What exactly is VT-d2?
What features does it include?
Is Interrupt Remapping a VT-d2 feature?
VT-dstands for Intel Virtualization for Directed I/O. "VT-d2" appears to be an informal and internal name for Intel Core i7 Processor VT-d capabilities.Included in these capabilities are (a) I/O device assignment, (b) DMA remapping, (c) interrupt remapping, and (d) reliability features.
You can read about VT-d in detailat:
Click on the link entitled "Intel Virtualization Technology (Intel VT) for Directed I/O (Intel VT-d) Architecture Specification".