Toward an Analysable, Scalable, Energy-Efficient I/O Virtualization for Mixed-Criticality Systems

In mixed-criticality systems (MCSs), timely handling of I/O operations is a key for the system being successfully implemented and appropriately functioned. The I/O system for an MCS must simultaneously enable different features, including isolation/separation, timing-predictability, performance, scalability, and energy-efficiency. Moreover, such an I/O system also requires to manage I/O resource in an adaptive manner to facilitate efficient yet safe resource sharing among components of different criticality levels. Existing approaches cannot achieve all of these requirements simultaneously. This article presents a mixed-criticality I/O management framework, termed MCS-IOV. MCS-IOV is based on hardware-assisted virtualization, which provides temporal and spatial isolation and prohibits fault propagation with limited extra overhead. MCS-IOV extends a real-time I/O virtualization system, by supporting the concept of mixed criticalities and customized interfaces for schedulers, which offers good timing predictability and scalability. Finally, we introduce an energy management framework for MCS-IOV, ensuring the power-efficiency of the design. The MCS-IOV is the first systematical solution that fulfills all the requirements as a mixed-criticality I/O system.

I. Introduction

Safety-critical systems have stringent assurance and verification requirements that are absolutely essential to many life-critical applications, including medical, automotive, aerospace, and industrial automation [8], [45]. In safety-critical systems, integrating components with different levels of criticalities (e.g., automotive safety and integrity levels (ASILs) in ISO26262 [1]) onto a shared hardware platform has become increasingly important [8], [45]. One of the examples is the leading automotive companies are devoting themselves to integrating the advanced driving assistance system (ADAS, a critical component) and the in-vehicle information system (IVIS, a less-critical component) in a shared platform [43], due to size, weight, power, and cost (SWaP-C) requirements [1], [45]. This new trend has brought a lot of interest from both academia and industry to work on systems with mixed-criticality levels, known as mixed-criticality systems or MCSs [8]. The rapid growth of the theory has therefore imposed more demands on the underlying hardware and execution platforms used by modern safety-critical systems [24], which is required to have diverse functionalities to align with the MCS execution model that can be beneficial for timing verification with reduced costs.