Tribblix: manual page: mlxcx.4d

MLXCX(4D) Devices MLXCX(4D)

NAME

mlxcx - Mellanox ConnectX-4/5/6 Ethernet controller driver

SYNOPSIS

/dev/net/mlxcx*

DESCRIPTION

The mlxcx driver is a GLDv3 NIC driver for the ConnectX-4, ConnectX-4
Lx, ConnectX-5 and ConnectX-6 families of ethernet controllers from
Mellanox. It supports the Data Link Provider Interface, dlpi(4P).

This driver supports:

- Jumbo frames up to 9000 bytes.

- Checksum offload for TCP, UDP, IPv4 and IPv6.

- Group support with VLAN and MAC steering to avoid software
classification when using VNICs.

- Promiscuous access via snoop(8) and dlpi(4P)

- LED control

- Transceiver information

- Internal temperature sensors

At this time, the driver does not support Large Send Offload (LSO),
energy efficient Ethernet (EEE), or the use of flow control through
hardware pause frames.

CONFIGURATION

The mlxcx.conf file contains user configurable parameters, including
the ability to set the number of rings and groups advertised to MAC,
the sizes of rings and groups, and the maximum number of MAC address
filters available.

PROPERTIES

The driver supports the following device properties which may be tuned
through its driver.conf file, /kernel/drv/mlxcx.conf. These properties
cannot be changed after the driver has been attached.

These properties are not considered stable at this time, and may
change.

eq_size_shift
Minimum: 2 | Maximum: device dependent (up to 255)

The eq_size_shift property determines the number of entries on
Event Queues for the device. The number of entries is
calculated as (1 << eq_size_shift), so a value of 9 would mean
512 entries are created on each Event Queue. The default value
is 9.

cq_size_shift
Minimum: 2 | Maximum: device dependent (up to 255)

The cq_size_shift property determines the number of entries on
Completion Queues for the device. The number of entries is
calculated as (1 << cq_size_shift), so a value of 9 would mean
512 entries are created on each Event Queue. The default value
is device dependent, 10 for devices with maximum supported
speed of 10Gb/s or less and 12 for devices with higher
supported speeds. This should be kept very close to the value
set for rq_size_shift and sq_size_shift.

rq_size_shift
Minimum: 2 | Maximum: device dependent (up to 255)

The rq_size_shift property determines the number of descriptors
on Receive Queues for the device. The number of descriptors is
calculated as (1 << rq_size_shift), so a value of 9 would mean
512 descriptors are created on each Receive Queue. This sets
the number of packets on RX rings advertised to MAC. The
default value is device dependent, 10 for devices with maximum
supported speed of 10Gb/s or less and 12 for devices with
higher supported speeds.

sq_size_shift
Minimum: 2 | Maximum: device dependent (up to 255)

The sq_size_shift property determines the number of descriptors
on Send Queues for the device. The number of descriptors is
calculated as (1 << sq_size_shift), so a value of 9 would mean
512 descriptors are created on each Send Queue. This sets the
number of packets on RX rings advertised to MAC. The default
value is device dependent, 11 for devices with maximum
supported speed of 10Gb/s or less and 13 for devices with
higher supported speeds. Note that large packets often occupy
more than one descriptor slot on the SQ, so it is sometimes a
good idea to increase this if using a large MTU.

tx_ngroups
Minimum: 1 | Maximum: device dependent

The tx_ngroups property determines the number of TX groups
advertised to MAC. The default value is 1.

tx_nrings_per_group
Minimum: 1 | Maximum: device dependent

The tx_nrings_per_group property determines the number of rings
in each TX group advertised to MAC. The default value is 64.

rx_ngroups_large
Minimum: 1 | Maximum: device dependent

The rx_ngroups_large property determines the number of "large"
RX groups advertised to MAC. The size of "large" RX groups is
set by the rx_nrings_per_large_group property. The default
value is 2.

rx_nrings_per_large_group
Minimum: 1 | Maximum: device dependent

The rx_nrings_per_large_group property determines the number of
rings in each "large" RX group advertised to MAC. The number
of such groups is determined by the rx_ngroups_large property.
The default value is 16.

rx_ngroups_small
Minimum: 1 | Maximum: device dependent

The rx_ngroups_small property determines the number of "small"
RX groups advertised to MAC. The size of "small" RX groups is
set by the rx_nrings_per_small_group property. It is
recommended to use many small groups when using a large number
of VNICs on top of the NIC (e.g. on a system with many zones).
The default value is 256.

rx_nrings_per_small_group
Minimum: 1 | Maximum: device dependent

The rx_nrings_per_small_group property determines the number of
rings in each "small" RX group advertised to MAC. The number
of such groups is determined by the rx_ngroups_small property.
The default value is 4.

ftbl_root_size_shift
Minimum: 4 | Maximum: device dependent

The ftbl_root_size_shift property determines the number of flow
table entries on the root flow table, and therefore how many
MAC addresses can be filtered into groups across the entire
NIC. The number of flow entries is calculated as (1 <<
ftbl_root_size_shift), so a value of 9 would mean 512 entries
are created in the root flow table. The default value is 12.

cqemod_period_usec
Minimum: 1 | Maximum: 65535

The cqemod_period_usec property determines the maximum delay
after a completion event has occurred before an event queue
entry (and thus an interrupt) is generated. The delay is
measured in microseconds. The default value is 50.

cqemod_count
Minimum: 1 | Maximum: 65535

The cqemod_count property determines the maximum number of
completion events that can have occurred before an event queue
entry (and thus an interrupt) is generated. The default value
is 80% of the CQ size.

intrmod_period_usec
Minimum: 1 | Maximum: 65535

The intrmod_period_usec property determines the maximum delay
after an event queue entry has been generated before an
interrupt is raised. The delay is measured in microseconds.
The default value is 10.

tx_bind_threshold
Minimum: 1 | Maximum: 65535

The tx_bind_threshold property determines the minimum number of
bytes in a packet before the driver uses
ddi_dma_addr_bind_handle(9F) to bind the packet memory for DMA,
rather than copying the memory as it does for small packets.
DMA binds are expensive and involve taking locks in the PCI
nexus driver, so it is seldom worth using them for small
packets. The default value is 2048.

rx_limit_per_completion
Minimum: 16 | Maximum: 4096

The rx_limit_per_completion property determines the maximum
number of packets that will be processed on a given completion
ring during a single interrupt. This is done to try and
guarantee some amount of liveness in the system. The default
value is 256.

rx_p50_loan_min_size
Minimum: 0 | Maximum: MTU

The rx_p50_loan_min_size property determines the minimum size
of packet buffers allowed to be loaned to MAC when the ring has
reached >=50% of its buffers already on loan. Packet buffers
larger than this value will be copied. At <50% of ring buffers
on loan, all buffers will be loaned. At >=75% of buffers on
loan, all packets will be copied instead to ensure ring
availability. The default value is 256.

FILES