AcpiVTD

Overview

Constructs the DMA-Remapping (DMAR) ACPI table for Intel VT-d (Virtualization Technology for Directed I/O). Reads platform configuration from UEFI setup variables and PCD, builds DRHD, RMRR, ATSR, and RHSA sub-tables, sorts them by device scope, and installs the final DMAR table via the ACPI Table Protocol. The driver handles both single- and multi-segment PCI topology and supports interrupt remapping and hardware-accelerated DMA with optional DMA remapping.

Key Functions

• AcpiVTDDxeEntryPoint -- Module entry point; locates protocols, reads platform setup variables, drives DMAR construction
• BuildDmarTable -- Builds the complete DMAR table skeleton with header and container structures
• InsertDrhd -- Inserts DMA-Remapping Hardware Unit Definition (DRHD) sub-tables for each VT-d engine
• InsertRmrr -- Inserts Reserved Memory Region Reporting (RMRR) entries for USB/XHCI and graphics
• InsertAtsr -- Inserts Address Translation Service Reporting (ATSR) sub-tables for PCIe root ports
• SortSubTables -- Sorts DMAR sub-tables by segment group, bus number, and device/function per the ACPI specification

Dependencies

• UEFI Boot/Runtime Services
• ACPI Table Protocol
• PCD Protocol
• Setup Variable Protocol (platform-specific)

Platform

Intel x86-64 (PE32+), Purley platform (HR650X). UEFI subsystem.