2. 虚拟化的定义
尚无权威的定义
Wikipedia 的定义
Platform virtualization is performed on a given hardware platform
by host software (a control program), which creates a simulated
computer environment, a virtual machine, for its guest software.
The guest software is not limited to user applications; many hosts
allow the execution of complete operating systems. The guest
software executes as if it were running directly on the physical
hardware, with several notable caveats. Access to physical system
resources (such as the network access, display, keyboard, and disk
storage) is generally managed at a more restrictive level than the
processor and system-memory. Guests are often restricted from
accessing specific peripheral devices, or may be limited to a subset
of the device's native capabilities, depending on the hardware
access policy implemented by the virtualization host.
举例说明更容易理解