tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1# SPDX-License-Identifier: GPL-2.0
2
3menu "UML-specific options"
4
5config UML
6 bool
7 default y
8 select ARCH_HAS_CPU_FINALIZE_INIT
9 select ARCH_HAS_FORTIFY_SOURCE
10 select ARCH_HAS_GCOV_PROFILE_ALL
11 select ARCH_HAS_KCOV
12 select ARCH_HAS_STRNCPY_FROM_USER
13 select ARCH_HAS_STRNLEN_USER
14 select ARCH_NO_PREEMPT
15 select HAVE_ARCH_AUDITSYSCALL
16 select HAVE_ARCH_KASAN if X86_64
17 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
18 select HAVE_ARCH_SECCOMP_FILTER
19 select HAVE_ASM_MODVERSIONS
20 select HAVE_UID16
21 select HAVE_DEBUG_KMEMLEAK
22 select HAVE_DEBUG_BUGVERBOSE
23 select HAVE_PAGE_SIZE_4KB
24 select NO_DMA if !UML_DMA_EMULATION
25 select OF_EARLY_FLATTREE if OF
26 select GENERIC_IRQ_SHOW
27 select GENERIC_CPU_DEVICES
28 select HAVE_GCC_PLUGINS
29 select ARCH_SUPPORTS_LTO_CLANG
30 select ARCH_SUPPORTS_LTO_CLANG_THIN
31 select TRACE_IRQFLAGS_SUPPORT
32 select TTY # Needed for line.c
33 select HAVE_ARCH_VMAP_STACK
34 select HAVE_RUST if X86_64
35
36config MMU
37 bool
38 default y
39
40config UML_DMA_EMULATION
41 bool
42
43config NO_IOMEM
44 bool "disable IOMEM" if EXPERT
45 depends on !INDIRECT_IOMEM
46 default y
47
48config UML_IOMEM_EMULATION
49 bool
50 select INDIRECT_IOMEM
51 select GENERIC_PCI_IOMAP
52 select GENERIC_IOMAP
53 select NO_GENERIC_PCI_IOPORT_MAP
54
55config NO_IOPORT_MAP
56 def_bool y
57
58config ISA
59 bool
60
61config SBUS
62 bool
63
64config LOCKDEP_SUPPORT
65 bool
66 default y
67
68config STACKTRACE_SUPPORT
69 bool
70 default y
71 select STACKTRACE
72
73config GENERIC_CALIBRATE_DELAY
74 bool
75 default y
76
77config HZ
78 int
79 default 100
80
81config NR_CPUS
82 int
83 range 1 1
84 default 1
85
86config ARCH_HAS_CACHE_LINE_SIZE
87 def_bool y
88
89source "arch/$(HEADER_ARCH)/um/Kconfig"
90
91config MAY_HAVE_RUNTIME_DEPS
92 bool
93
94config STATIC_LINK
95 bool "Force a static link"
96 depends on CC_CAN_LINK_STATIC_NO_RUNTIME_DEPS || !MAY_HAVE_RUNTIME_DEPS
97 help
98 This option gives you the ability to force a static link of UML.
99 Normally, UML is linked as a shared binary. This is inconvenient for
100 use in a chroot jail. So, if you intend to run UML inside a chroot,
101 you probably want to say Y here.
102 Additionally, this option enables using higher memory spaces (up to
103 2.75G) for UML.
104
105 NOTE: This option is incompatible with some networking features which
106 depend on features that require being dynamically loaded (like NSS).
107
108config LD_SCRIPT_STATIC
109 bool
110 default y
111 depends on STATIC_LINK
112
113config LD_SCRIPT_DYN
114 bool
115 default y
116 depends on !LD_SCRIPT_STATIC
117
118config LD_SCRIPT_DYN_RPATH
119 bool "set rpath in the binary" if EXPERT
120 default y
121 depends on LD_SCRIPT_DYN
122 help
123 Add /lib (and /lib64 for 64-bit) to the linux binary's rpath
124 explicitly.
125
126 You may need to turn this off if compiling for nix systems
127 that have their libraries in random /nix directories and
128 might otherwise unexpected use libraries from /lib or /lib64
129 instead of the desired ones.
130
131config HOSTFS
132 tristate "Host filesystem"
133 help
134 While the User-Mode Linux port uses its own root file system for
135 booting and normal file access, this module lets the UML user
136 access files stored on the host. It does not require any
137 network connection between the Host and UML. An example use of
138 this might be:
139
140 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
141
142 where /tmp/fromhost is an empty directory inside UML and
143 /tmp/umlshare is a directory on the host with files the UML user
144 wishes to access.
145
146 For more information, see
147 <http://user-mode-linux.sourceforge.net/hostfs.html>.
148
149 If you'd like to be able to work with files stored on the host,
150 say Y or M here; otherwise say N.
151
152config MCONSOLE
153 bool "Management console"
154 depends on PROC_FS
155 default y
156 help
157 The user mode linux management console is a low-level interface to
158 the kernel, somewhat like the i386 SysRq interface. Since there is
159 a full-blown operating system running under every user mode linux
160 instance, there is much greater flexibility possible than with the
161 SysRq mechanism.
162
163 If you answer 'Y' to this option, to use this feature, you need the
164 mconsole client (called uml_mconsole) which is present in CVS in
165 2.4.5-9um and later (path /tools/mconsole), and is also in the
166 distribution RPM package in 2.4.6 and later.
167
168 It is safe to say 'Y' here.
169
170config MAGIC_SYSRQ
171 bool "Magic SysRq key"
172 depends on MCONSOLE
173 help
174 If you say Y here, you will have some control over the system even
175 if the system crashes for example during kernel debugging (e.g., you
176 will be able to flush the buffer cache to disk, reboot the system
177 immediately or dump some status information). A key for each of the
178 possible requests is provided.
179
180 This is the feature normally accomplished by pressing a key
181 while holding SysRq (Alt+PrintScreen).
182
183 On UML, this is accomplished by sending a "sysrq" command with
184 mconsole, followed by the letter for the requested command.
185
186 The keys are documented in <file:Documentation/admin-guide/sysrq.rst>. Don't say Y
187 unless you really know what this hack does.
188
189config KERNEL_STACK_ORDER
190 int "Kernel stack size order"
191 default 2 if 64BIT
192 range 2 10 if 64BIT
193 default 1 if !64BIT
194 help
195 This option determines the size of UML kernel stacks. They will
196 be 1 << order pages. The default is OK unless you're running Valgrind
197 on UML, in which case, set this to 3.
198 It is possible to reduce the stack to 1 for 64BIT and 0 for 32BIT on
199 older (pre-2017) CPUs. It is not recommended on newer CPUs due to the
200 increase in the size of the state which needs to be saved when handling
201 signals.
202
203config MMAPPER
204 tristate "iomem emulation driver"
205 help
206 This driver allows a host file to be used as emulated IO memory inside
207 UML.
208
209config PGTABLE_LEVELS
210 int
211 default 3 if 3_LEVEL_PGTABLES
212 default 2
213
214config UML_TIME_TRAVEL_SUPPORT
215 bool
216 prompt "Support time-travel mode (e.g. for test execution)"
217 # inf-cpu mode is incompatible with the benchmarking
218 depends on !RAID6_PQ_BENCHMARK
219 depends on !SMP
220 help
221 Enable this option to support time travel inside the UML instance.
222
223 After enabling this option, two modes are accessible at runtime
224 (selected by the kernel command line), see the kernel's command-
225 line help for more details.
226
227 It is safe to say Y, but you probably don't need this.
228
229config KASAN_SHADOW_OFFSET
230 hex
231 depends on KASAN
232 default 0x100000000000
233 help
234 This is the offset at which the ~16TB of shadow memory is
235 mapped and used by KASAN for memory debugging. This can be any
236 address that has at least KASAN_SHADOW_SIZE (total address space divided
237 by 8) amount of space so that the KASAN shadow memory does not conflict
238 with anything. The default is 0x100000000000, which works even if mem is
239 set to a large value. On low-memory systems, try 0x7fff8000, as it fits
240 into the immediate of most instructions, improving performance.
241
242endmenu
243
244source "arch/um/drivers/Kconfig"
245
246config ARCH_SUSPEND_POSSIBLE
247 def_bool y
248
249menu "Power management options"
250
251source "kernel/power/Kconfig"
252
253endmenu