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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2024-04-24 11:20:35 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-05-02 17:29:30 +0300
commita8e8c79ed2eb195e04b8119b7d83c4ddcccf9739 (patch)
tree3372c0120879f3d89cc9b8e36bde3a5c1b6b17a6
parent2bd852307fdcefe474ff59730aec3f397f1585ae (diff)
downloadlinux-a8e8c79ed2eb195e04b8119b7d83c4ddcccf9739.tar.xz
x86/tdx: Preserve shared bit on mprotect()
commit a0a8d15a798be4b8f20aca2ba91bf6b688c6a640 upstream. The TDX guest platform takes one bit from the physical address to indicate if the page is shared (accessible by VMM). This bit is not part of the physical_mask and is not preserved during mprotect(). As a result, the 'shared' bit is lost during mprotect() on shared mappings. _COMMON_PAGE_CHG_MASK specifies which PTE bits need to be preserved during modification. AMD includes 'sme_me_mask' in the define to preserve the 'encrypt' bit. To cover both Intel and AMD cases, include 'cc_mask' in _COMMON_PAGE_CHG_MASK instead of 'sme_me_mask'. Reported-and-tested-by: Chris Oo <cho@microsoft.com> Fixes: 41394e33f3a0 ("x86/tdx: Extend the confidential computing API to support TDX guests") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20240424082035.4092071-1-kirill.shutemov%40linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/x86/include/asm/coco.h5
-rw-r--r--arch/x86/include/asm/pgtable_types.h3
2 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/include/asm/coco.h b/arch/x86/include/asm/coco.h
index 1f97d00ad858..100a752c33bb 100644
--- a/arch/x86/include/asm/coco.h
+++ b/arch/x86/include/asm/coco.h
@@ -13,9 +13,10 @@ enum cc_vendor {
};
extern enum cc_vendor cc_vendor;
-extern u64 cc_mask;
#ifdef CONFIG_ARCH_HAS_CC_PLATFORM
+extern u64 cc_mask;
+
static inline void cc_set_mask(u64 mask)
{
RIP_REL_REF(cc_mask) = mask;
@@ -25,6 +26,8 @@ u64 cc_mkenc(u64 val);
u64 cc_mkdec(u64 val);
void cc_random_init(void);
#else
+static const u64 cc_mask = 0;
+
static inline u64 cc_mkenc(u64 val)
{
return val;
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index f6116b66f289..f0b9b37c4609 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -127,7 +127,7 @@
*/
#define _COMMON_PAGE_CHG_MASK (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT | \
_PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY |\
- _PAGE_SOFT_DIRTY | _PAGE_DEVMAP | _PAGE_ENC | \
+ _PAGE_SOFT_DIRTY | _PAGE_DEVMAP | _PAGE_CC | \
_PAGE_UFFD_WP)
#define _PAGE_CHG_MASK (_COMMON_PAGE_CHG_MASK | _PAGE_PAT)
#define _HPAGE_CHG_MASK (_COMMON_PAGE_CHG_MASK | _PAGE_PSE | _PAGE_PAT_LARGE)
@@ -153,6 +153,7 @@ enum page_cache_mode {
};
#endif
+#define _PAGE_CC (_AT(pteval_t, cc_mask))
#define _PAGE_ENC (_AT(pteval_t, sme_me_mask))
#define _PAGE_CACHE_MASK (_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)