Thank you for the opportunity to help you with your question!
1.Control domain - management control point for the
server, used to configure domains and manage resources. It is the first domain
to boot on a power-up, is an I/O domain, and is usually a service domain as
2.I/O domain - has been assigned physical I/O
devices: a PCIe root complex, a PCI device, or a SR-IOV (single-root I/O
Virtualization) function. It has native performance and functionality for the
devices it owns, unmediated by any virtualization layer.
3.Service domain - provides virtual network and disk
devices to guest domains.
4.Guest domain - a domain whose devices are all
virtual rather than physical: virtual network and disk devices provided by one
or more service domains. In common practice, this is where applications are run.
Please let me know if you need any clarification. I'm always happy to answer your questions.