lcf2016/vitis_roce

100 Gbps TCP/IP stack for Vitis shells

Vitis with 100 Gbps RoCE v2 Network Stack

This repository provides RoCE v2 network support at 100 Gbps in Vitis. Simple benchmark examples are provided to demonstrate the usage.

We use the Vitis_with_100Gbps_TCP-IP as our starting point. This project should fully compatable with the TCP/IP stack. The folder fpga-network-stack/ is replaced by submodule fpga-netwrok-stack, which is forked from the original one by ETHz systems group.

Architecture Overview

The same architecture as the TCP/IP project is used with three Vitis kernels: CMAC kernel, RoCE kernel and User kernel. Several User kernels are provided

The top level structure can be seen here.

CMAC kernel

The CMAC kernel remains the same as in Vitis_with_100Gbps_TCP-IP.

RoCE Kernel

Since we applied the RoCE as the networking stack, the network kenrel is repalced by our RoCE kernel. It includes serveral HLS IPs from fpga-netwrok-stack. This kernel works in the sequential mode and at 250 MHz. The interface can be found in the img/ directory.

More detials are comming in the future...

User Kernel

The User kernel is the kernel where user-defined applications are. It is the upper stream kernel that issues RDMA commands to the RoCE kernel. It can be designed for any application that needs RDMA networking. The required interface of the User kernel is shown here. This kernel also works in sequential execution mode as it should be triggered by the host program. It is clocked at 250 MHz in order to coordinate with the RoCE kernel.

Performance Benchmark

We did simple RDMA READ operation benchmarks to evaluate this RoCE stack. The throughput and latency results can be seen in the img/ folder.

Clone the Repository

Git Clone

git clone	
git submodule update --init --recursive

Package HLS IPs for the Stack

Setup the network stack HLS IPs:

mkdir build
cd build
cmake .. -DFDEV_NAME=u280
make installip

Create Design

The following example command will synthesis and implement the design with selected User kernel. The generated XCLBIN resides in folder build_dir.hw.xilinx_*. The generated host executable resides in folder host.

cd ../
make all DEVICE=/opt/xilinx/platforms/xilinx_u280_xdma_201920_3/xilinx_u280_xdma_201920_3.xpfm USER_KRNL=roce_read_krnl EXE_NUM=0

Explaination for the arguments are as follows. Default values can be found in Makefile.

• DEVICE Alveo development target platform
• TARGET Build targets defined by Vitis
• USER_KRNL Name of the user kernel
• NET_KRNL Either roce or tcp
• USER_KRNL_MODE If the user kernel is a rtl kernel, rtl mode should be specified. If the user kernel is a C/C++ kernel, then hls mode should be specified.
• EXE_NUM Either 0 or 1. Parameters required to establish an RDMA connection for two endpoints are set in 2 different host codes.
• IPREPOPATH The location of your packaged IPs

onnection established with that port. Usage: ./host XCLBIN_FILE [#RxByte] [Port] |

Repository structure

├── fpga-network-stack
├── scripts
├── kernel
│   └── cmac_krnl
│   └── network_krnl
│   └── rocetest_krnl
│   └── user_krnl
|		└── iperf_krnl
|		└── scatter_krnl
|		└── hls_send_krnl
|		└── hls_recv_krnl
|		└── roce_read_krnl
|		└── roce_write_krnl
|		└── hls_dummy_krnl
├── host
|	└── iperf_krnl
|	└── scatter_krnl
|	└── hls_send_krnl
|	└── hls_recv_krnl
|	└── roce_read_krnl
|	└── roce_write_krnl
|	└── hls_dummy_krnl
├── common
├── img

• fpga-network-stack: this folder contains the HLS code for 100 Gbps TCP/IP stack
• scripts: this folder contains scripts to pack each kernel and to connect cmac kernel with GT pins
• kernel: this folder contains the rtl/hls code of cmac kernel, network kernel and user kernel. User kernel can be configured to one of the example kernels
• host: this folder contains the host code of each user kernel
• img: this folder contains images
• common: this folder contains neccessary libraries for running the vitis kernel

Support

Tools

To package HLS IPs, use 2020.1.

Vitis	XRT
2020.2	2.9.317

Alveo Cards

Alveo	Development Target Platform(s)
U280	xilinx_u280_xdma_201920_3
U250	xilinx_u250_gen3x16_xdma_202020_1

We use the HBM on U280 and host memory on U250 as the memory block for RDMA. To switch to another FPGA, the configurations should be modified manully. For example, change the HBM[0] to HOST[0] here for the read kernel.

Requirements

In order to generate this design you will need a valid UltraScale+ Integrated 100G Ethernet Subsystem license set up in Vivado.

Acknowledgement

I would like to thank

• David Sidler for developing the InfiniBand RC transport service and RoCE v2 IPs in HLS
• Zhenhao He for the TCP/IP stack design and his help
• Mario Daniel Ruiz Noguera for sharing his knowledge on Xilinx FPGAs and Vitis tool
• Xilinx for providing the Xilinx Adaptive Compute Cluster
• Zaid Al-Ars for offering me this challenging project and guiding me through the journey