To learn more about port QoS configuration, refer to this community post.
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.
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.
Rate Limiting Host PF and VF
From the Arm, users may limit the transmit rate of the PF in the host. For example, these commands limit the transmit rate of the PF of ECPF's p0 to 1000 Mbps and the virtual function #0 to 500 Mbps:
echo 1000 > /sys/class/net/p0/smart_nic/pf/max_tx_rate echo 500 > /sys/class/net/p0/smart_nic/vf0/max_tx_rate
To set the minimum transmit rate of the PF of ECPF's p0 to 100 Mbps and of VF0 to 50 Mbps, run the following commands:
echo 100 > /sys/class/net/p0/smart_nic/pf/min_tx_rate" echo 50 > /sys/class/net/p0/smart_nic/vf0/min_tx_rate"
The minimum transmit rate is implemented according to weight setting and round robin arbitration. Thus, this configuration only ensures that the minimum transmit rate of the PF is double that of VF0.
Rate Limiting SF
This section explains how to configure QoS group and SF QoS settings using mlxdevm, which located under directory /opt/mellanox/iproute2/sbin/.
The settings of a QoS group include creating/deleting a QoS group and modifying its tx_max and tx_share values. The settings of SF QoS include modifying its tx_max and tx_share values, assigning an SF to a QoS group, and unassigning an SF 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.
mlxdevm Commands
mlxdevm port function rate add
mlxdevm 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": mlxdevm port function rate add pci/0000:03:00.0/12_group | |
| Notes | ||
mlxdevm port function rate del
mlxdevm 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": mlxdevm port function rate del pci/0000:03:00.0/12_group | |
| Notes | ||
mlxdevm port function rate set tx_max tx_share
mlxdevm port function rate set {<DEV>/<GROUP_NAME> | <DEV>/<PORT_INDEX>} tx_max <TX_MAX> [tx_share <TX_SHARE>] Sets | ||
| Syntax Description | DEV/GROUP_NAME | Specifies the group name to operate on |
| DEV/PORT_INDEX | Specifies the mlxdevm port to operate on | |
| TX_MAX | tx_max bandwidth in Mb/s | |
| TX_SHARE | tx_share bandwidth in Mb/s | |
| Example | This command sets mlxdevm port function rate set pci/0000:03:00.0/12_group tx_max 900 This command sets mlxdevm port function rate set pci/0000:03:00.0/229376 tx_max 2000 tx_share 500 | |
| Notes | ||
mlxdevm port function rate set parent
mlxdevm port function rate set <DEV>/<PORT_INDEX> {parent <PARENT_GROUP_NAME>} Assigns mlxdevm port to a QoS group. | ||
| Syntax Description | DEV/PORT_INDEX | Specifies the mlxdevm 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": mlxdevm port function rate set pci/0000:03:00.0/229376 parent 12_group | |
| Notes | ||
mlxdevm port function rate set noparent
mlxdevm port function rate set <DEV>/<PORT_INDEX> noparent Ungroups a mlxdevm port. | ||
| Syntax Description | DEV/PORT_INDEX | Specifies the mlxdevm port to operate on |
| Example | This command ungroups this function: mlxdevm port function rate set pci/0000:03:00.0/229376 noparent | |
| Notes | ||
mlxdevm port function rate show
mlxdevm port function rate show [<DEV>/<GROUP_NAME> | <DEV>/<PORT_INDEX>] Displays QoS information QoS group or mlxdevm port. | ||
| Syntax Description | DEV/GROUP_NAME | Specifies the group name to display |
| DEV/PORT_INDEX | Specifies the mlxdevm port to display | |
| Example | This command displays the QoS info of all QoS groups and mlxdevm ports on the system: mlxdevm port function rate show pci/0000:03:00.0/12_group type node tx_max 1000 tx_share 200 pci/0000:03:00.0/229376 type leaf tx_max 2000 tx_share 500 parent 12_group This command displays QoS info of 12_group: mlxdevm port function rate show pci/0000:03:00.0/12_group pci/0000:03:00.0/12_group type node tx_max 1000 tx_share 200 | |
| Notes | If a QoS group name or mlxdevm port are not specified, all QoS groups and mlxdevm ports are displayed. | |
Rate Limiting VF Group
This section explains how to configure QoS group and VF QoS settings using devlink located under /opt/mellanox/iproute2/sbin/.
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 Commands
devlink port function rate add
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": devlink port function rate add pci/0000:03:00.0/12_group | |
| Notes | ||
devlink port function rate del
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": devlink port function rate del pci/0000:03:00.0/12_group | |
| Notes | ||
devlink port function rate set tx_max tx_share
devlink port function rate set {<DEV>/<GROUP_NAME> | <DEV>/<PORT_INDEX>} tx_max <TX_MAX> [tx_share <TX_SHARE>] Sets | ||
| 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 devlink port function rate set pci/0000:03:00.0/12_group tx_max 2000Mbps tx_share 500Mbps This command sets devlink port function rate set pci/0000:03:00.0/196609 tx_max 200Mbps tx_share 50Mbps $ devlink port flavour pcivf. | |
| Notes | ||
devlink port function rate set parent
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": 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: devlink port function rate set pci/0000:03:00.0/196609 noparent | |
| Notes | ||
devlink port function rate show
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: 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: 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. | |
