Since January 2013, Takahiro Hirofuchi is visiting ASCOLA Research Group of Ecole des Mines de Nantes, France. He is working together with Dr. Adrien Lebre, developing the virtual machine support of a famous and widely-used simulation framework (SimGrid).
At the moment of this writing, code is still under development. But, it's already started being used by other research projects. For enthusiasts (?), it is publicly available in the hypervisor branch of the SimGrid repository.