Virtualization Embedded Controller Interface

Virtualization Embedded Controller Interface, abbreviated as VECI, is a technology used for Intel Virtualization Technology (Intel VT) in chipsets that support Core 2 Duo microprocessors.

Details

The VECI bus allows the Virtualization Engine (VE) integrated in the CPU to communicate directly with the Virtualization Engine (VE) integrated in the chipset. This 100 MHz bi-directional sideband bus enables the VEs to cross-communicate and synchronize virtualization events. The bus consists of two pairs of differential transmit and receive signals, allowing quick messaging which minimal pin-count and routing.

Intel VT requires two distinctly different Virtualization Engines which must cooperate to fully enable system-level virtualization (SLV). The North VE (NVE) primarily virtualizes the CPU's pipelining and out-of-order execution. The South VE (SVE) primarily virtualizes devices (DMA, IO, and Memory). Through VE-VE communication, the NVE and SVE are able to cooperatively virtualize the cache, providing significant performance gains to virtualized environments.

Virtualizing the cache significantly reduces snoops for virtualized upstream memory traffic, and additionally reduces cache-misses for virtualized events within the CPU.

Signalling

In addition to being differential, the VECI bus must be A/C coupled since the CPU and chipset do not typically operate at the same core voltage.

References

* cite web
last = Shridhar
first = Radhakrishna Hiremane
title = Intel Software Network Blogs >> Hardware assists for I/O virtualization
url = http://softwareblogs.intel.com/2007/10/26/hardware-assists-for-io-virtualization/
accessdate = 2008-01-15
* cite web
title = Intel Virtualization Technology – Overview
url = http://www.intel.com/technology/platform-technology/virtualization/
accessdate = 2008-01-16
* cite web
last = Torres
first = Gabriel
title = Intel Virtualization Technology (VT) Explained
url = http://www.hardwaresecrets.com/article/263
accessdate = 2008-01-16
* cite web
last = Holland
first = Doug
title = Intel Software Network Blogs >> Virtualization for the Software Engineer
url = http://softwareblogs.intel.com/2007/06/16/virtualization-for-the-software-engineer/
accessdate = 2008-01-16

ee also

* x86 virtualization
* virtual machine
* Virtualization
* Partial virtualization