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Date:   Thu, 23 Jun 2022 10:23:57 +0200
From:   Joerg Roedel <joro@8bytes.org>
To:     Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc:     linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
        robin.murphy@arm.com, ashish.kalra@amd.com, vasant.hegde@amd.com,
        thomas.lendacky@amd.com
Subject: Re: [PATCH v3 7/7] iommu/amd: Do not support IOMMUv2 APIs when SNP
 is enabled
Message-ID: <YrQjHYsEIGN0mtO2@8bytes.org>
References: <20220622171131.11870-1-suravee.suthikulpanit@amd.com>
 <20220622171131.11870-8-suravee.suthikulpanit@amd.com>
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On Wed, Jun 22, 2022 at 12:11:31PM -0500, Suravee Suthikulpanit wrote:
>  bool amd_iommu_v2_supported(void)
>  {
> -	return amd_iommu_v2_present;
> +	/*
> +	 * Since DTE[Mode]=0 is prohibited on SNP-enabled system
> +	 * (i.e. EFR[SNPSup]=1), IOMMUv2 page table cannot be used without
> +	 * setting up IOMMUv1 page table.
> +	 */
> +	return amd_iommu_v2_present && !amd_iommu_snp_en;

IOMMU_v2 APIs could actually be supported with GIOV and IOMMUv2
page-tables in-use, no?

Regards,

	Joerg