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Commit | Line | Data |
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b2441318 | 1 | # SPDX-License-Identifier: GPL-2.0 |
daa93fab SR |
2 | # Select 32 or 64 bit |
3 | config 64BIT | |
104daea1 MY |
4 | bool "64-bit kernel" if "$(ARCH)" = "x86" |
5 | default "$(ARCH)" != "i386" | |
a7f7f624 | 6 | help |
daa93fab SR |
7 | Say yes to build a 64-bit kernel - formerly known as x86_64 |
8 | Say no to build a 32-bit kernel - formerly known as i386 | |
9 | ||
10 | config X86_32 | |
3120e25e JB |
11 | def_bool y |
12 | depends on !64BIT | |
341c787e IM |
13 | # Options that are inherently 32-bit kernel only: |
14 | select ARCH_WANT_IPC_PARSE_VERSION | |
15 | select CLKSRC_I8253 | |
16 | select CLONE_BACKWARDS | |
157e118b | 17 | select GENERIC_VDSO_32 |
117ed454 | 18 | select HAVE_DEBUG_STACKOVERFLOW |
157e118b | 19 | select KMAP_LOCAL |
341c787e IM |
20 | select MODULES_USE_ELF_REL |
21 | select OLD_SIGACTION | |
2ca408d9 | 22 | select ARCH_SPLIT_ARG64 |
daa93fab SR |
23 | |
24 | config X86_64 | |
3120e25e JB |
25 | def_bool y |
26 | depends on 64BIT | |
d94e0685 | 27 | # Options that are inherently 64-bit kernel only: |
4eb0716e | 28 | select ARCH_HAS_GIGANTIC_PAGE |
c12d3362 | 29 | select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 |
0bff0aae | 30 | select ARCH_SUPPORTS_PER_VMA_LOCK |
d94e0685 IM |
31 | select ARCH_USE_CMPXCHG_LOCKREF |
32 | select HAVE_ARCH_SOFT_DIRTY | |
33 | select MODULES_USE_ELF_RELA | |
f616ab59 | 34 | select NEED_DMA_MAP_STATE |
09230cbc | 35 | select SWIOTLB |
7facdc42 | 36 | select ARCH_HAS_ELFCORE_COMPAT |
63703f37 | 37 | select ZONE_DMA32 |
1032c0ba | 38 | |
518049d9 SRV |
39 | config FORCE_DYNAMIC_FTRACE |
40 | def_bool y | |
41 | depends on X86_32 | |
42 | depends on FUNCTION_TRACER | |
43 | select DYNAMIC_FTRACE | |
44 | help | |
758cd94a JH |
45 | We keep the static function tracing (!DYNAMIC_FTRACE) around |
46 | in order to test the non static function tracing in the | |
47 | generic code, as other architectures still use it. But we | |
48 | only need to keep it around for x86_64. No need to keep it | |
49 | for x86_32. For x86_32, force DYNAMIC_FTRACE. | |
d94e0685 IM |
50 | # |
51 | # Arch settings | |
52 | # | |
53 | # ( Note that options that are marked 'if X86_64' could in principle be | |
54 | # ported to 32-bit as well. ) | |
55 | # | |
8d5fffb9 | 56 | config X86 |
3c2362e6 | 57 | def_bool y |
c763ea26 IM |
58 | # |
59 | # Note: keep this list sorted alphabetically | |
60 | # | |
6471b825 IM |
61 | select ACPI_LEGACY_TABLES_LOOKUP if ACPI |
62 | select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI | |
942fa985 | 63 | select ARCH_32BIT_OFF_T if X86_32 |
2a21ad57 | 64 | select ARCH_CLOCKSOURCE_INIT |
1f6d3a8f | 65 | select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE |
1e866974 | 66 | select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION |
5c11f00b | 67 | select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 |
91024b3c | 68 | select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG |
cebc774f | 69 | select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) |
1e866974 | 70 | select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE |
c763ea26 | 71 | select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI |
c2280be8 | 72 | select ARCH_HAS_CACHE_LINE_SIZE |
1156b441 | 73 | select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION |
7c7077a7 | 74 | select ARCH_HAS_CPU_FINALIZE_INIT |
2792d84e | 75 | select ARCH_HAS_CURRENT_STACK_POINTER |
fa5b6ec9 | 76 | select ARCH_HAS_DEBUG_VIRTUAL |
399145f9 | 77 | select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE |
21266be9 | 78 | select ARCH_HAS_DEVMEM_IS_ALLOWED |
b1a57bbf | 79 | select ARCH_HAS_EARLY_DEBUG if KGDB |
6471b825 | 80 | select ARCH_HAS_ELF_RANDOMIZE |
72d93104 | 81 | select ARCH_HAS_FAST_MULTIPLIER |
6974f0c4 | 82 | select ARCH_HAS_FORTIFY_SOURCE |
957e3fac | 83 | select ARCH_HAS_GCOV_PROFILE_ALL |
bece04b5 | 84 | select ARCH_HAS_KCOV if X86_64 |
0c9c1d56 | 85 | select ARCH_HAS_MEM_ENCRYPT |
10bcc80e | 86 | select ARCH_HAS_MEMBARRIER_SYNC_CORE |
49f88c70 | 87 | select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS |
0ebeea8c | 88 | select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
c763ea26 | 89 | select ARCH_HAS_PMEM_API if X86_64 |
17596731 | 90 | select ARCH_HAS_PTE_DEVMAP if X86_64 |
3010a5ea | 91 | select ARCH_HAS_PTE_SPECIAL |
eed9a328 | 92 | select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2 |
0aed55af | 93 | select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 |
ec6347bb | 94 | select ARCH_HAS_COPY_MC if X86_64 |
d2852a22 | 95 | select ARCH_HAS_SET_MEMORY |
d253ca0c | 96 | select ARCH_HAS_SET_DIRECT_MAP |
ad21fc4f LA |
97 | select ARCH_HAS_STRICT_KERNEL_RWX |
98 | select ARCH_HAS_STRICT_MODULE_RWX | |
ac1ab12a | 99 | select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE |
25c619e5 | 100 | select ARCH_HAS_SYSCALL_WRAPPER |
c6d30853 | 101 | select ARCH_HAS_UBSAN_SANITIZE_ALL |
7e01ccb4 | 102 | select ARCH_HAS_DEBUG_WX |
63703f37 | 103 | select ARCH_HAS_ZONE_DMA_SET if EXPERT |
6471b825 | 104 | select ARCH_HAVE_NMI_SAFE_CMPXCHG |
04d5ea46 | 105 | select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE |
6471b825 | 106 | select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI |
77fbbc81 | 107 | select ARCH_MIGHT_HAVE_PC_PARPORT |
5e2c18c0 | 108 | select ARCH_MIGHT_HAVE_PC_SERIO |
3599fe12 | 109 | select ARCH_STACKWALK |
2c870e61 | 110 | select ARCH_SUPPORTS_ACPI |
6471b825 | 111 | select ARCH_SUPPORTS_ATOMIC_RMW |
5d6ad668 | 112 | select ARCH_SUPPORTS_DEBUG_PAGEALLOC |
d283d422 | 113 | select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 |
6471b825 | 114 | select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 |
14df3267 | 115 | select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 |
3c516f89 ST |
116 | select ARCH_SUPPORTS_CFI_CLANG if X86_64 |
117 | select ARCH_USES_CFI_TRAPS if X86_64 && CFI_CLANG | |
583bfd48 NC |
118 | select ARCH_SUPPORTS_LTO_CLANG |
119 | select ARCH_SUPPORTS_LTO_CLANG_THIN | |
6471b825 | 120 | select ARCH_USE_BUILTIN_BSWAP |
dce44566 | 121 | select ARCH_USE_MEMTEST |
6471b825 IM |
122 | select ARCH_USE_QUEUED_RWLOCKS |
123 | select ARCH_USE_QUEUED_SPINLOCKS | |
2ce0d7f9 | 124 | select ARCH_USE_SYM_ANNOTATIONS |
ce4a4e56 | 125 | select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH |
81c22041 | 126 | select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 |
c763ea26 | 127 | select ARCH_WANTS_DYNAMIC_TASK_STRUCT |
51c2ee6d | 128 | select ARCH_WANTS_NO_INSTR |
07431506 | 129 | select ARCH_WANT_GENERAL_HUGETLB |
3876d4a3 | 130 | select ARCH_WANT_HUGE_PMD_SHARE |
59612b24 | 131 | select ARCH_WANT_LD_ORPHAN_WARN |
0b6f1582 AK |
132 | select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64 |
133 | select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64 | |
38d8b4e6 | 134 | select ARCH_WANTS_THP_SWAP if X86_64 |
b5f06f64 | 135 | select ARCH_HAS_PARANOID_L1D_FLUSH |
10916706 | 136 | select BUILDTIME_TABLE_SORT |
6471b825 | 137 | select CLKEVT_I8253 |
6471b825 IM |
138 | select CLOCKSOURCE_VALIDATE_LAST_CYCLE |
139 | select CLOCKSOURCE_WATCHDOG | |
7cf8f44a AP |
140 | # Word-size accesses may read uninitialized data past the trailing \0 |
141 | # in strings and cause false KMSAN reports. | |
142 | select DCACHE_WORD_ACCESS if !KMSAN | |
3aac3ebe | 143 | select DYNAMIC_SIGFRAME |
45471cd9 LT |
144 | select EDAC_ATOMIC_SCRUB |
145 | select EDAC_SUPPORT | |
6471b825 IM |
146 | select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) |
147 | select GENERIC_CLOCKEVENTS_MIN_ADJUST | |
148 | select GENERIC_CMOS_UPDATE | |
149 | select GENERIC_CPU_AUTOPROBE | |
61dc0f55 | 150 | select GENERIC_CPU_VULNERABILITIES |
5b7c73e0 | 151 | select GENERIC_EARLY_IOREMAP |
27d6b4d1 | 152 | select GENERIC_ENTRY |
6471b825 | 153 | select GENERIC_IOMAP |
c7d6c9dd | 154 | select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP |
0fa115da | 155 | select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC |
ad7a929f | 156 | select GENERIC_IRQ_MIGRATION if SMP |
6471b825 | 157 | select GENERIC_IRQ_PROBE |
c201c917 | 158 | select GENERIC_IRQ_RESERVATION_MODE |
6471b825 IM |
159 | select GENERIC_IRQ_SHOW |
160 | select GENERIC_PENDING_IRQ if SMP | |
2ae27137 | 161 | select GENERIC_PTDUMP |
6471b825 | 162 | select GENERIC_SMP_IDLE_THREAD |
6471b825 | 163 | select GENERIC_TIME_VSYSCALL |
7ac87074 | 164 | select GENERIC_GETTIMEOFDAY |
550a77a7 | 165 | select GENERIC_VDSO_TIME_NS |
6ca297d4 | 166 | select GUP_GET_PXX_LOW_HIGH if X86_PAE |
17e5888e | 167 | select HARDIRQS_SW_RESEND |
7edaeb68 | 168 | select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 |
fcbfe812 | 169 | select HAS_IOPORT |
6471b825 IM |
170 | select HAVE_ACPI_APEI if ACPI |
171 | select HAVE_ACPI_APEI_NMI if ACPI | |
172 | select HAVE_ALIGNED_STRUCT_PAGE if SLUB | |
6471b825 IM |
173 | select HAVE_ARCH_AUDITSYSCALL |
174 | select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE | |
eed1fcee | 175 | select HAVE_ARCH_HUGE_VMALLOC if X86_64 |
6471b825 | 176 | select HAVE_ARCH_JUMP_LABEL |
b34006c4 | 177 | select HAVE_ARCH_JUMP_LABEL_RELATIVE |
d17a1d97 | 178 | select HAVE_ARCH_KASAN if X86_64 |
0609ae01 | 179 | select HAVE_ARCH_KASAN_VMALLOC if X86_64 |
1dc0da6e | 180 | select HAVE_ARCH_KFENCE |
4ca8cc8d | 181 | select HAVE_ARCH_KMSAN if X86_64 |
6471b825 | 182 | select HAVE_ARCH_KGDB |
9e08f57d DC |
183 | select HAVE_ARCH_MMAP_RND_BITS if MMU |
184 | select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT | |
1b028f78 | 185 | select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT |
271ca788 | 186 | select HAVE_ARCH_PREL32_RELOCATIONS |
6471b825 | 187 | select HAVE_ARCH_SECCOMP_FILTER |
f7d83c1c | 188 | select HAVE_ARCH_THREAD_STRUCT_WHITELIST |
afaef01c | 189 | select HAVE_ARCH_STACKLEAK |
6471b825 IM |
190 | select HAVE_ARCH_TRACEHOOK |
191 | select HAVE_ARCH_TRANSPARENT_HUGEPAGE | |
a00cc7d9 | 192 | select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 |
b64d8d1e | 193 | select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD |
7677f7fd | 194 | select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD |
e37e43a4 | 195 | select HAVE_ARCH_VMAP_STACK if X86_64 |
fe950f60 | 196 | select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET |
c763ea26 | 197 | select HAVE_ARCH_WITHIN_STACK_FRAMES |
2ff2b7ec | 198 | select HAVE_ASM_MODVERSIONS |
6471b825 IM |
199 | select HAVE_CMPXCHG_DOUBLE |
200 | select HAVE_CMPXCHG_LOCAL | |
24a9c541 FW |
201 | select HAVE_CONTEXT_TRACKING_USER if X86_64 |
202 | select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER | |
cf4db259 | 203 | select HAVE_C_RECORDMCOUNT |
03f16cd0 | 204 | select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL |
280981d6 | 205 | select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT |
4ed308c4 | 206 | select HAVE_BUILDTIME_MCOUNT_SORT |
6471b825 | 207 | select HAVE_DEBUG_KMEMLEAK |
6471b825 | 208 | select HAVE_DMA_CONTIGUOUS |
677aa9f7 | 209 | select HAVE_DYNAMIC_FTRACE |
06aeaaea | 210 | select HAVE_DYNAMIC_FTRACE_WITH_REGS |
02a474ca | 211 | select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 |
562955fe | 212 | select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
c316eb44 | 213 | select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 |
503e4510 | 214 | select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 |
03f5781b | 215 | select HAVE_EBPF_JIT |
58340a07 | 216 | select HAVE_EFFICIENT_UNALIGNED_ACCESS |
6630a8e5 | 217 | select HAVE_EISA |
5f56a5df | 218 | select HAVE_EXIT_THREAD |
67a929e0 | 219 | select HAVE_FAST_GUP |
644e0e8d | 220 | select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE |
6471b825 | 221 | select HAVE_FTRACE_MCOUNT_RECORD |
d938ba17 | 222 | select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER |
4a30e4c9 | 223 | select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) |
6471b825 | 224 | select HAVE_FUNCTION_TRACER |
6b90bd4b | 225 | select HAVE_GCC_PLUGINS |
6471b825 | 226 | select HAVE_HW_BREAKPOINT |
6471b825 | 227 | select HAVE_IOREMAP_PROT |
624db9ea | 228 | select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 |
6471b825 | 229 | select HAVE_IRQ_TIME_ACCOUNTING |
4ab7674f | 230 | select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL |
2e9f3bdd | 231 | select HAVE_KERNEL_BZIP2 |
6471b825 IM |
232 | select HAVE_KERNEL_GZIP |
233 | select HAVE_KERNEL_LZ4 | |
2e9f3bdd | 234 | select HAVE_KERNEL_LZMA |
13510997 | 235 | select HAVE_KERNEL_LZO |
6471b825 | 236 | select HAVE_KERNEL_XZ |
fb46d057 | 237 | select HAVE_KERNEL_ZSTD |
6471b825 IM |
238 | select HAVE_KPROBES |
239 | select HAVE_KPROBES_ON_FTRACE | |
540adea3 | 240 | select HAVE_FUNCTION_ERROR_INJECTION |
6471b825 | 241 | select HAVE_KRETPROBES |
f3a112c0 | 242 | select HAVE_RETHOOK |
6471b825 IM |
243 | select HAVE_KVM |
244 | select HAVE_LIVEPATCH if X86_64 | |
0102752e | 245 | select HAVE_MIXED_BREAKPOINTS_REGS |
ee9f8fce | 246 | select HAVE_MOD_ARCH_SPECIFIC |
9f132f7e | 247 | select HAVE_MOVE_PMD |
be37c98d | 248 | select HAVE_MOVE_PUD |
22102f45 | 249 | select HAVE_NOINSTR_HACK if HAVE_OBJTOOL |
42a0bb3f | 250 | select HAVE_NMI |
489e355b | 251 | select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL |
03f16cd0 | 252 | select HAVE_OBJTOOL if X86_64 |
6471b825 IM |
253 | select HAVE_OPTPROBES |
254 | select HAVE_PCSPKR_PLATFORM | |
255 | select HAVE_PERF_EVENTS | |
c01d4323 | 256 | select HAVE_PERF_EVENTS_NMI |
92e5aae4 | 257 | select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI |
eb01d42a | 258 | select HAVE_PCI |
c5e63197 | 259 | select HAVE_PERF_REGS |
c5ebcedb | 260 | select HAVE_PERF_USER_STACK_DUMP |
03f16cd0 | 261 | select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT |
1e9fdf21 | 262 | select MMU_GATHER_MERGE_VMAS |
00998085 | 263 | select HAVE_POSIX_CPU_TIMERS_TASK_WORK |
6471b825 | 264 | select HAVE_REGS_AND_STACK_ACCESS_API |
03f16cd0 | 265 | select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION |
3c88ee19 | 266 | select HAVE_FUNCTION_ARG_ACCESS_API |
7ecd19cf | 267 | select HAVE_SETUP_PER_CPU_AREA |
cd1a41ce | 268 | select HAVE_SOFTIRQ_ON_OWN_STACK |
d148eac0 | 269 | select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR |
03f16cd0 | 270 | select HAVE_STACK_VALIDATION if HAVE_OBJTOOL |
e6d6c071 | 271 | select HAVE_STATIC_CALL |
03f16cd0 | 272 | select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL |
99cf983c | 273 | select HAVE_PREEMPT_DYNAMIC_CALL |
d6761b8f | 274 | select HAVE_RSEQ |
09498135 | 275 | select HAVE_RUST if X86_64 |
6471b825 | 276 | select HAVE_SYSCALL_TRACEPOINTS |
5f3da8c0 | 277 | select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL |
6471b825 | 278 | select HAVE_UNSTABLE_SCHED_CLOCK |
7c68af6e | 279 | select HAVE_USER_RETURN_NOTIFIER |
7ac87074 | 280 | select HAVE_GENERIC_VDSO |
0c7ffa32 | 281 | select HOTPLUG_PARALLEL if SMP && X86_64 |
05736e4a | 282 | select HOTPLUG_SMT if SMP |
0c7ffa32 | 283 | select HOTPLUG_SPLIT_STARTUP if SMP && X86_32 |
c0185808 | 284 | select IRQ_FORCED_THREADING |
c2508ec5 | 285 | select LOCK_MM_AND_FIND_VMA |
7ecd19cf KW |
286 | select NEED_PER_CPU_EMBED_FIRST_CHUNK |
287 | select NEED_PER_CPU_PAGE_FIRST_CHUNK | |
86596f0a | 288 | select NEED_SG_DMA_LENGTH |
2eac9c2d | 289 | select PCI_DOMAINS if PCI |
625210cf | 290 | select PCI_LOCKLESS_CONFIG if PCI |
6471b825 | 291 | select PERF_EVENTS |
3195ef59 | 292 | select RTC_LIB |
d6faca40 | 293 | select RTC_MC146818_LIB |
6471b825 | 294 | select SPARSE_IRQ |
6471b825 | 295 | select SYSCTL_EXCEPTION_TRACE |
15f4eae7 | 296 | select THREAD_INFO_IN_TASK |
4aae683f | 297 | select TRACE_IRQFLAGS_SUPPORT |
4510bffb | 298 | select TRACE_IRQFLAGS_NMI_SUPPORT |
6471b825 | 299 | select USER_STACKTRACE_SUPPORT |
3b02a051 | 300 | select HAVE_ARCH_KCSAN if X86_64 |
0c608dad | 301 | select PROC_PID_ARCH_STATUS if PROC_FS |
50468e43 | 302 | select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX |
d49a0626 PZ |
303 | select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16 |
304 | select FUNCTION_ALIGNMENT_4B | |
9e2b4be3 | 305 | imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI |
ceea991a | 306 | select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE |
7d8330a5 | 307 | |
ba7e4d13 | 308 | config INSTRUCTION_DECODER |
3120e25e JB |
309 | def_bool y |
310 | depends on KPROBES || PERF_EVENTS || UPROBES | |
ba7e4d13 | 311 | |
51b26ada LT |
312 | config OUTPUT_FORMAT |
313 | string | |
314 | default "elf32-i386" if X86_32 | |
315 | default "elf64-x86-64" if X86_64 | |
316 | ||
8d5fffb9 | 317 | config LOCKDEP_SUPPORT |
3c2362e6 | 318 | def_bool y |
8d5fffb9 SR |
319 | |
320 | config STACKTRACE_SUPPORT | |
3c2362e6 | 321 | def_bool y |
8d5fffb9 | 322 | |
8d5fffb9 | 323 | config MMU |
3c2362e6 | 324 | def_bool y |
8d5fffb9 | 325 | |
9e08f57d DC |
326 | config ARCH_MMAP_RND_BITS_MIN |
327 | default 28 if 64BIT | |
328 | default 8 | |
329 | ||
330 | config ARCH_MMAP_RND_BITS_MAX | |
331 | default 32 if 64BIT | |
332 | default 16 | |
333 | ||
334 | config ARCH_MMAP_RND_COMPAT_BITS_MIN | |
335 | default 8 | |
336 | ||
337 | config ARCH_MMAP_RND_COMPAT_BITS_MAX | |
338 | default 16 | |
339 | ||
8d5fffb9 SR |
340 | config SBUS |
341 | bool | |
342 | ||
343 | config GENERIC_ISA_DMA | |
3120e25e JB |
344 | def_bool y |
345 | depends on ISA_DMA_API | |
8d5fffb9 | 346 | |
d911c67e AP |
347 | config GENERIC_CSUM |
348 | bool | |
349 | default y if KMSAN || KASAN | |
350 | ||
8d5fffb9 | 351 | config GENERIC_BUG |
3c2362e6 | 352 | def_bool y |
8d5fffb9 | 353 | depends on BUG |
b93a531e JB |
354 | select GENERIC_BUG_RELATIVE_POINTERS if X86_64 |
355 | ||
356 | config GENERIC_BUG_RELATIVE_POINTERS | |
357 | bool | |
8d5fffb9 | 358 | |
8d5fffb9 | 359 | config ARCH_MAY_HAVE_PC_FDC |
3120e25e JB |
360 | def_bool y |
361 | depends on ISA_DMA_API | |
8d5fffb9 | 362 | |
1032c0ba SR |
363 | config GENERIC_CALIBRATE_DELAY |
364 | def_bool y | |
365 | ||
9a0b8415 | 366 | config ARCH_HAS_CPU_RELAX |
367 | def_bool y | |
368 | ||
801e4062 JB |
369 | config ARCH_HIBERNATION_POSSIBLE |
370 | def_bool y | |
801e4062 | 371 | |
f4cb5700 JB |
372 | config ARCH_SUSPEND_POSSIBLE |
373 | def_bool y | |
f4cb5700 | 374 | |
8d5fffb9 | 375 | config AUDIT_ARCH |
e0fd24a3 | 376 | def_bool y if X86_64 |
8d5fffb9 | 377 | |
d6f2d75a AR |
378 | config KASAN_SHADOW_OFFSET |
379 | hex | |
380 | depends on KASAN | |
381 | default 0xdffffc0000000000 | |
382 | ||
69575d38 SW |
383 | config HAVE_INTEL_TXT |
384 | def_bool y | |
6ea30386 | 385 | depends on INTEL_IOMMU && ACPI |
69575d38 | 386 | |
6b0c3d44 SR |
387 | config X86_32_SMP |
388 | def_bool y | |
389 | depends on X86_32 && SMP | |
390 | ||
391 | config X86_64_SMP | |
392 | def_bool y | |
393 | depends on X86_64 && SMP | |
394 | ||
2b144498 SD |
395 | config ARCH_SUPPORTS_UPROBES |
396 | def_bool y | |
397 | ||
d20642f0 RH |
398 | config FIX_EARLYCON_MEM |
399 | def_bool y | |
400 | ||
94d49eb3 KS |
401 | config DYNAMIC_PHYSICAL_MASK |
402 | bool | |
403 | ||
98233368 KS |
404 | config PGTABLE_LEVELS |
405 | int | |
77ef56e4 | 406 | default 5 if X86_5LEVEL |
98233368 KS |
407 | default 4 if X86_64 |
408 | default 3 if X86_PAE | |
409 | default 2 | |
410 | ||
2a61f474 MY |
411 | config CC_HAS_SANE_STACKPROTECTOR |
412 | bool | |
1b866781 NC |
413 | default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT |
414 | default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) | |
2a61f474 | 415 | help |
758cd94a JH |
416 | We have to make sure stack protector is unconditionally disabled if |
417 | the compiler produces broken code or if it does not let us control | |
418 | the segment on 32-bit kernels. | |
2a61f474 | 419 | |
506f1d07 SR |
420 | menu "Processor type and features" |
421 | ||
506f1d07 SR |
422 | config SMP |
423 | bool "Symmetric multi-processing support" | |
a7f7f624 | 424 | help |
506f1d07 | 425 | This enables support for systems with more than one CPU. If you have |
4a474157 RG |
426 | a system with only one CPU, say N. If you have a system with more |
427 | than one CPU, say Y. | |
506f1d07 | 428 | |
4a474157 | 429 | If you say N here, the kernel will run on uni- and multiprocessor |
506f1d07 SR |
430 | machines, but will use only one CPU of a multiprocessor machine. If |
431 | you say Y here, the kernel will run on many, but not all, | |
4a474157 | 432 | uniprocessor machines. On a uniprocessor machine, the kernel |
506f1d07 SR |
433 | will run faster if you say N here. |
434 | ||
435 | Note that if you say Y here and choose architecture "586" or | |
436 | "Pentium" under "Processor family", the kernel will not work on 486 | |
437 | architectures. Similarly, multiprocessor kernels for the "PPro" | |
438 | architecture may not work on all Pentium based boards. | |
439 | ||
440 | People using multiprocessor machines who say Y here should also say | |
441 | Y to "Enhanced Real Time Clock Support", below. The "Advanced Power | |
442 | Management" code will be disabled if you say Y here. | |
443 | ||
ff61f079 | 444 | See also <file:Documentation/arch/x86/i386/IO-APIC.rst>, |
4f4cfa6c | 445 | <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at |
506f1d07 SR |
446 | <http://www.tldp.org/docs.html#howto>. |
447 | ||
448 | If you don't know what to do here, say N. | |
449 | ||
06cd9a7d YL |
450 | config X86_X2APIC |
451 | bool "Support x2apic" | |
19e3d60d | 452 | depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) |
a7f7f624 | 453 | help |
06cd9a7d YL |
454 | This enables x2apic support on CPUs that have this feature. |
455 | ||
456 | This allows 32-bit apic IDs (so it can support very large systems), | |
457 | and accesses the local apic via MSRs not via mmio. | |
458 | ||
b8d1d163 DS |
459 | Some Intel systems circa 2022 and later are locked into x2APIC mode |
460 | and can not fall back to the legacy APIC modes if SGX or TDX are | |
e3998434 MJ |
461 | enabled in the BIOS. They will boot with very reduced functionality |
462 | without enabling this option. | |
b8d1d163 | 463 | |
06cd9a7d YL |
464 | If you don't know what to do here, say N. |
465 | ||
6695c85b | 466 | config X86_MPPARSE |
4590d98f | 467 | bool "Enable MPS table" if ACPI |
7a527688 | 468 | default y |
5ab74722 | 469 | depends on X86_LOCAL_APIC |
a7f7f624 | 470 | help |
6695c85b YL |
471 | For old smp systems that do not have proper acpi support. Newer systems |
472 | (esp with 64bit cpus) with acpi support, MADT and DSDT will override it | |
6695c85b | 473 | |
ddd70cf9 | 474 | config GOLDFISH |
b03b016f KK |
475 | def_bool y |
476 | depends on X86_GOLDFISH | |
ddd70cf9 | 477 | |
e6d42931 JW |
478 | config X86_CPU_RESCTRL |
479 | bool "x86 CPU resource control support" | |
6fe07ce3 | 480 | depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) |
59fe5a77 | 481 | select KERNFS |
e79f15a4 | 482 | select PROC_CPU_RESCTRL if PROC_FS |
78e99b4a | 483 | help |
e6d42931 | 484 | Enable x86 CPU resource control support. |
6fe07ce3 BM |
485 | |
486 | Provide support for the allocation and monitoring of system resources | |
487 | usage by the CPU. | |
488 | ||
489 | Intel calls this Intel Resource Director Technology | |
490 | (Intel(R) RDT). More information about RDT can be found in the | |
491 | Intel x86 Architecture Software Developer Manual. | |
492 | ||
493 | AMD calls this AMD Platform Quality of Service (AMD QoS). | |
494 | More information about AMD QoS can be found in the AMD64 Technology | |
495 | Platform Quality of Service Extensions manual. | |
78e99b4a FY |
496 | |
497 | Say N if unsure. | |
498 | ||
8425091f | 499 | if X86_32 |
a0d0bb4d RD |
500 | config X86_BIGSMP |
501 | bool "Support for big SMP systems with more than 8 CPUs" | |
502 | depends on SMP | |
a7f7f624 | 503 | help |
e133f6ea | 504 | This option is needed for the systems that have more than 8 CPUs. |
a0d0bb4d | 505 | |
c5c606d9 RT |
506 | config X86_EXTENDED_PLATFORM |
507 | bool "Support for extended (non-PC) x86 platforms" | |
508 | default y | |
a7f7f624 | 509 | help |
06ac8346 IM |
510 | If you disable this option then the kernel will only support |
511 | standard PC platforms. (which covers the vast majority of | |
512 | systems out there.) | |
513 | ||
8425091f RT |
514 | If you enable this option then you'll be able to select support |
515 | for the following (non-PC) 32 bit x86 platforms: | |
cb7b8023 | 516 | Goldfish (Android emulator) |
8425091f | 517 | AMD Elan |
8425091f RT |
518 | RDC R-321x SoC |
519 | SGI 320/540 (Visual Workstation) | |
83125a3a | 520 | STA2X11-based (e.g. Northville) |
3f4110a4 | 521 | Moorestown MID devices |
06ac8346 IM |
522 | |
523 | If you have one of these systems, or if you want to build a | |
524 | generic distribution kernel, say Y here - otherwise say N. | |
758cd94a | 525 | endif # X86_32 |
06ac8346 | 526 | |
8425091f RT |
527 | if X86_64 |
528 | config X86_EXTENDED_PLATFORM | |
529 | bool "Support for extended (non-PC) x86 platforms" | |
530 | default y | |
a7f7f624 | 531 | help |
8425091f RT |
532 | If you disable this option then the kernel will only support |
533 | standard PC platforms. (which covers the vast majority of | |
534 | systems out there.) | |
535 | ||
536 | If you enable this option then you'll be able to select support | |
537 | for the following (non-PC) 64 bit x86 platforms: | |
44b111b5 | 538 | Numascale NumaChip |
8425091f RT |
539 | ScaleMP vSMP |
540 | SGI Ultraviolet | |
541 | ||
542 | If you have one of these systems, or if you want to build a | |
543 | generic distribution kernel, say Y here - otherwise say N. | |
758cd94a | 544 | endif # X86_64 |
c5c606d9 RT |
545 | # This is an alphabetically sorted list of 64 bit extended platforms |
546 | # Please maintain the alphabetic order if and when there are additions | |
44b111b5 SP |
547 | config X86_NUMACHIP |
548 | bool "Numascale NumaChip" | |
549 | depends on X86_64 | |
550 | depends on X86_EXTENDED_PLATFORM | |
551 | depends on NUMA | |
552 | depends on SMP | |
553 | depends on X86_X2APIC | |
f9726bfd | 554 | depends on PCI_MMCONFIG |
a7f7f624 | 555 | help |
44b111b5 SP |
556 | Adds support for Numascale NumaChip large-SMP systems. Needed to |
557 | enable more than ~168 cores. | |
558 | If you don't have one of these, you should say N here. | |
506f1d07 | 559 | |
c5c606d9 RT |
560 | config X86_VSMP |
561 | bool "ScaleMP vSMP" | |
6276a074 | 562 | select HYPERVISOR_GUEST |
c5c606d9 RT |
563 | select PARAVIRT |
564 | depends on X86_64 && PCI | |
565 | depends on X86_EXTENDED_PLATFORM | |
ead91d4b | 566 | depends on SMP |
a7f7f624 | 567 | help |
c5c606d9 RT |
568 | Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is |
569 | supposed to run on these EM64T-based machines. Only choose this option | |
570 | if you have one of these machines. | |
5e3a77e9 | 571 | |
03b48632 NP |
572 | config X86_UV |
573 | bool "SGI Ultraviolet" | |
574 | depends on X86_64 | |
c5c606d9 | 575 | depends on X86_EXTENDED_PLATFORM |
54c28d29 | 576 | depends on NUMA |
1ecb4ae5 | 577 | depends on EFI |
c2209ea5 | 578 | depends on KEXEC_CORE |
9d6c26e7 | 579 | depends on X86_X2APIC |
1222e564 | 580 | depends on PCI |
a7f7f624 | 581 | help |
03b48632 NP |
582 | This option is needed in order to support SGI Ultraviolet systems. |
583 | If you don't have one of these, you should say N here. | |
584 | ||
c5c606d9 RT |
585 | # Following is an alphabetically sorted list of 32 bit extended platforms |
586 | # Please maintain the alphabetic order if and when there are additions | |
506f1d07 | 587 | |
ddd70cf9 | 588 | config X86_GOLDFISH |
b03b016f KK |
589 | bool "Goldfish (Virtual Platform)" |
590 | depends on X86_EXTENDED_PLATFORM | |
a7f7f624 | 591 | help |
758cd94a JH |
592 | Enable support for the Goldfish virtual platform used primarily |
593 | for Android development. Unless you are building for the Android | |
594 | Goldfish emulator say N here. | |
ddd70cf9 | 595 | |
c751e17b TG |
596 | config X86_INTEL_CE |
597 | bool "CE4100 TV platform" | |
598 | depends on PCI | |
599 | depends on PCI_GODIRECT | |
6084a6e2 | 600 | depends on X86_IO_APIC |
c751e17b TG |
601 | depends on X86_32 |
602 | depends on X86_EXTENDED_PLATFORM | |
37bc9f50 | 603 | select X86_REBOOTFIXUPS |
da6b737b SAS |
604 | select OF |
605 | select OF_EARLY_FLATTREE | |
a7f7f624 | 606 | help |
c751e17b TG |
607 | Select for the Intel CE media processor (CE4100) SOC. |
608 | This option compiles in support for the CE4100 SOC for settop | |
609 | boxes and media devices. | |
610 | ||
4cb9b00f | 611 | config X86_INTEL_MID |
43605ef1 | 612 | bool "Intel MID platform support" |
43605ef1 | 613 | depends on X86_EXTENDED_PLATFORM |
edc6bc78 | 614 | depends on X86_PLATFORM_DEVICES |
1ea7c673 | 615 | depends on PCI |
3fda5bb4 | 616 | depends on X86_64 || (PCI_GOANY && X86_32) |
1ea7c673 | 617 | depends on X86_IO_APIC |
4cb9b00f | 618 | select I2C |
7c9c3a1e | 619 | select DW_APB_TIMER |
54b34aa0 | 620 | select INTEL_SCU_PCI |
a7f7f624 | 621 | help |
4cb9b00f DC |
622 | Select to build a kernel capable of supporting Intel MID (Mobile |
623 | Internet Device) platform systems which do not have the PCI legacy | |
624 | interfaces. If you are building for a PC class system say N here. | |
1ea7c673 | 625 | |
4cb9b00f DC |
626 | Intel MID platforms are based on an Intel processor and chipset which |
627 | consume less power than most of the x86 derivatives. | |
43605ef1 | 628 | |
8bbc2a13 BD |
629 | config X86_INTEL_QUARK |
630 | bool "Intel Quark platform support" | |
631 | depends on X86_32 | |
632 | depends on X86_EXTENDED_PLATFORM | |
633 | depends on X86_PLATFORM_DEVICES | |
634 | depends on X86_TSC | |
635 | depends on PCI | |
636 | depends on PCI_GOANY | |
637 | depends on X86_IO_APIC | |
638 | select IOSF_MBI | |
639 | select INTEL_IMR | |
9ab6eb51 | 640 | select COMMON_CLK |
a7f7f624 | 641 | help |
8bbc2a13 BD |
642 | Select to include support for Quark X1000 SoC. |
643 | Say Y here if you have a Quark based system such as the Arduino | |
644 | compatible Intel Galileo. | |
645 | ||
3d48aab1 MW |
646 | config X86_INTEL_LPSS |
647 | bool "Intel Low Power Subsystem Support" | |
5962dd22 | 648 | depends on X86 && ACPI && PCI |
3d48aab1 | 649 | select COMMON_CLK |
0f531431 | 650 | select PINCTRL |
eebb3e8d | 651 | select IOSF_MBI |
a7f7f624 | 652 | help |
3d48aab1 MW |
653 | Select to build support for Intel Low Power Subsystem such as |
654 | found on Intel Lynxpoint PCH. Selecting this option enables | |
0f531431 MN |
655 | things like clock tree (common clock framework) and pincontrol |
656 | which are needed by the LPSS peripheral drivers. | |
3d48aab1 | 657 | |
92082a88 KX |
658 | config X86_AMD_PLATFORM_DEVICE |
659 | bool "AMD ACPI2Platform devices support" | |
660 | depends on ACPI | |
661 | select COMMON_CLK | |
662 | select PINCTRL | |
a7f7f624 | 663 | help |
92082a88 KX |
664 | Select to interpret AMD specific ACPI device to platform device |
665 | such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. | |
666 | I2C and UART depend on COMMON_CLK to set clock. GPIO driver is | |
667 | implemented under PINCTRL subsystem. | |
668 | ||
ced3ce76 DB |
669 | config IOSF_MBI |
670 | tristate "Intel SoC IOSF Sideband support for SoC platforms" | |
671 | depends on PCI | |
a7f7f624 | 672 | help |
ced3ce76 DB |
673 | This option enables sideband register access support for Intel SoC |
674 | platforms. On these platforms the IOSF sideband is used in lieu of | |
675 | MSR's for some register accesses, mostly but not limited to thermal | |
676 | and power. Drivers may query the availability of this device to | |
677 | determine if they need the sideband in order to work on these | |
678 | platforms. The sideband is available on the following SoC products. | |
679 | This list is not meant to be exclusive. | |
680 | - BayTrail | |
681 | - Braswell | |
682 | - Quark | |
683 | ||
684 | You should say Y if you are running a kernel on one of these SoC's. | |
685 | ||
ed2226bd DB |
686 | config IOSF_MBI_DEBUG |
687 | bool "Enable IOSF sideband access through debugfs" | |
688 | depends on IOSF_MBI && DEBUG_FS | |
a7f7f624 | 689 | help |
ed2226bd DB |
690 | Select this option to expose the IOSF sideband access registers (MCR, |
691 | MDR, MCRX) through debugfs to write and read register information from | |
692 | different units on the SoC. This is most useful for obtaining device | |
693 | state information for debug and analysis. As this is a general access | |
694 | mechanism, users of this option would have specific knowledge of the | |
695 | device they want to access. | |
696 | ||
697 | If you don't require the option or are in doubt, say N. | |
698 | ||
c5c606d9 RT |
699 | config X86_RDC321X |
700 | bool "RDC R-321x SoC" | |
506f1d07 | 701 | depends on X86_32 |
c5c606d9 RT |
702 | depends on X86_EXTENDED_PLATFORM |
703 | select M486 | |
704 | select X86_REBOOTFIXUPS | |
a7f7f624 | 705 | help |
c5c606d9 RT |
706 | This option is needed for RDC R-321x system-on-chip, also known |
707 | as R-8610-(G). | |
708 | If you don't have one of these chips, you should say N here. | |
709 | ||
e0c7ae37 | 710 | config X86_32_NON_STANDARD |
9c398017 IM |
711 | bool "Support non-standard 32-bit SMP architectures" |
712 | depends on X86_32 && SMP | |
c5c606d9 | 713 | depends on X86_EXTENDED_PLATFORM |
a7f7f624 | 714 | help |
b5660ba7 PA |
715 | This option compiles in the bigsmp and STA2X11 default |
716 | subarchitectures. It is intended for a generic binary | |
717 | kernel. If you select them all, kernel will probe it one by | |
718 | one and will fallback to default. | |
d49c4288 | 719 | |
c5c606d9 | 720 | # Alphabetically sorted list of Non standard 32 bit platforms |
d49c4288 | 721 | |
d949f36f | 722 | config X86_SUPPORTS_MEMORY_FAILURE |
6fc108a0 | 723 | def_bool y |
d949f36f LT |
724 | # MCE code calls memory_failure(): |
725 | depends on X86_MCE | |
726 | # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: | |
d949f36f LT |
727 | # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: |
728 | depends on X86_64 || !SPARSEMEM | |
729 | select ARCH_SUPPORTS_MEMORY_FAILURE | |
d949f36f | 730 | |
83125a3a AR |
731 | config STA2X11 |
732 | bool "STA2X11 Companion Chip Support" | |
733 | depends on X86_32_NON_STANDARD && PCI | |
83125a3a AR |
734 | select SWIOTLB |
735 | select MFD_STA2X11 | |
0145071b | 736 | select GPIOLIB |
a7f7f624 | 737 | help |
83125a3a AR |
738 | This adds support for boards based on the STA2X11 IO-Hub, |
739 | a.k.a. "ConneXt". The chip is used in place of the standard | |
740 | PC chipset, so all "standard" peripherals are missing. If this | |
741 | option is selected the kernel will still be able to boot on | |
742 | standard PC machines. | |
743 | ||
82148d1d S |
744 | config X86_32_IRIS |
745 | tristate "Eurobraille/Iris poweroff module" | |
746 | depends on X86_32 | |
a7f7f624 | 747 | help |
82148d1d S |
748 | The Iris machines from EuroBraille do not have APM or ACPI support |
749 | to shut themselves down properly. A special I/O sequence is | |
750 | needed to do so, which is what this module does at | |
751 | kernel shutdown. | |
752 | ||
753 | This is only for Iris machines from EuroBraille. | |
754 | ||
755 | If unused, say N. | |
756 | ||
ae1e9130 | 757 | config SCHED_OMIT_FRAME_POINTER |
3c2362e6 HH |
758 | def_bool y |
759 | prompt "Single-depth WCHAN output" | |
a87d0914 | 760 | depends on X86 |
a7f7f624 | 761 | help |
506f1d07 SR |
762 | Calculate simpler /proc/<PID>/wchan values. If this option |
763 | is disabled then wchan values will recurse back to the | |
764 | caller function. This provides more accurate wchan values, | |
765 | at the expense of slightly more scheduling overhead. | |
766 | ||
767 | If in doubt, say "Y". | |
768 | ||
6276a074 BP |
769 | menuconfig HYPERVISOR_GUEST |
770 | bool "Linux guest support" | |
a7f7f624 | 771 | help |
6276a074 BP |
772 | Say Y here to enable options for running Linux under various hyper- |
773 | visors. This option enables basic hypervisor detection and platform | |
774 | setup. | |
506f1d07 | 775 | |
6276a074 BP |
776 | If you say N, all options in this submenu will be skipped and |
777 | disabled, and Linux guest support won't be built in. | |
506f1d07 | 778 | |
6276a074 | 779 | if HYPERVISOR_GUEST |
506f1d07 | 780 | |
e61bd94a EPH |
781 | config PARAVIRT |
782 | bool "Enable paravirtualization code" | |
a0e2bf7c | 783 | depends on HAVE_STATIC_CALL |
a7f7f624 | 784 | help |
e61bd94a EPH |
785 | This changes the kernel so it can modify itself when it is run |
786 | under a hypervisor, potentially improving performance significantly | |
787 | over full virtualization. However, when run without a hypervisor | |
788 | the kernel is theoretically slower and slightly larger. | |
789 | ||
c00a280a JG |
790 | config PARAVIRT_XXL |
791 | bool | |
792 | ||
6276a074 BP |
793 | config PARAVIRT_DEBUG |
794 | bool "paravirt-ops debugging" | |
795 | depends on PARAVIRT && DEBUG_KERNEL | |
a7f7f624 | 796 | help |
6276a074 BP |
797 | Enable to debug paravirt_ops internals. Specifically, BUG if |
798 | a paravirt_op is missing when it is called. | |
799 | ||
b4ecc126 JF |
800 | config PARAVIRT_SPINLOCKS |
801 | bool "Paravirtualization layer for spinlocks" | |
6ea30386 | 802 | depends on PARAVIRT && SMP |
a7f7f624 | 803 | help |
b4ecc126 JF |
804 | Paravirtualized spinlocks allow a pvops backend to replace the |
805 | spinlock implementation with something virtualization-friendly | |
806 | (for example, block the virtual CPU rather than spinning). | |
807 | ||
4c4e4f61 R |
808 | It has a minimal impact on native kernels and gives a nice performance |
809 | benefit on paravirtualized KVM / Xen kernels. | |
b4ecc126 | 810 | |
4c4e4f61 | 811 | If you are unsure how to answer this question, answer Y. |
b4ecc126 | 812 | |
ecca2502 ZY |
813 | config X86_HV_CALLBACK_VECTOR |
814 | def_bool n | |
815 | ||
6276a074 | 816 | source "arch/x86/xen/Kconfig" |
7af192c9 | 817 | |
6276a074 BP |
818 | config KVM_GUEST |
819 | bool "KVM Guest support (including kvmclock)" | |
820 | depends on PARAVIRT | |
821 | select PARAVIRT_CLOCK | |
a1c4423b | 822 | select ARCH_CPUIDLE_HALTPOLL |
b1d40575 | 823 | select X86_HV_CALLBACK_VECTOR |
6276a074 | 824 | default y |
a7f7f624 | 825 | help |
6276a074 BP |
826 | This option enables various optimizations for running under the KVM |
827 | hypervisor. It includes a paravirtualized clock, so that instead | |
828 | of relying on a PIT (or probably other) emulation by the | |
829 | underlying device model, the host provides the guest with | |
830 | timing infrastructure such as time of day, and system time | |
506f1d07 | 831 | |
a1c4423b | 832 | config ARCH_CPUIDLE_HALTPOLL |
b03b016f KK |
833 | def_bool n |
834 | prompt "Disable host haltpoll when loading haltpoll driver" | |
835 | help | |
a1c4423b MT |
836 | If virtualized under KVM, disable host haltpoll. |
837 | ||
7733607f MW |
838 | config PVH |
839 | bool "Support for running PVH guests" | |
a7f7f624 | 840 | help |
7733607f MW |
841 | This option enables the PVH entry point for guest virtual machines |
842 | as specified in the x86/HVM direct boot ABI. | |
843 | ||
6276a074 BP |
844 | config PARAVIRT_TIME_ACCOUNTING |
845 | bool "Paravirtual steal time accounting" | |
846 | depends on PARAVIRT | |
a7f7f624 | 847 | help |
6276a074 BP |
848 | Select this option to enable fine granularity task steal time |
849 | accounting. Time spent executing other tasks in parallel with | |
850 | the current vCPU is discounted from the vCPU power. To account for | |
851 | that, there can be a small performance impact. | |
852 | ||
853 | If in doubt, say N here. | |
854 | ||
855 | config PARAVIRT_CLOCK | |
856 | bool | |
97349135 | 857 | |
4a362601 JK |
858 | config JAILHOUSE_GUEST |
859 | bool "Jailhouse non-root cell support" | |
abde587b | 860 | depends on X86_64 && PCI |
87e65d05 | 861 | select X86_PM_TIMER |
a7f7f624 | 862 | help |
4a362601 JK |
863 | This option allows to run Linux as guest in a Jailhouse non-root |
864 | cell. You can leave this option disabled if you only want to start | |
865 | Jailhouse and run Linux afterwards in the root cell. | |
866 | ||
ec7972c9 ZY |
867 | config ACRN_GUEST |
868 | bool "ACRN Guest support" | |
869 | depends on X86_64 | |
498ad393 | 870 | select X86_HV_CALLBACK_VECTOR |
ec7972c9 ZY |
871 | help |
872 | This option allows to run Linux as guest in the ACRN hypervisor. ACRN is | |
873 | a flexible, lightweight reference open-source hypervisor, built with | |
874 | real-time and safety-criticality in mind. It is built for embedded | |
875 | IOT with small footprint and real-time features. More details can be | |
876 | found in https://projectacrn.org/. | |
877 | ||
59bd54a8 KS |
878 | config INTEL_TDX_GUEST |
879 | bool "Intel TDX (Trust Domain Extensions) - Guest Support" | |
880 | depends on X86_64 && CPU_SUP_INTEL | |
881 | depends on X86_X2APIC | |
75d090fd | 882 | depends on EFI_STUB |
41394e33 | 883 | select ARCH_HAS_CC_PLATFORM |
968b4931 | 884 | select X86_MEM_ENCRYPT |
77a512e3 | 885 | select X86_MCE |
75d090fd | 886 | select UNACCEPTED_MEMORY |
59bd54a8 KS |
887 | help |
888 | Support running as a guest under Intel TDX. Without this support, | |
889 | the guest kernel can not boot or run under TDX. | |
890 | TDX includes memory encryption and integrity capabilities | |
891 | which protect the confidentiality and integrity of guest | |
892 | memory contents and CPU state. TDX guests are protected from | |
893 | some attacks from the VMM. | |
894 | ||
758cd94a | 895 | endif # HYPERVISOR_GUEST |
97349135 | 896 | |
506f1d07 SR |
897 | source "arch/x86/Kconfig.cpu" |
898 | ||
899 | config HPET_TIMER | |
3c2362e6 | 900 | def_bool X86_64 |
506f1d07 | 901 | prompt "HPET Timer Support" if X86_32 |
a7f7f624 | 902 | help |
8f9ca475 IM |
903 | Use the IA-PC HPET (High Precision Event Timer) to manage |
904 | time in preference to the PIT and RTC, if a HPET is | |
905 | present. | |
906 | HPET is the next generation timer replacing legacy 8254s. | |
907 | The HPET provides a stable time base on SMP | |
908 | systems, unlike the TSC, but it is more expensive to access, | |
4e7f9df2 MT |
909 | as it is off-chip. The interface used is documented |
910 | in the HPET spec, revision 1. | |
506f1d07 | 911 | |
8f9ca475 IM |
912 | You can safely choose Y here. However, HPET will only be |
913 | activated if the platform and the BIOS support this feature. | |
914 | Otherwise the 8254 will be used for timing services. | |
506f1d07 | 915 | |
8f9ca475 | 916 | Choose N to continue using the legacy 8254 timer. |
506f1d07 SR |
917 | |
918 | config HPET_EMULATE_RTC | |
3c2362e6 | 919 | def_bool y |
3228e1dc | 920 | depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) |
506f1d07 | 921 | |
6a108a14 | 922 | # Mark as expert because too many people got it wrong. |
506f1d07 | 923 | # The code disables itself when not needed. |
7ae9392c TP |
924 | config DMI |
925 | default y | |
cf074402 | 926 | select DMI_SCAN_MACHINE_NON_EFI_FALLBACK |
6a108a14 | 927 | bool "Enable DMI scanning" if EXPERT |
a7f7f624 | 928 | help |
7ae9392c TP |
929 | Enabled scanning of DMI to identify machine quirks. Say Y |
930 | here unless you have verified that your setup is not | |
931 | affected by entries in the DMI blacklist. Required by PNP | |
932 | BIOS code. | |
933 | ||
506f1d07 | 934 | config GART_IOMMU |
38901f1c | 935 | bool "Old AMD GART IOMMU support" |
2f9237d4 | 936 | select DMA_OPS |
a4ce5a48 | 937 | select IOMMU_HELPER |
506f1d07 | 938 | select SWIOTLB |
23ac4ae8 | 939 | depends on X86_64 && PCI && AMD_NB |
a7f7f624 | 940 | help |
ced3c42c IM |
941 | Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron |
942 | GART based hardware IOMMUs. | |
943 | ||
944 | The GART supports full DMA access for devices with 32-bit access | |
945 | limitations, on systems with more than 3 GB. This is usually needed | |
946 | for USB, sound, many IDE/SATA chipsets and some other devices. | |
947 | ||
948 | Newer systems typically have a modern AMD IOMMU, supported via | |
949 | the CONFIG_AMD_IOMMU=y config option. | |
950 | ||
951 | In normal configurations this driver is only active when needed: | |
952 | there's more than 3 GB of memory and the system contains a | |
953 | 32-bit limited device. | |
954 | ||
955 | If unsure, say Y. | |
506f1d07 | 956 | |
8b766b0f MS |
957 | config BOOT_VESA_SUPPORT |
958 | bool | |
959 | help | |
960 | If true, at least one selected framebuffer driver can take advantage | |
961 | of VESA video modes set at an early boot stage via the vga= parameter. | |
506f1d07 | 962 | |
1184dc2f | 963 | config MAXSMP |
ddb0c5a6 | 964 | bool "Enable Maximum number of SMP Processors and NUMA Nodes" |
6ea30386 | 965 | depends on X86_64 && SMP && DEBUG_KERNEL |
36f5101a | 966 | select CPUMASK_OFFSTACK |
a7f7f624 | 967 | help |
ddb0c5a6 | 968 | Enable maximum number of CPUS and NUMA Nodes for this architecture. |
1184dc2f | 969 | If unsure, say N. |
506f1d07 | 970 | |
aec6487e IM |
971 | # |
972 | # The maximum number of CPUs supported: | |
973 | # | |
974 | # The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, | |
975 | # and which can be configured interactively in the | |
976 | # [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. | |
977 | # | |
978 | # The ranges are different on 32-bit and 64-bit kernels, depending on | |
979 | # hardware capabilities and scalability features of the kernel. | |
980 | # | |
981 | # ( If MAXSMP is enabled we just use the highest possible value and disable | |
982 | # interactive configuration. ) | |
983 | # | |
984 | ||
985 | config NR_CPUS_RANGE_BEGIN | |
a0d0bb4d | 986 | int |
aec6487e IM |
987 | default NR_CPUS_RANGE_END if MAXSMP |
988 | default 1 if !SMP | |
989 | default 2 | |
a0d0bb4d | 990 | |
aec6487e | 991 | config NR_CPUS_RANGE_END |
a0d0bb4d | 992 | int |
aec6487e IM |
993 | depends on X86_32 |
994 | default 64 if SMP && X86_BIGSMP | |
995 | default 8 if SMP && !X86_BIGSMP | |
996 | default 1 if !SMP | |
a0d0bb4d | 997 | |
aec6487e | 998 | config NR_CPUS_RANGE_END |
a0d0bb4d | 999 | int |
aec6487e | 1000 | depends on X86_64 |
1edae1ae SW |
1001 | default 8192 if SMP && CPUMASK_OFFSTACK |
1002 | default 512 if SMP && !CPUMASK_OFFSTACK | |
aec6487e | 1003 | default 1 if !SMP |
a0d0bb4d | 1004 | |
aec6487e | 1005 | config NR_CPUS_DEFAULT |
a0d0bb4d RD |
1006 | int |
1007 | depends on X86_32 | |
aec6487e IM |
1008 | default 32 if X86_BIGSMP |
1009 | default 8 if SMP | |
1010 | default 1 if !SMP | |
a0d0bb4d | 1011 | |
aec6487e | 1012 | config NR_CPUS_DEFAULT |
a0d0bb4d RD |
1013 | int |
1014 | depends on X86_64 | |
aec6487e IM |
1015 | default 8192 if MAXSMP |
1016 | default 64 if SMP | |
1017 | default 1 if !SMP | |
a0d0bb4d | 1018 | |
506f1d07 | 1019 | config NR_CPUS |
36f5101a | 1020 | int "Maximum number of CPUs" if SMP && !MAXSMP |
aec6487e IM |
1021 | range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END |
1022 | default NR_CPUS_DEFAULT | |
a7f7f624 | 1023 | help |
506f1d07 | 1024 | This allows you to specify the maximum number of CPUs which this |
bb61ccc7 | 1025 | kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum |
cad14bb9 | 1026 | supported value is 8192, otherwise the maximum value is 512. The |
506f1d07 SR |
1027 | minimum value which makes sense is 2. |
1028 | ||
aec6487e IM |
1029 | This is purely to save memory: each supported CPU adds about 8KB |
1030 | to the kernel image. | |
506f1d07 | 1031 | |
66558b73 TC |
1032 | config SCHED_CLUSTER |
1033 | bool "Cluster scheduler support" | |
1034 | depends on SMP | |
1035 | default y | |
1036 | help | |
1037 | Cluster scheduler support improves the CPU scheduler's decision | |
1038 | making when dealing with machines that have clusters of CPUs. | |
1039 | Cluster usually means a couple of CPUs which are placed closely | |
1040 | by sharing mid-level caches, last-level cache tags or internal | |
1041 | busses. | |
1042 | ||
506f1d07 | 1043 | config SCHED_SMT |
dbe73364 | 1044 | def_bool y if SMP |
506f1d07 SR |
1045 | |
1046 | config SCHED_MC | |
3c2362e6 HH |
1047 | def_bool y |
1048 | prompt "Multi-core scheduler support" | |
c8e56d20 | 1049 | depends on SMP |
a7f7f624 | 1050 | help |
506f1d07 SR |
1051 | Multi-core scheduler support improves the CPU scheduler's decision |
1052 | making when dealing with multi-core CPU chips at a cost of slightly | |
1053 | increased overhead in some places. If unsure say N here. | |
1054 | ||
de966cf4 TC |
1055 | config SCHED_MC_PRIO |
1056 | bool "CPU core priorities scheduler support" | |
0a21fc12 IM |
1057 | depends on SCHED_MC && CPU_SUP_INTEL |
1058 | select X86_INTEL_PSTATE | |
1059 | select CPU_FREQ | |
de966cf4 | 1060 | default y |
a7f7f624 | 1061 | help |
0a21fc12 IM |
1062 | Intel Turbo Boost Max Technology 3.0 enabled CPUs have a |
1063 | core ordering determined at manufacturing time, which allows | |
1064 | certain cores to reach higher turbo frequencies (when running | |
1065 | single threaded workloads) than others. | |
de966cf4 | 1066 | |
0a21fc12 IM |
1067 | Enabling this kernel feature teaches the scheduler about |
1068 | the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the | |
1069 | scheduler's CPU selection logic accordingly, so that higher | |
1070 | overall system performance can be achieved. | |
de966cf4 | 1071 | |
0a21fc12 | 1072 | This feature will have no effect on CPUs without this feature. |
de966cf4 | 1073 | |
0a21fc12 | 1074 | If unsure say Y here. |
5e76b2ab | 1075 | |
30b8b006 | 1076 | config UP_LATE_INIT |
b03b016f KK |
1077 | def_bool y |
1078 | depends on !SMP && X86_LOCAL_APIC | |
30b8b006 | 1079 | |
506f1d07 | 1080 | config X86_UP_APIC |
50849eef JB |
1081 | bool "Local APIC support on uniprocessors" if !PCI_MSI |
1082 | default PCI_MSI | |
38a1dfda | 1083 | depends on X86_32 && !SMP && !X86_32_NON_STANDARD |
a7f7f624 | 1084 | help |
506f1d07 SR |
1085 | A local APIC (Advanced Programmable Interrupt Controller) is an |
1086 | integrated interrupt controller in the CPU. If you have a single-CPU | |
1087 | system which has a processor with a local APIC, you can say Y here to | |
1088 | enable and use it. If you say Y here even though your machine doesn't | |
1089 | have a local APIC, then the kernel will still run with no slowdown at | |
1090 | all. The local APIC supports CPU-generated self-interrupts (timer, | |
1091 | performance counters), and the NMI watchdog which detects hard | |
1092 | lockups. | |
1093 | ||
1094 | config X86_UP_IOAPIC | |
1095 | bool "IO-APIC support on uniprocessors" | |
1096 | depends on X86_UP_APIC | |
a7f7f624 | 1097 | help |
506f1d07 SR |
1098 | An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an |
1099 | SMP-capable replacement for PC-style interrupt controllers. Most | |
1100 | SMP systems and many recent uniprocessor systems have one. | |
1101 | ||
1102 | If you have a single-CPU system with an IO-APIC, you can say Y here | |
1103 | to use it. If you say Y here even though your machine doesn't have | |
1104 | an IO-APIC, then the kernel will still run with no slowdown at all. | |
1105 | ||
1106 | config X86_LOCAL_APIC | |
3c2362e6 | 1107 | def_bool y |
0dbc6078 | 1108 | depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI |
b5dc8e6c | 1109 | select IRQ_DOMAIN_HIERARCHY |
506f1d07 SR |
1110 | |
1111 | config X86_IO_APIC | |
b1da1e71 JB |
1112 | def_bool y |
1113 | depends on X86_LOCAL_APIC || X86_UP_IOAPIC | |
506f1d07 | 1114 | |
41b9eb26 SA |
1115 | config X86_REROUTE_FOR_BROKEN_BOOT_IRQS |
1116 | bool "Reroute for broken boot IRQs" | |
41b9eb26 | 1117 | depends on X86_IO_APIC |
a7f7f624 | 1118 | help |
41b9eb26 SA |
1119 | This option enables a workaround that fixes a source of |
1120 | spurious interrupts. This is recommended when threaded | |
1121 | interrupt handling is used on systems where the generation of | |
1122 | superfluous "boot interrupts" cannot be disabled. | |
1123 | ||
1124 | Some chipsets generate a legacy INTx "boot IRQ" when the IRQ | |
1125 | entry in the chipset's IO-APIC is masked (as, e.g. the RT | |
1126 | kernel does during interrupt handling). On chipsets where this | |
1127 | boot IRQ generation cannot be disabled, this workaround keeps | |
1128 | the original IRQ line masked so that only the equivalent "boot | |
1129 | IRQ" is delivered to the CPUs. The workaround also tells the | |
1130 | kernel to set up the IRQ handler on the boot IRQ line. In this | |
1131 | way only one interrupt is delivered to the kernel. Otherwise | |
1132 | the spurious second interrupt may cause the kernel to bring | |
1133 | down (vital) interrupt lines. | |
1134 | ||
1135 | Only affects "broken" chipsets. Interrupt sharing may be | |
1136 | increased on these systems. | |
1137 | ||
506f1d07 | 1138 | config X86_MCE |
bab9bc65 | 1139 | bool "Machine Check / overheating reporting" |
648ed940 | 1140 | select GENERIC_ALLOCATOR |
e57dbaf7 | 1141 | default y |
a7f7f624 | 1142 | help |
bab9bc65 AK |
1143 | Machine Check support allows the processor to notify the |
1144 | kernel if it detects a problem (e.g. overheating, data corruption). | |
506f1d07 | 1145 | The action the kernel takes depends on the severity of the problem, |
bab9bc65 | 1146 | ranging from warning messages to halting the machine. |
4efc0670 | 1147 | |
5de97c9f TL |
1148 | config X86_MCELOG_LEGACY |
1149 | bool "Support for deprecated /dev/mcelog character device" | |
1150 | depends on X86_MCE | |
a7f7f624 | 1151 | help |
5de97c9f TL |
1152 | Enable support for /dev/mcelog which is needed by the old mcelog |
1153 | userspace logging daemon. Consider switching to the new generation | |
1154 | rasdaemon solution. | |
1155 | ||
506f1d07 | 1156 | config X86_MCE_INTEL |
3c2362e6 HH |
1157 | def_bool y |
1158 | prompt "Intel MCE features" | |
c1ebf835 | 1159 | depends on X86_MCE && X86_LOCAL_APIC |
a7f7f624 | 1160 | help |
758cd94a JH |
1161 | Additional support for intel specific MCE features such as |
1162 | the thermal monitor. | |
506f1d07 SR |
1163 | |
1164 | config X86_MCE_AMD | |
3c2362e6 HH |
1165 | def_bool y |
1166 | prompt "AMD MCE features" | |
f5382de9 | 1167 | depends on X86_MCE && X86_LOCAL_APIC && AMD_NB |
a7f7f624 | 1168 | help |
758cd94a JH |
1169 | Additional support for AMD specific MCE features such as |
1170 | the DRAM Error Threshold. | |
506f1d07 | 1171 | |
4efc0670 | 1172 | config X86_ANCIENT_MCE |
6fc108a0 | 1173 | bool "Support for old Pentium 5 / WinChip machine checks" |
c31d9633 | 1174 | depends on X86_32 && X86_MCE |
a7f7f624 | 1175 | help |
cd13adcc | 1176 | Include support for machine check handling on old Pentium 5 or WinChip |
5065a706 | 1177 | systems. These typically need to be enabled explicitly on the command |
cd13adcc | 1178 | line. |
4efc0670 | 1179 | |
b2762686 AK |
1180 | config X86_MCE_THRESHOLD |
1181 | depends on X86_MCE_AMD || X86_MCE_INTEL | |
6fc108a0 | 1182 | def_bool y |
b2762686 | 1183 | |
ea149b36 | 1184 | config X86_MCE_INJECT |
bc8e80d5 | 1185 | depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS |
ea149b36 | 1186 | tristate "Machine check injector support" |
a7f7f624 | 1187 | help |
ea149b36 AK |
1188 | Provide support for injecting machine checks for testing purposes. |
1189 | If you don't know what a machine check is and you don't do kernel | |
1190 | QA it is safe to say n. | |
1191 | ||
07dc900e | 1192 | source "arch/x86/events/Kconfig" |
e633c65a | 1193 | |
5aef51c3 | 1194 | config X86_LEGACY_VM86 |
1e642812 | 1195 | bool "Legacy VM86 support" |
506f1d07 | 1196 | depends on X86_32 |
a7f7f624 | 1197 | help |
5aef51c3 AL |
1198 | This option allows user programs to put the CPU into V8086 |
1199 | mode, which is an 80286-era approximation of 16-bit real mode. | |
1200 | ||
1201 | Some very old versions of X and/or vbetool require this option | |
1202 | for user mode setting. Similarly, DOSEMU will use it if | |
1203 | available to accelerate real mode DOS programs. However, any | |
1204 | recent version of DOSEMU, X, or vbetool should be fully | |
1205 | functional even without kernel VM86 support, as they will all | |
1e642812 IM |
1206 | fall back to software emulation. Nevertheless, if you are using |
1207 | a 16-bit DOS program where 16-bit performance matters, vm86 | |
1208 | mode might be faster than emulation and you might want to | |
1209 | enable this option. | |
5aef51c3 | 1210 | |
1e642812 IM |
1211 | Note that any app that works on a 64-bit kernel is unlikely to |
1212 | need this option, as 64-bit kernels don't, and can't, support | |
1213 | V8086 mode. This option is also unrelated to 16-bit protected | |
1214 | mode and is not needed to run most 16-bit programs under Wine. | |
5aef51c3 | 1215 | |
1e642812 IM |
1216 | Enabling this option increases the complexity of the kernel |
1217 | and slows down exception handling a tiny bit. | |
5aef51c3 | 1218 | |
1e642812 | 1219 | If unsure, say N here. |
5aef51c3 AL |
1220 | |
1221 | config VM86 | |
b03b016f KK |
1222 | bool |
1223 | default X86_LEGACY_VM86 | |
34273f41 PA |
1224 | |
1225 | config X86_16BIT | |
1226 | bool "Enable support for 16-bit segments" if EXPERT | |
1227 | default y | |
a5b9e5a2 | 1228 | depends on MODIFY_LDT_SYSCALL |
a7f7f624 | 1229 | help |
34273f41 PA |
1230 | This option is required by programs like Wine to run 16-bit |
1231 | protected mode legacy code on x86 processors. Disabling | |
1232 | this option saves about 300 bytes on i386, or around 6K text | |
1233 | plus 16K runtime memory on x86-64, | |
1234 | ||
1235 | config X86_ESPFIX32 | |
1236 | def_bool y | |
1237 | depends on X86_16BIT && X86_32 | |
506f1d07 | 1238 | |
197725de PA |
1239 | config X86_ESPFIX64 |
1240 | def_bool y | |
34273f41 | 1241 | depends on X86_16BIT && X86_64 |
506f1d07 | 1242 | |
1ad83c85 | 1243 | config X86_VSYSCALL_EMULATION |
b03b016f KK |
1244 | bool "Enable vsyscall emulation" if EXPERT |
1245 | default y | |
1246 | depends on X86_64 | |
a7f7f624 | 1247 | help |
758cd94a JH |
1248 | This enables emulation of the legacy vsyscall page. Disabling |
1249 | it is roughly equivalent to booting with vsyscall=none, except | |
1250 | that it will also disable the helpful warning if a program | |
1251 | tries to use a vsyscall. With this option set to N, offending | |
1252 | programs will just segfault, citing addresses of the form | |
1253 | 0xffffffffff600?00. | |
1ad83c85 | 1254 | |
758cd94a JH |
1255 | This option is required by many programs built before 2013, and |
1256 | care should be used even with newer programs if set to N. | |
1ad83c85 | 1257 | |
758cd94a JH |
1258 | Disabling this option saves about 7K of kernel size and |
1259 | possibly 4K of additional runtime pagetable memory. | |
1ad83c85 | 1260 | |
111e7b15 TG |
1261 | config X86_IOPL_IOPERM |
1262 | bool "IOPERM and IOPL Emulation" | |
a24ca997 | 1263 | default y |
a7f7f624 | 1264 | help |
111e7b15 TG |
1265 | This enables the ioperm() and iopl() syscalls which are necessary |
1266 | for legacy applications. | |
1267 | ||
c8137ace TG |
1268 | Legacy IOPL support is an overbroad mechanism which allows user |
1269 | space aside of accessing all 65536 I/O ports also to disable | |
1270 | interrupts. To gain this access the caller needs CAP_SYS_RAWIO | |
1271 | capabilities and permission from potentially active security | |
1272 | modules. | |
1273 | ||
1274 | The emulation restricts the functionality of the syscall to | |
1275 | only allowing the full range I/O port access, but prevents the | |
a24ca997 TG |
1276 | ability to disable interrupts from user space which would be |
1277 | granted if the hardware IOPL mechanism would be used. | |
c8137ace | 1278 | |
506f1d07 SR |
1279 | config TOSHIBA |
1280 | tristate "Toshiba Laptop support" | |
1281 | depends on X86_32 | |
a7f7f624 | 1282 | help |
506f1d07 SR |
1283 | This adds a driver to safely access the System Management Mode of |
1284 | the CPU on Toshiba portables with a genuine Toshiba BIOS. It does | |
1285 | not work on models with a Phoenix BIOS. The System Management Mode | |
1286 | is used to set the BIOS and power saving options on Toshiba portables. | |
1287 | ||
1288 | For information on utilities to make use of this driver see the | |
1289 | Toshiba Linux utilities web site at: | |
1290 | <http://www.buzzard.org.uk/toshiba/>. | |
1291 | ||
1292 | Say Y if you intend to run this kernel on a Toshiba portable. | |
1293 | Say N otherwise. | |
1294 | ||
506f1d07 | 1295 | config X86_REBOOTFIXUPS |
9ba16087 JB |
1296 | bool "Enable X86 board specific fixups for reboot" |
1297 | depends on X86_32 | |
a7f7f624 | 1298 | help |
506f1d07 SR |
1299 | This enables chipset and/or board specific fixups to be done |
1300 | in order to get reboot to work correctly. This is only needed on | |
1301 | some combinations of hardware and BIOS. The symptom, for which | |
1302 | this config is intended, is when reboot ends with a stalled/hung | |
1303 | system. | |
1304 | ||
1305 | Currently, the only fixup is for the Geode machines using | |
5e3a77e9 | 1306 | CS5530A and CS5536 chipsets and the RDC R-321x SoC. |
506f1d07 SR |
1307 | |
1308 | Say Y if you want to enable the fixup. Currently, it's safe to | |
1309 | enable this option even if you don't need it. | |
1310 | Say N otherwise. | |
1311 | ||
1312 | config MICROCODE | |
e6bcfdd7 | 1313 | def_bool y |
80030e3d | 1314 | depends on CPU_SUP_AMD || CPU_SUP_INTEL |
80cc9f10 | 1315 | |
a77a94f8 BP |
1316 | config MICROCODE_LATE_LOADING |
1317 | bool "Late microcode loading (DANGEROUS)" | |
c02f48e0 | 1318 | default n |
506f1d07 | 1319 | depends on MICROCODE |
a7f7f624 | 1320 | help |
a77a94f8 BP |
1321 | Loading microcode late, when the system is up and executing instructions |
1322 | is a tricky business and should be avoided if possible. Just the sequence | |
1323 | of synchronizing all cores and SMT threads is one fragile dance which does | |
1324 | not guarantee that cores might not softlock after the loading. Therefore, | |
1325 | use this at your own risk. Late loading taints the kernel too. | |
506f1d07 SR |
1326 | |
1327 | config X86_MSR | |
1328 | tristate "/dev/cpu/*/msr - Model-specific register support" | |
a7f7f624 | 1329 | help |
506f1d07 SR |
1330 | This device gives privileged processes access to the x86 |
1331 | Model-Specific Registers (MSRs). It is a character device with | |
1332 | major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. | |
1333 | MSR accesses are directed to a specific CPU on multi-processor | |
1334 | systems. | |
1335 | ||
1336 | config X86_CPUID | |
1337 | tristate "/dev/cpu/*/cpuid - CPU information support" | |
a7f7f624 | 1338 | help |
506f1d07 SR |
1339 | This device gives processes access to the x86 CPUID instruction to |
1340 | be executed on a specific processor. It is a character device | |
1341 | with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to | |
1342 | /dev/cpu/31/cpuid. | |
1343 | ||
1344 | choice | |
1345 | prompt "High Memory Support" | |
6fc108a0 | 1346 | default HIGHMEM4G |
506f1d07 SR |
1347 | depends on X86_32 |
1348 | ||
1349 | config NOHIGHMEM | |
1350 | bool "off" | |
a7f7f624 | 1351 | help |
506f1d07 SR |
1352 | Linux can use up to 64 Gigabytes of physical memory on x86 systems. |
1353 | However, the address space of 32-bit x86 processors is only 4 | |
1354 | Gigabytes large. That means that, if you have a large amount of | |
1355 | physical memory, not all of it can be "permanently mapped" by the | |
1356 | kernel. The physical memory that's not permanently mapped is called | |
1357 | "high memory". | |
1358 | ||
1359 | If you are compiling a kernel which will never run on a machine with | |
1360 | more than 1 Gigabyte total physical RAM, answer "off" here (default | |
1361 | choice and suitable for most users). This will result in a "3GB/1GB" | |
1362 | split: 3GB are mapped so that each process sees a 3GB virtual memory | |
1363 | space and the remaining part of the 4GB virtual memory space is used | |
1364 | by the kernel to permanently map as much physical memory as | |
1365 | possible. | |
1366 | ||
1367 | If the machine has between 1 and 4 Gigabytes physical RAM, then | |
1368 | answer "4GB" here. | |
1369 | ||
1370 | If more than 4 Gigabytes is used then answer "64GB" here. This | |
1371 | selection turns Intel PAE (Physical Address Extension) mode on. | |
1372 | PAE implements 3-level paging on IA32 processors. PAE is fully | |
1373 | supported by Linux, PAE mode is implemented on all recent Intel | |
1374 | processors (Pentium Pro and better). NOTE: If you say "64GB" here, | |
1375 | then the kernel will not boot on CPUs that don't support PAE! | |
1376 | ||
1377 | The actual amount of total physical memory will either be | |
1378 | auto detected or can be forced by using a kernel command line option | |
1379 | such as "mem=256M". (Try "man bootparam" or see the documentation of | |
1380 | your boot loader (lilo or loadlin) about how to pass options to the | |
1381 | kernel at boot time.) | |
1382 | ||
1383 | If unsure, say "off". | |
1384 | ||
1385 | config HIGHMEM4G | |
1386 | bool "4GB" | |
a7f7f624 | 1387 | help |
506f1d07 SR |
1388 | Select this if you have a 32-bit processor and between 1 and 4 |
1389 | gigabytes of physical RAM. | |
1390 | ||
1391 | config HIGHMEM64G | |
1392 | bool "64GB" | |
225bac2d | 1393 | depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6 |
506f1d07 | 1394 | select X86_PAE |
a7f7f624 | 1395 | help |
506f1d07 SR |
1396 | Select this if you have a 32-bit processor and more than 4 |
1397 | gigabytes of physical RAM. | |
1398 | ||
1399 | endchoice | |
1400 | ||
1401 | choice | |
6a108a14 | 1402 | prompt "Memory split" if EXPERT |
506f1d07 SR |
1403 | default VMSPLIT_3G |
1404 | depends on X86_32 | |
a7f7f624 | 1405 | help |
506f1d07 SR |
1406 | Select the desired split between kernel and user memory. |
1407 | ||
1408 | If the address range available to the kernel is less than the | |
1409 | physical memory installed, the remaining memory will be available | |
1410 | as "high memory". Accessing high memory is a little more costly | |
1411 | than low memory, as it needs to be mapped into the kernel first. | |
1412 | Note that increasing the kernel address space limits the range | |
1413 | available to user programs, making the address space there | |
1414 | tighter. Selecting anything other than the default 3G/1G split | |
1415 | will also likely make your kernel incompatible with binary-only | |
1416 | kernel modules. | |
1417 | ||
1418 | If you are not absolutely sure what you are doing, leave this | |
1419 | option alone! | |
1420 | ||
1421 | config VMSPLIT_3G | |
1422 | bool "3G/1G user/kernel split" | |
1423 | config VMSPLIT_3G_OPT | |
1424 | depends on !X86_PAE | |
1425 | bool "3G/1G user/kernel split (for full 1G low memory)" | |
1426 | config VMSPLIT_2G | |
1427 | bool "2G/2G user/kernel split" | |
1428 | config VMSPLIT_2G_OPT | |
1429 | depends on !X86_PAE | |
1430 | bool "2G/2G user/kernel split (for full 2G low memory)" | |
1431 | config VMSPLIT_1G | |
1432 | bool "1G/3G user/kernel split" | |
1433 | endchoice | |
1434 | ||
1435 | config PAGE_OFFSET | |
1436 | hex | |
1437 | default 0xB0000000 if VMSPLIT_3G_OPT | |
1438 | default 0x80000000 if VMSPLIT_2G | |
1439 | default 0x78000000 if VMSPLIT_2G_OPT | |
1440 | default 0x40000000 if VMSPLIT_1G | |
1441 | default 0xC0000000 | |
1442 | depends on X86_32 | |
1443 | ||
1444 | config HIGHMEM | |
3c2362e6 | 1445 | def_bool y |
506f1d07 | 1446 | depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) |
506f1d07 SR |
1447 | |
1448 | config X86_PAE | |
9ba16087 | 1449 | bool "PAE (Physical Address Extension) Support" |
506f1d07 | 1450 | depends on X86_32 && !HIGHMEM4G |
d4a451d5 | 1451 | select PHYS_ADDR_T_64BIT |
9d99c712 | 1452 | select SWIOTLB |
a7f7f624 | 1453 | help |
506f1d07 SR |
1454 | PAE is required for NX support, and furthermore enables |
1455 | larger swapspace support for non-overcommit purposes. It | |
1456 | has the cost of more pagetable lookup overhead, and also | |
1457 | consumes more pagetable space per process. | |
1458 | ||
77ef56e4 KS |
1459 | config X86_5LEVEL |
1460 | bool "Enable 5-level page tables support" | |
18ec1eaf | 1461 | default y |
eedb92ab | 1462 | select DYNAMIC_MEMORY_LAYOUT |
162434e7 | 1463 | select SPARSEMEM_VMEMMAP |
77ef56e4 | 1464 | depends on X86_64 |
a7f7f624 | 1465 | help |
77ef56e4 | 1466 | 5-level paging enables access to larger address space: |
54628de6 | 1467 | up to 128 PiB of virtual address space and 4 PiB of |
77ef56e4 KS |
1468 | physical address space. |
1469 | ||
1470 | It will be supported by future Intel CPUs. | |
1471 | ||
6657fca0 KS |
1472 | A kernel with the option enabled can be booted on machines that |
1473 | support 4- or 5-level paging. | |
77ef56e4 | 1474 | |
ff61f079 | 1475 | See Documentation/arch/x86/x86_64/5level-paging.rst for more |
77ef56e4 KS |
1476 | information. |
1477 | ||
1478 | Say N if unsure. | |
1479 | ||
10971ab2 | 1480 | config X86_DIRECT_GBPAGES |
e5008abe | 1481 | def_bool y |
2e1da13f | 1482 | depends on X86_64 |
a7f7f624 | 1483 | help |
10971ab2 IM |
1484 | Certain kernel features effectively disable kernel |
1485 | linear 1 GB mappings (even if the CPU otherwise | |
1486 | supports them), so don't confuse the user by printing | |
1487 | that we have them enabled. | |
9e899816 | 1488 | |
5c280cf6 TG |
1489 | config X86_CPA_STATISTICS |
1490 | bool "Enable statistic for Change Page Attribute" | |
1491 | depends on DEBUG_FS | |
a7f7f624 | 1492 | help |
b75baaf3 | 1493 | Expose statistics about the Change Page Attribute mechanism, which |
a943245a | 1494 | helps to determine the effectiveness of preserving large and huge |
5c280cf6 TG |
1495 | page mappings when mapping protections are changed. |
1496 | ||
20f07a04 KS |
1497 | config X86_MEM_ENCRYPT |
1498 | select ARCH_HAS_FORCE_DMA_UNENCRYPTED | |
1499 | select DYNAMIC_PHYSICAL_MASK | |
20f07a04 KS |
1500 | def_bool n |
1501 | ||
7744ccdb TL |
1502 | config AMD_MEM_ENCRYPT |
1503 | bool "AMD Secure Memory Encryption (SME) support" | |
1504 | depends on X86_64 && CPU_SUP_AMD | |
6c321179 | 1505 | depends on EFI_STUB |
82fef0ad | 1506 | select DMA_COHERENT_POOL |
ce9084ba | 1507 | select ARCH_USE_MEMREMAP_PROT |
597cfe48 | 1508 | select INSTRUCTION_DECODER |
aa5a4611 | 1509 | select ARCH_HAS_CC_PLATFORM |
20f07a04 | 1510 | select X86_MEM_ENCRYPT |
6c321179 | 1511 | select UNACCEPTED_MEMORY |
a7f7f624 | 1512 | help |
7744ccdb TL |
1513 | Say yes to enable support for the encryption of system memory. |
1514 | This requires an AMD processor that supports Secure Memory | |
1515 | Encryption (SME). | |
1516 | ||
1517 | config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT | |
1518 | bool "Activate AMD Secure Memory Encryption (SME) by default" | |
7744ccdb | 1519 | depends on AMD_MEM_ENCRYPT |
a7f7f624 | 1520 | help |
7744ccdb TL |
1521 | Say yes to have system memory encrypted by default if running on |
1522 | an AMD processor that supports Secure Memory Encryption (SME). | |
1523 | ||
1524 | If set to Y, then the encryption of system memory can be | |
1525 | deactivated with the mem_encrypt=off command line option. | |
1526 | ||
1527 | If set to N, then the encryption of system memory can be | |
1528 | activated with the mem_encrypt=on command line option. | |
1529 | ||
506f1d07 SR |
1530 | # Common NUMA Features |
1531 | config NUMA | |
e133f6ea | 1532 | bool "NUMA Memory Allocation and Scheduler Support" |
506f1d07 | 1533 | depends on SMP |
b5660ba7 PA |
1534 | depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) |
1535 | default y if X86_BIGSMP | |
7ecd19cf | 1536 | select USE_PERCPU_NUMA_NODE_ID |
a7f7f624 | 1537 | help |
e133f6ea | 1538 | Enable NUMA (Non-Uniform Memory Access) support. |
fd51b2d7 | 1539 | |
506f1d07 SR |
1540 | The kernel will try to allocate memory used by a CPU on the |
1541 | local memory controller of the CPU and add some more | |
1542 | NUMA awareness to the kernel. | |
1543 | ||
c280ea5e | 1544 | For 64-bit this is recommended if the system is Intel Core i7 |
fd51b2d7 KM |
1545 | (or later), AMD Opteron, or EM64T NUMA. |
1546 | ||
b5660ba7 | 1547 | For 32-bit this is only needed if you boot a 32-bit |
7cf6c945 | 1548 | kernel on a 64-bit NUMA platform. |
fd51b2d7 KM |
1549 | |
1550 | Otherwise, you should say N. | |
506f1d07 | 1551 | |
eec1d4fa | 1552 | config AMD_NUMA |
3c2362e6 HH |
1553 | def_bool y |
1554 | prompt "Old style AMD Opteron NUMA detection" | |
5da0ef9a | 1555 | depends on X86_64 && NUMA && PCI |
a7f7f624 | 1556 | help |
eec1d4fa HR |
1557 | Enable AMD NUMA node topology detection. You should say Y here if |
1558 | you have a multi processor AMD system. This uses an old method to | |
1559 | read the NUMA configuration directly from the builtin Northbridge | |
1560 | of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, | |
1561 | which also takes priority if both are compiled in. | |
506f1d07 SR |
1562 | |
1563 | config X86_64_ACPI_NUMA | |
3c2362e6 HH |
1564 | def_bool y |
1565 | prompt "ACPI NUMA detection" | |
506f1d07 SR |
1566 | depends on X86_64 && NUMA && ACPI && PCI |
1567 | select ACPI_NUMA | |
a7f7f624 | 1568 | help |
506f1d07 SR |
1569 | Enable ACPI SRAT based node topology detection. |
1570 | ||
1571 | config NUMA_EMU | |
1572 | bool "NUMA emulation" | |
1b7e03ef | 1573 | depends on NUMA |
a7f7f624 | 1574 | help |
506f1d07 SR |
1575 | Enable NUMA emulation. A flat machine will be split |
1576 | into virtual nodes when booted with "numa=fake=N", where N is the | |
1577 | number of nodes. This is only useful for debugging. | |
1578 | ||
1579 | config NODES_SHIFT | |
d25e26b6 | 1580 | int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP |
51591e31 DR |
1581 | range 1 10 |
1582 | default "10" if MAXSMP | |
506f1d07 | 1583 | default "6" if X86_64 |
506f1d07 | 1584 | default "3" |
a9ee6cf5 | 1585 | depends on NUMA |
a7f7f624 | 1586 | help |
1184dc2f | 1587 | Specify the maximum number of NUMA Nodes available on the target |
692105b8 | 1588 | system. Increases memory reserved to accommodate various tables. |
506f1d07 | 1589 | |
506f1d07 SR |
1590 | config ARCH_FLATMEM_ENABLE |
1591 | def_bool y | |
3b16651f | 1592 | depends on X86_32 && !NUMA |
506f1d07 | 1593 | |
506f1d07 SR |
1594 | config ARCH_SPARSEMEM_ENABLE |
1595 | def_bool y | |
6ea30386 | 1596 | depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD |
506f1d07 SR |
1597 | select SPARSEMEM_STATIC if X86_32 |
1598 | select SPARSEMEM_VMEMMAP_ENABLE if X86_64 | |
1599 | ||
3b16651f | 1600 | config ARCH_SPARSEMEM_DEFAULT |
6ad57f7f | 1601 | def_bool X86_64 || (NUMA && X86_32) |
3b16651f | 1602 | |
506f1d07 SR |
1603 | config ARCH_SELECT_MEMORY_MODEL |
1604 | def_bool y | |
4eda2bc3 | 1605 | depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE |
506f1d07 SR |
1606 | |
1607 | config ARCH_MEMORY_PROBE | |
a0842b70 | 1608 | bool "Enable sysfs memory/probe interface" |
5c11f00b | 1609 | depends on MEMORY_HOTPLUG |
a0842b70 TK |
1610 | help |
1611 | This option enables a sysfs memory/probe interface for testing. | |
cb1aaebe | 1612 | See Documentation/admin-guide/mm/memory-hotplug.rst for more information. |
a0842b70 | 1613 | If you are unsure how to answer this question, answer N. |
506f1d07 | 1614 | |
3b16651f TH |
1615 | config ARCH_PROC_KCORE_TEXT |
1616 | def_bool y | |
1617 | depends on X86_64 && PROC_KCORE | |
1618 | ||
a29815a3 | 1619 | config ILLEGAL_POINTER_VALUE |
b03b016f KK |
1620 | hex |
1621 | default 0 if X86_32 | |
1622 | default 0xdead000000000000 if X86_64 | |
a29815a3 | 1623 | |
7a67832c DW |
1624 | config X86_PMEM_LEGACY_DEVICE |
1625 | bool | |
1626 | ||
ec776ef6 | 1627 | config X86_PMEM_LEGACY |
7a67832c | 1628 | tristate "Support non-standard NVDIMMs and ADR protected memory" |
9f53f9fa DW |
1629 | depends on PHYS_ADDR_T_64BIT |
1630 | depends on BLK_DEV | |
7a67832c | 1631 | select X86_PMEM_LEGACY_DEVICE |
7b27a862 | 1632 | select NUMA_KEEP_MEMINFO if NUMA |
9f53f9fa | 1633 | select LIBNVDIMM |
ec776ef6 CH |
1634 | help |
1635 | Treat memory marked using the non-standard e820 type of 12 as used | |
1636 | by the Intel Sandy Bridge-EP reference BIOS as protected memory. | |
1637 | The kernel will offer these regions to the 'pmem' driver so | |
1638 | they can be used for persistent storage. | |
1639 | ||
1640 | Say Y if unsure. | |
1641 | ||
506f1d07 SR |
1642 | config HIGHPTE |
1643 | bool "Allocate 3rd-level pagetables from highmem" | |
6fc108a0 | 1644 | depends on HIGHMEM |
a7f7f624 | 1645 | help |
506f1d07 SR |
1646 | The VM uses one page table entry for each page of physical memory. |
1647 | For systems with a lot of RAM, this can be wasteful of precious | |
1648 | low memory. Setting this option will put user-space page table | |
1649 | entries in high memory. | |
1650 | ||
9f077871 | 1651 | config X86_CHECK_BIOS_CORRUPTION |
8f9ca475 | 1652 | bool "Check for low memory corruption" |
a7f7f624 | 1653 | help |
8f9ca475 IM |
1654 | Periodically check for memory corruption in low memory, which |
1655 | is suspected to be caused by BIOS. Even when enabled in the | |
1656 | configuration, it is disabled at runtime. Enable it by | |
1657 | setting "memory_corruption_check=1" on the kernel command | |
1658 | line. By default it scans the low 64k of memory every 60 | |
1659 | seconds; see the memory_corruption_check_size and | |
1660 | memory_corruption_check_period parameters in | |
8c27ceff | 1661 | Documentation/admin-guide/kernel-parameters.rst to adjust this. |
8f9ca475 IM |
1662 | |
1663 | When enabled with the default parameters, this option has | |
1664 | almost no overhead, as it reserves a relatively small amount | |
1665 | of memory and scans it infrequently. It both detects corruption | |
1666 | and prevents it from affecting the running system. | |
1667 | ||
1668 | It is, however, intended as a diagnostic tool; if repeatable | |
1669 | BIOS-originated corruption always affects the same memory, | |
1670 | you can use memmap= to prevent the kernel from using that | |
1671 | memory. | |
9f077871 | 1672 | |
c885df50 | 1673 | config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK |
8f9ca475 | 1674 | bool "Set the default setting of memory_corruption_check" |
c885df50 JF |
1675 | depends on X86_CHECK_BIOS_CORRUPTION |
1676 | default y | |
a7f7f624 | 1677 | help |
8f9ca475 IM |
1678 | Set whether the default state of memory_corruption_check is |
1679 | on or off. | |
c885df50 | 1680 | |
506f1d07 SR |
1681 | config MATH_EMULATION |
1682 | bool | |
a5b9e5a2 | 1683 | depends on MODIFY_LDT_SYSCALL |
87d6021b | 1684 | prompt "Math emulation" if X86_32 && (M486SX || MELAN) |
a7f7f624 | 1685 | help |
506f1d07 SR |
1686 | Linux can emulate a math coprocessor (used for floating point |
1687 | operations) if you don't have one. 486DX and Pentium processors have | |
1688 | a math coprocessor built in, 486SX and 386 do not, unless you added | |
1689 | a 487DX or 387, respectively. (The messages during boot time can | |
1690 | give you some hints here ["man dmesg"].) Everyone needs either a | |
1691 | coprocessor or this emulation. | |
1692 | ||
1693 | If you don't have a math coprocessor, you need to say Y here; if you | |
1694 | say Y here even though you have a coprocessor, the coprocessor will | |
1695 | be used nevertheless. (This behavior can be changed with the kernel | |
1696 | command line option "no387", which comes handy if your coprocessor | |
1697 | is broken. Try "man bootparam" or see the documentation of your boot | |
1698 | loader (lilo or loadlin) about how to pass options to the kernel at | |
1699 | boot time.) This means that it is a good idea to say Y here if you | |
1700 | intend to use this kernel on different machines. | |
1701 | ||
1702 | More information about the internals of the Linux math coprocessor | |
1703 | emulation can be found in <file:arch/x86/math-emu/README>. | |
1704 | ||
1705 | If you are not sure, say Y; apart from resulting in a 66 KB bigger | |
1706 | kernel, it won't hurt. | |
1707 | ||
1708 | config MTRR | |
6fc108a0 | 1709 | def_bool y |
6a108a14 | 1710 | prompt "MTRR (Memory Type Range Register) support" if EXPERT |
a7f7f624 | 1711 | help |
506f1d07 SR |
1712 | On Intel P6 family processors (Pentium Pro, Pentium II and later) |
1713 | the Memory Type Range Registers (MTRRs) may be used to control | |
1714 | processor access to memory ranges. This is most useful if you have | |
1715 | a video (VGA) card on a PCI or AGP bus. Enabling write-combining | |
1716 | allows bus write transfers to be combined into a larger transfer | |
1717 | before bursting over the PCI/AGP bus. This can increase performance | |
1718 | of image write operations 2.5 times or more. Saying Y here creates a | |
1719 | /proc/mtrr file which may be used to manipulate your processor's | |
1720 | MTRRs. Typically the X server should use this. | |
1721 | ||
1722 | This code has a reasonably generic interface so that similar | |
1723 | control registers on other processors can be easily supported | |
1724 | as well: | |
1725 | ||
1726 | The Cyrix 6x86, 6x86MX and M II processors have Address Range | |
1727 | Registers (ARRs) which provide a similar functionality to MTRRs. For | |
1728 | these, the ARRs are used to emulate the MTRRs. | |
1729 | The AMD K6-2 (stepping 8 and above) and K6-3 processors have two | |
1730 | MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing | |
1731 | write-combining. All of these processors are supported by this code | |
1732 | and it makes sense to say Y here if you have one of them. | |
1733 | ||
1734 | Saying Y here also fixes a problem with buggy SMP BIOSes which only | |
1735 | set the MTRRs for the boot CPU and not for the secondary CPUs. This | |
1736 | can lead to all sorts of problems, so it's good to say Y here. | |
1737 | ||
1738 | You can safely say Y even if your machine doesn't have MTRRs, you'll | |
1739 | just add about 9 KB to your kernel. | |
1740 | ||
ff61f079 | 1741 | See <file:Documentation/arch/x86/mtrr.rst> for more information. |
506f1d07 | 1742 | |
95ffa243 | 1743 | config MTRR_SANITIZER |
2ffb3501 | 1744 | def_bool y |
95ffa243 YL |
1745 | prompt "MTRR cleanup support" |
1746 | depends on MTRR | |
a7f7f624 | 1747 | help |
aba3728c TG |
1748 | Convert MTRR layout from continuous to discrete, so X drivers can |
1749 | add writeback entries. | |
95ffa243 | 1750 | |
aba3728c | 1751 | Can be disabled with disable_mtrr_cleanup on the kernel command line. |
692105b8 | 1752 | The largest mtrr entry size for a continuous block can be set with |
aba3728c | 1753 | mtrr_chunk_size. |
95ffa243 | 1754 | |
2ffb3501 | 1755 | If unsure, say Y. |
95ffa243 YL |
1756 | |
1757 | config MTRR_SANITIZER_ENABLE_DEFAULT | |
f5098d62 YL |
1758 | int "MTRR cleanup enable value (0-1)" |
1759 | range 0 1 | |
1760 | default "0" | |
95ffa243 | 1761 | depends on MTRR_SANITIZER |
a7f7f624 | 1762 | help |
f5098d62 | 1763 | Enable mtrr cleanup default value |
95ffa243 | 1764 | |
12031a62 YL |
1765 | config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT |
1766 | int "MTRR cleanup spare reg num (0-7)" | |
1767 | range 0 7 | |
1768 | default "1" | |
1769 | depends on MTRR_SANITIZER | |
a7f7f624 | 1770 | help |
12031a62 | 1771 | mtrr cleanup spare entries default, it can be changed via |
aba3728c | 1772 | mtrr_spare_reg_nr=N on the kernel command line. |
12031a62 | 1773 | |
2e5d9c85 | 1774 | config X86_PAT |
6fc108a0 | 1775 | def_bool y |
6a108a14 | 1776 | prompt "x86 PAT support" if EXPERT |
2a8a2719 | 1777 | depends on MTRR |
a7f7f624 | 1778 | help |
2e5d9c85 | 1779 | Use PAT attributes to setup page level cache control. |
042b78e4 | 1780 | |
2e5d9c85 | 1781 | PATs are the modern equivalents of MTRRs and are much more |
1782 | flexible than MTRRs. | |
1783 | ||
1784 | Say N here if you see bootup problems (boot crash, boot hang, | |
042b78e4 | 1785 | spontaneous reboots) or a non-working video driver. |
2e5d9c85 | 1786 | |
1787 | If unsure, say Y. | |
1788 | ||
46cf98cd VP |
1789 | config ARCH_USES_PG_UNCACHED |
1790 | def_bool y | |
1791 | depends on X86_PAT | |
1792 | ||
b971880f | 1793 | config X86_UMIP |
796ebc81 | 1794 | def_bool y |
b971880f | 1795 | prompt "User Mode Instruction Prevention" if EXPERT |
a7f7f624 | 1796 | help |
b971880f BM |
1797 | User Mode Instruction Prevention (UMIP) is a security feature in |
1798 | some x86 processors. If enabled, a general protection fault is | |
1799 | issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are | |
1800 | executed in user mode. These instructions unnecessarily expose | |
1801 | information about the hardware state. | |
796ebc81 RN |
1802 | |
1803 | The vast majority of applications do not use these instructions. | |
1804 | For the very few that do, software emulation is provided in | |
1805 | specific cases in protected and virtual-8086 modes. Emulated | |
1806 | results are dummy. | |
aa35f896 | 1807 | |
156ff4a5 PZ |
1808 | config CC_HAS_IBT |
1809 | # GCC >= 9 and binutils >= 2.29 | |
1810 | # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 | |
1811 | # Clang/LLVM >= 14 | |
262448f3 NC |
1812 | # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f |
1813 | # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 | |
156ff4a5 | 1814 | def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ |
262448f3 | 1815 | (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ |
156ff4a5 PZ |
1816 | $(as-instr,endbr64) |
1817 | ||
18e66b69 RE |
1818 | config X86_CET |
1819 | def_bool n | |
1820 | help | |
1821 | CET features configured (Shadow stack or IBT) | |
1822 | ||
156ff4a5 PZ |
1823 | config X86_KERNEL_IBT |
1824 | prompt "Indirect Branch Tracking" | |
4fd5f70c | 1825 | def_bool y |
03f16cd0 | 1826 | depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL |
f6a2c2b2 NC |
1827 | # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f |
1828 | depends on !LD_IS_LLD || LLD_VERSION >= 140000 | |
03f16cd0 | 1829 | select OBJTOOL |
18e66b69 | 1830 | select X86_CET |
156ff4a5 PZ |
1831 | help |
1832 | Build the kernel with support for Indirect Branch Tracking, a | |
1833 | hardware support course-grain forward-edge Control Flow Integrity | |
1834 | protection. It enforces that all indirect calls must land on | |
1835 | an ENDBR instruction, as such, the compiler will instrument the | |
1836 | code with them to make this happen. | |
1837 | ||
ed53a0d9 | 1838 | In addition to building the kernel with IBT, seal all functions that |
4cdfc11b | 1839 | are not indirect call targets, avoiding them ever becoming one. |
ed53a0d9 PZ |
1840 | |
1841 | This requires LTO like objtool runs and will slow down the build. It | |
1842 | does significantly reduce the number of ENDBR instructions in the | |
1843 | kernel image. | |
1844 | ||
35e97790 | 1845 | config X86_INTEL_MEMORY_PROTECTION_KEYS |
38f3e775 | 1846 | prompt "Memory Protection Keys" |
35e97790 | 1847 | def_bool y |
284244a9 | 1848 | # Note: only available in 64-bit mode |
38f3e775 | 1849 | depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) |
52c8e601 IM |
1850 | select ARCH_USES_HIGH_VMA_FLAGS |
1851 | select ARCH_HAS_PKEYS | |
a7f7f624 | 1852 | help |
284244a9 DH |
1853 | Memory Protection Keys provides a mechanism for enforcing |
1854 | page-based protections, but without requiring modification of the | |
1855 | page tables when an application changes protection domains. | |
1856 | ||
1eecbcdc | 1857 | For details, see Documentation/core-api/protection-keys.rst |
284244a9 DH |
1858 | |
1859 | If unsure, say y. | |
35e97790 | 1860 | |
db616173 MH |
1861 | choice |
1862 | prompt "TSX enable mode" | |
1863 | depends on CPU_SUP_INTEL | |
1864 | default X86_INTEL_TSX_MODE_OFF | |
1865 | help | |
1866 | Intel's TSX (Transactional Synchronization Extensions) feature | |
1867 | allows to optimize locking protocols through lock elision which | |
1868 | can lead to a noticeable performance boost. | |
1869 | ||
1870 | On the other hand it has been shown that TSX can be exploited | |
1871 | to form side channel attacks (e.g. TAA) and chances are there | |
1872 | will be more of those attacks discovered in the future. | |
1873 | ||
1874 | Therefore TSX is not enabled by default (aka tsx=off). An admin | |
1875 | might override this decision by tsx=on the command line parameter. | |
1876 | Even with TSX enabled, the kernel will attempt to enable the best | |
1877 | possible TAA mitigation setting depending on the microcode available | |
1878 | for the particular machine. | |
1879 | ||
1880 | This option allows to set the default tsx mode between tsx=on, =off | |
1881 | and =auto. See Documentation/admin-guide/kernel-parameters.txt for more | |
1882 | details. | |
1883 | ||
1884 | Say off if not sure, auto if TSX is in use but it should be used on safe | |
1885 | platforms or on if TSX is in use and the security aspect of tsx is not | |
1886 | relevant. | |
1887 | ||
1888 | config X86_INTEL_TSX_MODE_OFF | |
1889 | bool "off" | |
1890 | help | |
1891 | TSX is disabled if possible - equals to tsx=off command line parameter. | |
1892 | ||
1893 | config X86_INTEL_TSX_MODE_ON | |
1894 | bool "on" | |
1895 | help | |
1896 | TSX is always enabled on TSX capable HW - equals the tsx=on command | |
1897 | line parameter. | |
1898 | ||
1899 | config X86_INTEL_TSX_MODE_AUTO | |
1900 | bool "auto" | |
1901 | help | |
1902 | TSX is enabled on TSX capable HW that is believed to be safe against | |
1903 | side channel attacks- equals the tsx=auto command line parameter. | |
1904 | endchoice | |
1905 | ||
e7e05452 SC |
1906 | config X86_SGX |
1907 | bool "Software Guard eXtensions (SGX)" | |
b8d1d163 | 1908 | depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC |
e7e05452 SC |
1909 | depends on CRYPTO=y |
1910 | depends on CRYPTO_SHA256=y | |
e7e05452 | 1911 | select MMU_NOTIFIER |
901ddbb9 | 1912 | select NUMA_KEEP_MEMINFO if NUMA |
40e0e784 | 1913 | select XARRAY_MULTI |
e7e05452 SC |
1914 | help |
1915 | Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions | |
1916 | that can be used by applications to set aside private regions of code | |
1917 | and data, referred to as enclaves. An enclave's private memory can | |
1918 | only be accessed by code running within the enclave. Accesses from | |
1919 | outside the enclave, including other enclaves, are disallowed by | |
1920 | hardware. | |
1921 | ||
1922 | If unsure, say N. | |
1923 | ||
18e66b69 RE |
1924 | config X86_USER_SHADOW_STACK |
1925 | bool "X86 userspace shadow stack" | |
1926 | depends on AS_WRUSS | |
1927 | depends on X86_64 | |
1928 | select ARCH_USES_HIGH_VMA_FLAGS | |
1929 | select X86_CET | |
1930 | help | |
1931 | Shadow stack protection is a hardware feature that detects function | |
1932 | return address corruption. This helps mitigate ROP attacks. | |
1933 | Applications must be enabled to use it, and old userspace does not | |
1934 | get protection "for free". | |
1935 | ||
1936 | CPUs supporting shadow stacks were first released in 2020. | |
1937 | ||
54acee60 | 1938 | See Documentation/arch/x86/shstk.rst for more information. |
18e66b69 RE |
1939 | |
1940 | If unsure, say N. | |
1941 | ||
506f1d07 | 1942 | config EFI |
9ba16087 | 1943 | bool "EFI runtime service support" |
5b83683f | 1944 | depends on ACPI |
f6ce5002 | 1945 | select UCS2_STRING |
022ee6c5 | 1946 | select EFI_RUNTIME_WRAPPERS |
1ff2fc02 | 1947 | select ARCH_USE_MEMREMAP_PROT |
aba7e066 | 1948 | select EFI_RUNTIME_MAP if KEXEC_CORE |
a7f7f624 | 1949 | help |
8f9ca475 IM |
1950 | This enables the kernel to use EFI runtime services that are |
1951 | available (such as the EFI variable services). | |
506f1d07 | 1952 | |
8f9ca475 IM |
1953 | This option is only useful on systems that have EFI firmware. |
1954 | In addition, you should use the latest ELILO loader available | |
1955 | at <http://elilo.sourceforge.net> in order to take advantage | |
1956 | of EFI runtime services. However, even with this option, the | |
1957 | resultant kernel should continue to boot on existing non-EFI | |
1958 | platforms. | |
506f1d07 | 1959 | |
291f3632 | 1960 | config EFI_STUB |
8f24f8c2 | 1961 | bool "EFI stub support" |
c6dbd3e5 | 1962 | depends on EFI |
8f24f8c2 | 1963 | select RELOCATABLE |
a7f7f624 | 1964 | help |
8f24f8c2 | 1965 | This kernel feature allows a bzImage to be loaded directly |
291f3632 MF |
1966 | by EFI firmware without the use of a bootloader. |
1967 | ||
4f4cfa6c | 1968 | See Documentation/admin-guide/efi-stub.rst for more information. |
0c759662 | 1969 | |
cc3fdda2 AB |
1970 | config EFI_HANDOVER_PROTOCOL |
1971 | bool "EFI handover protocol (DEPRECATED)" | |
1972 | depends on EFI_STUB | |
1973 | default y | |
1974 | help | |
1975 | Select this in order to include support for the deprecated EFI | |
1976 | handover protocol, which defines alternative entry points into the | |
1977 | EFI stub. This is a practice that has no basis in the UEFI | |
1978 | specification, and requires a priori knowledge on the part of the | |
1979 | bootloader about Linux/x86 specific ways of passing the command line | |
1980 | and initrd, and where in memory those assets may be loaded. | |
1981 | ||
1982 | If in doubt, say Y. Even though the corresponding support is not | |
1983 | present in upstream GRUB or other bootloaders, most distros build | |
1984 | GRUB with numerous downstream patches applied, and may rely on the | |
1985 | handover protocol as as result. | |
1986 | ||
7d453eee MF |
1987 | config EFI_MIXED |
1988 | bool "EFI mixed-mode support" | |
1989 | depends on EFI_STUB && X86_64 | |
a7f7f624 | 1990 | help |
758cd94a JH |
1991 | Enabling this feature allows a 64-bit kernel to be booted |
1992 | on a 32-bit firmware, provided that your CPU supports 64-bit | |
1993 | mode. | |
7d453eee | 1994 | |
758cd94a JH |
1995 | Note that it is not possible to boot a mixed-mode enabled |
1996 | kernel via the EFI boot stub - a bootloader that supports | |
1997 | the EFI handover protocol must be used. | |
7d453eee | 1998 | |
758cd94a | 1999 | If unsure, say N. |
7d453eee | 2000 | |
4059ba65 AB |
2001 | config EFI_FAKE_MEMMAP |
2002 | bool "Enable EFI fake memory map" | |
2003 | depends on EFI | |
2004 | help | |
2005 | Saying Y here will enable "efi_fake_mem" boot option. By specifying | |
2006 | this parameter, you can add arbitrary attribute to specific memory | |
2007 | range by updating original (firmware provided) EFI memmap. This is | |
2008 | useful for debugging of EFI memmap related feature, e.g., Address | |
2009 | Range Mirroring feature. | |
2010 | ||
2011 | config EFI_MAX_FAKE_MEM | |
2012 | int "maximum allowable number of ranges in efi_fake_mem boot option" | |
2013 | depends on EFI_FAKE_MEMMAP | |
2014 | range 1 128 | |
2015 | default 8 | |
2016 | help | |
2017 | Maximum allowable number of ranges in efi_fake_mem boot option. | |
2018 | Ranges can be set up to this value using comma-separated list. | |
2019 | The default value is 8. | |
2020 | ||
1fff234d AB |
2021 | config EFI_RUNTIME_MAP |
2022 | bool "Export EFI runtime maps to sysfs" if EXPERT | |
2023 | depends on EFI | |
1fff234d AB |
2024 | help |
2025 | Export EFI runtime memory regions to /sys/firmware/efi/runtime-map. | |
2026 | That memory map is required by the 2nd kernel to set up EFI virtual | |
2027 | mappings after kexec, but can also be used for debugging purposes. | |
2028 | ||
2029 | See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map. | |
2030 | ||
8636a1f9 | 2031 | source "kernel/Kconfig.hz" |
506f1d07 | 2032 | |
6af51380 ED |
2033 | config ARCH_SUPPORTS_KEXEC |
2034 | def_bool y | |
74ca317c | 2035 | |
6af51380 ED |
2036 | config ARCH_SUPPORTS_KEXEC_FILE |
2037 | def_bool X86_64 && CRYPTO && CRYPTO_SHA256 | |
b799a09f | 2038 | |
6af51380 ED |
2039 | config ARCH_SELECTS_KEXEC_FILE |
2040 | def_bool y | |
74ca317c | 2041 | depends on KEXEC_FILE |
6af51380 | 2042 | select HAVE_IMA_KEXEC if IMA |
d8eb8940 | 2043 | |
e6265fe7 | 2044 | config ARCH_SUPPORTS_KEXEC_PURGATORY |
6af51380 | 2045 | def_bool KEXEC_FILE |
99d5cadf | 2046 | |
6af51380 ED |
2047 | config ARCH_SUPPORTS_KEXEC_SIG |
2048 | def_bool y | |
8e7d8381 | 2049 | |
6af51380 ED |
2050 | config ARCH_SUPPORTS_KEXEC_SIG_FORCE |
2051 | def_bool y | |
99d5cadf | 2052 | |
6af51380 ED |
2053 | config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG |
2054 | def_bool y | |
8e7d8381 | 2055 | |
6af51380 ED |
2056 | config ARCH_SUPPORTS_KEXEC_JUMP |
2057 | def_bool y | |
506f1d07 | 2058 | |
6af51380 ED |
2059 | config ARCH_SUPPORTS_CRASH_DUMP |
2060 | def_bool X86_64 || (X86_32 && HIGHMEM) | |
3ab83521 | 2061 | |
ea53ad9c ED |
2062 | config ARCH_SUPPORTS_CRASH_HOTPLUG |
2063 | def_bool y | |
3ab83521 | 2064 | |
506f1d07 | 2065 | config PHYSICAL_START |
6a108a14 | 2066 | hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) |
ceefccc9 | 2067 | default "0x1000000" |
a7f7f624 | 2068 | help |
506f1d07 SR |
2069 | This gives the physical address where the kernel is loaded. |
2070 | ||
2071 | If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then | |
2072 | bzImage will decompress itself to above physical address and | |
2073 | run from there. Otherwise, bzImage will run from the address where | |
2074 | it has been loaded by the boot loader and will ignore above physical | |
2075 | address. | |
2076 | ||
2077 | In normal kdump cases one does not have to set/change this option | |
2078 | as now bzImage can be compiled as a completely relocatable image | |
2079 | (CONFIG_RELOCATABLE=y) and be used to load and run from a different | |
2080 | address. This option is mainly useful for the folks who don't want | |
2081 | to use a bzImage for capturing the crash dump and want to use a | |
2082 | vmlinux instead. vmlinux is not relocatable hence a kernel needs | |
2083 | to be specifically compiled to run from a specific memory area | |
2084 | (normally a reserved region) and this option comes handy. | |
2085 | ||
ceefccc9 PA |
2086 | So if you are using bzImage for capturing the crash dump, |
2087 | leave the value here unchanged to 0x1000000 and set | |
2088 | CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux | |
2089 | for capturing the crash dump change this value to start of | |
2090 | the reserved region. In other words, it can be set based on | |
2091 | the "X" value as specified in the "crashkernel=YM@XM" | |
2092 | command line boot parameter passed to the panic-ed | |
330d4810 | 2093 | kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst |
ceefccc9 | 2094 | for more details about crash dumps. |
506f1d07 SR |
2095 | |
2096 | Usage of bzImage for capturing the crash dump is recommended as | |
2097 | one does not have to build two kernels. Same kernel can be used | |
2098 | as production kernel and capture kernel. Above option should have | |
2099 | gone away after relocatable bzImage support is introduced. But it | |
2100 | is present because there are users out there who continue to use | |
2101 | vmlinux for dump capture. This option should go away down the | |
2102 | line. | |
2103 | ||
2104 | Don't change this unless you know what you are doing. | |
2105 | ||
2106 | config RELOCATABLE | |
26717808 PA |
2107 | bool "Build a relocatable kernel" |
2108 | default y | |
a7f7f624 | 2109 | help |
506f1d07 SR |
2110 | This builds a kernel image that retains relocation information |
2111 | so it can be loaded someplace besides the default 1MB. | |
2112 | The relocations tend to make the kernel binary about 10% larger, | |
2113 | but are discarded at runtime. | |
2114 | ||
2115 | One use is for the kexec on panic case where the recovery kernel | |
2116 | must live at a different physical address than the primary | |
2117 | kernel. | |
2118 | ||
2119 | Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address | |
2120 | it has been loaded at and the compile time physical address | |
8ab3820f | 2121 | (CONFIG_PHYSICAL_START) is used as the minimum location. |
506f1d07 | 2122 | |
8ab3820f | 2123 | config RANDOMIZE_BASE |
e8581e3d | 2124 | bool "Randomize the address of the kernel image (KASLR)" |
8ab3820f | 2125 | depends on RELOCATABLE |
6807c846 | 2126 | default y |
a7f7f624 | 2127 | help |
e8581e3d BH |
2128 | In support of Kernel Address Space Layout Randomization (KASLR), |
2129 | this randomizes the physical address at which the kernel image | |
2130 | is decompressed and the virtual address where the kernel | |
2131 | image is mapped, as a security feature that deters exploit | |
2132 | attempts relying on knowledge of the location of kernel | |
2133 | code internals. | |
2134 | ||
ed9f007e KC |
2135 | On 64-bit, the kernel physical and virtual addresses are |
2136 | randomized separately. The physical address will be anywhere | |
2137 | between 16MB and the top of physical memory (up to 64TB). The | |
2138 | virtual address will be randomized from 16MB up to 1GB (9 bits | |
2139 | of entropy). Note that this also reduces the memory space | |
2140 | available to kernel modules from 1.5GB to 1GB. | |
2141 | ||
2142 | On 32-bit, the kernel physical and virtual addresses are | |
2143 | randomized together. They will be randomized from 16MB up to | |
2144 | 512MB (8 bits of entropy). | |
e8581e3d BH |
2145 | |
2146 | Entropy is generated using the RDRAND instruction if it is | |
2147 | supported. If RDTSC is supported, its value is mixed into | |
2148 | the entropy pool as well. If neither RDRAND nor RDTSC are | |
ed9f007e KC |
2149 | supported, then entropy is read from the i8254 timer. The |
2150 | usable entropy is limited by the kernel being built using | |
2151 | 2GB addressing, and that PHYSICAL_ALIGN must be at a | |
2152 | minimum of 2MB. As a result, only 10 bits of entropy are | |
2153 | theoretically possible, but the implementations are further | |
2154 | limited due to memory layouts. | |
e8581e3d | 2155 | |
6807c846 | 2156 | If unsure, say Y. |
8ab3820f KC |
2157 | |
2158 | # Relocation on x86 needs some additional build support | |
845adf72 PA |
2159 | config X86_NEED_RELOCS |
2160 | def_bool y | |
8ab3820f | 2161 | depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) |
845adf72 | 2162 | |
506f1d07 | 2163 | config PHYSICAL_ALIGN |
a0215061 | 2164 | hex "Alignment value to which kernel should be aligned" |
8ab3820f | 2165 | default "0x200000" |
a0215061 KC |
2166 | range 0x2000 0x1000000 if X86_32 |
2167 | range 0x200000 0x1000000 if X86_64 | |
a7f7f624 | 2168 | help |
506f1d07 SR |
2169 | This value puts the alignment restrictions on physical address |
2170 | where kernel is loaded and run from. Kernel is compiled for an | |
2171 | address which meets above alignment restriction. | |
2172 | ||
2173 | If bootloader loads the kernel at a non-aligned address and | |
2174 | CONFIG_RELOCATABLE is set, kernel will move itself to nearest | |
2175 | address aligned to above value and run from there. | |
2176 | ||
2177 | If bootloader loads the kernel at a non-aligned address and | |
2178 | CONFIG_RELOCATABLE is not set, kernel will ignore the run time | |
2179 | load address and decompress itself to the address it has been | |
2180 | compiled for and run from there. The address for which kernel is | |
2181 | compiled already meets above alignment restrictions. Hence the | |
2182 | end result is that kernel runs from a physical address meeting | |
2183 | above alignment restrictions. | |
2184 | ||
a0215061 KC |
2185 | On 32-bit this value must be a multiple of 0x2000. On 64-bit |
2186 | this value must be a multiple of 0x200000. | |
2187 | ||
506f1d07 SR |
2188 | Don't change this unless you know what you are doing. |
2189 | ||
eedb92ab KS |
2190 | config DYNAMIC_MEMORY_LAYOUT |
2191 | bool | |
a7f7f624 | 2192 | help |
eedb92ab KS |
2193 | This option makes base addresses of vmalloc and vmemmap as well as |
2194 | __PAGE_OFFSET movable during boot. | |
2195 | ||
0483e1fa TG |
2196 | config RANDOMIZE_MEMORY |
2197 | bool "Randomize the kernel memory sections" | |
2198 | depends on X86_64 | |
2199 | depends on RANDOMIZE_BASE | |
eedb92ab | 2200 | select DYNAMIC_MEMORY_LAYOUT |
0483e1fa | 2201 | default RANDOMIZE_BASE |
a7f7f624 | 2202 | help |
758cd94a JH |
2203 | Randomizes the base virtual address of kernel memory sections |
2204 | (physical memory mapping, vmalloc & vmemmap). This security feature | |
2205 | makes exploits relying on predictable memory locations less reliable. | |
0483e1fa | 2206 | |
758cd94a JH |
2207 | The order of allocations remains unchanged. Entropy is generated in |
2208 | the same way as RANDOMIZE_BASE. Current implementation in the optimal | |
2209 | configuration have in average 30,000 different possible virtual | |
2210 | addresses for each memory section. | |
0483e1fa | 2211 | |
758cd94a | 2212 | If unsure, say Y. |
0483e1fa | 2213 | |
90397a41 TG |
2214 | config RANDOMIZE_MEMORY_PHYSICAL_PADDING |
2215 | hex "Physical memory mapping padding" if EXPERT | |
2216 | depends on RANDOMIZE_MEMORY | |
2217 | default "0xa" if MEMORY_HOTPLUG | |
2218 | default "0x0" | |
2219 | range 0x1 0x40 if MEMORY_HOTPLUG | |
2220 | range 0x0 0x40 | |
a7f7f624 | 2221 | help |
758cd94a JH |
2222 | Define the padding in terabytes added to the existing physical |
2223 | memory size during kernel memory randomization. It is useful | |
2224 | for memory hotplug support but reduces the entropy available for | |
2225 | address randomization. | |
90397a41 | 2226 | |
758cd94a | 2227 | If unsure, leave at the default value. |
90397a41 | 2228 | |
6449dcb0 KS |
2229 | config ADDRESS_MASKING |
2230 | bool "Linear Address Masking support" | |
2231 | depends on X86_64 | |
2232 | help | |
2233 | Linear Address Masking (LAM) modifies the checking that is applied | |
2234 | to 64-bit linear addresses, allowing software to use of the | |
2235 | untranslated address bits for metadata. | |
2236 | ||
2237 | The capability can be used for efficient address sanitizers (ASAN) | |
2238 | implementation and for optimizations in JITs. | |
2239 | ||
506f1d07 | 2240 | config HOTPLUG_CPU |
bebd024e | 2241 | def_bool y |
40b31360 | 2242 | depends on SMP |
506f1d07 SR |
2243 | |
2244 | config COMPAT_VDSO | |
b0b49f26 AL |
2245 | def_bool n |
2246 | prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" | |
953fee1d | 2247 | depends on COMPAT_32 |
a7f7f624 | 2248 | help |
b0b49f26 AL |
2249 | Certain buggy versions of glibc will crash if they are |
2250 | presented with a 32-bit vDSO that is not mapped at the address | |
2251 | indicated in its segment table. | |
e84446de | 2252 | |
b0b49f26 AL |
2253 | The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a |
2254 | and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and | |
2255 | 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is | |
2256 | the only released version with the bug, but OpenSUSE 9 | |
2257 | contains a buggy "glibc 2.3.2". | |
506f1d07 | 2258 | |
b0b49f26 AL |
2259 | The symptom of the bug is that everything crashes on startup, saying: |
2260 | dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! | |
2261 | ||
2262 | Saying Y here changes the default value of the vdso32 boot | |
2263 | option from 1 to 0, which turns off the 32-bit vDSO entirely. | |
2264 | This works around the glibc bug but hurts performance. | |
2265 | ||
2266 | If unsure, say N: if you are compiling your own kernel, you | |
2267 | are unlikely to be using a buggy version of glibc. | |
506f1d07 | 2268 | |
3dc33bd3 KC |
2269 | choice |
2270 | prompt "vsyscall table for legacy applications" | |
2271 | depends on X86_64 | |
625b7b7f | 2272 | default LEGACY_VSYSCALL_XONLY |
3dc33bd3 KC |
2273 | help |
2274 | Legacy user code that does not know how to find the vDSO expects | |
2275 | to be able to issue three syscalls by calling fixed addresses in | |
2276 | kernel space. Since this location is not randomized with ASLR, | |
2277 | it can be used to assist security vulnerability exploitation. | |
2278 | ||
2279 | This setting can be changed at boot time via the kernel command | |
bf00745e AL |
2280 | line parameter vsyscall=[emulate|xonly|none]. Emulate mode |
2281 | is deprecated and can only be enabled using the kernel command | |
2282 | line. | |
3dc33bd3 KC |
2283 | |
2284 | On a system with recent enough glibc (2.14 or newer) and no | |
2285 | static binaries, you can say None without a performance penalty | |
2286 | to improve security. | |
2287 | ||
bd49e16e | 2288 | If unsure, select "Emulate execution only". |
3dc33bd3 | 2289 | |
bd49e16e AL |
2290 | config LEGACY_VSYSCALL_XONLY |
2291 | bool "Emulate execution only" | |
2292 | help | |
2293 | The kernel traps and emulates calls into the fixed vsyscall | |
2294 | address mapping and does not allow reads. This | |
2295 | configuration is recommended when userspace might use the | |
2296 | legacy vsyscall area but support for legacy binary | |
2297 | instrumentation of legacy code is not needed. It mitigates | |
2298 | certain uses of the vsyscall area as an ASLR-bypassing | |
2299 | buffer. | |
3dc33bd3 KC |
2300 | |
2301 | config LEGACY_VSYSCALL_NONE | |
2302 | bool "None" | |
2303 | help | |
2304 | There will be no vsyscall mapping at all. This will | |
2305 | eliminate any risk of ASLR bypass due to the vsyscall | |
2306 | fixed address mapping. Attempts to use the vsyscalls | |
2307 | will be reported to dmesg, so that either old or | |
2308 | malicious userspace programs can be identified. | |
2309 | ||
2310 | endchoice | |
2311 | ||
516cbf37 TB |
2312 | config CMDLINE_BOOL |
2313 | bool "Built-in kernel command line" | |
a7f7f624 | 2314 | help |
516cbf37 TB |
2315 | Allow for specifying boot arguments to the kernel at |
2316 | build time. On some systems (e.g. embedded ones), it is | |
2317 | necessary or convenient to provide some or all of the | |
2318 | kernel boot arguments with the kernel itself (that is, | |
2319 | to not rely on the boot loader to provide them.) | |
2320 | ||
2321 | To compile command line arguments into the kernel, | |
2322 | set this option to 'Y', then fill in the | |
69711ca1 | 2323 | boot arguments in CONFIG_CMDLINE. |
516cbf37 TB |
2324 | |
2325 | Systems with fully functional boot loaders (i.e. non-embedded) | |
2326 | should leave this option set to 'N'. | |
2327 | ||
2328 | config CMDLINE | |
2329 | string "Built-in kernel command string" | |
2330 | depends on CMDLINE_BOOL | |
2331 | default "" | |
a7f7f624 | 2332 | help |
516cbf37 TB |
2333 | Enter arguments here that should be compiled into the kernel |
2334 | image and used at boot time. If the boot loader provides a | |
2335 | command line at boot time, it is appended to this string to | |
2336 | form the full kernel command line, when the system boots. | |
2337 | ||
2338 | However, you can use the CONFIG_CMDLINE_OVERRIDE option to | |
2339 | change this behavior. | |
2340 | ||
2341 | In most cases, the command line (whether built-in or provided | |
2342 | by the boot loader) should specify the device for the root | |
2343 | file system. | |
2344 | ||
2345 | config CMDLINE_OVERRIDE | |
2346 | bool "Built-in command line overrides boot loader arguments" | |
645e6466 | 2347 | depends on CMDLINE_BOOL && CMDLINE != "" |
a7f7f624 | 2348 | help |
516cbf37 TB |
2349 | Set this option to 'Y' to have the kernel ignore the boot loader |
2350 | command line, and use ONLY the built-in command line. | |
2351 | ||
2352 | This is used to work around broken boot loaders. This should | |
2353 | be set to 'N' under normal conditions. | |
2354 | ||
a5b9e5a2 AL |
2355 | config MODIFY_LDT_SYSCALL |
2356 | bool "Enable the LDT (local descriptor table)" if EXPERT | |
2357 | default y | |
a7f7f624 | 2358 | help |
a5b9e5a2 AL |
2359 | Linux can allow user programs to install a per-process x86 |
2360 | Local Descriptor Table (LDT) using the modify_ldt(2) system | |
2361 | call. This is required to run 16-bit or segmented code such as | |
2362 | DOSEMU or some Wine programs. It is also used by some very old | |
2363 | threading libraries. | |
2364 | ||
2365 | Enabling this feature adds a small amount of overhead to | |
2366 | context switches and increases the low-level kernel attack | |
2367 | surface. Disabling it removes the modify_ldt(2) system call. | |
2368 | ||
2369 | Saying 'N' here may make sense for embedded or server kernels. | |
2370 | ||
3aac3ebe TG |
2371 | config STRICT_SIGALTSTACK_SIZE |
2372 | bool "Enforce strict size checking for sigaltstack" | |
2373 | depends on DYNAMIC_SIGFRAME | |
2374 | help | |
2375 | For historical reasons MINSIGSTKSZ is a constant which became | |
2376 | already too small with AVX512 support. Add a mechanism to | |
2377 | enforce strict checking of the sigaltstack size against the | |
2378 | real size of the FPU frame. This option enables the check | |
2379 | by default. It can also be controlled via the kernel command | |
2380 | line option 'strict_sas_size' independent of this config | |
2381 | switch. Enabling it might break existing applications which | |
2382 | allocate a too small sigaltstack but 'work' because they | |
2383 | never get a signal delivered. | |
2384 | ||
2385 | Say 'N' unless you want to really enforce this check. | |
2386 | ||
b700e7f0 SJ |
2387 | source "kernel/livepatch/Kconfig" |
2388 | ||
506f1d07 SR |
2389 | endmenu |
2390 | ||
f43b9876 PZ |
2391 | config CC_HAS_SLS |
2392 | def_bool $(cc-option,-mharden-sls=all) | |
2393 | ||
2394 | config CC_HAS_RETURN_THUNK | |
2395 | def_bool $(cc-option,-mfunction-return=thunk-extern) | |
2396 | ||
bea75b33 TG |
2397 | config CC_HAS_ENTRY_PADDING |
2398 | def_bool $(cc-option,-fpatchable-function-entry=16,16) | |
2399 | ||
2400 | config FUNCTION_PADDING_CFI | |
2401 | int | |
2402 | default 59 if FUNCTION_ALIGNMENT_64B | |
2403 | default 27 if FUNCTION_ALIGNMENT_32B | |
2404 | default 11 if FUNCTION_ALIGNMENT_16B | |
2405 | default 3 if FUNCTION_ALIGNMENT_8B | |
2406 | default 0 | |
2407 | ||
2408 | # Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG | |
2409 | # except Kconfig can't do arithmetic :/ | |
2410 | config FUNCTION_PADDING_BYTES | |
2411 | int | |
2412 | default FUNCTION_PADDING_CFI if CFI_CLANG | |
2413 | default FUNCTION_ALIGNMENT | |
2414 | ||
931ab636 PZ |
2415 | config CALL_PADDING |
2416 | def_bool n | |
2417 | depends on CC_HAS_ENTRY_PADDING && OBJTOOL | |
2418 | select FUNCTION_ALIGNMENT_16B | |
2419 | ||
2420 | config FINEIBT | |
2421 | def_bool y | |
2422 | depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE | |
2423 | select CALL_PADDING | |
2424 | ||
8f7c0d8b TG |
2425 | config HAVE_CALL_THUNKS |
2426 | def_bool y | |
bea75b33 | 2427 | depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL |
8f7c0d8b TG |
2428 | |
2429 | config CALL_THUNKS | |
2430 | def_bool n | |
931ab636 | 2431 | select CALL_PADDING |
8f7c0d8b | 2432 | |
b341b20d PZ |
2433 | config PREFIX_SYMBOLS |
2434 | def_bool y | |
931ab636 | 2435 | depends on CALL_PADDING && !CFI_CLANG |
b341b20d | 2436 | |
f43b9876 PZ |
2437 | menuconfig SPECULATION_MITIGATIONS |
2438 | bool "Mitigations for speculative execution vulnerabilities" | |
2439 | default y | |
2440 | help | |
2441 | Say Y here to enable options which enable mitigations for | |
2442 | speculative execution hardware vulnerabilities. | |
2443 | ||
2444 | If you say N, all mitigations will be disabled. You really | |
2445 | should know what you are doing to say so. | |
2446 | ||
2447 | if SPECULATION_MITIGATIONS | |
2448 | ||
2449 | config PAGE_TABLE_ISOLATION | |
2450 | bool "Remove the kernel mapping in user mode" | |
2451 | default y | |
2452 | depends on (X86_64 || X86_PAE) | |
2453 | help | |
2454 | This feature reduces the number of hardware side channels by | |
2455 | ensuring that the majority of kernel addresses are not mapped | |
2456 | into userspace. | |
2457 | ||
ff61f079 | 2458 | See Documentation/arch/x86/pti.rst for more details. |
f43b9876 PZ |
2459 | |
2460 | config RETPOLINE | |
2461 | bool "Avoid speculative indirect branches in kernel" | |
2462 | select OBJTOOL if HAVE_OBJTOOL | |
2463 | default y | |
2464 | help | |
2465 | Compile kernel with the retpoline compiler options to guard against | |
2466 | kernel-to-user data leaks by avoiding speculative indirect | |
2467 | branches. Requires a compiler with -mindirect-branch=thunk-extern | |
2468 | support for full protection. The kernel may run slower. | |
2469 | ||
2470 | config RETHUNK | |
2471 | bool "Enable return-thunks" | |
2472 | depends on RETPOLINE && CC_HAS_RETURN_THUNK | |
2473 | select OBJTOOL if HAVE_OBJTOOL | |
b648ab48 | 2474 | default y if X86_64 |
f43b9876 PZ |
2475 | help |
2476 | Compile the kernel with the return-thunks compiler option to guard | |
2477 | against kernel-to-user data leaks by avoiding return speculation. | |
2478 | Requires a compiler with -mfunction-return=thunk-extern | |
2479 | support for full protection. The kernel may run slower. | |
2480 | ||
2481 | config CPU_UNRET_ENTRY | |
2482 | bool "Enable UNRET on kernel entry" | |
b648ab48 | 2483 | depends on CPU_SUP_AMD && RETHUNK && X86_64 |
f43b9876 PZ |
2484 | default y |
2485 | help | |
2486 | Compile the kernel with support for the retbleed=unret mitigation. | |
2487 | ||
80e4c1cd TG |
2488 | config CALL_DEPTH_TRACKING |
2489 | bool "Mitigate RSB underflow with call depth tracking" | |
2490 | depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS | |
2491 | select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE | |
2492 | select CALL_THUNKS | |
2493 | default y | |
2494 | help | |
2495 | Compile the kernel with call depth tracking to mitigate the Intel | |
2496 | SKL Return-Speculation-Buffer (RSB) underflow issue. The | |
2497 | mitigation is off by default and needs to be enabled on the | |
2498 | kernel command line via the retbleed=stuff option. For | |
2499 | non-affected systems the overhead of this option is marginal as | |
2500 | the call depth tracking is using run-time generated call thunks | |
2501 | in a compiler generated padding area and call patching. This | |
2502 | increases text size by ~5%. For non affected systems this space | |
2503 | is unused. On affected SKL systems this results in a significant | |
2504 | performance gain over the IBRS mitigation. | |
2505 | ||
e81dc127 TG |
2506 | config CALL_THUNKS_DEBUG |
2507 | bool "Enable call thunks and call depth tracking debugging" | |
2508 | depends on CALL_DEPTH_TRACKING | |
2509 | select FUNCTION_ALIGNMENT_32B | |
2510 | default n | |
2511 | help | |
2512 | Enable call/ret counters for imbalance detection and build in | |
2513 | a noisy dmesg about callthunks generation and call patching for | |
2514 | trouble shooting. The debug prints need to be enabled on the | |
2515 | kernel command line with 'debug-callthunks'. | |
54628de6 RD |
2516 | Only enable this when you are debugging call thunks as this |
2517 | creates a noticeable runtime overhead. If unsure say N. | |
80e4c1cd | 2518 | |
f43b9876 PZ |
2519 | config CPU_IBPB_ENTRY |
2520 | bool "Enable IBPB on kernel entry" | |
b648ab48 | 2521 | depends on CPU_SUP_AMD && X86_64 |
f43b9876 PZ |
2522 | default y |
2523 | help | |
2524 | Compile the kernel with support for the retbleed=ibpb mitigation. | |
2525 | ||
2526 | config CPU_IBRS_ENTRY | |
2527 | bool "Enable IBRS on kernel entry" | |
b648ab48 | 2528 | depends on CPU_SUP_INTEL && X86_64 |
f43b9876 PZ |
2529 | default y |
2530 | help | |
2531 | Compile the kernel with support for the spectre_v2=ibrs mitigation. | |
2532 | This mitigates both spectre_v2 and retbleed at great cost to | |
2533 | performance. | |
2534 | ||
fb3bd914 BPA |
2535 | config CPU_SRSO |
2536 | bool "Mitigate speculative RAS overflow on AMD" | |
2537 | depends on CPU_SUP_AMD && X86_64 && RETHUNK | |
2538 | default y | |
2539 | help | |
2540 | Enable the SRSO mitigation needed on AMD Zen1-4 machines. | |
2541 | ||
f43b9876 PZ |
2542 | config SLS |
2543 | bool "Mitigate Straight-Line-Speculation" | |
2544 | depends on CC_HAS_SLS && X86_64 | |
2545 | select OBJTOOL if HAVE_OBJTOOL | |
2546 | default n | |
2547 | help | |
2548 | Compile the kernel with straight-line-speculation options to guard | |
2549 | against straight line speculation. The kernel image might be slightly | |
2550 | larger. | |
2551 | ||
53cf5797 DS |
2552 | config GDS_FORCE_MITIGATION |
2553 | bool "Force GDS Mitigation" | |
2554 | depends on CPU_SUP_INTEL | |
2555 | default n | |
2556 | help | |
2557 | Gather Data Sampling (GDS) is a hardware vulnerability which allows | |
2558 | unprivileged speculative access to data which was previously stored in | |
2559 | vector registers. | |
2560 | ||
2561 | This option is equivalent to setting gather_data_sampling=force on the | |
2562 | command line. The microcode mitigation is used if present, otherwise | |
2563 | AVX is disabled as a mitigation. On affected systems that are missing | |
2564 | the microcode any userspace code that unconditionally uses AVX will | |
2565 | break with this option set. | |
2566 | ||
2567 | Setting this option on systems not vulnerable to GDS has no effect. | |
2568 | ||
2569 | If in doubt, say N. | |
2570 | ||
f43b9876 PZ |
2571 | endif |
2572 | ||
3072e413 MH |
2573 | config ARCH_HAS_ADD_PAGES |
2574 | def_bool y | |
5c11f00b | 2575 | depends on ARCH_ENABLE_MEMORY_HOTPLUG |
3072e413 | 2576 | |
da85f865 | 2577 | menu "Power management and ACPI options" |
e279b6c1 SR |
2578 | |
2579 | config ARCH_HIBERNATION_HEADER | |
3c2362e6 | 2580 | def_bool y |
44556530 | 2581 | depends on HIBERNATION |
e279b6c1 SR |
2582 | |
2583 | source "kernel/power/Kconfig" | |
2584 | ||
2585 | source "drivers/acpi/Kconfig" | |
2586 | ||
a6b68076 | 2587 | config X86_APM_BOOT |
6fc108a0 | 2588 | def_bool y |
282e5aab | 2589 | depends on APM |
a6b68076 | 2590 | |
e279b6c1 SR |
2591 | menuconfig APM |
2592 | tristate "APM (Advanced Power Management) BIOS support" | |
efefa6f6 | 2593 | depends on X86_32 && PM_SLEEP |
a7f7f624 | 2594 | help |
e279b6c1 SR |
2595 | APM is a BIOS specification for saving power using several different |
2596 | techniques. This is mostly useful for battery powered laptops with | |
2597 | APM compliant BIOSes. If you say Y here, the system time will be | |
2598 | reset after a RESUME operation, the /proc/apm device will provide | |
2599 | battery status information, and user-space programs will receive | |
2600 | notification of APM "events" (e.g. battery status change). | |
2601 | ||
2602 | If you select "Y" here, you can disable actual use of the APM | |
2603 | BIOS by passing the "apm=off" option to the kernel at boot time. | |
2604 | ||
2605 | Note that the APM support is almost completely disabled for | |
2606 | machines with more than one CPU. | |
2607 | ||
2608 | In order to use APM, you will need supporting software. For location | |
151f4e2b | 2609 | and more information, read <file:Documentation/power/apm-acpi.rst> |
2dc98fd3 | 2610 | and the Battery Powered Linux mini-HOWTO, available from |
e279b6c1 SR |
2611 | <http://www.tldp.org/docs.html#howto>. |
2612 | ||
2613 | This driver does not spin down disk drives (see the hdparm(8) | |
2614 | manpage ("man 8 hdparm") for that), and it doesn't turn off | |
2615 | VESA-compliant "green" monitors. | |
2616 | ||
2617 | This driver does not support the TI 4000M TravelMate and the ACER | |
2618 | 486/DX4/75 because they don't have compliant BIOSes. Many "green" | |
2619 | desktop machines also don't have compliant BIOSes, and this driver | |
2620 | may cause those machines to panic during the boot phase. | |
2621 | ||
2622 | Generally, if you don't have a battery in your machine, there isn't | |
2623 | much point in using this driver and you should say N. If you get | |
2624 | random kernel OOPSes or reboots that don't seem to be related to | |
2625 | anything, try disabling/enabling this option (or disabling/enabling | |
2626 | APM in your BIOS). | |
2627 | ||
2628 | Some other things you should try when experiencing seemingly random, | |
2629 | "weird" problems: | |
2630 | ||
2631 | 1) make sure that you have enough swap space and that it is | |
2632 | enabled. | |
7987448f | 2633 | 2) pass the "idle=poll" option to the kernel |
e279b6c1 SR |
2634 | 3) switch on floating point emulation in the kernel and pass |
2635 | the "no387" option to the kernel | |
2636 | 4) pass the "floppy=nodma" option to the kernel | |
2637 | 5) pass the "mem=4M" option to the kernel (thereby disabling | |
2638 | all but the first 4 MB of RAM) | |
2639 | 6) make sure that the CPU is not over clocked. | |
2640 | 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> | |
2641 | 8) disable the cache from your BIOS settings | |
2642 | 9) install a fan for the video card or exchange video RAM | |
2643 | 10) install a better fan for the CPU | |
2644 | 11) exchange RAM chips | |
2645 | 12) exchange the motherboard. | |
2646 | ||
2647 | To compile this driver as a module, choose M here: the | |
2648 | module will be called apm. | |
2649 | ||
2650 | if APM | |
2651 | ||
2652 | config APM_IGNORE_USER_SUSPEND | |
2653 | bool "Ignore USER SUSPEND" | |
a7f7f624 | 2654 | help |
e279b6c1 SR |
2655 | This option will ignore USER SUSPEND requests. On machines with a |
2656 | compliant APM BIOS, you want to say N. However, on the NEC Versa M | |
2657 | series notebooks, it is necessary to say Y because of a BIOS bug. | |
2658 | ||
2659 | config APM_DO_ENABLE | |
2660 | bool "Enable PM at boot time" | |
a7f7f624 | 2661 | help |
e279b6c1 SR |
2662 | Enable APM features at boot time. From page 36 of the APM BIOS |
2663 | specification: "When disabled, the APM BIOS does not automatically | |
2664 | power manage devices, enter the Standby State, enter the Suspend | |
2665 | State, or take power saving steps in response to CPU Idle calls." | |
2666 | This driver will make CPU Idle calls when Linux is idle (unless this | |
2667 | feature is turned off -- see "Do CPU IDLE calls", below). This | |
2668 | should always save battery power, but more complicated APM features | |
2669 | will be dependent on your BIOS implementation. You may need to turn | |
2670 | this option off if your computer hangs at boot time when using APM | |
2671 | support, or if it beeps continuously instead of suspending. Turn | |
2672 | this off if you have a NEC UltraLite Versa 33/C or a Toshiba | |
2673 | T400CDT. This is off by default since most machines do fine without | |
2674 | this feature. | |
2675 | ||
2676 | config APM_CPU_IDLE | |
dd8af076 | 2677 | depends on CPU_IDLE |
e279b6c1 | 2678 | bool "Make CPU Idle calls when idle" |
a7f7f624 | 2679 | help |
e279b6c1 SR |
2680 | Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. |
2681 | On some machines, this can activate improved power savings, such as | |
2682 | a slowed CPU clock rate, when the machine is idle. These idle calls | |
2683 | are made after the idle loop has run for some length of time (e.g., | |
2684 | 333 mS). On some machines, this will cause a hang at boot time or | |
2685 | whenever the CPU becomes idle. (On machines with more than one CPU, | |
2686 | this option does nothing.) | |
2687 | ||
2688 | config APM_DISPLAY_BLANK | |
2689 | bool "Enable console blanking using APM" | |
a7f7f624 | 2690 | help |
e279b6c1 SR |
2691 | Enable console blanking using the APM. Some laptops can use this to |
2692 | turn off the LCD backlight when the screen blanker of the Linux | |
2693 | virtual console blanks the screen. Note that this is only used by | |
2694 | the virtual console screen blanker, and won't turn off the backlight | |
2695 | when using the X Window system. This also doesn't have anything to | |
2696 | do with your VESA-compliant power-saving monitor. Further, this | |
2697 | option doesn't work for all laptops -- it might not turn off your | |
2698 | backlight at all, or it might print a lot of errors to the console, | |
2699 | especially if you are using gpm. | |
2700 | ||
2701 | config APM_ALLOW_INTS | |
2702 | bool "Allow interrupts during APM BIOS calls" | |
a7f7f624 | 2703 | help |
e279b6c1 SR |
2704 | Normally we disable external interrupts while we are making calls to |
2705 | the APM BIOS as a measure to lessen the effects of a badly behaving | |
2706 | BIOS implementation. The BIOS should reenable interrupts if it | |
2707 | needs to. Unfortunately, some BIOSes do not -- especially those in | |
2708 | many of the newer IBM Thinkpads. If you experience hangs when you | |
2709 | suspend, try setting this to Y. Otherwise, say N. | |
2710 | ||
e279b6c1 SR |
2711 | endif # APM |
2712 | ||
bb0a56ec | 2713 | source "drivers/cpufreq/Kconfig" |
e279b6c1 SR |
2714 | |
2715 | source "drivers/cpuidle/Kconfig" | |
2716 | ||
27471fdb AH |
2717 | source "drivers/idle/Kconfig" |
2718 | ||
e279b6c1 SR |
2719 | endmenu |
2720 | ||
e279b6c1 SR |
2721 | menu "Bus options (PCI etc.)" |
2722 | ||
e279b6c1 SR |
2723 | choice |
2724 | prompt "PCI access mode" | |
efefa6f6 | 2725 | depends on X86_32 && PCI |
e279b6c1 | 2726 | default PCI_GOANY |
a7f7f624 | 2727 | help |
e279b6c1 SR |
2728 | On PCI systems, the BIOS can be used to detect the PCI devices and |
2729 | determine their configuration. However, some old PCI motherboards | |
2730 | have BIOS bugs and may crash if this is done. Also, some embedded | |
2731 | PCI-based systems don't have any BIOS at all. Linux can also try to | |
2732 | detect the PCI hardware directly without using the BIOS. | |
2733 | ||
2734 | With this option, you can specify how Linux should detect the | |
2735 | PCI devices. If you choose "BIOS", the BIOS will be used, | |
2736 | if you choose "Direct", the BIOS won't be used, and if you | |
2737 | choose "MMConfig", then PCI Express MMCONFIG will be used. | |
2738 | If you choose "Any", the kernel will try MMCONFIG, then the | |
2739 | direct access method and falls back to the BIOS if that doesn't | |
2740 | work. If unsure, go with the default, which is "Any". | |
2741 | ||
2742 | config PCI_GOBIOS | |
2743 | bool "BIOS" | |
2744 | ||
2745 | config PCI_GOMMCONFIG | |
2746 | bool "MMConfig" | |
2747 | ||
2748 | config PCI_GODIRECT | |
2749 | bool "Direct" | |
2750 | ||
3ef0e1f8 | 2751 | config PCI_GOOLPC |
76fb6570 | 2752 | bool "OLPC XO-1" |
3ef0e1f8 AS |
2753 | depends on OLPC |
2754 | ||
2bdd1b03 AS |
2755 | config PCI_GOANY |
2756 | bool "Any" | |
2757 | ||
e279b6c1 SR |
2758 | endchoice |
2759 | ||
2760 | config PCI_BIOS | |
3c2362e6 | 2761 | def_bool y |
efefa6f6 | 2762 | depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) |
e279b6c1 SR |
2763 | |
2764 | # x86-64 doesn't support PCI BIOS access from long mode so always go direct. | |
2765 | config PCI_DIRECT | |
3c2362e6 | 2766 | def_bool y |
0aba496f | 2767 | depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) |
e279b6c1 SR |
2768 | |
2769 | config PCI_MMCONFIG | |
b45c9f36 JK |
2770 | bool "Support mmconfig PCI config space access" if X86_64 |
2771 | default y | |
4590d98f | 2772 | depends on PCI && (ACPI || JAILHOUSE_GUEST) |
b45c9f36 | 2773 | depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) |
e279b6c1 | 2774 | |
3ef0e1f8 | 2775 | config PCI_OLPC |
2bdd1b03 AS |
2776 | def_bool y |
2777 | depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) | |
3ef0e1f8 | 2778 | |
b5401a96 AN |
2779 | config PCI_XEN |
2780 | def_bool y | |
2781 | depends on PCI && XEN | |
b5401a96 | 2782 | |
8364e1f8 JK |
2783 | config MMCONF_FAM10H |
2784 | def_bool y | |
2785 | depends on X86_64 && PCI_MMCONFIG && ACPI | |
e279b6c1 | 2786 | |
3f6ea84a | 2787 | config PCI_CNB20LE_QUIRK |
6a108a14 | 2788 | bool "Read CNB20LE Host Bridge Windows" if EXPERT |
6ea30386 | 2789 | depends on PCI |
3f6ea84a IS |
2790 | help |
2791 | Read the PCI windows out of the CNB20LE host bridge. This allows | |
2792 | PCI hotplug to work on systems with the CNB20LE chipset which do | |
2793 | not have ACPI. | |
2794 | ||
64a5fed6 BH |
2795 | There's no public spec for this chipset, and this functionality |
2796 | is known to be incomplete. | |
2797 | ||
2798 | You should say N unless you know you need this. | |
2799 | ||
3a495511 | 2800 | config ISA_BUS |
17a2a129 | 2801 | bool "ISA bus support on modern systems" if EXPERT |
3a495511 | 2802 | help |
17a2a129 WBG |
2803 | Expose ISA bus device drivers and options available for selection and |
2804 | configuration. Enable this option if your target machine has an ISA | |
2805 | bus. ISA is an older system, displaced by PCI and newer bus | |
2806 | architectures -- if your target machine is modern, it probably does | |
2807 | not have an ISA bus. | |
3a495511 WBG |
2808 | |
2809 | If unsure, say N. | |
2810 | ||
1c00f016 | 2811 | # x86_64 have no ISA slots, but can have ISA-style DMA. |
e279b6c1 | 2812 | config ISA_DMA_API |
1c00f016 DR |
2813 | bool "ISA-style DMA support" if (X86_64 && EXPERT) |
2814 | default y | |
2815 | help | |
2816 | Enables ISA-style DMA support for devices requiring such controllers. | |
2817 | If unsure, say Y. | |
e279b6c1 | 2818 | |
51e68d05 LT |
2819 | if X86_32 |
2820 | ||
e279b6c1 SR |
2821 | config ISA |
2822 | bool "ISA support" | |
a7f7f624 | 2823 | help |
e279b6c1 SR |
2824 | Find out whether you have ISA slots on your motherboard. ISA is the |
2825 | name of a bus system, i.e. the way the CPU talks to the other stuff | |
2826 | inside your box. Other bus systems are PCI, EISA, MicroChannel | |
2827 | (MCA) or VESA. ISA is an older system, now being displaced by PCI; | |
2828 | newer boards don't support it. If you have ISA, say Y, otherwise N. | |
2829 | ||
e279b6c1 SR |
2830 | config SCx200 |
2831 | tristate "NatSemi SCx200 support" | |
a7f7f624 | 2832 | help |
e279b6c1 SR |
2833 | This provides basic support for National Semiconductor's |
2834 | (now AMD's) Geode processors. The driver probes for the | |
2835 | PCI-IDs of several on-chip devices, so its a good dependency | |
2836 | for other scx200_* drivers. | |
2837 | ||
2838 | If compiled as a module, the driver is named scx200. | |
2839 | ||
2840 | config SCx200HR_TIMER | |
2841 | tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" | |
592913ec | 2842 | depends on SCx200 |
e279b6c1 | 2843 | default y |
a7f7f624 | 2844 | help |
e279b6c1 SR |
2845 | This driver provides a clocksource built upon the on-chip |
2846 | 27MHz high-resolution timer. Its also a workaround for | |
2847 | NSC Geode SC-1100's buggy TSC, which loses time when the | |
2848 | processor goes idle (as is done by the scheduler). The | |
2849 | other workaround is idle=poll boot option. | |
2850 | ||
3ef0e1f8 AS |
2851 | config OLPC |
2852 | bool "One Laptop Per Child support" | |
54008979 | 2853 | depends on !X86_PAE |
3c554946 | 2854 | select GPIOLIB |
dc3119e7 | 2855 | select OF |
45bb1674 | 2856 | select OF_PROMTREE |
b4e51854 | 2857 | select IRQ_DOMAIN |
0c3d931b | 2858 | select OLPC_EC |
a7f7f624 | 2859 | help |
3ef0e1f8 AS |
2860 | Add support for detecting the unique features of the OLPC |
2861 | XO hardware. | |
2862 | ||
a3128588 DD |
2863 | config OLPC_XO1_PM |
2864 | bool "OLPC XO-1 Power Management" | |
fa112cf1 | 2865 | depends on OLPC && MFD_CS5535=y && PM_SLEEP |
a7f7f624 | 2866 | help |
97c4cb71 | 2867 | Add support for poweroff and suspend of the OLPC XO-1 laptop. |
bf1ebf00 | 2868 | |
cfee9597 DD |
2869 | config OLPC_XO1_RTC |
2870 | bool "OLPC XO-1 Real Time Clock" | |
2871 | depends on OLPC_XO1_PM && RTC_DRV_CMOS | |
a7f7f624 | 2872 | help |
cfee9597 DD |
2873 | Add support for the XO-1 real time clock, which can be used as a |
2874 | programmable wakeup source. | |
2875 | ||
7feda8e9 DD |
2876 | config OLPC_XO1_SCI |
2877 | bool "OLPC XO-1 SCI extras" | |
92e830f2 | 2878 | depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y |
ed8e47fe | 2879 | depends on INPUT=y |
d8d01a63 | 2880 | select POWER_SUPPLY |
a7f7f624 | 2881 | help |
7feda8e9 | 2882 | Add support for SCI-based features of the OLPC XO-1 laptop: |
7bc74b3d | 2883 | - EC-driven system wakeups |
7feda8e9 | 2884 | - Power button |
7bc74b3d | 2885 | - Ebook switch |
2cf2baea | 2886 | - Lid switch |
e1040ac6 DD |
2887 | - AC adapter status updates |
2888 | - Battery status updates | |
7feda8e9 | 2889 | |
a0f30f59 DD |
2890 | config OLPC_XO15_SCI |
2891 | bool "OLPC XO-1.5 SCI extras" | |
d8d01a63 DD |
2892 | depends on OLPC && ACPI |
2893 | select POWER_SUPPLY | |
a7f7f624 | 2894 | help |
a0f30f59 DD |
2895 | Add support for SCI-based features of the OLPC XO-1.5 laptop: |
2896 | - EC-driven system wakeups | |
2897 | - AC adapter status updates | |
2898 | - Battery status updates | |
bf1ebf00 | 2899 | |
d4f3e350 EW |
2900 | config ALIX |
2901 | bool "PCEngines ALIX System Support (LED setup)" | |
2902 | select GPIOLIB | |
a7f7f624 | 2903 | help |
d4f3e350 EW |
2904 | This option enables system support for the PCEngines ALIX. |
2905 | At present this just sets up LEDs for GPIO control on | |
2906 | ALIX2/3/6 boards. However, other system specific setup should | |
2907 | get added here. | |
2908 | ||
2909 | Note: You must still enable the drivers for GPIO and LED support | |
2910 | (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs | |
2911 | ||
2912 | Note: You have to set alix.force=1 for boards with Award BIOS. | |
2913 | ||
da4e3302 PP |
2914 | config NET5501 |
2915 | bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" | |
2916 | select GPIOLIB | |
a7f7f624 | 2917 | help |
da4e3302 PP |
2918 | This option enables system support for the Soekris Engineering net5501. |
2919 | ||
3197059a PP |
2920 | config GEOS |
2921 | bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" | |
2922 | select GPIOLIB | |
2923 | depends on DMI | |
a7f7f624 | 2924 | help |
3197059a PP |
2925 | This option enables system support for the Traverse Technologies GEOS. |
2926 | ||
7d029125 VD |
2927 | config TS5500 |
2928 | bool "Technologic Systems TS-5500 platform support" | |
2929 | depends on MELAN | |
2930 | select CHECK_SIGNATURE | |
2931 | select NEW_LEDS | |
2932 | select LEDS_CLASS | |
a7f7f624 | 2933 | help |
7d029125 VD |
2934 | This option enables system support for the Technologic Systems TS-5500. |
2935 | ||
bc0120fd SR |
2936 | endif # X86_32 |
2937 | ||
23ac4ae8 | 2938 | config AMD_NB |
e279b6c1 | 2939 | def_bool y |
0e152cd7 | 2940 | depends on CPU_SUP_AMD && PCI |
e279b6c1 | 2941 | |
e279b6c1 SR |
2942 | endmenu |
2943 | ||
1572497c | 2944 | menu "Binary Emulations" |
e279b6c1 SR |
2945 | |
2946 | config IA32_EMULATION | |
2947 | bool "IA32 Emulation" | |
2948 | depends on X86_64 | |
39f88911 | 2949 | select ARCH_WANT_OLD_COMPAT_IPC |
d1603990 | 2950 | select BINFMT_ELF |
39f88911 | 2951 | select COMPAT_OLD_SIGACTION |
a7f7f624 | 2952 | help |
5fd92e65 L |
2953 | Include code to run legacy 32-bit programs under a |
2954 | 64-bit kernel. You should likely turn this on, unless you're | |
2955 | 100% sure that you don't have any 32-bit programs left. | |
e279b6c1 | 2956 | |
83a44a4f | 2957 | config X86_X32_ABI |
6ea30386 | 2958 | bool "x32 ABI for 64-bit mode" |
9b54050b | 2959 | depends on X86_64 |
aaeed6ec NC |
2960 | # llvm-objcopy does not convert x86_64 .note.gnu.property or |
2961 | # compressed debug sections to x86_x32 properly: | |
2962 | # https://github.com/ClangBuiltLinux/linux/issues/514 | |
2963 | # https://github.com/ClangBuiltLinux/linux/issues/1141 | |
2964 | depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) | |
a7f7f624 | 2965 | help |
5fd92e65 L |
2966 | Include code to run binaries for the x32 native 32-bit ABI |
2967 | for 64-bit processors. An x32 process gets access to the | |
2968 | full 64-bit register file and wide data path while leaving | |
2969 | pointers at 32 bits for smaller memory footprint. | |
2970 | ||
953fee1d IM |
2971 | config COMPAT_32 |
2972 | def_bool y | |
2973 | depends on IA32_EMULATION || X86_32 | |
2974 | select HAVE_UID16 | |
2975 | select OLD_SIGSUSPEND3 | |
2976 | ||
e279b6c1 | 2977 | config COMPAT |
3c2362e6 | 2978 | def_bool y |
83a44a4f | 2979 | depends on IA32_EMULATION || X86_X32_ABI |
e279b6c1 SR |
2980 | |
2981 | config COMPAT_FOR_U64_ALIGNMENT | |
3120e25e | 2982 | def_bool y |
a9251280 | 2983 | depends on COMPAT |
ee009e4a | 2984 | |
e279b6c1 SR |
2985 | endmenu |
2986 | ||
e5beae16 KP |
2987 | config HAVE_ATOMIC_IOMAP |
2988 | def_bool y | |
2989 | depends on X86_32 | |
2990 | ||
edf88417 | 2991 | source "arch/x86/kvm/Kconfig" |
5e8ebd84 JD |
2992 | |
2993 | source "arch/x86/Kconfig.assembler" |