Red Hat ENTERPRISE LINUX 5 - VIRTUALIZATION GUIDE Manual page 393

Virtualized CPU
Xen
• Hardware-assisted virtualization is the technique used for full
virtualization with Xen and KVM (definition:
• Para-virtualization is a technique used by Xen to run Linux guests
(definition: Para-virtualization)
• Software virtualization or emulation. Software virtualization uses
binary translation and other emulation techniques to run unmodified
operating systems. Software virtualization is significantly slower
than hardware-assisted virtualization or para-virtualization.
Software virtualization, in the form of QEMU, is unsupported by
Red Hat Enterprise Linux.
Red Hat Enterprise Linux 5 supports hardware-assisted, full
virtualization with the Xen and KVM hypervisors and software para-
virtualization with the Xen hypervisor for hosting Red Hat Enterprise
Linux guests.
A system has a number of virtual CPUs (VCPUs) relative to the
number of physical processor cores. The number of virtual CPUs is
finite and represents the total number of virtual CPUs that can be
assigned to guest virtual machines.
Red Hat Enterprise Linux supports the Xen hypervisor and the KVM
Kernel-based Virtual
hypervisor (refer to
have different architectures and development approaches. The Xen
hypervisor runs underneath a Red Hat Enterprise Linux operating
system which acts as a host managing system resources and
virtualization APIs. The host is sometimes referred to as as
Domain0.
Full virtualization)
Machine). Both hypervisors
dom0
or
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