[RFC PATCH v1 13/28] iommu/amd: AMD IOMMU support for SEV

From: Brijesh Singh
Date: Mon Aug 22 2016 - 19:58:14 EST


From: Tom Lendacky <thomas.lendacky@xxxxxxx>

DMA must be performed to memory that is not mapped encrypted when running
with SEV active. So if SEV is active, do not return the encryption mask
to the IOMMU.

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
arch/x86/mm/mem_encrypt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index ce6e3ea..d6e9f96 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -237,7 +237,7 @@ void __init mem_encrypt_init(void)

unsigned long amd_iommu_get_me_mask(void)
{
- return sme_me_mask;
+ return sev_active ? 0 : sme_me_mask;
}

unsigned long swiotlb_get_me_mask(void)