Re: [PATCH v2 00/26] iommu/amd: Introduce AMD Hardware-accelerated Virtualized IOMMU (vIOMMU) Support

[Suthikulpanit, Suravee]

On 6/1/2026 8:30 PM, Jason Gunthorpe wrote:
> On Thu, May 28, 2026 at 05:17:12AM +0000, Suravee Suthikulpanit wrote:
>
> > [1] IOMMU Specification: https://docs.amd.com/v/u/en-US/48882_3.10_PUB
>
> This link doesn't work

AMD Documentation team have recently updated the doc and remove the old 
link :( Here is the most recent one.

https://docs.amd.com/v/u/en-US/48882_3.11_IOMMU_PUB

> And I'm not sure the older PDF has everything, I haven't figure out
> where in the spec this TransDevID stuff comes from

The term TransDevID is not mentioning in the spec. It's basically what 
we need to program into the VFCntlMMIO Offset {16’b[GuestID], 
6’b01_0000} Guest Miscellaneous Control Register bits [31:16] (DeviceID: 
The system deviceID which has the entire guest GPA to SPA translation).

The hardware expects driver to setup some unused DTE with the 
translation (Host Page Table Root Pointer [31:12], Mode[2:0], TV, V 
bits). So, I am referring to the device ID used as index of the unused 
DTE as TransDevID.

Suravee


> > [2] Linux git tree: https://github.com/AMDESE/linux-iommu/tree/linux-7.1.0-rc4-amd-viommu_upstream_v2
>
> Build test all the kconfig combinations, I noticed problems.
>
> Jason