1. A method of controlling a computer system with a plurality of processors having a hardware-assisted virtualization and a memory, the computer system comprising a first processor group of the processors having hardware-assisted virtualization set disabled among the plurality of processors, and a second processor group of the processors and having hardware-assisted virtualization set enabled among the plurality of processors, the method comprising: a first step of booting a first OS by assigning the first processor group to the first OS; a second step of booting a virtual machine monitor to boot a virtual machine by assigning the second processor group to the virtual machine monitor; a third step performed by the virtual machine monitor, the third step booting a second OS by assigning a certain area of the memory to the second OS; and a fourth step performed by the virtual machine monitor, the fourth step setting a data path through which the first OS and second OS communicate with each other, the data path being set in the memory.