Re: [PATCHv2 29/29] Documentation/x86: Document TDX kernel architecture

Xiaoyao Li
2022-02-24T09:09:08Z

On 1/24/2022 11:02 PM, Kirill A. Shutemov wrote:

> +#VE due to CPUID instruction
> +----------------------------
> +
> +In TDX guests, most of CPUID leaf/sub-leaf combinations are virtualized by
> +the TDX module while some trigger #VE. Combinations of CPUID leaf/sub-leaf
> +which triggers #VE are configured by the VMM during the TD initialization
> +time (using TDH.MNG.INIT).
> +

The description is incorrect.

TDH.MNG.INIT does not configure whether the CPUID leaf/sub-leaf triggers
#VE or not. It configures if some feature bits in specific leaf-subleaf
are exposed to TD guest or not.

Whether the CPUID(leaf, sub-leaf) causes #VE or not, is defined in TDX
spec, and not configurable by user or VMM.