linux-kernel - [PATCH] iommu/amd: clear SME flag for mmio pages

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Message-ID: <20250625064802.3640589-1-east.moutain.yang@gmail.com>
Date: Wed, 25 Jun 2025 14:48:02 +0800
From: YangWencheng <east.moutain.yang@...il.com>
To: east.moutain.yang@...il.com
Cc: joro@...tes.org,
	suravee.suthikulpanit@....com,
	will@...nel.org,
	robin.murphy@....com,
	iommu@...ts.linux.dev,
	linux-kernel@...r.kernel.org
Subject: [PATCH] iommu/amd: clear SME flag for mmio pages

If paddr is a mmio address, clear the SME flag. It makes no sense to
set SME bit on MMIO address.
---
 drivers/iommu/amd/io_pgtable.c    | 6 ++++--
 drivers/iommu/amd/io_pgtable_v2.c | 6 +++++-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c
index 4d308c071134..88b204449c2c 100644
--- a/drivers/iommu/amd/io_pgtable.c
+++ b/drivers/iommu/amd/io_pgtable.c
@@ -352,15 +352,17 @@ static int iommu_v1_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
 			updated = true;
 
 		if (count > 1) {
-			__pte = PAGE_SIZE_PTE(__sme_set(paddr), pgsize);
+			__pte = PAGE_SIZE_PTE(paddr, pgsize);
 			__pte |= PM_LEVEL_ENC(7) | IOMMU_PTE_PR | IOMMU_PTE_FC;
 		} else
-			__pte = __sme_set(paddr) | IOMMU_PTE_PR | IOMMU_PTE_FC;
+			__pte = paddr | IOMMU_PTE_PR | IOMMU_PTE_FC;
 
 		if (prot & IOMMU_PROT_IR)
 			__pte |= IOMMU_PTE_IR;
 		if (prot & IOMMU_PROT_IW)
 			__pte |= IOMMU_PTE_IW;
+		if (pfn_valid(__phys_to_pfn(paddr)))
+			__pte = __sme_set(__pte);
 
 		for (i = 0; i < count; ++i)
 			pte[i] = __pte;
diff --git a/drivers/iommu/amd/io_pgtable_v2.c b/drivers/iommu/amd/io_pgtable_v2.c
index b47941353ccb..b301fb8e58fa 100644
--- a/drivers/iommu/amd/io_pgtable_v2.c
+++ b/drivers/iommu/amd/io_pgtable_v2.c
@@ -65,7 +65,11 @@ static u64 set_pte_attr(u64 paddr, u64 pg_size, int prot)
 {
 	u64 pte;
 
-	pte = __sme_set(paddr & PM_ADDR_MASK);
+	if (pfn_valid(__phys_to_pfn(paddr)))
+		pte = __sme_set(paddr & PM_ADDR_MASK);
+	else
+		pte = paddr & PM_ADDR_MASK;
+
 	pte |= IOMMU_PAGE_PRESENT | IOMMU_PAGE_USER;
 	pte |= IOMMU_PAGE_ACCESS | IOMMU_PAGE_DIRTY;
 
-- 
2.43.0