The Kernel-based Virtual Machine Research And Its Event Tracking Mechanism

The rapid development of computer hardware and architecture makes the computing capacity of computer systems more powerful and lets the classic computing paradigm that one computer only run one Operating system and related software aboved it laggard. Since virtualization can make good use of hardware resource and give enough support to lot kinds of software, it makes a good tradeoff between quickly developing hardware and various complicated applications. The virtualization technology has been widely applied and researched. The hardware-assisted virtualization technology remedies the performance defect of software-based virtualization, brings a closely same performance for virtual machine to native physical machines and promotes some new virtualization solutions such as Kernel-based-virtual machine (KVM). Virtual machine is a hot topic in industrial and academic research, and one of the fastest growing technologies.This thesis summaries current research status of virtual machines, analyzes the supports of hardware-assisted technology for virtualization, investigates the theory and key technologies of virtual machine. Correlating with the source code reading and developing, the thesis discusses the architecture and some key implementations of KVM in detail, and implements a new event traces mechanism of KVM. The details are as follows:1. It divides the existing virtualization technology into different sorts according to the level of abstractions and introduced the properties of virtualization in each level. And it summaries the types of the hardware abstraction layer VMM and introduces two type of virtualization on the X86 platform, full-virtualization and pare-virtualization. Then it focuses on describing the implementation mechanism of CPU, memory and I/O operation's virtualization of hardware-assisted virtualization which makes up for software-based virtualization. At last it presents two virtualization solutions VMware and Xen.2. It studies in-depth the architecture and the theory of implementation of KVM, the interaction and interfaces between KVM and user-space applications, the initiation and creation of virtual machine, the mechanism of virtual MMU and I/O. It compared the performance to some other virtualizations solutions from various aspects by using common methods and analyses the test results. 3. In order to overcome the shortage of KVM tracing system, a new event traces mechanism was designed and implemented based on an in-depth understanding of Linux system trace and debug methods and common tools. All the codes had been submitted to KVM community and it provides a useful tool for debugging and performance tuning. Finally it looks to the future development and research work of KVM.