System Virtualization On New Generation Mobile Computing Platform And Its Applications

With the saturation of the PC market, the era of"Post PC"is coming. Various mobile devices, such as netbooks, smartphones, tablet PCs, music players and portable game consoles, are increasingly popular and have become the new generation platform for mobile computing. In particular, the advances of smartphone and tablet PC are phenomenal: they have a huge number of users, very powerful hardware and rich applications, and play a significant role in people's daily life.However, these new mobile devices are also facing many problems and challenges. For example, with more hardware components and applications are integrated together, the whole system becomes increasingly complicated and unrealiable. More and more viruses, Trojans horses, malware and spyware are targeting at smartphones and tablet PCs, imposing threats on user privacy and information security. Powerful funcationalities require high power consumption but battery technologies advance slowly, which limits many applications. User data are distributed on different devices, making it hard for users to manage their devices and data, etc.This paper studies how to leverage system virtualization technologies to solve the key problems on the new generation mobile computing platform, including the following three main parts.1. System reliabity and security. This paper studied how to leverage virtual machine techniques to improve the reliability and security of mobile devices. As ARM is the most popular architecture for mobile devices, this paper studied how to do virtualization for ARM CPU and memory, and designed and implemented a virtual machine monitor for ARM platform, called MobiVMM, to simultanesouly run multiple virtual machines on a single physical ARM device. Different virtual machines are strongly isolated and can run different operating systems. By running different applications in different virtual machines, the realiabilty and security of the whole system can be significantly improved: even if a virtual machine crashes or is attacked, other virtual machines can still run smoothly. Besides studying how to virtualize ARM architecture, MobiVMM is specially designed for mobile devices. It emphases efficient utilization on various system resources and provides support for real-time. MobiVMM is the first VMM designed for ARM architecture from scratch. It has small code base, high power efficiency and fast system response time.2. User privacy protection in device sharing. Mobile devices, particularly mobile phones, are truely personal devices and often store various personal data, such as call history, text messages, contacts, photos and videos. When sharing a mobile device with other people, these private data must be protected. Yet existing mobile devices cannot provide sufficient support in privacy protection. This paper deeply studied the user behaviors in device sharing and designed and implemented the first solution, called xShare, to protect user privacy in device sharing. xShare leverages operating system level virtualization to protect user privacy in device sharing. It can dynamically create a virtual running environment inside the operating system for device sharing. In the virtual running environment, only those data and applications which are explicitly shared by the device owner are visible. Consequently, the unshared private data are effectively protected. The system implementation of xShare has good performance, is easy to use, and can meet the real needs for users to protect their privacy in device sharing. xShare was published in Mobisys and invited to IEEE Transactions on Mobile Computing (TMC) as one of the five best papers. The extended version was further selected as the spotlight paper of the issue of IEEE TMC.3. Portable user computing environment. Many users use multiple computing devices in their daily life. Those devices locate in different places, have different system settings, run different applications, and store different user data. As a result, users have to spend significant time and effort to manage those devices and their data. To solve this problem, this paper studied how to leverage application virtualization to create a portable user computing environment, so that users can use the same applications and access the same data on different devices. This paper further designed and implemented DevicePort system, which is able to decouple the already-in-use applications from the underlying operating system and make them portable across different devices. The system implementation of DevicePort can support a large number of everyday applications and run them in their native speed, and is easy to deploy. Compared with the VM-based solutions, DevicePort has significant performance improvements in terms of both application launch latency and CPU usage, and is much easier to use.The above three parts cover system virtualization technologies in there different layers: the hardware level virtualization, the operating system level virtualization, and the application level virtualization. To solve the practical problems on the new generation platform of mobile computing, real systems are designed and implemented and complehensive evaluations are performed. With the above research and innovations, this paper provides new insights and directions for solving more problems on the new generation mobile computing platform.