Intel G2120T CM8063701391600 User Manual

Datasheet, Volume 1

35

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

®

IA-32 Architectures Software Developer’s Manual, Volume 3B and is available at:

http://www.intel.com/products/processor/manuals/index.htm.

The Intel VT-d spec and other VT documents can be referenced at:

http://www.intel.com/technology/virtualization/index.htm.

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.

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 

TLBs) 

— This avoids flushes on VM transitions to give a lower-cost VM transition time 

and an overall reduction in virtualization overhead.