When I read some articles about VMM, I always don't understand what VMM is what is in the end, including a classic VAX VMM security kernel. The brother's sentence woke up me. Thevmm is actually a simple operating system. It provides a lot of abstraction Virtual machines can make multiple operating systems simultaneously run, even these operating systems don't need to be the same. From the system's perspective, every virtual machine at this time is actually a process of VMM this OS, although it looks more strange , More difficult to understand.
Pass by VMM may be guaranteed by running in the highest privilege level. On the other hand, in order to be thorough, VMM must be small enough. Therefore, in this sense, VMM is a simplest operation. System. It has a traditional OS process management, memory management, device management, and simplifies as much as possible. For simple, memory can even be static. For simple, VMM does not need to support a variety of devices, only need to have the most basic driver Even so, the driver is also a big burden on the first class of virtual machines. At the glazing, the security is the first, the efficiency is the second.
