Virtualization four, KVM virtualization technology

First, KVM overview

1. KVM

kernel-based virtual machine kernel-based VMS

Israel Qumranet Company developed, is a module of the kernel

Developed in 2006, 2008 were acquired by Redhat

Rely on KVM technology: Intel VT-X,AMD amd-v

2. The system operation mode after the KVM module is loaded

Kernel mode: Guestos perform I/O class operations, or other special instructions

User mode: On behalf of Guestos to request I/O class operations,

Guest Mode: Guestos non-I/O class operation, in fact, it is called the virtual machine user mode

3. KVM Components

Two types of components:

/DEV/KVM: Work in hypervisor, in user space through the IOCTL () system call to complete the VM creation, startup and other management functions, it is a character device,

Features: Create VMS, allocate memory for VMS, read and write Vcpus registers, inject interrupts to CPU, run Vcpus, etc.

Virtualization four, KVM virtualization technology