[RFC PATCH v2 15/20] iommu/amd: AMD IOMMU support for memory encryption

From: Tom Lendacky
Date: Mon Aug 22 2016 - 18:54:30 EST


Add support to the AMD IOMMU driver to set the memory encryption mask if
memory encryption is enabled.

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
arch/x86/include/asm/mem_encrypt.h | 2 ++
arch/x86/mm/mem_encrypt.c | 5 +++++
drivers/iommu/amd_iommu.c | 10 ++++++++++
3 files changed, 17 insertions(+)

diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
index 384fdfb..e395729 100644
--- a/arch/x86/include/asm/mem_encrypt.h
+++ b/arch/x86/include/asm/mem_encrypt.h
@@ -36,6 +36,8 @@ void __init sme_early_init(void);
/* Architecture __weak replacement functions */
void __init mem_encrypt_init(void);

+unsigned long amd_iommu_get_me_mask(void);
+
unsigned long swiotlb_get_me_mask(void);
void swiotlb_set_mem_dec(void *vaddr, unsigned long size);

diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 6b2e8bf..2f28d87 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -185,6 +185,11 @@ void __init mem_encrypt_init(void)
swiotlb_clear_encryption();
}

+unsigned long amd_iommu_get_me_mask(void)
+{
+ return sme_me_mask;
+}
+
unsigned long swiotlb_get_me_mask(void)
{
return sme_me_mask;
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 96de97a..63995e3 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -166,6 +166,15 @@ struct dma_ops_domain {
static struct iova_domain reserved_iova_ranges;
static struct lock_class_key reserved_rbtree_key;

+/*
+ * Support for memory encryption. If memory encryption is supported, then an
+ * override to this function will be provided.
+ */
+unsigned long __weak amd_iommu_get_me_mask(void)
+{
+ return 0;
+}
+
/****************************************************************************
*
* Helper functions
@@ -2302,6 +2311,7 @@ static dma_addr_t __map_single(struct device *dev,

prot = dir2prot(direction);

+ paddr |= amd_iommu_get_me_mask();
start = address;
for (i = 0; i < pages; ++i) {
ret = iommu_map_page(&dma_dom->domain, start, paddr,