Nov 29th, 2011
The Xen Hypervisor Platform
The Xen Hypervisor Platform
The Xen Hypervisor Platform is comprised of two components – the Xen hypervisor which is responsible for the core hypervisor activities such as CPU, memory virtualization, power management and scheduling of virtual machines.
The Xen hypervisor loads a special, privileged virtual machine called Domain0 or dom0. This virtual machine has direct access to hardware and provides device drivers and I/O management for virtual machines.
Each virtual machine, known as an unprivileged domain or domU, contains a modified Linux kernel that instead of communicating directly with hardware interfaces with Xen hypervisor.
CPU and memory access are handled directly by the Xen hypervisor but I/O is directed to domain 0. The Linux kernel includes “front end” devices for network and block I/O. Requests for I/O are passed to the “back end” process in domain 0 which manages the I/O.
