iommu/amd: Do not use IOMMUv2 functionality when SME is active

[ Upstream commit 2822e582501b65707089b097e773e6fd70774841 ]

When memory encryption is active the device is likely not in a direct
mapped domain. Forbid using IOMMUv2 functionality for now until finer
grained checks for this have been implemented.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200824105415.21000-3-joro@8bytes.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 58da65df03f5e2551352c9d99c42a794d036b8e5..7a59a8ebac1089bf40138bacc460815c7d3a9be5 100644 (file)
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -776,6 +776,13 @@ int amd_iommu_init_device(struct pci_dev *pdev, int pasids)
 
        might_sleep();
 
+       /*
+        * When memory encryption is active the device is likely not in a
+        * direct-mapped domain. Forbid using IOMMUv2 functionality for now.
+        */
+       if (mem_encrypt_active())
+               return -ENODEV;
+
        if (!amd_iommu_v2_supported())
                return -ENODEV;