A Two-Step Execution Mechanism for Thin Secure Hypervisors
Manabu Hirano, Takahiro Shinagawa, Hideki Eiraku, Shoichi Hasegawa, Kazumasa Omote, Koichi Tanimoto, Takashi Horie, Seiji Mune, Kazuhiko Kato, Takeshi Okuda, Eiji Kawai, Suguru Yamaguchi · 2009
Virtual machine monitors (VMMs), also called hypervisors, can be used to construct a trusted computing base (TCB) enhancing the security of existing operating systems. The complexity of a VMM-based TCB causes the high risk of security vulnerabilities. Therefore, this paper proposes a two-step execution mechanism to reduce the complexity of a VMM-based TCB. We propose a method to separate a conventional VMM-based TCB into the following two parts: (1) A thin hypervisor with security services and (2) A special guest OS for security preprocessing. A special guest OS performing security tasks can be executed in advance. After shutting down the special guest OS, a hypervisor obtains preprocessing security data and next boots a target guest OS to be protected. Thus, the proposed two-step execution mechanism can reduce run-time codes of a hypervisor. This paper shows a design, a prototype implementation and measurement results of lines of code using BitVisor, a VMM-based TCB we have developed.