Hardware/Software Co-Design of Memory Page Translation for Mobile Virtualization

Virtualization has been a well-studied topic for traditional servers. As the demand for the support of virtualization on mobile devices emerged, it again became a popular research topic. However, most research work focused on the applications of mobile virtualization. Detailed knowledge of the characteristics of mobile devices is still lacking. In this paper, we focus on the memory management of mobile virtualization, and propose an optimized page translation oPT with hardware/software co-design. The usage pattern of mobile devices is also considered in the design so it is optimal in terms of the hit ratio of the second stage. The variability of translation time in the second stage is eliminated to provide nearly the same behavior as the non-virtualized architecture. We verify the correctness and feasibility of oPT with a formal proof and a comprehensive evaluation based on both software emulation and hardware implementation. The results indicate oPT can outperform the most popular method. The number of memory accesses is reduced by 51.38 to 56.01 percent, and the average translation time is reduced by 78.63 percent. In addition, the power consumption of the hardware unit in oPT is only about one third that of the traditional method.