摘要 |
<p>A virtual machine system is provided with a processor having only two privileged modes, a low privileged mode and a high privileged mode, and achieves both a security function for protecting digital copyrighted works or the like and an operating system switching function that guarantees system reliability. The virtual machine system is provided with a first and a second processor and executes a hypervisor on the first processor in the high privileged mode. An operating system on the second processor is executed by cooperation between the hypervisor running on the first processor and a program running on the second processor in low privileged mode. This eliminates the need for running the hypervisor on the second processor in the high privileged mode, thus allowing for execution on the second processor in the high privileged mode of a program for implementing the security function.</p> |