path: root/Documentation/x86/x86_64
diff options
authorDave Hansen <dave.hansen@linux.intel.com>2014-09-18 12:56:06 -0700
committerIngo Molnar <mingo@kernel.org>2014-09-19 12:48:02 +0200
commitbeb9147e95a75f41c984d7235cf6d59f3ca2d5db (patch)
treed1cc1f24978e29bb2c51149cfe8cc6a6df854971 /Documentation/x86/x86_64
parent84779575554e2a19b9f6fc8d44f9763546a822ad (diff)
x86/mm: Update memory map description to list hypervisor-reserved area
Peter Anvin says: > 0xffff880000000000 is the lowest usable address because we have > agreed to leave 0xffff800000000000-0xffff880000000000 for the > hypervisor or other non-OS uses. Let's call this out in the documentation. This came up during the kernel address sanitizer discussions where it was proposed to use this area for other kernel things. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Link: http://lkml.kernel.org/r/20140918195606.841389D2@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation/x86/x86_64')
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
index afe68ddbe6a4..052ee643a32e 100644
--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -5,7 +5,7 @@ Virtual memory map with 4 level page tables:
0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm
hole caused by [48:63] sign extension
-ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole
+ffff800000000000 - ffff87ffffffffff (=43 bits) guard hole, reserved for hypervisor
ffff880000000000 - ffffc7ffffffffff (=64 TB) direct mapping of all phys. memory
ffffc80000000000 - ffffc8ffffffffff (=40 bits) hole
ffffc90000000000 - ffffe8ffffffffff (=45 bits) vmalloc/ioremap space

Privacy Policy