System virtualization is now available for mobile devices allowing for many advantages. Two of the major benefits from virtualization are system fault isolation and security. The isolated driver domain (IDD) model, a widely adopted architecture, enables strong system fault isolation by limiting the impact of driver faults to the driver domain itself. However, excessive I/O requests from a malicious domain to an IDD can cause CPU overuse of the IDD and performance degradation of applications in the IDD and other domains that share the same I/O device with the malicious do-main. If the IDD model is applied to mobile devices, this failure of performance isolation could also lead to battery drain, and thus it introduces a new severe threat to mobile devices. In order to solve this problem, we propose a fine-grained I/O access control mechanism in an IDD. Requests from guest domains are managed by an accounting module in terms of CPU usage, with the calcula-tion of estimated CPU consumption using regression equations. The requests are scheduled by an I/O access control enforcer ac-cording to security policies. As a result, our mechanism provides precise control on the CPU usage of a guest domain due to I/O device access, and prevents malicious guest domains from CPU overuse, performance degradation, and battery drain. We have implemented a prototype of our approach considering both network and storage devices with a real smart phone (SGH-i780) that runs two para-virtualized Linux kernels on top of Secure Xen on ARM. The evaluation shows our approach effectively protects a smart phone against excessive I/O attacks and guarantees availability.

Mobile phones security is becoming an important issue because they are being connected to an Internet through wireless modem technologies. System virtualization technology provides trusted computing capability by running isolated multiple virtual machines under hypervisor. In this paper, we propose a design of system virtualization for ARM CPU architecture and describe implementation of prototype called Xen on ARM using Xen hypervisor. Secure and nonsecure guest Linux virtual machines are executing under Xen on ARM isolated with each other and virtualization overhead is shown to be moderate compared to native Linux running on bare metal H/W.

Stateless computing is a new computing service focused on migrating user's computing contexts among different devices. In the near future, seamless computing will make computing environment easier to use and human centric. Users will not have spend time doing computing environment setup such as installation and upgrade. They will bring their own computing contexts, which consist of programs, files, and execution states, inside their pockets as saved in a small memory stick. The computing contexts will be restored on various devices, e.g. TV, desktops, mobile phone, PDA, etc. Our demonstration will show the early step to the seamless computing vision. We will demonstrate a seamless computing prototype which migrates computing contexts among different mobile embedded devices. The core technology inside the prototype which enables this computing state capability is the embedded virtual machine monitor (VMM), named as Secure Xen on ARM. We will migrate the whole state of a virtual machine between two HW platforms. Secure Xen on ARM run on the two platforms. A virtual machine running under the VMM on one platform is saved during its execution to USB memory stick, then the memory stick is plugged in to the other platform and the saved context is restored and continue execution of the virtual machine.

We will demonstrate a prototype of the beyond 3G mobile terminal based on system virtualization technology, which meets both security and flexibility requirements. In the proposed architecture, two domains, secure domain and normal domain, run on top of secure virtual machine monitor (VMM) which includes mandatory access control and domain integrity check mechanisms. Only security critical applications and services (e.g., banking, trading, and DRM) can run on the secure domain, and malware is prohibited from accessing the secure domain. Both flexibility and rich user experiences are provided by allowing users to install and execute application software, which might be potentially vulnerable, on the normal domain. Even in the case of malware attack, it cannot cause security threats to the secure domain because of the isolation and our access control features. This demonstration will show how secure our mobile terminal is against malware attacks compared to conventional single OS based mobile terminal.