Changes

Xen hardware virtual machine (HVM) virtualization provides support for the virtualization of unmodified guest operating systems. Where ever possible it is better to run paravirtualized guests because HVM domainU guests run slightly slower than paravirtualized domainU guests and require that without the host system contain a processor type with build loss of performance inherent in the use of full virtualization support. That said, if you need In systems containing CPUs with virtualization support the HVM approach provides similar levels of performance to virtualize an operating system which has not, or cannot be paravirtualization of modified to run as a paravirtualized Xen guest (such as Microsoft Windows) then HVM virtualization is a good solutionguests.  

In order to support full hardware virtualization, the CPU must include Intel-VT or AMD-V support. This can be verified using the following commands: