RE: [RFCv2 PATCH 7/7] iommu/amd: Add nested domain attach/detach support

[Tian, Kevin]

> From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
> Sent: Friday, January 12, 2024 8:07 AM
> 
> 
> -	/* Use system default */
> -	tmp = amd_iommu_gpt_level;
> +	if (amd_iommu_domain_is_nested(pdom)) {
> +		/*
> +		 * For nested domain, guest provide guest-paging mode.
> +		 * We need to check host capability before setting the mode.
> +		 */
> +		tmp = pdom->guest_paging_mode;
> +		if (tmp > amd_iommu_gpt_level) {
> +			pr_err("Cannot support Guest paging mode=%#x
> (dom_id=%#x).\n",
> +			       pdom->guest_paging_mode, pdom->id);
> +			tmp = amd_iommu_gpt_level;
> +		}

why not returning error to the caller