P4-To-VHDL: Automatic generation of high-speed input and output network blocks

High-performance embedded architectures typically contain many stand-alone blocks which communicate and exchange data; additionally a high-speed network interface is usually needed at the boundary of the system. The software-based data processing is typically slow which leads to a need for hardware accelerated approaches. The problem is getting harder if the supported protocol stack is rapidly changing. Such problem can be effectively solved by the Field Programmable Gate Arrays and high-level synthesis which together provide a high degree of generality. This approach has several advantages like fast development or possibility to enable the area of packet-oriented communication to domain oriented experts. However, the typical disadvantage of this approach is the insufficient performance of generated system from a high-level description. This can be a serious problem in the case of a system which is required to process data at high packet rates. This work presents a generator of high-speed input (Parser) and output (Deparser) network blocks from the P4 language which is designed for the description of modern packet processing devices. The tool converts a P4 description to a synthesizable VHDL code suitable for the FPGA implementation. We present design, analysis and experimental results of our generator. Our results show that the generated circuits are able to process 100 Gbps traffic with fairly complex protocol structure at line rate on Xilinx Virtex-7 XCVH580T FPGA. The approach can be used not only in networking devices but also in other applications like packet processing engines in embedded cores because the P4 language is device and protocol independent.