[net-next,10/10] net/mlx5: Document devlink rates and cross-esw scheduling

Commit Message

Tariq Toukan Feb. 13, 2025, 6:01 p.m. UTC

From: Cosmin Ratiu <[e-mail]>

Extend the devlink-port documentation with a mention that parents can be
from different devices.

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 <[e-mail]>
Reviewed-by: Carolina Jubran <[e-mail]>
Signed-off-by: Tariq Toukan <[e-mail]>
---
 .../networking/devlink/devlink-port.rst       |  2 ++
 Documentation/networking/devlink/mlx5.rst     | 33 +++++++++++++++++++
 2 files changed, 35 insertions(+)

Patch

diff --git a/Documentation/networking/devlink/devlink-port.rst b/Documentation/networking/devlink/devlink-port.rst
index 9d22d41a7cd1..1d9e5839eef4 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.
 
 ``tx_priority`` and ``tx_weight`` can be used simultaneously. In that case
 nodes with the same priority form a WFQ subgroup in the sibling group
diff --git a/Documentation/networking/devlink/mlx5.rst b/Documentation/networking/devlink/mlx5.rst
index 7febe0aecd53..61e76da36faf 100644
--- a/Documentation/networking/devlink/mlx5.rst
+++ b/Documentation/networking/devlink/mlx5.rst
@@ -298,3 +298,36 @@  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 group1