[PATCH 4.19 38/78] iommu/amd: Do not use IOMMUv2 functionality when SME is active

Greg Kroah-Hartman
2020-09-16T00:18:21Z

From: Joerg Roedel <jroedel@suse.de>

[ 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>
---
drivers/iommu/amd_iommu_v2.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 58da65df03f5e..7a59a8ebac108 100644
--- 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;

--
2.25.1