X86 Platform Equipment Virtualization Technology

Recently, system virtualization becomes the research hotspot of computer science and technology all over the world. The applications of server consolidation, network security, data recovery, high performance computing and trusted computing require more in terms of performance, security-and-reliability and scalability of system virtualization. Device virtualization focuses on performance, security, availability and etc.Firstly, with research on current device virtualization technology, a design to accelerating display device based on device emulation model is proposed and implemented. Cooperated with memory virtualization module, the status of write-access to display device would be tracked, and the Dirty-Bitmap would be accumulated for the display device emulator to re-draw the screen of the virtual machine to which this emulator serves. To evaluate the optimizing design, a specific test system is presented and runs comparatively. The test results indicate that this design improves system performance, eases the system I/O bottle-neck and enhance the scalability.Secondly, among current device virtualization models, emulation model and para-virtualization model are subject to different flaws. The former suffer from low performance and the latter would resort to patching guest OSes. To satisfy the performance requirement of the application usage model, with the X86's IOMMU hardware support, the design and implementation of a generic I/O device direct assign model are proposed. With this model, an I/O device can be assigned to a virtual machine, which can exchange data with device directly, including guest OS in virtual machine accessing MMIO space of the device and the assigned device performing DMA. Device direct assign model improves system performance in addition to security of data exchange greatly, without patching guest OSes. It's one of the significant contributions of this dissertation.Thirdly, the device direct assign model is applied to display, network and USB storage devices. A specific solution to virtualize device BIOS is presented as a part of display device direct assign implementation. Respectively, the three cases are tested comparatively. The performance evaluation demonstrates that device direct assign model performs most close to non-virtual environment, far exceeding device emulation model. Device direct assign model reduces software complexity as it need not patch guest OSes or device drivers, performs far better than traditional device virtualization models and utilizes IOMMU to ensure system security, which becomes the device virtualization trends.Finally, the device virtualization evolution is introduced and a brand new device virtualization architecture based on device self-virtualization is shown. With self-virtualization functionality, the devices can provide multiple interfaces, which is to be assigned to an individual virtual machine.