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From:   Arvind Sankar <nivedita@alum.mit.edu>
To:     Tom Lendacky <thomas.lendacky@amd.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>
Cc:     x86@kernel.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org
Subject: [PATCH 1/2] x86/mm/sme: Fix definition of PMD_FLAGS_DEC_WP
Date:   Wed, 11 Nov 2020 11:09:45 -0500
Message-Id: <20201111160946.147341-1-nivedita@alum.mit.edu>
In-Reply-To: <13073a85-24c1-6efa-578b-54218d21f49d@amd.com>
References: <13073a85-24c1-6efa-578b-54218d21f49d@amd.com>
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The PAT bit is in different locations for 4k and 2M/1G page table
entries.

Add a definition for _PAGE_LARGE_CACHE_MASK to represent the three
caching bits (PWT, PCD, PAT), similar to _PAGE_CACHE_MASK for 4k pages,
and use it in the definition of PMD_FLAGS_DEC_WP to get the correct PAT
index for write-protected pages.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Fixes: 6ebcb060713f ("x86/mm: Add support to encrypt the kernel in-place")
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
---
 arch/x86/include/asm/pgtable_types.h | 1 +
 arch/x86/mm/mem_encrypt_identity.c   | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 816b31c68550..394757ee030a 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -155,6 +155,7 @@ enum page_cache_mode {
 #define _PAGE_ENC		(_AT(pteval_t, sme_me_mask))
 
 #define _PAGE_CACHE_MASK	(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)
+#define _PAGE_LARGE_CACHE_MASK	(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT_LARGE)
 
 #define _PAGE_NOCACHE		(cachemode2protval(_PAGE_CACHE_MODE_UC))
 #define _PAGE_CACHE_WP		(cachemode2protval(_PAGE_CACHE_MODE_WP))
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index 733b983f3a89..6c5eb6f3f14f 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -45,8 +45,8 @@
 #define PMD_FLAGS_LARGE		(__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
 
 #define PMD_FLAGS_DEC		PMD_FLAGS_LARGE
-#define PMD_FLAGS_DEC_WP	((PMD_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
-				 (_PAGE_PAT | _PAGE_PWT))
+#define PMD_FLAGS_DEC_WP	((PMD_FLAGS_DEC & ~_PAGE_LARGE_CACHE_MASK) | \
+				 (_PAGE_PAT_LARGE | _PAGE_PWT))
 
 #define PMD_FLAGS_ENC		(PMD_FLAGS_LARGE | _PAGE_ENC)
 
-- 
2.26.2