36. OCTEON TX Poll Mode driver

The OCTEON TX ETHDEV PMD (librte_pmd_octeontx) provides poll mode ethdev driver support for the inbuilt network device found in the Cavium OCTEON TX SoC family as well as their virtual functions (VF) in SR-IOV context.

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

36.1. Features

Features of the OCTEON TX Ethdev PMD are:

  • Packet type information
  • Promiscuous mode
  • Port hardware statistics
  • Jumbo frames
  • Link state information
  • SR-IOV VF
  • Multiple queues for TX
  • Lock-free Tx queue
  • HW offloaded ethdev Rx queue to eventdev event queue packet injection

36.2. Supported OCTEON TX SoCs

  • CN83xx

36.3. Unsupported features

The features supported by the device and not yet supported by this PMD include:

  • Receive Side Scaling (RSS)
  • Scattered and gather for TX and RX
  • Ingress classification support
  • Egress hierarchical scheduling, traffic shaping, and marking

36.4. Prerequisites

See OCTEON TX Board Support Package for setup information.

36.5. Pre-Installation Configuration

36.5.1. 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_OCTEONTX_PMD (default y)

    Toggle compilation of the librte_pmd_octeontx driver.

36.5.2. Driver compilation and testing

Refer to the document compiling and testing a PMD for a NIC for details.

To compile the OCTEON TX PMD for Linux arm64 gcc target, run the following make command:

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

  1. Running testpmd:

    Follow instructions available in the document compiling and testing a PMD for a NIC to run testpmd.

    Example output:

    ./arm64-thunderx-linux-gcc/app/testpmd -c 700 \
          --base-virtaddr=0x100000000000 \
          --mbuf-pool-ops-name="octeontx_fpavf" \
          --vdev='event_octeontx' \
          --vdev='eth_octeontx,nr_port=2' \
          -- --rxq=1 --txq=1 --nb-core=2 \
          --total-num-mbufs=16384 -i
.....
EAL: Detected 24 lcore(s)
EAL: Probing VFIO support...
EAL: VFIO support initialized
.....
EAL: PCI device 0000:07:00.1 on NUMA socket 0
EAL:   probe driver: 177d:a04b octeontx_ssovf
.....
EAL: PCI device 0001:02:00.7 on NUMA socket 0
EAL:   probe driver: 177d:a0dd octeontx_pkivf
.....
EAL: PCI device 0001:03:01.0 on NUMA socket 0
EAL:   probe driver: 177d:a049 octeontx_pkovf
.....
PMD: octeontx_probe(): created ethdev eth_octeontx for port 0
PMD: octeontx_probe(): created ethdev eth_octeontx for port 1
.....
Configuring Port 0 (socket 0)
Port 0: 00:0F:B7:11:94:46
Configuring Port 1 (socket 0)
Port 1: 00:0F:B7:11:94:47
.....
Checking link statuses...
Port 0 Link Up - speed 40000 Mbps - full-duplex
Port 1 Link Up - speed 40000 Mbps - full-duplex
Done
testpmd>

36.6. Initialization

The OCTEON TX ethdev pmd is exposed as a vdev device which consists of a set of PKI and PKO PCIe VF devices. On EAL initialization, PKI/PKO 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 PKI/PKO PCIe VF device to DPDK by

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

36.6.1. Device arguments

Each ethdev port is mapped to a physical port(LMAC), Application can specify the number of interesting ports with nr_ports argument.

36.6.2. Dependency

eth_octeontx pmd is depend on event_octeontx eventdev device and octeontx_fpavf external mempool handler.

Example:

./your_dpdk_application --mbuf-pool-ops-name="octeontx_fpavf" \
            --vdev='event_octeontx' \
            --vdev="eth_octeontx,nr_port=2"

36.7. Limitations

36.7.1. octeontx_fpavf external mempool handler dependency

The OCTEON TX SoC family NIC has inbuilt HW assisted external mempool manager. This driver will only work with octeontx_fpavf external mempool handler as it is the most performance effective way for packet allocation and Tx buffer recycling on OCTEON TX SoC platform.

36.7.2. CRC striping

The OCTEON TX SoC family NICs strip the CRC for every packets coming into the host interface irrespective of the offload configuration.

36.7.3. Maximum packet length

The OCTEON TX SoC family NICs support a maximum of a 32K jumbo frame. The value is fixed and cannot be changed. So, even when the rxmode.max_rx_pkt_len member of struct rte_eth_conf is set to a value lower than 32k, frames up to 32k bytes can still reach the host interface.