Nonroot-Process:A Process Abstraction Layer Based-on The Hardware-Assisted Virtualization

With the rapid development of cloud computing technology, it has been a great challenge for the server applications to meet up with the demands of performance. Moreover, the situation becomes worse as the traditional OS architecture makes quite common abstractions. In addition, as the virtualization is ubiquitous on the servers, the functional redundancy between the guest operating system and the underlying hardware abstraction layer puts additional performance loss on the server applications. In recent years, large amounts of research works which mainly focus on the lightweight design of the operating system have been done to solve these problems. Among these works, Exokernel with LibOS is the state-of-art.Our work starts with the design principles of Exokernel, which emphasizes that the OS should do fine-grained management and expose more hardware features to processes. After we made a thorough analysis on the isolation and abstraction of Intel’s VT-x Hardware-Assisted Virtualization technology, we put forward an idea of implementing an OS according to the isolation of VT-x. To demonstrate our idea, we designed and implemented a new process abstraction layer on the Linux Kernel, on which an normal executable binary can access the hardware features, which is not possible for processes that executing on the traditional environment.In this paper, the process which runs on the new abstraction layer is called "non-root process". Non-root process can access the hardware memory management features of Intel, which includes segment protection and paging. Moreover, error handling of the non-root process can be implemented by hardware exception directly. In addition, because of the decoupling of the loader and the real program, an unmodified executable binary could run directly as the non-root process.Our work on the system is listed as follows:1. Making a research on the major OS kernel architectures and the virtualization technologies.2. Deeply analyzing the Intel’s VT-x technology and solutions to implement a process abstraction layer with VT-x.3. Designing and implementing a new executing method for runnable binaries, and making an assessment on it.