[RFC, PATCHv1 17/28] x86/mm: define virtual memory map for 5-level paging
From: Kirill A. Shutemov
Date: Thu Dec 08 2016 - 11:28:06 EST
The first part of memory map (up to %esp fixup) simply scales existing
map for 4-level paging by factor of 9 -- number of bits addressed by
additional page table level.
The rest of the map is uncahnged.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
Documentation/x86/x86_64/mm.txt | 23 ++++++++++++++++++++++-
arch/x86/Kconfig | 1 +
arch/x86/include/asm/kasan.h | 9 ++++++---
arch/x86/include/asm/page_64_types.h | 10 ++++++++++
arch/x86/include/asm/pgtable_64_types.h | 6 ++++++
arch/x86/include/asm/sparsemem.h | 9 +++++++--
6 files changed, 52 insertions(+), 6 deletions(-)
diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
index 8c7dd5957ae1..d33fb0799b3d 100644
--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -12,7 +12,7 @@ ffffc90000000000 - ffffe8ffffffffff (=45 bits) vmalloc/ioremap space
ffffe90000000000 - ffffe9ffffffffff (=40 bits) hole
ffffea0000000000 - ffffeaffffffffff (=40 bits) virtual memory map (1TB)
... unused hole ...
-ffffec0000000000 - fffffc0000000000 (=44 bits) kasan shadow memory (16TB)
+ffffec0000000000 - fffffbffffffffff (=44 bits) kasan shadow memory (16TB)
... unused hole ...
ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
... unused hole ...
@@ -23,6 +23,27 @@ ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space
ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls
ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole
+Virtual memory map with 5 level page tables:
+
+0000000000000000 - 00ffffffffffffff (=56 bits) user space, different per mm
+hole caused by [57:63] 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
+ffd2000000000000 - ff93ffffffffffff (=49 bits) virtual memory map (512TB)
+... unused hole ...
+ff96000000000000 - ffb5ffffffffffff (=53 bits) kasan shadow memory (8PB)
+... unused hole ...
+fffe000000000000 - fffeffffffffffff (=49 bits) %esp fixup stacks
+... unused hole ...
+ffffffef00000000 - ffffffff00000000 (=64 GB) EFI region mapping space
+... unused hole ...
+ffffffff80000000 - ffffffffa0000000 (=512 MB) kernel text mapping, from phys 0
+ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space
+ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls
+ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole
+
The direct mapping covers all memory in the system up to the highest
memory address (this means in some cases it can also include PCI memory
holes).
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2a1f0ce7c59a..df4f1d514ab0 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -279,6 +279,7 @@ config ARCH_SUPPORTS_DEBUG_PAGEALLOC
config KASAN_SHADOW_OFFSET
hex
depends on KASAN
+ default 0xdfb6000000000000 if X86_5LEVEL
default 0xdffffc0000000000
config HAVE_INTEL_TXT
diff --git a/arch/x86/include/asm/kasan.h b/arch/x86/include/asm/kasan.h
index 1410b567ecde..2587c6bd89be 100644
--- a/arch/x86/include/asm/kasan.h
+++ b/arch/x86/include/asm/kasan.h
@@ -11,9 +11,12 @@
* 'kernel address space start' >> KASAN_SHADOW_SCALE_SHIFT
*/
#define KASAN_SHADOW_START (KASAN_SHADOW_OFFSET + \
- (0xffff800000000000ULL >> 3))
-/* 47 bits for kernel address -> (47 - 3) bits for shadow */
-#define KASAN_SHADOW_END (KASAN_SHADOW_START + (1ULL << (47 - 3)))
+ ((-1UL << __VIRTUAL_MASK_SHIFT) >> 3))
+/*
+ * 47 bits for kernel address -> (47 - 3) bits for shadow
+ * 56 bits for kernel address -> (56 - 3) bits fro shadow
+ */
+#define KASAN_SHADOW_END (KASAN_SHADOW_START + (1ULL << (__VIRTUAL_MASK_SHIFT - 3)))
#ifndef __ASSEMBLY__
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 9215e0527647..3f5f08b010d0 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -36,7 +36,12 @@
* hypervisor to fit. Choosing 16 slots here is arbitrary, but it's
* what Xen requires.
*/
+#ifdef CONFIG_X86_5LEVEL
+#define __PAGE_OFFSET_BASE _AC(0xff10000000000000, UL)
+#else
#define __PAGE_OFFSET_BASE _AC(0xffff880000000000, UL)
+#endif
+
#ifdef CONFIG_RANDOMIZE_MEMORY
#define __PAGE_OFFSET page_offset_base
#else
@@ -46,8 +51,13 @@
#define __START_KERNEL_map _AC(0xffffffff80000000, UL)
/* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
+#ifdef CONFIG_X86_5LEVEL
+#define __PHYSICAL_MASK_SHIFT 52
+#define __VIRTUAL_MASK_SHIFT 56
+#else
#define __PHYSICAL_MASK_SHIFT 46
#define __VIRTUAL_MASK_SHIFT 47
+#endif
/*
* Kernel image size is limited to 1GiB due to the fixmap living in the
diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
index d15ca53bd462..034cbca37c91 100644
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -56,9 +56,15 @@ 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 VMEMMAP_START _AC(0xffd2000000000000, UL)
+#else
#define VMALLOC_SIZE_TB _AC(32, UL)
#define __VMALLOC_BASE _AC(0xffffc90000000000, UL)
#define VMEMMAP_START _AC(0xffffea0000000000, UL)
+#endif
#ifdef CONFIG_RANDOMIZE_MEMORY
#define VMALLOC_START vmalloc_base
#else
diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h
index 4517d6b93188..1f5bee2c202f 100644
--- a/arch/x86/include/asm/sparsemem.h
+++ b/arch/x86/include/asm/sparsemem.h
@@ -26,8 +26,13 @@
# endif
#else /* CONFIG_X86_32 */
# define SECTION_SIZE_BITS 27 /* matt - 128 is convenient right now */
-# define MAX_PHYSADDR_BITS 44
-# define MAX_PHYSMEM_BITS 46
+# ifdef CONFIG_X86_5LEVEL
+# define MAX_PHYSADDR_BITS 52
+# define MAX_PHYSMEM_BITS 52
+# else
+# define MAX_PHYSADDR_BITS 44
+# define MAX_PHYSMEM_BITS 46
+# endif
#endif
#endif /* CONFIG_SPARSEMEM */
--
2.10.2