vm-layout.rst

  1.. SPDX-License-Identifier: GPL-2.0
  2.. include:: ../../disclaimer-zh_CN.rst
  3
  4:Original: Documentation/arch/riscv/vm-layout.rst
  5
  6:翻译:
  7
  8 司延腾 Yanteng Si <siyanteng@loongson.cn>
  9        Binbin Zhou <zhoubinbin@loongson.cn>
 10
 11============================
 12RISC-V Linux上的虚拟内存布局
 13============================
 14
 15:作者: Alexandre Ghiti <alex@ghiti.fr>
 16:日期: 12 February 2021
 17
 18这份文件描述了RISC-V Linux内核使用的虚拟内存布局。
 19
 2032位 RISC-V Linux 内核
 21======================
 22
 23RISC-V Linux Kernel SV32
 24------------------------
 25
 26TODO
 27
 2864位 RISC-V Linux 内核
 29======================
 30
 31RISC-V特权架构文档指出，64位地址 "必须使第63-48位值都等于第47位，否则将发生缺页异常。"：这将虚
 32拟地址空间分成两半，中间有一个非常大的洞，下半部分是用户空间所在的地方，上半部分是RISC-V Linux
 33内核所在的地方。
 34
 35RISC-V Linux Kernel SV39
 36------------------------
 37
 38::
 39
 40  ========================================================================================================================
 41      开始地址       |   偏移      |     结束地址      |  大小    | 虚拟内存区域描述
 42  ========================================================================================================================
 43                    |            |                  |         |
 44   0000000000000000 |    0       | 0000003fffffffff |  256 GB | 用户空间虚拟内存，每个内存管理器不同
 45  __________________|____________|__________________|_________|___________________________________________________________
 46                    |            |                  |         |
 47   0000004000000000 | +256    GB | ffffffbfffffffff | ~16M TB | ... 巨大的、几乎64位宽的直到内核映射的-256GB地方
 48                    |            |                  |         |     开始偏移的非经典虚拟内存地址空洞。
 49                    |            |                  |         |
 50  __________________|____________|__________________|_________|___________________________________________________________
 51                                                              |
 52                                                              | 内核空间的虚拟内存，在所有进程之间共享:
 53  ____________________________________________________________|___________________________________________________________
 54                    |            |                  |         |
 55   ffffffc6fee00000 | -228    GB | ffffffc6feffffff |    2 MB | fixmap
 56   ffffffc6ff000000 | -228    GB | ffffffc6ffffffff |   16 MB | PCI io
 57   ffffffc700000000 | -228    GB | ffffffc7ffffffff |    4 GB | vmemmap
 58   ffffffc800000000 | -224    GB | ffffffd7ffffffff |   64 GB | vmalloc/ioremap space
 59   ffffffd800000000 | -160    GB | fffffff6ffffffff |  124 GB | 直接映射所有物理内存
 60   fffffff700000000 |  -36    GB | fffffffeffffffff |   32 GB | kasan
 61  __________________|____________|__________________|_________|____________________________________________________________
 62                                                              |
 63                                                              |
 64  ____________________________________________________________|____________________________________________________________
 65                    |            |                  |         |
 66   ffffffff00000000 |   -4    GB | ffffffff7fffffff |    2 GB | modules, BPF
 67   ffffffff80000000 |   -2    GB | ffffffffffffffff |    2 GB | kernel
 68  __________________|____________|__________________|_________|____________________________________________________________
 69
 70
 71RISC-V Linux Kernel SV48
 72------------------------
 73
 74::
 75
 76 ========================================================================================================================
 77      开始地址       |   偏移      |     结束地址      |  大小    | 虚拟内存区域描述
 78 ========================================================================================================================
 79                    |            |                  |         |
 80   0000000000000000 |    0       | 00007fffffffffff |  128 TB | 用户空间虚拟内存，每个内存管理器不同
 81  __________________|____________|__________________|_________|___________________________________________________________
 82                    |            |                  |         |
 83   0000800000000000 | +128    TB | ffff7fffffffffff | ~16M TB | ... 巨大的、几乎64位宽的直到内核映射的-128TB地方
 84                    |            |                  |         |     开始偏移的非经典虚拟内存地址空洞。
 85                    |            |                  |         |
 86  __________________|____________|__________________|_________|___________________________________________________________
 87                                                              |
 88                                                              | 内核空间的虚拟内存，在所有进程之间共享:
 89  ____________________________________________________________|___________________________________________________________
 90                    |            |                  |         |
 91   ffff8d7ffee00000 |  -114.5 TB | ffff8d7ffeffffff |    2 MB | fixmap
 92   ffff8d7fff000000 |  -114.5 TB | ffff8d7fffffffff |   16 MB | PCI io
 93   ffff8d8000000000 |  -114.5 TB | ffff8f7fffffffff |    2 TB | vmemmap
 94   ffff8f8000000000 |  -112.5 TB | ffffaf7fffffffff |   32 TB | vmalloc/ioremap space
 95   ffffaf8000000000 |  -80.5  TB | ffffef7fffffffff |   64 TB | 直接映射所有物理内存
 96   ffffef8000000000 |  -16.5  TB | fffffffeffffffff | 16.5 TB | kasan
 97  __________________|____________|__________________|_________|____________________________________________________________
 98                                                              |
 99                                                              | 从此处开始，与39-bit布局相同：
100  ____________________________________________________________|____________________________________________________________
101                    |            |                  |         |
102   ffffffff00000000 |   -4    GB | ffffffff7fffffff |    2 GB | modules, BPF
103   ffffffff80000000 |   -2    GB | ffffffffffffffff |    2 GB | kernel
104  __________________|____________|__________________|_________|____________________________________________________________