Libvmi: A Library for Bridging the Semantic Gap between Guest OS and VMM

Semantic gap is one of the most important problems in the virtualized computer systems. Solving this problem not only helps to develop security and virtual machine monitoring applications, but also benefits for VMM resource management and VMM-based service implementation. In this paper, we first review the general architecture of virtual computer systems, especially the interaction principles between Guest OS and VMM so as to better understand the causes of semantic gap. Then we consider how to build a library that can integrate the commonalities existing in different VMMs and Guest OSes. It should be general enough to facilitate the above mentioned applications development. In order to more clearly illustrate this issue, we select Libvmi as the case study, elaborating its design philosophy and implementation. Finally, we describe how to use Libvmi with two application examples and verify its correctness and effectiveness.