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 __________________|____________|__________________|_________|____________________________________________________________ 105