Commit | Line | Data |
---|---|---|
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 |
f9aad622 | 29 | select ARCH_HAS_PTDUMP |
3049def1 | 30 | select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS |
c12d3362 | 31 | select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 |
0bff0aae | 32 | select ARCH_SUPPORTS_PER_VMA_LOCK |
75182022 | 33 | select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE |
d94e0685 IM |
34 | select HAVE_ARCH_SOFT_DIRTY |
35 | select MODULES_USE_ELF_RELA | |
f616ab59 | 36 | select NEED_DMA_MAP_STATE |
09230cbc | 37 | select SWIOTLB |
7facdc42 | 38 | select ARCH_HAS_ELFCORE_COMPAT |
63703f37 | 39 | select ZONE_DMA32 |
14e56fb2 | 40 | select EXECMEM if DYNAMIC_FTRACE |
b9020bdb | 41 | select ACPI_MRRM if ACPI |
1032c0ba | 42 | |
518049d9 SRV |
43 | config FORCE_DYNAMIC_FTRACE |
44 | def_bool y | |
45 | depends on X86_32 | |
46 | depends on FUNCTION_TRACER | |
47 | select DYNAMIC_FTRACE | |
48 | help | |
758cd94a JH |
49 | We keep the static function tracing (!DYNAMIC_FTRACE) around |
50 | in order to test the non static function tracing in the | |
51 | generic code, as other architectures still use it. But we | |
52 | only need to keep it around for x86_64. No need to keep it | |
53 | for x86_32. For x86_32, force DYNAMIC_FTRACE. | |
d94e0685 IM |
54 | # |
55 | # Arch settings | |
56 | # | |
57 | # ( Note that options that are marked 'if X86_64' could in principle be | |
58 | # ported to 32-bit as well. ) | |
59 | # | |
8d5fffb9 | 60 | config X86 |
3c2362e6 | 61 | def_bool y |
c763ea26 IM |
62 | # |
63 | # Note: keep this list sorted alphabetically | |
64 | # | |
6471b825 IM |
65 | select ACPI_LEGACY_TABLES_LOOKUP if ACPI |
66 | select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI | |
a02f66bb | 67 | select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU |
942fa985 | 68 | select ARCH_32BIT_OFF_T if X86_32 |
2a21ad57 | 69 | select ARCH_CLOCKSOURCE_INIT |
fe42754b | 70 | select ARCH_CONFIGURES_CPU_MITIGATIONS |
1f6d3a8f | 71 | select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE |
1e866974 | 72 | select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION |
5c11f00b | 73 | select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 |
91024b3c | 74 | select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG |
cebc774f | 75 | select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) |
1e866974 | 76 | select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE |
c763ea26 | 77 | select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI |
c2280be8 | 78 | select ARCH_HAS_CACHE_LINE_SIZE |
1156b441 | 79 | select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION |
7c7077a7 | 80 | select ARCH_HAS_CPU_FINALIZE_INIT |
8f23f5db | 81 | select ARCH_HAS_CPU_PASID if IOMMU_SVA |
55d1ecce | 82 | select ARCH_HAS_CRC32 |
4ffd5086 | 83 | select ARCH_HAS_CRC64 if X86_64 |
dbdda1fd | 84 | select ARCH_HAS_CRC_T10DIF |
2792d84e | 85 | select ARCH_HAS_CURRENT_STACK_POINTER |
fa5b6ec9 | 86 | select ARCH_HAS_DEBUG_VIRTUAL |
399145f9 | 87 | select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE |
21266be9 | 88 | select ARCH_HAS_DEVMEM_IS_ALLOWED |
de6c85bf | 89 | select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN |
b1a57bbf | 90 | select ARCH_HAS_EARLY_DEBUG if KGDB |
6471b825 | 91 | select ARCH_HAS_ELF_RANDOMIZE |
47410d83 | 92 | select ARCH_HAS_EXECMEM_ROX if X86_64 && STRICT_MODULE_RWX |
72d93104 | 93 | select ARCH_HAS_FAST_MULTIPLIER |
6974f0c4 | 94 | select ARCH_HAS_FORTIFY_SOURCE |
957e3fac | 95 | select ARCH_HAS_GCOV_PROFILE_ALL |
bece04b5 | 96 | select ARCH_HAS_KCOV if X86_64 |
b0b8a15b | 97 | select ARCH_HAS_KERNEL_FPU_SUPPORT |
0c9c1d56 | 98 | select ARCH_HAS_MEM_ENCRYPT |
10bcc80e | 99 | select ARCH_HAS_MEMBARRIER_SYNC_CORE |
49f88c70 | 100 | select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS |
0ebeea8c | 101 | select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
c763ea26 | 102 | select ARCH_HAS_PMEM_API if X86_64 |
476e8583 | 103 | select ARCH_HAS_PREEMPT_LAZY |
17596731 | 104 | select ARCH_HAS_PTE_DEVMAP if X86_64 |
3010a5ea | 105 | select ARCH_HAS_PTE_SPECIAL |
71ce1ab5 | 106 | select ARCH_HAS_HW_PTE_YOUNG |
eed9a328 | 107 | select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2 |
0aed55af | 108 | select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 |
ec6347bb | 109 | select ARCH_HAS_COPY_MC if X86_64 |
d2852a22 | 110 | select ARCH_HAS_SET_MEMORY |
d253ca0c | 111 | select ARCH_HAS_SET_DIRECT_MAP |
ad21fc4f LA |
112 | select ARCH_HAS_STRICT_KERNEL_RWX |
113 | select ARCH_HAS_STRICT_MODULE_RWX | |
ac1ab12a | 114 | select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE |
25c619e5 | 115 | select ARCH_HAS_SYSCALL_WRAPPER |
918327e9 | 116 | select ARCH_HAS_UBSAN |
7e01ccb4 | 117 | select ARCH_HAS_DEBUG_WX |
63703f37 | 118 | select ARCH_HAS_ZONE_DMA_SET if EXPERT |
6471b825 | 119 | select ARCH_HAVE_NMI_SAFE_CMPXCHG |
ba386777 | 120 | select ARCH_HAVE_EXTRA_ELF_NOTES |
04d5ea46 | 121 | select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE |
6471b825 | 122 | select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI |
77fbbc81 | 123 | select ARCH_MIGHT_HAVE_PC_PARPORT |
5e2c18c0 | 124 | select ARCH_MIGHT_HAVE_PC_SERIO |
3599fe12 | 125 | select ARCH_STACKWALK |
2c870e61 | 126 | select ARCH_SUPPORTS_ACPI |
6471b825 | 127 | select ARCH_SUPPORTS_ATOMIC_RMW |
5d6ad668 | 128 | select ARCH_SUPPORTS_DEBUG_PAGEALLOC |
d283d422 | 129 | select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 |
6471b825 | 130 | select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 |
14df3267 | 131 | select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 |
3c516f89 ST |
132 | select ARCH_SUPPORTS_CFI_CLANG if X86_64 |
133 | select ARCH_USES_CFI_TRAPS if X86_64 && CFI_CLANG | |
583bfd48 NC |
134 | select ARCH_SUPPORTS_LTO_CLANG |
135 | select ARCH_SUPPORTS_LTO_CLANG_THIN | |
d2d6422f | 136 | select ARCH_SUPPORTS_RT |
315ad878 | 137 | select ARCH_SUPPORTS_AUTOFDO_CLANG |
d5dc9583 | 138 | select ARCH_SUPPORTS_PROPELLER_CLANG if X86_64 |
6471b825 | 139 | select ARCH_USE_BUILTIN_BSWAP |
909639aa | 140 | select ARCH_USE_CMPXCHG_LOCKREF if X86_CX8 |
dce44566 | 141 | select ARCH_USE_MEMTEST |
6471b825 IM |
142 | select ARCH_USE_QUEUED_RWLOCKS |
143 | select ARCH_USE_QUEUED_SPINLOCKS | |
2ce0d7f9 | 144 | select ARCH_USE_SYM_ANNOTATIONS |
ce4a4e56 | 145 | select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH |
81c22041 | 146 | select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 |
c763ea26 | 147 | select ARCH_WANTS_DYNAMIC_TASK_STRUCT |
51c2ee6d | 148 | select ARCH_WANTS_NO_INSTR |
07431506 | 149 | select ARCH_WANT_GENERAL_HUGETLB |
3876d4a3 | 150 | select ARCH_WANT_HUGE_PMD_SHARE |
59612b24 | 151 | select ARCH_WANT_LD_ORPHAN_WARN |
0b6f1582 AK |
152 | select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64 |
153 | select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64 | |
08efe293 | 154 | select ARCH_WANT_HUGETLB_VMEMMAP_PREINIT if X86_64 |
38d8b4e6 | 155 | select ARCH_WANTS_THP_SWAP if X86_64 |
b5f06f64 | 156 | select ARCH_HAS_PARANOID_L1D_FLUSH |
af896715 | 157 | select ARCH_WANT_IRQS_OFF_ACTIVATE_MM |
10916706 | 158 | select BUILDTIME_TABLE_SORT |
6471b825 | 159 | select CLKEVT_I8253 |
6471b825 | 160 | select CLOCKSOURCE_WATCHDOG |
7cf8f44a AP |
161 | # Word-size accesses may read uninitialized data past the trailing \0 |
162 | # in strings and cause false KMSAN reports. | |
163 | select DCACHE_WORD_ACCESS if !KMSAN | |
3aac3ebe | 164 | select DYNAMIC_SIGFRAME |
45471cd9 LT |
165 | select EDAC_ATOMIC_SCRUB |
166 | select EDAC_SUPPORT | |
6471b825 | 167 | select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) |
cb81deef | 168 | select GENERIC_CLOCKEVENTS_BROADCAST_IDLE if GENERIC_CLOCKEVENTS_BROADCAST |
6471b825 IM |
169 | select GENERIC_CLOCKEVENTS_MIN_ADJUST |
170 | select GENERIC_CMOS_UPDATE | |
171 | select GENERIC_CPU_AUTOPROBE | |
5b95f94c | 172 | select GENERIC_CPU_DEVICES |
61dc0f55 | 173 | select GENERIC_CPU_VULNERABILITIES |
5b7c73e0 | 174 | select GENERIC_EARLY_IOREMAP |
27d6b4d1 | 175 | select GENERIC_ENTRY |
6471b825 | 176 | select GENERIC_IOMAP |
c7d6c9dd | 177 | select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP |
0fa115da | 178 | select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC |
ad7a929f | 179 | select GENERIC_IRQ_MIGRATION if SMP |
6471b825 | 180 | select GENERIC_IRQ_PROBE |
c201c917 | 181 | select GENERIC_IRQ_RESERVATION_MODE |
6471b825 IM |
182 | select GENERIC_IRQ_SHOW |
183 | select GENERIC_PENDING_IRQ if SMP | |
184 | select GENERIC_SMP_IDLE_THREAD | |
6471b825 | 185 | select GENERIC_TIME_VSYSCALL |
7ac87074 | 186 | select GENERIC_GETTIMEOFDAY |
dafde296 | 187 | select GENERIC_VDSO_DATA_STORE |
550a77a7 | 188 | select GENERIC_VDSO_TIME_NS |
7e90ffb7 | 189 | select GENERIC_VDSO_OVERFLOW_PROTECT |
6ca297d4 | 190 | select GUP_GET_PXX_LOW_HIGH if X86_PAE |
17e5888e | 191 | select HARDIRQS_SW_RESEND |
7edaeb68 | 192 | select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 |
fcbfe812 | 193 | select HAS_IOPORT |
6471b825 IM |
194 | select HAVE_ACPI_APEI if ACPI |
195 | select HAVE_ACPI_APEI_NMI if ACPI | |
2a19be61 | 196 | select HAVE_ALIGNED_STRUCT_PAGE |
6471b825 IM |
197 | select HAVE_ARCH_AUDITSYSCALL |
198 | select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE | |
eed1fcee | 199 | select HAVE_ARCH_HUGE_VMALLOC if X86_64 |
6471b825 | 200 | select HAVE_ARCH_JUMP_LABEL |
b34006c4 | 201 | select HAVE_ARCH_JUMP_LABEL_RELATIVE |
d17a1d97 | 202 | select HAVE_ARCH_KASAN if X86_64 |
0609ae01 | 203 | select HAVE_ARCH_KASAN_VMALLOC if X86_64 |
1dc0da6e | 204 | select HAVE_ARCH_KFENCE |
4ca8cc8d | 205 | select HAVE_ARCH_KMSAN if X86_64 |
6471b825 | 206 | select HAVE_ARCH_KGDB |
9e08f57d DC |
207 | select HAVE_ARCH_MMAP_RND_BITS if MMU |
208 | select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT | |
1b028f78 | 209 | select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT |
271ca788 | 210 | select HAVE_ARCH_PREL32_RELOCATIONS |
6471b825 | 211 | select HAVE_ARCH_SECCOMP_FILTER |
f7d83c1c | 212 | select HAVE_ARCH_THREAD_STRUCT_WHITELIST |
afaef01c | 213 | select HAVE_ARCH_STACKLEAK |
6471b825 IM |
214 | select HAVE_ARCH_TRACEHOOK |
215 | select HAVE_ARCH_TRANSPARENT_HUGEPAGE | |
a00cc7d9 | 216 | select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 |
b64d8d1e | 217 | select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD |
7677f7fd | 218 | select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD |
e37e43a4 | 219 | select HAVE_ARCH_VMAP_STACK if X86_64 |
fe950f60 | 220 | select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET |
c763ea26 | 221 | select HAVE_ARCH_WITHIN_STACK_FRAMES |
2ff2b7ec | 222 | select HAVE_ASM_MODVERSIONS |
6471b825 IM |
223 | select HAVE_CMPXCHG_DOUBLE |
224 | select HAVE_CMPXCHG_LOCAL | |
24a9c541 FW |
225 | select HAVE_CONTEXT_TRACKING_USER if X86_64 |
226 | select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER | |
cf4db259 | 227 | select HAVE_C_RECORDMCOUNT |
03f16cd0 | 228 | select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL |
280981d6 | 229 | select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT |
4ed308c4 | 230 | select HAVE_BUILDTIME_MCOUNT_SORT |
6471b825 | 231 | select HAVE_DEBUG_KMEMLEAK |
6471b825 | 232 | select HAVE_DMA_CONTIGUOUS |
677aa9f7 | 233 | select HAVE_DYNAMIC_FTRACE |
06aeaaea | 234 | select HAVE_DYNAMIC_FTRACE_WITH_REGS |
02a474ca | 235 | select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 |
762abbc0 | 236 | select HAVE_FTRACE_REGS_HAVING_PT_REGS if X86_64 |
562955fe | 237 | select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
c316eb44 | 238 | select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 |
503e4510 | 239 | select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 |
03f5781b | 240 | select HAVE_EBPF_JIT |
58340a07 | 241 | select HAVE_EFFICIENT_UNALIGNED_ACCESS |
976ba8da | 242 | select HAVE_EISA if X86_32 |
5f56a5df | 243 | select HAVE_EXIT_THREAD |
25176ad0 | 244 | select HAVE_GUP_FAST |
644e0e8d | 245 | select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE |
a762e926 | 246 | select HAVE_FTRACE_GRAPH_FUNC if HAVE_FUNCTION_GRAPH_TRACER |
6471b825 | 247 | select HAVE_FTRACE_MCOUNT_RECORD |
a3ed4157 | 248 | select HAVE_FUNCTION_GRAPH_FREGS if HAVE_FUNCTION_GRAPH_TRACER |
4a30e4c9 | 249 | select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) |
6471b825 | 250 | select HAVE_FUNCTION_TRACER |
6b90bd4b | 251 | select HAVE_GCC_PLUGINS |
6471b825 | 252 | select HAVE_HW_BREAKPOINT |
6471b825 | 253 | select HAVE_IOREMAP_PROT |
624db9ea | 254 | select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 |
6471b825 | 255 | select HAVE_IRQ_TIME_ACCOUNTING |
4ab7674f | 256 | select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL |
2e9f3bdd | 257 | select HAVE_KERNEL_BZIP2 |
6471b825 IM |
258 | select HAVE_KERNEL_GZIP |
259 | select HAVE_KERNEL_LZ4 | |
2e9f3bdd | 260 | select HAVE_KERNEL_LZMA |
13510997 | 261 | select HAVE_KERNEL_LZO |
6471b825 | 262 | select HAVE_KERNEL_XZ |
fb46d057 | 263 | select HAVE_KERNEL_ZSTD |
6471b825 IM |
264 | select HAVE_KPROBES |
265 | select HAVE_KPROBES_ON_FTRACE | |
540adea3 | 266 | select HAVE_FUNCTION_ERROR_INJECTION |
6471b825 | 267 | select HAVE_KRETPROBES |
f3a112c0 | 268 | select HAVE_RETHOOK |
6471b825 | 269 | select HAVE_LIVEPATCH if X86_64 |
0102752e | 270 | select HAVE_MIXED_BREAKPOINTS_REGS |
ee9f8fce | 271 | select HAVE_MOD_ARCH_SPECIFIC |
9f132f7e | 272 | select HAVE_MOVE_PMD |
be37c98d | 273 | select HAVE_MOVE_PUD |
22102f45 | 274 | select HAVE_NOINSTR_HACK if HAVE_OBJTOOL |
42a0bb3f | 275 | select HAVE_NMI |
489e355b | 276 | select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL |
03f16cd0 | 277 | select HAVE_OBJTOOL if X86_64 |
6471b825 | 278 | select HAVE_OPTPROBES |
5394f1e9 | 279 | select HAVE_PAGE_SIZE_4KB |
6471b825 IM |
280 | select HAVE_PCSPKR_PLATFORM |
281 | select HAVE_PERF_EVENTS | |
c01d4323 | 282 | select HAVE_PERF_EVENTS_NMI |
92e5aae4 | 283 | select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI |
eb01d42a | 284 | select HAVE_PCI |
c5e63197 | 285 | select HAVE_PERF_REGS |
c5ebcedb | 286 | select HAVE_PERF_USER_STACK_DUMP |
a3725973 | 287 | select MMU_GATHER_RCU_TABLE_FREE |
1e9fdf21 | 288 | select MMU_GATHER_MERGE_VMAS |
00998085 | 289 | select HAVE_POSIX_CPU_TIMERS_TASK_WORK |
6471b825 | 290 | select HAVE_REGS_AND_STACK_ACCESS_API |
03f16cd0 | 291 | select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION |
3c88ee19 | 292 | select HAVE_FUNCTION_ARG_ACCESS_API |
7ecd19cf | 293 | select HAVE_SETUP_PER_CPU_AREA |
cd1a41ce | 294 | select HAVE_SOFTIRQ_ON_OWN_STACK |
0ee2689b | 295 | select HAVE_STACKPROTECTOR |
03f16cd0 | 296 | select HAVE_STACK_VALIDATION if HAVE_OBJTOOL |
e6d6c071 | 297 | select HAVE_STATIC_CALL |
03f16cd0 | 298 | select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL |
99cf983c | 299 | select HAVE_PREEMPT_DYNAMIC_CALL |
d6761b8f | 300 | select HAVE_RSEQ |
09498135 | 301 | select HAVE_RUST if X86_64 |
6471b825 | 302 | select HAVE_SYSCALL_TRACEPOINTS |
5f3da8c0 | 303 | select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL |
6471b825 | 304 | select HAVE_UNSTABLE_SCHED_CLOCK |
7c68af6e | 305 | select HAVE_USER_RETURN_NOTIFIER |
7ac87074 | 306 | select HAVE_GENERIC_VDSO |
33385150 | 307 | select VDSO_GETRANDOM if X86_64 |
0c7ffa32 | 308 | select HOTPLUG_PARALLEL if SMP && X86_64 |
05736e4a | 309 | select HOTPLUG_SMT if SMP |
0c7ffa32 | 310 | select HOTPLUG_SPLIT_STARTUP if SMP && X86_32 |
c0185808 | 311 | select IRQ_FORCED_THREADING |
c2508ec5 | 312 | select LOCK_MM_AND_FIND_VMA |
7ecd19cf KW |
313 | select NEED_PER_CPU_EMBED_FIRST_CHUNK |
314 | select NEED_PER_CPU_PAGE_FIRST_CHUNK | |
86596f0a | 315 | select NEED_SG_DMA_LENGTH |
87482708 | 316 | select NUMA_MEMBLKS if NUMA |
2eac9c2d | 317 | select PCI_DOMAINS if PCI |
625210cf | 318 | select PCI_LOCKLESS_CONFIG if PCI |
6471b825 | 319 | select PERF_EVENTS |
3195ef59 | 320 | select RTC_LIB |
d6faca40 | 321 | select RTC_MC146818_LIB |
6471b825 | 322 | select SPARSE_IRQ |
6471b825 | 323 | select SYSCTL_EXCEPTION_TRACE |
15f4eae7 | 324 | select THREAD_INFO_IN_TASK |
4aae683f | 325 | select TRACE_IRQFLAGS_SUPPORT |
4510bffb | 326 | select TRACE_IRQFLAGS_NMI_SUPPORT |
6471b825 | 327 | select USER_STACKTRACE_SUPPORT |
3b02a051 | 328 | select HAVE_ARCH_KCSAN if X86_64 |
0c608dad | 329 | select PROC_PID_ARCH_STATUS if PROC_FS |
50468e43 | 330 | select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX |
d49a0626 PZ |
331 | select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16 |
332 | select FUNCTION_ALIGNMENT_4B | |
9e2b4be3 | 333 | imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI |
ceea991a | 334 | select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE |
4817f70c | 335 | select ARCH_SUPPORTS_PT_RECLAIM if X86_64 |
7d8330a5 | 336 | |
ba7e4d13 | 337 | config INSTRUCTION_DECODER |
3120e25e JB |
338 | def_bool y |
339 | depends on KPROBES || PERF_EVENTS || UPROBES | |
ba7e4d13 | 340 | |
51b26ada LT |
341 | config OUTPUT_FORMAT |
342 | string | |
343 | default "elf32-i386" if X86_32 | |
344 | default "elf64-x86-64" if X86_64 | |
345 | ||
8d5fffb9 | 346 | config LOCKDEP_SUPPORT |
3c2362e6 | 347 | def_bool y |
8d5fffb9 SR |
348 | |
349 | config STACKTRACE_SUPPORT | |
3c2362e6 | 350 | def_bool y |
8d5fffb9 | 351 | |
8d5fffb9 | 352 | config MMU |
3c2362e6 | 353 | def_bool y |
8d5fffb9 | 354 | |
9e08f57d DC |
355 | config ARCH_MMAP_RND_BITS_MIN |
356 | default 28 if 64BIT | |
357 | default 8 | |
358 | ||
359 | config ARCH_MMAP_RND_BITS_MAX | |
360 | default 32 if 64BIT | |
361 | default 16 | |
362 | ||
363 | config ARCH_MMAP_RND_COMPAT_BITS_MIN | |
364 | default 8 | |
365 | ||
366 | config ARCH_MMAP_RND_COMPAT_BITS_MAX | |
367 | default 16 | |
368 | ||
8d5fffb9 SR |
369 | config SBUS |
370 | bool | |
371 | ||
372 | config GENERIC_ISA_DMA | |
3120e25e JB |
373 | def_bool y |
374 | depends on ISA_DMA_API | |
8d5fffb9 | 375 | |
d911c67e AP |
376 | config GENERIC_CSUM |
377 | bool | |
378 | default y if KMSAN || KASAN | |
379 | ||
8d5fffb9 | 380 | config GENERIC_BUG |
3c2362e6 | 381 | def_bool y |
8d5fffb9 | 382 | depends on BUG |
b93a531e JB |
383 | select GENERIC_BUG_RELATIVE_POINTERS if X86_64 |
384 | ||
385 | config GENERIC_BUG_RELATIVE_POINTERS | |
386 | bool | |
8d5fffb9 | 387 | |
8d5fffb9 | 388 | config ARCH_MAY_HAVE_PC_FDC |
3120e25e JB |
389 | def_bool y |
390 | depends on ISA_DMA_API | |
8d5fffb9 | 391 | |
1032c0ba SR |
392 | config GENERIC_CALIBRATE_DELAY |
393 | def_bool y | |
394 | ||
9a0b8415 | 395 | config ARCH_HAS_CPU_RELAX |
396 | def_bool y | |
397 | ||
801e4062 JB |
398 | config ARCH_HIBERNATION_POSSIBLE |
399 | def_bool y | |
801e4062 | 400 | |
f4cb5700 JB |
401 | config ARCH_SUSPEND_POSSIBLE |
402 | def_bool y | |
f4cb5700 | 403 | |
8d5fffb9 | 404 | config AUDIT_ARCH |
e0fd24a3 | 405 | def_bool y if X86_64 |
8d5fffb9 | 406 | |
d6f2d75a AR |
407 | config KASAN_SHADOW_OFFSET |
408 | hex | |
409 | depends on KASAN | |
410 | default 0xdffffc0000000000 | |
411 | ||
69575d38 SW |
412 | config HAVE_INTEL_TXT |
413 | def_bool y | |
6ea30386 | 414 | depends on INTEL_IOMMU && ACPI |
69575d38 | 415 | |
6b0c3d44 SR |
416 | config X86_64_SMP |
417 | def_bool y | |
418 | depends on X86_64 && SMP | |
419 | ||
2b144498 SD |
420 | config ARCH_SUPPORTS_UPROBES |
421 | def_bool y | |
422 | ||
d20642f0 RH |
423 | config FIX_EARLYCON_MEM |
424 | def_bool y | |
425 | ||
94d49eb3 KS |
426 | config DYNAMIC_PHYSICAL_MASK |
427 | bool | |
428 | ||
98233368 KS |
429 | config PGTABLE_LEVELS |
430 | int | |
7212b58d | 431 | default 5 if X86_64 |
98233368 KS |
432 | default 3 if X86_PAE |
433 | default 2 | |
434 | ||
506f1d07 SR |
435 | menu "Processor type and features" |
436 | ||
506f1d07 SR |
437 | config SMP |
438 | bool "Symmetric multi-processing support" | |
a7f7f624 | 439 | help |
506f1d07 | 440 | This enables support for systems with more than one CPU. If you have |
4a474157 RG |
441 | a system with only one CPU, say N. If you have a system with more |
442 | than one CPU, say Y. | |
506f1d07 | 443 | |
4a474157 | 444 | If you say N here, the kernel will run on uni- and multiprocessor |
506f1d07 SR |
445 | machines, but will use only one CPU of a multiprocessor machine. If |
446 | you say Y here, the kernel will run on many, but not all, | |
4a474157 | 447 | uniprocessor machines. On a uniprocessor machine, the kernel |
506f1d07 SR |
448 | will run faster if you say N here. |
449 | ||
450 | Note that if you say Y here and choose architecture "586" or | |
451 | "Pentium" under "Processor family", the kernel will not work on 486 | |
452 | architectures. Similarly, multiprocessor kernels for the "PPro" | |
453 | architecture may not work on all Pentium based boards. | |
454 | ||
455 | People using multiprocessor machines who say Y here should also say | |
456 | Y to "Enhanced Real Time Clock Support", below. The "Advanced Power | |
457 | Management" code will be disabled if you say Y here. | |
458 | ||
ff61f079 | 459 | See also <file:Documentation/arch/x86/i386/IO-APIC.rst>, |
4f4cfa6c | 460 | <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at |
506f1d07 SR |
461 | <http://www.tldp.org/docs.html#howto>. |
462 | ||
463 | If you don't know what to do here, say N. | |
464 | ||
06cd9a7d | 465 | config X86_X2APIC |
9232c49f | 466 | bool "x2APIC interrupt controller architecture support" |
19e3d60d | 467 | depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) |
9232c49f | 468 | default y |
a7f7f624 | 469 | help |
9232c49f MJ |
470 | x2APIC is an interrupt controller architecture, a component of which |
471 | (the local APIC) is present in the CPU. It allows faster access to | |
472 | the local APIC and supports a larger number of CPUs in the system | |
473 | than the predecessors. | |
06cd9a7d | 474 | |
9232c49f MJ |
475 | x2APIC was introduced in Intel CPUs around 2008 and in AMD EPYC CPUs |
476 | in 2019, but it can be disabled by the BIOS. It is also frequently | |
477 | emulated in virtual machines, even when the host CPU does not support | |
478 | it. Support in the CPU can be checked by executing | |
99bb1bd8 | 479 | grep x2apic /proc/cpuinfo |
06cd9a7d | 480 | |
99bb1bd8 MJ |
481 | If this configuration option is disabled, the kernel will boot with |
482 | very reduced functionality and performance on some platforms that | |
483 | have x2APIC enabled. On the other hand, on hardware that does not | |
484 | support x2APIC, a kernel with this option enabled will just fallback | |
485 | to older APIC implementations. | |
b8d1d163 | 486 | |
99bb1bd8 | 487 | If in doubt, say Y. |
06cd9a7d | 488 | |
7fec07fd JP |
489 | config X86_POSTED_MSI |
490 | bool "Enable MSI and MSI-x delivery by posted interrupts" | |
491 | depends on X86_64 && IRQ_REMAP | |
492 | help | |
493 | This enables MSIs that are under interrupt remapping to be delivered as | |
494 | posted interrupts to the host kernel. Interrupt throughput can | |
495 | potentially be improved by coalescing CPU notifications during high | |
496 | frequency bursts. | |
b8d1d163 | 497 | |
06cd9a7d YL |
498 | If you don't know what to do here, say N. |
499 | ||
6695c85b | 500 | config X86_MPPARSE |
4590d98f | 501 | bool "Enable MPS table" if ACPI |
7a527688 | 502 | default y |
5ab74722 | 503 | depends on X86_LOCAL_APIC |
a7f7f624 | 504 | help |
6695c85b YL |
505 | For old smp systems that do not have proper acpi support. Newer systems |
506 | (esp with 64bit cpus) with acpi support, MADT and DSDT will override it | |
6695c85b | 507 | |
e6d42931 JW |
508 | config X86_CPU_RESCTRL |
509 | bool "x86 CPU resource control support" | |
6fe07ce3 | 510 | depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) |
bff70402 JM |
511 | depends on MISC_FILESYSTEMS |
512 | select ARCH_HAS_CPU_RESCTRL | |
513 | select RESCTRL_FS | |
70288405 | 514 | select RESCTRL_FS_PSEUDO_LOCK |
78e99b4a | 515 | help |
e6d42931 | 516 | Enable x86 CPU resource control support. |
6fe07ce3 BM |
517 | |
518 | Provide support for the allocation and monitoring of system resources | |
519 | usage by the CPU. | |
520 | ||
521 | Intel calls this Intel Resource Director Technology | |
522 | (Intel(R) RDT). More information about RDT can be found in the | |
523 | Intel x86 Architecture Software Developer Manual. | |
524 | ||
525 | AMD calls this AMD Platform Quality of Service (AMD QoS). | |
526 | More information about AMD QoS can be found in the AMD64 Technology | |
527 | Platform Quality of Service Extensions manual. | |
78e99b4a FY |
528 | |
529 | Say N if unsure. | |
530 | ||
2cce9591 PAI |
531 | config X86_FRED |
532 | bool "Flexible Return and Event Delivery" | |
533 | depends on X86_64 | |
534 | help | |
535 | When enabled, try to use Flexible Return and Event Delivery | |
536 | instead of the legacy SYSCALL/SYSENTER/IDT architecture for | |
537 | ring transitions and exception/interrupt handling if the | |
3c41786c | 538 | system supports it. |
2cce9591 | 539 | |
c5c606d9 RT |
540 | config X86_EXTENDED_PLATFORM |
541 | bool "Support for extended (non-PC) x86 platforms" | |
542 | default y | |
a7f7f624 | 543 | help |
06ac8346 IM |
544 | If you disable this option then the kernel will only support |
545 | standard PC platforms. (which covers the vast majority of | |
546 | systems out there.) | |
547 | ||
8425091f | 548 | If you enable this option then you'll be able to select support |
71d99ea4 MY |
549 | for the following non-PC x86 platforms, depending on the value of |
550 | CONFIG_64BIT. | |
551 | ||
552 | 32-bit platforms (CONFIG_64BIT=n): | |
4047e877 MJ |
553 | Goldfish (mostly Android emulator) |
554 | Intel CE media processor (CE4100) SoC | |
4047e877 | 555 | Intel Quark |
8425091f | 556 | RDC R-321x SoC |
06ac8346 | 557 | |
71d99ea4 | 558 | 64-bit platforms (CONFIG_64BIT=y): |
44b111b5 | 559 | Numascale NumaChip |
8425091f RT |
560 | ScaleMP vSMP |
561 | SGI Ultraviolet | |
ca5955dd | 562 | Merrifield/Moorefield MID devices |
4047e877 | 563 | Goldfish (mostly Android emulator) |
8425091f RT |
564 | |
565 | If you have one of these systems, or if you want to build a | |
566 | generic distribution kernel, say Y here - otherwise say N. | |
71d99ea4 | 567 | |
c5c606d9 RT |
568 | # This is an alphabetically sorted list of 64 bit extended platforms |
569 | # Please maintain the alphabetic order if and when there are additions | |
44b111b5 SP |
570 | config X86_NUMACHIP |
571 | bool "Numascale NumaChip" | |
572 | depends on X86_64 | |
573 | depends on X86_EXTENDED_PLATFORM | |
574 | depends on NUMA | |
575 | depends on SMP | |
576 | depends on X86_X2APIC | |
f9726bfd | 577 | depends on PCI_MMCONFIG |
a7f7f624 | 578 | help |
44b111b5 SP |
579 | Adds support for Numascale NumaChip large-SMP systems. Needed to |
580 | enable more than ~168 cores. | |
581 | If you don't have one of these, you should say N here. | |
506f1d07 | 582 | |
c5c606d9 RT |
583 | config X86_VSMP |
584 | bool "ScaleMP vSMP" | |
6276a074 | 585 | select HYPERVISOR_GUEST |
c5c606d9 RT |
586 | select PARAVIRT |
587 | depends on X86_64 && PCI | |
588 | depends on X86_EXTENDED_PLATFORM | |
ead91d4b | 589 | depends on SMP |
a7f7f624 | 590 | help |
c5c606d9 RT |
591 | Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is |
592 | supposed to run on these EM64T-based machines. Only choose this option | |
593 | if you have one of these machines. | |
5e3a77e9 | 594 | |
03b48632 NP |
595 | config X86_UV |
596 | bool "SGI Ultraviolet" | |
597 | depends on X86_64 | |
c5c606d9 | 598 | depends on X86_EXTENDED_PLATFORM |
54c28d29 | 599 | depends on NUMA |
1ecb4ae5 | 600 | depends on EFI |
c2209ea5 | 601 | depends on KEXEC_CORE |
9d6c26e7 | 602 | depends on X86_X2APIC |
1222e564 | 603 | depends on PCI |
a7f7f624 | 604 | help |
03b48632 NP |
605 | This option is needed in order to support SGI Ultraviolet systems. |
606 | If you don't have one of these, you should say N here. | |
607 | ||
ca5955dd AB |
608 | config X86_INTEL_MID |
609 | bool "Intel Z34xx/Z35xx MID platform support" | |
610 | depends on X86_EXTENDED_PLATFORM | |
611 | depends on X86_PLATFORM_DEVICES | |
612 | depends on PCI | |
613 | depends on X86_64 || (EXPERT && PCI_GOANY) | |
614 | depends on X86_IO_APIC | |
615 | select I2C | |
616 | select DW_APB_TIMER | |
617 | select INTEL_SCU_PCI | |
618 | help | |
619 | Select to build a kernel capable of supporting 64-bit Intel MID | |
620 | (Mobile Internet Device) platform systems which do not have | |
621 | the PCI legacy interfaces. | |
622 | ||
623 | The only supported devices are the 22nm Merrified (Z34xx) | |
624 | and Moorefield (Z35xx) SoC used in the Intel Edison board and | |
625 | a small number of Android devices such as the Asus Zenfone 2, | |
626 | Asus FonePad 8 and Dell Venue 7. | |
627 | ||
628 | If you are building for a PC class system or non-MID tablet | |
629 | SoCs like Bay Trail (Z36xx/Z37xx), say N here. | |
630 | ||
631 | Intel MID platforms are based on an Intel processor and chipset which | |
632 | consume less power than most of the x86 derivatives. | |
506f1d07 | 633 | |
ddd70cf9 | 634 | config X86_GOLDFISH |
b03b016f KK |
635 | bool "Goldfish (Virtual Platform)" |
636 | depends on X86_EXTENDED_PLATFORM | |
a7f7f624 | 637 | help |
758cd94a JH |
638 | Enable support for the Goldfish virtual platform used primarily |
639 | for Android development. Unless you are building for the Android | |
640 | Goldfish emulator say N here. | |
ddd70cf9 | 641 | |
ca5955dd AB |
642 | # Following is an alphabetically sorted list of 32 bit extended platforms |
643 | # Please maintain the alphabetic order if and when there are additions | |
644 | ||
c751e17b TG |
645 | config X86_INTEL_CE |
646 | bool "CE4100 TV platform" | |
647 | depends on PCI | |
648 | depends on PCI_GODIRECT | |
6084a6e2 | 649 | depends on X86_IO_APIC |
c751e17b TG |
650 | depends on X86_32 |
651 | depends on X86_EXTENDED_PLATFORM | |
37bc9f50 | 652 | select X86_REBOOTFIXUPS |
da6b737b SAS |
653 | select OF |
654 | select OF_EARLY_FLATTREE | |
a7f7f624 | 655 | help |
c751e17b TG |
656 | Select for the Intel CE media processor (CE4100) SOC. |
657 | This option compiles in support for the CE4100 SOC for settop | |
658 | boxes and media devices. | |
659 | ||
8bbc2a13 BD |
660 | config X86_INTEL_QUARK |
661 | bool "Intel Quark platform support" | |
662 | depends on X86_32 | |
663 | depends on X86_EXTENDED_PLATFORM | |
664 | depends on X86_PLATFORM_DEVICES | |
665 | depends on X86_TSC | |
666 | depends on PCI | |
667 | depends on PCI_GOANY | |
668 | depends on X86_IO_APIC | |
669 | select IOSF_MBI | |
670 | select INTEL_IMR | |
9ab6eb51 | 671 | select COMMON_CLK |
a7f7f624 | 672 | help |
8bbc2a13 BD |
673 | Select to include support for Quark X1000 SoC. |
674 | Say Y here if you have a Quark based system such as the Arduino | |
675 | compatible Intel Galileo. | |
676 | ||
e35e328d MJ |
677 | config X86_RDC321X |
678 | bool "RDC R-321x SoC" | |
679 | depends on X86_32 | |
680 | depends on X86_EXTENDED_PLATFORM | |
681 | select M486 | |
682 | select X86_REBOOTFIXUPS | |
683 | help | |
684 | This option is needed for RDC R-321x system-on-chip, also known | |
685 | as R-8610-(G). | |
686 | If you don't have one of these chips, you should say N here. | |
687 | ||
3d48aab1 MW |
688 | config X86_INTEL_LPSS |
689 | bool "Intel Low Power Subsystem Support" | |
5962dd22 | 690 | depends on X86 && ACPI && PCI |
3d48aab1 | 691 | select COMMON_CLK |
0f531431 | 692 | select PINCTRL |
eebb3e8d | 693 | select IOSF_MBI |
a7f7f624 | 694 | help |
3d48aab1 MW |
695 | Select to build support for Intel Low Power Subsystem such as |
696 | found on Intel Lynxpoint PCH. Selecting this option enables | |
0f531431 MN |
697 | things like clock tree (common clock framework) and pincontrol |
698 | which are needed by the LPSS peripheral drivers. | |
3d48aab1 | 699 | |
92082a88 KX |
700 | config X86_AMD_PLATFORM_DEVICE |
701 | bool "AMD ACPI2Platform devices support" | |
702 | depends on ACPI | |
703 | select COMMON_CLK | |
704 | select PINCTRL | |
a7f7f624 | 705 | help |
92082a88 KX |
706 | Select to interpret AMD specific ACPI device to platform device |
707 | such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. | |
708 | I2C and UART depend on COMMON_CLK to set clock. GPIO driver is | |
709 | implemented under PINCTRL subsystem. | |
710 | ||
ced3ce76 DB |
711 | config IOSF_MBI |
712 | tristate "Intel SoC IOSF Sideband support for SoC platforms" | |
713 | depends on PCI | |
a7f7f624 | 714 | help |
ced3ce76 DB |
715 | This option enables sideband register access support for Intel SoC |
716 | platforms. On these platforms the IOSF sideband is used in lieu of | |
717 | MSR's for some register accesses, mostly but not limited to thermal | |
718 | and power. Drivers may query the availability of this device to | |
719 | determine if they need the sideband in order to work on these | |
720 | platforms. The sideband is available on the following SoC products. | |
721 | This list is not meant to be exclusive. | |
722 | - BayTrail | |
723 | - Braswell | |
724 | - Quark | |
725 | ||
726 | You should say Y if you are running a kernel on one of these SoC's. | |
727 | ||
ed2226bd DB |
728 | config IOSF_MBI_DEBUG |
729 | bool "Enable IOSF sideband access through debugfs" | |
730 | depends on IOSF_MBI && DEBUG_FS | |
a7f7f624 | 731 | help |
ed2226bd DB |
732 | Select this option to expose the IOSF sideband access registers (MCR, |
733 | MDR, MCRX) through debugfs to write and read register information from | |
734 | different units on the SoC. This is most useful for obtaining device | |
735 | state information for debug and analysis. As this is a general access | |
736 | mechanism, users of this option would have specific knowledge of the | |
737 | device they want to access. | |
738 | ||
739 | If you don't require the option or are in doubt, say N. | |
740 | ||
d949f36f | 741 | config X86_SUPPORTS_MEMORY_FAILURE |
6fc108a0 | 742 | def_bool y |
d949f36f LT |
743 | # MCE code calls memory_failure(): |
744 | depends on X86_MCE | |
745 | # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: | |
d949f36f LT |
746 | # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: |
747 | depends on X86_64 || !SPARSEMEM | |
748 | select ARCH_SUPPORTS_MEMORY_FAILURE | |
d949f36f | 749 | |
82148d1d S |
750 | config X86_32_IRIS |
751 | tristate "Eurobraille/Iris poweroff module" | |
752 | depends on X86_32 | |
a7f7f624 | 753 | help |
82148d1d S |
754 | The Iris machines from EuroBraille do not have APM or ACPI support |
755 | to shut themselves down properly. A special I/O sequence is | |
756 | needed to do so, which is what this module does at | |
757 | kernel shutdown. | |
758 | ||
759 | This is only for Iris machines from EuroBraille. | |
760 | ||
761 | If unused, say N. | |
762 | ||
ae1e9130 | 763 | config SCHED_OMIT_FRAME_POINTER |
3c2362e6 HH |
764 | def_bool y |
765 | prompt "Single-depth WCHAN output" | |
a87d0914 | 766 | depends on X86 |
a7f7f624 | 767 | help |
506f1d07 SR |
768 | Calculate simpler /proc/<PID>/wchan values. If this option |
769 | is disabled then wchan values will recurse back to the | |
770 | caller function. This provides more accurate wchan values, | |
771 | at the expense of slightly more scheduling overhead. | |
772 | ||
773 | If in doubt, say "Y". | |
774 | ||
6276a074 BP |
775 | menuconfig HYPERVISOR_GUEST |
776 | bool "Linux guest support" | |
a7f7f624 | 777 | help |
6276a074 BP |
778 | Say Y here to enable options for running Linux under various hyper- |
779 | visors. This option enables basic hypervisor detection and platform | |
780 | setup. | |
506f1d07 | 781 | |
6276a074 BP |
782 | If you say N, all options in this submenu will be skipped and |
783 | disabled, and Linux guest support won't be built in. | |
506f1d07 | 784 | |
6276a074 | 785 | if HYPERVISOR_GUEST |
506f1d07 | 786 | |
e61bd94a EPH |
787 | config PARAVIRT |
788 | bool "Enable paravirtualization code" | |
a0e2bf7c | 789 | depends on HAVE_STATIC_CALL |
a7f7f624 | 790 | help |
e61bd94a EPH |
791 | This changes the kernel so it can modify itself when it is run |
792 | under a hypervisor, potentially improving performance significantly | |
793 | over full virtualization. However, when run without a hypervisor | |
794 | the kernel is theoretically slower and slightly larger. | |
795 | ||
c00a280a JG |
796 | config PARAVIRT_XXL |
797 | bool | |
09230b75 | 798 | depends on X86_64 |
c00a280a | 799 | |
6276a074 BP |
800 | config PARAVIRT_DEBUG |
801 | bool "paravirt-ops debugging" | |
802 | depends on PARAVIRT && DEBUG_KERNEL | |
a7f7f624 | 803 | help |
6276a074 BP |
804 | Enable to debug paravirt_ops internals. Specifically, BUG if |
805 | a paravirt_op is missing when it is called. | |
806 | ||
b4ecc126 JF |
807 | config PARAVIRT_SPINLOCKS |
808 | bool "Paravirtualization layer for spinlocks" | |
6ea30386 | 809 | depends on PARAVIRT && SMP |
a7f7f624 | 810 | help |
b4ecc126 JF |
811 | Paravirtualized spinlocks allow a pvops backend to replace the |
812 | spinlock implementation with something virtualization-friendly | |
813 | (for example, block the virtual CPU rather than spinning). | |
814 | ||
4c4e4f61 R |
815 | It has a minimal impact on native kernels and gives a nice performance |
816 | benefit on paravirtualized KVM / Xen kernels. | |
b4ecc126 | 817 | |
4c4e4f61 | 818 | If you are unsure how to answer this question, answer Y. |
b4ecc126 | 819 | |
ecca2502 ZY |
820 | config X86_HV_CALLBACK_VECTOR |
821 | def_bool n | |
822 | ||
6276a074 | 823 | source "arch/x86/xen/Kconfig" |
7af192c9 | 824 | |
6276a074 BP |
825 | config KVM_GUEST |
826 | bool "KVM Guest support (including kvmclock)" | |
827 | depends on PARAVIRT | |
828 | select PARAVIRT_CLOCK | |
a1c4423b | 829 | select ARCH_CPUIDLE_HALTPOLL |
b1d40575 | 830 | select X86_HV_CALLBACK_VECTOR |
6276a074 | 831 | default y |
a7f7f624 | 832 | help |
6276a074 BP |
833 | This option enables various optimizations for running under the KVM |
834 | hypervisor. It includes a paravirtualized clock, so that instead | |
835 | of relying on a PIT (or probably other) emulation by the | |
836 | underlying device model, the host provides the guest with | |
837 | timing infrastructure such as time of day, and system time | |
506f1d07 | 838 | |
a1c4423b | 839 | config ARCH_CPUIDLE_HALTPOLL |
b03b016f KK |
840 | def_bool n |
841 | prompt "Disable host haltpoll when loading haltpoll driver" | |
842 | help | |
a1c4423b MT |
843 | If virtualized under KVM, disable host haltpoll. |
844 | ||
7733607f MW |
845 | config PVH |
846 | bool "Support for running PVH guests" | |
a7f7f624 | 847 | help |
7733607f MW |
848 | This option enables the PVH entry point for guest virtual machines |
849 | as specified in the x86/HVM direct boot ABI. | |
850 | ||
6276a074 BP |
851 | config PARAVIRT_TIME_ACCOUNTING |
852 | bool "Paravirtual steal time accounting" | |
853 | depends on PARAVIRT | |
a7f7f624 | 854 | help |
6276a074 BP |
855 | Select this option to enable fine granularity task steal time |
856 | accounting. Time spent executing other tasks in parallel with | |
857 | the current vCPU is discounted from the vCPU power. To account for | |
858 | that, there can be a small performance impact. | |
859 | ||
860 | If in doubt, say N here. | |
861 | ||
862 | config PARAVIRT_CLOCK | |
863 | bool | |
97349135 | 864 | |
4a362601 JK |
865 | config JAILHOUSE_GUEST |
866 | bool "Jailhouse non-root cell support" | |
abde587b | 867 | depends on X86_64 && PCI |
87e65d05 | 868 | select X86_PM_TIMER |
a7f7f624 | 869 | help |
4a362601 JK |
870 | This option allows to run Linux as guest in a Jailhouse non-root |
871 | cell. You can leave this option disabled if you only want to start | |
872 | Jailhouse and run Linux afterwards in the root cell. | |
873 | ||
ec7972c9 ZY |
874 | config ACRN_GUEST |
875 | bool "ACRN Guest support" | |
876 | depends on X86_64 | |
498ad393 | 877 | select X86_HV_CALLBACK_VECTOR |
ec7972c9 ZY |
878 | help |
879 | This option allows to run Linux as guest in the ACRN hypervisor. ACRN is | |
880 | a flexible, lightweight reference open-source hypervisor, built with | |
881 | real-time and safety-criticality in mind. It is built for embedded | |
882 | IOT with small footprint and real-time features. More details can be | |
883 | found in https://projectacrn.org/. | |
884 | ||
59bd54a8 KS |
885 | config INTEL_TDX_GUEST |
886 | bool "Intel TDX (Trust Domain Extensions) - Guest Support" | |
887 | depends on X86_64 && CPU_SUP_INTEL | |
888 | depends on X86_X2APIC | |
75d090fd | 889 | depends on EFI_STUB |
9f98a4f4 | 890 | depends on PARAVIRT |
41394e33 | 891 | select ARCH_HAS_CC_PLATFORM |
968b4931 | 892 | select X86_MEM_ENCRYPT |
77a512e3 | 893 | select X86_MCE |
75d090fd | 894 | select UNACCEPTED_MEMORY |
59bd54a8 KS |
895 | help |
896 | Support running as a guest under Intel TDX. Without this support, | |
897 | the guest kernel can not boot or run under TDX. | |
898 | TDX includes memory encryption and integrity capabilities | |
899 | which protect the confidentiality and integrity of guest | |
900 | memory contents and CPU state. TDX guests are protected from | |
901 | some attacks from the VMM. | |
902 | ||
758cd94a | 903 | endif # HYPERVISOR_GUEST |
97349135 | 904 | |
506f1d07 SR |
905 | source "arch/x86/Kconfig.cpu" |
906 | ||
907 | config HPET_TIMER | |
3c2362e6 | 908 | def_bool X86_64 |
506f1d07 | 909 | prompt "HPET Timer Support" if X86_32 |
a7f7f624 | 910 | help |
8f9ca475 IM |
911 | Use the IA-PC HPET (High Precision Event Timer) to manage |
912 | time in preference to the PIT and RTC, if a HPET is | |
913 | present. | |
914 | HPET is the next generation timer replacing legacy 8254s. | |
915 | The HPET provides a stable time base on SMP | |
916 | systems, unlike the TSC, but it is more expensive to access, | |
4e7f9df2 MT |
917 | as it is off-chip. The interface used is documented |
918 | in the HPET spec, revision 1. | |
506f1d07 | 919 | |
8f9ca475 IM |
920 | You can safely choose Y here. However, HPET will only be |
921 | activated if the platform and the BIOS support this feature. | |
922 | Otherwise the 8254 will be used for timing services. | |
506f1d07 | 923 | |
8f9ca475 | 924 | Choose N to continue using the legacy 8254 timer. |
506f1d07 SR |
925 | |
926 | config HPET_EMULATE_RTC | |
3c2362e6 | 927 | def_bool y |
3228e1dc | 928 | depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) |
506f1d07 | 929 | |
6a108a14 | 930 | # Mark as expert because too many people got it wrong. |
506f1d07 | 931 | # The code disables itself when not needed. |
7ae9392c TP |
932 | config DMI |
933 | default y | |
cf074402 | 934 | select DMI_SCAN_MACHINE_NON_EFI_FALLBACK |
6a108a14 | 935 | bool "Enable DMI scanning" if EXPERT |
a7f7f624 | 936 | help |
7ae9392c TP |
937 | Enabled scanning of DMI to identify machine quirks. Say Y |
938 | here unless you have verified that your setup is not | |
939 | affected by entries in the DMI blacklist. Required by PNP | |
940 | BIOS code. | |
941 | ||
506f1d07 | 942 | config GART_IOMMU |
38901f1c | 943 | bool "Old AMD GART IOMMU support" |
a4ce5a48 | 944 | select IOMMU_HELPER |
506f1d07 | 945 | select SWIOTLB |
23ac4ae8 | 946 | depends on X86_64 && PCI && AMD_NB |
a7f7f624 | 947 | help |
ced3c42c IM |
948 | Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron |
949 | GART based hardware IOMMUs. | |
950 | ||
951 | The GART supports full DMA access for devices with 32-bit access | |
952 | limitations, on systems with more than 3 GB. This is usually needed | |
953 | for USB, sound, many IDE/SATA chipsets and some other devices. | |
954 | ||
955 | Newer systems typically have a modern AMD IOMMU, supported via | |
956 | the CONFIG_AMD_IOMMU=y config option. | |
957 | ||
958 | In normal configurations this driver is only active when needed: | |
959 | there's more than 3 GB of memory and the system contains a | |
960 | 32-bit limited device. | |
961 | ||
962 | If unsure, say Y. | |
506f1d07 | 963 | |
8b766b0f MS |
964 | config BOOT_VESA_SUPPORT |
965 | bool | |
966 | help | |
967 | If true, at least one selected framebuffer driver can take advantage | |
968 | of VESA video modes set at an early boot stage via the vga= parameter. | |
506f1d07 | 969 | |
1184dc2f | 970 | config MAXSMP |
ddb0c5a6 | 971 | bool "Enable Maximum number of SMP Processors and NUMA Nodes" |
6ea30386 | 972 | depends on X86_64 && SMP && DEBUG_KERNEL |
36f5101a | 973 | select CPUMASK_OFFSTACK |
a7f7f624 | 974 | help |
ddb0c5a6 | 975 | Enable maximum number of CPUS and NUMA Nodes for this architecture. |
1184dc2f | 976 | If unsure, say N. |
506f1d07 | 977 | |
aec6487e IM |
978 | # |
979 | # The maximum number of CPUs supported: | |
980 | # | |
981 | # The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, | |
982 | # and which can be configured interactively in the | |
983 | # [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. | |
984 | # | |
985 | # The ranges are different on 32-bit and 64-bit kernels, depending on | |
986 | # hardware capabilities and scalability features of the kernel. | |
987 | # | |
988 | # ( If MAXSMP is enabled we just use the highest possible value and disable | |
989 | # interactive configuration. ) | |
990 | # | |
991 | ||
992 | config NR_CPUS_RANGE_BEGIN | |
a0d0bb4d | 993 | int |
aec6487e IM |
994 | default NR_CPUS_RANGE_END if MAXSMP |
995 | default 1 if !SMP | |
996 | default 2 | |
a0d0bb4d | 997 | |
aec6487e | 998 | config NR_CPUS_RANGE_END |
a0d0bb4d | 999 | int |
aec6487e | 1000 | depends on X86_32 |
0abf5086 | 1001 | default 8 if SMP |
aec6487e | 1002 | default 1 if !SMP |
a0d0bb4d | 1003 | |
aec6487e | 1004 | config NR_CPUS_RANGE_END |
a0d0bb4d | 1005 | int |
aec6487e | 1006 | depends on X86_64 |
1edae1ae SW |
1007 | default 8192 if SMP && CPUMASK_OFFSTACK |
1008 | default 512 if SMP && !CPUMASK_OFFSTACK | |
aec6487e | 1009 | default 1 if !SMP |
a0d0bb4d | 1010 | |
aec6487e | 1011 | config NR_CPUS_DEFAULT |
a0d0bb4d RD |
1012 | int |
1013 | depends on X86_32 | |
aec6487e IM |
1014 | default 8 if SMP |
1015 | default 1 if !SMP | |
a0d0bb4d | 1016 | |
aec6487e | 1017 | config NR_CPUS_DEFAULT |
a0d0bb4d RD |
1018 | int |
1019 | depends on X86_64 | |
aec6487e IM |
1020 | default 8192 if MAXSMP |
1021 | default 64 if SMP | |
1022 | default 1 if !SMP | |
a0d0bb4d | 1023 | |
506f1d07 | 1024 | config NR_CPUS |
36f5101a | 1025 | int "Maximum number of CPUs" if SMP && !MAXSMP |
aec6487e IM |
1026 | range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END |
1027 | default NR_CPUS_DEFAULT | |
a7f7f624 | 1028 | help |
506f1d07 | 1029 | This allows you to specify the maximum number of CPUs which this |
bb61ccc7 | 1030 | kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum |
cad14bb9 | 1031 | supported value is 8192, otherwise the maximum value is 512. The |
506f1d07 SR |
1032 | minimum value which makes sense is 2. |
1033 | ||
aec6487e IM |
1034 | This is purely to save memory: each supported CPU adds about 8KB |
1035 | to the kernel image. | |
506f1d07 | 1036 | |
66558b73 TC |
1037 | config SCHED_CLUSTER |
1038 | bool "Cluster scheduler support" | |
1039 | depends on SMP | |
1040 | default y | |
1041 | help | |
1042 | Cluster scheduler support improves the CPU scheduler's decision | |
1043 | making when dealing with machines that have clusters of CPUs. | |
1044 | Cluster usually means a couple of CPUs which are placed closely | |
1045 | by sharing mid-level caches, last-level cache tags or internal | |
1046 | busses. | |
1047 | ||
506f1d07 | 1048 | config SCHED_SMT |
dbe73364 | 1049 | def_bool y if SMP |
506f1d07 SR |
1050 | |
1051 | config SCHED_MC | |
3c2362e6 HH |
1052 | def_bool y |
1053 | prompt "Multi-core scheduler support" | |
c8e56d20 | 1054 | depends on SMP |
a7f7f624 | 1055 | help |
506f1d07 SR |
1056 | Multi-core scheduler support improves the CPU scheduler's decision |
1057 | making when dealing with multi-core CPU chips at a cost of slightly | |
1058 | increased overhead in some places. If unsure say N here. | |
1059 | ||
de966cf4 TC |
1060 | config SCHED_MC_PRIO |
1061 | bool "CPU core priorities scheduler support" | |
3598e577 ML |
1062 | depends on SCHED_MC |
1063 | select X86_INTEL_PSTATE if CPU_SUP_INTEL | |
1064 | select X86_AMD_PSTATE if CPU_SUP_AMD && ACPI | |
0a21fc12 | 1065 | select CPU_FREQ |
de966cf4 | 1066 | default y |
a7f7f624 | 1067 | help |
0a21fc12 IM |
1068 | Intel Turbo Boost Max Technology 3.0 enabled CPUs have a |
1069 | core ordering determined at manufacturing time, which allows | |
1070 | certain cores to reach higher turbo frequencies (when running | |
1071 | single threaded workloads) than others. | |
de966cf4 | 1072 | |
0a21fc12 IM |
1073 | Enabling this kernel feature teaches the scheduler about |
1074 | the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the | |
1075 | scheduler's CPU selection logic accordingly, so that higher | |
1076 | overall system performance can be achieved. | |
de966cf4 | 1077 | |
0a21fc12 | 1078 | This feature will have no effect on CPUs without this feature. |
de966cf4 | 1079 | |
0a21fc12 | 1080 | If unsure say Y here. |
5e76b2ab | 1081 | |
30b8b006 | 1082 | config UP_LATE_INIT |
b03b016f KK |
1083 | def_bool y |
1084 | depends on !SMP && X86_LOCAL_APIC | |
30b8b006 | 1085 | |
506f1d07 | 1086 | config X86_UP_APIC |
50849eef JB |
1087 | bool "Local APIC support on uniprocessors" if !PCI_MSI |
1088 | default PCI_MSI | |
dcbb01fb | 1089 | depends on X86_32 && !SMP |
a7f7f624 | 1090 | help |
506f1d07 SR |
1091 | A local APIC (Advanced Programmable Interrupt Controller) is an |
1092 | integrated interrupt controller in the CPU. If you have a single-CPU | |
1093 | system which has a processor with a local APIC, you can say Y here to | |
1094 | enable and use it. If you say Y here even though your machine doesn't | |
1095 | have a local APIC, then the kernel will still run with no slowdown at | |
1096 | all. The local APIC supports CPU-generated self-interrupts (timer, | |
1097 | performance counters), and the NMI watchdog which detects hard | |
1098 | lockups. | |
1099 | ||
1100 | config X86_UP_IOAPIC | |
1101 | bool "IO-APIC support on uniprocessors" | |
1102 | depends on X86_UP_APIC | |
a7f7f624 | 1103 | help |
506f1d07 SR |
1104 | An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an |
1105 | SMP-capable replacement for PC-style interrupt controllers. Most | |
1106 | SMP systems and many recent uniprocessor systems have one. | |
1107 | ||
1108 | If you have a single-CPU system with an IO-APIC, you can say Y here | |
1109 | to use it. If you say Y here even though your machine doesn't have | |
1110 | an IO-APIC, then the kernel will still run with no slowdown at all. | |
1111 | ||
1112 | config X86_LOCAL_APIC | |
3c2362e6 | 1113 | def_bool y |
dcbb01fb | 1114 | depends on X86_64 || SMP || X86_UP_APIC || PCI_MSI |
b5dc8e6c | 1115 | select IRQ_DOMAIN_HIERARCHY |
506f1d07 | 1116 | |
2b5e22af KS |
1117 | config ACPI_MADT_WAKEUP |
1118 | def_bool y | |
1119 | depends on X86_64 | |
1120 | depends on ACPI | |
1121 | depends on SMP | |
1122 | depends on X86_LOCAL_APIC | |
1123 | ||
506f1d07 | 1124 | config X86_IO_APIC |
b1da1e71 JB |
1125 | def_bool y |
1126 | depends on X86_LOCAL_APIC || X86_UP_IOAPIC | |
506f1d07 | 1127 | |
41b9eb26 SA |
1128 | config X86_REROUTE_FOR_BROKEN_BOOT_IRQS |
1129 | bool "Reroute for broken boot IRQs" | |
41b9eb26 | 1130 | depends on X86_IO_APIC |
a7f7f624 | 1131 | help |
41b9eb26 SA |
1132 | This option enables a workaround that fixes a source of |
1133 | spurious interrupts. This is recommended when threaded | |
1134 | interrupt handling is used on systems where the generation of | |
1135 | superfluous "boot interrupts" cannot be disabled. | |
1136 | ||
1137 | Some chipsets generate a legacy INTx "boot IRQ" when the IRQ | |
1138 | entry in the chipset's IO-APIC is masked (as, e.g. the RT | |
1139 | kernel does during interrupt handling). On chipsets where this | |
1140 | boot IRQ generation cannot be disabled, this workaround keeps | |
1141 | the original IRQ line masked so that only the equivalent "boot | |
1142 | IRQ" is delivered to the CPUs. The workaround also tells the | |
1143 | kernel to set up the IRQ handler on the boot IRQ line. In this | |
1144 | way only one interrupt is delivered to the kernel. Otherwise | |
1145 | the spurious second interrupt may cause the kernel to bring | |
1146 | down (vital) interrupt lines. | |
1147 | ||
1148 | Only affects "broken" chipsets. Interrupt sharing may be | |
1149 | increased on these systems. | |
1150 | ||
506f1d07 | 1151 | config X86_MCE |
bab9bc65 | 1152 | bool "Machine Check / overheating reporting" |
648ed940 | 1153 | select GENERIC_ALLOCATOR |
e57dbaf7 | 1154 | default y |
a7f7f624 | 1155 | help |
bab9bc65 AK |
1156 | Machine Check support allows the processor to notify the |
1157 | kernel if it detects a problem (e.g. overheating, data corruption). | |
506f1d07 | 1158 | The action the kernel takes depends on the severity of the problem, |
bab9bc65 | 1159 | ranging from warning messages to halting the machine. |
4efc0670 | 1160 | |
5de97c9f TL |
1161 | config X86_MCELOG_LEGACY |
1162 | bool "Support for deprecated /dev/mcelog character device" | |
1163 | depends on X86_MCE | |
a7f7f624 | 1164 | help |
5de97c9f TL |
1165 | Enable support for /dev/mcelog which is needed by the old mcelog |
1166 | userspace logging daemon. Consider switching to the new generation | |
1167 | rasdaemon solution. | |
1168 | ||
506f1d07 | 1169 | config X86_MCE_INTEL |
3c2362e6 HH |
1170 | def_bool y |
1171 | prompt "Intel MCE features" | |
c1ebf835 | 1172 | depends on X86_MCE && X86_LOCAL_APIC |
a7f7f624 | 1173 | help |
758cd94a JH |
1174 | Additional support for intel specific MCE features such as |
1175 | the thermal monitor. | |
506f1d07 SR |
1176 | |
1177 | config X86_MCE_AMD | |
3c2362e6 HH |
1178 | def_bool y |
1179 | prompt "AMD MCE features" | |
d35fb312 | 1180 | depends on X86_MCE && X86_LOCAL_APIC |
a7f7f624 | 1181 | help |
758cd94a JH |
1182 | Additional support for AMD specific MCE features such as |
1183 | the DRAM Error Threshold. | |
506f1d07 | 1184 | |
4efc0670 | 1185 | config X86_ANCIENT_MCE |
6fc108a0 | 1186 | bool "Support for old Pentium 5 / WinChip machine checks" |
c31d9633 | 1187 | depends on X86_32 && X86_MCE |
a7f7f624 | 1188 | help |
cd13adcc | 1189 | Include support for machine check handling on old Pentium 5 or WinChip |
5065a706 | 1190 | systems. These typically need to be enabled explicitly on the command |
cd13adcc | 1191 | line. |
4efc0670 | 1192 | |
b2762686 AK |
1193 | config X86_MCE_THRESHOLD |
1194 | depends on X86_MCE_AMD || X86_MCE_INTEL | |
6fc108a0 | 1195 | def_bool y |
b2762686 | 1196 | |
ea149b36 | 1197 | config X86_MCE_INJECT |
bc8e80d5 | 1198 | depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS |
ea149b36 | 1199 | tristate "Machine check injector support" |
a7f7f624 | 1200 | help |
ea149b36 AK |
1201 | Provide support for injecting machine checks for testing purposes. |
1202 | If you don't know what a machine check is and you don't do kernel | |
1203 | QA it is safe to say n. | |
1204 | ||
07dc900e | 1205 | source "arch/x86/events/Kconfig" |
e633c65a | 1206 | |
5aef51c3 | 1207 | config X86_LEGACY_VM86 |
1e642812 | 1208 | bool "Legacy VM86 support" |
506f1d07 | 1209 | depends on X86_32 |
a7f7f624 | 1210 | help |
5aef51c3 AL |
1211 | This option allows user programs to put the CPU into V8086 |
1212 | mode, which is an 80286-era approximation of 16-bit real mode. | |
1213 | ||
1214 | Some very old versions of X and/or vbetool require this option | |
1215 | for user mode setting. Similarly, DOSEMU will use it if | |
1216 | available to accelerate real mode DOS programs. However, any | |
1217 | recent version of DOSEMU, X, or vbetool should be fully | |
1218 | functional even without kernel VM86 support, as they will all | |
1e642812 IM |
1219 | fall back to software emulation. Nevertheless, if you are using |
1220 | a 16-bit DOS program where 16-bit performance matters, vm86 | |
1221 | mode might be faster than emulation and you might want to | |
1222 | enable this option. | |
5aef51c3 | 1223 | |
1e642812 IM |
1224 | Note that any app that works on a 64-bit kernel is unlikely to |
1225 | need this option, as 64-bit kernels don't, and can't, support | |
1226 | V8086 mode. This option is also unrelated to 16-bit protected | |
1227 | mode and is not needed to run most 16-bit programs under Wine. | |
5aef51c3 | 1228 | |
1e642812 IM |
1229 | Enabling this option increases the complexity of the kernel |
1230 | and slows down exception handling a tiny bit. | |
5aef51c3 | 1231 | |
1e642812 | 1232 | If unsure, say N here. |
5aef51c3 AL |
1233 | |
1234 | config VM86 | |
b03b016f KK |
1235 | bool |
1236 | default X86_LEGACY_VM86 | |
34273f41 PA |
1237 | |
1238 | config X86_16BIT | |
1239 | bool "Enable support for 16-bit segments" if EXPERT | |
1240 | default y | |
a5b9e5a2 | 1241 | depends on MODIFY_LDT_SYSCALL |
a7f7f624 | 1242 | help |
34273f41 PA |
1243 | This option is required by programs like Wine to run 16-bit |
1244 | protected mode legacy code on x86 processors. Disabling | |
1245 | this option saves about 300 bytes on i386, or around 6K text | |
1246 | plus 16K runtime memory on x86-64, | |
1247 | ||
1248 | config X86_ESPFIX32 | |
1249 | def_bool y | |
1250 | depends on X86_16BIT && X86_32 | |
506f1d07 | 1251 | |
197725de PA |
1252 | config X86_ESPFIX64 |
1253 | def_bool y | |
34273f41 | 1254 | depends on X86_16BIT && X86_64 |
506f1d07 | 1255 | |
1ad83c85 | 1256 | config X86_VSYSCALL_EMULATION |
b03b016f KK |
1257 | bool "Enable vsyscall emulation" if EXPERT |
1258 | default y | |
1259 | depends on X86_64 | |
a7f7f624 | 1260 | help |
758cd94a JH |
1261 | This enables emulation of the legacy vsyscall page. Disabling |
1262 | it is roughly equivalent to booting with vsyscall=none, except | |
1263 | that it will also disable the helpful warning if a program | |
1264 | tries to use a vsyscall. With this option set to N, offending | |
1265 | programs will just segfault, citing addresses of the form | |
1266 | 0xffffffffff600?00. | |
1ad83c85 | 1267 | |
758cd94a JH |
1268 | This option is required by many programs built before 2013, and |
1269 | care should be used even with newer programs if set to N. | |
1ad83c85 | 1270 | |
758cd94a JH |
1271 | Disabling this option saves about 7K of kernel size and |
1272 | possibly 4K of additional runtime pagetable memory. | |
1ad83c85 | 1273 | |
111e7b15 TG |
1274 | config X86_IOPL_IOPERM |
1275 | bool "IOPERM and IOPL Emulation" | |
a24ca997 | 1276 | default y |
a7f7f624 | 1277 | help |
111e7b15 TG |
1278 | This enables the ioperm() and iopl() syscalls which are necessary |
1279 | for legacy applications. | |
1280 | ||
c8137ace TG |
1281 | Legacy IOPL support is an overbroad mechanism which allows user |
1282 | space aside of accessing all 65536 I/O ports also to disable | |
1283 | interrupts. To gain this access the caller needs CAP_SYS_RAWIO | |
1284 | capabilities and permission from potentially active security | |
1285 | modules. | |
1286 | ||
1287 | The emulation restricts the functionality of the syscall to | |
1288 | only allowing the full range I/O port access, but prevents the | |
a24ca997 TG |
1289 | ability to disable interrupts from user space which would be |
1290 | granted if the hardware IOPL mechanism would be used. | |
c8137ace | 1291 | |
506f1d07 SR |
1292 | config TOSHIBA |
1293 | tristate "Toshiba Laptop support" | |
1294 | depends on X86_32 | |
a7f7f624 | 1295 | help |
506f1d07 SR |
1296 | This adds a driver to safely access the System Management Mode of |
1297 | the CPU on Toshiba portables with a genuine Toshiba BIOS. It does | |
1298 | not work on models with a Phoenix BIOS. The System Management Mode | |
1299 | is used to set the BIOS and power saving options on Toshiba portables. | |
1300 | ||
1301 | For information on utilities to make use of this driver see the | |
1302 | Toshiba Linux utilities web site at: | |
1303 | <http://www.buzzard.org.uk/toshiba/>. | |
1304 | ||
1305 | Say Y if you intend to run this kernel on a Toshiba portable. | |
1306 | Say N otherwise. | |
1307 | ||
506f1d07 | 1308 | config X86_REBOOTFIXUPS |
9ba16087 JB |
1309 | bool "Enable X86 board specific fixups for reboot" |
1310 | depends on X86_32 | |
a7f7f624 | 1311 | help |
506f1d07 SR |
1312 | This enables chipset and/or board specific fixups to be done |
1313 | in order to get reboot to work correctly. This is only needed on | |
1314 | some combinations of hardware and BIOS. The symptom, for which | |
1315 | this config is intended, is when reboot ends with a stalled/hung | |
1316 | system. | |
1317 | ||
1318 | Currently, the only fixup is for the Geode machines using | |
5e3a77e9 | 1319 | CS5530A and CS5536 chipsets and the RDC R-321x SoC. |
506f1d07 SR |
1320 | |
1321 | Say Y if you want to enable the fixup. Currently, it's safe to | |
1322 | enable this option even if you don't need it. | |
1323 | Say N otherwise. | |
1324 | ||
1325 | config MICROCODE | |
e6bcfdd7 | 1326 | def_bool y |
80030e3d | 1327 | depends on CPU_SUP_AMD || CPU_SUP_INTEL |
50cef76d | 1328 | select CRYPTO_LIB_SHA256 if CPU_SUP_AMD |
80cc9f10 | 1329 | |
fdbd4381 TG |
1330 | config MICROCODE_INITRD32 |
1331 | def_bool y | |
1332 | depends on MICROCODE && X86_32 && BLK_DEV_INITRD | |
1333 | ||
a77a94f8 BP |
1334 | config MICROCODE_LATE_LOADING |
1335 | bool "Late microcode loading (DANGEROUS)" | |
c02f48e0 | 1336 | default n |
634ac23a | 1337 | depends on MICROCODE && SMP |
a7f7f624 | 1338 | help |
a77a94f8 BP |
1339 | Loading microcode late, when the system is up and executing instructions |
1340 | is a tricky business and should be avoided if possible. Just the sequence | |
1341 | of synchronizing all cores and SMT threads is one fragile dance which does | |
1342 | not guarantee that cores might not softlock after the loading. Therefore, | |
9407bda8 TG |
1343 | use this at your own risk. Late loading taints the kernel unless the |
1344 | microcode header indicates that it is safe for late loading via the | |
1345 | minimal revision check. This minimal revision check can be enforced on | |
1346 | the kernel command line with "microcode.minrev=Y". | |
1347 | ||
1348 | config MICROCODE_LATE_FORCE_MINREV | |
1349 | bool "Enforce late microcode loading minimal revision check" | |
1350 | default n | |
1351 | depends on MICROCODE_LATE_LOADING | |
1352 | help | |
1353 | To prevent that users load microcode late which modifies already | |
1354 | in use features, newer microcode patches have a minimum revision field | |
1355 | in the microcode header, which tells the kernel which minimum | |
1356 | revision must be active in the CPU to safely load that new microcode | |
1357 | late into the running system. If disabled the check will not | |
1358 | be enforced but the kernel will be tainted when the minimal | |
1359 | revision check fails. | |
1360 | ||
1361 | This minimal revision check can also be controlled via the | |
1362 | "microcode.minrev" parameter on the kernel command line. | |
1363 | ||
1364 | If unsure say Y. | |
506f1d07 SR |
1365 | |
1366 | config X86_MSR | |
1367 | tristate "/dev/cpu/*/msr - Model-specific register support" | |
a7f7f624 | 1368 | help |
506f1d07 SR |
1369 | This device gives privileged processes access to the x86 |
1370 | Model-Specific Registers (MSRs). It is a character device with | |
1371 | major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. | |
1372 | MSR accesses are directed to a specific CPU on multi-processor | |
1373 | systems. | |
1374 | ||
1375 | config X86_CPUID | |
1376 | tristate "/dev/cpu/*/cpuid - CPU information support" | |
a7f7f624 | 1377 | help |
506f1d07 SR |
1378 | This device gives processes access to the x86 CPUID instruction to |
1379 | be executed on a specific processor. It is a character device | |
1380 | with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to | |
1381 | /dev/cpu/31/cpuid. | |
1382 | ||
bbeb69ce AB |
1383 | config HIGHMEM4G |
1384 | bool "High Memory Support" | |
506f1d07 | 1385 | depends on X86_32 |
a7f7f624 | 1386 | help |
bbeb69ce | 1387 | Linux can use up to 4 Gigabytes of physical memory on x86 systems. |
506f1d07 SR |
1388 | However, the address space of 32-bit x86 processors is only 4 |
1389 | Gigabytes large. That means that, if you have a large amount of | |
1390 | physical memory, not all of it can be "permanently mapped" by the | |
1391 | kernel. The physical memory that's not permanently mapped is called | |
1392 | "high memory". | |
1393 | ||
1394 | If you are compiling a kernel which will never run on a machine with | |
1395 | more than 1 Gigabyte total physical RAM, answer "off" here (default | |
1396 | choice and suitable for most users). This will result in a "3GB/1GB" | |
1397 | split: 3GB are mapped so that each process sees a 3GB virtual memory | |
1398 | space and the remaining part of the 4GB virtual memory space is used | |
1399 | by the kernel to permanently map as much physical memory as | |
1400 | possible. | |
1401 | ||
1402 | If the machine has between 1 and 4 Gigabytes physical RAM, then | |
bbeb69ce | 1403 | answer "Y" here. |
506f1d07 | 1404 | |
bbeb69ce | 1405 | If unsure, say N. |
506f1d07 SR |
1406 | |
1407 | choice | |
6a108a14 | 1408 | prompt "Memory split" if EXPERT |
506f1d07 SR |
1409 | default VMSPLIT_3G |
1410 | depends on X86_32 | |
a7f7f624 | 1411 | help |
506f1d07 SR |
1412 | Select the desired split between kernel and user memory. |
1413 | ||
1414 | If the address range available to the kernel is less than the | |
1415 | physical memory installed, the remaining memory will be available | |
1416 | as "high memory". Accessing high memory is a little more costly | |
1417 | than low memory, as it needs to be mapped into the kernel first. | |
1418 | Note that increasing the kernel address space limits the range | |
1419 | available to user programs, making the address space there | |
1420 | tighter. Selecting anything other than the default 3G/1G split | |
1421 | will also likely make your kernel incompatible with binary-only | |
1422 | kernel modules. | |
1423 | ||
1424 | If you are not absolutely sure what you are doing, leave this | |
1425 | option alone! | |
1426 | ||
1427 | config VMSPLIT_3G | |
1428 | bool "3G/1G user/kernel split" | |
1429 | config VMSPLIT_3G_OPT | |
1430 | depends on !X86_PAE | |
1431 | bool "3G/1G user/kernel split (for full 1G low memory)" | |
1432 | config VMSPLIT_2G | |
1433 | bool "2G/2G user/kernel split" | |
1434 | config VMSPLIT_2G_OPT | |
1435 | depends on !X86_PAE | |
1436 | bool "2G/2G user/kernel split (for full 2G low memory)" | |
1437 | config VMSPLIT_1G | |
1438 | bool "1G/3G user/kernel split" | |
1439 | endchoice | |
1440 | ||
1441 | config PAGE_OFFSET | |
1442 | hex | |
1443 | default 0xB0000000 if VMSPLIT_3G_OPT | |
1444 | default 0x80000000 if VMSPLIT_2G | |
1445 | default 0x78000000 if VMSPLIT_2G_OPT | |
1446 | default 0x40000000 if VMSPLIT_1G | |
1447 | default 0xC0000000 | |
1448 | depends on X86_32 | |
1449 | ||
1450 | config HIGHMEM | |
bbeb69ce | 1451 | def_bool HIGHMEM4G |
506f1d07 SR |
1452 | |
1453 | config X86_PAE | |
9ba16087 | 1454 | bool "PAE (Physical Address Extension) Support" |
88a2b4ed | 1455 | depends on X86_32 && X86_HAVE_PAE |
d4a451d5 | 1456 | select PHYS_ADDR_T_64BIT |
a7f7f624 | 1457 | help |
506f1d07 SR |
1458 | PAE is required for NX support, and furthermore enables |
1459 | larger swapspace support for non-overcommit purposes. It | |
1460 | has the cost of more pagetable lookup overhead, and also | |
1461 | consumes more pagetable space per process. | |
1462 | ||
10971ab2 | 1463 | config X86_DIRECT_GBPAGES |
e5008abe | 1464 | def_bool y |
2e1da13f | 1465 | depends on X86_64 |
a7f7f624 | 1466 | help |
10971ab2 IM |
1467 | Certain kernel features effectively disable kernel |
1468 | linear 1 GB mappings (even if the CPU otherwise | |
1469 | supports them), so don't confuse the user by printing | |
1470 | that we have them enabled. | |
9e899816 | 1471 | |
5c280cf6 TG |
1472 | config X86_CPA_STATISTICS |
1473 | bool "Enable statistic for Change Page Attribute" | |
1474 | depends on DEBUG_FS | |
a7f7f624 | 1475 | help |
b75baaf3 | 1476 | Expose statistics about the Change Page Attribute mechanism, which |
a943245a | 1477 | helps to determine the effectiveness of preserving large and huge |
5c280cf6 TG |
1478 | page mappings when mapping protections are changed. |
1479 | ||
20f07a04 KS |
1480 | config X86_MEM_ENCRYPT |
1481 | select ARCH_HAS_FORCE_DMA_UNENCRYPTED | |
1482 | select DYNAMIC_PHYSICAL_MASK | |
20f07a04 KS |
1483 | def_bool n |
1484 | ||
7744ccdb TL |
1485 | config AMD_MEM_ENCRYPT |
1486 | bool "AMD Secure Memory Encryption (SME) support" | |
1487 | depends on X86_64 && CPU_SUP_AMD | |
6c321179 | 1488 | depends on EFI_STUB |
82fef0ad | 1489 | select DMA_COHERENT_POOL |
ce9084ba | 1490 | select ARCH_USE_MEMREMAP_PROT |
597cfe48 | 1491 | select INSTRUCTION_DECODER |
aa5a4611 | 1492 | select ARCH_HAS_CC_PLATFORM |
20f07a04 | 1493 | select X86_MEM_ENCRYPT |
6c321179 | 1494 | select UNACCEPTED_MEMORY |
c5529418 | 1495 | select CRYPTO_LIB_AESGCM |
a7f7f624 | 1496 | help |
7744ccdb TL |
1497 | Say yes to enable support for the encryption of system memory. |
1498 | This requires an AMD processor that supports Secure Memory | |
1499 | Encryption (SME). | |
1500 | ||
506f1d07 SR |
1501 | # Common NUMA Features |
1502 | config NUMA | |
e133f6ea | 1503 | bool "NUMA Memory Allocation and Scheduler Support" |
506f1d07 | 1504 | depends on SMP |
0abf5086 | 1505 | depends on X86_64 |
7ecd19cf | 1506 | select USE_PERCPU_NUMA_NODE_ID |
0c436a58 | 1507 | select OF_NUMA if OF |
a7f7f624 | 1508 | help |
e133f6ea | 1509 | Enable NUMA (Non-Uniform Memory Access) support. |
fd51b2d7 | 1510 | |
506f1d07 SR |
1511 | The kernel will try to allocate memory used by a CPU on the |
1512 | local memory controller of the CPU and add some more | |
1513 | NUMA awareness to the kernel. | |
1514 | ||
c280ea5e | 1515 | For 64-bit this is recommended if the system is Intel Core i7 |
fd51b2d7 KM |
1516 | (or later), AMD Opteron, or EM64T NUMA. |
1517 | ||
fd51b2d7 | 1518 | Otherwise, you should say N. |
506f1d07 | 1519 | |
eec1d4fa | 1520 | config AMD_NUMA |
3c2362e6 HH |
1521 | def_bool y |
1522 | prompt "Old style AMD Opteron NUMA detection" | |
5da0ef9a | 1523 | depends on X86_64 && NUMA && PCI |
a7f7f624 | 1524 | help |
eec1d4fa HR |
1525 | Enable AMD NUMA node topology detection. You should say Y here if |
1526 | you have a multi processor AMD system. This uses an old method to | |
1527 | read the NUMA configuration directly from the builtin Northbridge | |
1528 | of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, | |
1529 | which also takes priority if both are compiled in. | |
506f1d07 SR |
1530 | |
1531 | config X86_64_ACPI_NUMA | |
3c2362e6 HH |
1532 | def_bool y |
1533 | prompt "ACPI NUMA detection" | |
506f1d07 SR |
1534 | depends on X86_64 && NUMA && ACPI && PCI |
1535 | select ACPI_NUMA | |
a7f7f624 | 1536 | help |
506f1d07 SR |
1537 | Enable ACPI SRAT based node topology detection. |
1538 | ||
506f1d07 | 1539 | config NODES_SHIFT |
d25e26b6 | 1540 | int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP |
51591e31 DR |
1541 | range 1 10 |
1542 | default "10" if MAXSMP | |
506f1d07 | 1543 | default "6" if X86_64 |
506f1d07 | 1544 | default "3" |
a9ee6cf5 | 1545 | depends on NUMA |
a7f7f624 | 1546 | help |
1184dc2f | 1547 | Specify the maximum number of NUMA Nodes available on the target |
692105b8 | 1548 | system. Increases memory reserved to accommodate various tables. |
506f1d07 | 1549 | |
506f1d07 SR |
1550 | config ARCH_FLATMEM_ENABLE |
1551 | def_bool y | |
3b16651f | 1552 | depends on X86_32 && !NUMA |
506f1d07 | 1553 | |
506f1d07 SR |
1554 | config ARCH_SPARSEMEM_ENABLE |
1555 | def_bool y | |
506f1d07 SR |
1556 | select SPARSEMEM_STATIC if X86_32 |
1557 | select SPARSEMEM_VMEMMAP_ENABLE if X86_64 | |
cba5d9b3 | 1558 | select SPARSEMEM_VMEMMAP if X86_64 |
506f1d07 | 1559 | |
3b16651f | 1560 | config ARCH_SPARSEMEM_DEFAULT |
6ad57f7f | 1561 | def_bool X86_64 || (NUMA && X86_32) |
3b16651f | 1562 | |
506f1d07 SR |
1563 | config ARCH_SELECT_MEMORY_MODEL |
1564 | def_bool y | |
4eda2bc3 | 1565 | depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE |
506f1d07 SR |
1566 | |
1567 | config ARCH_MEMORY_PROBE | |
a0842b70 | 1568 | bool "Enable sysfs memory/probe interface" |
5c11f00b | 1569 | depends on MEMORY_HOTPLUG |
a0842b70 TK |
1570 | help |
1571 | This option enables a sysfs memory/probe interface for testing. | |
cb1aaebe | 1572 | See Documentation/admin-guide/mm/memory-hotplug.rst for more information. |
a0842b70 | 1573 | If you are unsure how to answer this question, answer N. |
506f1d07 | 1574 | |
3b16651f TH |
1575 | config ARCH_PROC_KCORE_TEXT |
1576 | def_bool y | |
1577 | depends on X86_64 && PROC_KCORE | |
1578 | ||
a29815a3 | 1579 | config ILLEGAL_POINTER_VALUE |
b03b016f KK |
1580 | hex |
1581 | default 0 if X86_32 | |
1582 | default 0xdead000000000000 if X86_64 | |
a29815a3 | 1583 | |
7a67832c DW |
1584 | config X86_PMEM_LEGACY_DEVICE |
1585 | bool | |
1586 | ||
ec776ef6 | 1587 | config X86_PMEM_LEGACY |
7a67832c | 1588 | tristate "Support non-standard NVDIMMs and ADR protected memory" |
9f53f9fa DW |
1589 | depends on PHYS_ADDR_T_64BIT |
1590 | depends on BLK_DEV | |
7a67832c | 1591 | select X86_PMEM_LEGACY_DEVICE |
7b27a862 | 1592 | select NUMA_KEEP_MEMINFO if NUMA |
9f53f9fa | 1593 | select LIBNVDIMM |
ec776ef6 CH |
1594 | help |
1595 | Treat memory marked using the non-standard e820 type of 12 as used | |
1596 | by the Intel Sandy Bridge-EP reference BIOS as protected memory. | |
1597 | The kernel will offer these regions to the 'pmem' driver so | |
1598 | they can be used for persistent storage. | |
1599 | ||
1600 | Say Y if unsure. | |
1601 | ||
9f077871 | 1602 | config X86_CHECK_BIOS_CORRUPTION |
8f9ca475 | 1603 | bool "Check for low memory corruption" |
a7f7f624 | 1604 | help |
8f9ca475 IM |
1605 | Periodically check for memory corruption in low memory, which |
1606 | is suspected to be caused by BIOS. Even when enabled in the | |
1607 | configuration, it is disabled at runtime. Enable it by | |
1608 | setting "memory_corruption_check=1" on the kernel command | |
1609 | line. By default it scans the low 64k of memory every 60 | |
1610 | seconds; see the memory_corruption_check_size and | |
1611 | memory_corruption_check_period parameters in | |
8c27ceff | 1612 | Documentation/admin-guide/kernel-parameters.rst to adjust this. |
8f9ca475 IM |
1613 | |
1614 | When enabled with the default parameters, this option has | |
1615 | almost no overhead, as it reserves a relatively small amount | |
1616 | of memory and scans it infrequently. It both detects corruption | |
1617 | and prevents it from affecting the running system. | |
1618 | ||
1619 | It is, however, intended as a diagnostic tool; if repeatable | |
1620 | BIOS-originated corruption always affects the same memory, | |
1621 | you can use memmap= to prevent the kernel from using that | |
1622 | memory. | |
9f077871 | 1623 | |
c885df50 | 1624 | config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK |
8f9ca475 | 1625 | bool "Set the default setting of memory_corruption_check" |
c885df50 JF |
1626 | depends on X86_CHECK_BIOS_CORRUPTION |
1627 | default y | |
a7f7f624 | 1628 | help |
8f9ca475 IM |
1629 | Set whether the default state of memory_corruption_check is |
1630 | on or off. | |
c885df50 | 1631 | |
506f1d07 SR |
1632 | config MATH_EMULATION |
1633 | bool | |
a5b9e5a2 | 1634 | depends on MODIFY_LDT_SYSCALL |
87d6021b | 1635 | prompt "Math emulation" if X86_32 && (M486SX || MELAN) |
a7f7f624 | 1636 | help |
506f1d07 SR |
1637 | Linux can emulate a math coprocessor (used for floating point |
1638 | operations) if you don't have one. 486DX and Pentium processors have | |
1639 | a math coprocessor built in, 486SX and 386 do not, unless you added | |
1640 | a 487DX or 387, respectively. (The messages during boot time can | |
1641 | give you some hints here ["man dmesg"].) Everyone needs either a | |
1642 | coprocessor or this emulation. | |
1643 | ||
1644 | If you don't have a math coprocessor, you need to say Y here; if you | |
1645 | say Y here even though you have a coprocessor, the coprocessor will | |
1646 | be used nevertheless. (This behavior can be changed with the kernel | |
1647 | command line option "no387", which comes handy if your coprocessor | |
1648 | is broken. Try "man bootparam" or see the documentation of your boot | |
1649 | loader (lilo or loadlin) about how to pass options to the kernel at | |
1650 | boot time.) This means that it is a good idea to say Y here if you | |
1651 | intend to use this kernel on different machines. | |
1652 | ||
1653 | More information about the internals of the Linux math coprocessor | |
1654 | emulation can be found in <file:arch/x86/math-emu/README>. | |
1655 | ||
1656 | If you are not sure, say Y; apart from resulting in a 66 KB bigger | |
1657 | kernel, it won't hurt. | |
1658 | ||
1659 | config MTRR | |
6fc108a0 | 1660 | def_bool y |
6a108a14 | 1661 | prompt "MTRR (Memory Type Range Register) support" if EXPERT |
a7f7f624 | 1662 | help |
506f1d07 SR |
1663 | On Intel P6 family processors (Pentium Pro, Pentium II and later) |
1664 | the Memory Type Range Registers (MTRRs) may be used to control | |
1665 | processor access to memory ranges. This is most useful if you have | |
1666 | a video (VGA) card on a PCI or AGP bus. Enabling write-combining | |
1667 | allows bus write transfers to be combined into a larger transfer | |
1668 | before bursting over the PCI/AGP bus. This can increase performance | |
1669 | of image write operations 2.5 times or more. Saying Y here creates a | |
1670 | /proc/mtrr file which may be used to manipulate your processor's | |
1671 | MTRRs. Typically the X server should use this. | |
1672 | ||
1673 | This code has a reasonably generic interface so that similar | |
1674 | control registers on other processors can be easily supported | |
1675 | as well: | |
1676 | ||
1677 | The Cyrix 6x86, 6x86MX and M II processors have Address Range | |
1678 | Registers (ARRs) which provide a similar functionality to MTRRs. For | |
1679 | these, the ARRs are used to emulate the MTRRs. | |
1680 | The AMD K6-2 (stepping 8 and above) and K6-3 processors have two | |
1681 | MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing | |
1682 | write-combining. All of these processors are supported by this code | |
1683 | and it makes sense to say Y here if you have one of them. | |
1684 | ||
1685 | Saying Y here also fixes a problem with buggy SMP BIOSes which only | |
1686 | set the MTRRs for the boot CPU and not for the secondary CPUs. This | |
1687 | can lead to all sorts of problems, so it's good to say Y here. | |
1688 | ||
1689 | You can safely say Y even if your machine doesn't have MTRRs, you'll | |
1690 | just add about 9 KB to your kernel. | |
1691 | ||
ff61f079 | 1692 | See <file:Documentation/arch/x86/mtrr.rst> for more information. |
506f1d07 | 1693 | |
95ffa243 | 1694 | config MTRR_SANITIZER |
2ffb3501 | 1695 | def_bool y |
95ffa243 YL |
1696 | prompt "MTRR cleanup support" |
1697 | depends on MTRR | |
a7f7f624 | 1698 | help |
aba3728c TG |
1699 | Convert MTRR layout from continuous to discrete, so X drivers can |
1700 | add writeback entries. | |
95ffa243 | 1701 | |
aba3728c | 1702 | Can be disabled with disable_mtrr_cleanup on the kernel command line. |
692105b8 | 1703 | The largest mtrr entry size for a continuous block can be set with |
aba3728c | 1704 | mtrr_chunk_size. |
95ffa243 | 1705 | |
2ffb3501 | 1706 | If unsure, say Y. |
95ffa243 YL |
1707 | |
1708 | config MTRR_SANITIZER_ENABLE_DEFAULT | |
f5098d62 YL |
1709 | int "MTRR cleanup enable value (0-1)" |
1710 | range 0 1 | |
1711 | default "0" | |
95ffa243 | 1712 | depends on MTRR_SANITIZER |
a7f7f624 | 1713 | help |
f5098d62 | 1714 | Enable mtrr cleanup default value |
95ffa243 | 1715 | |
12031a62 YL |
1716 | config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT |
1717 | int "MTRR cleanup spare reg num (0-7)" | |
1718 | range 0 7 | |
1719 | default "1" | |
1720 | depends on MTRR_SANITIZER | |
a7f7f624 | 1721 | help |
12031a62 | 1722 | mtrr cleanup spare entries default, it can be changed via |
aba3728c | 1723 | mtrr_spare_reg_nr=N on the kernel command line. |
12031a62 | 1724 | |
2e5d9c85 | 1725 | config X86_PAT |
6fc108a0 | 1726 | def_bool y |
6a108a14 | 1727 | prompt "x86 PAT support" if EXPERT |
2a8a2719 | 1728 | depends on MTRR |
7a87225a | 1729 | select ARCH_USES_PG_ARCH_2 |
a7f7f624 | 1730 | help |
2e5d9c85 | 1731 | Use PAT attributes to setup page level cache control. |
042b78e4 | 1732 | |
2e5d9c85 | 1733 | PATs are the modern equivalents of MTRRs and are much more |
1734 | flexible than MTRRs. | |
1735 | ||
1736 | Say N here if you see bootup problems (boot crash, boot hang, | |
042b78e4 | 1737 | spontaneous reboots) or a non-working video driver. |
2e5d9c85 | 1738 | |
1739 | If unsure, say Y. | |
1740 | ||
b971880f | 1741 | config X86_UMIP |
796ebc81 | 1742 | def_bool y |
b971880f | 1743 | prompt "User Mode Instruction Prevention" if EXPERT |
a7f7f624 | 1744 | help |
b971880f BM |
1745 | User Mode Instruction Prevention (UMIP) is a security feature in |
1746 | some x86 processors. If enabled, a general protection fault is | |
1747 | issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are | |
1748 | executed in user mode. These instructions unnecessarily expose | |
1749 | information about the hardware state. | |
796ebc81 RN |
1750 | |
1751 | The vast majority of applications do not use these instructions. | |
1752 | For the very few that do, software emulation is provided in | |
1753 | specific cases in protected and virtual-8086 modes. Emulated | |
1754 | results are dummy. | |
aa35f896 | 1755 | |
156ff4a5 PZ |
1756 | config CC_HAS_IBT |
1757 | # GCC >= 9 and binutils >= 2.29 | |
1758 | # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 | |
1759 | # Clang/LLVM >= 14 | |
262448f3 NC |
1760 | # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f |
1761 | # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 | |
156ff4a5 | 1762 | def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ |
262448f3 | 1763 | (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ |
156ff4a5 PZ |
1764 | $(as-instr,endbr64) |
1765 | ||
18e66b69 RE |
1766 | config X86_CET |
1767 | def_bool n | |
1768 | help | |
1769 | CET features configured (Shadow stack or IBT) | |
1770 | ||
156ff4a5 PZ |
1771 | config X86_KERNEL_IBT |
1772 | prompt "Indirect Branch Tracking" | |
4fd5f70c | 1773 | def_bool y |
03f16cd0 | 1774 | depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL |
f6a2c2b2 NC |
1775 | # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f |
1776 | depends on !LD_IS_LLD || LLD_VERSION >= 140000 | |
03f16cd0 | 1777 | select OBJTOOL |
18e66b69 | 1778 | select X86_CET |
156ff4a5 PZ |
1779 | help |
1780 | Build the kernel with support for Indirect Branch Tracking, a | |
1781 | hardware support course-grain forward-edge Control Flow Integrity | |
1782 | protection. It enforces that all indirect calls must land on | |
1783 | an ENDBR instruction, as such, the compiler will instrument the | |
1784 | code with them to make this happen. | |
1785 | ||
ed53a0d9 | 1786 | In addition to building the kernel with IBT, seal all functions that |
4cdfc11b | 1787 | are not indirect call targets, avoiding them ever becoming one. |
ed53a0d9 PZ |
1788 | |
1789 | This requires LTO like objtool runs and will slow down the build. It | |
1790 | does significantly reduce the number of ENDBR instructions in the | |
1791 | kernel image. | |
1792 | ||
35e97790 | 1793 | config X86_INTEL_MEMORY_PROTECTION_KEYS |
38f3e775 | 1794 | prompt "Memory Protection Keys" |
35e97790 | 1795 | def_bool y |
284244a9 | 1796 | # Note: only available in 64-bit mode |
38f3e775 | 1797 | depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) |
52c8e601 IM |
1798 | select ARCH_USES_HIGH_VMA_FLAGS |
1799 | select ARCH_HAS_PKEYS | |
a7f7f624 | 1800 | help |
284244a9 DH |
1801 | Memory Protection Keys provides a mechanism for enforcing |
1802 | page-based protections, but without requiring modification of the | |
1803 | page tables when an application changes protection domains. | |
1804 | ||
1eecbcdc | 1805 | For details, see Documentation/core-api/protection-keys.rst |
284244a9 DH |
1806 | |
1807 | If unsure, say y. | |
35e97790 | 1808 | |
5626f8d4 JG |
1809 | config ARCH_PKEY_BITS |
1810 | int | |
1811 | default 4 | |
1812 | ||
db616173 MH |
1813 | choice |
1814 | prompt "TSX enable mode" | |
1815 | depends on CPU_SUP_INTEL | |
1816 | default X86_INTEL_TSX_MODE_OFF | |
1817 | help | |
1818 | Intel's TSX (Transactional Synchronization Extensions) feature | |
1819 | allows to optimize locking protocols through lock elision which | |
1820 | can lead to a noticeable performance boost. | |
1821 | ||
1822 | On the other hand it has been shown that TSX can be exploited | |
1823 | to form side channel attacks (e.g. TAA) and chances are there | |
1824 | will be more of those attacks discovered in the future. | |
1825 | ||
1826 | Therefore TSX is not enabled by default (aka tsx=off). An admin | |
1827 | might override this decision by tsx=on the command line parameter. | |
1828 | Even with TSX enabled, the kernel will attempt to enable the best | |
1829 | possible TAA mitigation setting depending on the microcode available | |
1830 | for the particular machine. | |
1831 | ||
1832 | This option allows to set the default tsx mode between tsx=on, =off | |
1833 | and =auto. See Documentation/admin-guide/kernel-parameters.txt for more | |
1834 | details. | |
1835 | ||
1836 | Say off if not sure, auto if TSX is in use but it should be used on safe | |
1837 | platforms or on if TSX is in use and the security aspect of tsx is not | |
1838 | relevant. | |
1839 | ||
1840 | config X86_INTEL_TSX_MODE_OFF | |
1841 | bool "off" | |
1842 | help | |
1843 | TSX is disabled if possible - equals to tsx=off command line parameter. | |
1844 | ||
1845 | config X86_INTEL_TSX_MODE_ON | |
1846 | bool "on" | |
1847 | help | |
1848 | TSX is always enabled on TSX capable HW - equals the tsx=on command | |
1849 | line parameter. | |
1850 | ||
1851 | config X86_INTEL_TSX_MODE_AUTO | |
1852 | bool "auto" | |
1853 | help | |
1854 | TSX is enabled on TSX capable HW that is believed to be safe against | |
1855 | side channel attacks- equals the tsx=auto command line parameter. | |
1856 | endchoice | |
1857 | ||
e7e05452 SC |
1858 | config X86_SGX |
1859 | bool "Software Guard eXtensions (SGX)" | |
b8d1d163 | 1860 | depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC |
e59236b5 | 1861 | select CRYPTO_LIB_SHA256 |
e7e05452 | 1862 | select MMU_NOTIFIER |
901ddbb9 | 1863 | select NUMA_KEEP_MEMINFO if NUMA |
40e0e784 | 1864 | select XARRAY_MULTI |
e7e05452 SC |
1865 | help |
1866 | Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions | |
1867 | that can be used by applications to set aside private regions of code | |
1868 | and data, referred to as enclaves. An enclave's private memory can | |
1869 | only be accessed by code running within the enclave. Accesses from | |
1870 | outside the enclave, including other enclaves, are disallowed by | |
1871 | hardware. | |
1872 | ||
1873 | If unsure, say N. | |
1874 | ||
18e66b69 RE |
1875 | config X86_USER_SHADOW_STACK |
1876 | bool "X86 userspace shadow stack" | |
1877 | depends on AS_WRUSS | |
1878 | depends on X86_64 | |
1879 | select ARCH_USES_HIGH_VMA_FLAGS | |
bcc9d04e | 1880 | select ARCH_HAS_USER_SHADOW_STACK |
18e66b69 RE |
1881 | select X86_CET |
1882 | help | |
1883 | Shadow stack protection is a hardware feature that detects function | |
1884 | return address corruption. This helps mitigate ROP attacks. | |
1885 | Applications must be enabled to use it, and old userspace does not | |
1886 | get protection "for free". | |
1887 | ||
1888 | CPUs supporting shadow stacks were first released in 2020. | |
1889 | ||
54acee60 | 1890 | See Documentation/arch/x86/shstk.rst for more information. |
18e66b69 RE |
1891 | |
1892 | If unsure, say N. | |
1893 | ||
c33621b4 KH |
1894 | config INTEL_TDX_HOST |
1895 | bool "Intel Trust Domain Extensions (TDX) host support" | |
1896 | depends on CPU_SUP_INTEL | |
1897 | depends on X86_64 | |
1898 | depends on KVM_INTEL | |
3115cabd | 1899 | depends on X86_X2APIC |
abe8dbab | 1900 | select ARCH_KEEP_MEMBLOCK |
ac3a2208 | 1901 | depends on CONTIG_ALLOC |
cb8eb06d | 1902 | depends on !KEXEC_CORE |
83e1bdc9 | 1903 | depends on X86_MCE |
c33621b4 KH |
1904 | help |
1905 | Intel Trust Domain Extensions (TDX) protects guest VMs from malicious | |
1906 | host and certain physical attacks. This option enables necessary TDX | |
1907 | support in the host kernel to run confidential VMs. | |
1908 | ||
1909 | If unsure, say N. | |
1910 | ||
506f1d07 | 1911 | config EFI |
9ba16087 | 1912 | bool "EFI runtime service support" |
5b83683f | 1913 | depends on ACPI |
f6ce5002 | 1914 | select UCS2_STRING |
022ee6c5 | 1915 | select EFI_RUNTIME_WRAPPERS |
1ff2fc02 | 1916 | select ARCH_USE_MEMREMAP_PROT |
aba7e066 | 1917 | select EFI_RUNTIME_MAP if KEXEC_CORE |
a7f7f624 | 1918 | help |
8f9ca475 IM |
1919 | This enables the kernel to use EFI runtime services that are |
1920 | available (such as the EFI variable services). | |
506f1d07 | 1921 | |
8f9ca475 IM |
1922 | This option is only useful on systems that have EFI firmware. |
1923 | In addition, you should use the latest ELILO loader available | |
1924 | at <http://elilo.sourceforge.net> in order to take advantage | |
1925 | of EFI runtime services. However, even with this option, the | |
1926 | resultant kernel should continue to boot on existing non-EFI | |
1927 | platforms. | |
506f1d07 | 1928 | |
291f3632 | 1929 | config EFI_STUB |
8f24f8c2 | 1930 | bool "EFI stub support" |
c6dbd3e5 | 1931 | depends on EFI |
8f24f8c2 | 1932 | select RELOCATABLE |
a7f7f624 | 1933 | help |
8f24f8c2 | 1934 | This kernel feature allows a bzImage to be loaded directly |
291f3632 MF |
1935 | by EFI firmware without the use of a bootloader. |
1936 | ||
4f4cfa6c | 1937 | See Documentation/admin-guide/efi-stub.rst for more information. |
0c759662 | 1938 | |
cc3fdda2 AB |
1939 | config EFI_HANDOVER_PROTOCOL |
1940 | bool "EFI handover protocol (DEPRECATED)" | |
1941 | depends on EFI_STUB | |
1942 | default y | |
1943 | help | |
1944 | Select this in order to include support for the deprecated EFI | |
1945 | handover protocol, which defines alternative entry points into the | |
1946 | EFI stub. This is a practice that has no basis in the UEFI | |
1947 | specification, and requires a priori knowledge on the part of the | |
1948 | bootloader about Linux/x86 specific ways of passing the command line | |
1949 | and initrd, and where in memory those assets may be loaded. | |
1950 | ||
1951 | If in doubt, say Y. Even though the corresponding support is not | |
1952 | present in upstream GRUB or other bootloaders, most distros build | |
1953 | GRUB with numerous downstream patches applied, and may rely on the | |
1954 | handover protocol as as result. | |
1955 | ||
7d453eee MF |
1956 | config EFI_MIXED |
1957 | bool "EFI mixed-mode support" | |
1958 | depends on EFI_STUB && X86_64 | |
a7f7f624 | 1959 | help |
758cd94a JH |
1960 | Enabling this feature allows a 64-bit kernel to be booted |
1961 | on a 32-bit firmware, provided that your CPU supports 64-bit | |
1962 | mode. | |
7d453eee | 1963 | |
758cd94a JH |
1964 | Note that it is not possible to boot a mixed-mode enabled |
1965 | kernel via the EFI boot stub - a bootloader that supports | |
1966 | the EFI handover protocol must be used. | |
7d453eee | 1967 | |
758cd94a | 1968 | If unsure, say N. |
7d453eee | 1969 | |
1fff234d AB |
1970 | config EFI_RUNTIME_MAP |
1971 | bool "Export EFI runtime maps to sysfs" if EXPERT | |
1972 | depends on EFI | |
1fff234d AB |
1973 | help |
1974 | Export EFI runtime memory regions to /sys/firmware/efi/runtime-map. | |
1975 | That memory map is required by the 2nd kernel to set up EFI virtual | |
1976 | mappings after kexec, but can also be used for debugging purposes. | |
1977 | ||
1978 | See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map. | |
1979 | ||
8636a1f9 | 1980 | source "kernel/Kconfig.hz" |
506f1d07 | 1981 | |
6af51380 ED |
1982 | config ARCH_SUPPORTS_KEXEC |
1983 | def_bool y | |
74ca317c | 1984 | |
6af51380 | 1985 | config ARCH_SUPPORTS_KEXEC_FILE |
c1ad12ee | 1986 | def_bool X86_64 |
b799a09f | 1987 | |
6af51380 ED |
1988 | config ARCH_SELECTS_KEXEC_FILE |
1989 | def_bool y | |
74ca317c | 1990 | depends on KEXEC_FILE |
6af51380 | 1991 | select HAVE_IMA_KEXEC if IMA |
d8eb8940 | 1992 | |
e6265fe7 | 1993 | config ARCH_SUPPORTS_KEXEC_PURGATORY |
c1ad12ee | 1994 | def_bool y |
99d5cadf | 1995 | |
6af51380 ED |
1996 | config ARCH_SUPPORTS_KEXEC_SIG |
1997 | def_bool y | |
8e7d8381 | 1998 | |
6af51380 ED |
1999 | config ARCH_SUPPORTS_KEXEC_SIG_FORCE |
2000 | def_bool y | |
99d5cadf | 2001 | |
6af51380 ED |
2002 | config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG |
2003 | def_bool y | |
8e7d8381 | 2004 | |
6af51380 ED |
2005 | config ARCH_SUPPORTS_KEXEC_JUMP |
2006 | def_bool y | |
506f1d07 | 2007 | |
2b082d6f AG |
2008 | config ARCH_SUPPORTS_KEXEC_HANDOVER |
2009 | def_bool X86_64 | |
2010 | ||
6af51380 ED |
2011 | config ARCH_SUPPORTS_CRASH_DUMP |
2012 | def_bool X86_64 || (X86_32 && HIGHMEM) | |
3ab83521 | 2013 | |
31daa343 DV |
2014 | config ARCH_DEFAULT_CRASH_DUMP |
2015 | def_bool y | |
2016 | ||
ea53ad9c ED |
2017 | config ARCH_SUPPORTS_CRASH_HOTPLUG |
2018 | def_bool y | |
3ab83521 | 2019 | |
9c08a2a1 | 2020 | config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION |
85fcde40 | 2021 | def_bool CRASH_RESERVE |
9c08a2a1 | 2022 | |
506f1d07 | 2023 | config PHYSICAL_START |
6a108a14 | 2024 | hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) |
ceefccc9 | 2025 | default "0x1000000" |
a7f7f624 | 2026 | help |
506f1d07 SR |
2027 | This gives the physical address where the kernel is loaded. |
2028 | ||
43b1d3e6 CK |
2029 | If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage |
2030 | will decompress itself to above physical address and run from there. | |
2031 | Otherwise, bzImage will run from the address where it has been loaded | |
2032 | by the boot loader. The only exception is if it is loaded below the | |
2033 | above physical address, in which case it will relocate itself there. | |
506f1d07 SR |
2034 | |
2035 | In normal kdump cases one does not have to set/change this option | |
2036 | as now bzImage can be compiled as a completely relocatable image | |
2037 | (CONFIG_RELOCATABLE=y) and be used to load and run from a different | |
2038 | address. This option is mainly useful for the folks who don't want | |
2039 | to use a bzImage for capturing the crash dump and want to use a | |
2040 | vmlinux instead. vmlinux is not relocatable hence a kernel needs | |
2041 | to be specifically compiled to run from a specific memory area | |
2042 | (normally a reserved region) and this option comes handy. | |
2043 | ||
ceefccc9 PA |
2044 | So if you are using bzImage for capturing the crash dump, |
2045 | leave the value here unchanged to 0x1000000 and set | |
2046 | CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux | |
2047 | for capturing the crash dump change this value to start of | |
2048 | the reserved region. In other words, it can be set based on | |
2049 | the "X" value as specified in the "crashkernel=YM@XM" | |
2050 | command line boot parameter passed to the panic-ed | |
330d4810 | 2051 | kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst |
ceefccc9 | 2052 | for more details about crash dumps. |
506f1d07 SR |
2053 | |
2054 | Usage of bzImage for capturing the crash dump is recommended as | |
2055 | one does not have to build two kernels. Same kernel can be used | |
2056 | as production kernel and capture kernel. Above option should have | |
2057 | gone away after relocatable bzImage support is introduced. But it | |
2058 | is present because there are users out there who continue to use | |
2059 | vmlinux for dump capture. This option should go away down the | |
2060 | line. | |
2061 | ||
2062 | Don't change this unless you know what you are doing. | |
2063 | ||
2064 | config RELOCATABLE | |
26717808 PA |
2065 | bool "Build a relocatable kernel" |
2066 | default y | |
a7f7f624 | 2067 | help |
506f1d07 SR |
2068 | This builds a kernel image that retains relocation information |
2069 | so it can be loaded someplace besides the default 1MB. | |
2070 | The relocations tend to make the kernel binary about 10% larger, | |
2071 | but are discarded at runtime. | |
2072 | ||
2073 | One use is for the kexec on panic case where the recovery kernel | |
2074 | must live at a different physical address than the primary | |
2075 | kernel. | |
2076 | ||
2077 | Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address | |
2078 | it has been loaded at and the compile time physical address | |
8ab3820f | 2079 | (CONFIG_PHYSICAL_START) is used as the minimum location. |
506f1d07 | 2080 | |
8ab3820f | 2081 | config RANDOMIZE_BASE |
e8581e3d | 2082 | bool "Randomize the address of the kernel image (KASLR)" |
8ab3820f | 2083 | depends on RELOCATABLE |
6807c846 | 2084 | default y |
a7f7f624 | 2085 | help |
e8581e3d BH |
2086 | In support of Kernel Address Space Layout Randomization (KASLR), |
2087 | this randomizes the physical address at which the kernel image | |
2088 | is decompressed and the virtual address where the kernel | |
2089 | image is mapped, as a security feature that deters exploit | |
2090 | attempts relying on knowledge of the location of kernel | |
2091 | code internals. | |
2092 | ||
ed9f007e KC |
2093 | On 64-bit, the kernel physical and virtual addresses are |
2094 | randomized separately. The physical address will be anywhere | |
2095 | between 16MB and the top of physical memory (up to 64TB). The | |
2096 | virtual address will be randomized from 16MB up to 1GB (9 bits | |
2097 | of entropy). Note that this also reduces the memory space | |
2098 | available to kernel modules from 1.5GB to 1GB. | |
2099 | ||
2100 | On 32-bit, the kernel physical and virtual addresses are | |
2101 | randomized together. They will be randomized from 16MB up to | |
2102 | 512MB (8 bits of entropy). | |
e8581e3d BH |
2103 | |
2104 | Entropy is generated using the RDRAND instruction if it is | |
2105 | supported. If RDTSC is supported, its value is mixed into | |
2106 | the entropy pool as well. If neither RDRAND nor RDTSC are | |
ed9f007e KC |
2107 | supported, then entropy is read from the i8254 timer. The |
2108 | usable entropy is limited by the kernel being built using | |
2109 | 2GB addressing, and that PHYSICAL_ALIGN must be at a | |
2110 | minimum of 2MB. As a result, only 10 bits of entropy are | |
2111 | theoretically possible, but the implementations are further | |
2112 | limited due to memory layouts. | |
e8581e3d | 2113 | |
6807c846 | 2114 | If unsure, say Y. |
8ab3820f KC |
2115 | |
2116 | # Relocation on x86 needs some additional build support | |
845adf72 PA |
2117 | config X86_NEED_RELOCS |
2118 | def_bool y | |
8ab3820f | 2119 | depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) |
9b400d17 | 2120 | select ARCH_VMLINUX_NEEDS_RELOCS |
845adf72 | 2121 | |
506f1d07 | 2122 | config PHYSICAL_ALIGN |
a0215061 | 2123 | hex "Alignment value to which kernel should be aligned" |
8ab3820f | 2124 | default "0x200000" |
a0215061 KC |
2125 | range 0x2000 0x1000000 if X86_32 |
2126 | range 0x200000 0x1000000 if X86_64 | |
a7f7f624 | 2127 | help |
506f1d07 SR |
2128 | This value puts the alignment restrictions on physical address |
2129 | where kernel is loaded and run from. Kernel is compiled for an | |
2130 | address which meets above alignment restriction. | |
2131 | ||
2132 | If bootloader loads the kernel at a non-aligned address and | |
2133 | CONFIG_RELOCATABLE is set, kernel will move itself to nearest | |
2134 | address aligned to above value and run from there. | |
2135 | ||
2136 | If bootloader loads the kernel at a non-aligned address and | |
2137 | CONFIG_RELOCATABLE is not set, kernel will ignore the run time | |
2138 | load address and decompress itself to the address it has been | |
2139 | compiled for and run from there. The address for which kernel is | |
2140 | compiled already meets above alignment restrictions. Hence the | |
2141 | end result is that kernel runs from a physical address meeting | |
2142 | above alignment restrictions. | |
2143 | ||
a0215061 KC |
2144 | On 32-bit this value must be a multiple of 0x2000. On 64-bit |
2145 | this value must be a multiple of 0x200000. | |
2146 | ||
506f1d07 SR |
2147 | Don't change this unless you know what you are doing. |
2148 | ||
0483e1fa TG |
2149 | config RANDOMIZE_MEMORY |
2150 | bool "Randomize the kernel memory sections" | |
2151 | depends on X86_64 | |
2152 | depends on RANDOMIZE_BASE | |
2153 | default RANDOMIZE_BASE | |
a7f7f624 | 2154 | help |
758cd94a JH |
2155 | Randomizes the base virtual address of kernel memory sections |
2156 | (physical memory mapping, vmalloc & vmemmap). This security feature | |
2157 | makes exploits relying on predictable memory locations less reliable. | |
0483e1fa | 2158 | |
758cd94a JH |
2159 | The order of allocations remains unchanged. Entropy is generated in |
2160 | the same way as RANDOMIZE_BASE. Current implementation in the optimal | |
2161 | configuration have in average 30,000 different possible virtual | |
2162 | addresses for each memory section. | |
0483e1fa | 2163 | |
758cd94a | 2164 | If unsure, say Y. |
0483e1fa | 2165 | |
90397a41 TG |
2166 | config RANDOMIZE_MEMORY_PHYSICAL_PADDING |
2167 | hex "Physical memory mapping padding" if EXPERT | |
2168 | depends on RANDOMIZE_MEMORY | |
2169 | default "0xa" if MEMORY_HOTPLUG | |
2170 | default "0x0" | |
2171 | range 0x1 0x40 if MEMORY_HOTPLUG | |
2172 | range 0x0 0x40 | |
a7f7f624 | 2173 | help |
758cd94a JH |
2174 | Define the padding in terabytes added to the existing physical |
2175 | memory size during kernel memory randomization. It is useful | |
2176 | for memory hotplug support but reduces the entropy available for | |
2177 | address randomization. | |
90397a41 | 2178 | |
758cd94a | 2179 | If unsure, leave at the default value. |
90397a41 | 2180 | |
6449dcb0 KS |
2181 | config ADDRESS_MASKING |
2182 | bool "Linear Address Masking support" | |
2183 | depends on X86_64 | |
3267cb6d | 2184 | depends on COMPILE_TEST || !CPU_MITIGATIONS # wait for LASS |
6449dcb0 KS |
2185 | help |
2186 | Linear Address Masking (LAM) modifies the checking that is applied | |
2187 | to 64-bit linear addresses, allowing software to use of the | |
2188 | untranslated address bits for metadata. | |
2189 | ||
2190 | The capability can be used for efficient address sanitizers (ASAN) | |
2191 | implementation and for optimizations in JITs. | |
2192 | ||
506f1d07 | 2193 | config HOTPLUG_CPU |
bebd024e | 2194 | def_bool y |
40b31360 | 2195 | depends on SMP |
506f1d07 SR |
2196 | |
2197 | config COMPAT_VDSO | |
b0b49f26 | 2198 | def_bool n |
de711563 | 2199 | prompt "Workaround for glibc 2.3.2 / 2.3.3 (released in year 2003/2004)" |
953fee1d | 2200 | depends on COMPAT_32 |
a7f7f624 | 2201 | help |
b0b49f26 AL |
2202 | Certain buggy versions of glibc will crash if they are |
2203 | presented with a 32-bit vDSO that is not mapped at the address | |
2204 | indicated in its segment table. | |
e84446de | 2205 | |
b0b49f26 AL |
2206 | The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a |
2207 | and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and | |
2208 | 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is | |
2209 | the only released version with the bug, but OpenSUSE 9 | |
2210 | contains a buggy "glibc 2.3.2". | |
506f1d07 | 2211 | |
b0b49f26 AL |
2212 | The symptom of the bug is that everything crashes on startup, saying: |
2213 | dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! | |
2214 | ||
2215 | Saying Y here changes the default value of the vdso32 boot | |
2216 | option from 1 to 0, which turns off the 32-bit vDSO entirely. | |
2217 | This works around the glibc bug but hurts performance. | |
2218 | ||
2219 | If unsure, say N: if you are compiling your own kernel, you | |
2220 | are unlikely to be using a buggy version of glibc. | |
506f1d07 | 2221 | |
3dc33bd3 KC |
2222 | choice |
2223 | prompt "vsyscall table for legacy applications" | |
2224 | depends on X86_64 | |
625b7b7f | 2225 | default LEGACY_VSYSCALL_XONLY |
3dc33bd3 KC |
2226 | help |
2227 | Legacy user code that does not know how to find the vDSO expects | |
2228 | to be able to issue three syscalls by calling fixed addresses in | |
2229 | kernel space. Since this location is not randomized with ASLR, | |
2230 | it can be used to assist security vulnerability exploitation. | |
2231 | ||
2232 | This setting can be changed at boot time via the kernel command | |
bf00745e AL |
2233 | line parameter vsyscall=[emulate|xonly|none]. Emulate mode |
2234 | is deprecated and can only be enabled using the kernel command | |
2235 | line. | |
3dc33bd3 KC |
2236 | |
2237 | On a system with recent enough glibc (2.14 or newer) and no | |
2238 | static binaries, you can say None without a performance penalty | |
2239 | to improve security. | |
2240 | ||
bd49e16e | 2241 | If unsure, select "Emulate execution only". |
3dc33bd3 | 2242 | |
bd49e16e AL |
2243 | config LEGACY_VSYSCALL_XONLY |
2244 | bool "Emulate execution only" | |
2245 | help | |
2246 | The kernel traps and emulates calls into the fixed vsyscall | |
2247 | address mapping and does not allow reads. This | |
2248 | configuration is recommended when userspace might use the | |
2249 | legacy vsyscall area but support for legacy binary | |
2250 | instrumentation of legacy code is not needed. It mitigates | |
2251 | certain uses of the vsyscall area as an ASLR-bypassing | |
2252 | buffer. | |
3dc33bd3 KC |
2253 | |
2254 | config LEGACY_VSYSCALL_NONE | |
2255 | bool "None" | |
2256 | help | |
2257 | There will be no vsyscall mapping at all. This will | |
2258 | eliminate any risk of ASLR bypass due to the vsyscall | |
2259 | fixed address mapping. Attempts to use the vsyscalls | |
2260 | will be reported to dmesg, so that either old or | |
2261 | malicious userspace programs can be identified. | |
2262 | ||
2263 | endchoice | |
2264 | ||
516cbf37 TB |
2265 | config CMDLINE_BOOL |
2266 | bool "Built-in kernel command line" | |
a7f7f624 | 2267 | help |
516cbf37 TB |
2268 | Allow for specifying boot arguments to the kernel at |
2269 | build time. On some systems (e.g. embedded ones), it is | |
2270 | necessary or convenient to provide some or all of the | |
2271 | kernel boot arguments with the kernel itself (that is, | |
2272 | to not rely on the boot loader to provide them.) | |
2273 | ||
2274 | To compile command line arguments into the kernel, | |
2275 | set this option to 'Y', then fill in the | |
69711ca1 | 2276 | boot arguments in CONFIG_CMDLINE. |
516cbf37 TB |
2277 | |
2278 | Systems with fully functional boot loaders (i.e. non-embedded) | |
2279 | should leave this option set to 'N'. | |
2280 | ||
2281 | config CMDLINE | |
2282 | string "Built-in kernel command string" | |
2283 | depends on CMDLINE_BOOL | |
2284 | default "" | |
a7f7f624 | 2285 | help |
516cbf37 TB |
2286 | Enter arguments here that should be compiled into the kernel |
2287 | image and used at boot time. If the boot loader provides a | |
2288 | command line at boot time, it is appended to this string to | |
2289 | form the full kernel command line, when the system boots. | |
2290 | ||
2291 | However, you can use the CONFIG_CMDLINE_OVERRIDE option to | |
2292 | change this behavior. | |
2293 | ||
2294 | In most cases, the command line (whether built-in or provided | |
2295 | by the boot loader) should specify the device for the root | |
2296 | file system. | |
2297 | ||
2298 | config CMDLINE_OVERRIDE | |
2299 | bool "Built-in command line overrides boot loader arguments" | |
645e6466 | 2300 | depends on CMDLINE_BOOL && CMDLINE != "" |
a7f7f624 | 2301 | help |
516cbf37 TB |
2302 | Set this option to 'Y' to have the kernel ignore the boot loader |
2303 | command line, and use ONLY the built-in command line. | |
2304 | ||
2305 | This is used to work around broken boot loaders. This should | |
2306 | be set to 'N' under normal conditions. | |
2307 | ||
a5b9e5a2 AL |
2308 | config MODIFY_LDT_SYSCALL |
2309 | bool "Enable the LDT (local descriptor table)" if EXPERT | |
2310 | default y | |
a7f7f624 | 2311 | help |
a5b9e5a2 AL |
2312 | Linux can allow user programs to install a per-process x86 |
2313 | Local Descriptor Table (LDT) using the modify_ldt(2) system | |
2314 | call. This is required to run 16-bit or segmented code such as | |
2315 | DOSEMU or some Wine programs. It is also used by some very old | |
2316 | threading libraries. | |
2317 | ||
2318 | Enabling this feature adds a small amount of overhead to | |
2319 | context switches and increases the low-level kernel attack | |
2320 | surface. Disabling it removes the modify_ldt(2) system call. | |
2321 | ||
2322 | Saying 'N' here may make sense for embedded or server kernels. | |
2323 | ||
3aac3ebe TG |
2324 | config STRICT_SIGALTSTACK_SIZE |
2325 | bool "Enforce strict size checking for sigaltstack" | |
2326 | depends on DYNAMIC_SIGFRAME | |
2327 | help | |
2328 | For historical reasons MINSIGSTKSZ is a constant which became | |
2329 | already too small with AVX512 support. Add a mechanism to | |
2330 | enforce strict checking of the sigaltstack size against the | |
2331 | real size of the FPU frame. This option enables the check | |
2332 | by default. It can also be controlled via the kernel command | |
2333 | line option 'strict_sas_size' independent of this config | |
2334 | switch. Enabling it might break existing applications which | |
2335 | allocate a too small sigaltstack but 'work' because they | |
2336 | never get a signal delivered. | |
2337 | ||
2338 | Say 'N' unless you want to really enforce this check. | |
2339 | ||
d6f635bc KC |
2340 | config CFI_AUTO_DEFAULT |
2341 | bool "Attempt to use FineIBT by default at boot time" | |
2342 | depends on FINEIBT | |
5595c31c | 2343 | depends on !RUST || RUSTC_VERSION >= 108800 |
d6f635bc KC |
2344 | default y |
2345 | help | |
2346 | Attempt to use FineIBT by default at boot time. If enabled, | |
2347 | this is the same as booting with "cfi=auto". If disabled, | |
2348 | this is the same as booting with "cfi=kcfi". | |
2349 | ||
b700e7f0 SJ |
2350 | source "kernel/livepatch/Kconfig" |
2351 | ||
350afa8a RB |
2352 | config X86_BUS_LOCK_DETECT |
2353 | bool "Split Lock Detect and Bus Lock Detect support" | |
408eb741 | 2354 | depends on CPU_SUP_INTEL || CPU_SUP_AMD |
350afa8a RB |
2355 | default y |
2356 | help | |
2357 | Enable Split Lock Detect and Bus Lock Detect functionalities. | |
2358 | See <file:Documentation/arch/x86/buslock.rst> for more information. | |
2359 | ||
506f1d07 SR |
2360 | endmenu |
2361 | ||
1ca3683c | 2362 | config CC_HAS_NAMED_AS |
47ff30cc UB |
2363 | def_bool $(success,echo 'int __seg_fs fs; int __seg_gs gs;' | $(CC) -x c - -S -o /dev/null) |
2364 | depends on CC_IS_GCC | |
1ca3683c | 2365 | |
b6762467 UB |
2366 | # |
2367 | # -fsanitize=kernel-address (KASAN) and -fsanitize=thread (KCSAN) | |
2368 | # are incompatible with named address spaces with GCC < 13.3 | |
2369 | # (see GCC PR sanitizer/111736 and also PR sanitizer/115172). | |
2370 | # | |
2371 | ||
9ebe5500 | 2372 | config CC_HAS_NAMED_AS_FIXED_SANITIZERS |
b6762467 UB |
2373 | def_bool y |
2374 | depends on !(KASAN || KCSAN) || GCC_VERSION >= 130300 | |
2375 | depends on !(UBSAN_BOOL && KASAN) || GCC_VERSION >= 140200 | |
1ca3683c UB |
2376 | |
2377 | config USE_X86_SEG_SUPPORT | |
b6762467 UB |
2378 | def_bool CC_HAS_NAMED_AS |
2379 | depends on CC_HAS_NAMED_AS_FIXED_SANITIZERS | |
1ca3683c | 2380 | |
f43b9876 PZ |
2381 | config CC_HAS_SLS |
2382 | def_bool $(cc-option,-mharden-sls=all) | |
2383 | ||
2384 | config CC_HAS_RETURN_THUNK | |
2385 | def_bool $(cc-option,-mfunction-return=thunk-extern) | |
2386 | ||
bea75b33 TG |
2387 | config CC_HAS_ENTRY_PADDING |
2388 | def_bool $(cc-option,-fpatchable-function-entry=16,16) | |
2389 | ||
0c92385d PZ |
2390 | config CC_HAS_KCFI_ARITY |
2391 | def_bool $(cc-option,-fsanitize=kcfi -fsanitize-kcfi-arity) | |
2392 | depends on CC_IS_CLANG && !RUST | |
2393 | ||
bea75b33 TG |
2394 | config FUNCTION_PADDING_CFI |
2395 | int | |
2396 | default 59 if FUNCTION_ALIGNMENT_64B | |
2397 | default 27 if FUNCTION_ALIGNMENT_32B | |
2398 | default 11 if FUNCTION_ALIGNMENT_16B | |
2399 | default 3 if FUNCTION_ALIGNMENT_8B | |
2400 | default 0 | |
2401 | ||
2402 | # Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG | |
2403 | # except Kconfig can't do arithmetic :/ | |
2404 | config FUNCTION_PADDING_BYTES | |
2405 | int | |
2406 | default FUNCTION_PADDING_CFI if CFI_CLANG | |
2407 | default FUNCTION_ALIGNMENT | |
2408 | ||
931ab636 PZ |
2409 | config CALL_PADDING |
2410 | def_bool n | |
2411 | depends on CC_HAS_ENTRY_PADDING && OBJTOOL | |
2412 | select FUNCTION_ALIGNMENT_16B | |
2413 | ||
2414 | config FINEIBT | |
2415 | def_bool y | |
aefb2f2e | 2416 | depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE |
931ab636 PZ |
2417 | select CALL_PADDING |
2418 | ||
0c92385d PZ |
2419 | config FINEIBT_BHI |
2420 | def_bool y | |
2421 | depends on FINEIBT && CC_HAS_KCFI_ARITY | |
2422 | ||
8f7c0d8b TG |
2423 | config HAVE_CALL_THUNKS |
2424 | def_bool y | |
0911b8c5 | 2425 | depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL |
8f7c0d8b TG |
2426 | |
2427 | config CALL_THUNKS | |
2428 | def_bool n | |
931ab636 | 2429 | select CALL_PADDING |
8f7c0d8b | 2430 | |
b341b20d PZ |
2431 | config PREFIX_SYMBOLS |
2432 | def_bool y | |
931ab636 | 2433 | depends on CALL_PADDING && !CFI_CLANG |
b341b20d | 2434 | |
fe42754b SC |
2435 | menuconfig CPU_MITIGATIONS |
2436 | bool "Mitigations for CPU vulnerabilities" | |
f43b9876 PZ |
2437 | default y |
2438 | help | |
fe42754b SC |
2439 | Say Y here to enable options which enable mitigations for hardware |
2440 | vulnerabilities (usually related to speculative execution). | |
ce0abef6 SC |
2441 | Mitigations can be disabled or restricted to SMT systems at runtime |
2442 | via the "mitigations" kernel parameter. | |
f43b9876 | 2443 | |
ce0abef6 SC |
2444 | If you say N, all mitigations will be disabled. This CANNOT be |
2445 | overridden at runtime. | |
2446 | ||
2447 | Say 'Y', unless you really know what you are doing. | |
f43b9876 | 2448 | |
fe42754b | 2449 | if CPU_MITIGATIONS |
f43b9876 | 2450 | |
ea4654e0 | 2451 | config MITIGATION_PAGE_TABLE_ISOLATION |
f43b9876 PZ |
2452 | bool "Remove the kernel mapping in user mode" |
2453 | default y | |
2454 | depends on (X86_64 || X86_PAE) | |
2455 | help | |
2456 | This feature reduces the number of hardware side channels by | |
2457 | ensuring that the majority of kernel addresses are not mapped | |
2458 | into userspace. | |
2459 | ||
ff61f079 | 2460 | See Documentation/arch/x86/pti.rst for more details. |
f43b9876 | 2461 | |
aefb2f2e | 2462 | config MITIGATION_RETPOLINE |
f43b9876 PZ |
2463 | bool "Avoid speculative indirect branches in kernel" |
2464 | select OBJTOOL if HAVE_OBJTOOL | |
2465 | default y | |
2466 | help | |
2467 | Compile kernel with the retpoline compiler options to guard against | |
2468 | kernel-to-user data leaks by avoiding speculative indirect | |
2469 | branches. Requires a compiler with -mindirect-branch=thunk-extern | |
2470 | support for full protection. The kernel may run slower. | |
2471 | ||
0911b8c5 | 2472 | config MITIGATION_RETHUNK |
f43b9876 | 2473 | bool "Enable return-thunks" |
aefb2f2e | 2474 | depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK |
f43b9876 | 2475 | select OBJTOOL if HAVE_OBJTOOL |
b648ab48 | 2476 | default y if X86_64 |
f43b9876 PZ |
2477 | help |
2478 | Compile the kernel with the return-thunks compiler option to guard | |
2479 | against kernel-to-user data leaks by avoiding return speculation. | |
2480 | Requires a compiler with -mfunction-return=thunk-extern | |
2481 | support for full protection. The kernel may run slower. | |
2482 | ||
ac61d439 | 2483 | config MITIGATION_UNRET_ENTRY |
f43b9876 | 2484 | bool "Enable UNRET on kernel entry" |
0911b8c5 | 2485 | depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64 |
f43b9876 PZ |
2486 | default y |
2487 | help | |
2488 | Compile the kernel with support for the retbleed=unret mitigation. | |
2489 | ||
5fa31af3 | 2490 | config MITIGATION_CALL_DEPTH_TRACKING |
80e4c1cd TG |
2491 | bool "Mitigate RSB underflow with call depth tracking" |
2492 | depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS | |
2493 | select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE | |
2494 | select CALL_THUNKS | |
2495 | default y | |
2496 | help | |
2497 | Compile the kernel with call depth tracking to mitigate the Intel | |
86e39b94 BL |
2498 | SKL Return-Stack-Buffer (RSB) underflow issue. The mitigation is off |
2499 | by default and needs to be enabled on the kernel command line via the | |
2500 | retbleed=stuff option. For non-affected systems the overhead of this | |
2501 | option is marginal as the call depth tracking is using run-time | |
2502 | generated call thunks in a compiler generated padding area and call | |
2503 | patching. This increases text size by ~5%. For non affected systems | |
2504 | this space is unused. On affected SKL systems this results in a | |
2505 | significant performance gain over the IBRS mitigation. | |
80e4c1cd | 2506 | |
e81dc127 TG |
2507 | config CALL_THUNKS_DEBUG |
2508 | bool "Enable call thunks and call depth tracking debugging" | |
5fa31af3 | 2509 | depends on MITIGATION_CALL_DEPTH_TRACKING |
e81dc127 TG |
2510 | select FUNCTION_ALIGNMENT_32B |
2511 | default n | |
2512 | help | |
2513 | Enable call/ret counters for imbalance detection and build in | |
2514 | a noisy dmesg about callthunks generation and call patching for | |
2515 | trouble shooting. The debug prints need to be enabled on the | |
2516 | kernel command line with 'debug-callthunks'. | |
54628de6 RD |
2517 | Only enable this when you are debugging call thunks as this |
2518 | creates a noticeable runtime overhead. If unsure say N. | |
80e4c1cd | 2519 | |
e0b8fcfa | 2520 | config MITIGATION_IBPB_ENTRY |
f43b9876 | 2521 | bool "Enable IBPB on kernel entry" |
b648ab48 | 2522 | depends on CPU_SUP_AMD && X86_64 |
f43b9876 PZ |
2523 | default y |
2524 | help | |
318e8c33 PB |
2525 | Compile the kernel with support for the retbleed=ibpb and |
2526 | spec_rstack_overflow={ibpb,ibpb-vmexit} mitigations. | |
f43b9876 | 2527 | |
1da8d217 | 2528 | config MITIGATION_IBRS_ENTRY |
f43b9876 | 2529 | bool "Enable IBRS on kernel entry" |
b648ab48 | 2530 | depends on CPU_SUP_INTEL && X86_64 |
f43b9876 PZ |
2531 | default y |
2532 | help | |
2533 | Compile the kernel with support for the spectre_v2=ibrs mitigation. | |
2534 | This mitigates both spectre_v2 and retbleed at great cost to | |
2535 | performance. | |
2536 | ||
a033eec9 | 2537 | config MITIGATION_SRSO |
fb3bd914 | 2538 | bool "Mitigate speculative RAS overflow on AMD" |
0911b8c5 | 2539 | depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK |
fb3bd914 BPA |
2540 | default y |
2541 | help | |
2542 | Enable the SRSO mitigation needed on AMD Zen1-4 machines. | |
2543 | ||
7b75782f | 2544 | config MITIGATION_SLS |
f43b9876 PZ |
2545 | bool "Mitigate Straight-Line-Speculation" |
2546 | depends on CC_HAS_SLS && X86_64 | |
2547 | select OBJTOOL if HAVE_OBJTOOL | |
2548 | default n | |
2549 | help | |
2550 | Compile the kernel with straight-line-speculation options to guard | |
2551 | against straight line speculation. The kernel image might be slightly | |
2552 | larger. | |
2553 | ||
225f2bd0 BL |
2554 | config MITIGATION_GDS |
2555 | bool "Mitigate Gather Data Sampling" | |
2556 | depends on CPU_SUP_INTEL | |
2557 | default y | |
2558 | help | |
2559 | Enable mitigation for Gather Data Sampling (GDS). GDS is a hardware | |
2560 | vulnerability which allows unprivileged speculative access to data | |
2561 | which was previously stored in vector registers. The attacker uses gather | |
2562 | instructions to infer the stale vector register data. | |
2563 | ||
8076fcde PG |
2564 | config MITIGATION_RFDS |
2565 | bool "RFDS Mitigation" | |
2566 | depends on CPU_SUP_INTEL | |
2567 | default y | |
2568 | help | |
2569 | Enable mitigation for Register File Data Sampling (RFDS) by default. | |
2570 | RFDS is a hardware vulnerability which affects Intel Atom CPUs. It | |
2571 | allows unprivileged speculative access to stale data previously | |
2572 | stored in floating point, vector and integer registers. | |
2573 | See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst> | |
2574 | ||
4f511739 JP |
2575 | config MITIGATION_SPECTRE_BHI |
2576 | bool "Mitigate Spectre-BHB (Branch History Injection)" | |
ec9404e4 | 2577 | depends on CPU_SUP_INTEL |
4f511739 | 2578 | default y |
ec9404e4 PG |
2579 | help |
2580 | Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks | |
2581 | where the branch history buffer is poisoned to speculatively steer | |
2582 | indirect branches. | |
2583 | See <file:Documentation/admin-guide/hw-vuln/spectre.rst> | |
2584 | ||
94045568 BL |
2585 | config MITIGATION_MDS |
2586 | bool "Mitigate Microarchitectural Data Sampling (MDS) hardware bug" | |
2587 | depends on CPU_SUP_INTEL | |
2588 | default y | |
2589 | help | |
2590 | Enable mitigation for Microarchitectural Data Sampling (MDS). MDS is | |
2591 | a hardware vulnerability which allows unprivileged speculative access | |
2592 | to data which is available in various CPU internal buffers. | |
2593 | See also <file:Documentation/admin-guide/hw-vuln/mds.rst> | |
b8da0b33 BL |
2594 | |
2595 | config MITIGATION_TAA | |
2596 | bool "Mitigate TSX Asynchronous Abort (TAA) hardware bug" | |
2597 | depends on CPU_SUP_INTEL | |
2598 | default y | |
2599 | help | |
2600 | Enable mitigation for TSX Asynchronous Abort (TAA). TAA is a hardware | |
2601 | vulnerability that allows unprivileged speculative access to data | |
2602 | which is available in various CPU internal buffers by using | |
2603 | asynchronous aborts within an Intel TSX transactional region. | |
2604 | See also <file:Documentation/admin-guide/hw-vuln/tsx_async_abort.rst> | |
163f9fe6 BL |
2605 | |
2606 | config MITIGATION_MMIO_STALE_DATA | |
2607 | bool "Mitigate MMIO Stale Data hardware bug" | |
2608 | depends on CPU_SUP_INTEL | |
2609 | default y | |
2610 | help | |
2611 | Enable mitigation for MMIO Stale Data hardware bugs. Processor MMIO | |
2612 | Stale Data Vulnerabilities are a class of memory-mapped I/O (MMIO) | |
2613 | vulnerabilities that can expose data. The vulnerabilities require the | |
2614 | attacker to have access to MMIO. | |
2615 | See also | |
2616 | <file:Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst> | |
3a4ee4ff BL |
2617 | |
2618 | config MITIGATION_L1TF | |
2619 | bool "Mitigate L1 Terminal Fault (L1TF) hardware bug" | |
2620 | depends on CPU_SUP_INTEL | |
2621 | default y | |
2622 | help | |
2623 | Mitigate L1 Terminal Fault (L1TF) hardware bug. L1 Terminal Fault is a | |
2624 | hardware vulnerability which allows unprivileged speculative access to data | |
2625 | available in the Level 1 Data Cache. | |
2626 | See <file:Documentation/admin-guide/hw-vuln/l1tf.rst | |
894e2885 BL |
2627 | |
2628 | config MITIGATION_RETBLEED | |
2629 | bool "Mitigate RETBleed hardware bug" | |
2630 | depends on (CPU_SUP_INTEL && MITIGATION_SPECTRE_V2) || MITIGATION_UNRET_ENTRY || MITIGATION_IBPB_ENTRY | |
2631 | default y | |
2632 | help | |
2633 | Enable mitigation for RETBleed (Arbitrary Speculative Code Execution | |
2634 | with Return Instructions) vulnerability. RETBleed is a speculative | |
2635 | execution attack which takes advantage of microarchitectural behavior | |
2636 | in many modern microprocessors, similar to Spectre v2. An | |
2637 | unprivileged attacker can use these flaws to bypass conventional | |
2638 | memory security restrictions to gain read access to privileged memory | |
2639 | that would otherwise be inaccessible. | |
ca01c0d8 BL |
2640 | |
2641 | config MITIGATION_SPECTRE_V1 | |
2642 | bool "Mitigate SPECTRE V1 hardware bug" | |
2643 | default y | |
2644 | help | |
2645 | Enable mitigation for Spectre V1 (Bounds Check Bypass). Spectre V1 is a | |
2646 | class of side channel attacks that takes advantage of speculative | |
2647 | execution that bypasses conditional branch instructions used for | |
2648 | memory access bounds check. | |
2649 | See also <file:Documentation/admin-guide/hw-vuln/spectre.rst> | |
a0b02e3f | 2650 | |
72c70f48 BL |
2651 | config MITIGATION_SPECTRE_V2 |
2652 | bool "Mitigate SPECTRE V2 hardware bug" | |
2653 | default y | |
2654 | help | |
2655 | Enable mitigation for Spectre V2 (Branch Target Injection). Spectre | |
2656 | V2 is a class of side channel attacks that takes advantage of | |
2657 | indirect branch predictors inside the processor. In Spectre variant 2 | |
2658 | attacks, the attacker can steer speculative indirect branches in the | |
2659 | victim to gadget code by poisoning the branch target buffer of a CPU | |
2660 | used for predicting indirect branch addresses. | |
2661 | See also <file:Documentation/admin-guide/hw-vuln/spectre.rst> | |
2662 | ||
a0b02e3f BL |
2663 | config MITIGATION_SRBDS |
2664 | bool "Mitigate Special Register Buffer Data Sampling (SRBDS) hardware bug" | |
2665 | depends on CPU_SUP_INTEL | |
2666 | default y | |
2667 | help | |
2668 | Enable mitigation for Special Register Buffer Data Sampling (SRBDS). | |
2669 | SRBDS is a hardware vulnerability that allows Microarchitectural Data | |
2670 | Sampling (MDS) techniques to infer values returned from special | |
2671 | register accesses. An unprivileged user can extract values returned | |
2672 | from RDRAND and RDSEED executed on another core or sibling thread | |
2673 | using MDS techniques. | |
2674 | See also | |
2675 | <file:Documentation/admin-guide/hw-vuln/special-register-buffer-data-sampling.rst> | |
b908cdab BL |
2676 | |
2677 | config MITIGATION_SSB | |
2678 | bool "Mitigate Speculative Store Bypass (SSB) hardware bug" | |
2679 | default y | |
2680 | help | |
2681 | Enable mitigation for Speculative Store Bypass (SSB). SSB is a | |
2682 | hardware security vulnerability and its exploitation takes advantage | |
2683 | of speculative execution in a similar way to the Meltdown and Spectre | |
2684 | security vulnerabilities. | |
2685 | ||
8754e67a PG |
2686 | config MITIGATION_ITS |
2687 | bool "Enable Indirect Target Selection mitigation" | |
2688 | depends on CPU_SUP_INTEL && X86_64 | |
2689 | depends on MITIGATION_RETPOLINE && MITIGATION_RETHUNK | |
872df34d | 2690 | select EXECMEM |
8754e67a PG |
2691 | default y |
2692 | help | |
2693 | Enable Indirect Target Selection (ITS) mitigation. ITS is a bug in | |
2694 | BPU on some Intel CPUs that may allow Spectre V2 style attacks. If | |
2695 | disabled, mitigation cannot be enabled via cmdline. | |
2696 | See <file:Documentation/admin-guide/hw-vuln/indirect-target-selection.rst> | |
2697 | ||
f43b9876 PZ |
2698 | endif |
2699 | ||
3072e413 MH |
2700 | config ARCH_HAS_ADD_PAGES |
2701 | def_bool y | |
5c11f00b | 2702 | depends on ARCH_ENABLE_MEMORY_HOTPLUG |
3072e413 | 2703 | |
da85f865 | 2704 | menu "Power management and ACPI options" |
e279b6c1 SR |
2705 | |
2706 | config ARCH_HIBERNATION_HEADER | |
3c2362e6 | 2707 | def_bool y |
44556530 | 2708 | depends on HIBERNATION |
e279b6c1 SR |
2709 | |
2710 | source "kernel/power/Kconfig" | |
2711 | ||
2712 | source "drivers/acpi/Kconfig" | |
2713 | ||
a6b68076 | 2714 | config X86_APM_BOOT |
6fc108a0 | 2715 | def_bool y |
282e5aab | 2716 | depends on APM |
a6b68076 | 2717 | |
e279b6c1 SR |
2718 | menuconfig APM |
2719 | tristate "APM (Advanced Power Management) BIOS support" | |
efefa6f6 | 2720 | depends on X86_32 && PM_SLEEP |
a7f7f624 | 2721 | help |
e279b6c1 SR |
2722 | APM is a BIOS specification for saving power using several different |
2723 | techniques. This is mostly useful for battery powered laptops with | |
2724 | APM compliant BIOSes. If you say Y here, the system time will be | |
2725 | reset after a RESUME operation, the /proc/apm device will provide | |
2726 | battery status information, and user-space programs will receive | |
2727 | notification of APM "events" (e.g. battery status change). | |
2728 | ||
2729 | If you select "Y" here, you can disable actual use of the APM | |
2730 | BIOS by passing the "apm=off" option to the kernel at boot time. | |
2731 | ||
2732 | Note that the APM support is almost completely disabled for | |
2733 | machines with more than one CPU. | |
2734 | ||
2735 | In order to use APM, you will need supporting software. For location | |
151f4e2b | 2736 | and more information, read <file:Documentation/power/apm-acpi.rst> |
2dc98fd3 | 2737 | and the Battery Powered Linux mini-HOWTO, available from |
e279b6c1 SR |
2738 | <http://www.tldp.org/docs.html#howto>. |
2739 | ||
2740 | This driver does not spin down disk drives (see the hdparm(8) | |
2741 | manpage ("man 8 hdparm") for that), and it doesn't turn off | |
2742 | VESA-compliant "green" monitors. | |
2743 | ||
2744 | This driver does not support the TI 4000M TravelMate and the ACER | |
2745 | 486/DX4/75 because they don't have compliant BIOSes. Many "green" | |
2746 | desktop machines also don't have compliant BIOSes, and this driver | |
2747 | may cause those machines to panic during the boot phase. | |
2748 | ||
2749 | Generally, if you don't have a battery in your machine, there isn't | |
2750 | much point in using this driver and you should say N. If you get | |
2751 | random kernel OOPSes or reboots that don't seem to be related to | |
2752 | anything, try disabling/enabling this option (or disabling/enabling | |
2753 | APM in your BIOS). | |
2754 | ||
2755 | Some other things you should try when experiencing seemingly random, | |
2756 | "weird" problems: | |
2757 | ||
2758 | 1) make sure that you have enough swap space and that it is | |
2759 | enabled. | |
7987448f | 2760 | 2) pass the "idle=poll" option to the kernel |
e279b6c1 SR |
2761 | 3) switch on floating point emulation in the kernel and pass |
2762 | the "no387" option to the kernel | |
2763 | 4) pass the "floppy=nodma" option to the kernel | |
2764 | 5) pass the "mem=4M" option to the kernel (thereby disabling | |
2765 | all but the first 4 MB of RAM) | |
2766 | 6) make sure that the CPU is not over clocked. | |
2767 | 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> | |
2768 | 8) disable the cache from your BIOS settings | |
2769 | 9) install a fan for the video card or exchange video RAM | |
2770 | 10) install a better fan for the CPU | |
2771 | 11) exchange RAM chips | |
2772 | 12) exchange the motherboard. | |
2773 | ||
2774 | To compile this driver as a module, choose M here: the | |
2775 | module will be called apm. | |
2776 | ||
2777 | if APM | |
2778 | ||
2779 | config APM_IGNORE_USER_SUSPEND | |
2780 | bool "Ignore USER SUSPEND" | |
a7f7f624 | 2781 | help |
e279b6c1 SR |
2782 | This option will ignore USER SUSPEND requests. On machines with a |
2783 | compliant APM BIOS, you want to say N. However, on the NEC Versa M | |
2784 | series notebooks, it is necessary to say Y because of a BIOS bug. | |
2785 | ||
2786 | config APM_DO_ENABLE | |
2787 | bool "Enable PM at boot time" | |
a7f7f624 | 2788 | help |
e279b6c1 SR |
2789 | Enable APM features at boot time. From page 36 of the APM BIOS |
2790 | specification: "When disabled, the APM BIOS does not automatically | |
2791 | power manage devices, enter the Standby State, enter the Suspend | |
2792 | State, or take power saving steps in response to CPU Idle calls." | |
2793 | This driver will make CPU Idle calls when Linux is idle (unless this | |
2794 | feature is turned off -- see "Do CPU IDLE calls", below). This | |
2795 | should always save battery power, but more complicated APM features | |
2796 | will be dependent on your BIOS implementation. You may need to turn | |
2797 | this option off if your computer hangs at boot time when using APM | |
2798 | support, or if it beeps continuously instead of suspending. Turn | |
2799 | this off if you have a NEC UltraLite Versa 33/C or a Toshiba | |
2800 | T400CDT. This is off by default since most machines do fine without | |
2801 | this feature. | |
2802 | ||
2803 | config APM_CPU_IDLE | |
dd8af076 | 2804 | depends on CPU_IDLE |
e279b6c1 | 2805 | bool "Make CPU Idle calls when idle" |
a7f7f624 | 2806 | help |
e279b6c1 SR |
2807 | Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. |
2808 | On some machines, this can activate improved power savings, such as | |
2809 | a slowed CPU clock rate, when the machine is idle. These idle calls | |
2810 | are made after the idle loop has run for some length of time (e.g., | |
2811 | 333 mS). On some machines, this will cause a hang at boot time or | |
2812 | whenever the CPU becomes idle. (On machines with more than one CPU, | |
2813 | this option does nothing.) | |
2814 | ||
2815 | config APM_DISPLAY_BLANK | |
2816 | bool "Enable console blanking using APM" | |
a7f7f624 | 2817 | help |
e279b6c1 SR |
2818 | Enable console blanking using the APM. Some laptops can use this to |
2819 | turn off the LCD backlight when the screen blanker of the Linux | |
2820 | virtual console blanks the screen. Note that this is only used by | |
2821 | the virtual console screen blanker, and won't turn off the backlight | |
2822 | when using the X Window system. This also doesn't have anything to | |
2823 | do with your VESA-compliant power-saving monitor. Further, this | |
2824 | option doesn't work for all laptops -- it might not turn off your | |
2825 | backlight at all, or it might print a lot of errors to the console, | |
2826 | especially if you are using gpm. | |
2827 | ||
2828 | config APM_ALLOW_INTS | |
2829 | bool "Allow interrupts during APM BIOS calls" | |
a7f7f624 | 2830 | help |
e279b6c1 SR |
2831 | Normally we disable external interrupts while we are making calls to |
2832 | the APM BIOS as a measure to lessen the effects of a badly behaving | |
2833 | BIOS implementation. The BIOS should reenable interrupts if it | |
2834 | needs to. Unfortunately, some BIOSes do not -- especially those in | |
2835 | many of the newer IBM Thinkpads. If you experience hangs when you | |
2836 | suspend, try setting this to Y. Otherwise, say N. | |
2837 | ||
e279b6c1 SR |
2838 | endif # APM |
2839 | ||
bb0a56ec | 2840 | source "drivers/cpufreq/Kconfig" |
e279b6c1 SR |
2841 | |
2842 | source "drivers/cpuidle/Kconfig" | |
2843 | ||
27471fdb AH |
2844 | source "drivers/idle/Kconfig" |
2845 | ||
e279b6c1 SR |
2846 | endmenu |
2847 | ||
e279b6c1 SR |
2848 | menu "Bus options (PCI etc.)" |
2849 | ||
e279b6c1 SR |
2850 | choice |
2851 | prompt "PCI access mode" | |
efefa6f6 | 2852 | depends on X86_32 && PCI |
e279b6c1 | 2853 | default PCI_GOANY |
a7f7f624 | 2854 | help |
e279b6c1 SR |
2855 | On PCI systems, the BIOS can be used to detect the PCI devices and |
2856 | determine their configuration. However, some old PCI motherboards | |
2857 | have BIOS bugs and may crash if this is done. Also, some embedded | |
2858 | PCI-based systems don't have any BIOS at all. Linux can also try to | |
2859 | detect the PCI hardware directly without using the BIOS. | |
2860 | ||
2861 | With this option, you can specify how Linux should detect the | |
2862 | PCI devices. If you choose "BIOS", the BIOS will be used, | |
2863 | if you choose "Direct", the BIOS won't be used, and if you | |
2864 | choose "MMConfig", then PCI Express MMCONFIG will be used. | |
2865 | If you choose "Any", the kernel will try MMCONFIG, then the | |
2866 | direct access method and falls back to the BIOS if that doesn't | |
2867 | work. If unsure, go with the default, which is "Any". | |
2868 | ||
2869 | config PCI_GOBIOS | |
2870 | bool "BIOS" | |
2871 | ||
2872 | config PCI_GOMMCONFIG | |
2873 | bool "MMConfig" | |
2874 | ||
2875 | config PCI_GODIRECT | |
2876 | bool "Direct" | |
2877 | ||
3ef0e1f8 | 2878 | config PCI_GOOLPC |
76fb6570 | 2879 | bool "OLPC XO-1" |
3ef0e1f8 AS |
2880 | depends on OLPC |
2881 | ||
2bdd1b03 AS |
2882 | config PCI_GOANY |
2883 | bool "Any" | |
2884 | ||
e279b6c1 SR |
2885 | endchoice |
2886 | ||
2887 | config PCI_BIOS | |
3c2362e6 | 2888 | def_bool y |
efefa6f6 | 2889 | depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) |
e279b6c1 SR |
2890 | |
2891 | # x86-64 doesn't support PCI BIOS access from long mode so always go direct. | |
2892 | config PCI_DIRECT | |
3c2362e6 | 2893 | def_bool y |
0aba496f | 2894 | depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) |
e279b6c1 SR |
2895 | |
2896 | config PCI_MMCONFIG | |
b45c9f36 JK |
2897 | bool "Support mmconfig PCI config space access" if X86_64 |
2898 | default y | |
4590d98f | 2899 | depends on PCI && (ACPI || JAILHOUSE_GUEST) |
b45c9f36 | 2900 | depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) |
21d8fb8d MJ |
2901 | help |
2902 | Add support for accessing the PCI configuration space as a memory | |
2903 | mapped area. It is the recommended method if the system supports | |
2904 | this (it must have PCI Express and ACPI for it to be available). | |
2905 | ||
2906 | In the unlikely case that enabling this configuration option causes | |
2907 | problems, the mechanism can be switched off with the 'pci=nommconf' | |
2908 | command line parameter. | |
2909 | ||
2910 | Say N only if you are sure that your platform does not support this | |
2911 | access method or you have problems caused by it. | |
2912 | ||
2913 | Say Y otherwise. | |
e279b6c1 | 2914 | |
3ef0e1f8 | 2915 | config PCI_OLPC |
2bdd1b03 AS |
2916 | def_bool y |
2917 | depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) | |
3ef0e1f8 | 2918 | |
b5401a96 AN |
2919 | config PCI_XEN |
2920 | def_bool y | |
2921 | depends on PCI && XEN | |
b5401a96 | 2922 | |
8364e1f8 JK |
2923 | config MMCONF_FAM10H |
2924 | def_bool y | |
2925 | depends on X86_64 && PCI_MMCONFIG && ACPI | |
e279b6c1 | 2926 | |
3f6ea84a | 2927 | config PCI_CNB20LE_QUIRK |
d9f87802 MJ |
2928 | bool "Read PCI host bridge windows from the CNB20LE chipset" if EXPERT |
2929 | depends on X86_32 && PCI | |
3f6ea84a IS |
2930 | help |
2931 | Read the PCI windows out of the CNB20LE host bridge. This allows | |
2932 | PCI hotplug to work on systems with the CNB20LE chipset which do | |
2933 | not have ACPI. | |
2934 | ||
d9f87802 MJ |
2935 | The ServerWorks (later Broadcom) CNB20LE was a chipset designed |
2936 | most probably only for Pentium III. | |
2937 | ||
2938 | To find out if you have such a chipset, search for a PCI device with | |
2939 | 1166:0009 PCI IDs, for example by executing | |
2940 | lspci -nn | grep '1166:0009' | |
2941 | The code is inactive if there is none. | |
2942 | ||
64a5fed6 BH |
2943 | There's no public spec for this chipset, and this functionality |
2944 | is known to be incomplete. | |
2945 | ||
2946 | You should say N unless you know you need this. | |
2947 | ||
3a495511 | 2948 | config ISA_BUS |
17a2a129 | 2949 | bool "ISA bus support on modern systems" if EXPERT |
3a495511 | 2950 | help |
17a2a129 WBG |
2951 | Expose ISA bus device drivers and options available for selection and |
2952 | configuration. Enable this option if your target machine has an ISA | |
2953 | bus. ISA is an older system, displaced by PCI and newer bus | |
2954 | architectures -- if your target machine is modern, it probably does | |
2955 | not have an ISA bus. | |
3a495511 WBG |
2956 | |
2957 | If unsure, say N. | |
2958 | ||
1c00f016 | 2959 | # x86_64 have no ISA slots, but can have ISA-style DMA. |
e279b6c1 | 2960 | config ISA_DMA_API |
1c00f016 DR |
2961 | bool "ISA-style DMA support" if (X86_64 && EXPERT) |
2962 | default y | |
2963 | help | |
2964 | Enables ISA-style DMA support for devices requiring such controllers. | |
2965 | If unsure, say Y. | |
e279b6c1 | 2966 | |
51e68d05 LT |
2967 | if X86_32 |
2968 | ||
e279b6c1 SR |
2969 | config ISA |
2970 | bool "ISA support" | |
a7f7f624 | 2971 | help |
e279b6c1 SR |
2972 | Find out whether you have ISA slots on your motherboard. ISA is the |
2973 | name of a bus system, i.e. the way the CPU talks to the other stuff | |
2974 | inside your box. Other bus systems are PCI, EISA, MicroChannel | |
2975 | (MCA) or VESA. ISA is an older system, now being displaced by PCI; | |
2976 | newer boards don't support it. If you have ISA, say Y, otherwise N. | |
2977 | ||
e279b6c1 SR |
2978 | config SCx200 |
2979 | tristate "NatSemi SCx200 support" | |
a7f7f624 | 2980 | help |
e279b6c1 SR |
2981 | This provides basic support for National Semiconductor's |
2982 | (now AMD's) Geode processors. The driver probes for the | |
2983 | PCI-IDs of several on-chip devices, so its a good dependency | |
2984 | for other scx200_* drivers. | |
2985 | ||
2986 | If compiled as a module, the driver is named scx200. | |
2987 | ||
2988 | config SCx200HR_TIMER | |
2989 | tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" | |
592913ec | 2990 | depends on SCx200 |
e279b6c1 | 2991 | default y |
a7f7f624 | 2992 | help |
e279b6c1 SR |
2993 | This driver provides a clocksource built upon the on-chip |
2994 | 27MHz high-resolution timer. Its also a workaround for | |
2995 | NSC Geode SC-1100's buggy TSC, which loses time when the | |
2996 | processor goes idle (as is done by the scheduler). The | |
2997 | other workaround is idle=poll boot option. | |
2998 | ||
3ef0e1f8 AS |
2999 | config OLPC |
3000 | bool "One Laptop Per Child support" | |
54008979 | 3001 | depends on !X86_PAE |
3c554946 | 3002 | select GPIOLIB |
dc3119e7 | 3003 | select OF |
45bb1674 | 3004 | select OF_PROMTREE |
b4e51854 | 3005 | select IRQ_DOMAIN |
0c3d931b | 3006 | select OLPC_EC |
a7f7f624 | 3007 | help |
3ef0e1f8 AS |
3008 | Add support for detecting the unique features of the OLPC |
3009 | XO hardware. | |
3010 | ||
a3128588 DD |
3011 | config OLPC_XO1_PM |
3012 | bool "OLPC XO-1 Power Management" | |
fa112cf1 | 3013 | depends on OLPC && MFD_CS5535=y && PM_SLEEP |
a7f7f624 | 3014 | help |
97c4cb71 | 3015 | Add support for poweroff and suspend of the OLPC XO-1 laptop. |
bf1ebf00 | 3016 | |
cfee9597 DD |
3017 | config OLPC_XO1_RTC |
3018 | bool "OLPC XO-1 Real Time Clock" | |
3019 | depends on OLPC_XO1_PM && RTC_DRV_CMOS | |
a7f7f624 | 3020 | help |
cfee9597 DD |
3021 | Add support for the XO-1 real time clock, which can be used as a |
3022 | programmable wakeup source. | |
3023 | ||
7feda8e9 DD |
3024 | config OLPC_XO1_SCI |
3025 | bool "OLPC XO-1 SCI extras" | |
92e830f2 | 3026 | depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y |
ed8e47fe | 3027 | depends on INPUT=y |
d8d01a63 | 3028 | select POWER_SUPPLY |
a7f7f624 | 3029 | help |
7feda8e9 | 3030 | Add support for SCI-based features of the OLPC XO-1 laptop: |
7bc74b3d | 3031 | - EC-driven system wakeups |
7feda8e9 | 3032 | - Power button |
7bc74b3d | 3033 | - Ebook switch |
2cf2baea | 3034 | - Lid switch |
e1040ac6 DD |
3035 | - AC adapter status updates |
3036 | - Battery status updates | |
7feda8e9 | 3037 | |
a0f30f59 DD |
3038 | config OLPC_XO15_SCI |
3039 | bool "OLPC XO-1.5 SCI extras" | |
d8d01a63 DD |
3040 | depends on OLPC && ACPI |
3041 | select POWER_SUPPLY | |
a7f7f624 | 3042 | help |
a0f30f59 DD |
3043 | Add support for SCI-based features of the OLPC XO-1.5 laptop: |
3044 | - EC-driven system wakeups | |
3045 | - AC adapter status updates | |
3046 | - Battery status updates | |
bf1ebf00 | 3047 | |
298c9bab DT |
3048 | config GEODE_COMMON |
3049 | bool | |
3050 | ||
d4f3e350 EW |
3051 | config ALIX |
3052 | bool "PCEngines ALIX System Support (LED setup)" | |
3053 | select GPIOLIB | |
298c9bab | 3054 | select GEODE_COMMON |
a7f7f624 | 3055 | help |
d4f3e350 EW |
3056 | This option enables system support for the PCEngines ALIX. |
3057 | At present this just sets up LEDs for GPIO control on | |
3058 | ALIX2/3/6 boards. However, other system specific setup should | |
3059 | get added here. | |
3060 | ||
3061 | Note: You must still enable the drivers for GPIO and LED support | |
3062 | (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs | |
3063 | ||
3064 | Note: You have to set alix.force=1 for boards with Award BIOS. | |
3065 | ||
da4e3302 PP |
3066 | config NET5501 |
3067 | bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" | |
3068 | select GPIOLIB | |
298c9bab | 3069 | select GEODE_COMMON |
a7f7f624 | 3070 | help |
da4e3302 PP |
3071 | This option enables system support for the Soekris Engineering net5501. |
3072 | ||
3197059a PP |
3073 | config GEOS |
3074 | bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" | |
3075 | select GPIOLIB | |
298c9bab | 3076 | select GEODE_COMMON |
3197059a | 3077 | depends on DMI |
a7f7f624 | 3078 | help |
3197059a PP |
3079 | This option enables system support for the Traverse Technologies GEOS. |
3080 | ||
7d029125 VD |
3081 | config TS5500 |
3082 | bool "Technologic Systems TS-5500 platform support" | |
3083 | depends on MELAN | |
3084 | select CHECK_SIGNATURE | |
3085 | select NEW_LEDS | |
3086 | select LEDS_CLASS | |
a7f7f624 | 3087 | help |
7d029125 VD |
3088 | This option enables system support for the Technologic Systems TS-5500. |
3089 | ||
bc0120fd SR |
3090 | endif # X86_32 |
3091 | ||
23ac4ae8 | 3092 | config AMD_NB |
e6e6e5e8 YG |
3093 | def_bool y |
3094 | depends on AMD_NODE | |
3095 | ||
3096 | config AMD_NODE | |
e279b6c1 | 3097 | def_bool y |
0e152cd7 | 3098 | depends on CPU_SUP_AMD && PCI |
e279b6c1 | 3099 | |
e279b6c1 SR |
3100 | endmenu |
3101 | ||
1572497c | 3102 | menu "Binary Emulations" |
e279b6c1 SR |
3103 | |
3104 | config IA32_EMULATION | |
3105 | bool "IA32 Emulation" | |
3106 | depends on X86_64 | |
39f88911 | 3107 | select ARCH_WANT_OLD_COMPAT_IPC |
d1603990 | 3108 | select BINFMT_ELF |
39f88911 | 3109 | select COMPAT_OLD_SIGACTION |
a7f7f624 | 3110 | help |
5fd92e65 L |
3111 | Include code to run legacy 32-bit programs under a |
3112 | 64-bit kernel. You should likely turn this on, unless you're | |
3113 | 100% sure that you don't have any 32-bit programs left. | |
e279b6c1 | 3114 | |
a11e0975 NB |
3115 | config IA32_EMULATION_DEFAULT_DISABLED |
3116 | bool "IA32 emulation disabled by default" | |
3117 | default n | |
3118 | depends on IA32_EMULATION | |
3119 | help | |
3120 | Make IA32 emulation disabled by default. This prevents loading 32-bit | |
3121 | processes and access to 32-bit syscalls. If unsure, leave it to its | |
3122 | default value. | |
3123 | ||
83a44a4f | 3124 | config X86_X32_ABI |
6ea30386 | 3125 | bool "x32 ABI for 64-bit mode" |
9b54050b | 3126 | depends on X86_64 |
aaeed6ec NC |
3127 | # llvm-objcopy does not convert x86_64 .note.gnu.property or |
3128 | # compressed debug sections to x86_x32 properly: | |
3129 | # https://github.com/ClangBuiltLinux/linux/issues/514 | |
3130 | # https://github.com/ClangBuiltLinux/linux/issues/1141 | |
3131 | depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) | |
a7f7f624 | 3132 | help |
5fd92e65 L |
3133 | Include code to run binaries for the x32 native 32-bit ABI |
3134 | for 64-bit processors. An x32 process gets access to the | |
3135 | full 64-bit register file and wide data path while leaving | |
3136 | pointers at 32 bits for smaller memory footprint. | |
3137 | ||
953fee1d IM |
3138 | config COMPAT_32 |
3139 | def_bool y | |
3140 | depends on IA32_EMULATION || X86_32 | |
3141 | select HAVE_UID16 | |
3142 | select OLD_SIGSUSPEND3 | |
3143 | ||
e279b6c1 | 3144 | config COMPAT |
3c2362e6 | 3145 | def_bool y |
83a44a4f | 3146 | depends on IA32_EMULATION || X86_X32_ABI |
e279b6c1 SR |
3147 | |
3148 | config COMPAT_FOR_U64_ALIGNMENT | |
3120e25e | 3149 | def_bool y |
a9251280 | 3150 | depends on COMPAT |
ee009e4a | 3151 | |
e279b6c1 SR |
3152 | endmenu |
3153 | ||
e5beae16 KP |
3154 | config HAVE_ATOMIC_IOMAP |
3155 | def_bool y | |
3156 | depends on X86_32 | |
3157 | ||
edf88417 | 3158 | source "arch/x86/kvm/Kconfig" |
5e8ebd84 | 3159 | |
3d37d939 PAI |
3160 | source "arch/x86/Kconfig.cpufeatures" |
3161 | ||
5e8ebd84 | 3162 | source "arch/x86/Kconfig.assembler" |