12. CNXK Poll Mode driver

The CNXK ETHDEV PMD (librte_net_cnxk) provides poll mode ethdev driver support for the inbuilt network device found in Marvell OCTEON CN9K/CN10K SoC family as well as for their virtual functions (VF) in SR-IOV context.

More information can be found at Marvell Official Website.

12.1. Features

Features of the CNXK Ethdev PMD are:

  • Packet type information

  • Promiscuous mode

  • Jumbo frames

  • SR-IOV VF

  • Lock-free Tx queue

  • Multiple queues for TX and RX

  • Receiver Side Scaling (RSS)

  • MAC filtering

  • Generic flow API

  • Inner and Outer Checksum offload

  • Port hardware statistics

  • Link state information

  • Link flow control

  • MTU update

  • Scatter-Gather IO support

  • Vector Poll mode driver

  • Debug utilities - Context dump and error interrupt support

  • Support Rx interrupt

  • Inline IPsec processing support

  • Ingress meter support

12.2. Prerequisites

See Marvell cnxk platform guide for setup information.

12.3. Driver compilation and testing

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

  1. Running testpmd:

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

    Example output:

    ./<build_dir>/app/dpdk-testpmd -c 0xc -a 0002:02:00.0 -- --portmask=0x1 --nb-cores=1 --port-topology=loop --rxq=1 --txq=1
EAL: Detected 4 lcore(s)
EAL: Detected 1 NUMA nodes
EAL: Multi-process socket /var/run/dpdk/rte/mp_socket
EAL: Selected IOVA mode 'VA'
EAL: No available hugepages reported in hugepages-16777216kB
EAL: No available hugepages reported in hugepages-2048kB
EAL: Probing VFIO support...
EAL: VFIO support initialized
EAL:   using IOMMU type 1 (Type 1)
[ 2003.202721] vfio-pci 0002:02:00.0: vfio_cap_init: hiding cap 0x14@0x98
EAL: Probe PCI driver: net_cn10k (177d:a063) device: 0002:02:00.0 (socket 0)
PMD: RoC Model: cn10k
EAL: No legacy callbacks, legacy socket not created
testpmd: create a new mbuf pool <mb_pool_0>: n=155456, size=2176, socket=0
testpmd: preferred mempool ops selected: cn10k_mempool_ops
Configuring Port 0 (socket 0)
PMD: Port 0: Link Up - speed 25000 Mbps - full-duplex

Port 0: link state change event
Port 0: 96:D4:99:72:A5:BF
Checking link statuses...
Done
No commandline core given, start packet forwarding
io packet forwarding - ports=1 - cores=1 - streams=1 - NUMA support enabled, MP allocation mode: native
Logical Core 3 (socket 0) forwards packets on 1 streams:
  RX P=0/Q=0 (socket 0) -> TX P=0/Q=0 (socket 0) peer=02:00:00:00:00:00

  io packet forwarding packets/burst=32
  nb forwarding cores=1 - nb forwarding ports=1
  port 0: RX queue number: 1 Tx queue number: 1
    Rx offloads=0x0 Tx offloads=0x10000
    RX queue: 0
      RX desc=4096 - RX free threshold=0
      RX threshold registers: pthresh=0 hthresh=0  wthresh=0
      RX Offloads=0x0
    TX queue: 0
      TX desc=512 - TX free threshold=0
      TX threshold registers: pthresh=0 hthresh=0  wthresh=0
      TX offloads=0x0 - TX RS bit threshold=0
Press enter to exit

12.4. Runtime Config Options

  • Rx&Tx scalar mode enable (default 0)

    PMD supports both scalar and vector mode, it may be selected at runtime using scalar_enable devargs parameter.

  • RSS reta size (default 64)

    RSS redirection table size may be configured during runtime using reta_size devargs parameter.

    For example:

    -a 0002:02:00.0,reta_size=256

    With the above configuration, reta table of size 256 is populated.

  • Flow priority levels (default 3)

    RTE Flow priority levels can be configured during runtime using flow_max_priority devargs parameter.

    For example:

    -a 0002:02:00.0,flow_max_priority=10

    With the above configuration, priority level was set to 10 (0-9). Max priority level supported is 32.

  • Reserve Flow entries (default 8)

    RTE flow entries can be pre allocated and the size of pre allocation can be selected runtime using flow_prealloc_size devargs parameter.

    For example:

    -a 0002:02:00.0,flow_prealloc_size=4

    With the above configuration, pre alloc size was set to 4. Max pre alloc size supported is 32.

  • Max SQB buffer count (default 512)

    Send queue descriptor buffer count may be limited during runtime using max_sqb_count devargs parameter.

    For example:

    -a 0002:02:00.0,max_sqb_count=64

    With the above configuration, each send queue’s descriptor buffer count is limited to a maximum of 64 buffers.

  • Switch header enable (default none)

    A port can be configured to a specific switch header type by using switch_header devargs parameter.

    For example:

    -a 0002:02:00.0,switch_header="higig2"

    With the above configuration, higig2 will be enabled on that port and the traffic on this port should be higig2 traffic only. Supported switch header types are “chlen24b”, “chlen90b”, “dsa”, “exdsa”, “higig2” and “vlan_exdsa”.

  • RSS tag as XOR (default 0)

    The HW gives two options to configure the RSS adder i.e

    • rss_adder<7:0> = flow_tag<7:0> ^ flow_tag<15:8> ^ flow_tag<23:16> ^ flow_tag<31:24>

    • rss_adder<7:0> = flow_tag<7:0>

    Latter one aligns with standard NIC behavior vs former one is a legacy RSS adder scheme used in OCTEON TX2 products.

    By default, the driver runs in the latter mode. Setting this flag to 1 to select the legacy mode.

    For example to select the legacy mode(RSS tag adder as XOR):

    -a 0002:02:00.0,tag_as_xor=1

  • Max SPI for inbound inline IPsec (default 255)

    Max SPI supported for inbound inline IPsec processing can be specified by ipsec_in_max_spi devargs parameter.

    For example:

    -a 0002:02:00.0,ipsec_in_max_spi=128

    With the above configuration, application can enable inline IPsec processing for 128 inbound SAs (SPI 0-127).

  • Max SA's for outbound inline IPsec (default 4096)

    Max number of SA’s supported for outbound inline IPsec processing can be specified by ipsec_out_max_sa devargs parameter.

    For example:

    -a 0002:02:00.0,ipsec_out_max_sa=128

    With the above configuration, application can enable inline IPsec processing for 128 outbound SAs.

  • Outbound CPT LF queue size (default 8200)

    Size of Outbound CPT LF queue in number of descriptors can be specified by outb_nb_desc devargs parameter.

    For example:

      -a 0002:02:00.0,outb_nb_desc=16384

With the above configuration, Outbound CPT LF will be created to accommodate
at max 16384 descriptors at any given time.

  • Outbound CPT LF count (default 1)

    Number of CPT LF’s to attach for Outbound processing can be specified by outb_nb_crypto_qs devargs parameter.

    For example:

    -a 0002:02:00.0,outb_nb_crypto_qs=2

    With the above configuration, two CPT LF’s are setup and distributed among all the Tx queues for outbound processing.

  • Force using inline ipsec device for inbound (default 0)

    In CN10K, in event mode, driver can work in two modes,

    1. Inbound encrypted traffic received by probed ipsec inline device while plain traffic post decryption is received by ethdev.

    2. Both Inbound encrypted traffic and plain traffic post decryption are received by ethdev.

    By default event mode works without using inline device i.e mode 2. This behaviour can be changed to pick mode 1 by using force_inb_inl_dev devargs parameter.

    For example:

    -a 0002:02:00.0,force_inb_inl_dev=1 -a 0002:03:00.0,force_inb_inl_dev=1

    With the above configuration, inbound encrypted traffic from both the ports is received by ipsec inline device.

  • Inline IPsec device channel and mask (default none)

    Set channel and channel mask configuration for the inline IPSec device. This will be used when creating flow rules with RTE_FLOW_ACTION_TYPE_SECURITY action.

    By default, RTE Flow API sets the channel number of the port on which the rule is created in the MCAM entry and matches it exactly. This behaviour can be modified using the inl_cpt_channel devargs parameter.

    For example:

    -a 0002:1d:00.0,inl_cpt_channel=0x100/0xf00

    With the above configuration, RTE Flow rules API will set the channel and channel mask as 0x100 and 0xF00 in the MCAM entries of the flow rules created with RTE_FLOW_ACTION_TYPE_SECURITY action. Since channel number is set with this custom mask, inbound encrypted traffic from all ports with matching channel number pattern will be directed to the inline IPSec device.

Note

Above devarg parameters are configurable per device, user needs to pass the parameters to all the PCIe devices if application requires to configure on all the ethdev ports.

12.5. Limitations

12.5.1. mempool_cnxk external mempool handler dependency

The OCTEON CN9K/CN10K SoC family NIC has inbuilt HW assisted external mempool manager. net_cnxk PMD only works with mempool_cnxk mempool handler as it is performance wise most effective way for packet allocation and Tx buffer recycling on OCTEON TX2 SoC platform.

12.5.2. CRC stripping

The OCTEON CN9K/CN10K SoC family NICs strip the CRC for every packet being received by the host interface irrespective of the offload configuration.

12.5.3. RTE flow GRE support

  • RTE_FLOW_ITEM_TYPE_GRE_KEY works only when checksum and routing bits in the GRE header are equal to 0.

12.5.4. RTE flow action port_id support

  • RTE_FLOW_ACTION_TYPE_PORT_ID is only supported between PF and its VFs.

12.5.5. Custom protocols supported in RTE Flow

The RTE_FLOW_ITEM_TYPE_RAW can be used to parse the below custom protocols.

  • vlan_exdsa and exdsa can be parsed at L2 level.

  • NGIO can be parsed at L3 level.

For vlan_exdsa and exdsa, the port has to be configured with the respective switch header.

For example:

-a 0002:02:00.0,switch_header="vlan_exdsa"

The below fields of struct rte_flow_item_raw shall be used to specify the pattern.

  • relative Selects the layer at which parsing is done.

    • 0 for exdsa and vlan_exdsa.

    • 1 for NGIO.

  • offset The offset in the header where the pattern should be matched.

  • length Length of the pattern.

  • pattern Pattern as a byte string.

Example usage in testpmd:

./dpdk-testpmd -c 3 -w 0002:02:00.0,switch_header=exdsa -- -i \
               --rx-offloads=0x00080000 --rxq 8 --txq 8
testpmd> flow create 0 ingress pattern eth / raw relative is 0 pattern \
       spec ab pattern mask ab offset is 4 / end actions queue index 1 / end

12.6. Inline device support for CN10K

CN10K HW provides a misc device Inline device that supports ethernet devices in providing following features.

  • Aggregate all the inline IPsec inbound traffic from all the CN10K ethernet devices to be processed by the single inline IPSec device. This allows single rte security session to accept traffic from multiple ports.

  • Support for event generation on outbound inline IPsec processing errors.

  • Support CN106xx poll mode of operation for inline IPSec inbound processing.

Inline IPsec device is identified by PCI PF vendid:devid 177D:A0F0 or VF 177D:A0F1.

12.6.1. Runtime Config Options for inline device

  • Max SPI for inbound inline IPsec (default 255)

    Max SPI supported for inbound inline IPsec processing can be specified by ipsec_in_max_spi devargs parameter.

    For example:

    -a 0002:1d:00.0,ipsec_in_max_spi=128

    With the above configuration, application can enable inline IPsec processing for 128 inbound SAs (SPI 0-127) for traffic aggregated on inline device.

12.7. Debugging Options

Table 12.98 cnxk ethdev debug options

#

Component

EAL log command

1

NIX

–log-level=’pmd.net.cnxk,8’

2

NPC

–log-level=’pmd.net.cnxk.flow,8’