linux-kernel - Re: [PATCH v3 7/7] iommu/amd: Do not support IOMMUv2 APIs when SNP is enabled

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <YrQjHYsEIGN0mtO2@8bytes.org>
Date:   Thu, 23 Jun 2022 10:23:57 +0200
From:   Joerg Roedel <joro@...tes.org>
To:     Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Cc:     linux-kernel@...r.kernel.org, iommu@...ts.linux-foundation.org,
        robin.murphy@....com, ashish.kalra@....com, vasant.hegde@....com,
        thomas.lendacky@....com
Subject: Re: [PATCH v3 7/7] iommu/amd: Do not support IOMMUv2 APIs when SNP
 is enabled

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