Lightweight multicore virtualization architecture exploiting ARM TrustZone

Virtualization technology is well established in the server and desktop spaces, and has been spreading across embedded system market. This technology allows for the coexistence and execution of multiples operating systems on top of the same hardware platform, with proven technological and economic benefits. Hardware extensions for easing virtualization have been added into several commercial off-the-shelf processors. Among existing technologies, ARM TrustZone is gaining particular attention due to its broadly availability into ARM processors. However, existent TrustZone-assisted virtualization solutions are limited to a dual-guest and single-core configuration, which can lead to the starvation of the non-secure side when the secure world does not yield the processor. This work presents the extension of a TrustZone-assisted hypervisor to an asymmetric multi-processing configuration. We describe and demonstrate how to run a general-purpose operating system side-by-side with an real-time operating system in a Xilinx Zynq-based platform, enhanced with a dual ARM Cortex-A9. The achieved results demonstrate that the implemented multicore approach not only completely eliminates starvation, but also increases the general-purpose operating system's performance, especially when the real-time workload is demanding.