From: Suravee Suthikulpanit via iommu <iommu@lists.linux-foundation.org>
To: <iommu@lists.linux-foundation.org>
Cc: thomas.lendacky@amd.com, ashish.kalra@amd.com,
vasant.hegde@amd.com, robin.murphy@arm.com
Subject: [PATCH v2 7/7] iommu/amd: Do not support IOMMUv2 APIs when SNP is enabled
Date: Wed, 15 Jun 2022 20:55:41 -0500 [thread overview]
Message-ID: <20220616015541.11207-8-suravee.suthikulpanit@amd.com> (raw)
In-Reply-To: <20220616015541.11207-1-suravee.suthikulpanit@amd.com>
The IOMMUv2 APIs (for supporting shared virtual memory with PASID)
configures the domain with IOMMU v2 page table, and sets DTE[Mode]=0.
This configuration cannot be supported on SNP-enabled system.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
drivers/iommu/amd/init.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index bc008a82c12c..780d6977a331 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -3448,7 +3448,12 @@ __setup("ivrs_acpihid", parse_ivrs_acpihid);
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;
}
EXPORT_SYMBOL(amd_iommu_v2_supported);
--
2.32.0
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prev parent reply other threads:[~2022-06-16 1:56 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-16 1:55 [PATCH v2 0/7] iommu/amd: Enforce IOMMU restrictions for SNP-enabled system Suravee Suthikulpanit via iommu
2022-06-16 1:55 ` [PATCH v2 1/7] iommu/amd: Warn when found inconsistency EFR mask Suravee Suthikulpanit via iommu
2022-06-16 1:55 ` [PATCH v2 2/7] iommu/amd: Process all IVHDs before enabling IOMMU features Suravee Suthikulpanit via iommu
2022-06-16 1:55 ` [PATCH v2 3/7] iommu/amd: Introduce an iommu variable for tracking SNP support status Suravee Suthikulpanit via iommu
2022-06-16 1:55 ` [PATCH v2 4/7] iommu/amd: Introduce function to check and enable SNP Suravee Suthikulpanit via iommu
2022-06-22 7:55 ` Suthikulpanit, Suravee via iommu
2022-06-22 8:35 ` Robin Murphy
2022-06-22 11:00 ` Suthikulpanit, Suravee via iommu
2022-06-16 1:55 ` [PATCH v2 5/7] iommu/amd: Set translation valid bit only when IO page tables are in use Suravee Suthikulpanit via iommu
2022-06-16 1:55 ` [PATCH v2 6/7] iommu/amd: Do not support IOMMU_DOMAIN_IDENTITY after SNP is enabled Suravee Suthikulpanit via iommu
2022-06-22 8:39 ` Robin Murphy
2022-06-16 1:55 ` Suravee Suthikulpanit via iommu [this message]
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