CSR-EHS: Real-Time Hierarchical Hypervisors

虚拟化是网络系统中保障安全和容错的关键技术。对虚拟化的硬件支持允许子系统隔离，这可以极大地限制攻击者或硬件和软件故障造成的损害。这个项目研究了两个问题，解决当前虚拟化技术的严重限制：正确地支持实时操作系统，并允许递归虚拟化的hypervisor的设计，强制隔离的系统层。该项目正在对设计框架进行详细研究，使管理程序能够运行硬实时客户机，并能够参与递归虚拟化。更重要的是，系统管理程序的透明性得到了维护，以支持分层虚拟化，从而可以运行现成的商业操作系统，而无需修改它们的代码。对于非抢占式的实时资源调度，各种资源划分算法和它们的影响，满足时间约束，包括I/O的需要。该项目的目标是一个实时就绪的分层虚拟机管理程序。该项目的结果预计将影响许多类型的实时嵌入式应用程序的成功部署，这些应用程序越来越多地联网。这些应用包括交通系统、医疗设备、老年人辅助生活、环境监测、军事系统等。该项目的成功预计将为部署安全和容错的传感器/执行器网络提供基础技术，这将使整个社会受益。该项目的技术见解正在被纳入大学计算机科学课程。

Virtualization is a key technology for safeguarding security and fault-tolerance purposes in networked systems. Hardware support for virtualization allows subsystem isolation to be achieved that can greatly limit the damage caused by an attacker or by hardware and software failures. This project studies two issues that address severe limitations on current virtualization technology: to properly support a real-time operating system, and to allow for recursive virtualization in the design of the hypervisor, the system layer that enforces isolation. The project is conducting a detailed study of a design framework whereby the hypervisor is capable of running hard real-time guests and also capable of participating in recursive virtualization. More importantly, the transparency of the hypervisor is maintained to support hierarchical virtualization, so that off-the-shelf commercial operating systems can be run without having to modify their code. For non-preemptive real-time resource scheduling, various resource partitioning algorithms and their implications on meeting timing constraints are considered, including I/O needs. The goal of this project is a hierarchical hypervisor that is real-time ready. The result of this project is expected to impact the successful deployment of many types of real-time embedded applications that are increasingly networked. These applications span transportation systems, medical devices, assisted living for the elderly, environmental monitoring, military systems and others too many to mention. Success in this project is expected to provide the foundational technologies for deploying secure and fault-tolerant sensor/actuator networks that will benefit society at large. Technical insights from this project are being incorporated into university computer science classes.