基于Intel VT-x的XEN全虚拟化实现

Full-Virtualization Implementation of XEN Based on Intel VT-x

由于X86体系结构对虚拟机支持的先天不足,基于此体系结构的虚拟机需要修改操作系统的源代码,称为泛虚拟化技术。泛虚拟化需要修改操作系统的源代码,故只能支持开源的操作系统,且这种虚拟机的实现也是比较困难的。为了解决这个问题,Intel公司提出了VT-x技术,该技术可以使虚拟机不需要修改操作系统的源代码,也就是所谓的全虚拟化技术,可以支持非开源的操作系统,且虚拟机的实现也比较简单。XEN是业界广泛看好的一款基于X86体系结构开源的虚拟机监视器,XEN 3.0开始实现了基于VT-x的全虚拟化技术,具有优越的性能和良好的体系结构。文中讨论了Intel的VT-x技术,并从CPU虚拟化、内存虚拟化和设备虚拟化三个方面介绍XEN实现全虚拟化的关键技术。

As the X86 architecture has congenitally defective support for virtual machine, the virtual machine based on the architecture need to modify the operating system source code, called Para-virtualization. Para- virtualization need to modify the operating system, which can only support the open source operating system, and the virtual machine is also more difficult to implement. To solve the problem, lntel Corporation proposed the VT- x technology, which enables virtual machine do not need to modify the operating system source code, that is, the so- called Full - virtualization, can support for the non- open source operating system, and the implementation of the virtual machine is also relatively simple. XEN is an open source virtual machine monitor based on X86 architecture, whose future is widespread optimistic hy the industry, and XEN 3.0 began to implement the Full - virtualization technology based on VT- x, which has a superior performance and good architecture. This paper focused on Intel＇ s VT - x technology, and introduced the key technologies about XEN implementing Full - virtualization from the prospects of CPU virtualization, memory virtualization and device virtualization.