted the code before my weekend as we have a gap of ~1.5 working 
days (timezones + Friday). It could be utilized for collecting feedback 
on the proposed solution, or even get it accepted.

I referred to a net-* tag from the net branch, part of your regular 
process, that was about to get merged any minute. Btw it was indeed 
pulled before this response, so our series would in fact apply cleanly.

Anyway, not a big deal, I'm re-posting the series now.

Regards,
Tariq

Re: [PATCH net-next 00/14] devlink and mlx5: Support cross-function rate scheduling

[Jakub Kicinski]

On Sun, 23 Nov 2025 08:57:58 +0200 Tariq Toukan wrote:
> I submitted the code before my weekend as we have a gap of ~1.5 working 
> days (timezones + Friday). It could be utilized for collecting feedback 
> on the proposed solution, or even get it accepted.

Makes sense, our recommendation is to throw in an RFC in the subjects
in this case. Saves the back and forth.