Documentation/translations/zh_CN/riscv/vm-layout.rst

   1 .. SPDX-License-Identifier: GPL-2.0
   2 .. include:: ../disclaimer-zh_CN.rst
   3
   4 :Original: Documentation/riscv/vm-layout.rst
   5
   6 :翻译:
   7
   8  司延腾 Yanteng Si <siyanteng@loongson.cn>
   9
  10 ============================
  11 RISC-V Linux上的虚拟内存布局
  12 ============================
  13
  14 :作者: Alexandre Ghiti <alex@ghiti.fr>
  15 :日期: 12 February 2021
  16
  17 这份文件描述了RISC-V Linux内核使用的虚拟内存布局。
  18
  19 32位 RISC-V Linux 内核
  20 ======================
  21
  22 RISC-V Linux Kernel SV32
  23 ------------------------
  24
  25 TODO
  26
  27 64位 RISC-V Linux 内核
  28 ======================
  29
  30 RISC-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
  31 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
  32 内核所在的地方。
  33
  34 RISC-V Linux Kernel SV39
  35 ------------------------
  36
  37 ::
  38
  39   ========================================================================================================================
  40       开始地址       |   偏移      |     结束地址      |  大小    | 虚拟内存区域描述
  41   ========================================================================================================================
  42                     |            |                  |         |
  43    0000000000000000 |    0       | 0000003fffffffff |  256 GB | 用户空间虚拟内存，每个内存管理器不同
  44   __________________|____________|__________________|_________|___________________________________________________________
  45                     |            |                  |         |
  46    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
  47                     |            |                  |         |     开始偏移的非经典虚拟内存地址空洞。
  48                     |            |                  |         |
  49   __________________|____________|__________________|_________|___________________________________________________________
  50                                                               |
  51                                                               | 内核空间的虚拟内存，在所有进程之间共享:
  52   ____________________________________________________________|___________________________________________________________
  53                     |            |                  |         |
  54    ffffffc6fee00000 | -228    GB | ffffffc6feffffff |    2 MB | fixmap
  55    ffffffc6ff000000 | -228    GB | ffffffc6ffffffff |   16 MB | PCI io
  56    ffffffc700000000 | -228    GB | ffffffc7ffffffff |    4 GB | vmemmap
  57    ffffffc800000000 | -224    GB | ffffffd7ffffffff |   64 GB | vmalloc/ioremap space
  58    ffffffd800000000 | -160    GB | fffffff6ffffffff |  124 GB | 直接映射所有物理内存
  59    fffffff700000000 |  -36    GB | fffffffeffffffff |   32 GB | kasan
  60   __________________|____________|__________________|_________|____________________________________________________________
  61                                                               |
  62                                                               |
  63   ____________________________________________________________|____________________________________________________________
  64                     |            |                  |         |
  65    ffffffff00000000 |   -4    GB | ffffffff7fffffff |    2 GB | modules, BPF
  66    ffffffff80000000 |   -2    GB | ffffffffffffffff |    2 GB | kernel
  67   __________________|____________|__________________|_________|____________________________________________________________