Intel Vt-d Technology In Kvm Virtual Machine

Nowadays, with the wide using of information technology in all walks of life, there were some requirements such as information resource management and service consolidating etc. As a solution scheme, virtualization technology has become a hot topic, especially the advance of cloud computing technology, the virtual machine technology is experiencing resurgence. Virtualization is a technology that combines computing resources to independent one or that divides them to many operating environments using methodologies like hardware and software partitioning or aggregation, which achieves all of the requirements. Virtualization technology find important applications over a wide range of areas such as server consolidation, kernel debugging, programme development, trusted computing platforms, supporting multi-OS environment, system migration, etc, resulting in widespread usage. Therefore, how to improve the security and performance of virtual machine becomes a hot topic. Virtual I/O technology, as one of core components in virtualization technology, has no significant development since device emulator virtual I/O and Para-virtualization device driver virtual I/O been designed.In response to market and technology request, Intel launched VT-d, a technology to support virtual machine inside the chipset, which can improve the I/O performance of VM, as well as OS rebustness and reliability. Based on KVM and Xen's advantage of open sourcing, Intel Linux VMM team adds to it VT-d support. The author participated in the project, and focused on the research of VT-d and its implementation for KVM.The paper introduced virtualization technology and the famous virtualization projects firstly, analysed the architecture of KVM and device virtualization. Then it discussed the principle and implementation of popular virtual I/O models currently, and did a simple analysis of their advantages and disadvantages. This paper did lots of work on research of VT-d, the overall design of direct I/O virtualization model, the implement of this model on KVM, and the performance analysis and evaluation. Finally, a series of data by performance testing demonstrated that the model with VT-d has advanced performance both on I/O device and CPU.