Data Sheet

Datasheet, Volume 1 of 2 57
Technologies
• DMA remapping: for supporting independent address translations for Direct
Memory Accesses (DMA) from devices.
• Interrupt remapping: for supporting isolation and routing of interrupts from devices
and external interrupt controllers to appropriate VMs.
• Reliability: for recording and reporting to system software DMA and interrupt errors
that may otherwise corrupt memory or impact VM isolation.
Intel VT-d accomplishes address translation by associating transaction from a given I/O
device to a translation table associated with the Guest to which the device is assigned.
It does this by means of the data structure in the following illustration. This table
creates an association between the device's PCI Express* Bus/Device/Function (B/D/F)
number and the base address of a translation table. This data structure is populated by
a VMM to map devices to translation tables in accordance with the device assignment
restrictions above, and to include a multi-level translation table (VT-d Table) that
contains Guest specific address translations.
Figure 3-1. Device to Domain Mapping Structures