linux-stable.git/Documentation/networking/devlink, branch master

ixd: add devlink support

2026-08-12T20:56:51+00:00

Enable initial support for the devlink interface with the ixd driver. The
ixd hardware is a single function PCIe device. So, the PCIe adapter gets
its own devlink instance to manage device-wide resources or configuration.

$ devlink dev show
pci/0000:83:00.6

$ devlink dev info pci/0000:83:00.6
pci/0000:83:00.6:
  driver ixd
  serial_number 00-a0-c9-ff-ff-23-45-67
  versions:
      fixed:
        device.type MEV
      running:
        fw.mgmt.api 2.0

Signed-off-by: Amritha Nambiar 
Reviewed-by: Michal Swiatkowski 
Reviewed-by: Maciej Fijalkowski 
Reviewed-by: Przemek Kitszel 
Tested-by: Bharath R 
Signed-off-by: Larysa Zaremba 
Signed-off-by: Tony Nguyen

net/mlx5: implement max_sfs parameter

2026-08-12T01:06:30+00:00

Implement max_sfs generic parameter to allow users to control the total
light-weight NIC subfunctions that can be created using devlink instead
of external vendor tools. A value of 0 will effectively disable creation
of new subfunction devices. A warning is sent to user-space via extack
(returning extack without error code is interpreted as a warning by
user-space tools). The maximum value is capped at U16_MAX.

Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: David Ahern 
Reviewed-by: Alexander Lobakin 
Signed-off-by: Tariq Toukan 
Link: https://patch.msgid.link/20260806073037.3001886-3-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski

devlink: add generic device max_sfs parameter

2026-08-12T01:06:30+00:00

Add a new generic devlink device parameter (max_sfs) to control if and
how many light-weight NIC subfunctions can be created. Subfunctions are
a light-weight network functions backed by an underlying PCI function.
Their lifecycle can already be managed by devlink, but currently users
cannot enable them in the device. They can be enabled/disabled only via
external vendor tools. This parameter allows subfunctions to be enabled
(>0) or disabled (0) via devlink. A subsequent patch will add support
for max_sfs to the mlx5 driver.

Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: David Ahern 
Reviewed-by: Jiri Pirko 
Reviewed-by: Aleksandr Loktionov 
Reviewed-by: Alexander Lobakin 
Signed-off-by: Tariq Toukan 
Link: https://patch.msgid.link/20260806073037.3001886-2-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski

devlink: print controller prefix for non-zero controller

2026-07-08T09:23:49+00:00

The controller prefix (c) in phys_port_name is currently restricted
to external host controllers. This layout sufficed when DPUs only had a
single local controller and one or more external host controllers.

However, newer devices can have multiple controllers within the DPU
itself, even within a single host environment. To support these
topologies, allow drivers to report the controller number regardless of
the "external" flag status. Any non-zero controller number will now be
explicitly reported, even for single-host or local DPU controllers.
Existing ports with controller=0 are unaffected.

Update documentation and kdoc to clarify that a non-zero controller
number does not require the external flag to be set.

Signed-off-by: Moshe Shemesh 
Reviewed-by: Parav Pandit 
Signed-off-by: Tariq Toukan 
Link: https://patch.msgid.link/20260702111726.816985-2-tariqt@nvidia.com
Signed-off-by: Paolo Abeni

net/mlx5: Document devlink rates

2026-07-07T09:31:27+00:00

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 
Reviewed-by: Carolina Jubran 
Signed-off-by: Tariq Toukan 
Link: https://patch.msgid.link/20260701073254.754518-15-tariqt@nvidia.com
Signed-off-by: Paolo Abeni

devlink: Allow rate node parents from other devlinks

2026-07-07T09:31:26+00:00

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.

Storing rates in the common shared ancestor is safe, because it is
reference counted by its nested devlink instances, so it's guaranteed to
outlive them. Furthermore, the shared devlink infra guarantees a given
nested devlink hierarchy is managed by the same driver.

The parent devlink from info->ctx 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.

Signed-off-by: Cosmin Ratiu 
Reviewed-by: Carolina Jubran 
Reviewed-by: Jiri Pirko 
Signed-off-by: Tariq Toukan 
Link: https://patch.msgid.link/20260701073254.754518-8-tariqt@nvidia.com
Signed-off-by: Paolo Abeni

devlink: Update nested instance locking comment

2026-07-07T09:31:26+00:00

In commit [1] a comment about nested instance locking was updated. But
there's another place where this is mentioned, so update that as well.

[1] commit 0061b5199d7c ("devlink: Reverse locking order for nested
instances")

Signed-off-by: Cosmin Ratiu 
Reviewed-by: Carolina Jubran 
Reviewed-by: Jiri Pirko 
Signed-off-by: Tariq Toukan 
Link: https://patch.msgid.link/20260701073254.754518-2-tariqt@nvidia.com
Signed-off-by: Paolo Abeni

docs: net: fix minor issues with devlink docs

2026-06-15T22:42:53+00:00

Update devlink documentation to match current code:

- describe health reporter defaults (it's currently under "callbacks"),
  best-effort auto-dump, and port-scoped reporters
- fix generic parameter names and values
- fix nested devlink setup wording and registration ordering

Link: https://patch.msgid.link/20260613165846.2913092-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski

Documentation: networking: devlink: stmmac: fix typo in phc_coarse_adj

2026-05-15T00:12:40+00:00

"Functionnal" should be "Functional".

Signed-off-by: Avinash Duduskar 
Link: https://patch.msgid.link/20260512133214.1773502-1-avinash.duduskar@gmail.com
Signed-off-by: Jakub Kicinski

devlink: Document resource scope filtering

2026-04-09T02:55:39+00:00

Document the scope parameter for devlink resource show, which allows
filtering the dump to device-level or port-level resources only.

Signed-off-by: Or Har-Toov 
Reviewed-by: Moshe Shemesh 
Signed-off-by: Tariq Toukan 
Link: https://patch.msgid.link/20260407194107.148063-13-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski