JustKernel

Xen architcture

dom0 dom1 dom2

(guest OS) (guest OS) (guest OS)

—————-Xen Hypervisor————————-

——————-Hw Resources————————

dom0 priviledged – ring 0 , mostly linux

dom1 , dom2 … domN – unpriviledged ring 3

Role of dom0:

• This is the first guest to run when Xen starts
• Handling devices, including multiplexing of them for VMs
• Implementing half of the split device driver (the other half in domU)
• handling administrative task
• providing User interface to the hypervisor.

Here in Xen, dom0 controls the other OS. Dom 0 is the master dom. But this doesn’t happen in CoLinux . Both the kernels, (host and guest) are given equal processor time. Here even a guest driver executes at ring 0.

Anshul Makkar, anshul_makkar@justkernel.com

Originally Posted On: 2011-07-15 18:17:39

Tags: xen