TZ- VirtIO: Enabling Standardized Inter-Partition Communication in a Trustzone-Assisted Hypervisor

Abstract

Virtualization technology allows the coexistence and execution of multiple operating systems on top of the same hardware platform. In the embedded systems domain, virtualization has been focused on the isolation of critical requirements like real-time, security and safety from non-critical characteristics. The strict confinement of guest partitions typically provided by virtualization does not suit the modular and inter-cooperative nature of embedded systems. The need for inter-partition communication has been addressed by multiple virtualization solutions, either to enable guest-level device para-virtualization or to ensure increased flexibility regarding cooperative partitions. However, the majority of existing approaches follow an ad hoc approach with limited to none applicability outside their solution's scope.This paper presents TZ-VirtIO, an asynchronous standardized inter-partition communication (IPC) mechanism on top of a TrustZone-assisted dual-OS hypervisor (LTZVisor). The implemented IPC uses the standard VirtIO transport layer. The experiments conducted on a physical platform show a scalable, high-bandwidth and low-overhead solution for both single-core and multi-core architectures.

ShieLD: Shielding Cross-Zone Communication Within Limited-Resourced IoT Devices Running Vulnerable Software Stack

“…Several solutions attempt to provide a secure communication infrastructure between partitions. LTZVisor [21] and TZ-VirtIO [22] are systems based on ARM Cortex-A utilizing TrustZone to setup hardwareassisted virtualization of the system into secure and nonsecure partitions. VM communication is established using VirtIO [23] and takes place such that every exchange of data between partitions is carried out through a shared memory (non-secure) which is overseen by the trusted hypervisor.…”

“…TrustZone has been very recently introduced in the Cortex-M family and to the best of our knowledge, no work is done on secure cross-world communication in TrustZone-M. The above mentioned solutions for cross-world communication are vulnerable to man-inthe-middle attacks, malicious RTOS and hardware tampering [21], [22], [24], [25]. ShieLD eliminates the risk of former two security threats by ensuring the security of cross-world communication for data exchange between processes.…”

MCS-IOV: Real-Time I/O Virtualization for Mixed-Criticality Systems

“…LTZVisor [60] and TZDKS [31] proposed MCS architectures using Trust-Zone technologies, which achieve better system performance compared to traditional TDMA-based approaches. Pinto et al then proposed Virtual-IO [56] based on LTZVisor, which achieves a MCS I/O system with predictable I/O timing. The main limitations of the TrustZone-based approach are twofold: 1) only two system modes can be supported; and 2) no adaptive I/O resource management upon mode switches at runtime supported.…”

Interdomain I/O Optimization in Virtualized Sensor Networks

“…For big data and latency-sensitive applications in virtualized systems, memory is increasingly becoming a bottleneck, and memory efficiency is critical for the high-performance execution of VMs, especially for changing workloads [7,56,57]. Modern complex embedded systems use memory partitioning to satisfy a wide set of nonfunctional requirements, such as strong temporal and spatial isolation [8,58,59]. Oliveira et al [58] presented TZ-VirtIO, an asynchronous standardized interpartition communication (IPC) mechanism on top of a trust zone-assisted dual-OS hypervisor (LTZVisor) using a standard VirtIO transport layer.…”

“…Modern complex embedded systems use memory partitioning to satisfy a wide set of nonfunctional requirements, such as strong temporal and spatial isolation [8,58,59]. Oliveira et al [58] presented TZ-VirtIO, an asynchronous standardized interpartition communication (IPC) mechanism on top of a trust zone-assisted dual-OS hypervisor (LTZVisor) using a standard VirtIO transport layer. Smith et al [60] proposed a system for dynamically allocating memory amongst virtual machines at runtime, and they evaluated six allocation policies implemented within the system.…”