From 5b12904065798fee8b153a506ac7b72d5ebbe26c Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Sat, 6 Oct 2018 16:43:26 +0800 Subject: [PATCH] x86/mm/doc: Clean up the x86-64 virtual memory layout descriptions In Documentation/x86/x86_64/mm.txt, the description of the x86-64 virtual memory layout has become a confusing hodgepodge of inconsistencies: - there's a hard to read mixture of 'TB' and 'bits' notation - the entries sometimes mention a size in the description and sometimes not - sometimes they list holes by address, sometimes only as an 'unused hole' line So make it all a coherent, readable, well organized description. Signed-off-by: Baoquan He Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: corbet@lwn.net Cc: linux-doc@vger.kernel.org Cc: thgarnie@google.com Link: http://lkml.kernel.org/r/20181006084327.27467-3-bhe@redhat.com Signed-off-by: Ingo Molnar --- Documentation/x86/x86_64/mm.txt | 84 ++++++++++++++++----------------- 1 file changed, 42 insertions(+), 42 deletions(-) diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt index 5432a96d31ff..b4bc95c9790e 100644 --- a/Documentation/x86/x86_64/mm.txt +++ b/Documentation/x86/x86_64/mm.txt @@ -1,55 +1,55 @@ Virtual memory map with 4 level page tables: -0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm -hole caused by [47:63] sign extension -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 -ffffe90000000000 - ffffe9ffffffffff (=40 bits) hole -ffffea0000000000 - ffffeaffffffffff (=40 bits) virtual memory map (1TB) -... unused hole ... -ffffec0000000000 - fffffbffffffffff (=44 bits) kasan shadow memory (16TB) -... unused hole ... +0000000000000000 - 00007fffffffffff (=47 bits, 128 TB) user space, different per mm + hole caused by [47:63] sign extension +ffff800000000000 - ffff87ffffffffff (=43 bits, 8 TB) guard hole, reserved for hypervisor +ffff880000000000 - ffffc7ffffffffff (=46 bits, 64 TB) direct mapping of all phys. memory (page_offset_base) +ffffc80000000000 - ffffc8ffffffffff (=40 bits, 1 TB) unused hole +ffffc90000000000 - ffffe8ffffffffff (=45 bits, 32 TB) vmalloc/ioremap space (vmalloc_base) +ffffe90000000000 - ffffe9ffffffffff (=40 bits, 1 TB) unused hole +ffffea0000000000 - ffffeaffffffffff (=40 bits, 1 TB) virtual memory map (vmemmap_base) +ffffeb0000000000 - ffffebffffffffff (=40 bits, 1 TB) unused hole +ffffec0000000000 - fffffbffffffffff (=44 bits, 16 TB) kasan shadow memory +fffffc0000000000 - fffffdffffffffff (=41 bits, 2 TB) unused hole vaddr_end for KASLR -fffffe0000000000 - fffffe7fffffffff (=39 bits) cpu_entry_area mapping -fffffe8000000000 - fffffeffffffffff (=39 bits) LDT remap for PTI -ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks -... unused hole ... -ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space -... unused hole ... -ffffffff80000000 - ffffffff9fffffff (=512 MB) kernel text mapping, from phys 0 -ffffffffa0000000 - fffffffffeffffff (1520 MB) module mapping space +fffffe0000000000 - fffffe7fffffffff (=39 bits, 512 GB) cpu_entry_area mapping +fffffe8000000000 - fffffeffffffffff (=39 bits, 512 GB) LDT remap for PTI +ffffff0000000000 - ffffff7fffffffff (=39 bits, 512 GB) %esp fixup stacks +ffffff8000000000 - fffffffeefffffff (~39 bits, ~507 GB) unused hole +ffffffef00000000 - fffffffeffffffff (=36 bits, 64 GB) EFI region mapping space +ffffffff00000000 - ffffffff7fffffff (=31 bits, 2 GB) unused hole +ffffffff80000000 - ffffffff9fffffff (=29 bits, 512 MB) kernel text mapping, from phys 0 +ffffffffa0000000 - fffffffffeffffff (~31 bits, 1520 MB) module mapping space [fixmap start] - ffffffffff5fffff kernel-internal fixmap range -ffffffffff600000 - ffffffffff600fff (=4 kB) legacy vsyscall ABI -ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole +ffffffffff600000 - ffffffffff600fff ( =4 kB) legacy vsyscall ABI +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 [56:63] sign extension -ff00000000000000 - ff0fffffffffffff (=52 bits) guard hole, reserved for hypervisor -ff10000000000000 - ff8fffffffffffff (=55 bits) direct mapping of all phys. memory -ff90000000000000 - ff9fffffffffffff (=52 bits) LDT remap for PTI -ffa0000000000000 - ffd1ffffffffffff (=54 bits) vmalloc/ioremap space (12800 TB) -ffd2000000000000 - ffd3ffffffffffff (=49 bits) hole -ffd4000000000000 - ffd5ffffffffffff (=49 bits) virtual memory map (512TB) -... unused hole ... -ffdf000000000000 - fffffc0000000000 (=53 bits) kasan shadow memory (8PB) -... unused hole ... +0000000000000000 - 00ffffffffffffff (=56 bits, 64 PB) user space, different per mm + hole caused by [56:63] sign extension +ff00000000000000 - ff0fffffffffffff (=52 bits, 4 PB) guard hole, reserved for hypervisor +ff10000000000000 - ff8fffffffffffff (=55 bits, 32 PB) direct mapping of all phys. memory (page_offset_base) +ff90000000000000 - ff9fffffffffffff (=52 bits, 4 PB) LDT remap for PTI +ffa0000000000000 - ffd1ffffffffffff (=53 bits, 12800 TB) vmalloc/ioremap space (vmalloc_base) +ffd2000000000000 - ffd3ffffffffffff (=49 bits, 512 TB) unused hole +ffd4000000000000 - ffd5ffffffffffff (=49 bits, 512 TB) virtual memory map (vmemmap_base) +ffd6000000000000 - ffdeffffffffffff (~51 bits, 2304 TB) unused hole +ffdf000000000000 - fffffdffffffffff (~53 bits, ~8 PB) kasan shadow memory +fffffc0000000000 - fffffdffffffffff (=41 bits, 2 TB) unused hole vaddr_end for KASLR -fffffe0000000000 - fffffe7fffffffff (=39 bits) cpu_entry_area mapping -... unused hole ... -ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks -... unused hole ... -ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space -... unused hole ... -ffffffff80000000 - ffffffff9fffffff (=512 MB) kernel text mapping, from phys 0 -ffffffffa0000000 - fffffffffeffffff (1520 MB) module mapping space +fffffe0000000000 - fffffe7fffffffff (=39 bits, 512 GB) cpu_entry_area mapping +fffffe8000000000 - fffffeffffffffff (=39 bits, 512 GB) unused hole +ffffff0000000000 - ffffff7fffffffff (=39 bits, 512 GB) %esp fixup stacks +ffffff8000000000 - ffffffeeffffffff (~39 bits, 444 GB) unused hole +ffffffef00000000 - fffffffeffffffff (=36 bits, 64 GB) EFI region mapping space +ffffffff00000000 - ffffffff7fffffff (31 bits, 2 GB) unused hole +ffffffff80000000 - ffffffff9fffffff (=29 bits, 512 MB) kernel text mapping, from phys 0 +ffffffffa0000000 - fffffffffeffffff (~31 bits, 1520 MB) module mapping space [fixmap start] - ffffffffff5fffff kernel-internal fixmap range -ffffffffff600000 - ffffffffff600fff (=4 kB) legacy vsyscall ABI -ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole +ffffffffff600000 - ffffffffff600fff ( =4 kB) legacy vsyscall ABI +ffffffffffe00000 - ffffffffffffffff ( =2 MB) unused hole Architecture defines a 64-bit virtual address. Implementations can support less. Currently supported are 48- and 57-bit virtual addresses. Bits 63 -- 2.20.1