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

[Tom Lendacky]

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,