From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Date: Wed, 13 Jul 2022 17:56:51 -0500
Subject: iommu/amd: Do not support IOMMUv2 APIs when SNP is enabled
Git-commit: 30315e71b42603307989d813a620781ff8238f3c
Patch-mainline: v6.0-rc1
References: bsc#1205701
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>
Link: https://lore.kernel.org/r/20220713225651.20758-10-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
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 538c750ceed6..d86496114ca5 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -3458,7 +3458,12 @@ __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);