The Soft NIC allows building custom NIC pipelines in software. The Soft NIC pipeline is DIY and reconfigurable through firmware (DPDK Packet Framework script).
The Soft NIC leverages the DPDK Packet Framework libraries (librte_port, librte_table and librte_pipeline) to make it modular, flexible and extensible with new functionality. Please refer to DPDK Programmer’s Guide, Chapter Packet Framework and DPDK Sample Application User Guide, Chapter IP Pipeline Application for more details.
The Soft NIC is configured through the standard DPDK ethdev API (ethdev, flow, QoS, security). The internal framework is not externally visible.
Any Linux distribution fulfilling the conditions described in System Requirements section of the DPDK documentation or refer to DPDK Release Notes.
The default PMD configuration available in the common_linuxapp configuration file:
CONFIG_RTE_LIBRTE_PMD_SOFTNIC=y
Once the DPDK is built, all the DPDK applications include support for the Soft NIC PMD.
The user can specify below arguments in EAL --vdev options to create the Soft NIC device instance:
–vdev “net_softnic0,firmware=firmware.cli,conn_port=8086”
Run testpmd application in Soft NIC forwarding mode with loopback feature enabled on Soft NIC port:
./testpmd -c 0x3 --vdev 'net_softnic0,firmware=<script path>/firmware.cli,cpu_id=0,conn_port=8086' -- -i --forward-mode=softnic --portmask=0x2... Interactive-mode selected Set softnic packet forwarding mode ... Configuring Port 0 (socket 0) Port 0: 90:E2:BA:37:9D:DC Configuring Port 1 (socket 0) ; SPDX-License-Identifier: BSD-3-Clause ; Copyright(c) 2018 Intel Corporation link LINK dev 0000:02:00.0 pipeline RX period 10 offset_port_id 0 pipeline RX port in bsz 32 link LINK rxq 0 pipeline RX port out bsz 32 swq RXQ0 pipeline RX table match stub pipeline RX port in 0 table 0 pipeline TX period 10 offset_port_id 0 pipeline TX port in bsz 32 swq TXQ0 pipeline TX port out bsz 32 link LINK txq 0 pipeline TX table match stub pipeline TX port in 0 table 0 thread 1 pipeline RX enable thread 1 pipeline TX enable Port 1: 00:00:00:00:00:00 Checking link statuses... Done testpmd>
Start forwarding
testpmd> start softnic packet forwarding - ports=1 - cores=1 - streams=1 - NUMA support enabled, MP over anonymous pages disabled Logical Core 1 (socket 0) forwards packets on 1 streams: RX P=2/Q=0 (socket 0) -> TX P=2/Q=0 (socket 0) peer=02:00:00:00:00:02 softnic 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=0x1000 Tx offloads=0x0 RX queue: 0 RX desc=512 - RX free threshold=32 RX threshold registers: pthresh=8 hthresh=8 wthresh=0 RX Offloads=0x0 TX queue: 0 TX desc=512 - TX free threshold=32 TX threshold registers: pthresh=32 hthresh=0 wthresh=0 TX offloads=0x0 - TX RS bit threshold=32 port 1: RX queue number: 1 Tx queue number: 1 Rx offloads=0x0 Tx offloads=0x0 RX queue: 0 RX desc=0 - RX free threshold=0 RX threshold registers: pthresh=0 hthresh=0 wthresh=0 RX Offloads=0x0 TX queue: 0 TX desc=0 - TX free threshold=0 TX threshold registers: pthresh=0 hthresh=0 wthresh=0 TX offloads=0x0 - TX RS bit threshold=0
Start remote client (e.g. telnet) to communicate with the softnic device:
$ telnet 127.0.0.1 8086 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. Welcome to Soft NIC! softnic>
Add/update Soft NIC pipeline table match-action entries from telnet client:
softnic> pipeline RX table 0 rule add match default action fwd port 0 softnic> pipeline TX table 0 rule add match default action fwd port 0
The Soft NIC firmware, for example- softnic/firmware.cli, consists of following CLI commands for creating and managing software based NIC pipelines. For more details, please refer to CLI command description provided in softnic/rte_eth_softnic_cli.c.
Physical port for packets send/receive:
link LINK dev 0000:02:00.0
Pipeline create:
pipeline RX period 10 offset_port_id 0 (Soft NIC rx-path pipeline) pipeline TX period 10 offset_port_id 0 (Soft NIC tx-path pipeline)
Pipeline input/output port create
pipeline RX port in bsz 32 link LINK rxq 0 (Soft NIC rx pipeline input port) pipeline RX port out bsz 32 swq RXQ0 (Soft NIC rx pipeline output port) pipeline TX port in bsz 32 swq TXQ0 (Soft NIC tx pipeline input port) pipeline TX port out bsz 32 link LINK txq 0 (Soft NIC tx pipeline output port)
Pipeline table create
pipeline RX table match stub (Soft NIC rx pipeline match-action table) pipeline TX table match stub (Soft NIC tx pipeline match-action table)
Pipeline input port connection with table
pipeline RX port in 0 table 0 (Soft NIC rx pipeline input port 0 connection with table 0) pipeline TX port in 0 table 0 (Soft NIC tx pipeline input port 0 connection with table 0)
Pipeline table match-action rules add
pipeline RX table 0 rule add match default action fwd port 0 (Soft NIC rx pipeline table 0 rule) pipeline TX table 0 rule add match default action fwd port 0 (Soft NIC tx pipeline table 0 rule)
Enable pipeline on CPU thread
thread 1 pipeline RX enable (Soft NIC rx pipeline enable on cpu thread id 1) thread 1 pipeline TX enable (Soft NIC tx pipeline enable on cpu thread id 1)
SoftNIC PMD implements ethdev traffic management APIs rte_tm.h that allow building and committing traffic manager hierarchy, configuring hierarchy nodes of the Quality of Service (QoS) scheduler supported by DPDK librte_sched library. Furthermore, APIs for run-time update to the traffic manager hierarchy are supported by PMD.
SoftNIC PMD also implements ethdev traffic metering and policing APIs rte_mtr.h that enables metering and marking of the packets with the appropriate color (green, yellow or red), according to the traffic metering algorithm. For the meter output color, policer actions like keep the packet color same, change the packet color or drop the packet can be configured.
Note
The SoftNIC does not support the meter object shared by several flows, thus only supports creating meter object private to the flow. Once meter object is successfully created, it can be linked to the specific flow by specifying the meter flow action in the flow rule.
The SoftNIC PMD implements ethdev flow APIs rte_flow.h that allow validating flow rules, adding flow rules to the SoftNIC pipeline as table rules, deleting and querying the flow rules. The PMD provides new cli command for creating the flow group and their mapping to the SoftNIC pipeline and table. This cli should be configured as part of firmware file.
flowapi map group <group_id> ingress | egress pipeline <pipeline_name> \ table <table_id>
From the flow attributes of the flow, PMD uses the group id to get the mapped pipeline and table. PMD supports number of flow actions such as JMP, QUEUE, RSS, DROP, COUNT, METER, VXLAN etc.
Note
The flow must have one terminating actions i.e. JMP or RSS or QUEUE or DROP. For the count and drop actions the underlying PMD doesn’t support the functionality yet. So it is not recommended for use.
The flow API can be tested with the help of testpmd application. The SoftNIC firmware specifies CLI commands for port configuration, pipeline creation, action profile creation and table creation. Once application gets initialized, the flow rules can be added through the testpmd CLI. The PMD will translate the flow rules to the SoftNIC pipeline tables rules.
Example demonstrates the flow queue action using the SoftNIC firmware and testpmd commands.
Prepare SoftNIC firmware
link LINK0 dev 0000:83:00.0 link LINK1 dev 0000:81:00.0 pipeline RX period 10 offset_port_id 0 pipeline RX port in bsz 32 link LINK0 rxq 0 pipeline RX port in bsz 32 link LINK1 rxq 0 pipeline RX port out bsz 32 swq RXQ0 pipeline RX port out bsz 32 swq RXQ1 table action profile AP0 ipv4 offset 278 fwd pipeline RX table match hash ext key 16 mask 00FF0000FFFFFFFFFFFFFFFFFFFFFFFF \ offset 278 buckets 16K size 65K action AP0 pipeline RX port in 0 table 0 pipeline RX port in 1 table 0 flowapi map group 0 ingress pipeline RX table 0 pipeline TX period 10 offset_port_id 0 pipeline TX port in bsz 32 swq TXQ0 pipeline TX port in bsz 32 swq TXQ1 pipeline TX port out bsz 32 link LINK0 txq 0 pipeline TX port out bsz 32 link LINK1 txq 0 pipeline TX table match hash ext key 16 mask 00FF0000FFFFFFFFFFFFFFFFFFFFFFFF \ offset 278 buckets 16K size 65K action AP0 pipeline TX port in 0 table 0 pipeline TX port in 1 table 0 pipeline TX table 0 rule add match hash ipv4_5tuple 1.10.11.12 2.20.21.22 100 200 6 action fwd port 0 pipeline TX table 0 rule add match hash ipv4_5tuple 1.10.11.13 2.20.21.23 100 200 6 action fwd port 1 thread 25 pipeline RX enable thread 25 pipeline TX enable
Run testpmd:
./x86_64-native-linuxapp-gcc/app/testpmd -l 23-25 -n 4 \ --vdev 'net_softnic0, \ firmware=./drivers/net/softnic/ \ firmware.cli, \ cpu_id=1,conn_port=8086' -- \ -i --forward-mode=softnic --rxq=2, \ --txq=2, --disable-rss --portmask=0x4
Configure flow rules on softnic:
flow create 2 group 0 ingress pattern eth / ipv4 proto mask 255 src \ mask 255.255.255.255 dst mask 255.255.255.255 src spec 1.10.11.12 dst spec 2.20.21.22 proto spec 6 / tcp src mask 65535 \ dst mask 65535 src spec 100 dst spec 200 / end actions queue \ index 0 / end flow create 2 group 0 ingress pattern eth / ipv4 proto mask 255 src \ mask 255.255.255.255 dst mask 255.255.255.255 src spec 1.10.11.13 \ dst spec 2.20.21.23 proto spec 6 / tcp src mask 65535 dst mask \ 65535 src spec 100 dst spec 200 / end actions queue index 1 / end