Windows Virtualization Architecture.ppt

An Overview of Virtual Machine Architectures Slide sources Virtual Machines Background, Kenneth Chiu, Computer Science Department at SUNY Binghamton kchiu@ Windows Virtualization Architecture, Mark Kieffer, Group Program Manager, Windows Virtualization,Microsoft Corporation CS 140 Lecture 26: Virtual Machine Monitors, Mendel Rosenblum, Stanford CS Department An Overview of Virtual Machine Architectures, Smith and Nair Smith and Nair, Virtual Machines, Versatile Platforms for Systems and Processes, Elsevier 2005 Review: What is an OS? software between applications and reality: abstracts hardware and makes portable makes finite into (near)infinite provides protection What If? Process abstraction looked just like hardware! Virtual Machines A virtual machine treats hardware and the operating system kernel as though they were all hardware. A virtual machine provides an interface identical to the underlying bare hardware. For example, the operating system creates the illusion of multiple processes, each executing on its own processor with its own (virtual) memory. The resources of the physical computer are shared to create the virtual machines. A normal user time-sharing terminal serves as the virtual machine operator’s console. System Models Definitions Instruction Set Architecture (ISA) Precise specification of the interface between hardware and software Application Binary Interface (ABI) Defines how an application can work with a platform at the binary level. (Contrast with API.) Includes user ISA, system call interface, etc. Suppose an ABI is changed. Recompile? Source changes? Virtualization VMM also known as hypervisor. Advantages/Disadvantages of Virtual Machines The VM concept provides complete protection of system resources since each VM is isolated from all other VMs. What might be bad about this? Isolation, however, permits no direct sharing of resources. A VM system is a perfect vehicle for OS research and development. The VM concept is difficul