xref: /linux/arch/x86/Kconfig (revision 25176ad09ca395fcc83b1fc78adf25c8eb1bd964)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
6a7f7f624SMasahiro Yamada	help
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17157e118bSThomas Gleixner	select GENERIC_VDSO_32
18117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
19157e118bSThomas Gleixner	select KMAP_LOCAL
20341c787eSIngo Molnar	select MODULES_USE_ELF_REL
21341c787eSIngo Molnar	select OLD_SIGACTION
222ca408d9SBrian Gerst	select ARCH_SPLIT_ARG64
23daa93fabSSam Ravnborg
24daa93fabSSam Ravnborgconfig X86_64
253120e25eSJan Beulich	def_bool y
263120e25eSJan Beulich	depends on 64BIT
27d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
284eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
29c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
300bff0aaeSSuren Baghdasaryan	select ARCH_SUPPORTS_PER_VMA_LOCK
31d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
32d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
33f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3409230cbcSChristoph Hellwig	select SWIOTLB
357facdc42SAl Viro	select ARCH_HAS_ELFCORE_COMPAT
3663703f37SKefeng Wang	select ZONE_DMA32
371032c0baSSam Ravnborg
38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
39518049d9SSteven Rostedt (VMware)	def_bool y
40518049d9SSteven Rostedt (VMware)	depends on X86_32
41518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
42518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
43518049d9SSteven Rostedt (VMware)	help
44518049d9SSteven Rostedt (VMware)	  We keep the static function tracing (!DYNAMIC_FTRACE) around
45518049d9SSteven Rostedt (VMware)	  in order to test the non static function tracing in the
46518049d9SSteven Rostedt (VMware)	  generic code, as other architectures still use it. But we
47518049d9SSteven Rostedt (VMware)	  only need to keep it around for x86_64. No need to keep it
48518049d9SSteven Rostedt (VMware)	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
49d94e0685SIngo Molnar#
50d94e0685SIngo Molnar# Arch settings
51d94e0685SIngo Molnar#
52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
53d94e0685SIngo Molnar#   ported to 32-bit as well. )
54d94e0685SIngo Molnar#
558d5fffb9SSam Ravnborgconfig X86
563c2362e6SHarvey Harrison	def_bool y
57c763ea26SIngo Molnar	#
58c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
59c763ea26SIngo Molnar	#
606471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
616e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62a02f66bbSJames Morse	select ACPI_HOTPLUG_CPU			if ACPI_PROCESSOR && HOTPLUG_CPU
63942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
642a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
651f6d3a8fSMasami Hiramatsu	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
661e866974SAnshuman Khandual	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
675c11f00bSDavid Hildenbrand	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
6891024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
69cebc774fSAnshuman Khandual	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
701e866974SAnshuman Khandual	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
7191dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
72c2280be8SAnshuman Khandual	select ARCH_HAS_CACHE_LINE_SIZE
731156b441SDavidlohr Bueso	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
747c7077a7SThomas Gleixner	select ARCH_HAS_CPU_FINALIZE_INIT
758f23f5dbSJason Gunthorpe	select ARCH_HAS_CPU_PASID		if IOMMU_SVA
762792d84eSKees Cook	select ARCH_HAS_CURRENT_STACK_POINTER
77fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
78399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
7921266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
80b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
816471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
8272d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
836974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
84957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
85bece04b5SMarco Elver	select ARCH_HAS_KCOV			if X86_64
860c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
8710bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
8849f88c70SPaul E. McKenney	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
890ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
90c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
9117596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
923010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
9371ce1ab5SKinsey Ho	select ARCH_HAS_HW_PTE_YOUNG
94eed9a328SYu Zhao	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
950aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
96ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
97d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
98d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
99ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
100ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
101ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
10225c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
103918327e9SKees Cook	select ARCH_HAS_UBSAN
1047e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
10563703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
1066471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
10704d5ea46SAneesh Kumar K.V	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
1086471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
10977fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1105e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1113599fe12SThomas Gleixner	select ARCH_STACKWALK
1122c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1136471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1145d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
115d283d422SPasha Tatashin	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
1166471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
11714df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
1183c516f89SSami Tolvanen	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
1193c516f89SSami Tolvanen	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
120583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
121583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1226471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
123a432b7c0SUros Bizjak	select ARCH_USE_CMPXCHG_LOCKREF		if X86_CMPXCHG64
124dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1256471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1266471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1272ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
128ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
12981c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
130c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
13151c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
13207431506SAnshuman Khandual	select ARCH_WANT_GENERAL_HUGETLB
1333876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
13459612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
1350b6f1582SAneesh Kumar K.V	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
1360b6f1582SAneesh Kumar K.V	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
13738d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
138b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
13910916706SShile Zhang	select BUILDTIME_TABLE_SORT
1406471b825SIngo Molnar	select CLKEVT_I8253
1416471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1426471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1437cf8f44aSAlexander Potapenko	# Word-size accesses may read uninitialized data past the trailing \0
1447cf8f44aSAlexander Potapenko	# in strings and cause false KMSAN reports.
1457cf8f44aSAlexander Potapenko	select DCACHE_WORD_ACCESS		if !KMSAN
1463aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
14745471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
14845471cd9SLinus Torvalds	select EDAC_SUPPORT
1496471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
150cb81deefSThomas Gleixner	select GENERIC_CLOCKEVENTS_BROADCAST_IDLE	if GENERIC_CLOCKEVENTS_BROADCAST
1516471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1526471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1536471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
1545b95f94cSJames Morse	select GENERIC_CPU_DEVICES
15561dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1566471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
15727d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1586471b825SIngo Molnar	select GENERIC_IOMAP
159c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1600fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
161ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1626471b825SIngo Molnar	select GENERIC_IRQ_PROBE
163c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1646471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1656471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1662ae27137SSteven Price	select GENERIC_PTDUMP
1676471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1686471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1697ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
170550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
1716ca297d4SPeter Zijlstra	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
17217e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1737edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
174fcbfe812SNiklas Schnelle	select HAS_IOPORT
1756471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1766471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1772a19be61SVlastimil Babka	select HAVE_ALIGNED_STRUCT_PAGE
1786471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1796471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
180eed1fceeSSong Liu	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
1816471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
182b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
183d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1840609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1851dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1864ca8cc8dSAlexander Potapenko	select HAVE_ARCH_KMSAN			if X86_64
1876471b825SIngo Molnar	select HAVE_ARCH_KGDB
1889e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1899e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1901b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
191271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1926471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
193f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
194afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1956471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1966471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
197a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
198b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1997677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
200e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
201fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
202c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
2032ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
2046471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
2056471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
20624a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER		if X86_64
20724a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
2086471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
20903f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
210280981d6SSathvika Vasireddy	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
2114ed308c4SSteven Rostedt (Google)	select HAVE_BUILDTIME_MCOUNT_SORT
2126471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
2139c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
214677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
21506aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
21602a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
217562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
218c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
219503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
22003f5781bSWang YanQing	select HAVE_EBPF_JIT
22158340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
2226630a8e5SChristoph Hellwig	select HAVE_EISA
2235f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
224*25176ad0SDavid Hildenbrand	select HAVE_GUP_FAST
225644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2266471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
227d938ba17SDonglin Peng	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
2284a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2296471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2306b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2310067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2326471b825SIngo Molnar	select HAVE_IOREMAP_PROT
233624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2346471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2354ab7674fSJosh Poimboeuf	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
2366471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2376471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2386471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2396471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2406471b825SIngo Molnar	select HAVE_KERNEL_LZO
2416471b825SIngo Molnar	select HAVE_KERNEL_XZ
242fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2436471b825SIngo Molnar	select HAVE_KPROBES
2446471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
245540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2466471b825SIngo Molnar	select HAVE_KRETPROBES
247f3a112c0SMasami Hiramatsu	select HAVE_RETHOOK
2486471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2490102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
250ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2519f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
252be37c98dSKalesh Singh	select HAVE_MOVE_PUD
25322102f45SJosh Poimboeuf	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
25442a0bb3fSPetr Mladek	select HAVE_NMI
255489e355bSJosh Poimboeuf	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
25603f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL			if X86_64
2576471b825SIngo Molnar	select HAVE_OPTPROBES
2585394f1e9SArnd Bergmann	select HAVE_PAGE_SIZE_4KB
2596471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2606471b825SIngo Molnar	select HAVE_PERF_EVENTS
261c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
26292e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
263eb01d42aSChristoph Hellwig	select HAVE_PCI
264c5e63197SJiri Olsa	select HAVE_PERF_REGS
265c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
266ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
2671e9fdf21SPeter Zijlstra	select MMU_GATHER_MERGE_VMAS
26800998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2696471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
27003f16cd0SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
2713c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
2727ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
273cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
274d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
27503f16cd0SJosh Poimboeuf	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
276e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
27703f16cd0SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
27899cf983cSMark Rutland	select HAVE_PREEMPT_DYNAMIC_CALL
279d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
28009498135SMiguel Ojeda	select HAVE_RUST			if X86_64
2816471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2825f3da8c0SJosh Poimboeuf	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
2836471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2847c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2857ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
2860c7ffa32SThomas Gleixner	select HOTPLUG_PARALLEL			if SMP && X86_64
28705736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
2880c7ffa32SThomas Gleixner	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
289c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
290c2508ec5SLinus Torvalds	select LOCK_MM_AND_FIND_VMA
2917ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
2927ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
29386596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2942eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
295625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2966471b825SIngo Molnar	select PERF_EVENTS
2973195ef59SPrarit Bhargava	select RTC_LIB
298d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2996471b825SIngo Molnar	select SPARSE_IRQ
3006471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
30115f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
3024aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
3034510bffbSMark Rutland	select TRACE_IRQFLAGS_NMI_SUPPORT
3046471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
3053b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
3060c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
30750468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
308d49a0626SPeter Zijlstra	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
309d49a0626SPeter Zijlstra	select FUNCTION_ALIGNMENT_4B
3109e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
311ceea991aSJiri Olsa	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
3127d8330a5SBalbir Singh
313ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
3143120e25eSJan Beulich	def_bool y
3153120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
316ba7e4d13SIngo Molnar
31751b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
31851b26adaSLinus Torvalds	string
31951b26adaSLinus Torvalds	default "elf32-i386" if X86_32
32051b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
32151b26adaSLinus Torvalds
3228d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
3233c2362e6SHarvey Harrison	def_bool y
3248d5fffb9SSam Ravnborg
3258d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
3263c2362e6SHarvey Harrison	def_bool y
3278d5fffb9SSam Ravnborg
3288d5fffb9SSam Ravnborgconfig MMU
3293c2362e6SHarvey Harrison	def_bool y
3308d5fffb9SSam Ravnborg
3319e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
3329e08f57dSDaniel Cashman	default 28 if 64BIT
3339e08f57dSDaniel Cashman	default 8
3349e08f57dSDaniel Cashman
3359e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3369e08f57dSDaniel Cashman	default 32 if 64BIT
3379e08f57dSDaniel Cashman	default 16
3389e08f57dSDaniel Cashman
3399e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3409e08f57dSDaniel Cashman	default 8
3419e08f57dSDaniel Cashman
3429e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3439e08f57dSDaniel Cashman	default 16
3449e08f57dSDaniel Cashman
3458d5fffb9SSam Ravnborgconfig SBUS
3468d5fffb9SSam Ravnborg	bool
3478d5fffb9SSam Ravnborg
3488d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3493120e25eSJan Beulich	def_bool y
3503120e25eSJan Beulich	depends on ISA_DMA_API
3518d5fffb9SSam Ravnborg
352d911c67eSAlexander Potapenkoconfig GENERIC_CSUM
353d911c67eSAlexander Potapenko	bool
354d911c67eSAlexander Potapenko	default y if KMSAN || KASAN
355d911c67eSAlexander Potapenko
3568d5fffb9SSam Ravnborgconfig GENERIC_BUG
3573c2362e6SHarvey Harrison	def_bool y
3588d5fffb9SSam Ravnborg	depends on BUG
359b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
360b93a531eSJan Beulich
361b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
362b93a531eSJan Beulich	bool
3638d5fffb9SSam Ravnborg
3648d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3653120e25eSJan Beulich	def_bool y
3663120e25eSJan Beulich	depends on ISA_DMA_API
3678d5fffb9SSam Ravnborg
3681032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3691032c0baSSam Ravnborg	def_bool y
3701032c0baSSam Ravnborg
3719a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3729a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3738d5fffb9SSam Ravnborg
374801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
375801e4062SJohannes Berg	def_bool y
376801e4062SJohannes Berg
377f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
378f4cb5700SJohannes Berg	def_bool y
379f4cb5700SJohannes Berg
3808d5fffb9SSam Ravnborgconfig AUDIT_ARCH
381e0fd24a3SJan Beulich	def_bool y if X86_64
3828d5fffb9SSam Ravnborg
383d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
384d6f2d75aSAndrey Ryabinin	hex
385d6f2d75aSAndrey Ryabinin	depends on KASAN
386d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
387d6f2d75aSAndrey Ryabinin
38869575d38SShane Wangconfig HAVE_INTEL_TXT
38969575d38SShane Wang	def_bool y
3906ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
39169575d38SShane Wang
3926b0c3d44SSam Ravnborgconfig X86_64_SMP
3936b0c3d44SSam Ravnborg	def_bool y
3946b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3956b0c3d44SSam Ravnborg
3962b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3972b144498SSrikar Dronamraju	def_bool y
3982b144498SSrikar Dronamraju
399d20642f0SRob Herringconfig FIX_EARLYCON_MEM
400d20642f0SRob Herring	def_bool y
401d20642f0SRob Herring
40294d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
40394d49eb3SKirill A. Shutemov	bool
40494d49eb3SKirill A. Shutemov
40598233368SKirill A. Shutemovconfig PGTABLE_LEVELS
40698233368SKirill A. Shutemov	int
40777ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
40898233368SKirill A. Shutemov	default 4 if X86_64
40998233368SKirill A. Shutemov	default 3 if X86_PAE
41098233368SKirill A. Shutemov	default 2
41198233368SKirill A. Shutemov
4122a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
4132a61f474SMasahiro Yamada	bool
4141b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
4151b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
4162a61f474SMasahiro Yamada	help
4172a61f474SMasahiro Yamada	  We have to make sure stack protector is unconditionally disabled if
4183fb0fdb3SAndy Lutomirski	  the compiler produces broken code or if it does not let us control
4193fb0fdb3SAndy Lutomirski	  the segment on 32-bit kernels.
4202a61f474SMasahiro Yamada
421506f1d07SSam Ravnborgmenu "Processor type and features"
422506f1d07SSam Ravnborg
423506f1d07SSam Ravnborgconfig SMP
424506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
425a7f7f624SMasahiro Yamada	help
426506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4274a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4284a474157SRobert Graffham	  than one CPU, say Y.
429506f1d07SSam Ravnborg
4304a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
431506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
432506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4334a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
434506f1d07SSam Ravnborg	  will run faster if you say N here.
435506f1d07SSam Ravnborg
436506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
437506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
438506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
439506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
440506f1d07SSam Ravnborg
441506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
442506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
443506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
444506f1d07SSam Ravnborg
445ff61f079SJonathan Corbet	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
4464f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
447506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
448506f1d07SSam Ravnborg
449506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
450506f1d07SSam Ravnborg
45106cd9a7dSYinghai Luconfig X86_X2APIC
45206cd9a7dSYinghai Lu	bool "Support x2apic"
45319e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
454a7f7f624SMasahiro Yamada	help
45506cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
45606cd9a7dSYinghai Lu
45706cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
45806cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
45906cd9a7dSYinghai Lu
460b8d1d163SDaniel Sneddon	  Some Intel systems circa 2022 and later are locked into x2APIC mode
461b8d1d163SDaniel Sneddon	  and can not fall back to the legacy APIC modes if SGX or TDX are
462e3998434SMateusz Jończyk	  enabled in the BIOS. They will boot with very reduced functionality
463e3998434SMateusz Jończyk	  without enabling this option.
464b8d1d163SDaniel Sneddon
46506cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
46606cd9a7dSYinghai Lu
4676695c85bSYinghai Luconfig X86_MPPARSE
4684590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4697a527688SJan Beulich	default y
4705ab74722SIngo Molnar	depends on X86_LOCAL_APIC
471a7f7f624SMasahiro Yamada	help
4726695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4736695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4746695c85bSYinghai Lu
475e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
476e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4776fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
47859fe5a77SThomas Gleixner	select KERNFS
479e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
48078e99b4aSFenghua Yu	help
481e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4826fe07ce3SBabu Moger
4836fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4846fe07ce3SBabu Moger	  usage by the CPU.
4856fe07ce3SBabu Moger
4866fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4876fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4886fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4896fe07ce3SBabu Moger
4906fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4916fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4926fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
49378e99b4aSFenghua Yu
49478e99b4aSFenghua Yu	  Say N if unsure.
49578e99b4aSFenghua Yu
4962cce9591SH. Peter Anvin (Intel)config X86_FRED
4972cce9591SH. Peter Anvin (Intel)	bool "Flexible Return and Event Delivery"
4982cce9591SH. Peter Anvin (Intel)	depends on X86_64
4992cce9591SH. Peter Anvin (Intel)	help
5002cce9591SH. Peter Anvin (Intel)	  When enabled, try to use Flexible Return and Event Delivery
5012cce9591SH. Peter Anvin (Intel)	  instead of the legacy SYSCALL/SYSENTER/IDT architecture for
5022cce9591SH. Peter Anvin (Intel)	  ring transitions and exception/interrupt handling if the
5032cce9591SH. Peter Anvin (Intel)	  system supports.
5042cce9591SH. Peter Anvin (Intel)
5058425091fSRavikiran G Thirumalaiif X86_32
506a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
507a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
508a0d0bb4dSRandy Dunlap	depends on SMP
509a7f7f624SMasahiro Yamada	help
510e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
511a0d0bb4dSRandy Dunlap
512c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
513c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
514c5c606d9SRavikiran G Thirumalai	default y
515a7f7f624SMasahiro Yamada	help
51606ac8346SIngo Molnar	  If you disable this option then the kernel will only support
51706ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
51806ac8346SIngo Molnar	  systems out there.)
51906ac8346SIngo Molnar
5208425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5218425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
522cb7b8023SBen Hutchings		Goldfish (Android emulator)
5238425091fSRavikiran G Thirumalai		AMD Elan
5248425091fSRavikiran G Thirumalai		RDC R-321x SoC
5258425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
52683125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5273f4110a4SThomas Gleixner		Moorestown MID devices
52806ac8346SIngo Molnar
52906ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
53006ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
531758cd94aSJuerg Haefligerendif # X86_32
53206ac8346SIngo Molnar
5338425091fSRavikiran G Thirumalaiif X86_64
5348425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5358425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5368425091fSRavikiran G Thirumalai	default y
537a7f7f624SMasahiro Yamada	help
5388425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5398425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5408425091fSRavikiran G Thirumalai	  systems out there.)
5418425091fSRavikiran G Thirumalai
5428425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5438425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
54444b111b5SSteffen Persvold		Numascale NumaChip
5458425091fSRavikiran G Thirumalai		ScaleMP vSMP
5468425091fSRavikiran G Thirumalai		SGI Ultraviolet
5478425091fSRavikiran G Thirumalai
5488425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5498425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
550758cd94aSJuerg Haefligerendif # X86_64
551c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
552c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
55344b111b5SSteffen Persvoldconfig X86_NUMACHIP
55444b111b5SSteffen Persvold	bool "Numascale NumaChip"
55544b111b5SSteffen Persvold	depends on X86_64
55644b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
55744b111b5SSteffen Persvold	depends on NUMA
55844b111b5SSteffen Persvold	depends on SMP
55944b111b5SSteffen Persvold	depends on X86_X2APIC
560f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
561a7f7f624SMasahiro Yamada	help
56244b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
56344b111b5SSteffen Persvold	  enable more than ~168 cores.
56444b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
56503b48632SNick Piggin
5666a48565eSIngo Molnarconfig X86_VSMP
567c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5686276a074SBorislav Petkov	select HYPERVISOR_GUEST
5696a48565eSIngo Molnar	select PARAVIRT
5706a48565eSIngo Molnar	depends on X86_64 && PCI
571c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
572ead91d4bSShai Fultheim	depends on SMP
573a7f7f624SMasahiro Yamada	help
5746a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5756a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5766a48565eSIngo Molnar	  if you have one of these machines.
5776a48565eSIngo Molnar
578c5c606d9SRavikiran G Thirumalaiconfig X86_UV
579c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
580c5c606d9SRavikiran G Thirumalai	depends on X86_64
581c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
58254c28d29SJack Steiner	depends on NUMA
5831ecb4ae5SAndrew Morton	depends on EFI
584c2209ea5SIngo Molnar	depends on KEXEC_CORE
5859d6c26e7SSuresh Siddha	depends on X86_X2APIC
5861222e564SIngo Molnar	depends on PCI
587a7f7f624SMasahiro Yamada	help
588c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
589c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
590c5c606d9SRavikiran G Thirumalai
591c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
592c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
593506f1d07SSam Ravnborg
594ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
595ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
596cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
597a7f7f624SMasahiro Yamada	help
598ddd70cf9SJun Nakajima	  Enable support for the Goldfish virtual platform used primarily
599ddd70cf9SJun Nakajima	  for Android development. Unless you are building for the Android
600ddd70cf9SJun Nakajima	  Goldfish emulator say N here.
601ddd70cf9SJun Nakajima
602c751e17bSThomas Gleixnerconfig X86_INTEL_CE
603c751e17bSThomas Gleixner	bool "CE4100 TV platform"
604c751e17bSThomas Gleixner	depends on PCI
605c751e17bSThomas Gleixner	depends on PCI_GODIRECT
6066084a6e2SJiang Liu	depends on X86_IO_APIC
607c751e17bSThomas Gleixner	depends on X86_32
608c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
60937bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
610da6b737bSSebastian Andrzej Siewior	select OF
611da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
612a7f7f624SMasahiro Yamada	help
613c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
614c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
615c751e17bSThomas Gleixner	  boxes and media devices.
616c751e17bSThomas Gleixner
6174cb9b00fSDavid Cohenconfig X86_INTEL_MID
61843605ef1SAlan Cox	bool "Intel MID platform support"
61943605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
620edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6211ea7c673SAlan Cox	depends on PCI
6223fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6231ea7c673SAlan Cox	depends on X86_IO_APIC
6244cb9b00fSDavid Cohen	select I2C
6257c9c3a1eSAlan Cox	select DW_APB_TIMER
62654b34aa0SMika Westerberg	select INTEL_SCU_PCI
627a7f7f624SMasahiro Yamada	help
6284cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6294cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6304cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6311ea7c673SAlan Cox
6324cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6334cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
63443605ef1SAlan Cox
6358bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6368bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6378bbc2a13SBryan O'Donoghue	depends on X86_32
6388bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6398bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6408bbc2a13SBryan O'Donoghue	depends on X86_TSC
6418bbc2a13SBryan O'Donoghue	depends on PCI
6428bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6438bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6448bbc2a13SBryan O'Donoghue	select IOSF_MBI
6458bbc2a13SBryan O'Donoghue	select INTEL_IMR
6469ab6eb51SAndy Shevchenko	select COMMON_CLK
647a7f7f624SMasahiro Yamada	help
6488bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6498bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6508bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6518bbc2a13SBryan O'Donoghue
6523d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6533d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6545962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6553d48aab1SMika Westerberg	select COMMON_CLK
6560f531431SMathias Nyman	select PINCTRL
657eebb3e8dSAndy Shevchenko	select IOSF_MBI
658a7f7f624SMasahiro Yamada	help
6593d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6603d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6610f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6620f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6633d48aab1SMika Westerberg
66492082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
66592082a88SKen Xue	bool "AMD ACPI2Platform devices support"
66692082a88SKen Xue	depends on ACPI
66792082a88SKen Xue	select COMMON_CLK
66892082a88SKen Xue	select PINCTRL
669a7f7f624SMasahiro Yamada	help
67092082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
67192082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
67292082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
67392082a88SKen Xue	  implemented under PINCTRL subsystem.
67492082a88SKen Xue
675ced3ce76SDavid E. Boxconfig IOSF_MBI
676ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
677ced3ce76SDavid E. Box	depends on PCI
678a7f7f624SMasahiro Yamada	help
679ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
680ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
681ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
682ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
683ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
684ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
685ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
686ced3ce76SDavid E. Box	   - BayTrail
687ced3ce76SDavid E. Box	   - Braswell
688ced3ce76SDavid E. Box	   - Quark
689ced3ce76SDavid E. Box
690ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
691ced3ce76SDavid E. Box
692ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
693ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
694ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
695a7f7f624SMasahiro Yamada	help
696ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
697ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
698ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
699ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
700ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
701ed2226bdSDavid E. Box	  device they want to access.
702ed2226bdSDavid E. Box
703ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
704ed2226bdSDavid E. Box
705c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
706c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
707506f1d07SSam Ravnborg	depends on X86_32
708c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
709c5c606d9SRavikiran G Thirumalai	select M486
710c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
711a7f7f624SMasahiro Yamada	help
712c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
713c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
714c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
715c5c606d9SRavikiran G Thirumalai
716e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7179c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7189c398017SIngo Molnar	depends on X86_32 && SMP
719c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
720a7f7f624SMasahiro Yamada	help
721b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
722b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
723b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
724b5660ba7SH. Peter Anvin	  one and will fallback to default.
725d49c4288SYinghai Lu
726c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
727d49c4288SYinghai Lu
728d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7296fc108a0SJan Beulich	def_bool y
730d949f36fSLinus Torvalds	# MCE code calls memory_failure():
731d949f36fSLinus Torvalds	depends on X86_MCE
732d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
733d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
734d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
735d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
736d949f36fSLinus Torvalds
73783125a3aSAlessandro Rubiniconfig STA2X11
73883125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
73983125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
74083125a3aSAlessandro Rubini	select SWIOTLB
74183125a3aSAlessandro Rubini	select MFD_STA2X11
7420145071bSLinus Walleij	select GPIOLIB
743a7f7f624SMasahiro Yamada	help
74483125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
74583125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
74683125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
74783125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
74883125a3aSAlessandro Rubini	  standard PC machines.
74983125a3aSAlessandro Rubini
75082148d1dSShérabconfig X86_32_IRIS
75182148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
75282148d1dSShérab	depends on X86_32
753a7f7f624SMasahiro Yamada	help
75482148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
75582148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
75682148d1dSShérab	  needed to do so, which is what this module does at
75782148d1dSShérab	  kernel shutdown.
75882148d1dSShérab
75982148d1dSShérab	  This is only for Iris machines from EuroBraille.
76082148d1dSShérab
76182148d1dSShérab	  If unused, say N.
76282148d1dSShérab
763ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7643c2362e6SHarvey Harrison	def_bool y
7653c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
766a87d0914SKen Chen	depends on X86
767a7f7f624SMasahiro Yamada	help
768506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
769506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
770506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
771506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
772506f1d07SSam Ravnborg
773506f1d07SSam Ravnborg	  If in doubt, say "Y".
774506f1d07SSam Ravnborg
7756276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7766276a074SBorislav Petkov	bool "Linux guest support"
777a7f7f624SMasahiro Yamada	help
7786276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7796276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7806276a074SBorislav Petkov	  setup.
781506f1d07SSam Ravnborg
7826276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7836276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
784506f1d07SSam Ravnborg
7856276a074SBorislav Petkovif HYPERVISOR_GUEST
786506f1d07SSam Ravnborg
787e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
788e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
789a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
790a7f7f624SMasahiro Yamada	help
791e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
792e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
793e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
794e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
795e61bd94aSEduardo Pereira Habkost
796c00a280aSJuergen Grossconfig PARAVIRT_XXL
797c00a280aSJuergen Gross	bool
798c00a280aSJuergen Gross
7996276a074SBorislav Petkovconfig PARAVIRT_DEBUG
8006276a074SBorislav Petkov	bool "paravirt-ops debugging"
8016276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
802a7f7f624SMasahiro Yamada	help
8036276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
8046276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
8056276a074SBorislav Petkov
806b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
807b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8086ea30386SKees Cook	depends on PARAVIRT && SMP
809a7f7f624SMasahiro Yamada	help
810b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
811b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
812b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
813b4ecc126SJeremy Fitzhardinge
8144c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8154c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
816b4ecc126SJeremy Fitzhardinge
8174c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
818b4ecc126SJeremy Fitzhardinge
819ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
820ecca2502SZhao Yakui	def_bool n
821ecca2502SZhao Yakui
8226276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8236276a074SBorislav Petkov
8246276a074SBorislav Petkovconfig KVM_GUEST
8256276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8266276a074SBorislav Petkov	depends on PARAVIRT
8276276a074SBorislav Petkov	select PARAVIRT_CLOCK
828a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
829b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8306276a074SBorislav Petkov	default y
831a7f7f624SMasahiro Yamada	help
8326276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8336276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8346276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8356276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8366276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8376276a074SBorislav Petkov
838a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
839a1c4423bSMarcelo Tosatti	def_bool n
840a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
841a1c4423bSMarcelo Tosatti	help
842a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
843a1c4423bSMarcelo Tosatti
8447733607fSMaran Wilsonconfig PVH
8457733607fSMaran Wilson	bool "Support for running PVH guests"
846a7f7f624SMasahiro Yamada	help
8477733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8487733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8497733607fSMaran Wilson
8506276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8516276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8526276a074SBorislav Petkov	depends on PARAVIRT
853a7f7f624SMasahiro Yamada	help
8546276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8556276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8566276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8576276a074SBorislav Petkov	  that, there can be a small performance impact.
8586276a074SBorislav Petkov
8596276a074SBorislav Petkov	  If in doubt, say N here.
8606276a074SBorislav Petkov
8617af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8627af192c9SGerd Hoffmann	bool
8637af192c9SGerd Hoffmann
8644a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8654a362601SJan Kiszka	bool "Jailhouse non-root cell support"
866abde587bSArnd Bergmann	depends on X86_64 && PCI
86787e65d05SJan Kiszka	select X86_PM_TIMER
868a7f7f624SMasahiro Yamada	help
8694a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8704a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8714a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8724a362601SJan Kiszka
873ec7972c9SZhao Yakuiconfig ACRN_GUEST
874ec7972c9SZhao Yakui	bool "ACRN Guest support"
875ec7972c9SZhao Yakui	depends on X86_64
876498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
877ec7972c9SZhao Yakui	help
878ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
879ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
880ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
881ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
882ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
883ec7972c9SZhao Yakui
88459bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST
88559bd54a8SKuppuswamy Sathyanarayanan	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
88659bd54a8SKuppuswamy Sathyanarayanan	depends on X86_64 && CPU_SUP_INTEL
88759bd54a8SKuppuswamy Sathyanarayanan	depends on X86_X2APIC
88875d090fdSKirill A. Shutemov	depends on EFI_STUB
88941394e33SKirill A. Shutemov	select ARCH_HAS_CC_PLATFORM
890968b4931SKirill A. Shutemov	select X86_MEM_ENCRYPT
89177a512e3SSean Christopherson	select X86_MCE
89275d090fdSKirill A. Shutemov	select UNACCEPTED_MEMORY
89359bd54a8SKuppuswamy Sathyanarayanan	help
89459bd54a8SKuppuswamy Sathyanarayanan	  Support running as a guest under Intel TDX.  Without this support,
89559bd54a8SKuppuswamy Sathyanarayanan	  the guest kernel can not boot or run under TDX.
89659bd54a8SKuppuswamy Sathyanarayanan	  TDX includes memory encryption and integrity capabilities
89759bd54a8SKuppuswamy Sathyanarayanan	  which protect the confidentiality and integrity of guest
89859bd54a8SKuppuswamy Sathyanarayanan	  memory contents and CPU state. TDX guests are protected from
89959bd54a8SKuppuswamy Sathyanarayanan	  some attacks from the VMM.
90059bd54a8SKuppuswamy Sathyanarayanan
9016276a074SBorislav Petkovendif # HYPERVISOR_GUEST
90297349135SJeremy Fitzhardinge
903506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
904506f1d07SSam Ravnborg
905506f1d07SSam Ravnborgconfig HPET_TIMER
9063c2362e6SHarvey Harrison	def_bool X86_64
907506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
908a7f7f624SMasahiro Yamada	help
909506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
910506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
911506f1d07SSam Ravnborg	  present.
912506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
913506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
914506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
9154e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
9164e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
917506f1d07SSam Ravnborg
918506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
919506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
920506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
921506f1d07SSam Ravnborg
922506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
923506f1d07SSam Ravnborg
924506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9253c2362e6SHarvey Harrison	def_bool y
9263228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
927506f1d07SSam Ravnborg
9286a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
929506f1d07SSam Ravnborg# The code disables itself when not needed.
9307ae9392cSThomas Petazzoniconfig DMI
9317ae9392cSThomas Petazzoni	default y
932cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9336a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
934a7f7f624SMasahiro Yamada	help
9357ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9367ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9377ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9387ae9392cSThomas Petazzoni	  BIOS code.
9397ae9392cSThomas Petazzoni
940506f1d07SSam Ravnborgconfig GART_IOMMU
94138901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9422f9237d4SChristoph Hellwig	select DMA_OPS
943a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
944506f1d07SSam Ravnborg	select SWIOTLB
94523ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
946a7f7f624SMasahiro Yamada	help
947ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
948ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
949ced3c42cSIngo Molnar
950ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
951ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
952ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
953ced3c42cSIngo Molnar
954ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
955ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
956ced3c42cSIngo Molnar
957ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
958ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
959ced3c42cSIngo Molnar	  32-bit limited device.
960ced3c42cSIngo Molnar
961ced3c42cSIngo Molnar	  If unsure, say Y.
962506f1d07SSam Ravnborg
9638b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT
9648b766b0fSMichal Suchanek	bool
9658b766b0fSMichal Suchanek	help
9668b766b0fSMichal Suchanek	  If true, at least one selected framebuffer driver can take advantage
9678b766b0fSMichal Suchanek	  of VESA video modes set at an early boot stage via the vga= parameter.
9688b766b0fSMichal Suchanek
9691184dc2fSMike Travisconfig MAXSMP
970ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9716ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
97236f5101aSMike Travis	select CPUMASK_OFFSTACK
973a7f7f624SMasahiro Yamada	help
974ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9751184dc2fSMike Travis	  If unsure, say N.
976506f1d07SSam Ravnborg
977aec6487eSIngo Molnar#
978aec6487eSIngo Molnar# The maximum number of CPUs supported:
979aec6487eSIngo Molnar#
980aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
981aec6487eSIngo Molnar# and which can be configured interactively in the
982aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
983aec6487eSIngo Molnar#
984aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
985aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
986aec6487eSIngo Molnar#
987aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
988aec6487eSIngo Molnar#   interactive configuration. )
989aec6487eSIngo Molnar#
990a0d0bb4dSRandy Dunlap
991aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
992a0d0bb4dSRandy Dunlap	int
993aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
994a0d0bb4dSRandy Dunlap	default    1 if !SMP
995a0d0bb4dSRandy Dunlap	default    2
996a0d0bb4dSRandy Dunlap
997aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
998a0d0bb4dSRandy Dunlap	int
999a0d0bb4dSRandy Dunlap	depends on X86_32
1000aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
1001aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
1002a0d0bb4dSRandy Dunlap	default    1 if !SMP
1003a0d0bb4dSRandy Dunlap
1004aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
1005a0d0bb4dSRandy Dunlap	int
1006a0d0bb4dSRandy Dunlap	depends on X86_64
10071edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
10081edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
1009a0d0bb4dSRandy Dunlap	default    1 if !SMP
1010aec6487eSIngo Molnar
1011aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1012aec6487eSIngo Molnar	int
1013aec6487eSIngo Molnar	depends on X86_32
1014aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
1015aec6487eSIngo Molnar	default    8 if  SMP
1016aec6487eSIngo Molnar	default    1 if !SMP
1017aec6487eSIngo Molnar
1018aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1019aec6487eSIngo Molnar	int
1020aec6487eSIngo Molnar	depends on X86_64
1021a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1022a0d0bb4dSRandy Dunlap	default   64 if  SMP
1023aec6487eSIngo Molnar	default    1 if !SMP
1024a0d0bb4dSRandy Dunlap
1025506f1d07SSam Ravnborgconfig NR_CPUS
102636f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1027aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1028aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1029a7f7f624SMasahiro Yamada	help
1030506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1031bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1032cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1033506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1034506f1d07SSam Ravnborg
1035aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1036aec6487eSIngo Molnar	  to the kernel image.
1037506f1d07SSam Ravnborg
103866558b73STim Chenconfig SCHED_CLUSTER
103966558b73STim Chen	bool "Cluster scheduler support"
104066558b73STim Chen	depends on SMP
104166558b73STim Chen	default y
104266558b73STim Chen	help
104366558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
104466558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
104566558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
104666558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
104766558b73STim Chen	  busses.
104866558b73STim Chen
1049506f1d07SSam Ravnborgconfig SCHED_SMT
1050dbe73364SThomas Gleixner	def_bool y if SMP
1051506f1d07SSam Ravnborg
1052506f1d07SSam Ravnborgconfig SCHED_MC
10533c2362e6SHarvey Harrison	def_bool y
10543c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1055c8e56d20SBorislav Petkov	depends on SMP
1056a7f7f624SMasahiro Yamada	help
1057506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1058506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1059506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1060506f1d07SSam Ravnborg
1061de966cf4STim Chenconfig SCHED_MC_PRIO
1062de966cf4STim Chen	bool "CPU core priorities scheduler support"
10633598e577SMeng Li	depends on SCHED_MC
10643598e577SMeng Li	select X86_INTEL_PSTATE if CPU_SUP_INTEL
10653598e577SMeng Li	select X86_AMD_PSTATE if CPU_SUP_AMD && ACPI
10660a21fc12SIngo Molnar	select CPU_FREQ
1067de966cf4STim Chen	default y
1068a7f7f624SMasahiro Yamada	help
1069de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1070de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1071de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1072de966cf4STim Chen	  single threaded workloads) than others.
1073de966cf4STim Chen
1074de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1075de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1076de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1077de966cf4STim Chen	  overall system performance can be achieved.
1078de966cf4STim Chen
1079de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1080de966cf4STim Chen
1081de966cf4STim Chen	  If unsure say Y here.
10825e76b2abSTim Chen
108330b8b006SThomas Gleixnerconfig UP_LATE_INIT
108430b8b006SThomas Gleixner	def_bool y
1085ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
108630b8b006SThomas Gleixner
1087506f1d07SSam Ravnborgconfig X86_UP_APIC
108850849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
108950849eefSJan Beulich	default PCI_MSI
109038a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1091a7f7f624SMasahiro Yamada	help
1092506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1093506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1094506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1095506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1096506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1097506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1098506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1099506f1d07SSam Ravnborg	  lockups.
1100506f1d07SSam Ravnborg
1101506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1102506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1103506f1d07SSam Ravnborg	depends on X86_UP_APIC
1104a7f7f624SMasahiro Yamada	help
1105506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1106506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1107506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1108506f1d07SSam Ravnborg
1109506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1110506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1111506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1112506f1d07SSam Ravnborg
1113506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
11143c2362e6SHarvey Harrison	def_bool y
11150dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1116b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
1117506f1d07SSam Ravnborg
1118506f1d07SSam Ravnborgconfig X86_IO_APIC
1119b1da1e71SJan Beulich	def_bool y
1120b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1121506f1d07SSam Ravnborg
112241b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
112341b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
112441b9eb26SStefan Assmann	depends on X86_IO_APIC
1125a7f7f624SMasahiro Yamada	help
112641b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
112741b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
112841b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
112941b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
113041b9eb26SStefan Assmann
113141b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
113241b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
113341b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
113441b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
113541b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
113641b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
113741b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
113841b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
113941b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
114041b9eb26SStefan Assmann	  down (vital) interrupt lines.
114141b9eb26SStefan Assmann
114241b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
114341b9eb26SStefan Assmann	  increased on these systems.
114441b9eb26SStefan Assmann
1145506f1d07SSam Ravnborgconfig X86_MCE
1146bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1147648ed940SChen, Gong	select GENERIC_ALLOCATOR
1148e57dbaf7SBorislav Petkov	default y
1149a7f7f624SMasahiro Yamada	help
1150bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1151bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1152506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1153bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11544efc0670SAndi Kleen
11555de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11565de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11575de97c9fSTony Luck	depends on X86_MCE
1158a7f7f624SMasahiro Yamada	help
11595de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11605de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11615de97c9fSTony Luck	  rasdaemon solution.
11625de97c9fSTony Luck
1163506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11643c2362e6SHarvey Harrison	def_bool y
11653c2362e6SHarvey Harrison	prompt "Intel MCE features"
1166c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1167a7f7f624SMasahiro Yamada	help
1168506f1d07SSam Ravnborg	  Additional support for intel specific MCE features such as
1169506f1d07SSam Ravnborg	  the thermal monitor.
1170506f1d07SSam Ravnborg
1171506f1d07SSam Ravnborgconfig X86_MCE_AMD
11723c2362e6SHarvey Harrison	def_bool y
11733c2362e6SHarvey Harrison	prompt "AMD MCE features"
1174f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1175a7f7f624SMasahiro Yamada	help
1176506f1d07SSam Ravnborg	  Additional support for AMD specific MCE features such as
1177506f1d07SSam Ravnborg	  the DRAM Error Threshold.
1178506f1d07SSam Ravnborg
11794efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11806fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1181c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1182a7f7f624SMasahiro Yamada	help
11834efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11845065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11854efc0670SAndi Kleen	  line.
11864efc0670SAndi Kleen
1187b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1188b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11896fc108a0SJan Beulich	def_bool y
1190b2762686SAndi Kleen
1191ea149b36SAndi Kleenconfig X86_MCE_INJECT
1192bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1193ea149b36SAndi Kleen	tristate "Machine check injector support"
1194a7f7f624SMasahiro Yamada	help
1195ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1196ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1197ea149b36SAndi Kleen	  QA it is safe to say n.
1198ea149b36SAndi Kleen
119907dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1200e633c65aSKan Liang
12015aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
12021e642812SIngo Molnar	bool "Legacy VM86 support"
1203506f1d07SSam Ravnborg	depends on X86_32
1204a7f7f624SMasahiro Yamada	help
12055aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
12065aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
12075aef51c3SAndy Lutomirski
12085aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
12095aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
12105aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
12115aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
12125aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
12131e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
12141e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
12151e642812SIngo Molnar	  mode might be faster than emulation and you might want to
12161e642812SIngo Molnar	  enable this option.
12175aef51c3SAndy Lutomirski
12181e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
12191e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12201e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12211e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12225aef51c3SAndy Lutomirski
12231e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12241e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12255aef51c3SAndy Lutomirski
12261e642812SIngo Molnar	  If unsure, say N here.
12275aef51c3SAndy Lutomirski
12285aef51c3SAndy Lutomirskiconfig VM86
12295aef51c3SAndy Lutomirski	bool
12305aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
123134273f41SH. Peter Anvin
123234273f41SH. Peter Anvinconfig X86_16BIT
123334273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
123434273f41SH. Peter Anvin	default y
1235a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1236a7f7f624SMasahiro Yamada	help
123734273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
123834273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
123934273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
124034273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
124134273f41SH. Peter Anvin
124234273f41SH. Peter Anvinconfig X86_ESPFIX32
124334273f41SH. Peter Anvin	def_bool y
124434273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1245506f1d07SSam Ravnborg
1246197725deSH. Peter Anvinconfig X86_ESPFIX64
1247197725deSH. Peter Anvin	def_bool y
124834273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1249506f1d07SSam Ravnborg
12501ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12511ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12521ad83c85SAndy Lutomirski	default y
12531ad83c85SAndy Lutomirski	depends on X86_64
1254a7f7f624SMasahiro Yamada	help
12551ad83c85SAndy Lutomirski	  This enables emulation of the legacy vsyscall page.  Disabling
12561ad83c85SAndy Lutomirski	  it is roughly equivalent to booting with vsyscall=none, except
12571ad83c85SAndy Lutomirski	  that it will also disable the helpful warning if a program
12581ad83c85SAndy Lutomirski	  tries to use a vsyscall.  With this option set to N, offending
12591ad83c85SAndy Lutomirski	  programs will just segfault, citing addresses of the form
12601ad83c85SAndy Lutomirski	  0xffffffffff600?00.
12611ad83c85SAndy Lutomirski
12621ad83c85SAndy Lutomirski	  This option is required by many programs built before 2013, and
12631ad83c85SAndy Lutomirski	  care should be used even with newer programs if set to N.
12641ad83c85SAndy Lutomirski
12651ad83c85SAndy Lutomirski	  Disabling this option saves about 7K of kernel size and
12661ad83c85SAndy Lutomirski	  possibly 4K of additional runtime pagetable memory.
12671ad83c85SAndy Lutomirski
1268111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1269111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1270a24ca997SThomas Gleixner	default y
1271a7f7f624SMasahiro Yamada	help
1272111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1273111e7b15SThomas Gleixner	  for legacy applications.
1274111e7b15SThomas Gleixner
1275c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1276c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1277c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1278c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1279c8137aceSThomas Gleixner	  modules.
1280c8137aceSThomas Gleixner
1281c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1282c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1283a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1284a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1285c8137aceSThomas Gleixner
1286506f1d07SSam Ravnborgconfig TOSHIBA
1287506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1288506f1d07SSam Ravnborg	depends on X86_32
1289a7f7f624SMasahiro Yamada	help
1290506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1291506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1292506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1293506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1294506f1d07SSam Ravnborg
1295506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1296506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1297506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1298506f1d07SSam Ravnborg
1299506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1300506f1d07SSam Ravnborg	  Say N otherwise.
1301506f1d07SSam Ravnborg
1302506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
13039ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
13049ba16087SJan Beulich	depends on X86_32
1305a7f7f624SMasahiro Yamada	help
1306506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1307506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1308506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1309506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1310506f1d07SSam Ravnborg	  system.
1311506f1d07SSam Ravnborg
1312506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
13135e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1314506f1d07SSam Ravnborg
1315506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1316506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1317506f1d07SSam Ravnborg	  Say N otherwise.
1318506f1d07SSam Ravnborg
1319506f1d07SSam Ravnborgconfig MICROCODE
1320e6bcfdd7SThomas Gleixner	def_bool y
132180030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
132280cc9f10SPeter Oruba
1323fdbd4381SThomas Gleixnerconfig MICROCODE_INITRD32
1324fdbd4381SThomas Gleixner	def_bool y
1325fdbd4381SThomas Gleixner	depends on MICROCODE && X86_32 && BLK_DEV_INITRD
1326fdbd4381SThomas Gleixner
1327a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING
1328a77a94f8SBorislav Petkov	bool "Late microcode loading (DANGEROUS)"
1329c02f48e0SBorislav Petkov	default n
1330634ac23aSThomas Gleixner	depends on MICROCODE && SMP
1331a7f7f624SMasahiro Yamada	help
1332a77a94f8SBorislav Petkov	  Loading microcode late, when the system is up and executing instructions
1333a77a94f8SBorislav Petkov	  is a tricky business and should be avoided if possible. Just the sequence
1334a77a94f8SBorislav Petkov	  of synchronizing all cores and SMT threads is one fragile dance which does
1335a77a94f8SBorislav Petkov	  not guarantee that cores might not softlock after the loading. Therefore,
13369407bda8SThomas Gleixner	  use this at your own risk. Late loading taints the kernel unless the
13379407bda8SThomas Gleixner	  microcode header indicates that it is safe for late loading via the
13389407bda8SThomas Gleixner	  minimal revision check. This minimal revision check can be enforced on
13399407bda8SThomas Gleixner	  the kernel command line with "microcode.minrev=Y".
13409407bda8SThomas Gleixner
13419407bda8SThomas Gleixnerconfig MICROCODE_LATE_FORCE_MINREV
13429407bda8SThomas Gleixner	bool "Enforce late microcode loading minimal revision check"
13439407bda8SThomas Gleixner	default n
13449407bda8SThomas Gleixner	depends on MICROCODE_LATE_LOADING
13459407bda8SThomas Gleixner	help
13469407bda8SThomas Gleixner	  To prevent that users load microcode late which modifies already
13479407bda8SThomas Gleixner	  in use features, newer microcode patches have a minimum revision field
13489407bda8SThomas Gleixner	  in the microcode header, which tells the kernel which minimum
13499407bda8SThomas Gleixner	  revision must be active in the CPU to safely load that new microcode
13509407bda8SThomas Gleixner	  late into the running system. If disabled the check will not
13519407bda8SThomas Gleixner	  be enforced but the kernel will be tainted when the minimal
13529407bda8SThomas Gleixner	  revision check fails.
13539407bda8SThomas Gleixner
13549407bda8SThomas Gleixner	  This minimal revision check can also be controlled via the
13559407bda8SThomas Gleixner	  "microcode.minrev" parameter on the kernel command line.
13569407bda8SThomas Gleixner
13579407bda8SThomas Gleixner	  If unsure say Y.
1358506f1d07SSam Ravnborg
1359506f1d07SSam Ravnborgconfig X86_MSR
1360506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1361a7f7f624SMasahiro Yamada	help
1362506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1363506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1364506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1365506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1366506f1d07SSam Ravnborg	  systems.
1367506f1d07SSam Ravnborg
1368506f1d07SSam Ravnborgconfig X86_CPUID
1369506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1370a7f7f624SMasahiro Yamada	help
1371506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1372506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1373506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1374506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1375506f1d07SSam Ravnborg
1376506f1d07SSam Ravnborgchoice
1377506f1d07SSam Ravnborg	prompt "High Memory Support"
13786fc108a0SJan Beulich	default HIGHMEM4G
1379506f1d07SSam Ravnborg	depends on X86_32
1380506f1d07SSam Ravnborg
1381506f1d07SSam Ravnborgconfig NOHIGHMEM
1382506f1d07SSam Ravnborg	bool "off"
1383a7f7f624SMasahiro Yamada	help
1384506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1385506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1386506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1387506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1388506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1389506f1d07SSam Ravnborg	  "high memory".
1390506f1d07SSam Ravnborg
1391506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1392506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1393506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1394506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1395506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1396506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1397506f1d07SSam Ravnborg	  possible.
1398506f1d07SSam Ravnborg
1399506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1400506f1d07SSam Ravnborg	  answer "4GB" here.
1401506f1d07SSam Ravnborg
1402506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1403506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1404506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1405506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1406506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1407506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1408506f1d07SSam Ravnborg
1409506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1410506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1411506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1412506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1413506f1d07SSam Ravnborg	  kernel at boot time.)
1414506f1d07SSam Ravnborg
1415506f1d07SSam Ravnborg	  If unsure, say "off".
1416506f1d07SSam Ravnborg
1417506f1d07SSam Ravnborgconfig HIGHMEM4G
1418506f1d07SSam Ravnborg	bool "4GB"
1419a7f7f624SMasahiro Yamada	help
1420506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1421506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1422506f1d07SSam Ravnborg
1423506f1d07SSam Ravnborgconfig HIGHMEM64G
1424506f1d07SSam Ravnborg	bool "64GB"
142588a2b4edSArnd Bergmann	depends on X86_HAVE_PAE
1426506f1d07SSam Ravnborg	select X86_PAE
1427a7f7f624SMasahiro Yamada	help
1428506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1429506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1430506f1d07SSam Ravnborg
1431506f1d07SSam Ravnborgendchoice
1432506f1d07SSam Ravnborg
1433506f1d07SSam Ravnborgchoice
14346a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1435506f1d07SSam Ravnborg	default VMSPLIT_3G
1436506f1d07SSam Ravnborg	depends on X86_32
1437a7f7f624SMasahiro Yamada	help
1438506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1439506f1d07SSam Ravnborg
1440506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1441506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1442506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1443506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1444506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1445506f1d07SSam Ravnborg	  available to user programs, making the address space there
1446506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1447506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1448506f1d07SSam Ravnborg	  kernel modules.
1449506f1d07SSam Ravnborg
1450506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1451506f1d07SSam Ravnborg	  option alone!
1452506f1d07SSam Ravnborg
1453506f1d07SSam Ravnborg	config VMSPLIT_3G
1454506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1455506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1456506f1d07SSam Ravnborg		depends on !X86_PAE
1457506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1458506f1d07SSam Ravnborg	config VMSPLIT_2G
1459506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1460506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1461506f1d07SSam Ravnborg		depends on !X86_PAE
1462506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1463506f1d07SSam Ravnborg	config VMSPLIT_1G
1464506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1465506f1d07SSam Ravnborgendchoice
1466506f1d07SSam Ravnborg
1467506f1d07SSam Ravnborgconfig PAGE_OFFSET
1468506f1d07SSam Ravnborg	hex
1469506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1470506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1471506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1472506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1473506f1d07SSam Ravnborg	default 0xC0000000
1474506f1d07SSam Ravnborg	depends on X86_32
1475506f1d07SSam Ravnborg
1476506f1d07SSam Ravnborgconfig HIGHMEM
14773c2362e6SHarvey Harrison	def_bool y
1478506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1479506f1d07SSam Ravnborg
1480506f1d07SSam Ravnborgconfig X86_PAE
14819ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
148288a2b4edSArnd Bergmann	depends on X86_32 && X86_HAVE_PAE
1483d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14849d99c712SChristian Melki	select SWIOTLB
1485a7f7f624SMasahiro Yamada	help
1486506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1487506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1488506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1489506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1490506f1d07SSam Ravnborg
149177ef56e4SKirill A. Shutemovconfig X86_5LEVEL
149277ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
149318ec1eafSKirill A. Shutemov	default y
1494eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1495162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
149677ef56e4SKirill A. Shutemov	depends on X86_64
1497a7f7f624SMasahiro Yamada	help
149877ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149977ef56e4SKirill A. Shutemov	  up to 128 PiB of virtual address space and 4 PiB of
150077ef56e4SKirill A. Shutemov	  physical address space.
150177ef56e4SKirill A. Shutemov
150277ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
150377ef56e4SKirill A. Shutemov
15046657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15056657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
150677ef56e4SKirill A. Shutemov
1507ff61f079SJonathan Corbet	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
150877ef56e4SKirill A. Shutemov	  information.
150977ef56e4SKirill A. Shutemov
151077ef56e4SKirill A. Shutemov	  Say N if unsure.
151177ef56e4SKirill A. Shutemov
151210971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1513e5008abeSLuis R. Rodriguez	def_bool y
15142e1da13fSVlastimil Babka	depends on X86_64
1515a7f7f624SMasahiro Yamada	help
151610971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
151710971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
151810971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151910971ab2SIngo Molnar	  that we have them enabled.
15209e899816SNick Piggin
15215c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15225c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15235c280cf6SThomas Gleixner	depends on DEBUG_FS
1524a7f7f624SMasahiro Yamada	help
1525b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1526a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15275c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15285c280cf6SThomas Gleixner
152920f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT
153020f07a04SKirill A. Shutemov	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
153120f07a04SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
153220f07a04SKirill A. Shutemov	def_bool n
153320f07a04SKirill A. Shutemov
15347744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15357744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15367744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
15376c321179STom Lendacky	depends on EFI_STUB
153882fef0adSDavid Rientjes	select DMA_COHERENT_POOL
1539ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1540597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1541aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
154220f07a04SKirill A. Shutemov	select X86_MEM_ENCRYPT
15436c321179STom Lendacky	select UNACCEPTED_MEMORY
1544a7f7f624SMasahiro Yamada	help
15457744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15467744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15477744ccdbSTom Lendacky	  Encryption (SME).
15487744ccdbSTom Lendacky
1549506f1d07SSam Ravnborg# Common NUMA Features
1550506f1d07SSam Ravnborgconfig NUMA
1551e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1552506f1d07SSam Ravnborg	depends on SMP
1553b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1554b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15557ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
15560c436a58SSaurabh Sengar	select OF_NUMA if OF
1557a7f7f624SMasahiro Yamada	help
1558e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1559fd51b2d7SKOSAKI Motohiro
1560506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1561506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1562506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1563506f1d07SSam Ravnborg
1564c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1565fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1566fd51b2d7SKOSAKI Motohiro
1567b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15687cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1569fd51b2d7SKOSAKI Motohiro
1570fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1571506f1d07SSam Ravnborg
1572eec1d4faSHans Rosenfeldconfig AMD_NUMA
15733c2362e6SHarvey Harrison	def_bool y
15743c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15755da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1576a7f7f624SMasahiro Yamada	help
1577eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1578eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1579eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1580eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1581eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1582506f1d07SSam Ravnborg
1583506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15843c2362e6SHarvey Harrison	def_bool y
15853c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1586506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1587506f1d07SSam Ravnborg	select ACPI_NUMA
1588a7f7f624SMasahiro Yamada	help
1589506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1590506f1d07SSam Ravnborg
1591506f1d07SSam Ravnborgconfig NUMA_EMU
1592506f1d07SSam Ravnborg	bool "NUMA emulation"
15931b7e03efSTejun Heo	depends on NUMA
1594a7f7f624SMasahiro Yamada	help
1595506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1596506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1597506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1598506f1d07SSam Ravnborg
1599506f1d07SSam Ravnborgconfig NODES_SHIFT
1600d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
160151591e31SDavid Rientjes	range 1 10
160251591e31SDavid Rientjes	default "10" if MAXSMP
1603506f1d07SSam Ravnborg	default "6" if X86_64
1604506f1d07SSam Ravnborg	default "3"
1605a9ee6cf5SMike Rapoport	depends on NUMA
1606a7f7f624SMasahiro Yamada	help
16071184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1608692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1609506f1d07SSam Ravnborg
1610506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1611506f1d07SSam Ravnborg	def_bool y
16123b16651fSTejun Heo	depends on X86_32 && !NUMA
1613506f1d07SSam Ravnborg
1614506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1615506f1d07SSam Ravnborg	def_bool y
16166ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1617506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1618506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1619506f1d07SSam Ravnborg
16203b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16216ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16223b16651fSTejun Heo
1623506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1624506f1d07SSam Ravnborg	def_bool y
16254eda2bc3SDavid Hildenbrand	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1626506f1d07SSam Ravnborg
1627506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1628a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16295c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1630a0842b70SToshi Kani	help
1631a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1632cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1633a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1634506f1d07SSam Ravnborg
16353b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16363b16651fSTejun Heo	def_bool y
16373b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16383b16651fSTejun Heo
1639a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1640a29815a3SAvi Kivity	hex
1641a29815a3SAvi Kivity	default 0 if X86_32
1642a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1643a29815a3SAvi Kivity
16447a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16457a67832cSDan Williams	bool
16467a67832cSDan Williams
1647ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16487a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16499f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16509f53f9faSDan Williams	depends on BLK_DEV
16517a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16527b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16539f53f9faSDan Williams	select LIBNVDIMM
1654ec776ef6SChristoph Hellwig	help
1655ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1656ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1657ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1658ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1659ec776ef6SChristoph Hellwig
1660ec776ef6SChristoph Hellwig	  Say Y if unsure.
1661ec776ef6SChristoph Hellwig
1662506f1d07SSam Ravnborgconfig HIGHPTE
1663506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16646fc108a0SJan Beulich	depends on HIGHMEM
1665a7f7f624SMasahiro Yamada	help
1666506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1667506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1668506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1669506f1d07SSam Ravnborg	  entries in high memory.
1670506f1d07SSam Ravnborg
16719f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16729f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1673a7f7f624SMasahiro Yamada	help
16749f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16759f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16769f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16779f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16789f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16799f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16809f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16818c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16829f077871SJeremy Fitzhardinge
16839f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16849f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16859f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16869f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16879f077871SJeremy Fitzhardinge
16889f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16899f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16909f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16919f077871SJeremy Fitzhardinge	  memory.
16929f077871SJeremy Fitzhardinge
1693c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1694c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1695c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1696c885df50SJeremy Fitzhardinge	default y
1697a7f7f624SMasahiro Yamada	help
1698c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1699c885df50SJeremy Fitzhardinge	  on or off.
1700c885df50SJeremy Fitzhardinge
1701506f1d07SSam Ravnborgconfig MATH_EMULATION
1702506f1d07SSam Ravnborg	bool
1703a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
170487d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1705a7f7f624SMasahiro Yamada	help
1706506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1707506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1708506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1709506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1710506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1711506f1d07SSam Ravnborg	  coprocessor or this emulation.
1712506f1d07SSam Ravnborg
1713506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1714506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1715506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1716506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1717506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1718506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1719506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1720506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1721506f1d07SSam Ravnborg
1722506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1723506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1724506f1d07SSam Ravnborg
1725506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1726506f1d07SSam Ravnborg	  kernel, it won't hurt.
1727506f1d07SSam Ravnborg
1728506f1d07SSam Ravnborgconfig MTRR
17296fc108a0SJan Beulich	def_bool y
17306a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1731a7f7f624SMasahiro Yamada	help
1732506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1733506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1734506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1735506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1736506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1737506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1738506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1739506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1740506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1741506f1d07SSam Ravnborg
1742506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1743506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1744506f1d07SSam Ravnborg	  as well:
1745506f1d07SSam Ravnborg
1746506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1747506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1748506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1749506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1750506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1751506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1752506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1753506f1d07SSam Ravnborg
1754506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1755506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1756506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1757506f1d07SSam Ravnborg
1758506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1759506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1760506f1d07SSam Ravnborg
1761ff61f079SJonathan Corbet	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1762506f1d07SSam Ravnborg
176395ffa243SYinghai Luconfig MTRR_SANITIZER
17642ffb3501SYinghai Lu	def_bool y
176595ffa243SYinghai Lu	prompt "MTRR cleanup support"
176695ffa243SYinghai Lu	depends on MTRR
1767a7f7f624SMasahiro Yamada	help
1768aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1769aba3728cSThomas Gleixner	  add writeback entries.
177095ffa243SYinghai Lu
1771aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1772692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1773aba3728cSThomas Gleixner	  mtrr_chunk_size.
177495ffa243SYinghai Lu
17752ffb3501SYinghai Lu	  If unsure, say Y.
177695ffa243SYinghai Lu
177795ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1778f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1779f5098d62SYinghai Lu	range 0 1
1780f5098d62SYinghai Lu	default "0"
178195ffa243SYinghai Lu	depends on MTRR_SANITIZER
1782a7f7f624SMasahiro Yamada	help
1783f5098d62SYinghai Lu	  Enable mtrr cleanup default value
178495ffa243SYinghai Lu
178512031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
178612031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
178712031a62SYinghai Lu	range 0 7
178812031a62SYinghai Lu	default "1"
178912031a62SYinghai Lu	depends on MTRR_SANITIZER
1790a7f7f624SMasahiro Yamada	help
179112031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1792aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
179312031a62SYinghai Lu
17942e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
17956fc108a0SJan Beulich	def_bool y
17966a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
17972a8a2719SIngo Molnar	depends on MTRR
1798a7f7f624SMasahiro Yamada	help
17992e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1800042b78e4SVenki Pallipadi
18012e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18022e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18032e5d9c85Svenkatesh.pallipadi@intel.com
18042e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1805042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18062e5d9c85Svenkatesh.pallipadi@intel.com
18072e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18082e5d9c85Svenkatesh.pallipadi@intel.com
180946cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
181046cf98cdSVenkatesh Pallipadi	def_bool y
181146cf98cdSVenkatesh Pallipadi	depends on X86_PAT
181246cf98cdSVenkatesh Pallipadi
1813b971880fSBabu Mogerconfig X86_UMIP
1814796ebc81SRicardo Neri	def_bool y
1815b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1816a7f7f624SMasahiro Yamada	help
1817b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1818b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1819b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1820b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1821b971880fSBabu Moger	  information about the hardware state.
1822796ebc81SRicardo Neri
1823796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1824796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1825796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1826796ebc81SRicardo Neri	  results are dummy.
1827aa35f896SRicardo Neri
1828156ff4a5SPeter Zijlstraconfig CC_HAS_IBT
1829156ff4a5SPeter Zijlstra	# GCC >= 9 and binutils >= 2.29
1830156ff4a5SPeter Zijlstra	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1831156ff4a5SPeter Zijlstra	# Clang/LLVM >= 14
1832262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1833262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1834156ff4a5SPeter Zijlstra	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1835262448f3SNathan Chancellor		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1836156ff4a5SPeter Zijlstra		  $(as-instr,endbr64)
1837156ff4a5SPeter Zijlstra
183818e66b69SRick Edgecombeconfig X86_CET
183918e66b69SRick Edgecombe	def_bool n
184018e66b69SRick Edgecombe	help
184118e66b69SRick Edgecombe	  CET features configured (Shadow stack or IBT)
184218e66b69SRick Edgecombe
1843156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT
1844156ff4a5SPeter Zijlstra	prompt "Indirect Branch Tracking"
18454fd5f70cSKees Cook	def_bool y
184603f16cd0SJosh Poimboeuf	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1847f6a2c2b2SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1848f6a2c2b2SNathan Chancellor	depends on !LD_IS_LLD || LLD_VERSION >= 140000
184903f16cd0SJosh Poimboeuf	select OBJTOOL
185018e66b69SRick Edgecombe	select X86_CET
1851156ff4a5SPeter Zijlstra	help
1852156ff4a5SPeter Zijlstra	  Build the kernel with support for Indirect Branch Tracking, a
1853156ff4a5SPeter Zijlstra	  hardware support course-grain forward-edge Control Flow Integrity
1854156ff4a5SPeter Zijlstra	  protection. It enforces that all indirect calls must land on
1855156ff4a5SPeter Zijlstra	  an ENDBR instruction, as such, the compiler will instrument the
1856156ff4a5SPeter Zijlstra	  code with them to make this happen.
1857156ff4a5SPeter Zijlstra
1858ed53a0d9SPeter Zijlstra	  In addition to building the kernel with IBT, seal all functions that
18594cdfc11bSNur Hussein	  are not indirect call targets, avoiding them ever becoming one.
1860ed53a0d9SPeter Zijlstra
1861ed53a0d9SPeter Zijlstra	  This requires LTO like objtool runs and will slow down the build. It
1862ed53a0d9SPeter Zijlstra	  does significantly reduce the number of ENDBR instructions in the
1863ed53a0d9SPeter Zijlstra	  kernel image.
1864ed53a0d9SPeter Zijlstra
186535e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
186638f3e775SBabu Moger	prompt "Memory Protection Keys"
186735e97790SDave Hansen	def_bool y
1868284244a9SDave Hansen	# Note: only available in 64-bit mode
186938f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
187052c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
187152c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1872a7f7f624SMasahiro Yamada	help
1873284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1874284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1875284244a9SDave Hansen	  page tables when an application changes protection domains.
1876284244a9SDave Hansen
18771eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1878284244a9SDave Hansen
1879284244a9SDave Hansen	  If unsure, say y.
188035e97790SDave Hansen
1881db616173SMichal Hockochoice
1882db616173SMichal Hocko	prompt "TSX enable mode"
1883db616173SMichal Hocko	depends on CPU_SUP_INTEL
1884db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1885db616173SMichal Hocko	help
1886db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1887db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1888db616173SMichal Hocko	  can lead to a noticeable performance boost.
1889db616173SMichal Hocko
1890db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1891db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1892db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1893db616173SMichal Hocko
1894db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1895db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1896db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1897db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1898db616173SMichal Hocko	  for the particular machine.
1899db616173SMichal Hocko
1900db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1901db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1902db616173SMichal Hocko	  details.
1903db616173SMichal Hocko
1904db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1905db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1906db616173SMichal Hocko	  relevant.
1907db616173SMichal Hocko
1908db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1909db616173SMichal Hocko	bool "off"
1910db616173SMichal Hocko	help
1911db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1912db616173SMichal Hocko
1913db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1914db616173SMichal Hocko	bool "on"
1915db616173SMichal Hocko	help
1916db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1917db616173SMichal Hocko	  line parameter.
1918db616173SMichal Hocko
1919db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1920db616173SMichal Hocko	bool "auto"
1921db616173SMichal Hocko	help
1922db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1923db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1924db616173SMichal Hockoendchoice
1925db616173SMichal Hocko
1926e7e05452SSean Christophersonconfig X86_SGX
1927e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1928b8d1d163SDaniel Sneddon	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1929e7e05452SSean Christopherson	depends on CRYPTO=y
1930e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1931e7e05452SSean Christopherson	select MMU_NOTIFIER
1932901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
193340e0e784STony Luck	select XARRAY_MULTI
1934e7e05452SSean Christopherson	help
1935e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1936e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1937e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1938e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1939e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1940e7e05452SSean Christopherson	  hardware.
1941e7e05452SSean Christopherson
1942e7e05452SSean Christopherson	  If unsure, say N.
1943e7e05452SSean Christopherson
194418e66b69SRick Edgecombeconfig X86_USER_SHADOW_STACK
194518e66b69SRick Edgecombe	bool "X86 userspace shadow stack"
194618e66b69SRick Edgecombe	depends on AS_WRUSS
194718e66b69SRick Edgecombe	depends on X86_64
194818e66b69SRick Edgecombe	select ARCH_USES_HIGH_VMA_FLAGS
194918e66b69SRick Edgecombe	select X86_CET
195018e66b69SRick Edgecombe	help
195118e66b69SRick Edgecombe	  Shadow stack protection is a hardware feature that detects function
195218e66b69SRick Edgecombe	  return address corruption.  This helps mitigate ROP attacks.
195318e66b69SRick Edgecombe	  Applications must be enabled to use it, and old userspace does not
195418e66b69SRick Edgecombe	  get protection "for free".
195518e66b69SRick Edgecombe
195618e66b69SRick Edgecombe	  CPUs supporting shadow stacks were first released in 2020.
195718e66b69SRick Edgecombe
195854acee60SDave Hansen	  See Documentation/arch/x86/shstk.rst for more information.
195918e66b69SRick Edgecombe
196018e66b69SRick Edgecombe	  If unsure, say N.
196118e66b69SRick Edgecombe
1962c33621b4SKai Huangconfig INTEL_TDX_HOST
1963c33621b4SKai Huang	bool "Intel Trust Domain Extensions (TDX) host support"
1964c33621b4SKai Huang	depends on CPU_SUP_INTEL
1965c33621b4SKai Huang	depends on X86_64
1966c33621b4SKai Huang	depends on KVM_INTEL
19673115cabdSKai Huang	depends on X86_X2APIC
1968abe8dbabSKai Huang	select ARCH_KEEP_MEMBLOCK
1969ac3a2208SKai Huang	depends on CONTIG_ALLOC
1970cb8eb06dSDave Hansen	depends on !KEXEC_CORE
197183e1bdc9SKai Huang	depends on X86_MCE
1972c33621b4SKai Huang	help
1973c33621b4SKai Huang	  Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
1974c33621b4SKai Huang	  host and certain physical attacks.  This option enables necessary TDX
1975c33621b4SKai Huang	  support in the host kernel to run confidential VMs.
1976c33621b4SKai Huang
1977c33621b4SKai Huang	  If unsure, say N.
1978c33621b4SKai Huang
1979506f1d07SSam Ravnborgconfig EFI
19809ba16087SJan Beulich	bool "EFI runtime service support"
19815b83683fSHuang, Ying	depends on ACPI
1982f6ce5002SSergey Vlasov	select UCS2_STRING
1983022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19841ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
1985aba7e066SArd Biesheuvel	select EFI_RUNTIME_MAP if KEXEC_CORE
1986a7f7f624SMasahiro Yamada	help
19878b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1988506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1989506f1d07SSam Ravnborg
19908b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19918b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19928b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19938b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19948b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19958b2cb7a8SHuang, Ying	  platforms.
1996506f1d07SSam Ravnborg
1997291f3632SMatt Flemingconfig EFI_STUB
1998291f3632SMatt Fleming	bool "EFI stub support"
1999c6dbd3e5SPeter Zijlstra	depends on EFI
20007b2a583aSMatt Fleming	select RELOCATABLE
2001a7f7f624SMasahiro Yamada	help
2002291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
2003291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
2004291f3632SMatt Fleming
20054f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
20060c759662SMatt Fleming
2007cc3fdda2SArd Biesheuvelconfig EFI_HANDOVER_PROTOCOL
2008cc3fdda2SArd Biesheuvel	bool "EFI handover protocol (DEPRECATED)"
2009cc3fdda2SArd Biesheuvel	depends on EFI_STUB
2010cc3fdda2SArd Biesheuvel	default y
2011cc3fdda2SArd Biesheuvel	help
2012cc3fdda2SArd Biesheuvel	  Select this in order to include support for the deprecated EFI
2013cc3fdda2SArd Biesheuvel	  handover protocol, which defines alternative entry points into the
2014cc3fdda2SArd Biesheuvel	  EFI stub.  This is a practice that has no basis in the UEFI
2015cc3fdda2SArd Biesheuvel	  specification, and requires a priori knowledge on the part of the
2016cc3fdda2SArd Biesheuvel	  bootloader about Linux/x86 specific ways of passing the command line
2017cc3fdda2SArd Biesheuvel	  and initrd, and where in memory those assets may be loaded.
2018cc3fdda2SArd Biesheuvel
2019cc3fdda2SArd Biesheuvel	  If in doubt, say Y. Even though the corresponding support is not
2020cc3fdda2SArd Biesheuvel	  present in upstream GRUB or other bootloaders, most distros build
2021cc3fdda2SArd Biesheuvel	  GRUB with numerous downstream patches applied, and may rely on the
2022cc3fdda2SArd Biesheuvel	  handover protocol as as result.
2023cc3fdda2SArd Biesheuvel
20247d453eeeSMatt Flemingconfig EFI_MIXED
20257d453eeeSMatt Fleming	bool "EFI mixed-mode support"
20267d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
2027a7f7f624SMasahiro Yamada	help
20287d453eeeSMatt Fleming	  Enabling this feature allows a 64-bit kernel to be booted
20297d453eeeSMatt Fleming	  on a 32-bit firmware, provided that your CPU supports 64-bit
20307d453eeeSMatt Fleming	  mode.
20317d453eeeSMatt Fleming
20327d453eeeSMatt Fleming	  Note that it is not possible to boot a mixed-mode enabled
20337d453eeeSMatt Fleming	  kernel via the EFI boot stub - a bootloader that supports
20347d453eeeSMatt Fleming	  the EFI handover protocol must be used.
20357d453eeeSMatt Fleming
20367d453eeeSMatt Fleming	  If unsure, say N.
20377d453eeeSMatt Fleming
20384059ba65SArd Biesheuvelconfig EFI_FAKE_MEMMAP
20394059ba65SArd Biesheuvel	bool "Enable EFI fake memory map"
20404059ba65SArd Biesheuvel	depends on EFI
20414059ba65SArd Biesheuvel	help
20424059ba65SArd Biesheuvel	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
20434059ba65SArd Biesheuvel	  this parameter, you can add arbitrary attribute to specific memory
20444059ba65SArd Biesheuvel	  range by updating original (firmware provided) EFI memmap.  This is
20454059ba65SArd Biesheuvel	  useful for debugging of EFI memmap related feature, e.g., Address
20464059ba65SArd Biesheuvel	  Range Mirroring feature.
20474059ba65SArd Biesheuvel
20484059ba65SArd Biesheuvelconfig EFI_MAX_FAKE_MEM
20494059ba65SArd Biesheuvel	int "maximum allowable number of ranges in efi_fake_mem boot option"
20504059ba65SArd Biesheuvel	depends on EFI_FAKE_MEMMAP
20514059ba65SArd Biesheuvel	range 1 128
20524059ba65SArd Biesheuvel	default 8
20534059ba65SArd Biesheuvel	help
20544059ba65SArd Biesheuvel	  Maximum allowable number of ranges in efi_fake_mem boot option.
20554059ba65SArd Biesheuvel	  Ranges can be set up to this value using comma-separated list.
20564059ba65SArd Biesheuvel	  The default value is 8.
20574059ba65SArd Biesheuvel
20581fff234dSArd Biesheuvelconfig EFI_RUNTIME_MAP
20591fff234dSArd Biesheuvel	bool "Export EFI runtime maps to sysfs" if EXPERT
20601fff234dSArd Biesheuvel	depends on EFI
20611fff234dSArd Biesheuvel	help
20621fff234dSArd Biesheuvel	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
20631fff234dSArd Biesheuvel	  That memory map is required by the 2nd kernel to set up EFI virtual
20641fff234dSArd Biesheuvel	  mappings after kexec, but can also be used for debugging purposes.
20651fff234dSArd Biesheuvel
20661fff234dSArd Biesheuvel	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
20671fff234dSArd Biesheuvel
20688636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
2069506f1d07SSam Ravnborg
20706af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC
20716af51380SEric DeVolder	def_bool y
2072506f1d07SSam Ravnborg
20736af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_FILE
2074c1ad12eeSArnd Bergmann	def_bool X86_64
2075506f1d07SSam Ravnborg
20766af51380SEric DeVolderconfig ARCH_SELECTS_KEXEC_FILE
20776af51380SEric DeVolder	def_bool y
20786af51380SEric DeVolder	depends on KEXEC_FILE
2079b69a2afdSJonathan McDowell	select HAVE_IMA_KEXEC if IMA
208074ca317cSVivek Goyal
2081e6265fe7SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_PURGATORY
2082c1ad12eeSArnd Bergmann	def_bool y
2083b799a09fSAKASHI Takahiro
20846af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_SIG
20856af51380SEric DeVolder	def_bool y
208699d5cadfSJiri Bohac
20876af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_SIG_FORCE
20886af51380SEric DeVolder	def_bool y
208999d5cadfSJiri Bohac
20906af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
20916af51380SEric DeVolder	def_bool y
209299d5cadfSJiri Bohac
20936af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_JUMP
20946af51380SEric DeVolder	def_bool y
20958e7d8381SVivek Goyal
20966af51380SEric DeVolderconfig ARCH_SUPPORTS_CRASH_DUMP
20976af51380SEric DeVolder	def_bool X86_64 || (X86_32 && HIGHMEM)
20988e7d8381SVivek Goyal
2099ea53ad9cSEric DeVolderconfig ARCH_SUPPORTS_CRASH_HOTPLUG
2100ea53ad9cSEric DeVolder	def_bool y
21013ab83521SHuang Ying
21029c08a2a1SBaoquan Heconfig ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
210385fcde40SBaoquan He	def_bool CRASH_RESERVE
21049c08a2a1SBaoquan He
2105506f1d07SSam Ravnborgconfig PHYSICAL_START
21066a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2107ceefccc9SH. Peter Anvin	default "0x1000000"
2108a7f7f624SMasahiro Yamada	help
2109506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2110506f1d07SSam Ravnborg
211143b1d3e6SChris Koch	  If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage
211243b1d3e6SChris Koch	  will decompress itself to above physical address and run from there.
211343b1d3e6SChris Koch	  Otherwise, bzImage will run from the address where it has been loaded
211443b1d3e6SChris Koch	  by the boot loader. The only exception is if it is loaded below the
211543b1d3e6SChris Koch	  above physical address, in which case it will relocate itself there.
2116506f1d07SSam Ravnborg
2117506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2118506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2119506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2120506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2121506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2122506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2123506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2124506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2125506f1d07SSam Ravnborg
2126ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2127ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2128ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2129ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2130ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2131ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2132ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2133330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2134ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2135506f1d07SSam Ravnborg
2136506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2137506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2138506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2139506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2140506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2141506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2142506f1d07SSam Ravnborg	  line.
2143506f1d07SSam Ravnborg
2144506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2145506f1d07SSam Ravnborg
2146506f1d07SSam Ravnborgconfig RELOCATABLE
214726717808SH. Peter Anvin	bool "Build a relocatable kernel"
214826717808SH. Peter Anvin	default y
2149a7f7f624SMasahiro Yamada	help
2150506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2151506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2152506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2153506f1d07SSam Ravnborg	  but are discarded at runtime.
2154506f1d07SSam Ravnborg
2155506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2156506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2157506f1d07SSam Ravnborg	  kernel.
2158506f1d07SSam Ravnborg
2159506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2160506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21618ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2162506f1d07SSam Ravnborg
21638ab3820fSKees Cookconfig RANDOMIZE_BASE
2164e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21658ab3820fSKees Cook	depends on RELOCATABLE
21666807c846SIngo Molnar	default y
2167a7f7f624SMasahiro Yamada	help
2168e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2169e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2170e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2171e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2172e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2173e8581e3dSBaoquan He	  code internals.
2174e8581e3dSBaoquan He
2175ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2176ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2177ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2178ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2179ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2180ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2181ed9f007eSKees Cook
2182ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2183ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2184ed9f007eSKees Cook	  512MB (8 bits of entropy).
21858ab3820fSKees Cook
2186a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2187e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2188e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2189ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2190ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2191ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2192ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2193ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2194ed9f007eSKees Cook	  limited due to memory layouts.
2195e8581e3dSBaoquan He
21966807c846SIngo Molnar	  If unsure, say Y.
2197da2b6fb9SKees Cook
21988ab3820fSKees Cook# Relocation on x86 needs some additional build support
2199845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2200845adf72SH. Peter Anvin	def_bool y
22018ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2202845adf72SH. Peter Anvin
2203506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2204a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
22058ab3820fSKees Cook	default "0x200000"
2206a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2207a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2208a7f7f624SMasahiro Yamada	help
2209506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2210506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2211506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2212506f1d07SSam Ravnborg
2213506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2214506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2215506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2216506f1d07SSam Ravnborg
2217506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2218506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2219506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2220506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2221506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2222506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2223506f1d07SSam Ravnborg	  above alignment restrictions.
2224506f1d07SSam Ravnborg
2225a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2226a0215061SKees Cook	  this value must be a multiple of 0x200000.
2227a0215061SKees Cook
2228506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2229506f1d07SSam Ravnborg
2230eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2231eedb92abSKirill A. Shutemov	bool
2232a7f7f624SMasahiro Yamada	help
2233eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2234eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2235eedb92abSKirill A. Shutemov
22360483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22370483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22380483e1faSThomas Garnier	depends on X86_64
22390483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2240eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22410483e1faSThomas Garnier	default RANDOMIZE_BASE
2242a7f7f624SMasahiro Yamada	help
22430483e1faSThomas Garnier	  Randomizes the base virtual address of kernel memory sections
22440483e1faSThomas Garnier	  (physical memory mapping, vmalloc & vmemmap). This security feature
22450483e1faSThomas Garnier	  makes exploits relying on predictable memory locations less reliable.
22460483e1faSThomas Garnier
22470483e1faSThomas Garnier	  The order of allocations remains unchanged. Entropy is generated in
22480483e1faSThomas Garnier	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
22490483e1faSThomas Garnier	  configuration have in average 30,000 different possible virtual
22500483e1faSThomas Garnier	  addresses for each memory section.
22510483e1faSThomas Garnier
22526807c846SIngo Molnar	  If unsure, say Y.
22530483e1faSThomas Garnier
225490397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
225590397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
225690397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
225790397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
225890397a41SThomas Garnier	default "0x0"
225990397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
226090397a41SThomas Garnier	range 0x0 0x40
2261a7f7f624SMasahiro Yamada	help
226290397a41SThomas Garnier	  Define the padding in terabytes added to the existing physical
226390397a41SThomas Garnier	  memory size during kernel memory randomization. It is useful
226490397a41SThomas Garnier	  for memory hotplug support but reduces the entropy available for
226590397a41SThomas Garnier	  address randomization.
226690397a41SThomas Garnier
226790397a41SThomas Garnier	  If unsure, leave at the default value.
226890397a41SThomas Garnier
22696449dcb0SKirill A. Shutemovconfig ADDRESS_MASKING
22706449dcb0SKirill A. Shutemov	bool "Linear Address Masking support"
22716449dcb0SKirill A. Shutemov	depends on X86_64
22726449dcb0SKirill A. Shutemov	help
22736449dcb0SKirill A. Shutemov	  Linear Address Masking (LAM) modifies the checking that is applied
22746449dcb0SKirill A. Shutemov	  to 64-bit linear addresses, allowing software to use of the
22756449dcb0SKirill A. Shutemov	  untranslated address bits for metadata.
22766449dcb0SKirill A. Shutemov
22776449dcb0SKirill A. Shutemov	  The capability can be used for efficient address sanitizers (ASAN)
22786449dcb0SKirill A. Shutemov	  implementation and for optimizations in JITs.
22796449dcb0SKirill A. Shutemov
2280506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2281bebd024eSThomas Gleixner	def_bool y
228240b31360SStephen Rothwell	depends on SMP
2283506f1d07SSam Ravnborg
2284506f1d07SSam Ravnborgconfig COMPAT_VDSO
2285b0b49f26SAndy Lutomirski	def_bool n
2286b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2287953fee1dSIngo Molnar	depends on COMPAT_32
2288a7f7f624SMasahiro Yamada	help
2289b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2290b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2291b0b49f26SAndy Lutomirski	  indicated in its segment table.
2292e84446deSRandy Dunlap
2293b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2294b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2295b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2296b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2297b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2298506f1d07SSam Ravnborg
2299b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2300b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2301b0b49f26SAndy Lutomirski
2302b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2303b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2304b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2305b0b49f26SAndy Lutomirski
2306b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2307b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2308506f1d07SSam Ravnborg
23093dc33bd3SKees Cookchoice
23103dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23113dc33bd3SKees Cook	depends on X86_64
2312625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23133dc33bd3SKees Cook	help
23143dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23153dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23163dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23173dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23183dc33bd3SKees Cook
23193dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2320bf00745eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2321bf00745eSAndy Lutomirski	  is deprecated and can only be enabled using the kernel command
2322bf00745eSAndy Lutomirski	  line.
23233dc33bd3SKees Cook
23243dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23253dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23263dc33bd3SKees Cook	  to improve security.
23273dc33bd3SKees Cook
2328bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23293dc33bd3SKees Cook
2330bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2331bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2332bd49e16eSAndy Lutomirski		help
2333bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2334bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2335bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2336bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2337bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2338bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2339bd49e16eSAndy Lutomirski		  buffer.
23403dc33bd3SKees Cook
23413dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23423dc33bd3SKees Cook		bool "None"
23433dc33bd3SKees Cook		help
23443dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23453dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23463dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23473dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23483dc33bd3SKees Cook		  malicious userspace programs can be identified.
23493dc33bd3SKees Cook
23503dc33bd3SKees Cookendchoice
23513dc33bd3SKees Cook
2352516cbf37STim Birdconfig CMDLINE_BOOL
2353516cbf37STim Bird	bool "Built-in kernel command line"
2354a7f7f624SMasahiro Yamada	help
2355516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2356516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2357516cbf37STim Bird	  necessary or convenient to provide some or all of the
2358516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2359516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2360516cbf37STim Bird
2361516cbf37STim Bird	  To compile command line arguments into the kernel,
2362516cbf37STim Bird	  set this option to 'Y', then fill in the
236369711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2364516cbf37STim Bird
2365516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2366516cbf37STim Bird	  should leave this option set to 'N'.
2367516cbf37STim Bird
2368516cbf37STim Birdconfig CMDLINE
2369516cbf37STim Bird	string "Built-in kernel command string"
2370516cbf37STim Bird	depends on CMDLINE_BOOL
2371516cbf37STim Bird	default ""
2372a7f7f624SMasahiro Yamada	help
2373516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2374516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2375516cbf37STim Bird	  command line at boot time, it is appended to this string to
2376516cbf37STim Bird	  form the full kernel command line, when the system boots.
2377516cbf37STim Bird
2378516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2379516cbf37STim Bird	  change this behavior.
2380516cbf37STim Bird
2381516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2382516cbf37STim Bird	  by the boot loader) should specify the device for the root
2383516cbf37STim Bird	  file system.
2384516cbf37STim Bird
2385516cbf37STim Birdconfig CMDLINE_OVERRIDE
2386516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2387645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2388a7f7f624SMasahiro Yamada	help
2389516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2390516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2391516cbf37STim Bird
2392516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2393516cbf37STim Bird	  be set to 'N' under normal conditions.
2394516cbf37STim Bird
2395a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2396a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2397a5b9e5a2SAndy Lutomirski	default y
2398a7f7f624SMasahiro Yamada	help
2399a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2400a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2401a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2402a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2403a5b9e5a2SAndy Lutomirski	  threading libraries.
2404a5b9e5a2SAndy Lutomirski
2405a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2406a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2407a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2408a5b9e5a2SAndy Lutomirski
2409a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2410a5b9e5a2SAndy Lutomirski
24113aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24123aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24133aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24143aac3ebeSThomas Gleixner	help
24153aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24163aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24173aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24183aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24193aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24203aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24213aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24223aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24233aac3ebeSThomas Gleixner	  never get a signal delivered.
24243aac3ebeSThomas Gleixner
24253aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24263aac3ebeSThomas Gleixner
2427b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2428b700e7f0SSeth Jennings
2429506f1d07SSam Ravnborgendmenu
2430506f1d07SSam Ravnborg
24311ca3683cSUros Bizjakconfig CC_HAS_NAMED_AS
24321ca3683cSUros Bizjak	def_bool CC_IS_GCC && GCC_VERSION >= 120100
24331ca3683cSUros Bizjak
24341ca3683cSUros Bizjakconfig USE_X86_SEG_SUPPORT
24351ca3683cSUros Bizjak	def_bool y
2436e29aad08SUros Bizjak	depends on CC_HAS_NAMED_AS
2437e29aad08SUros Bizjak	#
2438e29aad08SUros Bizjak	# -fsanitize=kernel-address (KASAN) is at the moment incompatible
2439e29aad08SUros Bizjak	# with named address spaces - see GCC PR sanitizer/111736.
2440e29aad08SUros Bizjak	#
2441e29aad08SUros Bizjak	depends on !KASAN
2442b6540de9SUros Bizjak	# -fsanitize=thread (KCSAN) is also incompatible.
2443b6540de9SUros Bizjak	depends on !KCSAN
24441ca3683cSUros Bizjak
2445f43b9876SPeter Zijlstraconfig CC_HAS_SLS
2446f43b9876SPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
2447f43b9876SPeter Zijlstra
2448f43b9876SPeter Zijlstraconfig CC_HAS_RETURN_THUNK
2449f43b9876SPeter Zijlstra	def_bool $(cc-option,-mfunction-return=thunk-extern)
2450f43b9876SPeter Zijlstra
2451bea75b33SThomas Gleixnerconfig CC_HAS_ENTRY_PADDING
2452bea75b33SThomas Gleixner	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2453bea75b33SThomas Gleixner
2454bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_CFI
2455bea75b33SThomas Gleixner	int
2456bea75b33SThomas Gleixner	default 59 if FUNCTION_ALIGNMENT_64B
2457bea75b33SThomas Gleixner	default 27 if FUNCTION_ALIGNMENT_32B
2458bea75b33SThomas Gleixner	default 11 if FUNCTION_ALIGNMENT_16B
2459bea75b33SThomas Gleixner	default  3 if FUNCTION_ALIGNMENT_8B
2460bea75b33SThomas Gleixner	default  0
2461bea75b33SThomas Gleixner
2462bea75b33SThomas Gleixner# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2463bea75b33SThomas Gleixner# except Kconfig can't do arithmetic :/
2464bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_BYTES
2465bea75b33SThomas Gleixner	int
2466bea75b33SThomas Gleixner	default FUNCTION_PADDING_CFI if CFI_CLANG
2467bea75b33SThomas Gleixner	default FUNCTION_ALIGNMENT
2468bea75b33SThomas Gleixner
2469931ab636SPeter Zijlstraconfig CALL_PADDING
2470931ab636SPeter Zijlstra	def_bool n
2471931ab636SPeter Zijlstra	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2472931ab636SPeter Zijlstra	select FUNCTION_ALIGNMENT_16B
2473931ab636SPeter Zijlstra
2474931ab636SPeter Zijlstraconfig FINEIBT
2475931ab636SPeter Zijlstra	def_bool y
2476aefb2f2eSBreno Leitao	depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE
2477931ab636SPeter Zijlstra	select CALL_PADDING
2478931ab636SPeter Zijlstra
24798f7c0d8bSThomas Gleixnerconfig HAVE_CALL_THUNKS
24808f7c0d8bSThomas Gleixner	def_bool y
24810911b8c5SBreno Leitao	depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL
24828f7c0d8bSThomas Gleixner
24838f7c0d8bSThomas Gleixnerconfig CALL_THUNKS
24848f7c0d8bSThomas Gleixner	def_bool n
2485931ab636SPeter Zijlstra	select CALL_PADDING
24868f7c0d8bSThomas Gleixner
2487b341b20dSPeter Zijlstraconfig PREFIX_SYMBOLS
2488b341b20dSPeter Zijlstra	def_bool y
2489931ab636SPeter Zijlstra	depends on CALL_PADDING && !CFI_CLANG
2490b341b20dSPeter Zijlstra
2491f43b9876SPeter Zijlstramenuconfig SPECULATION_MITIGATIONS
2492f43b9876SPeter Zijlstra	bool "Mitigations for speculative execution vulnerabilities"
2493f43b9876SPeter Zijlstra	default y
2494f43b9876SPeter Zijlstra	help
2495f43b9876SPeter Zijlstra	  Say Y here to enable options which enable mitigations for
2496f43b9876SPeter Zijlstra	  speculative execution hardware vulnerabilities.
2497f43b9876SPeter Zijlstra
2498f43b9876SPeter Zijlstra	  If you say N, all mitigations will be disabled. You really
2499f43b9876SPeter Zijlstra	  should know what you are doing to say so.
2500f43b9876SPeter Zijlstra
2501f43b9876SPeter Zijlstraif SPECULATION_MITIGATIONS
2502f43b9876SPeter Zijlstra
2503ea4654e0SBreno Leitaoconfig MITIGATION_PAGE_TABLE_ISOLATION
2504f43b9876SPeter Zijlstra	bool "Remove the kernel mapping in user mode"
2505f43b9876SPeter Zijlstra	default y
2506f43b9876SPeter Zijlstra	depends on (X86_64 || X86_PAE)
2507f43b9876SPeter Zijlstra	help
2508f43b9876SPeter Zijlstra	  This feature reduces the number of hardware side channels by
2509f43b9876SPeter Zijlstra	  ensuring that the majority of kernel addresses are not mapped
2510f43b9876SPeter Zijlstra	  into userspace.
2511f43b9876SPeter Zijlstra
2512ff61f079SJonathan Corbet	  See Documentation/arch/x86/pti.rst for more details.
2513f43b9876SPeter Zijlstra
2514aefb2f2eSBreno Leitaoconfig MITIGATION_RETPOLINE
2515f43b9876SPeter Zijlstra	bool "Avoid speculative indirect branches in kernel"
2516f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2517f43b9876SPeter Zijlstra	default y
2518f43b9876SPeter Zijlstra	help
2519f43b9876SPeter Zijlstra	  Compile kernel with the retpoline compiler options to guard against
2520f43b9876SPeter Zijlstra	  kernel-to-user data leaks by avoiding speculative indirect
2521f43b9876SPeter Zijlstra	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2522f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2523f43b9876SPeter Zijlstra
25240911b8c5SBreno Leitaoconfig MITIGATION_RETHUNK
2525f43b9876SPeter Zijlstra	bool "Enable return-thunks"
2526aefb2f2eSBreno Leitao	depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK
2527f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2528b648ab48SBen Hutchings	default y if X86_64
2529f43b9876SPeter Zijlstra	help
2530f43b9876SPeter Zijlstra	  Compile the kernel with the return-thunks compiler option to guard
2531f43b9876SPeter Zijlstra	  against kernel-to-user data leaks by avoiding return speculation.
2532f43b9876SPeter Zijlstra	  Requires a compiler with -mfunction-return=thunk-extern
2533f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2534f43b9876SPeter Zijlstra
2535ac61d439SBreno Leitaoconfig MITIGATION_UNRET_ENTRY
2536f43b9876SPeter Zijlstra	bool "Enable UNRET on kernel entry"
25370911b8c5SBreno Leitao	depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64
2538f43b9876SPeter Zijlstra	default y
2539f43b9876SPeter Zijlstra	help
2540f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=unret mitigation.
2541f43b9876SPeter Zijlstra
25425fa31af3SBreno Leitaoconfig MITIGATION_CALL_DEPTH_TRACKING
254380e4c1cdSThomas Gleixner	bool "Mitigate RSB underflow with call depth tracking"
254480e4c1cdSThomas Gleixner	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
254580e4c1cdSThomas Gleixner	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
254680e4c1cdSThomas Gleixner	select CALL_THUNKS
254780e4c1cdSThomas Gleixner	default y
254880e4c1cdSThomas Gleixner	help
254980e4c1cdSThomas Gleixner	  Compile the kernel with call depth tracking to mitigate the Intel
255080e4c1cdSThomas Gleixner	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
255180e4c1cdSThomas Gleixner	  mitigation is off by default and needs to be enabled on the
255280e4c1cdSThomas Gleixner	  kernel command line via the retbleed=stuff option. For
255380e4c1cdSThomas Gleixner	  non-affected systems the overhead of this option is marginal as
255480e4c1cdSThomas Gleixner	  the call depth tracking is using run-time generated call thunks
255580e4c1cdSThomas Gleixner	  in a compiler generated padding area and call patching. This
255680e4c1cdSThomas Gleixner	  increases text size by ~5%. For non affected systems this space
255780e4c1cdSThomas Gleixner	  is unused. On affected SKL systems this results in a significant
255880e4c1cdSThomas Gleixner	  performance gain over the IBRS mitigation.
255980e4c1cdSThomas Gleixner
2560e81dc127SThomas Gleixnerconfig CALL_THUNKS_DEBUG
2561e81dc127SThomas Gleixner	bool "Enable call thunks and call depth tracking debugging"
25625fa31af3SBreno Leitao	depends on MITIGATION_CALL_DEPTH_TRACKING
2563e81dc127SThomas Gleixner	select FUNCTION_ALIGNMENT_32B
2564e81dc127SThomas Gleixner	default n
2565e81dc127SThomas Gleixner	help
2566e81dc127SThomas Gleixner	  Enable call/ret counters for imbalance detection and build in
2567e81dc127SThomas Gleixner	  a noisy dmesg about callthunks generation and call patching for
2568e81dc127SThomas Gleixner	  trouble shooting. The debug prints need to be enabled on the
2569e81dc127SThomas Gleixner	  kernel command line with 'debug-callthunks'.
257054628de6SRandy Dunlap	  Only enable this when you are debugging call thunks as this
257154628de6SRandy Dunlap	  creates a noticeable runtime overhead. If unsure say N.
257280e4c1cdSThomas Gleixner
2573e0b8fcfaSBreno Leitaoconfig MITIGATION_IBPB_ENTRY
2574f43b9876SPeter Zijlstra	bool "Enable IBPB on kernel entry"
2575b648ab48SBen Hutchings	depends on CPU_SUP_AMD && X86_64
2576f43b9876SPeter Zijlstra	default y
2577f43b9876SPeter Zijlstra	help
2578f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=ibpb mitigation.
2579f43b9876SPeter Zijlstra
25801da8d217SBreno Leitaoconfig MITIGATION_IBRS_ENTRY
2581f43b9876SPeter Zijlstra	bool "Enable IBRS on kernel entry"
2582b648ab48SBen Hutchings	depends on CPU_SUP_INTEL && X86_64
2583f43b9876SPeter Zijlstra	default y
2584f43b9876SPeter Zijlstra	help
2585f43b9876SPeter Zijlstra	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2586f43b9876SPeter Zijlstra	  This mitigates both spectre_v2 and retbleed at great cost to
2587f43b9876SPeter Zijlstra	  performance.
2588f43b9876SPeter Zijlstra
2589a033eec9SBreno Leitaoconfig MITIGATION_SRSO
2590fb3bd914SBorislav Petkov (AMD)	bool "Mitigate speculative RAS overflow on AMD"
25910911b8c5SBreno Leitao	depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK
2592fb3bd914SBorislav Petkov (AMD)	default y
2593fb3bd914SBorislav Petkov (AMD)	help
2594fb3bd914SBorislav Petkov (AMD)	  Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2595fb3bd914SBorislav Petkov (AMD)
25967b75782fSBreno Leitaoconfig MITIGATION_SLS
2597f43b9876SPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
2598f43b9876SPeter Zijlstra	depends on CC_HAS_SLS && X86_64
2599f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2600f43b9876SPeter Zijlstra	default n
2601f43b9876SPeter Zijlstra	help
2602f43b9876SPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
2603f43b9876SPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
2604f43b9876SPeter Zijlstra	  larger.
2605f43b9876SPeter Zijlstra
2606be83e809SBreno Leitaoconfig MITIGATION_GDS_FORCE
260753cf5797SDaniel Sneddon	bool "Force GDS Mitigation"
260853cf5797SDaniel Sneddon	depends on CPU_SUP_INTEL
260953cf5797SDaniel Sneddon	default n
261053cf5797SDaniel Sneddon	help
261153cf5797SDaniel Sneddon	  Gather Data Sampling (GDS) is a hardware vulnerability which allows
261253cf5797SDaniel Sneddon	  unprivileged speculative access to data which was previously stored in
261353cf5797SDaniel Sneddon	  vector registers.
261453cf5797SDaniel Sneddon
261553cf5797SDaniel Sneddon	  This option is equivalent to setting gather_data_sampling=force on the
261653cf5797SDaniel Sneddon	  command line. The microcode mitigation is used if present, otherwise
261753cf5797SDaniel Sneddon	  AVX is disabled as a mitigation. On affected systems that are missing
261853cf5797SDaniel Sneddon	  the microcode any userspace code that unconditionally uses AVX will
261953cf5797SDaniel Sneddon	  break with this option set.
262053cf5797SDaniel Sneddon
262153cf5797SDaniel Sneddon	  Setting this option on systems not vulnerable to GDS has no effect.
262253cf5797SDaniel Sneddon
262353cf5797SDaniel Sneddon	  If in doubt, say N.
262453cf5797SDaniel Sneddon
26258076fcdeSPawan Guptaconfig MITIGATION_RFDS
26268076fcdeSPawan Gupta	bool "RFDS Mitigation"
26278076fcdeSPawan Gupta	depends on CPU_SUP_INTEL
26288076fcdeSPawan Gupta	default y
26298076fcdeSPawan Gupta	help
26308076fcdeSPawan Gupta	  Enable mitigation for Register File Data Sampling (RFDS) by default.
26318076fcdeSPawan Gupta	  RFDS is a hardware vulnerability which affects Intel Atom CPUs. It
26328076fcdeSPawan Gupta	  allows unprivileged speculative access to stale data previously
26338076fcdeSPawan Gupta	  stored in floating point, vector and integer registers.
26348076fcdeSPawan Gupta	  See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>
26358076fcdeSPawan Gupta
26364f511739SJosh Poimboeufconfig MITIGATION_SPECTRE_BHI
26374f511739SJosh Poimboeuf	bool "Mitigate Spectre-BHB (Branch History Injection)"
2638ec9404e4SPawan Gupta	depends on CPU_SUP_INTEL
26394f511739SJosh Poimboeuf	default y
2640ec9404e4SPawan Gupta	help
2641ec9404e4SPawan Gupta	  Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
2642ec9404e4SPawan Gupta	  where the branch history buffer is poisoned to speculatively steer
2643ec9404e4SPawan Gupta	  indirect branches.
2644ec9404e4SPawan Gupta	  See <file:Documentation/admin-guide/hw-vuln/spectre.rst>
2645ec9404e4SPawan Gupta
2646f43b9876SPeter Zijlstraendif
2647f43b9876SPeter Zijlstra
26483072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
26493072e413SMichal Hocko	def_bool y
26505c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
26513072e413SMichal Hocko
2652da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2653e279b6c1SSam Ravnborg
2654e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
26553c2362e6SHarvey Harrison	def_bool y
265644556530SZhimin Gu	depends on HIBERNATION
2657e279b6c1SSam Ravnborg
2658e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2659e279b6c1SSam Ravnborg
2660e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2661e279b6c1SSam Ravnborg
2662a6b68076SAndi Kleenconfig X86_APM_BOOT
26636fc108a0SJan Beulich	def_bool y
2664282e5aabSPaul Bolle	depends on APM
2665a6b68076SAndi Kleen
2666e279b6c1SSam Ravnborgmenuconfig APM
2667e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2668efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2669a7f7f624SMasahiro Yamada	help
2670e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2671e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2672e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2673e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2674e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2675e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2676e279b6c1SSam Ravnborg
2677e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2678e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2679e279b6c1SSam Ravnborg
2680e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2681e279b6c1SSam Ravnborg	  machines with more than one CPU.
2682e279b6c1SSam Ravnborg
2683e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2684151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
26852dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2686e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2687e279b6c1SSam Ravnborg
2688e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2689e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2690e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2691e279b6c1SSam Ravnborg
2692e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2693e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2694e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2695e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2696e279b6c1SSam Ravnborg
2697e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2698e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2699e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2700e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2701e279b6c1SSam Ravnborg	  APM in your BIOS).
2702e279b6c1SSam Ravnborg
2703e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2704e279b6c1SSam Ravnborg	  "weird" problems:
2705e279b6c1SSam Ravnborg
2706e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2707e279b6c1SSam Ravnborg	  enabled.
27087987448fSStephen Kitt	  2) pass the "idle=poll" option to the kernel
2709e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2710e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2711e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2712e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2713e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2714e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2715e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2716e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2717e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2718e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2719e279b6c1SSam Ravnborg	  11) exchange RAM chips
2720e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2721e279b6c1SSam Ravnborg
2722e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2723e279b6c1SSam Ravnborg	  module will be called apm.
2724e279b6c1SSam Ravnborg
2725e279b6c1SSam Ravnborgif APM
2726e279b6c1SSam Ravnborg
2727e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2728e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2729a7f7f624SMasahiro Yamada	help
2730e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2731e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2732e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2733e279b6c1SSam Ravnborg
2734e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2735e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2736a7f7f624SMasahiro Yamada	help
2737e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2738e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2739e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2740e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2741e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2742e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2743e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2744e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2745e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2746e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2747e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2748e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2749e279b6c1SSam Ravnborg	  this feature.
2750e279b6c1SSam Ravnborg
2751e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2752dd8af076SLen Brown	depends on CPU_IDLE
2753e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2754a7f7f624SMasahiro Yamada	help
2755e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2756e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2757e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2758e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2759e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2760e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2761e279b6c1SSam Ravnborg	  this option does nothing.)
2762e279b6c1SSam Ravnborg
2763e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2764e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2765a7f7f624SMasahiro Yamada	help
2766e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2767e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2768e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2769e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2770e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2771e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2772e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2773e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2774e279b6c1SSam Ravnborg	  especially if you are using gpm.
2775e279b6c1SSam Ravnborg
2776e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2777e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2778a7f7f624SMasahiro Yamada	help
2779e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2780e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2781e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2782e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2783e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2784e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2785e279b6c1SSam Ravnborg
2786e279b6c1SSam Ravnborgendif # APM
2787e279b6c1SSam Ravnborg
2788bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2789e279b6c1SSam Ravnborg
2790e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2791e279b6c1SSam Ravnborg
279227471fdbSAndy Henroidsource "drivers/idle/Kconfig"
279327471fdbSAndy Henroid
2794e279b6c1SSam Ravnborgendmenu
2795e279b6c1SSam Ravnborg
2796e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2797e279b6c1SSam Ravnborg
2798e279b6c1SSam Ravnborgchoice
2799e279b6c1SSam Ravnborg	prompt "PCI access mode"
2800efefa6f6SIngo Molnar	depends on X86_32 && PCI
2801e279b6c1SSam Ravnborg	default PCI_GOANY
2802a7f7f624SMasahiro Yamada	help
2803e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2804e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2805e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2806e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2807e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2808e279b6c1SSam Ravnborg
2809e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2810e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2811e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2812e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2813e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2814e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2815e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2816e279b6c1SSam Ravnborg
2817e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2818e279b6c1SSam Ravnborg	bool "BIOS"
2819e279b6c1SSam Ravnborg
2820e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2821e279b6c1SSam Ravnborg	bool "MMConfig"
2822e279b6c1SSam Ravnborg
2823e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2824e279b6c1SSam Ravnborg	bool "Direct"
2825e279b6c1SSam Ravnborg
28263ef0e1f8SAndres Salomonconfig PCI_GOOLPC
282776fb6570SDaniel Drake	bool "OLPC XO-1"
28283ef0e1f8SAndres Salomon	depends on OLPC
28293ef0e1f8SAndres Salomon
28302bdd1b03SAndres Salomonconfig PCI_GOANY
28312bdd1b03SAndres Salomon	bool "Any"
28322bdd1b03SAndres Salomon
2833e279b6c1SSam Ravnborgendchoice
2834e279b6c1SSam Ravnborg
2835e279b6c1SSam Ravnborgconfig PCI_BIOS
28363c2362e6SHarvey Harrison	def_bool y
2837efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2838e279b6c1SSam Ravnborg
2839e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2840e279b6c1SSam Ravnborgconfig PCI_DIRECT
28413c2362e6SHarvey Harrison	def_bool y
28420aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2843e279b6c1SSam Ravnborg
2844e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2845b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2846b45c9f36SJan Kiszka	default y
28474590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2848b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2849e279b6c1SSam Ravnborg
28503ef0e1f8SAndres Salomonconfig PCI_OLPC
28512bdd1b03SAndres Salomon	def_bool y
28522bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
28533ef0e1f8SAndres Salomon
2854b5401a96SAlex Nixonconfig PCI_XEN
2855b5401a96SAlex Nixon	def_bool y
2856b5401a96SAlex Nixon	depends on PCI && XEN
2857b5401a96SAlex Nixon
28588364e1f8SJan Kiszkaconfig MMCONF_FAM10H
28598364e1f8SJan Kiszka	def_bool y
28608364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2861e279b6c1SSam Ravnborg
28623f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
28636a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
28646ea30386SKees Cook	depends on PCI
28653f6ea84aSIra W. Snyder	help
28663f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
28673f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
28683f6ea84aSIra W. Snyder	  not have ACPI.
28693f6ea84aSIra W. Snyder
287064a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
287164a5fed6SBjorn Helgaas	  is known to be incomplete.
287264a5fed6SBjorn Helgaas
287364a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
287464a5fed6SBjorn Helgaas
28753a495511SWilliam Breathitt Grayconfig ISA_BUS
287617a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
28773a495511SWilliam Breathitt Gray	help
287817a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
287917a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
288017a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
288117a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
288217a2a129SWilliam Breathitt Gray	  not have an ISA bus.
28833a495511SWilliam Breathitt Gray
28843a495511SWilliam Breathitt Gray	  If unsure, say N.
28853a495511SWilliam Breathitt Gray
28861c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2887e279b6c1SSam Ravnborgconfig ISA_DMA_API
28881c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
28891c00f016SDavid Rientjes	default y
28901c00f016SDavid Rientjes	help
28911c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
28921c00f016SDavid Rientjes	  If unsure, say Y.
2893e279b6c1SSam Ravnborg
289451e68d05SLinus Torvaldsif X86_32
289551e68d05SLinus Torvalds
2896e279b6c1SSam Ravnborgconfig ISA
2897e279b6c1SSam Ravnborg	bool "ISA support"
2898a7f7f624SMasahiro Yamada	help
2899e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2900e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2901e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2902e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2903e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2904e279b6c1SSam Ravnborg
2905e279b6c1SSam Ravnborgconfig SCx200
2906e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2907a7f7f624SMasahiro Yamada	help
2908e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2909e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2910e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2911e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2912e279b6c1SSam Ravnborg
2913e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2914e279b6c1SSam Ravnborg
2915e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2916e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2917592913ecSJohn Stultz	depends on SCx200
2918e279b6c1SSam Ravnborg	default y
2919a7f7f624SMasahiro Yamada	help
2920e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2921e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2922e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2923e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2924e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2925e279b6c1SSam Ravnborg
29263ef0e1f8SAndres Salomonconfig OLPC
29273ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
292854008979SThomas Gleixner	depends on !X86_PAE
29293c554946SAndres Salomon	select GPIOLIB
2930dc3119e7SThomas Gleixner	select OF
293145bb1674SDaniel Drake	select OF_PROMTREE
2932b4e51854SGrant Likely	select IRQ_DOMAIN
29330c3d931bSLubomir Rintel	select OLPC_EC
2934a7f7f624SMasahiro Yamada	help
29353ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
29363ef0e1f8SAndres Salomon	  XO hardware.
29373ef0e1f8SAndres Salomon
2938a3128588SDaniel Drakeconfig OLPC_XO1_PM
2939a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2940fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2941a7f7f624SMasahiro Yamada	help
294297c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2943bf1ebf00SDaniel Drake
2944cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2945cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2946cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2947a7f7f624SMasahiro Yamada	help
2948cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2949cfee9597SDaniel Drake	  programmable wakeup source.
2950cfee9597SDaniel Drake
29517feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
29527feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
295392e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2954ed8e47feSRandy Dunlap	depends on INPUT=y
2955d8d01a63SDaniel Drake	select POWER_SUPPLY
2956a7f7f624SMasahiro Yamada	help
29577feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
29587bc74b3dSDaniel Drake	   - EC-driven system wakeups
29597feda8e9SDaniel Drake	   - Power button
29607bc74b3dSDaniel Drake	   - Ebook switch
29612cf2baeaSDaniel Drake	   - Lid switch
2962e1040ac6SDaniel Drake	   - AC adapter status updates
2963e1040ac6SDaniel Drake	   - Battery status updates
29647feda8e9SDaniel Drake
2965a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2966a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2967d8d01a63SDaniel Drake	depends on OLPC && ACPI
2968d8d01a63SDaniel Drake	select POWER_SUPPLY
2969a7f7f624SMasahiro Yamada	help
2970a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2971a0f30f59SDaniel Drake	   - EC-driven system wakeups
2972a0f30f59SDaniel Drake	   - AC adapter status updates
2973a0f30f59SDaniel Drake	   - Battery status updates
2974e279b6c1SSam Ravnborg
2975d4f3e350SEd Wildgooseconfig ALIX
2976d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2977d4f3e350SEd Wildgoose	select GPIOLIB
2978a7f7f624SMasahiro Yamada	help
2979d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2980d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2981d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2982d4f3e350SEd Wildgoose	  get added here.
2983d4f3e350SEd Wildgoose
2984d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2985d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2986d4f3e350SEd Wildgoose
2987d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2988d4f3e350SEd Wildgoose
2989da4e3302SPhilip Prindevilleconfig NET5501
2990da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2991da4e3302SPhilip Prindeville	select GPIOLIB
2992a7f7f624SMasahiro Yamada	help
2993da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2994da4e3302SPhilip Prindeville
29953197059aSPhilip A. Prindevilleconfig GEOS
29963197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
29973197059aSPhilip A. Prindeville	select GPIOLIB
29983197059aSPhilip A. Prindeville	depends on DMI
2999a7f7f624SMasahiro Yamada	help
30003197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
30013197059aSPhilip A. Prindeville
30027d029125SVivien Didelotconfig TS5500
30037d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
30047d029125SVivien Didelot	depends on MELAN
30057d029125SVivien Didelot	select CHECK_SIGNATURE
30067d029125SVivien Didelot	select NEW_LEDS
30077d029125SVivien Didelot	select LEDS_CLASS
3008a7f7f624SMasahiro Yamada	help
30097d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
30107d029125SVivien Didelot
3011e279b6c1SSam Ravnborgendif # X86_32
3012e279b6c1SSam Ravnborg
301323ac4ae8SAndreas Herrmannconfig AMD_NB
3014e279b6c1SSam Ravnborg	def_bool y
30150e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
3016e279b6c1SSam Ravnborg
3017e279b6c1SSam Ravnborgendmenu
3018e279b6c1SSam Ravnborg
30191572497cSChristoph Hellwigmenu "Binary Emulations"
3020e279b6c1SSam Ravnborg
3021e279b6c1SSam Ravnborgconfig IA32_EMULATION
3022e279b6c1SSam Ravnborg	bool "IA32 Emulation"
3023e279b6c1SSam Ravnborg	depends on X86_64
302439f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
3025d1603990SRandy Dunlap	select BINFMT_ELF
302639f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
3027a7f7f624SMasahiro Yamada	help
30285fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
30295fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
30305fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
3031e279b6c1SSam Ravnborg
3032a11e0975SNikolay Borisovconfig IA32_EMULATION_DEFAULT_DISABLED
3033a11e0975SNikolay Borisov	bool "IA32 emulation disabled by default"
3034a11e0975SNikolay Borisov	default n
3035a11e0975SNikolay Borisov	depends on IA32_EMULATION
3036a11e0975SNikolay Borisov	help
3037a11e0975SNikolay Borisov	  Make IA32 emulation disabled by default. This prevents loading 32-bit
3038a11e0975SNikolay Borisov	  processes and access to 32-bit syscalls. If unsure, leave it to its
3039a11e0975SNikolay Borisov	  default value.
3040a11e0975SNikolay Borisov
304183a44a4fSMasahiro Yamadaconfig X86_X32_ABI
30426ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
30439b54050bSBrian Gerst	depends on X86_64
3044aaeed6ecSNathan Chancellor	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3045aaeed6ecSNathan Chancellor	# compressed debug sections to x86_x32 properly:
3046aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/514
3047aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/1141
3048aaeed6ecSNathan Chancellor	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3049a7f7f624SMasahiro Yamada	help
30505fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
30515fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
30525fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
30535fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
30545fd92e65SH. J. Lu
3055953fee1dSIngo Molnarconfig COMPAT_32
3056953fee1dSIngo Molnar	def_bool y
3057953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
3058953fee1dSIngo Molnar	select HAVE_UID16
3059953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
3060953fee1dSIngo Molnar
3061e279b6c1SSam Ravnborgconfig COMPAT
30623c2362e6SHarvey Harrison	def_bool y
306383a44a4fSMasahiro Yamada	depends on IA32_EMULATION || X86_X32_ABI
3064e279b6c1SSam Ravnborg
3065e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
30663120e25eSJan Beulich	def_bool y
3067a9251280SLinus Torvalds	depends on COMPAT
3068ee009e4aSDavid Howells
3069e279b6c1SSam Ravnborgendmenu
3070e279b6c1SSam Ravnborg
3071e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
3072e5beae16SKeith Packard	def_bool y
3073e5beae16SKeith Packard	depends on X86_32
3074e5beae16SKeith Packard
3075edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
30765e8ebd84SJason A. Donenfeld
30775e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
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