Cut and Forward: Safe and Secure Communication for FPGA System on Chips

Modern FPGA system on chips uses complex multimanager, multisubordinate on-chip communication networks. Processor cores, hardware accelerators, DMA engines, and other manager components actively access subordinate components like off-chip DRAM, on-chip memories, caches, and I/Os. On-chip communication networks are designed for high bandwidth and low latency. They use simple, fast transactions that largely assumes the managers cooperate. For example, it does not describe default mechanisms to ensure the safe behaviors of the managers using the on-chip interconnect. This lack of specification can lead to unpredictable behaviors: a single misbehaving, misconfigured, or malicious component can cause denial of service of shared resources. Clearly, this issue is critical in systems with safety and security constraints. Cut and forward is a novel switching method for multicomponent communication architectures on FPGA systems on chips (SoCs). Cut and forward leverages the programmability of FPGA SoCs to enable safe and secure bus access and is carefully designed to minimize its impact on performance and resource usage. Experiments show that Cut and forward ensures safety and security in realistic applications deployed on a commercial FPGA SoC from Xilinx including a popular deep neural network accelerator.