RE: [RFC PATCH 2/6] iommu/amd: Add support for hw_info for iommu capability query

[Tian, Kevin]

> From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
> Sent: Wednesday, December 13, 2023 12:02 AM
> 
> +void amd_iommu_build_efr(u64 *efr, u64 *efr2)
> +{
> +	if (efr) {
> +		*efr = (FEATURE_GT | FEATURE_GIOSUP | FEATURE_PPR);
> +
> +		/* 5-level v2 page table support */
> +		*efr |= ((FEATURE_GATS_5LEVEL << FEATURE_GATS_SHIFT) &
> +			 FEATURE_GATS_MASK);
> +
> +		/* 3-level GCR3 table support */
> +		*efr |= ((FEATURE_GLX_3LEVEL << FEATURE_GLX_SHIFT) &
> +			 FEATURE_GLX_MASK);
> +
> +		/* 16-bit PASMAX support */
> +		*efr |= ((FEATURE_PASMAX_16 << FEATURE_PASMAX_SHIFT)
> &
> +			 FEATURE_PASMAX_MASK);
> +	}
> +
> +	if (efr2)
> +		*efr2 = 0;
> +}

Don't this need to check the support in hw?