Simple Forward VNF

NVIDIA DOCA Simple Forward VNF Application Guide

This document provides a Simple Forward implementation on top of NVIDIA® BlueField® DPU.

1. Introdution

Simple forward is a forwarding application that takes either VXLAN, GRE, or GTP traffic from a single RX port and transmits it on a single TX port.

For every packet received on an RX queue on a given port, DOCA Simple Forward checks the packet's key, which consists of a 5-tuple. If it finds that the packet matches an existing flow, then it does not create a new one. Otherwise, a new flow is created with a FORWARDING component. Finally, the packet is forwarded to the TX queue of the egress port. Refer to Arg Parser DOCA Flags if "rx-only" mode is not set.

The FORWARDING component type depends on the flags delivered when running the application. For example, if the hairpinq flag is provided, then the FORWARDING component would be hairpin. Otherwise, it would be RSS'd to software, and hence every VXLAN, GTP, or GRE packet would be received on RX queues.

Simple forward should be run with dual ports. By using a traffic generator, the RX port receives the VXLAN, GRE, or GTP packets and forwarding forwards them back to the traffic generator.

2. System Design

The following diagram illustrates simple forward's packet flows. It receives traffic coming from the wire and passes it to the other port.

3. Application Architecture

Simple forward first initializes DPDK, after which the application handles the incoming packets.

The following diagram illustrates the initialization process.

Init_DPDK – EAL init, parse argument from command line and register signal.
Start port – mbuf_create, dev_configure, rx/tx/hairpin queue setup and start the port.
Simple_fwd INIT – create flow tables, build default forward pipes.

The following diagram illustrates how to process the packet.

Based on the packet's info, find the key values (e.g. src/dst IP, src/dst port, etc).
Traverse the inner flow tables, check if the keys exist or not.
- If yes, update inner counter
- If no, a new flow table is added and new pipes are configured on the DPU
Forward the packet to the other port.

4. DOCA Libraries

This application leverages the DOCA Flow Library.

5. Configuration Flow

Parse application argument.

Copy
Copied!

            
            doca_argp_init();

Initialize arg parser resources.

Register DOCA general flags.

Copy
Copied!

            
            register_simple_fwd_params();

Register application flags.

Copy
Copied!

            
            doca_argp_start();

Parse DPDK flags and invoke handler for calling the rte_eal_init() function.
Parse app flags.

DPDK initialization.
Copy

Copied!
```
            
            dpdk_init();
        
```
Calls rte_eal_init() to initialize EAL resources with the provided EAL flags.
DPDK port initialization and start.
Copy

Copied!
```
            
            dpdk_queues_and_ports_init();
        
```
1. Initialize DPDK ports.
2. Create mbuf pool using rte_pktmbuf_pool_create
3. Driver initialization – use rte_eth_dev_configure to configure the number of queues
4. Rx/Tx queue initialization – use rte_eth_rx_queue_setup and rte_eth_tx_queue_setup to initialize the queues
5. Rx hairpin queue initialization – use rte_eth_rx_hairpin_queue_setup to initialize the queues
6. Start the port using rte_eth_dev_start
Simple forward initialization.
Copy

Copied!
```
            
            simple_fwd_init();
        
```
1. simple_fwd_create_ins - create flow tables using simple_fwd_ft_create
2. simple_fwd_init_ports_and_pipes – initialize DOCA port using simple_fwd_init_doca_port and build default pipes for each port.
Main loop.
Copy

Copied!
```
            
            simple_fwd_process_pkts();
        
```
1. Receive packets using rte_eth_rx_burst in a loop
2. Process packets using simple_fwd_process_offload
3. Transmit the packets on the other port by calling rte_eth_tx_burst. Or free the packet mbuf if rx_only is set to true.
Process packets.
Copy

Copied!
```
            
            simple_fwd_process_offload();
        
```
1. Parse the packet's rte_mbuf using simple_fwd_pkt_info.
2. Handle the packet using simple_fwd_handle_packet. If the packet's key does not match the existed the flow entry, create a new flow entry and PIPE using simple_fwd_handle_new_flow. Otherwise, increase the total packet's counter.
Simple forward destroy.
Copy

Copied!
```
            
            simple_fwd_destroy();
        
```
Simple forward closes port and cleans the flow resources.

DPDK ports and queues destruction.

Copy
Copied!

            
            dpdk_queues_and_ports_fini();

DPDK finish.
Copy

Copied!
```
            
            dpdk_fini();
        
```
Calls rte_eal_destroy() to destroy initialized EAL resources.

Arg parser destroy.

Copy
Copied!

            
            doca_argp_destroy();

Free DPDK resources by call rte_eal_cleanup() function.

6. Running Application

Refer to the following documents:
- NVIDIA DOCA Installation Guide for details on how to install BlueField-related software.
- NVIDIA DOCA Troubleshooting Guide for any issue you may encounter with the installation, compilation, or execution of DOCA applications.
The simple forward binary is located under /opt/mellanox/doca/applications/simple_fwd_vnf/bin/doca_simple_fwd_vnf. To build all the applications together, run:
Copy

Copied!
```
            
            cd /opt/mellanox/doca/applications/
meson build 
ninja -C build
        
```

To build the simple forward sample only:

Edit the following flags in /opt/mellanox/doca/applications/meson_option.txt:
- Set enable_all_applications to false
- Set enable_simple_fwd_vnf to true
Run the commands in step 2.

Note:

doca_simple_fwd_vnf is created under ./build/simple_fwd_vnf/src/.

Application usage:

Copy
Copied!

            
            Usage: doca_simple_forward_vnf [DPDK Flags] -- [DOCA Flags] [Program Flags]
DOCA Flags:
  -h, --help                    Print a help synopsis
  -v, --version                 Print program version information
  -l, --log-level               Set the log level for the app <CRITICAL=0, DEBUG=4>
Program Flags:
  -t, --stats-timer <time>      Set interval to dump stats information
  -q, --nr-queues <num>         Set queues number
  -r, --rx-only                 Set rx only
  -o, --hw-offload              Set hw offload
  -hq, --hairpinq               Set forwarding to hairpin queue
  -a, --age-thread              Start thread do aging

Note:

For additional information on available flags for EAL, use -h before the -- separator:

Copy
Copied!

            
            /opt/mellanox/doca/applications/simple_fwd_vnf/bin/doca_simple_fwd_vnf -h

Note:

For additional information on the application, use -h after the -- separator:

Copy
Copied!

            
            /opt/mellanox/doca/applications/simple_fwd_vnf/bin/doca_simple_fwd_vnf -- -h

Running the application on BlueField:

Pre-run setup: The simple forward example is based on DPDK libraries. Therefore, the user is required to provide DPDK flags, and allocate huge pages.
Copy

Copied!
```
            
            sudo echo 2048 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
        
```

CLI example for running the app:

Copy
Copied!

            
            /opt/mellanox/doca/applications/simple_fwd_vnf/bin/doca_simple_fwd_vnf -a auxiliary:mlx5_core.sf.4 -a auxiliary:mlx5_core.sf.5 -- -l 4

Note:

The flag -a auxiliary:mlx5_core.sf.4 -a auxiliary:mlx5_core.sf.5 is mandatory for proper usage of the application. Modifying this flag results unexpected behavior as only 2 ports are supported. The SF number is arbitrary and configurable.

Note:

SFs must be enabled according to Scalable Function Setup Guide. Before creating SFs on a specific physical port, it is important to verify the encap mode on the respective PF FDB. The default mode is basic. To check the encap mode, run:

Copy
Copied!

            
            cat /sys/class/net/p0/compat/devlink/encap

In this case, disable encap on the PF FDB before creating the SFs by running:

Copy
Copied!

            
            /opt/mellanox/iproute2/sbin/devlink dev eswitch set pci/0000:03:00.0 mode legacy
/opt/mellanox/iproute2/sbin/devlink dev eswitch set pci/0000:03:00.1 mode legacy
echo none > /sys/class/net/p0/compat/devlink/encap
echo none > /sys/class/net/p1/compat/devlink/encap
/opt/mellanox/iproute2/sbin/devlink dev eswitch set pci/0000:03:00.0 mode switchdev
/opt/mellanox/iproute2/sbin/devlink dev eswitch set pci/0000:03:00.1 mode switchdev

Note that if the encap mode is set to basic then the application fails upon initialization.

Running the application on the host, CLI example:

Copy
Copied!

            
            /opt/mellanox/doca/applications/simple_fwd_vnf/bin/doca_simple_fwd_vnf -a 04:00.3 -a 04:00.4 -- -l 4

Note:

Refer to section "Running DOCA Application on Host" in NVIDIA DOCA Virtual Functions User Guide.

To run doca_simple_fwd_vnf using a JSON file:

Copy
Copied!

            
            doca_simple_fwd_vnf --json [json_file]

For example:

Copy
Copied!

            
            cd /opt/mellanox/doca/applications/simple_fwd_vnf/bin
./doca_simple_fwd_vnf --json simple_fwd_params.json

7. Arg Parser DOCA Flags

Refer to NVIDIA DOCA Arg Parser User Guide for more information.

Flag Type	Short Flag	Long Flag/JSON Key	Description	JSON Content
DPDK Flags	a	devices	Add a PCIe device into the list of devices to probe.	Copy Copied! `"devices": [ {"device": "sf", "id": “4”,"sft": true}, {"device": "sf", "id": “5”,"sft": true}, ]`
General Flags	l	log-level	Set the log level for the application: CRITICAL=0 ERROR=1 WARNING=2 INFO=3 DEBUG=4	Copy Copied! `"log-level": 4`
	v	version	Print program version information.	N/A
	h	help	Print a help synopsis.	N/A
Program Flags	t	stats-timer	Set interval to dump stats information.	Copy Copied! `"stats-timer": 2`
	q	nr-queues	Set queues number.	Copy Copied! `"nr-queues": 4`
	r	rx-only	Set RX only. When set, the packets will not be sent to the TX queues.	Copy Copied! `"rx-only": false`
	o	hw-offload	Set HW offload of the RXP engine to use.	Copy Copied! `"hw-offload": false`
	hq	hairpinq	Set forwarding to hairpin queue.	Copy Copied! `"hairpinq": false`
	a	age-thread	Start a dedicated thread that handles the aged flows.	Copy Copied! `"age-thread": false`

8. References

/opt/mellanox/doca/applications/simple_fwd_vnf/src/simple_fwd_vnf.c

Notices

Notice

This document is provided for information purposes only and shall not be regarded as a warranty of a certain functionality, condition, or quality of a product. NVIDIA Corporation nor any of its direct or indirect subsidiaries and affiliates (collectively: “NVIDIA”) make no representations or warranties, expressed or implied, as to the accuracy or completeness of the information contained in this document and assume no responsibility for any errors contained herein. NVIDIA shall have no liability for the consequences or use of such information or for any infringement of patents or other rights of third parties that may result from its use. This document is not a commitment to develop, release, or deliver any Material (defined below), code, or functionality.

NVIDIA reserves the right to make corrections, modifications, enhancements, improvements, and any other changes to this document, at any time without notice.

Customer should obtain the latest relevant information before placing orders and should verify that such information is current and complete.

NVIDIA products are sold subject to the NVIDIA standard terms and conditions of sale supplied at the time of order acknowledgement, unless otherwise agreed in an individual sales agreement signed by authorized representatives of NVIDIA and customer (“Terms of Sale”). NVIDIA hereby expressly objects to applying any customer general terms and conditions with regards to the purchase of the NVIDIA product referenced in this document. No contractual obligations are formed either directly or indirectly by this document.

NVIDIA products are not designed, authorized, or warranted to be suitable for use in medical, military, aircraft, space, or life support equipment, nor in applications where failure or malfunction of the NVIDIA product can reasonably be expected to result in personal injury, death, or property or environmental damage. NVIDIA accepts no liability for inclusion and/or use of NVIDIA products in such equipment or applications and therefore such inclusion and/or use is at customer’s own risk.

NVIDIA makes no representation or warranty that products based on this document will be suitable for any specified use. Testing of all parameters of each product is not necessarily performed by NVIDIA. It is customer’s sole responsibility to evaluate and determine the applicability of any information contained in this document, ensure the product is suitable and fit for the application planned by customer, and perform the necessary testing for the application in order to avoid a default of the application or the product. Weaknesses in customer’s product designs may affect the quality and reliability of the NVIDIA product and may result in additional or different conditions and/or requirements beyond those contained in this document. NVIDIA accepts no liability related to any default, damage, costs, or problem which may be based on or attributable to: (i) the use of the NVIDIA product in any manner that is contrary to this document or (ii) customer product designs.

No license, either expressed or implied, is granted under any NVIDIA patent right, copyright, or other NVIDIA intellectual property right under this document. Information published by NVIDIA regarding third-party products or services does not constitute a license from NVIDIA to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property rights of the third party, or a license from NVIDIA under the patents or other intellectual property rights of NVIDIA.

Reproduction of information in this document is permissible only if approved in advance by NVIDIA in writing, reproduced without alteration and in full compliance with all applicable export laws and regulations, and accompanied by all associated conditions, limitations, and notices.

THIS DOCUMENT AND ALL NVIDIA DESIGN SPECIFICATIONS, REFERENCE BOARDS, FILES, DRAWINGS, DIAGNOSTICS, LISTS, AND OTHER DOCUMENTS (TOGETHER AND SEPARATELY, “MATERIALS”) ARE BEING PROVIDED “AS IS.” NVIDIA MAKES NO WARRANTIES, EXPRESSED, IMPLIED, STATUTORY, OR OTHERWISE WITH RESPECT TO THE MATERIALS, AND EXPRESSLY DISCLAIMS ALL IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE. TO THE EXTENT NOT PROHIBITED BY LAW, IN NO EVENT WILL NVIDIA BE LIABLE FOR ANY DAMAGES, INCLUDING WITHOUT LIMITATION ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF ANY USE OF THIS DOCUMENT, EVEN IF NVIDIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Notwithstanding any damages that customer might incur for any reason whatsoever, NVIDIA’s aggregate and cumulative liability towards customer for the products described herein shall be limited in accordance with the Terms of Sale for the product.

Trademarks

NVIDIA, the NVIDIA logo, and Mellanox are trademarks and/or registered trademarks of Mellanox Technologies Ltd. and/or NVIDIA Corporation in the U.S. and in other countries. The registered trademark Linux® is used pursuant to a sublicense from the Linux Foundation, the exclusive licensee of Linus Torvalds, owner of the mark on a world¬wide basis. Other company and product names may be trademarks of the respective companies with which they are associated.

Notice

Trademarks

Copyright