AXI HyperConnect: A Predictable, Hypervisor-level Interconnect for Hardware Accelerators in FPGA SoC

FPGA-based system-on-chips (SoC) are powerful computing platforms to implement mixed-criticality systems that require both multiprocessing and hardware acceleration. Virtualization via hypervisor technologies is, de-facto, an effective technique to allow the co-existence of multiple execution domains with different criticality levels in isolation upon the same platform. Implementing such technologies on FPGA-based SoC poses new challenges: one of such is the isolation of hardware accelerators deployed on the FPGA fabric that belong to different domains but share common resources such as a memory bus. This paper proposes AXI HyperConnect, a hypervisor-level hardware component that allows interconnecting hardware accelerators to the same bus while ensuring isolation and predictability features. AXI HyperConnect has been implemented on modern FPGA-SoC by Xilinx and tested with real-world accelerators, including one for Deep Neural Network inference.