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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001# SPDX-License-Identifier: GPL-2.0
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01002# Select 32 or 64 bit
3config 64BIT
Masahiro Yamada104daea2018-05-28 18:21:40 +09004 bool "64-bit kernel" if "$(ARCH)" = "x86"
5 default "$(ARCH)" != "i386"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09006 help
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01007 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
10config X86_32
Jan Beulich3120e252012-09-10 12:41:45 +010011 def_bool y
12 depends on !64BIT
Ingo Molnar341c7872016-11-15 10:04:55 +010013 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
Thomas Gleixner157e1182020-11-03 10:27:20 +010017 select GENERIC_VDSO_32
Thomas Gleixner117ed452019-04-14 18:00:08 +020018 select HAVE_DEBUG_STACKOVERFLOW
Thomas Gleixner157e1182020-11-03 10:27:20 +010019 select KMAP_LOCAL
Ingo Molnar341c7872016-11-15 10:04:55 +010020 select MODULES_USE_ELF_REL
21 select OLD_SIGACTION
Brian Gerst2ca408d2020-11-30 17:30:59 -050022 select ARCH_SPLIT_ARG64
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +010023
24config X86_64
Jan Beulich3120e252012-09-10 12:41:45 +010025 def_bool y
26 depends on 64BIT
Ingo Molnard94e0682016-11-15 10:11:57 +010027 # Options that are inherently 64-bit kernel only:
Alexandre Ghiti4eb07162019-05-13 17:19:04 -070028 select ARCH_HAS_GIGANTIC_PAGE
Ard Biesheuvelc12d3362019-11-08 13:22:27 +010029 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
Suren Baghdasaryan0bff0aa2023-02-27 09:36:28 -080030 select ARCH_SUPPORTS_PER_VMA_LOCK
Ingo Molnard94e0682016-11-15 10:11:57 +010031 select ARCH_USE_CMPXCHG_LOCKREF
32 select HAVE_ARCH_SOFT_DIRTY
33 select MODULES_USE_ELF_RELA
Christoph Hellwigf616ab52018-05-09 06:53:49 +020034 select NEED_DMA_MAP_STATE
Christoph Hellwig09230cb2018-04-24 09:00:54 +020035 select SWIOTLB
Al Viro7facdc42020-06-13 23:03:25 -040036 select ARCH_HAS_ELFCORE_COMPAT
Kefeng Wang63703f32021-06-30 18:52:20 -070037 select ZONE_DMA32
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010038
Steven Rostedt (VMware)518049d2019-05-10 12:05:46 -040039config FORCE_DYNAMIC_FTRACE
40 def_bool y
41 depends on X86_32
42 depends on FUNCTION_TRACER
43 select DYNAMIC_FTRACE
44 help
Juerg Haefliger758cd942022-05-25 15:32:02 +020045 We keep the static function tracing (!DYNAMIC_FTRACE) around
46 in order to test the non static function tracing in the
47 generic code, as other architectures still use it. But we
48 only need to keep it around for x86_64. No need to keep it
49 for x86_32. For x86_32, force DYNAMIC_FTRACE.
Ingo Molnard94e0682016-11-15 10:11:57 +010050#
51# Arch settings
52#
53# ( Note that options that are marked 'if X86_64' could in principle be
54# ported to 32-bit as well. )
55#
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010056config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010057 def_bool y
Ingo Molnarc763ea22016-11-15 10:26:39 +010058 #
59 # Note: keep this list sorted alphabetically
60 #
Ingo Molnar6471b822015-06-03 10:00:13 +020061 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
62 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
Yury Norov942fa982018-05-16 11:18:49 +030063 select ARCH_32BIT_OFF_T if X86_32
Thomas Gleixner2a21ad52018-09-17 14:45:35 +020064 select ARCH_CLOCKSOURCE_INIT
Masami Hiramatsu1f6d3a82021-10-25 20:41:52 +090065 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
Anshuman Khandual1e866972021-05-04 18:38:21 -070066 select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
David Hildenbrand5c11f00b2021-11-05 13:44:39 -070067 select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
Anshuman Khandual91024b32021-05-04 18:38:17 -070068 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
Anshuman Khandualcebc7742021-06-30 18:51:58 -070069 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
Anshuman Khandual1e866972021-05-04 18:38:21 -070070 select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
Ingo Molnarc763ea22016-11-15 10:26:39 +010071 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
Anshuman Khandualc2280be2021-05-04 18:38:09 -070072 select ARCH_HAS_CACHE_LINE_SIZE
Davidlohr Bueso1156b442022-10-28 11:34:04 -070073 select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
Thomas Gleixner7c7077a2023-06-14 01:39:24 +020074 select ARCH_HAS_CPU_FINALIZE_INIT
Kees Cook2792d842022-02-16 12:05:28 -080075 select ARCH_HAS_CURRENT_STACK_POINTER
Laura Abbottfa5b6ec2017-01-10 13:35:40 -080076 select ARCH_HAS_DEBUG_VIRTUAL
Anshuman Khandual399145f2020-06-04 16:47:15 -070077 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
Dan Williams21266be2015-11-19 18:19:29 -080078 select ARCH_HAS_DEVMEM_IS_ALLOWED
Douglas Andersonb1a57bb2020-05-07 13:08:42 -070079 select ARCH_HAS_EARLY_DEBUG if KGDB
Ingo Molnar6471b822015-06-03 10:00:13 +020080 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070081 select ARCH_HAS_FAST_MULTIPLIER
Daniel Micay6974f0c2017-07-12 14:36:10 -070082 select ARCH_HAS_FORTIFY_SOURCE
Riku Voipio957e3fa2014-12-12 16:57:44 -080083 select ARCH_HAS_GCOV_PROFILE_ALL
Marco Elverbece04b2022-01-19 18:10:31 -080084 select ARCH_HAS_KCOV if X86_64
Thiago Jung Bauermann0c9c1d52019-08-06 01:49:14 -030085 select ARCH_HAS_MEM_ENCRYPT
Mathieu Desnoyers10bcc802018-01-29 15:20:18 -050086 select ARCH_HAS_MEMBARRIER_SYNC_CORE
Paul E. McKenney49f88c72022-09-28 11:11:18 -070087 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
Daniel Borkmann0ebeea82020-05-15 12:11:16 +020088 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
Ingo Molnarc763ea22016-11-15 10:26:39 +010089 select ARCH_HAS_PMEM_API if X86_64
Robin Murphy17596732019-07-16 16:30:47 -070090 select ARCH_HAS_PTE_DEVMAP if X86_64
Laurent Dufour3010a5e2018-06-07 17:06:08 -070091 select ARCH_HAS_PTE_SPECIAL
Yu Zhaoeed9a322022-09-18 01:59:59 -060092 select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2
Dan Williams0aed55a2017-05-29 12:22:50 -070093 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
Dan Williamsec6347b2020-10-05 20:40:16 -070094 select ARCH_HAS_COPY_MC if X86_64
Daniel Borkmannd2852a22017-02-21 16:09:33 +010095 select ARCH_HAS_SET_MEMORY
Rick Edgecombed253ca02019-04-25 17:11:34 -070096 select ARCH_HAS_SET_DIRECT_MAP
Laura Abbottad21fc42017-02-06 16:31:57 -080097 select ARCH_HAS_STRICT_KERNEL_RWX
98 select ARCH_HAS_STRICT_MODULE_RWX
Mathieu Desnoyersac1ab122018-01-29 15:20:16 -050099 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
Brian Gerst25c619e52020-03-13 15:51:42 -0400100 select ARCH_HAS_SYSCALL_WRAPPER
Andrey Ryabininc6d30852016-01-20 15:00:55 -0800101 select ARCH_HAS_UBSAN_SANITIZE_ALL
Zong Li7e01ccb2020-06-03 16:03:58 -0700102 select ARCH_HAS_DEBUG_WX
Kefeng Wang63703f32021-06-30 18:52:20 -0700103 select ARCH_HAS_ZONE_DMA_SET if EXPERT
Ingo Molnar6471b822015-06-03 10:00:13 +0200104 select ARCH_HAVE_NMI_SAFE_CMPXCHG
Aneesh Kumar K.V04d5ea42023-08-08 14:44:56 +0530105 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
Ingo Molnar6471b822015-06-03 10:00:13 +0200106 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -0400107 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -0800108 select ARCH_MIGHT_HAVE_PC_SERIO
Thomas Gleixner3599fe12019-04-25 11:45:22 +0200109 select ARCH_STACKWALK
Arnd Bergmann2c870e62018-07-24 11:48:45 +0200110 select ARCH_SUPPORTS_ACPI
Ingo Molnar6471b822015-06-03 10:00:13 +0200111 select ARCH_SUPPORTS_ATOMIC_RMW
Mike Rapoport5d6ad662020-12-14 19:10:30 -0800112 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
Pasha Tatashind283d422022-01-14 14:06:41 -0800113 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200114 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
Thomas Gleixner14df3262020-11-18 20:48:41 +0100115 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096
Sami Tolvanen3c516f82022-09-08 14:55:04 -0700116 select ARCH_SUPPORTS_CFI_CLANG if X86_64
117 select ARCH_USES_CFI_TRAPS if X86_64 && CFI_CLANG
Nathan Chancellor583bfd42021-04-29 16:26:12 -0700118 select ARCH_SUPPORTS_LTO_CLANG
119 select ARCH_SUPPORTS_LTO_CLANG_THIN
Ingo Molnar6471b822015-06-03 10:00:13 +0200120 select ARCH_USE_BUILTIN_BSWAP
Anshuman Khandualdce44562021-04-29 22:55:15 -0700121 select ARCH_USE_MEMTEST
Ingo Molnar6471b822015-06-03 10:00:13 +0200122 select ARCH_USE_QUEUED_RWLOCKS
123 select ARCH_USE_QUEUED_SPINLOCKS
Mark Brown2ce0d7f2020-04-16 19:24:02 +0100124 select ARCH_USE_SYM_ANNOTATIONS
Andy Lutomirskice4a4e562017-05-28 10:00:14 -0700125 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
Daniel Borkmann81c22042019-12-09 16:08:03 +0100126 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100127 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Nick Desaulniers51c2ee62021-06-21 16:18:22 -0700128 select ARCH_WANTS_NO_INSTR
Anshuman Khandual07431502022-03-22 14:45:15 -0700129 select ARCH_WANT_GENERAL_HUGETLB
Alexandre Ghiti3876d4a2019-06-27 15:00:11 -0700130 select ARCH_WANT_HUGE_PMD_SHARE
Nathan Chancellor59612b22020-11-19 13:46:56 -0700131 select ARCH_WANT_LD_ORPHAN_WARN
Aneesh Kumar K.V0b6f1582023-07-25 00:37:53 +0530132 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64
133 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64
Huang Ying38d8b4e2017-07-06 15:37:18 -0700134 select ARCH_WANTS_THP_SWAP if X86_64
Balbir Singhb5f06f62021-04-26 21:42:30 +0200135 select ARCH_HAS_PARANOID_L1D_FLUSH
Shile Zhang10916702019-12-04 08:46:31 +0800136 select BUILDTIME_TABLE_SORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200137 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +0200138 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
139 select CLOCKSOURCE_WATCHDOG
Alexander Potapenko7cf8f442022-09-15 17:04:12 +0200140 # Word-size accesses may read uninitialized data past the trailing \0
141 # in strings and cause false KMSAN reports.
142 select DCACHE_WORD_ACCESS if !KMSAN
Thomas Gleixner3aac3eb2021-10-21 15:55:06 -0700143 select DYNAMIC_SIGFRAME
Linus Torvalds45471cd2015-06-24 19:52:06 -0700144 select EDAC_ATOMIC_SCRUB
145 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200146 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
147 select GENERIC_CLOCKEVENTS_MIN_ADJUST
148 select GENERIC_CMOS_UPDATE
149 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +0100150 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +0200151 select GENERIC_EARLY_IOREMAP
Thomas Gleixner27d6b4d2020-07-23 00:00:04 +0200152 select GENERIC_ENTRY
Ingo Molnar6471b822015-06-03 10:00:13 +0200153 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +0200154 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +0200155 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +0200156 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200157 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200158 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200159 select GENERIC_IRQ_SHOW
160 select GENERIC_PENDING_IRQ if SMP
Steven Price2ae27132020-02-03 17:36:24 -0800161 select GENERIC_PTDUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200162 select GENERIC_SMP_IDLE_THREAD
Ingo Molnar6471b822015-06-03 10:00:13 +0200163 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100164 select GENERIC_GETTIMEOFDAY
Dmitry Safonov550a77a2019-11-12 01:27:11 +0000165 select GENERIC_VDSO_TIME_NS
Peter Zijlstra6ca297d2022-10-21 14:51:44 +0200166 select GUP_GET_PXX_LOW_HIGH if X86_PAE
Hans de Goede17e58882020-01-23 22:02:42 +0100167 select HARDIRQS_SW_RESEND
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200168 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Niklas Schnellefcbfe812023-03-23 17:33:52 +0100169 select HAS_IOPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200170 select HAVE_ACPI_APEI if ACPI
171 select HAVE_ACPI_APEI_NMI if ACPI
172 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200173 select HAVE_ARCH_AUDITSYSCALL
174 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
Song Liueed1fce2022-03-02 09:51:25 -0800175 select HAVE_ARCH_HUGE_VMALLOC if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200176 select HAVE_ARCH_JUMP_LABEL
Ard Biesheuvelb34006c2018-09-18 23:51:41 -0700177 select HAVE_ARCH_JUMP_LABEL_RELATIVE
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800178 select HAVE_ARCH_KASAN if X86_64
Daniel Axtens0609ae02019-11-30 17:55:00 -0800179 select HAVE_ARCH_KASAN_VMALLOC if X86_64
Alexander Potapenko1dc0da62021-02-25 17:18:57 -0800180 select HAVE_ARCH_KFENCE
Alexander Potapenko4ca8cc82022-09-15 17:04:17 +0200181 select HAVE_ARCH_KMSAN if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200182 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800183 select HAVE_ARCH_MMAP_RND_BITS if MMU
184 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300185 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700186 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200187 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700188 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300189 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200190 select HAVE_ARCH_TRACEHOOK
191 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800192 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Peter Xub64d8d12020-04-20 18:13:45 -0700193 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD
Axel Rasmussen7677f7f2021-05-04 18:35:36 -0700194 select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700195 select HAVE_ARCH_VMAP_STACK if X86_64
Kees Cookfe950f62021-04-01 16:23:45 -0700196 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
Ingo Molnarc763ea22016-11-15 10:26:39 +0100197 select HAVE_ARCH_WITHIN_STACK_FRAMES
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900198 select HAVE_ASM_MODVERSIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200199 select HAVE_CMPXCHG_DOUBLE
200 select HAVE_CMPXCHG_LOCAL
Frederic Weisbecker24a9c5412022-06-08 16:40:24 +0200201 select HAVE_CONTEXT_TRACKING_USER if X86_64
202 select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER
Ingo Molnar6471b822015-06-03 10:00:13 +0200203 select HAVE_C_RECORDMCOUNT
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -0700204 select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
Sathvika Vasireddy280981d2022-11-14 23:27:49 +0530205 select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT
Steven Rostedt (Google)4ed308c2022-01-25 09:19:10 -0500206 select HAVE_BUILDTIME_MCOUNT_SORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200207 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700208 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400209 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900210 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt (VMware)02a474c2020-10-27 10:55:55 -0400211 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64
Steven Rostedt (VMware)562955f2019-11-08 13:11:39 -0500212 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
Heiko Carstensc316eb42021-10-12 15:38:01 +0200213 select HAVE_SAMPLE_FTRACE_DIRECT if X86_64
Heiko Carstens503e4512021-11-15 20:56:13 +0100214 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64
Wang YanQing03f57812018-05-03 14:10:43 +0800215 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700216 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100217 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700218 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700219 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400220 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200221 select HAVE_FTRACE_MCOUNT_RECORD
Donglin Pengd938ba12023-04-08 05:42:20 -0700222 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
Steven Rostedt (VMware)4a30e4c2021-10-20 23:35:55 -0400223 select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE)
Ingo Molnar6471b822015-06-03 10:00:13 +0200224 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200225 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530226 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200227 select HAVE_IOREMAP_PROT
Thomas Gleixner624db9e2021-02-10 00:40:51 +0100228 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200229 select HAVE_IRQ_TIME_ACCOUNTING
Josh Poimboeuf4ab76742022-04-18 09:50:39 -0700230 select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL
Ingo Molnar6471b822015-06-03 10:00:13 +0200231 select HAVE_KERNEL_BZIP2
232 select HAVE_KERNEL_GZIP
233 select HAVE_KERNEL_LZ4
234 select HAVE_KERNEL_LZMA
235 select HAVE_KERNEL_LZO
236 select HAVE_KERNEL_XZ
Nick Terrellfb46d052020-07-30 12:08:39 -0700237 select HAVE_KERNEL_ZSTD
Ingo Molnar6471b822015-06-03 10:00:13 +0200238 select HAVE_KPROBES
239 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900240 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200241 select HAVE_KRETPROBES
Masami Hiramatsuf3a112c2022-03-26 11:27:17 +0900242 select HAVE_RETHOOK
Ingo Molnar6471b822015-06-03 10:00:13 +0200243 select HAVE_KVM
244 select HAVE_LIVEPATCH if X86_64
Frederic Weisbecker01027522010-04-11 18:55:56 +0200245 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500246 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800247 select HAVE_MOVE_PMD
Kalesh Singhbe37c982020-12-14 19:07:40 -0800248 select HAVE_MOVE_PUD
Josh Poimboeuf22102f42022-04-18 09:50:40 -0700249 select HAVE_NOINSTR_HACK if HAVE_OBJTOOL
Petr Mladek42a0bb32016-05-20 17:00:33 -0700250 select HAVE_NMI
Josh Poimboeuf489e3552022-04-18 09:50:42 -0700251 select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -0700252 select HAVE_OBJTOOL if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200253 select HAVE_OPTPROBES
254 select HAVE_PCSPKR_PLATFORM
255 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200256 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700257 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100258 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200259 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200260 select HAVE_PERF_USER_STACK_DUMP
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -0700261 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
Peter Zijlstra1e9fdf22022-07-08 09:18:03 +0200262 select MMU_GATHER_MERGE_VMAS
Thomas Gleixner00998082020-07-30 12:14:07 +0200263 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
Ingo Molnar6471b822015-06-03 10:00:13 +0200264 select HAVE_REGS_AND_STACK_ACCESS_API
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -0700265 select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900266 select HAVE_FUNCTION_ARG_ACCESS_API
Kefeng Wang7ecd19c2022-01-19 18:07:41 -0800267 select HAVE_SETUP_PER_CPU_AREA
Thomas Gleixnercd1a41c2021-02-10 00:40:52 +0100268 select HAVE_SOFTIRQ_ON_OWN_STACK
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900269 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -0700270 select HAVE_STACK_VALIDATION if HAVE_OBJTOOL
Josh Poimboeufe6d6c072020-08-18 15:57:44 +0200271 select HAVE_STATIC_CALL
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -0700272 select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL
Mark Rutland99cf983c2022-02-14 16:52:14 +0000273 select HAVE_PREEMPT_DYNAMIC_CALL
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400274 select HAVE_RSEQ
Miguel Ojeda09498132022-08-04 12:16:44 +0200275 select HAVE_RUST if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200276 select HAVE_SYSCALL_TRACEPOINTS
Josh Poimboeuf5f3da8c2022-04-19 09:05:09 -0700277 select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL
Ingo Molnar6471b822015-06-03 10:00:13 +0200278 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300279 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100280 select HAVE_GENERIC_VDSO
Thomas Gleixner0c7ffa32023-05-12 23:07:56 +0200281 select HOTPLUG_PARALLEL if SMP && X86_64
Thomas Gleixner05736e42018-05-29 17:48:27 +0200282 select HOTPLUG_SMT if SMP
Thomas Gleixner0c7ffa32023-05-12 23:07:56 +0200283 select HOTPLUG_SPLIT_STARTUP if SMP && X86_32
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100284 select IRQ_FORCED_THREADING
Linus Torvaldsc2508ec2023-06-15 15:17:36 -0700285 select LOCK_MM_AND_FIND_VMA
Kefeng Wang7ecd19c2022-01-19 18:07:41 -0800286 select NEED_PER_CPU_EMBED_FIRST_CHUNK
287 select NEED_PER_CPU_PAGE_FIRST_CHUNK
Christoph Hellwig86596f02018-04-05 09:44:52 +0200288 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100289 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000290 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200291 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500292 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200293 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200294 select SPARSE_IRQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200295 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700296 select THREAD_INFO_IN_TASK
Masahiro Yamada4aae6832021-07-31 14:22:32 +0900297 select TRACE_IRQFLAGS_SUPPORT
Mark Rutland4510bff2022-05-11 14:17:32 +0100298 select TRACE_IRQFLAGS_NMI_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200299 select USER_STACKTRACE_SUPPORT
Ingo Molnar3b02a052020-04-13 09:44:39 +0200300 select HAVE_ARCH_KCSAN if X86_64
Aubrey Li0c608da2019-06-06 09:22:35 +0800301 select PROC_PID_ARCH_STATUS if PROC_FS
Jarkko Sakkinen50468e42021-11-16 18:21:16 +0200302 select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX
Peter Zijlstrad49a0622022-09-15 13:10:47 +0200303 select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16
304 select FUNCTION_ALIGNMENT_4B
Nayna Jain9e2b4be2020-03-08 20:57:51 -0400305 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
Jiri Olsaceea9912022-09-03 15:11:54 +0200306 select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
Balbir Singh7d8330a2008-02-10 12:46:28 +0530307
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200308config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100309 def_bool y
310 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200311
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700312config OUTPUT_FORMAT
313 string
314 default "elf32-i386" if X86_32
315 default "elf64-x86-64" if X86_64
316
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100317config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100318 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100319
320config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100321 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100322
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100323config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100324 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100325
Daniel Cashman9e08f572016-01-14 15:20:06 -0800326config ARCH_MMAP_RND_BITS_MIN
327 default 28 if 64BIT
328 default 8
329
330config ARCH_MMAP_RND_BITS_MAX
331 default 32 if 64BIT
332 default 16
333
334config ARCH_MMAP_RND_COMPAT_BITS_MIN
335 default 8
336
337config ARCH_MMAP_RND_COMPAT_BITS_MAX
338 default 16
339
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100340config SBUS
341 bool
342
343config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100344 def_bool y
345 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100346
Alexander Potapenkod911c672022-09-15 17:04:11 +0200347config GENERIC_CSUM
348 bool
349 default y if KMSAN || KASAN
350
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100351config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100352 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100353 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000354 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
355
356config GENERIC_BUG_RELATIVE_POINTERS
357 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100358
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100359config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100360 def_bool y
361 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100362
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100363config GENERIC_CALIBRATE_DELAY
364 def_bool y
365
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800366config ARCH_HAS_CPU_RELAX
367 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100368
Johannes Berg801e4062007-12-08 02:12:39 +0100369config ARCH_HIBERNATION_POSSIBLE
370 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100371
Johannes Bergf4cb5702007-12-08 02:14:00 +0100372config ARCH_SUSPEND_POSSIBLE
373 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100374
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100375config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000376 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100377
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300378config KASAN_SHADOW_OFFSET
379 hex
380 depends on KASAN
381 default 0xdffffc0000000000
382
Shane Wang69575d32009-09-01 18:25:07 -0700383config HAVE_INTEL_TXT
384 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700385 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700386
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100387config X86_32_SMP
388 def_bool y
389 depends on X86_32 && SMP
390
391config X86_64_SMP
392 def_bool y
393 depends on X86_64 && SMP
394
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530395config ARCH_SUPPORTS_UPROBES
396 def_bool y
397
Rob Herringd20642f2014-04-18 17:19:54 -0500398config FIX_EARLYCON_MEM
399 def_bool y
400
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +0300401config DYNAMIC_PHYSICAL_MASK
402 bool
403
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700404config PGTABLE_LEVELS
405 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300406 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700407 default 4 if X86_64
408 default 3 if X86_PAE
409 default 2
410
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900411config CC_HAS_SANE_STACKPROTECTOR
412 bool
Nathan Chancellor1b866782022-06-17 11:08:46 -0700413 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
414 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900415 help
Juerg Haefliger758cd942022-05-25 15:32:02 +0200416 We have to make sure stack protector is unconditionally disabled if
417 the compiler produces broken code or if it does not let us control
418 the segment on 32-bit kernels.
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900419
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100420menu "Processor type and features"
421
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100422config SMP
423 bool "Symmetric multi-processing support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900424 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100425 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800426 a system with only one CPU, say N. If you have a system with more
427 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100428
Robert Graffham4a474152014-01-23 15:55:29 -0800429 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100430 machines, but will use only one CPU of a multiprocessor machine. If
431 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800432 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100433 will run faster if you say N here.
434
435 Note that if you say Y here and choose architecture "586" or
436 "Pentium" under "Processor family", the kernel will not work on 486
437 architectures. Similarly, multiprocessor kernels for the "PPro"
438 architecture may not work on all Pentium based boards.
439
440 People using multiprocessor machines who say Y here should also say
441 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
442 Management" code will be disabled if you say Y here.
443
Jonathan Corbetff61f072023-03-14 17:06:44 -0600444 See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -0300445 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100446 <http://www.tldp.org/docs.html#howto>.
447
448 If you don't know what to do here, say N.
449
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800450config X86_X2APIC
451 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200452 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900453 help
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800454 This enables x2apic support on CPUs that have this feature.
455
456 This allows 32-bit apic IDs (so it can support very large systems),
457 and accesses the local apic via MSRs not via mmio.
458
Daniel Sneddonb8d1d162022-08-16 16:19:42 -0700459 Some Intel systems circa 2022 and later are locked into x2APIC mode
460 and can not fall back to the legacy APIC modes if SGX or TDX are
Mateusz Jończyke3998432022-11-29 22:50:08 +0100461 enabled in the BIOS. They will boot with very reduced functionality
462 without enabling this option.
Daniel Sneddonb8d1d162022-08-16 16:19:42 -0700463
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800464 If you don't know what to do here, say N.
465
Yinghai Lu6695c852008-06-19 12:13:09 -0700466config X86_MPPARSE
Andy Shevchenko4590d982021-02-11 15:40:02 +0200467 bool "Enable MPS table" if ACPI
Jan Beulich7a527682008-10-30 10:38:24 +0000468 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200469 depends on X86_LOCAL_APIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900470 help
Yinghai Lu6695c852008-06-19 12:13:09 -0700471 For old smp systems that do not have proper acpi support. Newer systems
472 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700473
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000474config GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100475 def_bool y
476 depends on X86_GOLDFISH
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000477
Johannes Weinere6d42932019-01-29 17:44:36 -0500478config X86_CPU_RESCTRL
479 bool "x86 CPU resource control support"
Babu Moger6fe07ce2018-11-21 20:28:39 +0000480 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100481 select KERNFS
Chen Yue79f15a2020-01-15 17:28:51 +0800482 select PROC_CPU_RESCTRL if PROC_FS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700483 help
Johannes Weinere6d42932019-01-29 17:44:36 -0500484 Enable x86 CPU resource control support.
Babu Moger6fe07ce2018-11-21 20:28:39 +0000485
486 Provide support for the allocation and monitoring of system resources
487 usage by the CPU.
488
489 Intel calls this Intel Resource Director Technology
490 (Intel(R) RDT). More information about RDT can be found in the
491 Intel x86 Architecture Software Developer Manual.
492
493 AMD calls this AMD Platform Quality of Service (AMD QoS).
494 More information about AMD QoS can be found in the AMD64 Technology
495 Platform Quality of Service Extensions manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700496
497 Say N if unsure.
498
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800499if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800500config X86_BIGSMP
501 bool "Support for big SMP systems with more than 8 CPUs"
502 depends on SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900503 help
Randy Dunlape133f6e2019-12-03 16:06:47 -0800504 This option is needed for the systems that have more than 8 CPUs.
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800505
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800506config X86_EXTENDED_PLATFORM
507 bool "Support for extended (non-PC) x86 platforms"
508 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900509 help
Ingo Molnar06ac8342009-01-27 18:11:43 +0100510 If you disable this option then the kernel will only support
511 standard PC platforms. (which covers the vast majority of
512 systems out there.)
513
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800514 If you enable this option then you'll be able to select support
515 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100516 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800517 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800518 RDC R-321x SoC
519 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200520 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200521 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100522
523 If you have one of these systems, or if you want to build a
524 generic distribution kernel, say Y here - otherwise say N.
Juerg Haefliger758cd942022-05-25 15:32:02 +0200525endif # X86_32
Ingo Molnar06ac8342009-01-27 18:11:43 +0100526
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800527if X86_64
528config X86_EXTENDED_PLATFORM
529 bool "Support for extended (non-PC) x86 platforms"
530 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900531 help
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800532 If you disable this option then the kernel will only support
533 standard PC platforms. (which covers the vast majority of
534 systems out there.)
535
536 If you enable this option then you'll be able to select support
537 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800538 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800539 ScaleMP vSMP
540 SGI Ultraviolet
541
542 If you have one of these systems, or if you want to build a
543 generic distribution kernel, say Y here - otherwise say N.
Juerg Haefliger758cd942022-05-25 15:32:02 +0200544endif # X86_64
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800545# This is an alphabetically sorted list of 64 bit extended platforms
546# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800547config X86_NUMACHIP
548 bool "Numascale NumaChip"
549 depends on X86_64
550 depends on X86_EXTENDED_PLATFORM
551 depends on NUMA
552 depends on SMP
553 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700554 depends on PCI_MMCONFIG
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900555 help
Steffen Persvold44b111b52011-12-06 00:07:26 +0800556 Adds support for Numascale NumaChip large-SMP systems. Needed to
557 enable more than ~168 cores.
558 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100559
Ingo Molnar6a485652009-01-27 18:29:13 +0100560config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800561 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100562 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100563 select PARAVIRT
564 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800565 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300566 depends on SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900567 help
Ingo Molnar6a485652009-01-27 18:29:13 +0100568 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
569 supposed to run on these EM64T-based machines. Only choose this option
570 if you have one of these machines.
571
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800572config X86_UV
573 bool "SGI Ultraviolet"
574 depends on X86_64
575 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500576 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800577 depends on EFI
Ingo Molnarc2209ea2021-04-20 09:47:42 +0200578 depends on KEXEC_CORE
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700579 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200580 depends on PCI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900581 help
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800582 This option is needed in order to support SGI Ultraviolet systems.
583 If you don't have one of these, you should say N here.
584
585# Following is an alphabetically sorted list of 32 bit extended platforms
586# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100587
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000588config X86_GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100589 bool "Goldfish (Virtual Platform)"
590 depends on X86_EXTENDED_PLATFORM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900591 help
Juerg Haefliger758cd942022-05-25 15:32:02 +0200592 Enable support for the Goldfish virtual platform used primarily
593 for Android development. Unless you are building for the Android
594 Goldfish emulator say N here.
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000595
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800596config X86_INTEL_CE
597 bool "CE4100 TV platform"
598 depends on PCI
599 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800600 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800601 depends on X86_32
602 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800603 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100604 select OF
605 select OF_EARLY_FLATTREE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900606 help
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800607 Select for the Intel CE media processor (CE4100) SOC.
608 This option compiles in support for the CE4100 SOC for settop
609 boxes and media devices.
610
David Cohen4cb9b002013-12-16 17:37:26 -0800611config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100612 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100613 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800614 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000615 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200616 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000617 depends on X86_IO_APIC
David Cohen4cb9b002013-12-16 17:37:26 -0800618 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000619 select DW_APB_TIMER
Mika Westerberg54b34aa2020-04-16 11:15:33 +0300620 select INTEL_SCU_PCI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900621 help
David Cohen4cb9b002013-12-16 17:37:26 -0800622 Select to build a kernel capable of supporting Intel MID (Mobile
623 Internet Device) platform systems which do not have the PCI legacy
624 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000625
David Cohen4cb9b002013-12-16 17:37:26 -0800626 Intel MID platforms are based on an Intel processor and chipset which
627 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100628
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000629config X86_INTEL_QUARK
630 bool "Intel Quark platform support"
631 depends on X86_32
632 depends on X86_EXTENDED_PLATFORM
633 depends on X86_PLATFORM_DEVICES
634 depends on X86_TSC
635 depends on PCI
636 depends on PCI_GOANY
637 depends on X86_IO_APIC
638 select IOSF_MBI
639 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200640 select COMMON_CLK
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900641 help
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000642 Select to include support for Quark X1000 SoC.
643 Say Y here if you have a Quark based system such as the Arduino
644 compatible Intel Galileo.
645
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000646config X86_INTEL_LPSS
647 bool "Intel Low Power Subsystem Support"
Sinan Kaya5962dd22019-01-02 18:10:37 +0000648 depends on X86 && ACPI && PCI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000649 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300650 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100651 select IOSF_MBI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900652 help
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000653 Select to build support for Intel Low Power Subsystem such as
654 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300655 things like clock tree (common clock framework) and pincontrol
656 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000657
Ken Xue92082a82015-02-06 08:27:51 +0800658config X86_AMD_PLATFORM_DEVICE
659 bool "AMD ACPI2Platform devices support"
660 depends on ACPI
661 select COMMON_CLK
662 select PINCTRL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900663 help
Ken Xue92082a82015-02-06 08:27:51 +0800664 Select to interpret AMD specific ACPI device to platform device
665 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
666 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
667 implemented under PINCTRL subsystem.
668
David E. Boxced3ce72014-09-17 22:13:50 -0700669config IOSF_MBI
670 tristate "Intel SoC IOSF Sideband support for SoC platforms"
671 depends on PCI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900672 help
David E. Boxced3ce72014-09-17 22:13:50 -0700673 This option enables sideband register access support for Intel SoC
674 platforms. On these platforms the IOSF sideband is used in lieu of
675 MSR's for some register accesses, mostly but not limited to thermal
676 and power. Drivers may query the availability of this device to
677 determine if they need the sideband in order to work on these
678 platforms. The sideband is available on the following SoC products.
679 This list is not meant to be exclusive.
680 - BayTrail
681 - Braswell
682 - Quark
683
684 You should say Y if you are running a kernel on one of these SoC's.
685
David E. Boxed2226b2014-09-17 22:13:51 -0700686config IOSF_MBI_DEBUG
687 bool "Enable IOSF sideband access through debugfs"
688 depends on IOSF_MBI && DEBUG_FS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900689 help
David E. Boxed2226b2014-09-17 22:13:51 -0700690 Select this option to expose the IOSF sideband access registers (MCR,
691 MDR, MCRX) through debugfs to write and read register information from
692 different units on the SoC. This is most useful for obtaining device
693 state information for debug and analysis. As this is a general access
694 mechanism, users of this option would have specific knowledge of the
695 device they want to access.
696
697 If you don't require the option or are in doubt, say N.
698
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800699config X86_RDC321X
700 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100701 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800702 depends on X86_EXTENDED_PLATFORM
703 select M486
704 select X86_REBOOTFIXUPS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900705 help
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800706 This option is needed for RDC R-321x system-on-chip, also known
707 as R-8610-(G).
708 If you don't have one of these chips, you should say N here.
709
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100710config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100711 bool "Support non-standard 32-bit SMP architectures"
712 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800713 depends on X86_EXTENDED_PLATFORM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900714 help
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800715 This option compiles in the bigsmp and STA2X11 default
716 subarchitectures. It is intended for a generic binary
717 kernel. If you select them all, kernel will probe it one by
718 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700719
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800720# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700721
Linus Torvaldsd949f362009-09-26 09:35:07 -0700722config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100723 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700724 # MCE code calls memory_failure():
725 depends on X86_MCE
726 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700727 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
728 depends on X86_64 || !SPARSEMEM
729 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700730
Alessandro Rubini83125a32012-04-04 19:40:21 +0200731config STA2X11
732 bool "STA2X11 Companion Chip Support"
733 depends on X86_32_NON_STANDARD && PCI
Alessandro Rubini83125a32012-04-04 19:40:21 +0200734 select SWIOTLB
735 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200736 select GPIOLIB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900737 help
Alessandro Rubini83125a32012-04-04 19:40:21 +0200738 This adds support for boards based on the STA2X11 IO-Hub,
739 a.k.a. "ConneXt". The chip is used in place of the standard
740 PC chipset, so all "standard" peripherals are missing. If this
741 option is selected the kernel will still be able to boot on
742 standard PC machines.
743
Shérab82148d12010-09-25 06:06:57 +0200744config X86_32_IRIS
745 tristate "Eurobraille/Iris poweroff module"
746 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900747 help
Shérab82148d12010-09-25 06:06:57 +0200748 The Iris machines from EuroBraille do not have APM or ACPI support
749 to shut themselves down properly. A special I/O sequence is
750 needed to do so, which is what this module does at
751 kernel shutdown.
752
753 This is only for Iris machines from EuroBraille.
754
755 If unused, say N.
756
Ingo Molnarae1e9132008-11-11 09:05:16 +0100757config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100758 def_bool y
759 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800760 depends on X86
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900761 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100762 Calculate simpler /proc/<PID>/wchan values. If this option
763 is disabled then wchan values will recurse back to the
764 caller function. This provides more accurate wchan values,
765 at the expense of slightly more scheduling overhead.
766
767 If in doubt, say "Y".
768
Borislav Petkov6276a072013-03-04 21:20:21 +0100769menuconfig HYPERVISOR_GUEST
770 bool "Linux guest support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900771 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100772 Say Y here to enable options for running Linux under various hyper-
773 visors. This option enables basic hypervisor detection and platform
774 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100775
Borislav Petkov6276a072013-03-04 21:20:21 +0100776 If you say N, all options in this submenu will be skipped and
777 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100778
Borislav Petkov6276a072013-03-04 21:20:21 +0100779if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100780
Eduardo Pereira Habkoste61bd94a2008-01-30 13:33:32 +0100781config PARAVIRT
782 bool "Enable paravirtualization code"
Juergen Grossa0e2bf72021-03-11 15:23:09 +0100783 depends on HAVE_STATIC_CALL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900784 help
Eduardo Pereira Habkoste61bd94a2008-01-30 13:33:32 +0100785 This changes the kernel so it can modify itself when it is run
786 under a hypervisor, potentially improving performance significantly
787 over full virtualization. However, when run without a hypervisor
788 the kernel is theoretically slower and slightly larger.
789
Juergen Grossc00a2802018-08-28 09:40:21 +0200790config PARAVIRT_XXL
791 bool
792
Borislav Petkov6276a072013-03-04 21:20:21 +0100793config PARAVIRT_DEBUG
794 bool "paravirt-ops debugging"
795 depends on PARAVIRT && DEBUG_KERNEL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900796 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100797 Enable to debug paravirt_ops internals. Specifically, BUG if
798 a paravirt_op is missing when it is called.
799
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700800config PARAVIRT_SPINLOCKS
801 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700802 depends on PARAVIRT && SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900803 help
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700804 Paravirtualized spinlocks allow a pvops backend to replace the
805 spinlock implementation with something virtualization-friendly
806 (for example, block the virtual CPU rather than spinning).
807
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530808 It has a minimal impact on native kernels and gives a nice performance
809 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700810
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530811 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700812
Zhao Yakuiecca25022019-04-30 11:45:23 +0800813config X86_HV_CALLBACK_VECTOR
814 def_bool n
815
Borislav Petkov6276a072013-03-04 21:20:21 +0100816source "arch/x86/xen/Kconfig"
817
818config KVM_GUEST
819 bool "KVM Guest support (including kvmclock)"
820 depends on PARAVIRT
821 select PARAVIRT_CLOCK
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300822 select ARCH_CPUIDLE_HALTPOLL
Vitaly Kuznetsovb1d40572020-05-25 16:41:23 +0200823 select X86_HV_CALLBACK_VECTOR
Borislav Petkov6276a072013-03-04 21:20:21 +0100824 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900825 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100826 This option enables various optimizations for running under the KVM
827 hypervisor. It includes a paravirtualized clock, so that instead
828 of relying on a PIT (or probably other) emulation by the
829 underlying device model, the host provides the guest with
830 timing infrastructure such as time of day, and system time
831
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300832config ARCH_CPUIDLE_HALTPOLL
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100833 def_bool n
834 prompt "Disable host haltpoll when loading haltpoll driver"
835 help
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300836 If virtualized under KVM, disable host haltpoll.
837
Maran Wilson77336072018-12-10 11:07:28 -0800838config PVH
839 bool "Support for running PVH guests"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900840 help
Maran Wilson77336072018-12-10 11:07:28 -0800841 This option enables the PVH entry point for guest virtual machines
842 as specified in the x86/HVM direct boot ABI.
843
Borislav Petkov6276a072013-03-04 21:20:21 +0100844config PARAVIRT_TIME_ACCOUNTING
845 bool "Paravirtual steal time accounting"
846 depends on PARAVIRT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900847 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100848 Select this option to enable fine granularity task steal time
849 accounting. Time spent executing other tasks in parallel with
850 the current vCPU is discounted from the vCPU power. To account for
851 that, there can be a small performance impact.
852
853 If in doubt, say N here.
854
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200855config PARAVIRT_CLOCK
856 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200857
Jan Kiszka4a362602017-11-27 09:11:46 +0100858config JAILHOUSE_GUEST
859 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100860 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100861 select X86_PM_TIMER
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900862 help
Jan Kiszka4a362602017-11-27 09:11:46 +0100863 This option allows to run Linux as guest in a Jailhouse non-root
864 cell. You can leave this option disabled if you only want to start
865 Jailhouse and run Linux afterwards in the root cell.
866
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800867config ACRN_GUEST
868 bool "ACRN Guest support"
869 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800870 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800871 help
872 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
873 a flexible, lightweight reference open-source hypervisor, built with
874 real-time and safety-criticality in mind. It is built for embedded
875 IOT with small footprint and real-time features. More details can be
876 found in https://projectacrn.org/.
877
Kuppuswamy Sathyanarayanan59bd54a2022-04-06 02:29:10 +0300878config INTEL_TDX_GUEST
879 bool "Intel TDX (Trust Domain Extensions) - Guest Support"
880 depends on X86_64 && CPU_SUP_INTEL
881 depends on X86_X2APIC
Kirill A. Shutemov75d090f2023-06-06 17:26:37 +0300882 depends on EFI_STUB
Kirill A. Shutemov41394e32022-04-06 02:29:13 +0300883 select ARCH_HAS_CC_PLATFORM
Kirill A. Shutemov968b4932022-04-06 02:29:36 +0300884 select X86_MEM_ENCRYPT
Sean Christopherson77a512e2022-04-06 02:29:32 +0300885 select X86_MCE
Kirill A. Shutemov75d090f2023-06-06 17:26:37 +0300886 select UNACCEPTED_MEMORY
Kuppuswamy Sathyanarayanan59bd54a2022-04-06 02:29:10 +0300887 help
888 Support running as a guest under Intel TDX. Without this support,
889 the guest kernel can not boot or run under TDX.
890 TDX includes memory encryption and integrity capabilities
891 which protect the confidentiality and integrity of guest
892 memory contents and CPU state. TDX guests are protected from
893 some attacks from the VMM.
894
Juerg Haefliger758cd942022-05-25 15:32:02 +0200895endif # HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400896
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100897source "arch/x86/Kconfig.cpu"
898
899config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100900 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100901 prompt "HPET Timer Support" if X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900902 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100903 Use the IA-PC HPET (High Precision Event Timer) to manage
904 time in preference to the PIT and RTC, if a HPET is
905 present.
906 HPET is the next generation timer replacing legacy 8254s.
907 The HPET provides a stable time base on SMP
908 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200909 as it is off-chip. The interface used is documented
910 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100911
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100912 You can safely choose Y here. However, HPET will only be
913 activated if the platform and the BIOS support this feature.
914 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100915
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100916 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100917
918config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100919 def_bool y
Anand K Mistry3228e1d2021-02-04 18:32:32 +1100920 depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100921
David Rientjes6a108a12011-01-20 14:44:16 -0800922# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100923# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700924config DMI
925 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800926 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800927 bool "Enable DMI scanning" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900928 help
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700929 Enabled scanning of DMI to identify machine quirks. Say Y
930 here unless you have verified that your setup is not
931 affected by entries in the DMI blacklist. Required by PNP
932 BIOS code.
933
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100934config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700935 bool "Old AMD GART IOMMU support"
Christoph Hellwig2f9237d2020-07-08 09:30:00 +0200936 select DMA_OPS
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200937 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100938 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200939 depends on X86_64 && PCI && AMD_NB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900940 help
Ingo Molnarced3c422013-10-06 11:45:20 +0200941 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
942 GART based hardware IOMMUs.
943
944 The GART supports full DMA access for devices with 32-bit access
945 limitations, on systems with more than 3 GB. This is usually needed
946 for USB, sound, many IDE/SATA chipsets and some other devices.
947
948 Newer systems typically have a modern AMD IOMMU, supported via
949 the CONFIG_AMD_IOMMU=y config option.
950
951 In normal configurations this driver is only active when needed:
952 there's more than 3 GB of memory and the system contains a
953 32-bit limited device.
954
955 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100956
Michal Suchanek8b766b02022-02-25 21:51:34 +0100957config BOOT_VESA_SUPPORT
958 bool
959 help
960 If true, at least one selected framebuffer driver can take advantage
961 of VESA video modes set at an early boot stage via the vga= parameter.
962
Mike Travis1184dc22008-05-12 21:21:12 +0200963config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200964 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700965 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800966 select CPUMASK_OFFSTACK
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900967 help
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200968 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200969 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100970
Ingo Molnaraec64872018-02-10 12:36:29 +0100971#
972# The maximum number of CPUs supported:
973#
974# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
975# and which can be configured interactively in the
976# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
977#
978# The ranges are different on 32-bit and 64-bit kernels, depending on
979# hardware capabilities and scalability features of the kernel.
980#
981# ( If MAXSMP is enabled we just use the highest possible value and disable
982# interactive configuration. )
983#
984
985config NR_CPUS_RANGE_BEGIN
986 int
987 default NR_CPUS_RANGE_END if MAXSMP
988 default 1 if !SMP
989 default 2
990
991config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800992 int
993 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100994 default 64 if SMP && X86_BIGSMP
995 default 8 if SMP && !X86_BIGSMP
996 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800997
Ingo Molnaraec64872018-02-10 12:36:29 +0100998config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800999 int
1000 depends on X86_64
Scott Wood1edae1a2019-10-12 02:00:54 -05001001 default 8192 if SMP && CPUMASK_OFFSTACK
1002 default 512 if SMP && !CPUMASK_OFFSTACK
Ingo Molnaraec64872018-02-10 12:36:29 +01001003 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001004
Ingo Molnaraec64872018-02-10 12:36:29 +01001005config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001006 int
1007 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +01001008 default 32 if X86_BIGSMP
1009 default 8 if SMP
1010 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001011
Ingo Molnaraec64872018-02-10 12:36:29 +01001012config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001013 int
1014 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +01001015 default 8192 if MAXSMP
1016 default 64 if SMP
1017 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001018
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001019config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -08001020 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +01001021 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1022 default NR_CPUS_DEFAULT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001023 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001024 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -05001025 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +03001026 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001027 minimum value which makes sense is 2.
1028
Ingo Molnaraec64872018-02-10 12:36:29 +01001029 This is purely to save memory: each supported CPU adds about 8KB
1030 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001031
Tim Chen66558b72021-09-24 20:51:04 +12001032config SCHED_CLUSTER
1033 bool "Cluster scheduler support"
1034 depends on SMP
1035 default y
1036 help
1037 Cluster scheduler support improves the CPU scheduler's decision
1038 making when dealing with machines that have clusters of CPUs.
1039 Cluster usually means a couple of CPUs which are placed closely
1040 by sharing mid-level caches, last-level cache tags or internal
1041 busses.
1042
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001043config SCHED_SMT
Thomas Gleixnerdbe73362018-11-25 19:33:37 +01001044 def_bool y if SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001045
1046config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001047 def_bool y
1048 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001049 depends on SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001050 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001051 Multi-core scheduler support improves the CPU scheduler's decision
1052 making when dealing with multi-core CPU chips at a cost of slightly
1053 increased overhead in some places. If unsure say N here.
1054
Tim Chende966cf2016-11-29 10:43:27 -08001055config SCHED_MC_PRIO
1056 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001057 depends on SCHED_MC && CPU_SUP_INTEL
1058 select X86_INTEL_PSTATE
1059 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001060 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001061 help
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001062 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1063 core ordering determined at manufacturing time, which allows
1064 certain cores to reach higher turbo frequencies (when running
1065 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001066
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001067 Enabling this kernel feature teaches the scheduler about
1068 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1069 scheduler's CPU selection logic accordingly, so that higher
1070 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001071
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001072 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001073
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001074 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001075
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001076config UP_LATE_INIT
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001077 def_bool y
1078 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001079
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001080config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001081 bool "Local APIC support on uniprocessors" if !PCI_MSI
1082 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001083 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001084 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001085 A local APIC (Advanced Programmable Interrupt Controller) is an
1086 integrated interrupt controller in the CPU. If you have a single-CPU
1087 system which has a processor with a local APIC, you can say Y here to
1088 enable and use it. If you say Y here even though your machine doesn't
1089 have a local APIC, then the kernel will still run with no slowdown at
1090 all. The local APIC supports CPU-generated self-interrupts (timer,
1091 performance counters), and the NMI watchdog which detects hard
1092 lockups.
1093
1094config X86_UP_IOAPIC
1095 bool "IO-APIC support on uniprocessors"
1096 depends on X86_UP_APIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001097 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001098 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1099 SMP-capable replacement for PC-style interrupt controllers. Most
1100 SMP systems and many recent uniprocessor systems have one.
1101
1102 If you have a single-CPU system with an IO-APIC, you can say Y here
1103 to use it. If you say Y here even though your machine doesn't have
1104 an IO-APIC, then the kernel will still run with no slowdown at all.
1105
1106config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001107 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001108 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001109 select IRQ_DOMAIN_HIERARCHY
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001110
1111config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001112 def_bool y
1113 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001114
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001115config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1116 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001117 depends on X86_IO_APIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001118 help
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001119 This option enables a workaround that fixes a source of
1120 spurious interrupts. This is recommended when threaded
1121 interrupt handling is used on systems where the generation of
1122 superfluous "boot interrupts" cannot be disabled.
1123
1124 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1125 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1126 kernel does during interrupt handling). On chipsets where this
1127 boot IRQ generation cannot be disabled, this workaround keeps
1128 the original IRQ line masked so that only the equivalent "boot
1129 IRQ" is delivered to the CPUs. The workaround also tells the
1130 kernel to set up the IRQ handler on the boot IRQ line. In this
1131 way only one interrupt is delivered to the kernel. Otherwise
1132 the spurious second interrupt may cause the kernel to bring
1133 down (vital) interrupt lines.
1134
1135 Only affects "broken" chipsets. Interrupt sharing may be
1136 increased on these systems.
1137
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001138config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001139 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001140 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001141 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001142 help
Andi Kleenbab9bc62009-07-09 00:31:38 +02001143 Machine Check support allows the processor to notify the
1144 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001145 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001146 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001147
Tony Luck5de97c92017-03-27 11:33:03 +02001148config X86_MCELOG_LEGACY
1149 bool "Support for deprecated /dev/mcelog character device"
1150 depends on X86_MCE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001151 help
Tony Luck5de97c92017-03-27 11:33:03 +02001152 Enable support for /dev/mcelog which is needed by the old mcelog
1153 userspace logging daemon. Consider switching to the new generation
1154 rasdaemon solution.
1155
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001156config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001157 def_bool y
1158 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001159 depends on X86_MCE && X86_LOCAL_APIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001160 help
Juerg Haefliger758cd942022-05-25 15:32:02 +02001161 Additional support for intel specific MCE features such as
1162 the thermal monitor.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001163
1164config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001165 def_bool y
1166 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001167 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001168 help
Juerg Haefliger758cd942022-05-25 15:32:02 +02001169 Additional support for AMD specific MCE features such as
1170 the DRAM Error Threshold.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001171
Andi Kleen4efc0672009-04-28 19:07:31 +02001172config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001173 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001174 depends on X86_32 && X86_MCE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001175 help
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001176 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001177 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001178 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001179
Andi Kleenb2762682009-02-12 13:49:31 +01001180config X86_MCE_THRESHOLD
1181 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001182 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001183
Andi Kleenea149b32009-04-29 19:31:00 +02001184config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001185 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001186 tristate "Machine check injector support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001187 help
Andi Kleenea149b32009-04-29 19:31:00 +02001188 Provide support for injecting machine checks for testing purposes.
1189 If you don't know what a machine check is and you don't do kernel
1190 QA it is safe to say n.
1191
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001192source "arch/x86/events/Kconfig"
Kan Liange633c65a2016-03-20 01:33:36 -07001193
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001194config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001195 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001196 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001197 help
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001198 This option allows user programs to put the CPU into V8086
1199 mode, which is an 80286-era approximation of 16-bit real mode.
1200
1201 Some very old versions of X and/or vbetool require this option
1202 for user mode setting. Similarly, DOSEMU will use it if
1203 available to accelerate real mode DOS programs. However, any
1204 recent version of DOSEMU, X, or vbetool should be fully
1205 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001206 fall back to software emulation. Nevertheless, if you are using
1207 a 16-bit DOS program where 16-bit performance matters, vm86
1208 mode might be faster than emulation and you might want to
1209 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001210
Ingo Molnar1e642812015-09-05 08:58:10 +02001211 Note that any app that works on a 64-bit kernel is unlikely to
1212 need this option, as 64-bit kernels don't, and can't, support
1213 V8086 mode. This option is also unrelated to 16-bit protected
1214 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001215
Ingo Molnar1e642812015-09-05 08:58:10 +02001216 Enabling this option increases the complexity of the kernel
1217 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001218
Ingo Molnar1e642812015-09-05 08:58:10 +02001219 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001220
1221config VM86
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001222 bool
1223 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001224
1225config X86_16BIT
1226 bool "Enable support for 16-bit segments" if EXPERT
1227 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001228 depends on MODIFY_LDT_SYSCALL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001229 help
H. Peter Anvin34273f42014-05-04 10:36:22 -07001230 This option is required by programs like Wine to run 16-bit
1231 protected mode legacy code on x86 processors. Disabling
1232 this option saves about 300 bytes on i386, or around 6K text
1233 plus 16K runtime memory on x86-64,
1234
1235config X86_ESPFIX32
1236 def_bool y
1237 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001238
H. Peter Anvin197725d2014-05-04 10:00:49 -07001239config X86_ESPFIX64
1240 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001241 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001242
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001243config X86_VSYSCALL_EMULATION
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001244 bool "Enable vsyscall emulation" if EXPERT
1245 default y
1246 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001247 help
Juerg Haefliger758cd942022-05-25 15:32:02 +02001248 This enables emulation of the legacy vsyscall page. Disabling
1249 it is roughly equivalent to booting with vsyscall=none, except
1250 that it will also disable the helpful warning if a program
1251 tries to use a vsyscall. With this option set to N, offending
1252 programs will just segfault, citing addresses of the form
1253 0xffffffffff600?00.
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001254
Juerg Haefliger758cd942022-05-25 15:32:02 +02001255 This option is required by many programs built before 2013, and
1256 care should be used even with newer programs if set to N.
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001257
Juerg Haefliger758cd942022-05-25 15:32:02 +02001258 Disabling this option saves about 7K of kernel size and
1259 possibly 4K of additional runtime pagetable memory.
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001260
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001261config X86_IOPL_IOPERM
1262 bool "IOPERM and IOPL Emulation"
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001263 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001264 help
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001265 This enables the ioperm() and iopl() syscalls which are necessary
1266 for legacy applications.
1267
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001268 Legacy IOPL support is an overbroad mechanism which allows user
1269 space aside of accessing all 65536 I/O ports also to disable
1270 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1271 capabilities and permission from potentially active security
1272 modules.
1273
1274 The emulation restricts the functionality of the syscall to
1275 only allowing the full range I/O port access, but prevents the
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001276 ability to disable interrupts from user space which would be
1277 granted if the hardware IOPL mechanism would be used.
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001278
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001279config TOSHIBA
1280 tristate "Toshiba Laptop support"
1281 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001282 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001283 This adds a driver to safely access the System Management Mode of
1284 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1285 not work on models with a Phoenix BIOS. The System Management Mode
1286 is used to set the BIOS and power saving options on Toshiba portables.
1287
1288 For information on utilities to make use of this driver see the
1289 Toshiba Linux utilities web site at:
1290 <http://www.buzzard.org.uk/toshiba/>.
1291
1292 Say Y if you intend to run this kernel on a Toshiba portable.
1293 Say N otherwise.
1294
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001295config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001296 bool "Enable X86 board specific fixups for reboot"
1297 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001298 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001299 This enables chipset and/or board specific fixups to be done
1300 in order to get reboot to work correctly. This is only needed on
1301 some combinations of hardware and BIOS. The symptom, for which
1302 this config is intended, is when reboot ends with a stalled/hung
1303 system.
1304
1305 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001306 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001307
1308 Say Y if you want to enable the fixup. Currently, it's safe to
1309 enable this option even if you don't need it.
1310 Say N otherwise.
1311
1312config MICROCODE
Thomas Gleixnere6bcfdd2023-08-10 20:37:29 +02001313 def_bool y
Borislav Petkov80030e32013-10-13 18:36:29 +02001314 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Peter Oruba80cc9f12008-07-28 18:44:22 +02001315
Borislav Petkova77a94f2022-05-25 18:12:30 +02001316config MICROCODE_LATE_LOADING
1317 bool "Late microcode loading (DANGEROUS)"
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001318 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001319 depends on MICROCODE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001320 help
Borislav Petkova77a94f2022-05-25 18:12:30 +02001321 Loading microcode late, when the system is up and executing instructions
1322 is a tricky business and should be avoided if possible. Just the sequence
1323 of synchronizing all cores and SMT threads is one fragile dance which does
1324 not guarantee that cores might not softlock after the loading. Therefore,
1325 use this at your own risk. Late loading taints the kernel too.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001326
1327config X86_MSR
1328 tristate "/dev/cpu/*/msr - Model-specific register support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001329 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001330 This device gives privileged processes access to the x86
1331 Model-Specific Registers (MSRs). It is a character device with
1332 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1333 MSR accesses are directed to a specific CPU on multi-processor
1334 systems.
1335
1336config X86_CPUID
1337 tristate "/dev/cpu/*/cpuid - CPU information support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001338 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001339 This device gives processes access to the x86 CPUID instruction to
1340 be executed on a specific processor. It is a character device
1341 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1342 /dev/cpu/31/cpuid.
1343
1344choice
1345 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001346 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001347 depends on X86_32
1348
1349config NOHIGHMEM
1350 bool "off"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001351 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001352 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1353 However, the address space of 32-bit x86 processors is only 4
1354 Gigabytes large. That means that, if you have a large amount of
1355 physical memory, not all of it can be "permanently mapped" by the
1356 kernel. The physical memory that's not permanently mapped is called
1357 "high memory".
1358
1359 If you are compiling a kernel which will never run on a machine with
1360 more than 1 Gigabyte total physical RAM, answer "off" here (default
1361 choice and suitable for most users). This will result in a "3GB/1GB"
1362 split: 3GB are mapped so that each process sees a 3GB virtual memory
1363 space and the remaining part of the 4GB virtual memory space is used
1364 by the kernel to permanently map as much physical memory as
1365 possible.
1366
1367 If the machine has between 1 and 4 Gigabytes physical RAM, then
1368 answer "4GB" here.
1369
1370 If more than 4 Gigabytes is used then answer "64GB" here. This
1371 selection turns Intel PAE (Physical Address Extension) mode on.
1372 PAE implements 3-level paging on IA32 processors. PAE is fully
1373 supported by Linux, PAE mode is implemented on all recent Intel
1374 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1375 then the kernel will not boot on CPUs that don't support PAE!
1376
1377 The actual amount of total physical memory will either be
1378 auto detected or can be forced by using a kernel command line option
1379 such as "mem=256M". (Try "man bootparam" or see the documentation of
1380 your boot loader (lilo or loadlin) about how to pass options to the
1381 kernel at boot time.)
1382
1383 If unsure, say "off".
1384
1385config HIGHMEM4G
1386 bool "4GB"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001387 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001388 Select this if you have a 32-bit processor and between 1 and 4
1389 gigabytes of physical RAM.
1390
1391config HIGHMEM64G
1392 bool "64GB"
Lukas Bulwahn225bac22021-08-03 13:35:25 +02001393 depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001394 select X86_PAE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001395 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001396 Select this if you have a 32-bit processor and more than 4
1397 gigabytes of physical RAM.
1398
1399endchoice
1400
1401choice
David Rientjes6a108a12011-01-20 14:44:16 -08001402 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001403 default VMSPLIT_3G
1404 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001405 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001406 Select the desired split between kernel and user memory.
1407
1408 If the address range available to the kernel is less than the
1409 physical memory installed, the remaining memory will be available
1410 as "high memory". Accessing high memory is a little more costly
1411 than low memory, as it needs to be mapped into the kernel first.
1412 Note that increasing the kernel address space limits the range
1413 available to user programs, making the address space there
1414 tighter. Selecting anything other than the default 3G/1G split
1415 will also likely make your kernel incompatible with binary-only
1416 kernel modules.
1417
1418 If you are not absolutely sure what you are doing, leave this
1419 option alone!
1420
1421 config VMSPLIT_3G
1422 bool "3G/1G user/kernel split"
1423 config VMSPLIT_3G_OPT
1424 depends on !X86_PAE
1425 bool "3G/1G user/kernel split (for full 1G low memory)"
1426 config VMSPLIT_2G
1427 bool "2G/2G user/kernel split"
1428 config VMSPLIT_2G_OPT
1429 depends on !X86_PAE
1430 bool "2G/2G user/kernel split (for full 2G low memory)"
1431 config VMSPLIT_1G
1432 bool "1G/3G user/kernel split"
1433endchoice
1434
1435config PAGE_OFFSET
1436 hex
1437 default 0xB0000000 if VMSPLIT_3G_OPT
1438 default 0x80000000 if VMSPLIT_2G
1439 default 0x78000000 if VMSPLIT_2G_OPT
1440 default 0x40000000 if VMSPLIT_1G
1441 default 0xC0000000
1442 depends on X86_32
1443
1444config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001445 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001446 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001447
1448config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001449 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001450 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001451 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001452 select SWIOTLB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001453 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001454 PAE is required for NX support, and furthermore enables
1455 larger swapspace support for non-overcommit purposes. It
1456 has the cost of more pagetable lookup overhead, and also
1457 consumes more pagetable space per process.
1458
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001459config X86_5LEVEL
1460 bool "Enable 5-level page tables support"
Kirill A. Shutemov18ec1ea2019-09-13 12:54:52 +03001461 default y
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001462 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001463 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001464 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001465 help
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001466 5-level paging enables access to larger address space:
Randy Dunlap54628de2023-01-24 10:17:53 -08001467 up to 128 PiB of virtual address space and 4 PiB of
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001468 physical address space.
1469
1470 It will be supported by future Intel CPUs.
1471
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001472 A kernel with the option enabled can be booted on machines that
1473 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001474
Jonathan Corbetff61f072023-03-14 17:06:44 -06001475 See Documentation/arch/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001476 information.
1477
1478 Say N if unsure.
1479
Ingo Molnar10971ab2015-03-05 08:18:23 +01001480config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001481 def_bool y
Vlastimil Babka2e1da132019-08-07 15:02:58 +02001482 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001483 help
Ingo Molnar10971ab2015-03-05 08:18:23 +01001484 Certain kernel features effectively disable kernel
1485 linear 1 GB mappings (even if the CPU otherwise
1486 supports them), so don't confuse the user by printing
1487 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001488
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001489config X86_CPA_STATISTICS
1490 bool "Enable statistic for Change Page Attribute"
1491 depends on DEBUG_FS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001492 help
Ingo Molnarb75baaf2019-11-20 15:57:04 +01001493 Expose statistics about the Change Page Attribute mechanism, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001494 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001495 page mappings when mapping protections are changed.
1496
Kirill A. Shutemov20f07a02021-12-06 16:55:05 +03001497config X86_MEM_ENCRYPT
1498 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1499 select DYNAMIC_PHYSICAL_MASK
Kirill A. Shutemov20f07a02021-12-06 16:55:05 +03001500 def_bool n
1501
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001502config AMD_MEM_ENCRYPT
1503 bool "AMD Secure Memory Encryption (SME) support"
1504 depends on X86_64 && CPU_SUP_AMD
Tom Lendacky6c321172023-06-06 09:51:26 -05001505 depends on EFI_STUB
David Rientjes82fef0a2020-04-14 17:05:01 -07001506 select DMA_COHERENT_POOL
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001507 select ARCH_USE_MEMREMAP_PROT
Joerg Roedel597cfe482020-09-07 15:15:24 +02001508 select INSTRUCTION_DECODER
Tom Lendackyaa5a4612021-09-08 17:58:34 -05001509 select ARCH_HAS_CC_PLATFORM
Kirill A. Shutemov20f07a02021-12-06 16:55:05 +03001510 select X86_MEM_ENCRYPT
Tom Lendacky6c321172023-06-06 09:51:26 -05001511 select UNACCEPTED_MEMORY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001512 help
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001513 Say yes to enable support for the encryption of system memory.
1514 This requires an AMD processor that supports Secure Memory
1515 Encryption (SME).
1516
1517config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1518 bool "Activate AMD Secure Memory Encryption (SME) by default"
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001519 depends on AMD_MEM_ENCRYPT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001520 help
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001521 Say yes to have system memory encrypted by default if running on
1522 an AMD processor that supports Secure Memory Encryption (SME).
1523
1524 If set to Y, then the encryption of system memory can be
1525 deactivated with the mem_encrypt=off command line option.
1526
1527 If set to N, then the encryption of system memory can be
1528 activated with the mem_encrypt=on command line option.
1529
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001530# Common NUMA Features
1531config NUMA
Randy Dunlape133f6e2019-12-03 16:06:47 -08001532 bool "NUMA Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001533 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001534 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1535 default y if X86_BIGSMP
Kefeng Wang7ecd19c2022-01-19 18:07:41 -08001536 select USE_PERCPU_NUMA_NODE_ID
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001537 help
Randy Dunlape133f6e2019-12-03 16:06:47 -08001538 Enable NUMA (Non-Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001539
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001540 The kernel will try to allocate memory used by a CPU on the
1541 local memory controller of the CPU and add some more
1542 NUMA awareness to the kernel.
1543
Ingo Molnarc280ea52008-11-08 13:29:45 +01001544 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001545 (or later), AMD Opteron, or EM64T NUMA.
1546
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001547 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001548 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001549
1550 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001551
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001552config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001553 def_bool y
1554 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001555 depends on X86_64 && NUMA && PCI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001556 help
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001557 Enable AMD NUMA node topology detection. You should say Y here if
1558 you have a multi processor AMD system. This uses an old method to
1559 read the NUMA configuration directly from the builtin Northbridge
1560 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1561 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001562
1563config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001564 def_bool y
1565 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001566 depends on X86_64 && NUMA && ACPI && PCI
1567 select ACPI_NUMA
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001568 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001569 Enable ACPI SRAT based node topology detection.
1570
1571config NUMA_EMU
1572 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001573 depends on NUMA
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001574 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001575 Enable NUMA emulation. A flat machine will be split
1576 into virtual nodes when booted with "numa=fake=N", where N is the
1577 number of nodes. This is only useful for debugging.
1578
1579config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001580 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001581 range 1 10
1582 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001583 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001584 default "3"
Mike Rapoporta9ee6cf2021-06-28 19:43:01 -07001585 depends on NUMA
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001586 help
Mike Travis1184dc22008-05-12 21:21:12 +02001587 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001588 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001589
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001590config ARCH_FLATMEM_ENABLE
1591 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001592 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001593
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001594config ARCH_SPARSEMEM_ENABLE
1595 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001596 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001597 select SPARSEMEM_STATIC if X86_32
1598 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1599
Tejun Heo3b166512011-04-01 11:15:12 +02001600config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001601 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001602
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001603config ARCH_SELECT_MEMORY_MODEL
1604 def_bool y
David Hildenbrand4eda2bc2021-09-29 16:43:21 +02001605 depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001606
1607config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001608 bool "Enable sysfs memory/probe interface"
David Hildenbrand5c11f00b2021-11-05 13:44:39 -07001609 depends on MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001610 help
1611 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001612 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001613 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001614
Tejun Heo3b166512011-04-01 11:15:12 +02001615config ARCH_PROC_KCORE_TEXT
1616 def_bool y
1617 depends on X86_64 && PROC_KCORE
1618
Avi Kivitya29815a2010-01-10 16:28:09 +02001619config ILLEGAL_POINTER_VALUE
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001620 hex
1621 default 0 if X86_32
1622 default 0xdead000000000000 if X86_64
Avi Kivitya29815a2010-01-10 16:28:09 +02001623
Dan Williams7a678322015-08-19 00:34:34 -04001624config X86_PMEM_LEGACY_DEVICE
1625 bool
1626
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001627config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001628 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001629 depends on PHYS_ADDR_T_64BIT
1630 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001631 select X86_PMEM_LEGACY_DEVICE
Dan Williams7b27a862020-02-16 12:01:16 -08001632 select NUMA_KEEP_MEMINFO if NUMA
Dan Williams9f53f9f2015-06-09 15:33:45 -04001633 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001634 help
1635 Treat memory marked using the non-standard e820 type of 12 as used
1636 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1637 The kernel will offer these regions to the 'pmem' driver so
1638 they can be used for persistent storage.
1639
1640 Say Y if unsure.
1641
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001642config HIGHPTE
1643 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001644 depends on HIGHMEM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001645 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001646 The VM uses one page table entry for each page of physical memory.
1647 For systems with a lot of RAM, this can be wasteful of precious
1648 low memory. Setting this option will put user-space page table
1649 entries in high memory.
1650
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001651config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001652 bool "Check for low memory corruption"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001653 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001654 Periodically check for memory corruption in low memory, which
1655 is suspected to be caused by BIOS. Even when enabled in the
1656 configuration, it is disabled at runtime. Enable it by
1657 setting "memory_corruption_check=1" on the kernel command
1658 line. By default it scans the low 64k of memory every 60
1659 seconds; see the memory_corruption_check_size and
1660 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001661 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001662
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001663 When enabled with the default parameters, this option has
1664 almost no overhead, as it reserves a relatively small amount
1665 of memory and scans it infrequently. It both detects corruption
1666 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001667
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001668 It is, however, intended as a diagnostic tool; if repeatable
1669 BIOS-originated corruption always affects the same memory,
1670 you can use memmap= to prevent the kernel from using that
1671 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001672
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001673config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001674 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001675 depends on X86_CHECK_BIOS_CORRUPTION
1676 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001677 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001678 Set whether the default state of memory_corruption_check is
1679 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001680
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001681config MATH_EMULATION
1682 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001683 depends on MODIFY_LDT_SYSCALL
Arnd Bergmann87d60212019-10-01 16:23:35 +02001684 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001685 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001686 Linux can emulate a math coprocessor (used for floating point
1687 operations) if you don't have one. 486DX and Pentium processors have
1688 a math coprocessor built in, 486SX and 386 do not, unless you added
1689 a 487DX or 387, respectively. (The messages during boot time can
1690 give you some hints here ["man dmesg"].) Everyone needs either a
1691 coprocessor or this emulation.
1692
1693 If you don't have a math coprocessor, you need to say Y here; if you
1694 say Y here even though you have a coprocessor, the coprocessor will
1695 be used nevertheless. (This behavior can be changed with the kernel
1696 command line option "no387", which comes handy if your coprocessor
1697 is broken. Try "man bootparam" or see the documentation of your boot
1698 loader (lilo or loadlin) about how to pass options to the kernel at
1699 boot time.) This means that it is a good idea to say Y here if you
1700 intend to use this kernel on different machines.
1701
1702 More information about the internals of the Linux math coprocessor
1703 emulation can be found in <file:arch/x86/math-emu/README>.
1704
1705 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1706 kernel, it won't hurt.
1707
1708config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001709 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001710 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001711 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001712 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1713 the Memory Type Range Registers (MTRRs) may be used to control
1714 processor access to memory ranges. This is most useful if you have
1715 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1716 allows bus write transfers to be combined into a larger transfer
1717 before bursting over the PCI/AGP bus. This can increase performance
1718 of image write operations 2.5 times or more. Saying Y here creates a
1719 /proc/mtrr file which may be used to manipulate your processor's
1720 MTRRs. Typically the X server should use this.
1721
1722 This code has a reasonably generic interface so that similar
1723 control registers on other processors can be easily supported
1724 as well:
1725
1726 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1727 Registers (ARRs) which provide a similar functionality to MTRRs. For
1728 these, the ARRs are used to emulate the MTRRs.
1729 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1730 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1731 write-combining. All of these processors are supported by this code
1732 and it makes sense to say Y here if you have one of them.
1733
1734 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1735 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1736 can lead to all sorts of problems, so it's good to say Y here.
1737
1738 You can safely say Y even if your machine doesn't have MTRRs, you'll
1739 just add about 9 KB to your kernel.
1740
Jonathan Corbetff61f072023-03-14 17:06:44 -06001741 See <file:Documentation/arch/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001742
Yinghai Lu95ffa242008-04-29 03:52:33 -07001743config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001744 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001745 prompt "MTRR cleanup support"
1746 depends on MTRR
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001747 help
Thomas Gleixneraba37282008-07-15 14:48:48 +02001748 Convert MTRR layout from continuous to discrete, so X drivers can
1749 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001750
Thomas Gleixneraba37282008-07-15 14:48:48 +02001751 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001752 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001753 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001754
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001755 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001756
1757config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001758 int "MTRR cleanup enable value (0-1)"
1759 range 0 1
1760 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001761 depends on MTRR_SANITIZER
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001762 help
Yinghai Luf5098d62008-04-29 20:25:58 -07001763 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001764
Yinghai Lu12031a62008-05-02 02:40:22 -07001765config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1766 int "MTRR cleanup spare reg num (0-7)"
1767 range 0 7
1768 default "1"
1769 depends on MTRR_SANITIZER
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001770 help
Yinghai Lu12031a62008-05-02 02:40:22 -07001771 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001772 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001773
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001774config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001775 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001776 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001777 depends on MTRR
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001778 help
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001779 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001780
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001781 PATs are the modern equivalents of MTRRs and are much more
1782 flexible than MTRRs.
1783
1784 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001785 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001786
1787 If unsure, say Y.
1788
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001789config ARCH_USES_PG_UNCACHED
1790 def_bool y
1791 depends on X86_PAT
1792
Babu Mogerb9718802019-11-05 21:25:32 +00001793config X86_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001794 def_bool y
Babu Mogerb9718802019-11-05 21:25:32 +00001795 prompt "User Mode Instruction Prevention" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001796 help
Babu Mogerb9718802019-11-05 21:25:32 +00001797 User Mode Instruction Prevention (UMIP) is a security feature in
1798 some x86 processors. If enabled, a general protection fault is
1799 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1800 executed in user mode. These instructions unnecessarily expose
1801 information about the hardware state.
Ricardo Neri796ebc82017-11-13 22:29:42 -08001802
1803 The vast majority of applications do not use these instructions.
1804 For the very few that do, software emulation is provided in
1805 specific cases in protected and virtual-8086 modes. Emulated
1806 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001807
Peter Zijlstra156ff4a2022-03-08 16:30:17 +01001808config CC_HAS_IBT
1809 # GCC >= 9 and binutils >= 2.29
1810 # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1811 # Clang/LLVM >= 14
Nathan Chancellor262448f2022-03-18 16:07:46 -07001812 # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1813 # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
Peter Zijlstra156ff4a2022-03-08 16:30:17 +01001814 def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
Nathan Chancellor262448f2022-03-18 16:07:46 -07001815 (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
Peter Zijlstra156ff4a2022-03-08 16:30:17 +01001816 $(as-instr,endbr64)
1817
Rick Edgecombe18e66b62023-06-12 17:10:32 -07001818config X86_CET
1819 def_bool n
1820 help
1821 CET features configured (Shadow stack or IBT)
1822
Peter Zijlstra156ff4a2022-03-08 16:30:17 +01001823config X86_KERNEL_IBT
1824 prompt "Indirect Branch Tracking"
Kees Cook4fd5f702022-11-01 10:25:07 -07001825 def_bool y
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -07001826 depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
Nathan Chancellorf6a2c2b2022-03-18 16:07:47 -07001827 # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1828 depends on !LD_IS_LLD || LLD_VERSION >= 140000
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -07001829 select OBJTOOL
Rick Edgecombe18e66b62023-06-12 17:10:32 -07001830 select X86_CET
Peter Zijlstra156ff4a2022-03-08 16:30:17 +01001831 help
1832 Build the kernel with support for Indirect Branch Tracking, a
1833 hardware support course-grain forward-edge Control Flow Integrity
1834 protection. It enforces that all indirect calls must land on
1835 an ENDBR instruction, as such, the compiler will instrument the
1836 code with them to make this happen.
1837
Peter Zijlstraed53a0d2022-03-08 16:30:56 +01001838 In addition to building the kernel with IBT, seal all functions that
Nur Hussein4cdfc112022-04-18 03:24:54 +08001839 are not indirect call targets, avoiding them ever becoming one.
Peter Zijlstraed53a0d2022-03-08 16:30:56 +01001840
1841 This requires LTO like objtool runs and will slow down the build. It
1842 does significantly reduce the number of ENDBR instructions in the
1843 kernel image.
1844
Dave Hansen35e97792016-02-12 13:02:00 -08001845config X86_INTEL_MEMORY_PROTECTION_KEYS
Babu Moger38f3e772020-05-28 11:08:23 -05001846 prompt "Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001847 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001848 # Note: only available in 64-bit mode
Babu Moger38f3e772020-05-28 11:08:23 -05001849 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Ingo Molnar52c8e602016-11-15 10:15:03 +01001850 select ARCH_USES_HIGH_VMA_FLAGS
1851 select ARCH_HAS_PKEYS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001852 help
Dave Hansen284244a2016-02-12 13:02:28 -08001853 Memory Protection Keys provides a mechanism for enforcing
1854 page-based protections, but without requiring modification of the
1855 page tables when an application changes protection domains.
1856
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001857 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001858
1859 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001860
Michal Hockodb616172019-10-23 12:35:50 +02001861choice
1862 prompt "TSX enable mode"
1863 depends on CPU_SUP_INTEL
1864 default X86_INTEL_TSX_MODE_OFF
1865 help
1866 Intel's TSX (Transactional Synchronization Extensions) feature
1867 allows to optimize locking protocols through lock elision which
1868 can lead to a noticeable performance boost.
1869
1870 On the other hand it has been shown that TSX can be exploited
1871 to form side channel attacks (e.g. TAA) and chances are there
1872 will be more of those attacks discovered in the future.
1873
1874 Therefore TSX is not enabled by default (aka tsx=off). An admin
1875 might override this decision by tsx=on the command line parameter.
1876 Even with TSX enabled, the kernel will attempt to enable the best
1877 possible TAA mitigation setting depending on the microcode available
1878 for the particular machine.
1879
1880 This option allows to set the default tsx mode between tsx=on, =off
1881 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1882 details.
1883
1884 Say off if not sure, auto if TSX is in use but it should be used on safe
1885 platforms or on if TSX is in use and the security aspect of tsx is not
1886 relevant.
1887
1888config X86_INTEL_TSX_MODE_OFF
1889 bool "off"
1890 help
1891 TSX is disabled if possible - equals to tsx=off command line parameter.
1892
1893config X86_INTEL_TSX_MODE_ON
1894 bool "on"
1895 help
1896 TSX is always enabled on TSX capable HW - equals the tsx=on command
1897 line parameter.
1898
1899config X86_INTEL_TSX_MODE_AUTO
1900 bool "auto"
1901 help
1902 TSX is enabled on TSX capable HW that is believed to be safe against
1903 side channel attacks- equals the tsx=auto command line parameter.
1904endchoice
1905
Sean Christophersone7e05452020-11-13 00:01:16 +02001906config X86_SGX
1907 bool "Software Guard eXtensions (SGX)"
Daniel Sneddonb8d1d162022-08-16 16:19:42 -07001908 depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
Sean Christophersone7e05452020-11-13 00:01:16 +02001909 depends on CRYPTO=y
1910 depends on CRYPTO_SHA256=y
Sean Christophersone7e05452020-11-13 00:01:16 +02001911 select MMU_NOTIFIER
Jarkko Sakkinen901ddbb2021-03-18 01:53:31 +02001912 select NUMA_KEEP_MEMINFO if NUMA
Tony Luck40e0e782021-10-26 15:00:45 -07001913 select XARRAY_MULTI
Sean Christophersone7e05452020-11-13 00:01:16 +02001914 help
1915 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1916 that can be used by applications to set aside private regions of code
1917 and data, referred to as enclaves. An enclave's private memory can
1918 only be accessed by code running within the enclave. Accesses from
1919 outside the enclave, including other enclaves, are disallowed by
1920 hardware.
1921
1922 If unsure, say N.
1923
Rick Edgecombe18e66b62023-06-12 17:10:32 -07001924config X86_USER_SHADOW_STACK
1925 bool "X86 userspace shadow stack"
1926 depends on AS_WRUSS
1927 depends on X86_64
1928 select ARCH_USES_HIGH_VMA_FLAGS
1929 select X86_CET
1930 help
1931 Shadow stack protection is a hardware feature that detects function
1932 return address corruption. This helps mitigate ROP attacks.
1933 Applications must be enabled to use it, and old userspace does not
1934 get protection "for free".
1935
1936 CPUs supporting shadow stacks were first released in 2020.
1937
Dave Hansen54acee62023-08-02 13:37:22 -07001938 See Documentation/arch/x86/shstk.rst for more information.
Rick Edgecombe18e66b62023-06-12 17:10:32 -07001939
1940 If unsure, say N.
1941
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001942config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001943 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001944 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001945 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001946 select EFI_RUNTIME_WRAPPERS
Tom Lendacky1ff2fc02021-10-20 13:02:11 -05001947 select ARCH_USE_MEMREMAP_PROT
Ard Biesheuvelaba7e062023-08-02 17:17:04 +02001948 select EFI_RUNTIME_MAP if KEXEC_CORE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001949 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001950 This enables the kernel to use EFI runtime services that are
1951 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001952
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001953 This option is only useful on systems that have EFI firmware.
1954 In addition, you should use the latest ELILO loader available
1955 at <http://elilo.sourceforge.net> in order to take advantage
1956 of EFI runtime services. However, even with this option, the
1957 resultant kernel should continue to boot on existing non-EFI
1958 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001959
Matt Fleming291f3632011-12-12 21:27:52 +00001960config EFI_STUB
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001961 bool "EFI stub support"
Peter Zijlstrac6dbd3e2021-11-15 17:46:39 +01001962 depends on EFI
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001963 select RELOCATABLE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001964 help
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001965 This kernel feature allows a bzImage to be loaded directly
Matt Fleming291f3632011-12-12 21:27:52 +00001966 by EFI firmware without the use of a bootloader.
1967
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -03001968 See Documentation/admin-guide/efi-stub.rst for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001969
Ard Biesheuvelcc3fdda2022-11-22 17:10:17 +01001970config EFI_HANDOVER_PROTOCOL
1971 bool "EFI handover protocol (DEPRECATED)"
1972 depends on EFI_STUB
1973 default y
1974 help
1975 Select this in order to include support for the deprecated EFI
1976 handover protocol, which defines alternative entry points into the
1977 EFI stub. This is a practice that has no basis in the UEFI
1978 specification, and requires a priori knowledge on the part of the
1979 bootloader about Linux/x86 specific ways of passing the command line
1980 and initrd, and where in memory those assets may be loaded.
1981
1982 If in doubt, say Y. Even though the corresponding support is not
1983 present in upstream GRUB or other bootloaders, most distros build
1984 GRUB with numerous downstream patches applied, and may rely on the
1985 handover protocol as as result.
1986
Matt Fleming7d453ee2014-01-10 18:52:06 +00001987config EFI_MIXED
1988 bool "EFI mixed-mode support"
1989 depends on EFI_STUB && X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001990 help
Juerg Haefliger758cd942022-05-25 15:32:02 +02001991 Enabling this feature allows a 64-bit kernel to be booted
1992 on a 32-bit firmware, provided that your CPU supports 64-bit
1993 mode.
Matt Fleming7d453ee2014-01-10 18:52:06 +00001994
Juerg Haefliger758cd942022-05-25 15:32:02 +02001995 Note that it is not possible to boot a mixed-mode enabled
1996 kernel via the EFI boot stub - a bootloader that supports
1997 the EFI handover protocol must be used.
Matt Fleming7d453ee2014-01-10 18:52:06 +00001998
Juerg Haefliger758cd942022-05-25 15:32:02 +02001999 If unsure, say N.
Matt Fleming7d453ee2014-01-10 18:52:06 +00002000
Ard Biesheuvel4059ba62022-10-01 18:38:15 +02002001config EFI_FAKE_MEMMAP
2002 bool "Enable EFI fake memory map"
2003 depends on EFI
2004 help
2005 Saying Y here will enable "efi_fake_mem" boot option. By specifying
2006 this parameter, you can add arbitrary attribute to specific memory
2007 range by updating original (firmware provided) EFI memmap. This is
2008 useful for debugging of EFI memmap related feature, e.g., Address
2009 Range Mirroring feature.
2010
2011config EFI_MAX_FAKE_MEM
2012 int "maximum allowable number of ranges in efi_fake_mem boot option"
2013 depends on EFI_FAKE_MEMMAP
2014 range 1 128
2015 default 8
2016 help
2017 Maximum allowable number of ranges in efi_fake_mem boot option.
2018 Ranges can be set up to this value using comma-separated list.
2019 The default value is 8.
2020
Ard Biesheuvel1fff2342022-11-07 09:17:16 +01002021config EFI_RUNTIME_MAP
2022 bool "Export EFI runtime maps to sysfs" if EXPERT
2023 depends on EFI
Ard Biesheuvel1fff2342022-11-07 09:17:16 +01002024 help
2025 Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2026 That memory map is required by the 2nd kernel to set up EFI virtual
2027 mappings after kexec, but can also be used for debugging purposes.
2028
2029 See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2030
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09002031source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002032
Eric DeVolder6af51382023-07-12 12:15:33 -04002033config ARCH_SUPPORTS_KEXEC
2034 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002035
Eric DeVolder6af51382023-07-12 12:15:33 -04002036config ARCH_SUPPORTS_KEXEC_FILE
2037 def_bool X86_64 && CRYPTO && CRYPTO_SHA256
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002038
Eric DeVolder6af51382023-07-12 12:15:33 -04002039config ARCH_SELECTS_KEXEC_FILE
2040 def_bool y
2041 depends on KEXEC_FILE
Jonathan McDowellb69a2af2022-06-30 08:36:12 +00002042 select HAVE_IMA_KEXEC if IMA
Vivek Goyal74ca3172014-08-29 15:18:46 -07002043
Eric DeVoldere6265fe2023-07-12 12:15:45 -04002044config ARCH_SUPPORTS_KEXEC_PURGATORY
AKASHI Takahirob799a092018-04-13 15:35:45 -07002045 def_bool KEXEC_FILE
2046
Eric DeVolder6af51382023-07-12 12:15:33 -04002047config ARCH_SUPPORTS_KEXEC_SIG
2048 def_bool y
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002049
Eric DeVolder6af51382023-07-12 12:15:33 -04002050config ARCH_SUPPORTS_KEXEC_SIG_FORCE
2051 def_bool y
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002052
Eric DeVolder6af51382023-07-12 12:15:33 -04002053config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
2054 def_bool y
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002055
Eric DeVolder6af51382023-07-12 12:15:33 -04002056config ARCH_SUPPORTS_KEXEC_JUMP
2057 def_bool y
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002058
Eric DeVolder6af51382023-07-12 12:15:33 -04002059config ARCH_SUPPORTS_CRASH_DUMP
2060 def_bool X86_64 || (X86_32 && HIGHMEM)
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002061
Eric DeVolderea53ad92023-08-14 17:44:43 -04002062config ARCH_SUPPORTS_CRASH_HOTPLUG
2063 def_bool y
Huang Ying3ab83522008-07-25 19:45:07 -07002064
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002065config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002066 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002067 default "0x1000000"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002068 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002069 This gives the physical address where the kernel is loaded.
2070
2071 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2072 bzImage will decompress itself to above physical address and
2073 run from there. Otherwise, bzImage will run from the address where
2074 it has been loaded by the boot loader and will ignore above physical
2075 address.
2076
2077 In normal kdump cases one does not have to set/change this option
2078 as now bzImage can be compiled as a completely relocatable image
2079 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2080 address. This option is mainly useful for the folks who don't want
2081 to use a bzImage for capturing the crash dump and want to use a
2082 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2083 to be specifically compiled to run from a specific memory area
2084 (normally a reserved region) and this option comes handy.
2085
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002086 So if you are using bzImage for capturing the crash dump,
2087 leave the value here unchanged to 0x1000000 and set
2088 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2089 for capturing the crash dump change this value to start of
2090 the reserved region. In other words, it can be set based on
2091 the "X" value as specified in the "crashkernel=YM@XM"
2092 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002093 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002094 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002095
2096 Usage of bzImage for capturing the crash dump is recommended as
2097 one does not have to build two kernels. Same kernel can be used
2098 as production kernel and capture kernel. Above option should have
2099 gone away after relocatable bzImage support is introduced. But it
2100 is present because there are users out there who continue to use
2101 vmlinux for dump capture. This option should go away down the
2102 line.
2103
2104 Don't change this unless you know what you are doing.
2105
2106config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002107 bool "Build a relocatable kernel"
2108 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002109 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002110 This builds a kernel image that retains relocation information
2111 so it can be loaded someplace besides the default 1MB.
2112 The relocations tend to make the kernel binary about 10% larger,
2113 but are discarded at runtime.
2114
2115 One use is for the kexec on panic case where the recovery kernel
2116 must live at a different physical address than the primary
2117 kernel.
2118
2119 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2120 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002121 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002122
Kees Cook8ab38202013-10-10 17:18:14 -07002123config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002124 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002125 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002126 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002127 help
Baoquan Hee8581e32016-04-20 13:55:43 -07002128 In support of Kernel Address Space Layout Randomization (KASLR),
2129 this randomizes the physical address at which the kernel image
2130 is decompressed and the virtual address where the kernel
2131 image is mapped, as a security feature that deters exploit
2132 attempts relying on knowledge of the location of kernel
2133 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002134
Kees Cooked9f0072016-05-25 15:45:33 -07002135 On 64-bit, the kernel physical and virtual addresses are
2136 randomized separately. The physical address will be anywhere
2137 between 16MB and the top of physical memory (up to 64TB). The
2138 virtual address will be randomized from 16MB up to 1GB (9 bits
2139 of entropy). Note that this also reduces the memory space
2140 available to kernel modules from 1.5GB to 1GB.
2141
2142 On 32-bit, the kernel physical and virtual addresses are
2143 randomized together. They will be randomized from 16MB up to
2144 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002145
Baoquan Hee8581e32016-04-20 13:55:43 -07002146 Entropy is generated using the RDRAND instruction if it is
2147 supported. If RDTSC is supported, its value is mixed into
2148 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002149 supported, then entropy is read from the i8254 timer. The
2150 usable entropy is limited by the kernel being built using
2151 2GB addressing, and that PHYSICAL_ALIGN must be at a
2152 minimum of 2MB. As a result, only 10 bits of entropy are
2153 theoretically possible, but the implementations are further
2154 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002155
Ingo Molnar6807c842017-04-18 11:08:12 +02002156 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002157
2158# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002159config X86_NEED_RELOCS
2160 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002161 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002162
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002163config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002164 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002165 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002166 range 0x2000 0x1000000 if X86_32
2167 range 0x200000 0x1000000 if X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002168 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002169 This value puts the alignment restrictions on physical address
2170 where kernel is loaded and run from. Kernel is compiled for an
2171 address which meets above alignment restriction.
2172
2173 If bootloader loads the kernel at a non-aligned address and
2174 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2175 address aligned to above value and run from there.
2176
2177 If bootloader loads the kernel at a non-aligned address and
2178 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2179 load address and decompress itself to the address it has been
2180 compiled for and run from there. The address for which kernel is
2181 compiled already meets above alignment restrictions. Hence the
2182 end result is that kernel runs from a physical address meeting
2183 above alignment restrictions.
2184
Kees Cooka0215062013-07-08 09:15:17 -07002185 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2186 this value must be a multiple of 0x200000.
2187
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002188 Don't change this unless you know what you are doing.
2189
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002190config DYNAMIC_MEMORY_LAYOUT
2191 bool
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002192 help
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002193 This option makes base addresses of vmalloc and vmemmap as well as
2194 __PAGE_OFFSET movable during boot.
2195
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002196config RANDOMIZE_MEMORY
2197 bool "Randomize the kernel memory sections"
2198 depends on X86_64
2199 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002200 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002201 default RANDOMIZE_BASE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002202 help
Juerg Haefliger758cd942022-05-25 15:32:02 +02002203 Randomizes the base virtual address of kernel memory sections
2204 (physical memory mapping, vmalloc & vmemmap). This security feature
2205 makes exploits relying on predictable memory locations less reliable.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002206
Juerg Haefliger758cd942022-05-25 15:32:02 +02002207 The order of allocations remains unchanged. Entropy is generated in
2208 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2209 configuration have in average 30,000 different possible virtual
2210 addresses for each memory section.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002211
Juerg Haefliger758cd942022-05-25 15:32:02 +02002212 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002213
Thomas Garnier90397a42016-06-21 17:47:06 -07002214config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2215 hex "Physical memory mapping padding" if EXPERT
2216 depends on RANDOMIZE_MEMORY
2217 default "0xa" if MEMORY_HOTPLUG
2218 default "0x0"
2219 range 0x1 0x40 if MEMORY_HOTPLUG
2220 range 0x0 0x40
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002221 help
Juerg Haefliger758cd942022-05-25 15:32:02 +02002222 Define the padding in terabytes added to the existing physical
2223 memory size during kernel memory randomization. It is useful
2224 for memory hotplug support but reduces the entropy available for
2225 address randomization.
Thomas Garnier90397a42016-06-21 17:47:06 -07002226
Juerg Haefliger758cd942022-05-25 15:32:02 +02002227 If unsure, leave at the default value.
Thomas Garnier90397a42016-06-21 17:47:06 -07002228
Kirill A. Shutemov6449dcb2023-03-12 14:25:58 +03002229config ADDRESS_MASKING
2230 bool "Linear Address Masking support"
2231 depends on X86_64
2232 help
2233 Linear Address Masking (LAM) modifies the checking that is applied
2234 to 64-bit linear addresses, allowing software to use of the
2235 untranslated address bits for metadata.
2236
2237 The capability can be used for efficient address sanitizers (ASAN)
2238 implementation and for optimizations in JITs.
2239
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002240config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002241 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002242 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002243
2244config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002245 def_bool n
2246 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002247 depends on COMPAT_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002248 help
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002249 Certain buggy versions of glibc will crash if they are
2250 presented with a 32-bit vDSO that is not mapped at the address
2251 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002252
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002253 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2254 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2255 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2256 the only released version with the bug, but OpenSUSE 9
2257 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002258
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002259 The symptom of the bug is that everything crashes on startup, saying:
2260 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2261
2262 Saying Y here changes the default value of the vdso32 boot
2263 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2264 This works around the glibc bug but hurts performance.
2265
2266 If unsure, say N: if you are compiling your own kernel, you
2267 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002268
Kees Cook3dc33bd2015-08-12 17:55:19 -07002269choice
2270 prompt "vsyscall table for legacy applications"
2271 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002272 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002273 help
2274 Legacy user code that does not know how to find the vDSO expects
2275 to be able to issue three syscalls by calling fixed addresses in
2276 kernel space. Since this location is not randomized with ASLR,
2277 it can be used to assist security vulnerability exploitation.
2278
2279 This setting can be changed at boot time via the kernel command
Andy Lutomirskibf007452022-05-11 10:38:53 -07002280 line parameter vsyscall=[emulate|xonly|none]. Emulate mode
2281 is deprecated and can only be enabled using the kernel command
2282 line.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002283
2284 On a system with recent enough glibc (2.14 or newer) and no
2285 static binaries, you can say None without a performance penalty
2286 to improve security.
2287
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002288 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002289
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002290 config LEGACY_VSYSCALL_XONLY
2291 bool "Emulate execution only"
2292 help
2293 The kernel traps and emulates calls into the fixed vsyscall
2294 address mapping and does not allow reads. This
2295 configuration is recommended when userspace might use the
2296 legacy vsyscall area but support for legacy binary
2297 instrumentation of legacy code is not needed. It mitigates
2298 certain uses of the vsyscall area as an ASLR-bypassing
2299 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002300
2301 config LEGACY_VSYSCALL_NONE
2302 bool "None"
2303 help
2304 There will be no vsyscall mapping at all. This will
2305 eliminate any risk of ASLR bypass due to the vsyscall
2306 fixed address mapping. Attempts to use the vsyscalls
2307 will be reported to dmesg, so that either old or
2308 malicious userspace programs can be identified.
2309
2310endchoice
2311
Tim Bird516cbf32008-08-12 12:52:36 -07002312config CMDLINE_BOOL
2313 bool "Built-in kernel command line"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002314 help
Tim Bird516cbf32008-08-12 12:52:36 -07002315 Allow for specifying boot arguments to the kernel at
2316 build time. On some systems (e.g. embedded ones), it is
2317 necessary or convenient to provide some or all of the
2318 kernel boot arguments with the kernel itself (that is,
2319 to not rely on the boot loader to provide them.)
2320
2321 To compile command line arguments into the kernel,
2322 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002323 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002324
2325 Systems with fully functional boot loaders (i.e. non-embedded)
2326 should leave this option set to 'N'.
2327
2328config CMDLINE
2329 string "Built-in kernel command string"
2330 depends on CMDLINE_BOOL
2331 default ""
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002332 help
Tim Bird516cbf32008-08-12 12:52:36 -07002333 Enter arguments here that should be compiled into the kernel
2334 image and used at boot time. If the boot loader provides a
2335 command line at boot time, it is appended to this string to
2336 form the full kernel command line, when the system boots.
2337
2338 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2339 change this behavior.
2340
2341 In most cases, the command line (whether built-in or provided
2342 by the boot loader) should specify the device for the root
2343 file system.
2344
2345config CMDLINE_OVERRIDE
2346 bool "Built-in command line overrides boot loader arguments"
Anders Roxell645e6462020-01-24 12:46:15 +01002347 depends on CMDLINE_BOOL && CMDLINE != ""
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002348 help
Tim Bird516cbf32008-08-12 12:52:36 -07002349 Set this option to 'Y' to have the kernel ignore the boot loader
2350 command line, and use ONLY the built-in command line.
2351
2352 This is used to work around broken boot loaders. This should
2353 be set to 'N' under normal conditions.
2354
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002355config MODIFY_LDT_SYSCALL
2356 bool "Enable the LDT (local descriptor table)" if EXPERT
2357 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002358 help
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002359 Linux can allow user programs to install a per-process x86
2360 Local Descriptor Table (LDT) using the modify_ldt(2) system
2361 call. This is required to run 16-bit or segmented code such as
2362 DOSEMU or some Wine programs. It is also used by some very old
2363 threading libraries.
2364
2365 Enabling this feature adds a small amount of overhead to
2366 context switches and increases the low-level kernel attack
2367 surface. Disabling it removes the modify_ldt(2) system call.
2368
2369 Saying 'N' here may make sense for embedded or server kernels.
2370
Thomas Gleixner3aac3eb2021-10-21 15:55:06 -07002371config STRICT_SIGALTSTACK_SIZE
2372 bool "Enforce strict size checking for sigaltstack"
2373 depends on DYNAMIC_SIGFRAME
2374 help
2375 For historical reasons MINSIGSTKSZ is a constant which became
2376 already too small with AVX512 support. Add a mechanism to
2377 enforce strict checking of the sigaltstack size against the
2378 real size of the FPU frame. This option enables the check
2379 by default. It can also be controlled via the kernel command
2380 line option 'strict_sas_size' independent of this config
2381 switch. Enabling it might break existing applications which
2382 allocate a too small sigaltstack but 'work' because they
2383 never get a signal delivered.
2384
2385 Say 'N' unless you want to really enforce this check.
2386
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002387source "kernel/livepatch/Kconfig"
2388
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002389endmenu
2390
Peter Zijlstraf43b98762022-06-27 22:21:17 +00002391config CC_HAS_SLS
2392 def_bool $(cc-option,-mharden-sls=all)
2393
2394config CC_HAS_RETURN_THUNK
2395 def_bool $(cc-option,-mfunction-return=thunk-extern)
2396
Thomas Gleixnerbea75b32022-09-15 13:11:18 +02002397config CC_HAS_ENTRY_PADDING
2398 def_bool $(cc-option,-fpatchable-function-entry=16,16)
2399
2400config FUNCTION_PADDING_CFI
2401 int
2402 default 59 if FUNCTION_ALIGNMENT_64B
2403 default 27 if FUNCTION_ALIGNMENT_32B
2404 default 11 if FUNCTION_ALIGNMENT_16B
2405 default 3 if FUNCTION_ALIGNMENT_8B
2406 default 0
2407
2408# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2409# except Kconfig can't do arithmetic :/
2410config FUNCTION_PADDING_BYTES
2411 int
2412 default FUNCTION_PADDING_CFI if CFI_CLANG
2413 default FUNCTION_ALIGNMENT
2414
Peter Zijlstra931ab632022-10-27 11:28:14 +02002415config CALL_PADDING
2416 def_bool n
2417 depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2418 select FUNCTION_ALIGNMENT_16B
2419
2420config FINEIBT
2421 def_bool y
2422 depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2423 select CALL_PADDING
2424
Thomas Gleixner8f7c0d82022-09-15 13:11:17 +02002425config HAVE_CALL_THUNKS
2426 def_bool y
Thomas Gleixnerbea75b32022-09-15 13:11:18 +02002427 depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
Thomas Gleixner8f7c0d82022-09-15 13:11:17 +02002428
2429config CALL_THUNKS
2430 def_bool n
Peter Zijlstra931ab632022-10-27 11:28:14 +02002431 select CALL_PADDING
Thomas Gleixner8f7c0d82022-09-15 13:11:17 +02002432
Peter Zijlstrab341b202022-10-28 21:08:19 +02002433config PREFIX_SYMBOLS
2434 def_bool y
Peter Zijlstra931ab632022-10-27 11:28:14 +02002435 depends on CALL_PADDING && !CFI_CLANG
Peter Zijlstrab341b202022-10-28 21:08:19 +02002436
Peter Zijlstraf43b98762022-06-27 22:21:17 +00002437menuconfig SPECULATION_MITIGATIONS
2438 bool "Mitigations for speculative execution vulnerabilities"
2439 default y
2440 help
2441 Say Y here to enable options which enable mitigations for
2442 speculative execution hardware vulnerabilities.
2443
2444 If you say N, all mitigations will be disabled. You really
2445 should know what you are doing to say so.
2446
2447if SPECULATION_MITIGATIONS
2448
2449config PAGE_TABLE_ISOLATION
2450 bool "Remove the kernel mapping in user mode"
2451 default y
2452 depends on (X86_64 || X86_PAE)
2453 help
2454 This feature reduces the number of hardware side channels by
2455 ensuring that the majority of kernel addresses are not mapped
2456 into userspace.
2457
Jonathan Corbetff61f072023-03-14 17:06:44 -06002458 See Documentation/arch/x86/pti.rst for more details.
Peter Zijlstraf43b98762022-06-27 22:21:17 +00002459
2460config RETPOLINE
2461 bool "Avoid speculative indirect branches in kernel"
2462 select OBJTOOL if HAVE_OBJTOOL
2463 default y
2464 help
2465 Compile kernel with the retpoline compiler options to guard against
2466 kernel-to-user data leaks by avoiding speculative indirect
2467 branches. Requires a compiler with -mindirect-branch=thunk-extern
2468 support for full protection. The kernel may run slower.
2469
2470config RETHUNK
2471 bool "Enable return-thunks"
2472 depends on RETPOLINE && CC_HAS_RETURN_THUNK
2473 select OBJTOOL if HAVE_OBJTOOL
Ben Hutchingsb648ab42022-07-23 17:22:47 +02002474 default y if X86_64
Peter Zijlstraf43b98762022-06-27 22:21:17 +00002475 help
2476 Compile the kernel with the return-thunks compiler option to guard
2477 against kernel-to-user data leaks by avoiding return speculation.
2478 Requires a compiler with -mfunction-return=thunk-extern
2479 support for full protection. The kernel may run slower.
2480
2481config CPU_UNRET_ENTRY
2482 bool "Enable UNRET on kernel entry"
Ben Hutchingsb648ab42022-07-23 17:22:47 +02002483 depends on CPU_SUP_AMD && RETHUNK && X86_64
Peter Zijlstraf43b98762022-06-27 22:21:17 +00002484 default y
2485 help
2486 Compile the kernel with support for the retbleed=unret mitigation.
2487
Thomas Gleixner80e4c1c2022-09-15 13:11:19 +02002488config CALL_DEPTH_TRACKING
2489 bool "Mitigate RSB underflow with call depth tracking"
2490 depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2491 select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2492 select CALL_THUNKS
2493 default y
2494 help
2495 Compile the kernel with call depth tracking to mitigate the Intel
2496 SKL Return-Speculation-Buffer (RSB) underflow issue. The
2497 mitigation is off by default and needs to be enabled on the
2498 kernel command line via the retbleed=stuff option. For
2499 non-affected systems the overhead of this option is marginal as
2500 the call depth tracking is using run-time generated call thunks
2501 in a compiler generated padding area and call patching. This
2502 increases text size by ~5%. For non affected systems this space
2503 is unused. On affected SKL systems this results in a significant
2504 performance gain over the IBRS mitigation.
2505
Thomas Gleixnere81dc122022-09-15 13:11:23 +02002506config CALL_THUNKS_DEBUG
2507 bool "Enable call thunks and call depth tracking debugging"
2508 depends on CALL_DEPTH_TRACKING
2509 select FUNCTION_ALIGNMENT_32B
2510 default n
2511 help
2512 Enable call/ret counters for imbalance detection and build in
2513 a noisy dmesg about callthunks generation and call patching for
2514 trouble shooting. The debug prints need to be enabled on the
2515 kernel command line with 'debug-callthunks'.
Randy Dunlap54628de2023-01-24 10:17:53 -08002516 Only enable this when you are debugging call thunks as this
2517 creates a noticeable runtime overhead. If unsure say N.
Thomas Gleixner80e4c1c2022-09-15 13:11:19 +02002518
Peter Zijlstraf43b98762022-06-27 22:21:17 +00002519config CPU_IBPB_ENTRY
2520 bool "Enable IBPB on kernel entry"
Ben Hutchingsb648ab42022-07-23 17:22:47 +02002521 depends on CPU_SUP_AMD && X86_64
Peter Zijlstraf43b98762022-06-27 22:21:17 +00002522 default y
2523 help
2524 Compile the kernel with support for the retbleed=ibpb mitigation.
2525
2526config CPU_IBRS_ENTRY
2527 bool "Enable IBRS on kernel entry"
Ben Hutchingsb648ab42022-07-23 17:22:47 +02002528 depends on CPU_SUP_INTEL && X86_64
Peter Zijlstraf43b98762022-06-27 22:21:17 +00002529 default y
2530 help
2531 Compile the kernel with support for the spectre_v2=ibrs mitigation.
2532 This mitigates both spectre_v2 and retbleed at great cost to
2533 performance.
2534
Borislav Petkov (AMD)fb3bd912023-06-28 11:02:39 +02002535config CPU_SRSO
2536 bool "Mitigate speculative RAS overflow on AMD"
2537 depends on CPU_SUP_AMD && X86_64 && RETHUNK
2538 default y
2539 help
2540 Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2541
Peter Zijlstraf43b98762022-06-27 22:21:17 +00002542config SLS
2543 bool "Mitigate Straight-Line-Speculation"
2544 depends on CC_HAS_SLS && X86_64
2545 select OBJTOOL if HAVE_OBJTOOL
2546 default n
2547 help
2548 Compile the kernel with straight-line-speculation options to guard
2549 against straight line speculation. The kernel image might be slightly
2550 larger.
2551
Daniel Sneddon53cf5792023-07-12 19:43:13 -07002552config GDS_FORCE_MITIGATION
2553 bool "Force GDS Mitigation"
2554 depends on CPU_SUP_INTEL
2555 default n
2556 help
2557 Gather Data Sampling (GDS) is a hardware vulnerability which allows
2558 unprivileged speculative access to data which was previously stored in
2559 vector registers.
2560
2561 This option is equivalent to setting gather_data_sampling=force on the
2562 command line. The microcode mitigation is used if present, otherwise
2563 AVX is disabled as a mitigation. On affected systems that are missing
2564 the microcode any userspace code that unconditionally uses AVX will
2565 break with this option set.
2566
2567 Setting this option on systems not vulnerable to GDS has no effect.
2568
2569 If in doubt, say N.
2570
Peter Zijlstraf43b98762022-06-27 22:21:17 +00002571endif
2572
Michal Hocko3072e412017-09-08 16:11:39 -07002573config ARCH_HAS_ADD_PAGES
2574 def_bool y
David Hildenbrand5c11f00b2021-11-05 13:44:39 -07002575 depends on ARCH_ENABLE_MEMORY_HOTPLUG
Michal Hocko3072e412017-09-08 16:11:39 -07002576
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002577menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002578
2579config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002580 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002581 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002582
2583source "kernel/power/Kconfig"
2584
2585source "drivers/acpi/Kconfig"
2586
Andi Kleena6b68072008-01-30 13:32:49 +01002587config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002588 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002589 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002590
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002591menuconfig APM
2592 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002593 depends on X86_32 && PM_SLEEP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002594 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002595 APM is a BIOS specification for saving power using several different
2596 techniques. This is mostly useful for battery powered laptops with
2597 APM compliant BIOSes. If you say Y here, the system time will be
2598 reset after a RESUME operation, the /proc/apm device will provide
2599 battery status information, and user-space programs will receive
2600 notification of APM "events" (e.g. battery status change).
2601
2602 If you select "Y" here, you can disable actual use of the APM
2603 BIOS by passing the "apm=off" option to the kernel at boot time.
2604
2605 Note that the APM support is almost completely disabled for
2606 machines with more than one CPU.
2607
2608 In order to use APM, you will need supporting software. For location
Mauro Carvalho Chehab151f4e22019-06-13 07:10:36 -03002609 and more information, read <file:Documentation/power/apm-acpi.rst>
Michael Witten2dc98fd2011-07-08 21:11:16 +00002610 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002611 <http://www.tldp.org/docs.html#howto>.
2612
2613 This driver does not spin down disk drives (see the hdparm(8)
2614 manpage ("man 8 hdparm") for that), and it doesn't turn off
2615 VESA-compliant "green" monitors.
2616
2617 This driver does not support the TI 4000M TravelMate and the ACER
2618 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2619 desktop machines also don't have compliant BIOSes, and this driver
2620 may cause those machines to panic during the boot phase.
2621
2622 Generally, if you don't have a battery in your machine, there isn't
2623 much point in using this driver and you should say N. If you get
2624 random kernel OOPSes or reboots that don't seem to be related to
2625 anything, try disabling/enabling this option (or disabling/enabling
2626 APM in your BIOS).
2627
2628 Some other things you should try when experiencing seemingly random,
2629 "weird" problems:
2630
2631 1) make sure that you have enough swap space and that it is
2632 enabled.
Stephen Kitt79874482022-07-13 18:08:40 +02002633 2) pass the "idle=poll" option to the kernel
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002634 3) switch on floating point emulation in the kernel and pass
2635 the "no387" option to the kernel
2636 4) pass the "floppy=nodma" option to the kernel
2637 5) pass the "mem=4M" option to the kernel (thereby disabling
2638 all but the first 4 MB of RAM)
2639 6) make sure that the CPU is not over clocked.
2640 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2641 8) disable the cache from your BIOS settings
2642 9) install a fan for the video card or exchange video RAM
2643 10) install a better fan for the CPU
2644 11) exchange RAM chips
2645 12) exchange the motherboard.
2646
2647 To compile this driver as a module, choose M here: the
2648 module will be called apm.
2649
2650if APM
2651
2652config APM_IGNORE_USER_SUSPEND
2653 bool "Ignore USER SUSPEND"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002654 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002655 This option will ignore USER SUSPEND requests. On machines with a
2656 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2657 series notebooks, it is necessary to say Y because of a BIOS bug.
2658
2659config APM_DO_ENABLE
2660 bool "Enable PM at boot time"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002661 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002662 Enable APM features at boot time. From page 36 of the APM BIOS
2663 specification: "When disabled, the APM BIOS does not automatically
2664 power manage devices, enter the Standby State, enter the Suspend
2665 State, or take power saving steps in response to CPU Idle calls."
2666 This driver will make CPU Idle calls when Linux is idle (unless this
2667 feature is turned off -- see "Do CPU IDLE calls", below). This
2668 should always save battery power, but more complicated APM features
2669 will be dependent on your BIOS implementation. You may need to turn
2670 this option off if your computer hangs at boot time when using APM
2671 support, or if it beeps continuously instead of suspending. Turn
2672 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2673 T400CDT. This is off by default since most machines do fine without
2674 this feature.
2675
2676config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002677 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002678 bool "Make CPU Idle calls when idle"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002679 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002680 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2681 On some machines, this can activate improved power savings, such as
2682 a slowed CPU clock rate, when the machine is idle. These idle calls
2683 are made after the idle loop has run for some length of time (e.g.,
2684 333 mS). On some machines, this will cause a hang at boot time or
2685 whenever the CPU becomes idle. (On machines with more than one CPU,
2686 this option does nothing.)
2687
2688config APM_DISPLAY_BLANK
2689 bool "Enable console blanking using APM"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002690 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002691 Enable console blanking using the APM. Some laptops can use this to
2692 turn off the LCD backlight when the screen blanker of the Linux
2693 virtual console blanks the screen. Note that this is only used by
2694 the virtual console screen blanker, and won't turn off the backlight
2695 when using the X Window system. This also doesn't have anything to
2696 do with your VESA-compliant power-saving monitor. Further, this
2697 option doesn't work for all laptops -- it might not turn off your
2698 backlight at all, or it might print a lot of errors to the console,
2699 especially if you are using gpm.
2700
2701config APM_ALLOW_INTS
2702 bool "Allow interrupts during APM BIOS calls"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002703 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002704 Normally we disable external interrupts while we are making calls to
2705 the APM BIOS as a measure to lessen the effects of a badly behaving
2706 BIOS implementation. The BIOS should reenable interrupts if it
2707 needs to. Unfortunately, some BIOSes do not -- especially those in
2708 many of the newer IBM Thinkpads. If you experience hangs when you
2709 suspend, try setting this to Y. Otherwise, say N.
2710
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002711endif # APM
2712
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002713source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002714
2715source "drivers/cpuidle/Kconfig"
2716
Andy Henroid27471fd2008-10-09 11:45:22 -07002717source "drivers/idle/Kconfig"
2718
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002719endmenu
2720
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002721menu "Bus options (PCI etc.)"
2722
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002723choice
2724 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002725 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002726 default PCI_GOANY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002727 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002728 On PCI systems, the BIOS can be used to detect the PCI devices and
2729 determine their configuration. However, some old PCI motherboards
2730 have BIOS bugs and may crash if this is done. Also, some embedded
2731 PCI-based systems don't have any BIOS at all. Linux can also try to
2732 detect the PCI hardware directly without using the BIOS.
2733
2734 With this option, you can specify how Linux should detect the
2735 PCI devices. If you choose "BIOS", the BIOS will be used,
2736 if you choose "Direct", the BIOS won't be used, and if you
2737 choose "MMConfig", then PCI Express MMCONFIG will be used.
2738 If you choose "Any", the kernel will try MMCONFIG, then the
2739 direct access method and falls back to the BIOS if that doesn't
2740 work. If unsure, go with the default, which is "Any".
2741
2742config PCI_GOBIOS
2743 bool "BIOS"
2744
2745config PCI_GOMMCONFIG
2746 bool "MMConfig"
2747
2748config PCI_GODIRECT
2749 bool "Direct"
2750
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002751config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002752 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002753 depends on OLPC
2754
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002755config PCI_GOANY
2756 bool "Any"
2757
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002758endchoice
2759
2760config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002761 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002762 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002763
2764# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2765config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002766 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002767 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002768
2769config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002770 bool "Support mmconfig PCI config space access" if X86_64
2771 default y
Andy Shevchenko4590d982021-02-11 15:40:02 +02002772 depends on PCI && (ACPI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002773 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002774
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002775config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002776 def_bool y
2777 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002778
Alex Nixonb5401a92010-03-18 16:31:34 -04002779config PCI_XEN
2780 def_bool y
2781 depends on PCI && XEN
Alex Nixonb5401a92010-03-18 16:31:34 -04002782
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002783config MMCONF_FAM10H
2784 def_bool y
2785 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002786
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002787config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002788 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002789 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002790 help
2791 Read the PCI windows out of the CNB20LE host bridge. This allows
2792 PCI hotplug to work on systems with the CNB20LE chipset which do
2793 not have ACPI.
2794
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002795 There's no public spec for this chipset, and this functionality
2796 is known to be incomplete.
2797
2798 You should say N unless you know you need this.
2799
William Breathitt Gray3a495512016-05-27 18:08:27 -04002800config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002801 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002802 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002803 Expose ISA bus device drivers and options available for selection and
2804 configuration. Enable this option if your target machine has an ISA
2805 bus. ISA is an older system, displaced by PCI and newer bus
2806 architectures -- if your target machine is modern, it probably does
2807 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002808
2809 If unsure, say N.
2810
David Rientjes1c00f012011-03-22 16:34:59 -07002811# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002812config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002813 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2814 default y
2815 help
2816 Enables ISA-style DMA support for devices requiring such controllers.
2817 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002818
Linus Torvalds51e68d02016-05-21 10:25:19 -07002819if X86_32
2820
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002821config ISA
2822 bool "ISA support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002823 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002824 Find out whether you have ISA slots on your motherboard. ISA is the
2825 name of a bus system, i.e. the way the CPU talks to the other stuff
2826 inside your box. Other bus systems are PCI, EISA, MicroChannel
2827 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2828 newer boards don't support it. If you have ISA, say Y, otherwise N.
2829
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002830config SCx200
2831 tristate "NatSemi SCx200 support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002832 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002833 This provides basic support for National Semiconductor's
2834 (now AMD's) Geode processors. The driver probes for the
2835 PCI-IDs of several on-chip devices, so its a good dependency
2836 for other scx200_* drivers.
2837
2838 If compiled as a module, the driver is named scx200.
2839
2840config SCx200HR_TIMER
2841 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002842 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002843 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002844 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002845 This driver provides a clocksource built upon the on-chip
2846 27MHz high-resolution timer. Its also a workaround for
2847 NSC Geode SC-1100's buggy TSC, which loses time when the
2848 processor goes idle (as is done by the scheduler). The
2849 other workaround is idle=poll boot option.
2850
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002851config OLPC
2852 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002853 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002854 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002855 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002856 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002857 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002858 select OLPC_EC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002859 help
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002860 Add support for detecting the unique features of the OLPC
2861 XO hardware.
2862
Daniel Drakea3128582011-06-25 17:34:10 +01002863config OLPC_XO1_PM
2864 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002865 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002866 help
Daniel Drake97c4cb72011-06-25 17:34:11 +01002867 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002868
Daniel Drakecfee9592011-06-25 17:34:17 +01002869config OLPC_XO1_RTC
2870 bool "OLPC XO-1 Real Time Clock"
2871 depends on OLPC_XO1_PM && RTC_DRV_CMOS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002872 help
Daniel Drakecfee9592011-06-25 17:34:17 +01002873 Add support for the XO-1 real time clock, which can be used as a
2874 programmable wakeup source.
2875
Daniel Drake7feda8e92011-06-25 17:34:12 +01002876config OLPC_XO1_SCI
2877 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002878 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002879 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002880 select POWER_SUPPLY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002881 help
Daniel Drake7feda8e92011-06-25 17:34:12 +01002882 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002883 - EC-driven system wakeups
Daniel Drake7feda8e92011-06-25 17:34:12 +01002884 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002885 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002886 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002887 - AC adapter status updates
2888 - Battery status updates
Daniel Drake7feda8e92011-06-25 17:34:12 +01002889
Daniel Drakea0f30f52011-06-25 17:34:18 +01002890config OLPC_XO15_SCI
2891 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002892 depends on OLPC && ACPI
2893 select POWER_SUPPLY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002894 help
Daniel Drakea0f30f52011-06-25 17:34:18 +01002895 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2896 - EC-driven system wakeups
2897 - AC adapter status updates
2898 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002899
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002900config ALIX
2901 bool "PCEngines ALIX System Support (LED setup)"
2902 select GPIOLIB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002903 help
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002904 This option enables system support for the PCEngines ALIX.
2905 At present this just sets up LEDs for GPIO control on
2906 ALIX2/3/6 boards. However, other system specific setup should
2907 get added here.
2908
2909 Note: You must still enable the drivers for GPIO and LED support
2910 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2911
2912 Note: You have to set alix.force=1 for boards with Award BIOS.
2913
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002914config NET5501
2915 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2916 select GPIOLIB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002917 help
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002918 This option enables system support for the Soekris Engineering net5501.
2919
Philip A. Prindeville31970592012-01-14 01:45:39 -07002920config GEOS
2921 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2922 select GPIOLIB
2923 depends on DMI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002924 help
Philip A. Prindeville31970592012-01-14 01:45:39 -07002925 This option enables system support for the Traverse Technologies GEOS.
2926
Vivien Didelot7d029122013-01-04 16:18:14 -05002927config TS5500
2928 bool "Technologic Systems TS-5500 platform support"
2929 depends on MELAN
2930 select CHECK_SIGNATURE
2931 select NEW_LEDS
2932 select LEDS_CLASS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002933 help
Vivien Didelot7d029122013-01-04 16:18:14 -05002934 This option enables system support for the Technologic Systems TS-5500.
2935
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002936endif # X86_32
2937
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002938config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002939 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002940 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002941
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002942endmenu
2943
Christoph Hellwig15724972018-07-31 13:39:30 +02002944menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002945
2946config IA32_EMULATION
2947 bool "IA32 Emulation"
2948 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002949 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002950 select BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002951 select COMPAT_OLD_SIGACTION
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002952 help
H. J. Lu5fd92e62012-02-19 10:40:03 -08002953 Include code to run legacy 32-bit programs under a
2954 64-bit kernel. You should likely turn this on, unless you're
2955 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002956
Masahiro Yamada83a44a42022-03-14 12:48:41 -07002957config X86_X32_ABI
Kees Cook6ea30382012-10-02 11:16:47 -07002958 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002959 depends on X86_64
Nathan Chancelloraaeed6e2022-03-14 12:48:42 -07002960 # llvm-objcopy does not convert x86_64 .note.gnu.property or
2961 # compressed debug sections to x86_x32 properly:
2962 # https://github.com/ClangBuiltLinux/linux/issues/514
2963 # https://github.com/ClangBuiltLinux/linux/issues/1141
2964 depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002965 help
H. J. Lu5fd92e62012-02-19 10:40:03 -08002966 Include code to run binaries for the x32 native 32-bit ABI
2967 for 64-bit processors. An x32 process gets access to the
2968 full 64-bit register file and wide data path while leaving
2969 pointers at 32 bits for smaller memory footprint.
2970
Ingo Molnar953fee12016-11-15 10:22:52 +01002971config COMPAT_32
2972 def_bool y
2973 depends on IA32_EMULATION || X86_32
2974 select HAVE_UID16
2975 select OLD_SIGSUSPEND3
2976
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002977config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002978 def_bool y
Masahiro Yamada83a44a42022-03-14 12:48:41 -07002979 depends on IA32_EMULATION || X86_X32_ABI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002980
2981config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002982 def_bool y
Linus Torvaldsa92512802022-06-05 10:53:41 -07002983 depends on COMPAT
David Howellsee009e4a02011-03-07 15:06:20 +00002984
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002985endmenu
2986
Keith Packarde5beae12008-11-03 18:21:45 +01002987config HAVE_ATOMIC_IOMAP
2988 def_bool y
2989 depends on X86_32
2990
Avi Kivityedf88412007-12-16 11:02:48 +02002991source "arch/x86/kvm/Kconfig"
Jason A. Donenfeld5e8ebd82020-03-26 17:00:58 +09002992
2993source "arch/x86/Kconfig.assembler"