Virtual Machine principles

1. Virtual Machine principle: Virtual Machine (VM), as its name implies, is a virtual computer. Simply put, virtual machines use software to simulate the hardware and software of a computer.

A complete running environment is established by sharing some hardware of the host and some Virtual Hardware simulated by the host CPU. The actual root of the system installed by the Virtual Machine

There is no difference in the computer operating system, and it will also be infected with viruses. However, because the virtual machine is a closed virtual environment, if the network connection between the virtual machine and the host machine is excluded, no
The network of the host and host is affected.

In a virtual machine, the central processor chip divides the storage area from other parts of the system, and the operating system and application program run.

In the "protection mode" environment. If a program is frozen in a virtual machine, the operation of the program running outside the virtual machine and the normal operation of the operating system will not be affected. In

In a real computer system, the device driver in the operating system is responsible for controlling hardware resources and converting system commands into specific device control languages. Assume that the device ownership is independent

This makes it impossible for a single computer to run multiple operating systems concurrently. Virtual machines include technologies to overcome this limitation. The virtualization process introduces the lower layer

The interaction of device resource redirection does not affect the high-level application layer. Through virtual machines, you can run multiple operating systems concurrently on a single computer.

2. The purpose of using virtual machines: to do a lot of work that cannot or cannot be done directly on the host machine.

For example, open multiple windows for playing games, install various operating systems in experiments, install new software in experiments, and test viruses and hacking tools ......