Re: [PATCH] x86/mm: Fix PAGE_KERNEL_IO removal breakage
From: Lucas De Marchi
Date: Thu Dec 02 2021 - 10:55:43 EST
On Thu, Dec 02, 2021 at 03:46:46PM +0100, Joerg Roedel wrote:
From: Joerg Roedel <jroedel@xxxxxxx>
The removal of PAGE_KERNEL_IO broke SEV-ES because it changed the
mapping of ioremap and some fixmap areas (like the local APIC page)
from unencrypted to encrypted. Change those mappings back to
be unencrypted.
Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Fixes: 27dff0f58bde ("x86/mm: Nuke PAGE_KERNEL_IO")
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
oops, missed the fact PAGE_KERNEL had `| ENC` while PAGE_KERENL_IO
didn't have it. Thanks for the fixup.
Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Lucas De Marchi
---
arch/x86/include/asm/fixmap.h | 2 +-
arch/x86/include/asm/pgtable_types.h | 21 +++++++++++----------
arch/x86/mm/ioremap.c | 2 +-
3 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index 5e186a69db10..a2eaf265f784 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -173,7 +173,7 @@ static inline void __set_fixmap(enum fixed_addresses idx,
* supported for MMIO addresses, so make sure that the memory encryption
* mask is not part of the page attributes.
*/
-#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE
+#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE_NOENC
/*
* Early memremap routines used for in-place encryption. The mappings created
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index a87224767ff3..fc9b6995cb22 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -208,16 +208,17 @@ enum page_cache_mode {
#define __pgprot_mask(x) __pgprot((x) & __default_kernel_pte_mask)
-#define PAGE_KERNEL __pgprot_mask(__PAGE_KERNEL | _ENC)
-#define PAGE_KERNEL_NOENC __pgprot_mask(__PAGE_KERNEL | 0)
-#define PAGE_KERNEL_RO __pgprot_mask(__PAGE_KERNEL_RO | _ENC)
-#define PAGE_KERNEL_EXEC __pgprot_mask(__PAGE_KERNEL_EXEC | _ENC)
-#define PAGE_KERNEL_EXEC_NOENC __pgprot_mask(__PAGE_KERNEL_EXEC | 0)
-#define PAGE_KERNEL_ROX __pgprot_mask(__PAGE_KERNEL_ROX | _ENC)
-#define PAGE_KERNEL_NOCACHE __pgprot_mask(__PAGE_KERNEL_NOCACHE | _ENC)
-#define PAGE_KERNEL_LARGE __pgprot_mask(__PAGE_KERNEL_LARGE | _ENC)
-#define PAGE_KERNEL_LARGE_EXEC __pgprot_mask(__PAGE_KERNEL_LARGE_EXEC | _ENC)
-#define PAGE_KERNEL_VVAR __pgprot_mask(__PAGE_KERNEL_VVAR | _ENC)
+#define PAGE_KERNEL __pgprot_mask(__PAGE_KERNEL | _ENC)
+#define PAGE_KERNEL_NOENC __pgprot_mask(__PAGE_KERNEL | 0)
+#define PAGE_KERNEL_RO __pgprot_mask(__PAGE_KERNEL_RO | _ENC)
+#define PAGE_KERNEL_EXEC __pgprot_mask(__PAGE_KERNEL_EXEC | _ENC)
+#define PAGE_KERNEL_EXEC_NOENC __pgprot_mask(__PAGE_KERNEL_EXEC | 0)
+#define PAGE_KERNEL_ROX __pgprot_mask(__PAGE_KERNEL_ROX | _ENC)
+#define PAGE_KERNEL_NOCACHE __pgprot_mask(__PAGE_KERNEL_NOCACHE | _ENC)
+#define PAGE_KERNEL_NOCACHE_NOENC __pgprot_mask(__PAGE_KERNEL_NOCACHE | 0)
+#define PAGE_KERNEL_LARGE __pgprot_mask(__PAGE_KERNEL_LARGE | _ENC)
+#define PAGE_KERNEL_LARGE_EXEC __pgprot_mask(__PAGE_KERNEL_LARGE_EXEC | _ENC)
+#define PAGE_KERNEL_VVAR __pgprot_mask(__PAGE_KERNEL_VVAR | _ENC)
#endif /* __ASSEMBLY__ */
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 3102dda4b152..4fe8d43d53bb 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -243,7 +243,7 @@ __ioremap_caller(resource_size_t phys_addr, unsigned long size,
* make sure the memory encryption attribute is enabled in the
* resulting mapping.
*/
- prot = PAGE_KERNEL;
+ prot = PAGE_KERNEL_NOENC;
if ((io_desc.flags & IORES_MAP_ENCRYPTED) || encrypted)
prot = pgprot_encrypted(prot);
--
2.34.0