GTS AXI Multichannel DMA IP for PCI Express* User Guide

ID 847470
Date 8/25/2025
Public
Document Table of Contents

6.3.6.3.1. Device-side Packet Loopback

The DPDK driver can also be used with the AXI-S Device-side Packet Loopback design example for loopback test.

The following diagram shows the testing strategy.

Complete the instructions outlined in Prerequisites before running the following command for the loopback test:
$ cd dpdk-stable/build/examples/mcdma-test/perfq
$ sudo ./build/mcdma-test -m 8192 --file-prefix=pf0 -l 0-15 -- -b 0000:98:00.0 
-p 32768 -d 2 -c 1 -a 2 -l 5 -i
Configuration:
  • Memory allocation size (-m 8192)
  • Physical function number (--file-prefix=pf0)
  • Number of CPU cores allocated for the test (-l 0-15), to match the output from the "sudo lscpu | grep NUMA" command
  • BDF (-b 0000:01:00.0)
  • 1 DMA channel (-c 1)
  • Bidirectional H2D-D2H Loopback (-i)
  • Payload length of 32,768 bytes in each descriptor (-p 32768)
  • Transfer the data for 5 seconds (-l 5)
  • Dump the progress log every 2 seconds (-d 2)
  • Total of two threads (-a 2)
  • Transfer data for 5 seconds (-l 5)