ENA(4D) 4D ENA(4D)

NAME


ena - Driver for the AWS Elastic Network Adapter

SYNOPSIS


/dev/net/ena*

DESCRIPTION


The ena driver is a GLDv3 NIC driver for the AWS Elastic Network Adapter
family of virtual devices. The driver supports:

- Jumbo frames up to 9216 bytes.

- Multiple Rx and Tx rings.

By design, this driver does not support VNICs. A given ENA device can only
ever receive traffic for a single unicast MAC address and IP address
combination, as determined by the AWS configuration. There is no support
for promiscuous mode, or for receiving traffic for additional unicast or
multicast addresses.

CONFIGURATION


The ena.conf file contains user configurable parameters, each of which is
described below. This file is read when an ENA device is found and an
instance of the driver is attached to it. Changes made to this file do not
affect running instances. Only instances attached after the changes will
see the effects of those changes. Therefore, if you want your change to
take effect on a running instance, you must somehow reload it. That could
be done by a manual reloading of the driver or a system reboot.

PROPERTIES


The configuration file can be found at /kernel/drv/ena.conf.

rx_queue_num_descs
Minimum: 64 | Maximum: device dependent
Default: device maximum

The rx_queue_num_descs property determines the number of
descriptors provided by the Rx queue. Currently a single
descriptor is equal to a single packet, but in the future it may be
that a single packet consumes multiple descriptors.

rx_queue_intr_limit
Minimum: 16 | Maximum: 4096
Default: 256

The rx_queue_intr_limit property determines the number frames an Rx
interrupt will attempt to process before returning and claiming the
interrupt. This is meant to keep the ENA Rx interrupt handler from
consuming too much system time. In general, when a NIC becomes
saturated with packets, the MAC layer will switch the driver into
polling mode to reduce interrupt load.

tx_queue_num_descs
Minimum: 64 | Maximum: device dependent
Default: device maximum

The tx_queue_num_descs property determines the number of
descriptors provided by the Tx queue. Currently a single
descriptor is equal to a single packet, but in the future it may be
that a single packet consumes multiple descriptors.

FILES


/kernel/drv/amd64/ena Device driver (x86)

/kernel/drv/ena.conf Driver configuration file containing
user-configurable options

INTERFACE STABILITY


The tunables in ena.conf are considered Evolving and may change in the
future.

SEE ALSO


dlpi(4P), driver.conf(5), dladm(8), snoop(8)

OmniOS November 17, 2021 OmniOS