Technologies
36
Datasheet
3
Technologies
3.1
Intel
®
Virtualization Technology
Intel Virtualization Technology (Intel VT) makes a single system appear as multiple
independent systems to software. This allows multiple, independent operating systems
to run simultaneously on a single system. Intel VT comprises technology components
to support virtualization of platforms based on Intel architecture microprocessors and
chipsets. Intel Virtualization Technology (Intel VT-x) added hardware support in the
processor to improve the virtualization performance and robustness. Intel Virtualization
Technology for Directed I/O (Intel VT-d) adds chipset hardware implementation to
support and improve I/O virtualization performance and robustness.
Intel VT-x specifications and functional descriptions are included in the
Intel
®
64 and
IA-32 Architectures Software Developer’s Manual, Volume 3B
and is available at:
http://www.intel.com/products/processor/manuals/index.htm.
3.1.1
Intel® VT-x Objectives
Intel VT-x provides hardware acceleration for virtualization of IA platforms. Virtual
Machine Monitor (VMM) can use Intel VT-x features to provide improved reliable
virtualized platforms. By using Intel VT-x, a VMM is:
•
Robust—
VMMs no longer need to use paravirtualization or binary translation. This
means that they will be able to run off-the-shelf OSs and applications without any
special steps.
•
Enhanced—
Intel VT enables VMMs to run 64-bit guest operating systems on IA
x86 processors.
•
More reliable—
Due to the hardware support, VMMs can now be smaller, less
complex, and more efficient. This improves reliability and availability and reduces
the potential for software conflicts.
•
More secure—
The use of hardware transitions in the VMM strengthens the
isolation of VMs and further prevents corruption of one VM from affecting others on
the same system.
3.1.2
Intel
®
VT-x Features
The processor core supports the following Intel VT-x features:
• Extended Page Tables (EPT)
— EPT is hardware assisted page table virtualization
— It eliminates VM exits from guest OS to the VMM for shadow page-table
maintenance
• Virtual Processor IDs (VPID)
— Ability to assign a VM ID to tag processor core hardware structures (such as