User Manual

Features Overview and ConfigurationRev 2.3-1.0.1
Mellanox Technologies
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For example, a value of (-7) means forcing flow steering regardless of NC-SI flow steering sup-
port, disabling IPoIB flow steering support and enabling A0 static DMFS steering.
The default value of
log_num_mgm_entry_size is -10. Meaning Ethernet Flow Steering (i.e
IPoIB DMFS is disabled by default) is enabled by default if NC-SI DMFS is supported and the
HCA supports at least 64 QPs per MCG entry. Otherwise, L2 steering (B0) is used.
When using SR-IOV, flow steering is enabled if there is an adequate amount of space to store the
flow steering table for the guest/master
.
 To enable Flow Steering:
Step 1. Open the /etc/modprobe.d/mlnx.conf file.
Step 2. Set the parameter log_num_mgm_entry_size to a non positive value by writing the option
mlx4_core log_num_mgm_entry_size=<value>.
Step 3. Restart the driver
 To disable Flow Steering:
Step 1. Open the /etc/modprobe.d/mlnx.conf file.
Step 2. Remove the options mlx4_core log_num_mgm_entry_size= <value>.
Step 3. Restart the driver
3.1.11.2 Flow Steering Support
 To determine which Flow Steering features are supported:
ethtool --show-priv-flags eth4
The following output is shown:
mlx4_flow_steering_ethernet_l2: on Creating Ethernet L2 (MAC) rules is supported
mlx4_flow_steering_ipv4: on Creating IPv4 rules is supported
mlx4_flow_steering_tcp: on Creating TCP/UDP rules is supported
b1 Disable IPoIB Flow Steering When set to 1, it disables the support of IPoIB Flow Steer-
ing.
This bit should be set to 1 when "b2- Enable A0 static
DMFS steering" is used (see Section 3.1.11.3, “A0 Static
Device Managed Flow Steering”, on page 69).
b2 Enable A0 static DMFS
steering (see
Section 3.1.11.3, “A0 Static
Device Managed Flow Steer-
ing”, on page 69)
When set to 1, A0 static DMFS steering is enabled. This
bit should be set to 0 when "b1- Disable IPoIB Flow Steer-
ing" is 0.
b3 Enable DMFS only if the
HCA supports more than
64QPs per MCG entry
When set to 1, DMFS is enabled only if the HCA supports
more than 64 QPs attached to the same rule. For example,
attaching 64VFs to the same multicast address causes
64QPs to be attached to the same MCG. If the HCA sup-
ports less than 64 QPs per MCG, B0 is used.
bit Operation Description