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 HAVE_ARCH_AUDITSYSCALL
15 select HAVE_ARCH_KASAN if X86_64
16 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
17 select HAVE_ARCH_SECCOMP_FILTER
18 select HAVE_ASM_MODVERSIONS
19 select HAVE_UID16
20 select HAVE_DEBUG_KMEMLEAK
21 select HAVE_DEBUG_BUGVERBOSE
22 select HAVE_PAGE_SIZE_4KB
23 select NO_DMA if !UML_DMA_EMULATION
24 select OF_EARLY_FLATTREE if OF
25 select GENERIC_IRQ_SHOW
26 select GENERIC_CPU_DEVICES
27 select HAVE_GCC_PLUGINS
28 select ARCH_SUPPORTS_LTO_CLANG
29 select ARCH_SUPPORTS_LTO_CLANG_THIN
30 select TRACE_IRQFLAGS_SUPPORT
31 select TTY # Needed for line.c
32 select HAVE_ARCH_VMAP_STACK
33 select HAVE_RUST
34 select ARCH_HAS_UBSAN
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 HAS_IOPORT
52 select GENERIC_PCI_IOMAP
53 select GENERIC_IOMAP
54 select NO_GENERIC_PCI_IOPORT_MAP
55
56config NO_IOPORT_MAP
57 def_bool !UML_IOMEM_EMULATION
58
59config ISA
60 bool
61
62config SBUS
63 bool
64
65config LOCKDEP_SUPPORT
66 bool
67 default y
68
69config STACKTRACE_SUPPORT
70 bool
71 default y
72 select STACKTRACE
73
74config GENERIC_CALIBRATE_DELAY
75 bool
76 default y
77
78config HZ
79 int
80 default 100
81
82config NR_CPUS
83 int
84 range 1 1
85 default 1
86
87config ARCH_HAS_CACHE_LINE_SIZE
88 def_bool y
89
90source "arch/$(HEADER_ARCH)/um/Kconfig"
91
92config MAY_HAVE_RUNTIME_DEPS
93 bool
94
95config STATIC_LINK
96 bool "Force a static link"
97 depends on CC_CAN_LINK_STATIC_NO_RUNTIME_DEPS || !MAY_HAVE_RUNTIME_DEPS
98 help
99 This option gives you the ability to force a static link of UML.
100 Normally, UML is linked as a shared binary. This is inconvenient for
101 use in a chroot jail. So, if you intend to run UML inside a chroot,
102 you probably want to say Y here.
103 Additionally, this option enables using higher memory spaces (up to
104 2.75G) for UML.
105
106 NOTE: This option is incompatible with some networking features which
107 depend on features that require being dynamically loaded (like NSS).
108
109config LD_SCRIPT_STATIC
110 bool
111 default y
112 depends on STATIC_LINK
113
114config LD_SCRIPT_DYN
115 bool
116 default y
117 depends on !LD_SCRIPT_STATIC
118
119config LD_SCRIPT_DYN_RPATH
120 bool "set rpath in the binary" if EXPERT
121 default y
122 depends on LD_SCRIPT_DYN
123 help
124 Add /lib (and /lib64 for 64-bit) to the linux binary's rpath
125 explicitly.
126
127 You may need to turn this off if compiling for nix systems
128 that have their libraries in random /nix directories and
129 might otherwise unexpected use libraries from /lib or /lib64
130 instead of the desired ones.
131
132config HOSTFS
133 tristate "Host filesystem"
134 help
135 While the User-Mode Linux port uses its own root file system for
136 booting and normal file access, this module lets the UML user
137 access files stored on the host. It does not require any
138 network connection between the Host and UML. An example use of
139 this might be:
140
141 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
142
143 where /tmp/fromhost is an empty directory inside UML and
144 /tmp/umlshare is a directory on the host with files the UML user
145 wishes to access.
146
147 For more information, see
148 <http://user-mode-linux.sourceforge.net/hostfs.html>.
149
150 If you'd like to be able to work with files stored on the host,
151 say Y or M here; otherwise say N.
152
153config MCONSOLE
154 bool "Management console"
155 depends on PROC_FS
156 default y
157 help
158 The user mode linux management console is a low-level interface to
159 the kernel, somewhat like the i386 SysRq interface. Since there is
160 a full-blown operating system running under every user mode linux
161 instance, there is much greater flexibility possible than with the
162 SysRq mechanism.
163
164 If you answer 'Y' to this option, to use this feature, you need the
165 mconsole client (called uml_mconsole) which is present in CVS in
166 2.4.5-9um and later (path /tools/mconsole), and is also in the
167 distribution RPM package in 2.4.6 and later.
168
169 It is safe to say 'Y' here.
170
171config MAGIC_SYSRQ
172 bool "Magic SysRq key"
173 depends on MCONSOLE
174 help
175 If you say Y here, you will have some control over the system even
176 if the system crashes for example during kernel debugging (e.g., you
177 will be able to flush the buffer cache to disk, reboot the system
178 immediately or dump some status information). A key for each of the
179 possible requests is provided.
180
181 This is the feature normally accomplished by pressing a key
182 while holding SysRq (Alt+PrintScreen).
183
184 On UML, this is accomplished by sending a "sysrq" command with
185 mconsole, followed by the letter for the requested command.
186
187 The keys are documented in <file:Documentation/admin-guide/sysrq.rst>. Don't say Y
188 unless you really know what this hack does.
189
190config KERNEL_STACK_ORDER
191 int "Kernel stack size order"
192 default 2 if 64BIT
193 range 2 10 if 64BIT
194 default 1 if !64BIT
195 help
196 This option determines the size of UML kernel stacks. They will
197 be 1 << order pages. The default is OK unless you're running Valgrind
198 on UML, in which case, set this to 3.
199 It is possible to reduce the stack to 1 for 64BIT and 0 for 32BIT on
200 older (pre-2017) CPUs. It is not recommended on newer CPUs due to the
201 increase in the size of the state which needs to be saved when handling
202 signals.
203
204config MMAPPER
205 tristate "iomem emulation driver"
206 help
207 This driver allows a host file to be used as emulated IO memory inside
208 UML.
209
210config PGTABLE_LEVELS
211 int
212 default 3 if 3_LEVEL_PGTABLES
213 default 2
214
215config UML_TIME_TRAVEL_SUPPORT
216 bool
217 prompt "Support time-travel mode (e.g. for test execution)"
218 # inf-cpu mode is incompatible with the benchmarking
219 depends on !RAID6_PQ_BENCHMARK
220 depends on !SMP
221 help
222 Enable this option to support time travel inside the UML instance.
223
224 After enabling this option, two modes are accessible at runtime
225 (selected by the kernel command line), see the kernel's command-
226 line help for more details.
227
228 It is safe to say Y, but you probably don't need this.
229
230config KASAN_SHADOW_OFFSET
231 hex
232 depends on KASAN
233 default 0x100000000000
234 help
235 This is the offset at which the ~16TB of shadow memory is
236 mapped and used by KASAN for memory debugging. This can be any
237 address that has at least KASAN_SHADOW_SIZE (total address space divided
238 by 8) amount of space so that the KASAN shadow memory does not conflict
239 with anything. The default is 0x100000000000, which works even if mem is
240 set to a large value. On low-memory systems, try 0x7fff8000, as it fits
241 into the immediate of most instructions, improving performance.
242
243endmenu
244
245source "arch/um/drivers/Kconfig"
246
247config ARCH_SUSPEND_POSSIBLE
248 def_bool y
249
250menu "Power management options"
251
252source "kernel/power/Kconfig"
253
254endmenu