[PATCH v5 24/32] iommu/amd: Disable AMD IOMMU if memory encryption is active

Tom Lendacky
2017-04-18T21:21:00Z

For now, disable the AMD IOMMU if memory encryption is active. A future
patch will re-enable the function with full memory encryption support.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
drivers/iommu/amd_iommu_init.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 5a11328..c72d13b 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -29,6 +29,7 @@
#include <linux/export.h>
#include <linux/iommu.h>
#include <linux/kmemleak.h>
+#include <linux/mem_encrypt.h>
#include <asm/pci-direct.h>
#include <asm/iommu.h>
#include <asm/gart.h>
@@ -2552,6 +2553,12 @@ int __init amd_iommu_detect(void)
if (amd_iommu_disabled)
return -ENODEV;

+ /* For now, disable the IOMMU if SME is active */
+ if (sme_active()) {
+ pr_notice("AMD-Vi: SME is active, disabling the IOMMU\n");
+ return -ENODEV;
+ }
+
ret = iommu_go_to_state(IOMMU_IVRS_DETECTED);
if (ret)
return ret;