User Manual

Rev 2.3-1.0.1

Mellanox Technologies

The mlx4 driver supports only a subset of the flow specification the ethtool API defines. Ask-

ing for an unsupported flow specification will result with an “invalid value” failure.

The following are the flow specific parameters:

ether tcp4/udp4 ip4

Mandatory dst src-ip/dst-ip

Optional vlan src-ip, dst-ip, src-

port, dst-port, vlan

src-ip, dst-ip, vlan

• RFS

RFS is an in-kernel-logic responsible for load balancing between CPUs by attaching flows to

CPUs that are used by flow’

s owner applications. This domain allows the RFS mechanism to

use the flow steering infrastructure to support the RFS logic by implementing the

ndo_rx_flow_steer, which, in turn, calls the underlying flow steering mechanism with the

RFS domain.

Enabling the RFS requires enabling the

‘ntuple’ flag via the ethtool,

For example, to enable ntuple for eth0, run:

ethtool -K eth0 ntuple on

RFS requires the kernel to be compiled with the CONFIG_RFS_ACCEL option. This options is

available in kernels 2.6.39 and above. Furthermore, RFS requires Device Managed Flow Steer-

ing support.

RFS cannot function if LRO is enabled. LRO can be disabled via ethtool.

• All of the rest

The lowest priority domain serves the following users:

• The mlx4 Ethernet driver attaches its unicast and multicast MACs addresses to its QP

using L2 flow specifications

• The mlx4 ipoib driver when it attaches its QP to his configured GIDS

Fragmented UDP traffic cannot be steered. It is treated as 'other' protocol by hardware

(from the first packet) and not considered as UDP traffic.

We recommend using libibverbs v2.0-3.0.0 and libmlx4 v2.0-3.0.0 and higher as

of MLNX_OFED v2.0-3.0.0 due to API changes.