In computing, hardware-assisted virtualization is a platform virtualization approach that enables efficient full virtualization using help from hardware capabilities, primarily from the host processors. Full virtualization is used to simulate a complete hardware environment, or virtual machine, in which an unmodified guest operating system (using the same instruction set as the host machine) executes in complete isolation. Hardware-assisted virtualization was added to x86 processors (Intel VT-x or AMD-V) in 2005 and 2006 (respectively).
Hardware-assisted virtualization is also known as accelerated virtualization; Xen calls it hardware virtual machine (HVM), and Virtual Iron calls it native virtualization.
Hardware-assisted virtualization first appeared on the IBM System/370 in 1972, for use with VM/370, the first virtual machine operating system. With the increasing demand for high-definition computer graphics (e.g. CAD), virtualization of mainframes lost some attention in the late 1970s, when the upcoming minicomputers fostered resource allocation through distributed computing, encompassing the commoditization of microcomputers.
IBM offers hardware virtualization for its POWER CPUs under AIX (e.g. System p) and for its IBM-Mainframes System z. IBM refers to its specific form of hardware virtualization as "logical partition", or more commonly as LPAR.