The Development Of Drivers For Virtual Machines - 1074 Words

I. Introduction to the topic This paper will be analyzing the development of drivers for virtual machines, as well as how virtual machines access host hardware. Topics covered will include what interest what interest I/O driver virtualization holds for the computer information science field, a general overview of virtualization, I/O hardware virtualization, and virtualization of I/O drivers. II. Why the topic is of interest Due to increased efficiency in Central Processing Units, most computers today are not used to their full potential. In fact, time interrupt handlers are issued as wait time, thus eating up CPU clock cycles. Virtualization gave the opportunity for multiple x86 Operating Systems to run on one machine. As CPU’s were†¦show more content†¦CPU, memory and resources are divided amongst the OSes by the Virtual Machine Monitors, where the Virtual Machine resides. The Virtual Machine is a software abstraction that will behave as though it is a complete machine, with virtual hardware resources, RAM, and I/O hardware [1]. There are two main approaches to virtualization: hosted architecture, and hypervisor architecture. In hosted architecture, the encapsulation layer is installed in the form of an application on the Operating System, while the hypervisor architecture involves the installing of the encapsulation layer, or hypervisor, on a clean system, which gives direct access to the system’s resources [2]. The issue of virtualization is that the virtualized OSes do not have full access to hardware resources and memory. They expect to execute within a high privilege level. The VMM is run in this high layer, while the OS is moved to the user level, above the application level. This change in privilege requires costly saving and restoring, and system calls can lead to some CPU cache loss. Instead, a translation look-aside buffer, or TLB, is used upon VMM entry and exit to cache physical and virtual address translation [3]. Because different privilege levels also effect semantics, binary translation is used to make up for the move. Three possibilities exist to allow virtualization: full virtualization with binary translation,