3. OCTEONTX SSOVF Eventdev Driver

The OCTEONTX SSOVF PMD (librte_pmd_octeontx_ssovf) provides poll mode eventdev driver support for the inbuilt event device found in the Cavium OCTEONTX SoC family as well as their virtual functions (VF) in SR-IOV context.

More information can be found at Cavium, Inc Official Website.

3.1. Features

Features of the OCTEONTX SSOVF PMD are:

  • 64 Event queues
  • 32 Event ports
  • HW event scheduler
  • Supports 1M flows per event queue
  • Flow based event pipelining
  • Flow pinning support in flow based event pipelining
  • Queue based event pipelining
  • Supports ATOMIC, ORDERED, PARALLEL schedule types per flow
  • Event scheduling QoS based on event queue priority
  • Open system with configurable amount of outstanding events
  • HW accelerated dequeue timeout support to enable power management
  • SR-IOV VF

3.2. Supported OCTEONTX SoCs

  • CN83xx

3.3. Prerequisites

There are three main pre-perquisites for executing SSOVF PMD on a OCTEONTX compatible board:

  1. OCTEONTX Linux kernel PF driver for Network acceleration HW blocks

    The OCTEONTX Linux kernel drivers (including the required PF driver for the SSOVF) are available on Github at octeontx-kmod along with build, install and dpdk usage instructions.

  2. ARM64 Tool Chain

    For example, the aarch64 Linaro Toolchain, which can be obtained from here.

  3. Rootfile system

    Any aarch64 supporting filesystem can be used. For example, Ubuntu 15.10 (Wily) or 16.04 LTS (Xenial) userland which can be obtained from http://cdimage.ubuntu.com/ubuntu-base/releases/16.04/release/ubuntu-base-16.04.1-base-arm64.tar.gz.

    As an alternative method, SSOVF PMD can also be executed using images provided as part of SDK from Cavium. The SDK includes all the above prerequisites necessary to bring up a OCTEONTX board.

    SDK and related information can be obtained from: Cavium support site.

3.4. Pre-Installation Configuration

3.4.1. Config File Options

The following options can be modified in the config file. Please note that enabling debugging options may affect system performance.

  • CONFIG_RTE_LIBRTE_PMD_OCTEONTX_SSOVF (default y)

    Toggle compilation of the librte_pmd_octeontx_ssovf driver.

  • CONFIG_RTE_LIBRTE_PMD_OCTEONTX_SSOVF_DEBUG (default n)

    Toggle display of generic debugging messages

3.4.2. Driver Compilation

To compile the OCTEONTX SSOVF PMD for Linux arm64 gcc target, run the following make command:

cd <DPDK-source-directory>
make config T=arm64-thunderx-linuxapp-gcc install

3.5. Initialization

The octeontx eventdev is exposed as a vdev device which consists of a set of SSO group and work-slot PCIe VF devices. On EAL initialization, SSO PCIe VF devices will be probed and then the vdev device can be created from the application code, or from the EAL command line based on the number of probed/bound SSO PCIe VF device to DPDK by

  • Invoking rte_vdev_init("event_octeontx") from the application
  • Using --vdev="event_octeontx" in the EAL options, which will call rte_vdev_init() internally

Example:

./your_eventdev_application --vdev="event_octeontx"

3.6. Limitations

3.6.1. Burst mode support

Burst mode is not supported. Dequeue and Enqueue functions accepts only single event at a time.