8. I40E Poll Mode Driver

The I40E PMD (librte_pmd_i40e) provides poll mode driver support for the Intel X710/XL710/X722 10/40 Gbps family of adapters.

8.1. Features

Features of the I40E PMD are:

Multiple queues for TX and RX
Receiver Side Scaling (RSS)
MAC/VLAN filtering
Packet type information
Flow director
Cloud filter
Checksum offload
VLAN/QinQ stripping and inserting
TSO offload
Promiscuous mode
Multicast mode
Port hardware statistics
Jumbo frames
Link state information
Link flow control
Mirror on port, VLAN and VSI
Interrupt mode for RX
Scattered and gather for TX and RX
Vector Poll mode driver
DCB
VMDQ
SR-IOV VF
Hot plug
IEEE1588/802.1AS timestamping

8.2. Prerequisites

Identifying your adapter using Intel Support and get the latest NVM/FW images.
Follow the DPDK Getting Started Guide for Linux to setup the basic DPDK environment.
To get better performance on Intel platforms, please follow the “How to get best performance with NICs on Intel platforms” section of the Getting Started Guide for Linux.

8.3. Pre-Installation Configuration

8.3.1. 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_I40E_PMD (default y)

Toggle compilation of the librte_pmd_i40e driver.
CONFIG_RTE_LIBRTE_I40E_DEBUG_* (default n)

Toggle display of generic debugging messages.
CONFIG_RTE_LIBRTE_I40E_RX_ALLOW_BULK_ALLOC (default y)

Toggle bulk allocation for RX.
CONFIG_RTE_LIBRTE_I40E_INC_VECTOR (default n)

Toggle the use of Vector PMD instead of normal RX/TX path. To enable vPMD for RX, bulk allocation for Rx must be allowed.
CONFIG_RTE_LIBRTE_I40E_RX_OLFLAGS_ENABLE (default y)

Toggle to enable RX olflags. This is only meaningful when Vector PMD is used.
CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC (default n)

Toggle to use a 16-byte RX descriptor, by default the RX descriptor is 32 byte.
CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_PF (default 64)

Number of queues reserved for PF.
CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_VF (default 4)

Number of queues reserved for each SR-IOV VF.
CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_VM (default 4)

Number of queues reserved for each VMDQ Pool.
CONFIG_RTE_LIBRTE_I40E_ITR_INTERVAL (default -1)

Interrupt Throttling interval.

8.3.2. Driver Compilation

To compile the I40E PMD see Getting Started Guide for Linux or Getting Started Guide for FreeBSD depending on your platform.

8.4. Linux

8.4.1. Running testpmd

This section demonstrates how to launch testpmd with Intel XL710/X710 devices managed by librte_pmd_i40e in the Linux operating system.

Load igb_uio or vfio-pci driver:

modprobe uio
insmod ./x86_64-native-linuxapp-gcc/kmod/igb_uio.ko

or

modprobe vfio-pci

Bind the XL710/X710 adapters to igb_uio or vfio-pci loaded in the previous step:
```
./tools/dpdk_nic_bind.py --bind igb_uio 0000:83:00.0
```
Or setup VFIO permissions for regular users and then bind to vfio-pci:
```
./tools/dpdk_nic_bind.py --bind vfio-pci 0000:83:00.0
```

Start testpmd with basic parameters:

./x86_64-native-linuxapp-gcc/app/testpmd -c 0xf -n 4 -w 83:00.0 -- -i

Example output:

...
EAL: PCI device 0000:83:00.0 on NUMA socket 1
EAL: probe driver: 8086:1572 rte_i40e_pmd
EAL: PCI memory mapped at 0x7f7f80000000
EAL: PCI memory mapped at 0x7f7f80800000
PMD: eth_i40e_dev_init(): FW 5.0 API 1.5 NVM 05.00.02 eetrack 8000208a
Interactive-mode selected
Configuring Port 0 (socket 0)
...

PMD: i40e_dev_rx_queue_setup(): Rx Burst Bulk Alloc Preconditions are
satisfied.Rx Burst Bulk Alloc function will be used on port=0, queue=0.

...
Port 0: 68:05:CA:26:85:84
Checking link statuses...
Port 0 Link Up - speed 10000 Mbps - full-duplex
Done

testpmd>

8.4.2. SR-IOV: Prerequisites and sample Application Notes

Load the kernel module:

modprobe i40e

Check the output in dmesg:

i40e 0000:83:00.1 ens802f0: renamed from eth0

Bring up the PF ports:
```
ifconfig ens802f0 up
```
Create VF device(s):

Echo the number of VFs to be created into the sriov_numvfs sysfs entry of the parent PF.

Example:
```
echo 2 > /sys/devices/pci0000:00/0000:00:03.0/0000:81:00.0/sriov_numvfs
```

Assign VF MAC address:

Assign MAC address to the VF using iproute2 utility. The syntax is:

ip link set <PF netdev id> vf <VF id> mac <macaddr>

Example:

ip link set ens802f0 vf 0 mac a0:b0:c0:d0:e0:f0

Assign VF to VM, and bring up the VM. Please see the documentation for the I40E/IXGBE/IGB Virtual Function Driver.

8.5. Sample Application Notes

8.5.1. Vlan filter

Vlan filter only works when Promiscuous mode is off.

To start testpmd, and add vlan 10 to port 0:

./app/testpmd -c ffff -n 4 -- -i --forward-mode=mac
...

testpmd> set promisc 0 off
testpmd> rx_vlan add 10 0

8.5.2. Flow Director

The Flow Director works in receive mode to identify specific flows or sets of flows and route them to specific queues. The Flow Director filters can match the different fields for different type of packet: flow type, specific input set per flow type and the flexible payload.

The default input set of each flow type is:

ipv4-other : src_ip_address, dst_ip_address
ipv4-frag  : src_ip_address, dst_ip_address
ipv4-tcp   : src_ip_address, dst_ip_address, src_port, dst_port
ipv4-udp   : src_ip_address, dst_ip_address, src_port, dst_port
ipv4-sctp  : src_ip_address, dst_ip_address, src_port, dst_port,
             verification_tag
ipv6-other : src_ip_address, dst_ip_address
ipv6-frag  : src_ip_address, dst_ip_address
ipv6-tcp   : src_ip_address, dst_ip_address, src_port, dst_port
ipv6-udp   : src_ip_address, dst_ip_address, src_port, dst_port
ipv6-sctp  : src_ip_address, dst_ip_address, src_port, dst_port,
             verification_tag
l2_payload : ether_type

The flex payload is selected from offset 0 to 15 of packet’s payload by default, while it is masked out from matching.

Start testpmd with --disable-rss and --pkt-filter-mode=perfect:

./app/testpmd -c ffff -n 4 -- -i --disable-rss --pkt-filter-mode=perfect \
              --rxq=8 --txq=8 --nb-cores=8 --nb-ports=1

Add a rule to direct ipv4-udp packet whose dst_ip=2.2.2.5, src_ip=2.2.2.3, src_port=32, dst_port=32 to queue 1:

testpmd> flow_director_filter 0 mode IP add flow ipv4-udp  \
         src 2.2.2.3 32 dst 2.2.2.5 32 vlan 0 flexbytes () \
         fwd pf queue 1 fd_id 1

Check the flow director status:

testpmd> show port fdir 0

######################## FDIR infos for port 0      ####################
  MODE:   PERFECT
  SUPPORTED FLOW TYPE:  ipv4-frag ipv4-tcp ipv4-udp ipv4-sctp ipv4-other
                        ipv6-frag ipv6-tcp ipv6-udp ipv6-sctp ipv6-other
                        l2_payload
  FLEX PAYLOAD INFO:
  max_len:       16          payload_limit: 480
  payload_unit:  2           payload_seg:   3
  bitmask_unit:  2           bitmask_num:   2
  MASK:
    vlan_tci: 0x0000,
    src_ipv4: 0x00000000,
    dst_ipv4: 0x00000000,
    src_port: 0x0000,
    dst_port: 0x0000
    src_ipv6: 0x00000000,0x00000000,0x00000000,0x00000000,
    dst_ipv6: 0x00000000,0x00000000,0x00000000,0x00000000
  FLEX PAYLOAD SRC OFFSET:
    L2_PAYLOAD:    0      1      2      3      4      5      6  ...
    L3_PAYLOAD:    0      1      2      3      4      5      6  ...
    L4_PAYLOAD:    0      1      2      3      4      5      6  ...
  FLEX MASK CFG:
    ipv4-udp:    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ipv4-tcp:    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ipv4-sctp:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ipv4-other:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ipv4-frag:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ipv6-udp:    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ipv6-tcp:    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ipv6-sctp:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ipv6-other:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ipv6-frag:   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    l2_payload:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  guarant_count: 1           best_count:    0
  guarant_space: 512         best_space:    7168
  collision:     0           free:          0
  maxhash:       0           maxlen:        0
  add:           0           remove:        0
  f_add:         0           f_remove:      0

Delete all flow director rules on a port:

testpmd> flush_flow_director 0