[patch V163 38/51] x86/mm/64: Make a full PGD-entry size hole in the memory map

[Thomas Gleixner]

From: Andy Lutomirski <luto@xxxxxxxxxx>

Shrink vmalloc space from 16384TiB to 12800TiB to enlarge the hole starting
at 0xff90000000000000 to be a full PGD entry.

A subsequent patch will use this hole for the pagetable isolation LDT
alias.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: David Laight <David.Laight@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx>

---
 Documentation/x86/x86_64/mm.txt         |    4 ++--
 arch/x86/include/asm/pgtable_64_types.h |    4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -28,8 +28,8 @@ ffffffffffe00000 - ffffffffffffffff (=2
 hole caused by [56:63] sign extension
 ff00000000000000 - ff0fffffffffffff (=52 bits) guard hole, reserved for hypervisor
 ff10000000000000 - ff8fffffffffffff (=55 bits) direct mapping of all phys. memory
-ff90000000000000 - ff91ffffffffffff (=49 bits) hole
-ff92000000000000 - ffd1ffffffffffff (=54 bits) vmalloc/ioremap space
+ff90000000000000 - ff9fffffffffffff (=52 bits) hole
+ffa0000000000000 - ffd1ffffffffffff (=54 bits) vmalloc/ioremap space (12800 TB)
 ffd2000000000000 - ffd3ffffffffffff (=49 bits) hole
 ffd4000000000000 - ffd5ffffffffffff (=49 bits) virtual memory map (512TB)
 ... unused hole ...
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -78,8 +78,8 @@ typedef struct { pteval_t pte; } pte_t;
 /* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
 #define MAXMEM		_AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)
 #ifdef CONFIG_X86_5LEVEL
-#define VMALLOC_SIZE_TB _AC(16384, UL)
-#define __VMALLOC_BASE	_AC(0xff92000000000000, UL)
+#define VMALLOC_SIZE_TB _AC(12800, UL)
+#define __VMALLOC_BASE	_AC(0xffa0000000000000, UL)
 #define __VMEMMAP_BASE	_AC(0xffd4000000000000, UL)
 #else
 #define VMALLOC_SIZE_TB	_AC(32, UL)