QoS Configuration

1.0
Warning

To learn more about port QoS configuration, refer to this community post.

Important

When working in Embedded Host mode, using mlnx_qos on both the host and Arm will result with undefined behavior. Users must only use mlnx_qos from the Arm. After changing the QoS settings from Arm, users must restart the mlx5 driver on host.

Warning

When configuring QoS using DCBX, the lldpad service from the DPU side must be disabled if the configurations are not done using tools other than lldpad.

This section explains how to configure QoS group and settings using devlink located under /opt/mellanox/iproute2/sbin/. It is applicable to host PF/VF and Arm side SFs. The following uses VF as example.

The settings of a QoS group include creating/deleting a QoS group and modifying its tx_max and tx_share values. The settings of VF QoS include modifying its tx_max and tx_share values, assigning a VF to a QoS group, and unassigning a VF from a QoS group. This section focuses on the configuration syntax.

Please refer to section "Limit and Bandwidth Share Per VF" in the MLNX_OFED User Manual for detailed explanation on vPort QoS behaviors.

devlink port function rate add <DEV>/<GROUP_NAME>

Adds a QoS group.

Syntax Description

DEV/GROUP_NAME

Specifies group name in string format

Example

This command adds a new QoS group named "12_group" under device "pci/0000:03:00.0":

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devlink port function rate add pci/0000:03:00.0/12_group

Notes

devlink port function rate del <DEV>/<GROUP_NAME>

Deletes a QoS group.

Syntax Description

DEV/GROUP_NAME

Specifies group name in string format

Example

This command deletes QoS group "12_group" from device "pci/0000:03:00.0":

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devlink port function rate del pci/0000:03:00.0/12_group

Notes

devlink port function rate set {<DEV>/<GROUP_NAME> | <DEV>/<PORT_INDEX>} tx_max <TX_MAX> [tx_share <TX_SHARE>]

Sets tx_max and tx_share for QoS group or devlink port.

Syntax Description

DEV/GROUP_NAME

Specifies the group name to operate on

DEV/PORT_INDEX

Specifies the devlink port to operate on

TX_MAX

tx_max bandwidth in Mb/s

TX_SHARE

tx_share bandwidth in Mb/s

Example

This command sets tx_max to 2000Mb/s and tx_share to 500Mb/s for the "12_group" QoS group:

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devlink port function rate set pci/0000:03:00.0/12_group tx_max 2000Mbps tx_share 500Mbps

This command sets tx_max to 2000Mb/s and tx_share to 500Mb/s for the VF represented by port index 196609:

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devlink port function rate set pci/0000:03:00.0/196609 tx_max 200Mbps tx_share 50Mbps

This command displays a mapping between VF devlink ports and netdev names:

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$ devlink port

In the output of this command, VFs are indicated by flavour pcivf.

Notes

devlink port function rate set <DEV>/<PORT_INDEX> {parent <PARENT_GROUP_NAME>}

Assigns devlink port to a QoS group.

Syntax Description

DEV/PORT_INDEX

Specifies the devlink port to operate on

PARENT_GROUP_NAME

parent group name in string format

Example

This command assigns this function to the QoS group "12_group":

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devlink port function rate set pci/0000:03:00.0/196609 parent 12_group

Notes

devlink port function rate set noparent

devlink port function rate set <DEV>/<PORT_INDEX> noparent

Ungroups a devlink port.

Syntax Description

DEV/PORT_INDEX

Specifies the devlink port to operate on

Example

This command ungroups this function:

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devlink port function rate set pci/0000:03:00.0/196609 noparent

Notes


devlink port function rate show [<DEV>/<GROUP_NAME> | <DEV>/<PORT_INDEX>]

Displays QoS information QoS group or devlink port.

Syntax Description

DEV/GROUP_NAME

Specifies the group name to display

DEV/PORT_INDEX

Specifies the devlink port to display

Example

This command displays the QoS info of all QoS groups and devlink ports on the system:

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devlink port function rate show pci/0000:03:00.0/12_group type node tx_max 2000Mbps tx_share 500Mbps pci/0000:03:00.0/196609 type leaf tx_max 200Mbps tx_share 50Mbps parent 12_group

This command displays QoS info of 12_group:

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devlink port function rate show pci/0000:03:00.0/12_group pci/0000:03:00.0/12_group type node tx_max 2000Mbps tx_share 500Mbps

Notes

If a QoS group name or devlink port are not specified, all QoS groups and devlink ports are displayed.

© Copyright 2023, NVIDIA. Last updated on Oct 3, 2023.