xref: /linux/arch/x86/Kconfig (revision 31daa34315d45d3fe77f2158d889d523d78852ea)
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
3175182022SPeter Xu	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
32d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
33d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
34f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3509230cbcSChristoph Hellwig	select SWIOTLB
367facdc42SAl Viro	select ARCH_HAS_ELFCORE_COMPAT
3763703f37SKefeng Wang	select ZONE_DMA32
3814e56fb2SMike Rapoport (IBM)	select EXECMEM if DYNAMIC_FTRACE
391032c0baSSam Ravnborg
40518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
41518049d9SSteven Rostedt (VMware)	def_bool y
42518049d9SSteven Rostedt (VMware)	depends on X86_32
43518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
44518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
45518049d9SSteven Rostedt (VMware)	help
46518049d9SSteven Rostedt (VMware)	  We keep the static function tracing (!DYNAMIC_FTRACE) around
47518049d9SSteven Rostedt (VMware)	  in order to test the non static function tracing in the
48518049d9SSteven Rostedt (VMware)	  generic code, as other architectures still use it. But we
49518049d9SSteven Rostedt (VMware)	  only need to keep it around for x86_64. No need to keep it
50518049d9SSteven Rostedt (VMware)	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
51d94e0685SIngo Molnar#
52d94e0685SIngo Molnar# Arch settings
53d94e0685SIngo Molnar#
54d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
55d94e0685SIngo Molnar#   ported to 32-bit as well. )
56d94e0685SIngo Molnar#
578d5fffb9SSam Ravnborgconfig X86
583c2362e6SHarvey Harrison	def_bool y
59c763ea26SIngo Molnar	#
60c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
61c763ea26SIngo Molnar	#
626471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
636e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
64a02f66bbSJames Morse	select ACPI_HOTPLUG_CPU			if ACPI_PROCESSOR && HOTPLUG_CPU
65942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
662a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
67fe42754bSSean Christopherson	select ARCH_CONFIGURES_CPU_MITIGATIONS
681f6d3a8fSMasami Hiramatsu	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
691e866974SAnshuman Khandual	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
705c11f00bSDavid Hildenbrand	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
7191024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
72cebc774fSAnshuman Khandual	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
731e866974SAnshuman Khandual	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
7491dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
75c2280be8SAnshuman Khandual	select ARCH_HAS_CACHE_LINE_SIZE
761156b441SDavidlohr Bueso	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
777c7077a7SThomas Gleixner	select ARCH_HAS_CPU_FINALIZE_INIT
788f23f5dbSJason Gunthorpe	select ARCH_HAS_CPU_PASID		if IOMMU_SVA
792792d84eSKees Cook	select ARCH_HAS_CURRENT_STACK_POINTER
80fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
81399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
8221266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
83de6c85bfSChristoph Hellwig	select ARCH_HAS_DMA_OPS			if GART_IOMMU || XEN
84b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
856471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
8672d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
876974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
88957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
89bece04b5SMarco Elver	select ARCH_HAS_KCOV			if X86_64
90b0b8a15bSSamuel Holland	select ARCH_HAS_KERNEL_FPU_SUPPORT
910c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
9210bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
9349f88c70SPaul E. McKenney	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
940ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
95c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
9617596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
973010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
9871ce1ab5SKinsey Ho	select ARCH_HAS_HW_PTE_YOUNG
99eed9a328SYu Zhao	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
1000aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
101ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
102d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
103d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
104ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
105ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
106ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
10725c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
108918327e9SKees Cook	select ARCH_HAS_UBSAN
1097e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
11063703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
1116471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
112ba386777SVignesh Balasubramanian	select ARCH_HAVE_EXTRA_ELF_NOTES
11304d5ea46SAneesh Kumar K.V	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
1146471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
11577fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1165e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1173599fe12SThomas Gleixner	select ARCH_STACKWALK
1182c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1196471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1205d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
121d283d422SPasha Tatashin	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
1226471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
12314df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
1243c516f89SSami Tolvanen	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
1253c516f89SSami Tolvanen	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
126583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
127583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
128d2d6422fSSebastian Andrzej Siewior	select ARCH_SUPPORTS_RT
1296471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
130a432b7c0SUros Bizjak	select ARCH_USE_CMPXCHG_LOCKREF		if X86_CMPXCHG64
131dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1326471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1336471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1342ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
135ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
13681c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
137c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
13851c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
13907431506SAnshuman Khandual	select ARCH_WANT_GENERAL_HUGETLB
1403876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
14159612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
1420b6f1582SAneesh Kumar K.V	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
1430b6f1582SAneesh Kumar K.V	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
14438d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
145b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
14610916706SShile Zhang	select BUILDTIME_TABLE_SORT
1476471b825SIngo Molnar	select CLKEVT_I8253
1486471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1496471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1507cf8f44aSAlexander Potapenko	# Word-size accesses may read uninitialized data past the trailing \0
1517cf8f44aSAlexander Potapenko	# in strings and cause false KMSAN reports.
1527cf8f44aSAlexander Potapenko	select DCACHE_WORD_ACCESS		if !KMSAN
1533aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
15445471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
15545471cd9SLinus Torvalds	select EDAC_SUPPORT
1566471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
157cb81deefSThomas Gleixner	select GENERIC_CLOCKEVENTS_BROADCAST_IDLE	if GENERIC_CLOCKEVENTS_BROADCAST
1586471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1596471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1606471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
1615b95f94cSJames Morse	select GENERIC_CPU_DEVICES
16261dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1636471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
16427d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1656471b825SIngo Molnar	select GENERIC_IOMAP
166c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1670fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
168ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1696471b825SIngo Molnar	select GENERIC_IRQ_PROBE
170c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1716471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1726471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1732ae27137SSteven Price	select GENERIC_PTDUMP
1746471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1756471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1767ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
177550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
1787e90ffb7SAdrian Hunter	select GENERIC_VDSO_OVERFLOW_PROTECT
1796ca297d4SPeter Zijlstra	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
18017e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1817edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
182fcbfe812SNiklas Schnelle	select HAS_IOPORT
1836471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1846471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1852a19be61SVlastimil Babka	select HAVE_ALIGNED_STRUCT_PAGE
1866471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1876471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
188eed1fceeSSong Liu	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
1896471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
190b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
191d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1920609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1931dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1944ca8cc8dSAlexander Potapenko	select HAVE_ARCH_KMSAN			if X86_64
1956471b825SIngo Molnar	select HAVE_ARCH_KGDB
1969e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1979e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1981b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
199271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
2006471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
201f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
202afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
2036471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
2046471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
205a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
206b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
2077677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
208e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
209fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
210c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
2112ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
2126471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
2136471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
21424a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER		if X86_64
21524a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
2166471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
21703f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
218280981d6SSathvika Vasireddy	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
2194ed308c4SSteven Rostedt (Google)	select HAVE_BUILDTIME_MCOUNT_SORT
2206471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
2219c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
222677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
22306aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
22402a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
225562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
226c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
227503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
22803f5781bSWang YanQing	select HAVE_EBPF_JIT
22958340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
2306630a8e5SChristoph Hellwig	select HAVE_EISA
2315f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
23225176ad0SDavid Hildenbrand	select HAVE_GUP_FAST
233644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2346471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
235d938ba17SDonglin Peng	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
2364a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2376471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2386b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2390067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2406471b825SIngo Molnar	select HAVE_IOREMAP_PROT
241624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2426471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2434ab7674fSJosh Poimboeuf	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
2446471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2456471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2466471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2476471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2486471b825SIngo Molnar	select HAVE_KERNEL_LZO
2496471b825SIngo Molnar	select HAVE_KERNEL_XZ
250fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2516471b825SIngo Molnar	select HAVE_KPROBES
2526471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
253540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2546471b825SIngo Molnar	select HAVE_KRETPROBES
255f3a112c0SMasami Hiramatsu	select HAVE_RETHOOK
2566471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2570102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
258ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2599f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
260be37c98dSKalesh Singh	select HAVE_MOVE_PUD
26122102f45SJosh Poimboeuf	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
26242a0bb3fSPetr Mladek	select HAVE_NMI
263489e355bSJosh Poimboeuf	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
26403f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL			if X86_64
2656471b825SIngo Molnar	select HAVE_OPTPROBES
2665394f1e9SArnd Bergmann	select HAVE_PAGE_SIZE_4KB
2676471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2686471b825SIngo Molnar	select HAVE_PERF_EVENTS
269c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
27092e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
271eb01d42aSChristoph Hellwig	select HAVE_PCI
272c5e63197SJiri Olsa	select HAVE_PERF_REGS
273c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
274ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
2751e9fdf21SPeter Zijlstra	select MMU_GATHER_MERGE_VMAS
27600998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2776471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
27803f16cd0SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
2793c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
2807ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
281cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
282d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
28303f16cd0SJosh Poimboeuf	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
284e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
28503f16cd0SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
28699cf983cSMark Rutland	select HAVE_PREEMPT_DYNAMIC_CALL
287d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
28809498135SMiguel Ojeda	select HAVE_RUST			if X86_64
2896471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2905f3da8c0SJosh Poimboeuf	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
2916471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2927c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2937ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
29433385150SJason A. Donenfeld	select VDSO_GETRANDOM			if X86_64
2950c7ffa32SThomas Gleixner	select HOTPLUG_PARALLEL			if SMP && X86_64
29605736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
2970c7ffa32SThomas Gleixner	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
298c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
299c2508ec5SLinus Torvalds	select LOCK_MM_AND_FIND_VMA
3007ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
3017ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
30286596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
30387482708SMike Rapoport (Microsoft)	select NUMA_MEMBLKS			if NUMA
3042eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
305625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
3066471b825SIngo Molnar	select PERF_EVENTS
3073195ef59SPrarit Bhargava	select RTC_LIB
308d6faca40SArnd Bergmann	select RTC_MC146818_LIB
3096471b825SIngo Molnar	select SPARSE_IRQ
3106471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
31115f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
3124aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
3134510bffbSMark Rutland	select TRACE_IRQFLAGS_NMI_SUPPORT
3146471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
3153b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
3160c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
31750468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
318d49a0626SPeter Zijlstra	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
319d49a0626SPeter Zijlstra	select FUNCTION_ALIGNMENT_4B
3209e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
321ceea991aSJiri Olsa	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
3227d8330a5SBalbir Singh
323ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
3243120e25eSJan Beulich	def_bool y
3253120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
326ba7e4d13SIngo Molnar
32751b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
32851b26adaSLinus Torvalds	string
32951b26adaSLinus Torvalds	default "elf32-i386" if X86_32
33051b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
33151b26adaSLinus Torvalds
3328d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
3333c2362e6SHarvey Harrison	def_bool y
3348d5fffb9SSam Ravnborg
3358d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
3363c2362e6SHarvey Harrison	def_bool y
3378d5fffb9SSam Ravnborg
3388d5fffb9SSam Ravnborgconfig MMU
3393c2362e6SHarvey Harrison	def_bool y
3408d5fffb9SSam Ravnborg
3419e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
3429e08f57dSDaniel Cashman	default 28 if 64BIT
3439e08f57dSDaniel Cashman	default 8
3449e08f57dSDaniel Cashman
3459e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3469e08f57dSDaniel Cashman	default 32 if 64BIT
3479e08f57dSDaniel Cashman	default 16
3489e08f57dSDaniel Cashman
3499e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3509e08f57dSDaniel Cashman	default 8
3519e08f57dSDaniel Cashman
3529e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3539e08f57dSDaniel Cashman	default 16
3549e08f57dSDaniel Cashman
3558d5fffb9SSam Ravnborgconfig SBUS
3568d5fffb9SSam Ravnborg	bool
3578d5fffb9SSam Ravnborg
3588d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3593120e25eSJan Beulich	def_bool y
3603120e25eSJan Beulich	depends on ISA_DMA_API
3618d5fffb9SSam Ravnborg
362d911c67eSAlexander Potapenkoconfig GENERIC_CSUM
363d911c67eSAlexander Potapenko	bool
364d911c67eSAlexander Potapenko	default y if KMSAN || KASAN
365d911c67eSAlexander Potapenko
3668d5fffb9SSam Ravnborgconfig GENERIC_BUG
3673c2362e6SHarvey Harrison	def_bool y
3688d5fffb9SSam Ravnborg	depends on BUG
369b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
370b93a531eSJan Beulich
371b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
372b93a531eSJan Beulich	bool
3738d5fffb9SSam Ravnborg
3748d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3753120e25eSJan Beulich	def_bool y
3763120e25eSJan Beulich	depends on ISA_DMA_API
3778d5fffb9SSam Ravnborg
3781032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3791032c0baSSam Ravnborg	def_bool y
3801032c0baSSam Ravnborg
3819a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3829a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3838d5fffb9SSam Ravnborg
384801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
385801e4062SJohannes Berg	def_bool y
386801e4062SJohannes Berg
387f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
388f4cb5700SJohannes Berg	def_bool y
389f4cb5700SJohannes Berg
3908d5fffb9SSam Ravnborgconfig AUDIT_ARCH
391e0fd24a3SJan Beulich	def_bool y if X86_64
3928d5fffb9SSam Ravnborg
393d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
394d6f2d75aSAndrey Ryabinin	hex
395d6f2d75aSAndrey Ryabinin	depends on KASAN
396d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
397d6f2d75aSAndrey Ryabinin
39869575d38SShane Wangconfig HAVE_INTEL_TXT
39969575d38SShane Wang	def_bool y
4006ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
40169575d38SShane Wang
4026b0c3d44SSam Ravnborgconfig X86_64_SMP
4036b0c3d44SSam Ravnborg	def_bool y
4046b0c3d44SSam Ravnborg	depends on X86_64 && SMP
4056b0c3d44SSam Ravnborg
4062b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
4072b144498SSrikar Dronamraju	def_bool y
4082b144498SSrikar Dronamraju
409d20642f0SRob Herringconfig FIX_EARLYCON_MEM
410d20642f0SRob Herring	def_bool y
411d20642f0SRob Herring
41294d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
41394d49eb3SKirill A. Shutemov	bool
41494d49eb3SKirill A. Shutemov
41598233368SKirill A. Shutemovconfig PGTABLE_LEVELS
41698233368SKirill A. Shutemov	int
41777ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
41898233368SKirill A. Shutemov	default 4 if X86_64
41998233368SKirill A. Shutemov	default 3 if X86_PAE
42098233368SKirill A. Shutemov	default 2
42198233368SKirill A. Shutemov
4222a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
4232a61f474SMasahiro Yamada	bool
4241b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
4251b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
4262a61f474SMasahiro Yamada	help
4272a61f474SMasahiro Yamada	  We have to make sure stack protector is unconditionally disabled if
4283fb0fdb3SAndy Lutomirski	  the compiler produces broken code or if it does not let us control
4293fb0fdb3SAndy Lutomirski	  the segment on 32-bit kernels.
4302a61f474SMasahiro Yamada
431506f1d07SSam Ravnborgmenu "Processor type and features"
432506f1d07SSam Ravnborg
433506f1d07SSam Ravnborgconfig SMP
434506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
435a7f7f624SMasahiro Yamada	help
436506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4374a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4384a474157SRobert Graffham	  than one CPU, say Y.
439506f1d07SSam Ravnborg
4404a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
441506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
442506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4434a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
444506f1d07SSam Ravnborg	  will run faster if you say N here.
445506f1d07SSam Ravnborg
446506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
447506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
448506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
449506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
450506f1d07SSam Ravnborg
451506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
452506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
453506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
454506f1d07SSam Ravnborg
455ff61f079SJonathan Corbet	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
4564f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
457506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
458506f1d07SSam Ravnborg
459506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
460506f1d07SSam Ravnborg
46106cd9a7dSYinghai Luconfig X86_X2APIC
46206cd9a7dSYinghai Lu	bool "Support x2apic"
46319e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
464a7f7f624SMasahiro Yamada	help
46506cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
46606cd9a7dSYinghai Lu
46706cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
46806cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
46906cd9a7dSYinghai Lu
470b8d1d163SDaniel Sneddon	  Some Intel systems circa 2022 and later are locked into x2APIC mode
471b8d1d163SDaniel Sneddon	  and can not fall back to the legacy APIC modes if SGX or TDX are
472e3998434SMateusz Jończyk	  enabled in the BIOS. They will boot with very reduced functionality
473e3998434SMateusz Jończyk	  without enabling this option.
474b8d1d163SDaniel Sneddon
47506cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
47606cd9a7dSYinghai Lu
4777fec07fdSJacob Panconfig X86_POSTED_MSI
4787fec07fdSJacob Pan	bool "Enable MSI and MSI-x delivery by posted interrupts"
4797fec07fdSJacob Pan	depends on X86_64 && IRQ_REMAP
4807fec07fdSJacob Pan	help
4817fec07fdSJacob Pan	  This enables MSIs that are under interrupt remapping to be delivered as
4827fec07fdSJacob Pan	  posted interrupts to the host kernel. Interrupt throughput can
4837fec07fdSJacob Pan	  potentially be improved by coalescing CPU notifications during high
4847fec07fdSJacob Pan	  frequency bursts.
4857fec07fdSJacob Pan
4867fec07fdSJacob Pan	  If you don't know what to do here, say N.
4877fec07fdSJacob Pan
4886695c85bSYinghai Luconfig X86_MPPARSE
4894590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4907a527688SJan Beulich	default y
4915ab74722SIngo Molnar	depends on X86_LOCAL_APIC
492a7f7f624SMasahiro Yamada	help
4936695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4946695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4956695c85bSYinghai Lu
496e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
497e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4986fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
49959fe5a77SThomas Gleixner	select KERNFS
500e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
50178e99b4aSFenghua Yu	help
502e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
5036fe07ce3SBabu Moger
5046fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
5056fe07ce3SBabu Moger	  usage by the CPU.
5066fe07ce3SBabu Moger
5076fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
5086fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
5096fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
5106fe07ce3SBabu Moger
5116fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
5126fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
5136fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
51478e99b4aSFenghua Yu
51578e99b4aSFenghua Yu	  Say N if unsure.
51678e99b4aSFenghua Yu
5172cce9591SH. Peter Anvin (Intel)config X86_FRED
5182cce9591SH. Peter Anvin (Intel)	bool "Flexible Return and Event Delivery"
5192cce9591SH. Peter Anvin (Intel)	depends on X86_64
5202cce9591SH. Peter Anvin (Intel)	help
5212cce9591SH. Peter Anvin (Intel)	  When enabled, try to use Flexible Return and Event Delivery
5222cce9591SH. Peter Anvin (Intel)	  instead of the legacy SYSCALL/SYSENTER/IDT architecture for
5232cce9591SH. Peter Anvin (Intel)	  ring transitions and exception/interrupt handling if the
5243c41786cSPaul Menzel	  system supports it.
5252cce9591SH. Peter Anvin (Intel)
526a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
527a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
52871d99ea4SMasahiro Yamada	depends on SMP && X86_32
529a7f7f624SMasahiro Yamada	help
530e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
531a0d0bb4dSRandy Dunlap
532c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
533c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
534c5c606d9SRavikiran G Thirumalai	default y
535a7f7f624SMasahiro Yamada	help
53606ac8346SIngo Molnar	  If you disable this option then the kernel will only support
53706ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
53806ac8346SIngo Molnar	  systems out there.)
53906ac8346SIngo Molnar
5408425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
54171d99ea4SMasahiro Yamada	  for the following non-PC x86 platforms, depending on the value of
54271d99ea4SMasahiro Yamada	  CONFIG_64BIT.
54371d99ea4SMasahiro Yamada
54471d99ea4SMasahiro Yamada	  32-bit platforms (CONFIG_64BIT=n):
545cb7b8023SBen Hutchings		Goldfish (Android emulator)
5468425091fSRavikiran G Thirumalai		AMD Elan
5478425091fSRavikiran G Thirumalai		RDC R-321x SoC
5488425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
54983125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5503f4110a4SThomas Gleixner		Moorestown MID devices
55106ac8346SIngo Molnar
55271d99ea4SMasahiro Yamada	  64-bit platforms (CONFIG_64BIT=y):
55344b111b5SSteffen Persvold		Numascale NumaChip
5548425091fSRavikiran G Thirumalai		ScaleMP vSMP
5558425091fSRavikiran G Thirumalai		SGI Ultraviolet
5568425091fSRavikiran G Thirumalai
5578425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5588425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
55971d99ea4SMasahiro Yamada
560c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
561c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
56244b111b5SSteffen Persvoldconfig X86_NUMACHIP
56344b111b5SSteffen Persvold	bool "Numascale NumaChip"
56444b111b5SSteffen Persvold	depends on X86_64
56544b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
56644b111b5SSteffen Persvold	depends on NUMA
56744b111b5SSteffen Persvold	depends on SMP
56844b111b5SSteffen Persvold	depends on X86_X2APIC
569f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
570a7f7f624SMasahiro Yamada	help
57144b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
57244b111b5SSteffen Persvold	  enable more than ~168 cores.
57344b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
57403b48632SNick Piggin
5756a48565eSIngo Molnarconfig X86_VSMP
576c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5776276a074SBorislav Petkov	select HYPERVISOR_GUEST
5786a48565eSIngo Molnar	select PARAVIRT
5796a48565eSIngo Molnar	depends on X86_64 && PCI
580c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
581ead91d4bSShai Fultheim	depends on SMP
582a7f7f624SMasahiro Yamada	help
5836a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5846a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5856a48565eSIngo Molnar	  if you have one of these machines.
5866a48565eSIngo Molnar
587c5c606d9SRavikiran G Thirumalaiconfig X86_UV
588c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
589c5c606d9SRavikiran G Thirumalai	depends on X86_64
590c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
59154c28d29SJack Steiner	depends on NUMA
5921ecb4ae5SAndrew Morton	depends on EFI
593c2209ea5SIngo Molnar	depends on KEXEC_CORE
5949d6c26e7SSuresh Siddha	depends on X86_X2APIC
5951222e564SIngo Molnar	depends on PCI
596a7f7f624SMasahiro Yamada	help
597c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
598c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
599c5c606d9SRavikiran G Thirumalai
600c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
601c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
602506f1d07SSam Ravnborg
603ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
604ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
605cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
606a7f7f624SMasahiro Yamada	help
607ddd70cf9SJun Nakajima	  Enable support for the Goldfish virtual platform used primarily
608ddd70cf9SJun Nakajima	  for Android development. Unless you are building for the Android
609ddd70cf9SJun Nakajima	  Goldfish emulator say N here.
610ddd70cf9SJun Nakajima
611c751e17bSThomas Gleixnerconfig X86_INTEL_CE
612c751e17bSThomas Gleixner	bool "CE4100 TV platform"
613c751e17bSThomas Gleixner	depends on PCI
614c751e17bSThomas Gleixner	depends on PCI_GODIRECT
6156084a6e2SJiang Liu	depends on X86_IO_APIC
616c751e17bSThomas Gleixner	depends on X86_32
617c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
61837bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
619da6b737bSSebastian Andrzej Siewior	select OF
620da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
621a7f7f624SMasahiro Yamada	help
622c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
623c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
624c751e17bSThomas Gleixner	  boxes and media devices.
625c751e17bSThomas Gleixner
6264cb9b00fSDavid Cohenconfig X86_INTEL_MID
62743605ef1SAlan Cox	bool "Intel MID platform support"
62843605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
629edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6301ea7c673SAlan Cox	depends on PCI
6313fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6321ea7c673SAlan Cox	depends on X86_IO_APIC
6334cb9b00fSDavid Cohen	select I2C
6347c9c3a1eSAlan Cox	select DW_APB_TIMER
63554b34aa0SMika Westerberg	select INTEL_SCU_PCI
636a7f7f624SMasahiro Yamada	help
6374cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6384cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6394cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6401ea7c673SAlan Cox
6414cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6424cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
64343605ef1SAlan Cox
6448bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6458bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6468bbc2a13SBryan O'Donoghue	depends on X86_32
6478bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6488bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6498bbc2a13SBryan O'Donoghue	depends on X86_TSC
6508bbc2a13SBryan O'Donoghue	depends on PCI
6518bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6528bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6538bbc2a13SBryan O'Donoghue	select IOSF_MBI
6548bbc2a13SBryan O'Donoghue	select INTEL_IMR
6559ab6eb51SAndy Shevchenko	select COMMON_CLK
656a7f7f624SMasahiro Yamada	help
6578bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6588bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6598bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6608bbc2a13SBryan O'Donoghue
6613d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6623d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6635962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6643d48aab1SMika Westerberg	select COMMON_CLK
6650f531431SMathias Nyman	select PINCTRL
666eebb3e8dSAndy Shevchenko	select IOSF_MBI
667a7f7f624SMasahiro Yamada	help
6683d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6693d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6700f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6710f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6723d48aab1SMika Westerberg
67392082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
67492082a88SKen Xue	bool "AMD ACPI2Platform devices support"
67592082a88SKen Xue	depends on ACPI
67692082a88SKen Xue	select COMMON_CLK
67792082a88SKen Xue	select PINCTRL
678a7f7f624SMasahiro Yamada	help
67992082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
68092082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
68192082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
68292082a88SKen Xue	  implemented under PINCTRL subsystem.
68392082a88SKen Xue
684ced3ce76SDavid E. Boxconfig IOSF_MBI
685ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
686ced3ce76SDavid E. Box	depends on PCI
687a7f7f624SMasahiro Yamada	help
688ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
689ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
690ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
691ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
692ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
693ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
694ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
695ced3ce76SDavid E. Box	   - BayTrail
696ced3ce76SDavid E. Box	   - Braswell
697ced3ce76SDavid E. Box	   - Quark
698ced3ce76SDavid E. Box
699ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
700ced3ce76SDavid E. Box
701ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
702ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
703ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
704a7f7f624SMasahiro Yamada	help
705ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
706ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
707ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
708ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
709ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
710ed2226bdSDavid E. Box	  device they want to access.
711ed2226bdSDavid E. Box
712ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
713ed2226bdSDavid E. Box
714c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
715c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
716506f1d07SSam Ravnborg	depends on X86_32
717c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
718c5c606d9SRavikiran G Thirumalai	select M486
719c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
720a7f7f624SMasahiro Yamada	help
721c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
722c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
723c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
724c5c606d9SRavikiran G Thirumalai
725e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7269c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7279c398017SIngo Molnar	depends on X86_32 && SMP
728c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
729a7f7f624SMasahiro Yamada	help
730b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
731b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
732b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
733b5660ba7SH. Peter Anvin	  one and will fallback to default.
734d49c4288SYinghai Lu
735c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
736d49c4288SYinghai Lu
737d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7386fc108a0SJan Beulich	def_bool y
739d949f36fSLinus Torvalds	# MCE code calls memory_failure():
740d949f36fSLinus Torvalds	depends on X86_MCE
741d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
742d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
743d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
744d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
745d949f36fSLinus Torvalds
74683125a3aSAlessandro Rubiniconfig STA2X11
74783125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
74883125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
74983125a3aSAlessandro Rubini	select SWIOTLB
75083125a3aSAlessandro Rubini	select MFD_STA2X11
7510145071bSLinus Walleij	select GPIOLIB
752a7f7f624SMasahiro Yamada	help
75383125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
75483125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
75583125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
75683125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
75783125a3aSAlessandro Rubini	  standard PC machines.
75883125a3aSAlessandro Rubini
75982148d1dSShérabconfig X86_32_IRIS
76082148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
76182148d1dSShérab	depends on X86_32
762a7f7f624SMasahiro Yamada	help
76382148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
76482148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
76582148d1dSShérab	  needed to do so, which is what this module does at
76682148d1dSShérab	  kernel shutdown.
76782148d1dSShérab
76882148d1dSShérab	  This is only for Iris machines from EuroBraille.
76982148d1dSShérab
77082148d1dSShérab	  If unused, say N.
77182148d1dSShérab
772ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7733c2362e6SHarvey Harrison	def_bool y
7743c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
775a87d0914SKen Chen	depends on X86
776a7f7f624SMasahiro Yamada	help
777506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
778506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
779506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
780506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
781506f1d07SSam Ravnborg
782506f1d07SSam Ravnborg	  If in doubt, say "Y".
783506f1d07SSam Ravnborg
7846276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7856276a074SBorislav Petkov	bool "Linux guest support"
786a7f7f624SMasahiro Yamada	help
7876276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7886276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7896276a074SBorislav Petkov	  setup.
790506f1d07SSam Ravnborg
7916276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7926276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
793506f1d07SSam Ravnborg
7946276a074SBorislav Petkovif HYPERVISOR_GUEST
795506f1d07SSam Ravnborg
796e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
797e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
798a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
799a7f7f624SMasahiro Yamada	help
800e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
801e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
802e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
803e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
804e61bd94aSEduardo Pereira Habkost
805c00a280aSJuergen Grossconfig PARAVIRT_XXL
806c00a280aSJuergen Gross	bool
807c00a280aSJuergen Gross
8086276a074SBorislav Petkovconfig PARAVIRT_DEBUG
8096276a074SBorislav Petkov	bool "paravirt-ops debugging"
8106276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
811a7f7f624SMasahiro Yamada	help
8126276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
8136276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
8146276a074SBorislav Petkov
815b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
816b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8176ea30386SKees Cook	depends on PARAVIRT && SMP
818a7f7f624SMasahiro Yamada	help
819b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
820b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
821b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
822b4ecc126SJeremy Fitzhardinge
8234c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8244c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
825b4ecc126SJeremy Fitzhardinge
8264c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
827b4ecc126SJeremy Fitzhardinge
828ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
829ecca2502SZhao Yakui	def_bool n
830ecca2502SZhao Yakui
8316276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8326276a074SBorislav Petkov
8336276a074SBorislav Petkovconfig KVM_GUEST
8346276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8356276a074SBorislav Petkov	depends on PARAVIRT
8366276a074SBorislav Petkov	select PARAVIRT_CLOCK
837a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
838b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8396276a074SBorislav Petkov	default y
840a7f7f624SMasahiro Yamada	help
8416276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8426276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8436276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8446276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8456276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8466276a074SBorislav Petkov
847a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
848a1c4423bSMarcelo Tosatti	def_bool n
849a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
850a1c4423bSMarcelo Tosatti	help
851a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
852a1c4423bSMarcelo Tosatti
8537733607fSMaran Wilsonconfig PVH
8547733607fSMaran Wilson	bool "Support for running PVH guests"
855a7f7f624SMasahiro Yamada	help
8567733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8577733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8587733607fSMaran Wilson
8596276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8606276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8616276a074SBorislav Petkov	depends on PARAVIRT
862a7f7f624SMasahiro Yamada	help
8636276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8646276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8656276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8666276a074SBorislav Petkov	  that, there can be a small performance impact.
8676276a074SBorislav Petkov
8686276a074SBorislav Petkov	  If in doubt, say N here.
8696276a074SBorislav Petkov
8707af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8717af192c9SGerd Hoffmann	bool
8727af192c9SGerd Hoffmann
8734a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8744a362601SJan Kiszka	bool "Jailhouse non-root cell support"
875abde587bSArnd Bergmann	depends on X86_64 && PCI
87687e65d05SJan Kiszka	select X86_PM_TIMER
877a7f7f624SMasahiro Yamada	help
8784a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8794a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8804a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8814a362601SJan Kiszka
882ec7972c9SZhao Yakuiconfig ACRN_GUEST
883ec7972c9SZhao Yakui	bool "ACRN Guest support"
884ec7972c9SZhao Yakui	depends on X86_64
885498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
886ec7972c9SZhao Yakui	help
887ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
888ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
889ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
890ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
891ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
892ec7972c9SZhao Yakui
89359bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST
89459bd54a8SKuppuswamy Sathyanarayanan	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
89559bd54a8SKuppuswamy Sathyanarayanan	depends on X86_64 && CPU_SUP_INTEL
89659bd54a8SKuppuswamy Sathyanarayanan	depends on X86_X2APIC
89775d090fdSKirill A. Shutemov	depends on EFI_STUB
89841394e33SKirill A. Shutemov	select ARCH_HAS_CC_PLATFORM
899968b4931SKirill A. Shutemov	select X86_MEM_ENCRYPT
90077a512e3SSean Christopherson	select X86_MCE
90175d090fdSKirill A. Shutemov	select UNACCEPTED_MEMORY
90259bd54a8SKuppuswamy Sathyanarayanan	help
90359bd54a8SKuppuswamy Sathyanarayanan	  Support running as a guest under Intel TDX.  Without this support,
90459bd54a8SKuppuswamy Sathyanarayanan	  the guest kernel can not boot or run under TDX.
90559bd54a8SKuppuswamy Sathyanarayanan	  TDX includes memory encryption and integrity capabilities
90659bd54a8SKuppuswamy Sathyanarayanan	  which protect the confidentiality and integrity of guest
90759bd54a8SKuppuswamy Sathyanarayanan	  memory contents and CPU state. TDX guests are protected from
90859bd54a8SKuppuswamy Sathyanarayanan	  some attacks from the VMM.
90959bd54a8SKuppuswamy Sathyanarayanan
9106276a074SBorislav Petkovendif # HYPERVISOR_GUEST
91197349135SJeremy Fitzhardinge
912506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
913506f1d07SSam Ravnborg
914506f1d07SSam Ravnborgconfig HPET_TIMER
9153c2362e6SHarvey Harrison	def_bool X86_64
916506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
917a7f7f624SMasahiro Yamada	help
918506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
919506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
920506f1d07SSam Ravnborg	  present.
921506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
922506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
923506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
9244e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
9254e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
926506f1d07SSam Ravnborg
927506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
928506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
929506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
930506f1d07SSam Ravnborg
931506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
932506f1d07SSam Ravnborg
933506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9343c2362e6SHarvey Harrison	def_bool y
9353228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
936506f1d07SSam Ravnborg
9376a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
938506f1d07SSam Ravnborg# The code disables itself when not needed.
9397ae9392cSThomas Petazzoniconfig DMI
9407ae9392cSThomas Petazzoni	default y
941cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9426a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
943a7f7f624SMasahiro Yamada	help
9447ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9457ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9467ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9477ae9392cSThomas Petazzoni	  BIOS code.
9487ae9392cSThomas Petazzoni
949506f1d07SSam Ravnborgconfig GART_IOMMU
95038901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
951a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
952506f1d07SSam Ravnborg	select SWIOTLB
95323ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
954a7f7f624SMasahiro Yamada	help
955ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
956ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
957ced3c42cSIngo Molnar
958ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
959ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
960ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
961ced3c42cSIngo Molnar
962ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
963ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
964ced3c42cSIngo Molnar
965ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
966ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
967ced3c42cSIngo Molnar	  32-bit limited device.
968ced3c42cSIngo Molnar
969ced3c42cSIngo Molnar	  If unsure, say Y.
970506f1d07SSam Ravnborg
9718b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT
9728b766b0fSMichal Suchanek	bool
9738b766b0fSMichal Suchanek	help
9748b766b0fSMichal Suchanek	  If true, at least one selected framebuffer driver can take advantage
9758b766b0fSMichal Suchanek	  of VESA video modes set at an early boot stage via the vga= parameter.
9768b766b0fSMichal Suchanek
9771184dc2fSMike Travisconfig MAXSMP
978ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9796ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
98036f5101aSMike Travis	select CPUMASK_OFFSTACK
981a7f7f624SMasahiro Yamada	help
982ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9831184dc2fSMike Travis	  If unsure, say N.
984506f1d07SSam Ravnborg
985aec6487eSIngo Molnar#
986aec6487eSIngo Molnar# The maximum number of CPUs supported:
987aec6487eSIngo Molnar#
988aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
989aec6487eSIngo Molnar# and which can be configured interactively in the
990aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
991aec6487eSIngo Molnar#
992aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
993aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
994aec6487eSIngo Molnar#
995aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
996aec6487eSIngo Molnar#   interactive configuration. )
997aec6487eSIngo Molnar#
998a0d0bb4dSRandy Dunlap
999aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
1000a0d0bb4dSRandy Dunlap	int
1001aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
1002a0d0bb4dSRandy Dunlap	default    1 if !SMP
1003a0d0bb4dSRandy Dunlap	default    2
1004a0d0bb4dSRandy Dunlap
1005aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
1006a0d0bb4dSRandy Dunlap	int
1007a0d0bb4dSRandy Dunlap	depends on X86_32
1008aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
1009aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
1010a0d0bb4dSRandy Dunlap	default    1 if !SMP
1011a0d0bb4dSRandy Dunlap
1012aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
1013a0d0bb4dSRandy Dunlap	int
1014a0d0bb4dSRandy Dunlap	depends on X86_64
10151edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
10161edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
1017a0d0bb4dSRandy Dunlap	default    1 if !SMP
1018aec6487eSIngo Molnar
1019aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1020aec6487eSIngo Molnar	int
1021aec6487eSIngo Molnar	depends on X86_32
1022aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
1023aec6487eSIngo Molnar	default    8 if  SMP
1024aec6487eSIngo Molnar	default    1 if !SMP
1025aec6487eSIngo Molnar
1026aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1027aec6487eSIngo Molnar	int
1028aec6487eSIngo Molnar	depends on X86_64
1029a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1030a0d0bb4dSRandy Dunlap	default   64 if  SMP
1031aec6487eSIngo Molnar	default    1 if !SMP
1032a0d0bb4dSRandy Dunlap
1033506f1d07SSam Ravnborgconfig NR_CPUS
103436f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1035aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1036aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1037a7f7f624SMasahiro Yamada	help
1038506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1039bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1040cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1041506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1042506f1d07SSam Ravnborg
1043aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1044aec6487eSIngo Molnar	  to the kernel image.
1045506f1d07SSam Ravnborg
104666558b73STim Chenconfig SCHED_CLUSTER
104766558b73STim Chen	bool "Cluster scheduler support"
104866558b73STim Chen	depends on SMP
104966558b73STim Chen	default y
105066558b73STim Chen	help
105166558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
105266558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
105366558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
105466558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
105566558b73STim Chen	  busses.
105666558b73STim Chen
1057506f1d07SSam Ravnborgconfig SCHED_SMT
1058dbe73364SThomas Gleixner	def_bool y if SMP
1059506f1d07SSam Ravnborg
1060506f1d07SSam Ravnborgconfig SCHED_MC
10613c2362e6SHarvey Harrison	def_bool y
10623c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1063c8e56d20SBorislav Petkov	depends on SMP
1064a7f7f624SMasahiro Yamada	help
1065506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1066506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1067506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1068506f1d07SSam Ravnborg
1069de966cf4STim Chenconfig SCHED_MC_PRIO
1070de966cf4STim Chen	bool "CPU core priorities scheduler support"
10713598e577SMeng Li	depends on SCHED_MC
10723598e577SMeng Li	select X86_INTEL_PSTATE if CPU_SUP_INTEL
10733598e577SMeng Li	select X86_AMD_PSTATE if CPU_SUP_AMD && ACPI
10740a21fc12SIngo Molnar	select CPU_FREQ
1075de966cf4STim Chen	default y
1076a7f7f624SMasahiro Yamada	help
1077de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1078de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1079de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1080de966cf4STim Chen	  single threaded workloads) than others.
1081de966cf4STim Chen
1082de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1083de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1084de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1085de966cf4STim Chen	  overall system performance can be achieved.
1086de966cf4STim Chen
1087de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1088de966cf4STim Chen
1089de966cf4STim Chen	  If unsure say Y here.
10905e76b2abSTim Chen
109130b8b006SThomas Gleixnerconfig UP_LATE_INIT
109230b8b006SThomas Gleixner	def_bool y
1093ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
109430b8b006SThomas Gleixner
1095506f1d07SSam Ravnborgconfig X86_UP_APIC
109650849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
109750849eefSJan Beulich	default PCI_MSI
109838a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1099a7f7f624SMasahiro Yamada	help
1100506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1101506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1102506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1103506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1104506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1105506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1106506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1107506f1d07SSam Ravnborg	  lockups.
1108506f1d07SSam Ravnborg
1109506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1110506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1111506f1d07SSam Ravnborg	depends on X86_UP_APIC
1112a7f7f624SMasahiro Yamada	help
1113506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1114506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1115506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1116506f1d07SSam Ravnborg
1117506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1118506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1119506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1120506f1d07SSam Ravnborg
1121506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
11223c2362e6SHarvey Harrison	def_bool y
11230dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1124b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
1125506f1d07SSam Ravnborg
11262b5e22afSKirill A. Shutemovconfig ACPI_MADT_WAKEUP
11272b5e22afSKirill A. Shutemov	def_bool y
11282b5e22afSKirill A. Shutemov	depends on X86_64
11292b5e22afSKirill A. Shutemov	depends on ACPI
11302b5e22afSKirill A. Shutemov	depends on SMP
11312b5e22afSKirill A. Shutemov	depends on X86_LOCAL_APIC
11322b5e22afSKirill A. Shutemov
1133506f1d07SSam Ravnborgconfig X86_IO_APIC
1134b1da1e71SJan Beulich	def_bool y
1135b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1136506f1d07SSam Ravnborg
113741b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
113841b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
113941b9eb26SStefan Assmann	depends on X86_IO_APIC
1140a7f7f624SMasahiro Yamada	help
114141b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
114241b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
114341b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
114441b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
114541b9eb26SStefan Assmann
114641b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
114741b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
114841b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
114941b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
115041b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
115141b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
115241b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
115341b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
115441b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
115541b9eb26SStefan Assmann	  down (vital) interrupt lines.
115641b9eb26SStefan Assmann
115741b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
115841b9eb26SStefan Assmann	  increased on these systems.
115941b9eb26SStefan Assmann
1160506f1d07SSam Ravnborgconfig X86_MCE
1161bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1162648ed940SChen, Gong	select GENERIC_ALLOCATOR
1163e57dbaf7SBorislav Petkov	default y
1164a7f7f624SMasahiro Yamada	help
1165bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1166bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1167506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1168bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11694efc0670SAndi Kleen
11705de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11715de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11725de97c9fSTony Luck	depends on X86_MCE
1173a7f7f624SMasahiro Yamada	help
11745de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11755de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11765de97c9fSTony Luck	  rasdaemon solution.
11775de97c9fSTony Luck
1178506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11793c2362e6SHarvey Harrison	def_bool y
11803c2362e6SHarvey Harrison	prompt "Intel MCE features"
1181c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1182a7f7f624SMasahiro Yamada	help
1183506f1d07SSam Ravnborg	  Additional support for intel specific MCE features such as
1184506f1d07SSam Ravnborg	  the thermal monitor.
1185506f1d07SSam Ravnborg
1186506f1d07SSam Ravnborgconfig X86_MCE_AMD
11873c2362e6SHarvey Harrison	def_bool y
11883c2362e6SHarvey Harrison	prompt "AMD MCE features"
1189f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1190a7f7f624SMasahiro Yamada	help
1191506f1d07SSam Ravnborg	  Additional support for AMD specific MCE features such as
1192506f1d07SSam Ravnborg	  the DRAM Error Threshold.
1193506f1d07SSam Ravnborg
11944efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11956fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1196c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1197a7f7f624SMasahiro Yamada	help
11984efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11995065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
12004efc0670SAndi Kleen	  line.
12014efc0670SAndi Kleen
1202b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1203b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
12046fc108a0SJan Beulich	def_bool y
1205b2762686SAndi Kleen
1206ea149b36SAndi Kleenconfig X86_MCE_INJECT
1207bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1208ea149b36SAndi Kleen	tristate "Machine check injector support"
1209a7f7f624SMasahiro Yamada	help
1210ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1211ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1212ea149b36SAndi Kleen	  QA it is safe to say n.
1213ea149b36SAndi Kleen
121407dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1215e633c65aSKan Liang
12165aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
12171e642812SIngo Molnar	bool "Legacy VM86 support"
1218506f1d07SSam Ravnborg	depends on X86_32
1219a7f7f624SMasahiro Yamada	help
12205aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
12215aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
12225aef51c3SAndy Lutomirski
12235aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
12245aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
12255aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
12265aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
12275aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
12281e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
12291e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
12301e642812SIngo Molnar	  mode might be faster than emulation and you might want to
12311e642812SIngo Molnar	  enable this option.
12325aef51c3SAndy Lutomirski
12331e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
12341e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12351e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12361e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12375aef51c3SAndy Lutomirski
12381e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12391e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12405aef51c3SAndy Lutomirski
12411e642812SIngo Molnar	  If unsure, say N here.
12425aef51c3SAndy Lutomirski
12435aef51c3SAndy Lutomirskiconfig VM86
12445aef51c3SAndy Lutomirski	bool
12455aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
124634273f41SH. Peter Anvin
124734273f41SH. Peter Anvinconfig X86_16BIT
124834273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
124934273f41SH. Peter Anvin	default y
1250a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1251a7f7f624SMasahiro Yamada	help
125234273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
125334273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
125434273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
125534273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
125634273f41SH. Peter Anvin
125734273f41SH. Peter Anvinconfig X86_ESPFIX32
125834273f41SH. Peter Anvin	def_bool y
125934273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1260506f1d07SSam Ravnborg
1261197725deSH. Peter Anvinconfig X86_ESPFIX64
1262197725deSH. Peter Anvin	def_bool y
126334273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1264506f1d07SSam Ravnborg
12651ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12661ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12671ad83c85SAndy Lutomirski	default y
12681ad83c85SAndy Lutomirski	depends on X86_64
1269a7f7f624SMasahiro Yamada	help
12701ad83c85SAndy Lutomirski	  This enables emulation of the legacy vsyscall page.  Disabling
12711ad83c85SAndy Lutomirski	  it is roughly equivalent to booting with vsyscall=none, except
12721ad83c85SAndy Lutomirski	  that it will also disable the helpful warning if a program
12731ad83c85SAndy Lutomirski	  tries to use a vsyscall.  With this option set to N, offending
12741ad83c85SAndy Lutomirski	  programs will just segfault, citing addresses of the form
12751ad83c85SAndy Lutomirski	  0xffffffffff600?00.
12761ad83c85SAndy Lutomirski
12771ad83c85SAndy Lutomirski	  This option is required by many programs built before 2013, and
12781ad83c85SAndy Lutomirski	  care should be used even with newer programs if set to N.
12791ad83c85SAndy Lutomirski
12801ad83c85SAndy Lutomirski	  Disabling this option saves about 7K of kernel size and
12811ad83c85SAndy Lutomirski	  possibly 4K of additional runtime pagetable memory.
12821ad83c85SAndy Lutomirski
1283111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1284111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1285a24ca997SThomas Gleixner	default y
1286a7f7f624SMasahiro Yamada	help
1287111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1288111e7b15SThomas Gleixner	  for legacy applications.
1289111e7b15SThomas Gleixner
1290c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1291c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1292c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1293c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1294c8137aceSThomas Gleixner	  modules.
1295c8137aceSThomas Gleixner
1296c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1297c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1298a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1299a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1300c8137aceSThomas Gleixner
1301506f1d07SSam Ravnborgconfig TOSHIBA
1302506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1303506f1d07SSam Ravnborg	depends on X86_32
1304a7f7f624SMasahiro Yamada	help
1305506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1306506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1307506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1308506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1309506f1d07SSam Ravnborg
1310506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1311506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1312506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1313506f1d07SSam Ravnborg
1314506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1315506f1d07SSam Ravnborg	  Say N otherwise.
1316506f1d07SSam Ravnborg
1317506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
13189ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
13199ba16087SJan Beulich	depends on X86_32
1320a7f7f624SMasahiro Yamada	help
1321506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1322506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1323506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1324506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1325506f1d07SSam Ravnborg	  system.
1326506f1d07SSam Ravnborg
1327506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
13285e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1329506f1d07SSam Ravnborg
1330506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1331506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1332506f1d07SSam Ravnborg	  Say N otherwise.
1333506f1d07SSam Ravnborg
1334506f1d07SSam Ravnborgconfig MICROCODE
1335e6bcfdd7SThomas Gleixner	def_bool y
133680030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
133780cc9f10SPeter Oruba
1338fdbd4381SThomas Gleixnerconfig MICROCODE_INITRD32
1339fdbd4381SThomas Gleixner	def_bool y
1340fdbd4381SThomas Gleixner	depends on MICROCODE && X86_32 && BLK_DEV_INITRD
1341fdbd4381SThomas Gleixner
1342a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING
1343a77a94f8SBorislav Petkov	bool "Late microcode loading (DANGEROUS)"
1344c02f48e0SBorislav Petkov	default n
1345634ac23aSThomas Gleixner	depends on MICROCODE && SMP
1346a7f7f624SMasahiro Yamada	help
1347a77a94f8SBorislav Petkov	  Loading microcode late, when the system is up and executing instructions
1348a77a94f8SBorislav Petkov	  is a tricky business and should be avoided if possible. Just the sequence
1349a77a94f8SBorislav Petkov	  of synchronizing all cores and SMT threads is one fragile dance which does
1350a77a94f8SBorislav Petkov	  not guarantee that cores might not softlock after the loading. Therefore,
13519407bda8SThomas Gleixner	  use this at your own risk. Late loading taints the kernel unless the
13529407bda8SThomas Gleixner	  microcode header indicates that it is safe for late loading via the
13539407bda8SThomas Gleixner	  minimal revision check. This minimal revision check can be enforced on
13549407bda8SThomas Gleixner	  the kernel command line with "microcode.minrev=Y".
13559407bda8SThomas Gleixner
13569407bda8SThomas Gleixnerconfig MICROCODE_LATE_FORCE_MINREV
13579407bda8SThomas Gleixner	bool "Enforce late microcode loading minimal revision check"
13589407bda8SThomas Gleixner	default n
13599407bda8SThomas Gleixner	depends on MICROCODE_LATE_LOADING
13609407bda8SThomas Gleixner	help
13619407bda8SThomas Gleixner	  To prevent that users load microcode late which modifies already
13629407bda8SThomas Gleixner	  in use features, newer microcode patches have a minimum revision field
13639407bda8SThomas Gleixner	  in the microcode header, which tells the kernel which minimum
13649407bda8SThomas Gleixner	  revision must be active in the CPU to safely load that new microcode
13659407bda8SThomas Gleixner	  late into the running system. If disabled the check will not
13669407bda8SThomas Gleixner	  be enforced but the kernel will be tainted when the minimal
13679407bda8SThomas Gleixner	  revision check fails.
13689407bda8SThomas Gleixner
13699407bda8SThomas Gleixner	  This minimal revision check can also be controlled via the
13709407bda8SThomas Gleixner	  "microcode.minrev" parameter on the kernel command line.
13719407bda8SThomas Gleixner
13729407bda8SThomas Gleixner	  If unsure say Y.
1373506f1d07SSam Ravnborg
1374506f1d07SSam Ravnborgconfig X86_MSR
1375506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1376a7f7f624SMasahiro Yamada	help
1377506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1378506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1379506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1380506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1381506f1d07SSam Ravnborg	  systems.
1382506f1d07SSam Ravnborg
1383506f1d07SSam Ravnborgconfig X86_CPUID
1384506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1385a7f7f624SMasahiro Yamada	help
1386506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1387506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1388506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1389506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1390506f1d07SSam Ravnborg
1391506f1d07SSam Ravnborgchoice
1392506f1d07SSam Ravnborg	prompt "High Memory Support"
13936fc108a0SJan Beulich	default HIGHMEM4G
1394506f1d07SSam Ravnborg	depends on X86_32
1395506f1d07SSam Ravnborg
1396506f1d07SSam Ravnborgconfig NOHIGHMEM
1397506f1d07SSam Ravnborg	bool "off"
1398a7f7f624SMasahiro Yamada	help
1399506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1400506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1401506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1402506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1403506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1404506f1d07SSam Ravnborg	  "high memory".
1405506f1d07SSam Ravnborg
1406506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1407506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1408506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1409506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1410506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1411506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1412506f1d07SSam Ravnborg	  possible.
1413506f1d07SSam Ravnborg
1414506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1415506f1d07SSam Ravnborg	  answer "4GB" here.
1416506f1d07SSam Ravnborg
1417506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1418506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1419506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1420506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1421506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1422506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1423506f1d07SSam Ravnborg
1424506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1425506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1426506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1427506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1428506f1d07SSam Ravnborg	  kernel at boot time.)
1429506f1d07SSam Ravnborg
1430506f1d07SSam Ravnborg	  If unsure, say "off".
1431506f1d07SSam Ravnborg
1432506f1d07SSam Ravnborgconfig HIGHMEM4G
1433506f1d07SSam Ravnborg	bool "4GB"
1434a7f7f624SMasahiro Yamada	help
1435506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1436506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1437506f1d07SSam Ravnborg
1438506f1d07SSam Ravnborgconfig HIGHMEM64G
1439506f1d07SSam Ravnborg	bool "64GB"
144088a2b4edSArnd Bergmann	depends on X86_HAVE_PAE
1441506f1d07SSam Ravnborg	select X86_PAE
1442a7f7f624SMasahiro Yamada	help
1443506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1444506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1445506f1d07SSam Ravnborg
1446506f1d07SSam Ravnborgendchoice
1447506f1d07SSam Ravnborg
1448506f1d07SSam Ravnborgchoice
14496a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1450506f1d07SSam Ravnborg	default VMSPLIT_3G
1451506f1d07SSam Ravnborg	depends on X86_32
1452a7f7f624SMasahiro Yamada	help
1453506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1454506f1d07SSam Ravnborg
1455506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1456506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1457506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1458506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1459506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1460506f1d07SSam Ravnborg	  available to user programs, making the address space there
1461506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1462506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1463506f1d07SSam Ravnborg	  kernel modules.
1464506f1d07SSam Ravnborg
1465506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1466506f1d07SSam Ravnborg	  option alone!
1467506f1d07SSam Ravnborg
1468506f1d07SSam Ravnborg	config VMSPLIT_3G
1469506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1470506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1471506f1d07SSam Ravnborg		depends on !X86_PAE
1472506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1473506f1d07SSam Ravnborg	config VMSPLIT_2G
1474506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1475506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1476506f1d07SSam Ravnborg		depends on !X86_PAE
1477506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1478506f1d07SSam Ravnborg	config VMSPLIT_1G
1479506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1480506f1d07SSam Ravnborgendchoice
1481506f1d07SSam Ravnborg
1482506f1d07SSam Ravnborgconfig PAGE_OFFSET
1483506f1d07SSam Ravnborg	hex
1484506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1485506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1486506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1487506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1488506f1d07SSam Ravnborg	default 0xC0000000
1489506f1d07SSam Ravnborg	depends on X86_32
1490506f1d07SSam Ravnborg
1491506f1d07SSam Ravnborgconfig HIGHMEM
14923c2362e6SHarvey Harrison	def_bool y
1493506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1494506f1d07SSam Ravnborg
1495506f1d07SSam Ravnborgconfig X86_PAE
14969ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
149788a2b4edSArnd Bergmann	depends on X86_32 && X86_HAVE_PAE
1498d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14999d99c712SChristian Melki	select SWIOTLB
1500a7f7f624SMasahiro Yamada	help
1501506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1502506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1503506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1504506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1505506f1d07SSam Ravnborg
150677ef56e4SKirill A. Shutemovconfig X86_5LEVEL
150777ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
150818ec1eafSKirill A. Shutemov	default y
1509eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1510162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
151177ef56e4SKirill A. Shutemov	depends on X86_64
1512a7f7f624SMasahiro Yamada	help
151377ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
151477ef56e4SKirill A. Shutemov	  up to 128 PiB of virtual address space and 4 PiB of
151577ef56e4SKirill A. Shutemov	  physical address space.
151677ef56e4SKirill A. Shutemov
151777ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
151877ef56e4SKirill A. Shutemov
15196657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15206657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
152177ef56e4SKirill A. Shutemov
1522ff61f079SJonathan Corbet	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
152377ef56e4SKirill A. Shutemov	  information.
152477ef56e4SKirill A. Shutemov
152577ef56e4SKirill A. Shutemov	  Say N if unsure.
152677ef56e4SKirill A. Shutemov
152710971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1528e5008abeSLuis R. Rodriguez	def_bool y
15292e1da13fSVlastimil Babka	depends on X86_64
1530a7f7f624SMasahiro Yamada	help
153110971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
153210971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
153310971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
153410971ab2SIngo Molnar	  that we have them enabled.
15359e899816SNick Piggin
15365c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15375c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15385c280cf6SThomas Gleixner	depends on DEBUG_FS
1539a7f7f624SMasahiro Yamada	help
1540b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1541a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15425c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15435c280cf6SThomas Gleixner
154420f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT
154520f07a04SKirill A. Shutemov	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
154620f07a04SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
154720f07a04SKirill A. Shutemov	def_bool n
154820f07a04SKirill A. Shutemov
15497744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15507744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15517744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
15526c321179STom Lendacky	depends on EFI_STUB
155382fef0adSDavid Rientjes	select DMA_COHERENT_POOL
1554ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1555597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1556aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
155720f07a04SKirill A. Shutemov	select X86_MEM_ENCRYPT
15586c321179STom Lendacky	select UNACCEPTED_MEMORY
1559a7f7f624SMasahiro Yamada	help
15607744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15617744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15627744ccdbSTom Lendacky	  Encryption (SME).
15637744ccdbSTom Lendacky
1564506f1d07SSam Ravnborg# Common NUMA Features
1565506f1d07SSam Ravnborgconfig NUMA
1566e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1567506f1d07SSam Ravnborg	depends on SMP
1568b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1569b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15707ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
15710c436a58SSaurabh Sengar	select OF_NUMA if OF
1572a7f7f624SMasahiro Yamada	help
1573e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1574fd51b2d7SKOSAKI Motohiro
1575506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1576506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1577506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1578506f1d07SSam Ravnborg
1579c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1580fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1581fd51b2d7SKOSAKI Motohiro
1582b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15837cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1584fd51b2d7SKOSAKI Motohiro
1585fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1586506f1d07SSam Ravnborg
1587eec1d4faSHans Rosenfeldconfig AMD_NUMA
15883c2362e6SHarvey Harrison	def_bool y
15893c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15905da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1591a7f7f624SMasahiro Yamada	help
1592eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1593eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1594eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1595eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1596eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1597506f1d07SSam Ravnborg
1598506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15993c2362e6SHarvey Harrison	def_bool y
16003c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1601506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1602506f1d07SSam Ravnborg	select ACPI_NUMA
1603a7f7f624SMasahiro Yamada	help
1604506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1605506f1d07SSam Ravnborg
1606506f1d07SSam Ravnborgconfig NODES_SHIFT
1607d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
160851591e31SDavid Rientjes	range 1 10
160951591e31SDavid Rientjes	default "10" if MAXSMP
1610506f1d07SSam Ravnborg	default "6" if X86_64
1611506f1d07SSam Ravnborg	default "3"
1612a9ee6cf5SMike Rapoport	depends on NUMA
1613a7f7f624SMasahiro Yamada	help
16141184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1615692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1616506f1d07SSam Ravnborg
1617506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1618506f1d07SSam Ravnborg	def_bool y
16193b16651fSTejun Heo	depends on X86_32 && !NUMA
1620506f1d07SSam Ravnborg
1621506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1622506f1d07SSam Ravnborg	def_bool y
16236ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1624506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1625506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1626506f1d07SSam Ravnborg
16273b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16286ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16293b16651fSTejun Heo
1630506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1631506f1d07SSam Ravnborg	def_bool y
16324eda2bc3SDavid Hildenbrand	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1633506f1d07SSam Ravnborg
1634506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1635a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16365c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1637a0842b70SToshi Kani	help
1638a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1639cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1640a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1641506f1d07SSam Ravnborg
16423b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16433b16651fSTejun Heo	def_bool y
16443b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16453b16651fSTejun Heo
1646a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1647a29815a3SAvi Kivity	hex
1648a29815a3SAvi Kivity	default 0 if X86_32
1649a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1650a29815a3SAvi Kivity
16517a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16527a67832cSDan Williams	bool
16537a67832cSDan Williams
1654ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16557a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16569f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16579f53f9faSDan Williams	depends on BLK_DEV
16587a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16597b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16609f53f9faSDan Williams	select LIBNVDIMM
1661ec776ef6SChristoph Hellwig	help
1662ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1663ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1664ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1665ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1666ec776ef6SChristoph Hellwig
1667ec776ef6SChristoph Hellwig	  Say Y if unsure.
1668ec776ef6SChristoph Hellwig
1669506f1d07SSam Ravnborgconfig HIGHPTE
1670506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16716fc108a0SJan Beulich	depends on HIGHMEM
1672a7f7f624SMasahiro Yamada	help
1673506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1674506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1675506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1676506f1d07SSam Ravnborg	  entries in high memory.
1677506f1d07SSam Ravnborg
16789f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16799f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1680a7f7f624SMasahiro Yamada	help
16819f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16829f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16839f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16849f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16859f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16869f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16879f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16888c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16899f077871SJeremy Fitzhardinge
16909f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16919f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16929f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16939f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16949f077871SJeremy Fitzhardinge
16959f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16969f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16979f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16989f077871SJeremy Fitzhardinge	  memory.
16999f077871SJeremy Fitzhardinge
1700c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1701c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1702c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1703c885df50SJeremy Fitzhardinge	default y
1704a7f7f624SMasahiro Yamada	help
1705c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1706c885df50SJeremy Fitzhardinge	  on or off.
1707c885df50SJeremy Fitzhardinge
1708506f1d07SSam Ravnborgconfig MATH_EMULATION
1709506f1d07SSam Ravnborg	bool
1710a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
171187d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1712a7f7f624SMasahiro Yamada	help
1713506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1714506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1715506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1716506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1717506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1718506f1d07SSam Ravnborg	  coprocessor or this emulation.
1719506f1d07SSam Ravnborg
1720506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1721506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1722506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1723506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1724506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1725506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1726506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1727506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1728506f1d07SSam Ravnborg
1729506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1730506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1731506f1d07SSam Ravnborg
1732506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1733506f1d07SSam Ravnborg	  kernel, it won't hurt.
1734506f1d07SSam Ravnborg
1735506f1d07SSam Ravnborgconfig MTRR
17366fc108a0SJan Beulich	def_bool y
17376a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1738a7f7f624SMasahiro Yamada	help
1739506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1740506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1741506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1742506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1743506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1744506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1745506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1746506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1747506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1748506f1d07SSam Ravnborg
1749506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1750506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1751506f1d07SSam Ravnborg	  as well:
1752506f1d07SSam Ravnborg
1753506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1754506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1755506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1756506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1757506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1758506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1759506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1760506f1d07SSam Ravnborg
1761506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1762506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1763506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1764506f1d07SSam Ravnborg
1765506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1766506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1767506f1d07SSam Ravnborg
1768ff61f079SJonathan Corbet	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1769506f1d07SSam Ravnborg
177095ffa243SYinghai Luconfig MTRR_SANITIZER
17712ffb3501SYinghai Lu	def_bool y
177295ffa243SYinghai Lu	prompt "MTRR cleanup support"
177395ffa243SYinghai Lu	depends on MTRR
1774a7f7f624SMasahiro Yamada	help
1775aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1776aba3728cSThomas Gleixner	  add writeback entries.
177795ffa243SYinghai Lu
1778aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1779692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1780aba3728cSThomas Gleixner	  mtrr_chunk_size.
178195ffa243SYinghai Lu
17822ffb3501SYinghai Lu	  If unsure, say Y.
178395ffa243SYinghai Lu
178495ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1785f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1786f5098d62SYinghai Lu	range 0 1
1787f5098d62SYinghai Lu	default "0"
178895ffa243SYinghai Lu	depends on MTRR_SANITIZER
1789a7f7f624SMasahiro Yamada	help
1790f5098d62SYinghai Lu	  Enable mtrr cleanup default value
179195ffa243SYinghai Lu
179212031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
179312031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
179412031a62SYinghai Lu	range 0 7
179512031a62SYinghai Lu	default "1"
179612031a62SYinghai Lu	depends on MTRR_SANITIZER
1797a7f7f624SMasahiro Yamada	help
179812031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1799aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
180012031a62SYinghai Lu
18012e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18026fc108a0SJan Beulich	def_bool y
18036a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18042a8a2719SIngo Molnar	depends on MTRR
18057a87225aSMatthew Wilcox (Oracle)	select ARCH_USES_PG_ARCH_2
1806a7f7f624SMasahiro Yamada	help
18072e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1808042b78e4SVenki Pallipadi
18092e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18102e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18112e5d9c85Svenkatesh.pallipadi@intel.com
18122e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1813042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18142e5d9c85Svenkatesh.pallipadi@intel.com
18152e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18162e5d9c85Svenkatesh.pallipadi@intel.com
1817b971880fSBabu Mogerconfig X86_UMIP
1818796ebc81SRicardo Neri	def_bool y
1819b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1820a7f7f624SMasahiro Yamada	help
1821b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1822b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1823b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1824b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1825b971880fSBabu Moger	  information about the hardware state.
1826796ebc81SRicardo Neri
1827796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1828796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1829796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1830796ebc81SRicardo Neri	  results are dummy.
1831aa35f896SRicardo Neri
1832156ff4a5SPeter Zijlstraconfig CC_HAS_IBT
1833156ff4a5SPeter Zijlstra	# GCC >= 9 and binutils >= 2.29
1834156ff4a5SPeter Zijlstra	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1835156ff4a5SPeter Zijlstra	# Clang/LLVM >= 14
1836262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1837262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1838156ff4a5SPeter Zijlstra	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1839262448f3SNathan Chancellor		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1840156ff4a5SPeter Zijlstra		  $(as-instr,endbr64)
1841156ff4a5SPeter Zijlstra
184218e66b69SRick Edgecombeconfig X86_CET
184318e66b69SRick Edgecombe	def_bool n
184418e66b69SRick Edgecombe	help
184518e66b69SRick Edgecombe	  CET features configured (Shadow stack or IBT)
184618e66b69SRick Edgecombe
1847156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT
1848156ff4a5SPeter Zijlstra	prompt "Indirect Branch Tracking"
18494fd5f70cSKees Cook	def_bool y
185003f16cd0SJosh Poimboeuf	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1851f6a2c2b2SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1852f6a2c2b2SNathan Chancellor	depends on !LD_IS_LLD || LLD_VERSION >= 140000
185303f16cd0SJosh Poimboeuf	select OBJTOOL
185418e66b69SRick Edgecombe	select X86_CET
1855156ff4a5SPeter Zijlstra	help
1856156ff4a5SPeter Zijlstra	  Build the kernel with support for Indirect Branch Tracking, a
1857156ff4a5SPeter Zijlstra	  hardware support course-grain forward-edge Control Flow Integrity
1858156ff4a5SPeter Zijlstra	  protection. It enforces that all indirect calls must land on
1859156ff4a5SPeter Zijlstra	  an ENDBR instruction, as such, the compiler will instrument the
1860156ff4a5SPeter Zijlstra	  code with them to make this happen.
1861156ff4a5SPeter Zijlstra
1862ed53a0d9SPeter Zijlstra	  In addition to building the kernel with IBT, seal all functions that
18634cdfc11bSNur Hussein	  are not indirect call targets, avoiding them ever becoming one.
1864ed53a0d9SPeter Zijlstra
1865ed53a0d9SPeter Zijlstra	  This requires LTO like objtool runs and will slow down the build. It
1866ed53a0d9SPeter Zijlstra	  does significantly reduce the number of ENDBR instructions in the
1867ed53a0d9SPeter Zijlstra	  kernel image.
1868ed53a0d9SPeter Zijlstra
186935e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
187038f3e775SBabu Moger	prompt "Memory Protection Keys"
187135e97790SDave Hansen	def_bool y
1872284244a9SDave Hansen	# Note: only available in 64-bit mode
187338f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
187452c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
187552c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1876a7f7f624SMasahiro Yamada	help
1877284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1878284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1879284244a9SDave Hansen	  page tables when an application changes protection domains.
1880284244a9SDave Hansen
18811eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1882284244a9SDave Hansen
1883284244a9SDave Hansen	  If unsure, say y.
188435e97790SDave Hansen
18855626f8d4SJoey Goulyconfig ARCH_PKEY_BITS
18865626f8d4SJoey Gouly	int
18875626f8d4SJoey Gouly	default 4
18885626f8d4SJoey Gouly
1889db616173SMichal Hockochoice
1890db616173SMichal Hocko	prompt "TSX enable mode"
1891db616173SMichal Hocko	depends on CPU_SUP_INTEL
1892db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1893db616173SMichal Hocko	help
1894db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1895db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1896db616173SMichal Hocko	  can lead to a noticeable performance boost.
1897db616173SMichal Hocko
1898db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1899db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1900db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1901db616173SMichal Hocko
1902db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1903db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1904db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1905db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1906db616173SMichal Hocko	  for the particular machine.
1907db616173SMichal Hocko
1908db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1909db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1910db616173SMichal Hocko	  details.
1911db616173SMichal Hocko
1912db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1913db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1914db616173SMichal Hocko	  relevant.
1915db616173SMichal Hocko
1916db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1917db616173SMichal Hocko	bool "off"
1918db616173SMichal Hocko	help
1919db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1920db616173SMichal Hocko
1921db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1922db616173SMichal Hocko	bool "on"
1923db616173SMichal Hocko	help
1924db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1925db616173SMichal Hocko	  line parameter.
1926db616173SMichal Hocko
1927db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1928db616173SMichal Hocko	bool "auto"
1929db616173SMichal Hocko	help
1930db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1931db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1932db616173SMichal Hockoendchoice
1933db616173SMichal Hocko
1934e7e05452SSean Christophersonconfig X86_SGX
1935e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1936b8d1d163SDaniel Sneddon	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1937e7e05452SSean Christopherson	depends on CRYPTO=y
1938e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1939e7e05452SSean Christopherson	select MMU_NOTIFIER
1940901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
194140e0e784STony Luck	select XARRAY_MULTI
1942e7e05452SSean Christopherson	help
1943e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1944e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1945e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1946e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1947e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1948e7e05452SSean Christopherson	  hardware.
1949e7e05452SSean Christopherson
1950e7e05452SSean Christopherson	  If unsure, say N.
1951e7e05452SSean Christopherson
195218e66b69SRick Edgecombeconfig X86_USER_SHADOW_STACK
195318e66b69SRick Edgecombe	bool "X86 userspace shadow stack"
195418e66b69SRick Edgecombe	depends on AS_WRUSS
195518e66b69SRick Edgecombe	depends on X86_64
195618e66b69SRick Edgecombe	select ARCH_USES_HIGH_VMA_FLAGS
195718e66b69SRick Edgecombe	select X86_CET
195818e66b69SRick Edgecombe	help
195918e66b69SRick Edgecombe	  Shadow stack protection is a hardware feature that detects function
196018e66b69SRick Edgecombe	  return address corruption.  This helps mitigate ROP attacks.
196118e66b69SRick Edgecombe	  Applications must be enabled to use it, and old userspace does not
196218e66b69SRick Edgecombe	  get protection "for free".
196318e66b69SRick Edgecombe
196418e66b69SRick Edgecombe	  CPUs supporting shadow stacks were first released in 2020.
196518e66b69SRick Edgecombe
196654acee60SDave Hansen	  See Documentation/arch/x86/shstk.rst for more information.
196718e66b69SRick Edgecombe
196818e66b69SRick Edgecombe	  If unsure, say N.
196918e66b69SRick Edgecombe
1970c33621b4SKai Huangconfig INTEL_TDX_HOST
1971c33621b4SKai Huang	bool "Intel Trust Domain Extensions (TDX) host support"
1972c33621b4SKai Huang	depends on CPU_SUP_INTEL
1973c33621b4SKai Huang	depends on X86_64
1974c33621b4SKai Huang	depends on KVM_INTEL
19753115cabdSKai Huang	depends on X86_X2APIC
1976abe8dbabSKai Huang	select ARCH_KEEP_MEMBLOCK
1977ac3a2208SKai Huang	depends on CONTIG_ALLOC
1978cb8eb06dSDave Hansen	depends on !KEXEC_CORE
197983e1bdc9SKai Huang	depends on X86_MCE
1980c33621b4SKai Huang	help
1981c33621b4SKai Huang	  Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
1982c33621b4SKai Huang	  host and certain physical attacks.  This option enables necessary TDX
1983c33621b4SKai Huang	  support in the host kernel to run confidential VMs.
1984c33621b4SKai Huang
1985c33621b4SKai Huang	  If unsure, say N.
1986c33621b4SKai Huang
1987506f1d07SSam Ravnborgconfig EFI
19889ba16087SJan Beulich	bool "EFI runtime service support"
19895b83683fSHuang, Ying	depends on ACPI
1990f6ce5002SSergey Vlasov	select UCS2_STRING
1991022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19921ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
1993aba7e066SArd Biesheuvel	select EFI_RUNTIME_MAP if KEXEC_CORE
1994a7f7f624SMasahiro Yamada	help
19958b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1996506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1997506f1d07SSam Ravnborg
19988b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19998b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
20008b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
20018b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
20028b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
20038b2cb7a8SHuang, Ying	  platforms.
2004506f1d07SSam Ravnborg
2005291f3632SMatt Flemingconfig EFI_STUB
2006291f3632SMatt Fleming	bool "EFI stub support"
2007c6dbd3e5SPeter Zijlstra	depends on EFI
20087b2a583aSMatt Fleming	select RELOCATABLE
2009a7f7f624SMasahiro Yamada	help
2010291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
2011291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
2012291f3632SMatt Fleming
20134f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
20140c759662SMatt Fleming
2015cc3fdda2SArd Biesheuvelconfig EFI_HANDOVER_PROTOCOL
2016cc3fdda2SArd Biesheuvel	bool "EFI handover protocol (DEPRECATED)"
2017cc3fdda2SArd Biesheuvel	depends on EFI_STUB
2018cc3fdda2SArd Biesheuvel	default y
2019cc3fdda2SArd Biesheuvel	help
2020cc3fdda2SArd Biesheuvel	  Select this in order to include support for the deprecated EFI
2021cc3fdda2SArd Biesheuvel	  handover protocol, which defines alternative entry points into the
2022cc3fdda2SArd Biesheuvel	  EFI stub.  This is a practice that has no basis in the UEFI
2023cc3fdda2SArd Biesheuvel	  specification, and requires a priori knowledge on the part of the
2024cc3fdda2SArd Biesheuvel	  bootloader about Linux/x86 specific ways of passing the command line
2025cc3fdda2SArd Biesheuvel	  and initrd, and where in memory those assets may be loaded.
2026cc3fdda2SArd Biesheuvel
2027cc3fdda2SArd Biesheuvel	  If in doubt, say Y. Even though the corresponding support is not
2028cc3fdda2SArd Biesheuvel	  present in upstream GRUB or other bootloaders, most distros build
2029cc3fdda2SArd Biesheuvel	  GRUB with numerous downstream patches applied, and may rely on the
2030cc3fdda2SArd Biesheuvel	  handover protocol as as result.
2031cc3fdda2SArd Biesheuvel
20327d453eeeSMatt Flemingconfig EFI_MIXED
20337d453eeeSMatt Fleming	bool "EFI mixed-mode support"
20347d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
2035a7f7f624SMasahiro Yamada	help
20367d453eeeSMatt Fleming	  Enabling this feature allows a 64-bit kernel to be booted
20377d453eeeSMatt Fleming	  on a 32-bit firmware, provided that your CPU supports 64-bit
20387d453eeeSMatt Fleming	  mode.
20397d453eeeSMatt Fleming
20407d453eeeSMatt Fleming	  Note that it is not possible to boot a mixed-mode enabled
20417d453eeeSMatt Fleming	  kernel via the EFI boot stub - a bootloader that supports
20427d453eeeSMatt Fleming	  the EFI handover protocol must be used.
20437d453eeeSMatt Fleming
20447d453eeeSMatt Fleming	  If unsure, say N.
20457d453eeeSMatt Fleming
20461fff234dSArd Biesheuvelconfig EFI_RUNTIME_MAP
20471fff234dSArd Biesheuvel	bool "Export EFI runtime maps to sysfs" if EXPERT
20481fff234dSArd Biesheuvel	depends on EFI
20491fff234dSArd Biesheuvel	help
20501fff234dSArd Biesheuvel	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
20511fff234dSArd Biesheuvel	  That memory map is required by the 2nd kernel to set up EFI virtual
20521fff234dSArd Biesheuvel	  mappings after kexec, but can also be used for debugging purposes.
20531fff234dSArd Biesheuvel
20541fff234dSArd Biesheuvel	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
20551fff234dSArd Biesheuvel
20568636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
2057506f1d07SSam Ravnborg
20586af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC
20596af51380SEric DeVolder	def_bool y
2060506f1d07SSam Ravnborg
20616af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_FILE
2062c1ad12eeSArnd Bergmann	def_bool X86_64
2063506f1d07SSam Ravnborg
20646af51380SEric DeVolderconfig ARCH_SELECTS_KEXEC_FILE
20656af51380SEric DeVolder	def_bool y
20666af51380SEric DeVolder	depends on KEXEC_FILE
2067b69a2afdSJonathan McDowell	select HAVE_IMA_KEXEC if IMA
206874ca317cSVivek Goyal
2069e6265fe7SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_PURGATORY
2070c1ad12eeSArnd Bergmann	def_bool y
2071b799a09fSAKASHI Takahiro
20726af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_SIG
20736af51380SEric DeVolder	def_bool y
207499d5cadfSJiri Bohac
20756af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_SIG_FORCE
20766af51380SEric DeVolder	def_bool y
207799d5cadfSJiri Bohac
20786af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
20796af51380SEric DeVolder	def_bool y
208099d5cadfSJiri Bohac
20816af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_JUMP
20826af51380SEric DeVolder	def_bool y
20838e7d8381SVivek Goyal
20846af51380SEric DeVolderconfig ARCH_SUPPORTS_CRASH_DUMP
20856af51380SEric DeVolder	def_bool X86_64 || (X86_32 && HIGHMEM)
20868e7d8381SVivek Goyal
2087*31daa343SDave Vasilevskyconfig ARCH_DEFAULT_CRASH_DUMP
2088*31daa343SDave Vasilevsky	def_bool y
2089*31daa343SDave Vasilevsky
2090ea53ad9cSEric DeVolderconfig ARCH_SUPPORTS_CRASH_HOTPLUG
2091ea53ad9cSEric DeVolder	def_bool y
20923ab83521SHuang Ying
20939c08a2a1SBaoquan Heconfig ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
209485fcde40SBaoquan He	def_bool CRASH_RESERVE
20959c08a2a1SBaoquan He
2096506f1d07SSam Ravnborgconfig PHYSICAL_START
20976a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2098ceefccc9SH. Peter Anvin	default "0x1000000"
2099a7f7f624SMasahiro Yamada	help
2100506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2101506f1d07SSam Ravnborg
210243b1d3e6SChris Koch	  If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage
210343b1d3e6SChris Koch	  will decompress itself to above physical address and run from there.
210443b1d3e6SChris Koch	  Otherwise, bzImage will run from the address where it has been loaded
210543b1d3e6SChris Koch	  by the boot loader. The only exception is if it is loaded below the
210643b1d3e6SChris Koch	  above physical address, in which case it will relocate itself there.
2107506f1d07SSam Ravnborg
2108506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2109506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2110506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2111506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2112506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2113506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2114506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2115506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2116506f1d07SSam Ravnborg
2117ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2118ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2119ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2120ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2121ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2122ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2123ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2124330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2125ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2126506f1d07SSam Ravnborg
2127506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2128506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2129506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2130506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2131506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2132506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2133506f1d07SSam Ravnborg	  line.
2134506f1d07SSam Ravnborg
2135506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2136506f1d07SSam Ravnborg
2137506f1d07SSam Ravnborgconfig RELOCATABLE
213826717808SH. Peter Anvin	bool "Build a relocatable kernel"
213926717808SH. Peter Anvin	default y
2140a7f7f624SMasahiro Yamada	help
2141506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2142506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2143506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2144506f1d07SSam Ravnborg	  but are discarded at runtime.
2145506f1d07SSam Ravnborg
2146506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2147506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2148506f1d07SSam Ravnborg	  kernel.
2149506f1d07SSam Ravnborg
2150506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2151506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21528ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2153506f1d07SSam Ravnborg
21548ab3820fSKees Cookconfig RANDOMIZE_BASE
2155e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21568ab3820fSKees Cook	depends on RELOCATABLE
21576807c846SIngo Molnar	default y
2158a7f7f624SMasahiro Yamada	help
2159e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2160e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2161e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2162e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2163e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2164e8581e3dSBaoquan He	  code internals.
2165e8581e3dSBaoquan He
2166ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2167ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2168ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2169ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2170ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2171ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2172ed9f007eSKees Cook
2173ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2174ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2175ed9f007eSKees Cook	  512MB (8 bits of entropy).
21768ab3820fSKees Cook
2177a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2178e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2179e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2180ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2181ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2182ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2183ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2184ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2185ed9f007eSKees Cook	  limited due to memory layouts.
2186e8581e3dSBaoquan He
21876807c846SIngo Molnar	  If unsure, say Y.
2188da2b6fb9SKees Cook
21898ab3820fSKees Cook# Relocation on x86 needs some additional build support
2190845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2191845adf72SH. Peter Anvin	def_bool y
21928ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2193845adf72SH. Peter Anvin
2194506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2195a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21968ab3820fSKees Cook	default "0x200000"
2197a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2198a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2199a7f7f624SMasahiro Yamada	help
2200506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2201506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2202506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2203506f1d07SSam Ravnborg
2204506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2205506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2206506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2207506f1d07SSam Ravnborg
2208506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2209506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2210506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2211506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2212506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2213506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2214506f1d07SSam Ravnborg	  above alignment restrictions.
2215506f1d07SSam Ravnborg
2216a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2217a0215061SKees Cook	  this value must be a multiple of 0x200000.
2218a0215061SKees Cook
2219506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2220506f1d07SSam Ravnborg
2221eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2222eedb92abSKirill A. Shutemov	bool
2223a7f7f624SMasahiro Yamada	help
2224eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2225eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2226eedb92abSKirill A. Shutemov
22270483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22280483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22290483e1faSThomas Garnier	depends on X86_64
22300483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2231eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22320483e1faSThomas Garnier	default RANDOMIZE_BASE
2233a7f7f624SMasahiro Yamada	help
22340483e1faSThomas Garnier	  Randomizes the base virtual address of kernel memory sections
22350483e1faSThomas Garnier	  (physical memory mapping, vmalloc & vmemmap). This security feature
22360483e1faSThomas Garnier	  makes exploits relying on predictable memory locations less reliable.
22370483e1faSThomas Garnier
22380483e1faSThomas Garnier	  The order of allocations remains unchanged. Entropy is generated in
22390483e1faSThomas Garnier	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
22400483e1faSThomas Garnier	  configuration have in average 30,000 different possible virtual
22410483e1faSThomas Garnier	  addresses for each memory section.
22420483e1faSThomas Garnier
22436807c846SIngo Molnar	  If unsure, say Y.
22440483e1faSThomas Garnier
224590397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
224690397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
224790397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
224890397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
224990397a41SThomas Garnier	default "0x0"
225090397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
225190397a41SThomas Garnier	range 0x0 0x40
2252a7f7f624SMasahiro Yamada	help
225390397a41SThomas Garnier	  Define the padding in terabytes added to the existing physical
225490397a41SThomas Garnier	  memory size during kernel memory randomization. It is useful
225590397a41SThomas Garnier	  for memory hotplug support but reduces the entropy available for
225690397a41SThomas Garnier	  address randomization.
225790397a41SThomas Garnier
225890397a41SThomas Garnier	  If unsure, leave at the default value.
225990397a41SThomas Garnier
22606449dcb0SKirill A. Shutemovconfig ADDRESS_MASKING
22616449dcb0SKirill A. Shutemov	bool "Linear Address Masking support"
22626449dcb0SKirill A. Shutemov	depends on X86_64
22633267cb6dSPawan Gupta	depends on COMPILE_TEST || !CPU_MITIGATIONS # wait for LASS
22646449dcb0SKirill A. Shutemov	help
22656449dcb0SKirill A. Shutemov	  Linear Address Masking (LAM) modifies the checking that is applied
22666449dcb0SKirill A. Shutemov	  to 64-bit linear addresses, allowing software to use of the
22676449dcb0SKirill A. Shutemov	  untranslated address bits for metadata.
22686449dcb0SKirill A. Shutemov
22696449dcb0SKirill A. Shutemov	  The capability can be used for efficient address sanitizers (ASAN)
22706449dcb0SKirill A. Shutemov	  implementation and for optimizations in JITs.
22716449dcb0SKirill A. Shutemov
2272506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2273bebd024eSThomas Gleixner	def_bool y
227440b31360SStephen Rothwell	depends on SMP
2275506f1d07SSam Ravnborg
2276506f1d07SSam Ravnborgconfig COMPAT_VDSO
2277b0b49f26SAndy Lutomirski	def_bool n
2278b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2279953fee1dSIngo Molnar	depends on COMPAT_32
2280a7f7f624SMasahiro Yamada	help
2281b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2282b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2283b0b49f26SAndy Lutomirski	  indicated in its segment table.
2284e84446deSRandy Dunlap
2285b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2286b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2287b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2288b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2289b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2290506f1d07SSam Ravnborg
2291b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2292b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2293b0b49f26SAndy Lutomirski
2294b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2295b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2296b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2297b0b49f26SAndy Lutomirski
2298b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2299b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2300506f1d07SSam Ravnborg
23013dc33bd3SKees Cookchoice
23023dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23033dc33bd3SKees Cook	depends on X86_64
2304625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23053dc33bd3SKees Cook	help
23063dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23073dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23083dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23093dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23103dc33bd3SKees Cook
23113dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2312bf00745eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2313bf00745eSAndy Lutomirski	  is deprecated and can only be enabled using the kernel command
2314bf00745eSAndy Lutomirski	  line.
23153dc33bd3SKees Cook
23163dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23173dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23183dc33bd3SKees Cook	  to improve security.
23193dc33bd3SKees Cook
2320bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23213dc33bd3SKees Cook
2322bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2323bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2324bd49e16eSAndy Lutomirski		help
2325bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2326bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2327bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2328bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2329bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2330bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2331bd49e16eSAndy Lutomirski		  buffer.
23323dc33bd3SKees Cook
23333dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23343dc33bd3SKees Cook		bool "None"
23353dc33bd3SKees Cook		help
23363dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23373dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23383dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23393dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23403dc33bd3SKees Cook		  malicious userspace programs can be identified.
23413dc33bd3SKees Cook
23423dc33bd3SKees Cookendchoice
23433dc33bd3SKees Cook
2344516cbf37STim Birdconfig CMDLINE_BOOL
2345516cbf37STim Bird	bool "Built-in kernel command line"
2346a7f7f624SMasahiro Yamada	help
2347516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2348516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2349516cbf37STim Bird	  necessary or convenient to provide some or all of the
2350516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2351516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2352516cbf37STim Bird
2353516cbf37STim Bird	  To compile command line arguments into the kernel,
2354516cbf37STim Bird	  set this option to 'Y', then fill in the
235569711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2356516cbf37STim Bird
2357516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2358516cbf37STim Bird	  should leave this option set to 'N'.
2359516cbf37STim Bird
2360516cbf37STim Birdconfig CMDLINE
2361516cbf37STim Bird	string "Built-in kernel command string"
2362516cbf37STim Bird	depends on CMDLINE_BOOL
2363516cbf37STim Bird	default ""
2364a7f7f624SMasahiro Yamada	help
2365516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2366516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2367516cbf37STim Bird	  command line at boot time, it is appended to this string to
2368516cbf37STim Bird	  form the full kernel command line, when the system boots.
2369516cbf37STim Bird
2370516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2371516cbf37STim Bird	  change this behavior.
2372516cbf37STim Bird
2373516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2374516cbf37STim Bird	  by the boot loader) should specify the device for the root
2375516cbf37STim Bird	  file system.
2376516cbf37STim Bird
2377516cbf37STim Birdconfig CMDLINE_OVERRIDE
2378516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2379645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2380a7f7f624SMasahiro Yamada	help
2381516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2382516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2383516cbf37STim Bird
2384516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2385516cbf37STim Bird	  be set to 'N' under normal conditions.
2386516cbf37STim Bird
2387a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2388a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2389a5b9e5a2SAndy Lutomirski	default y
2390a7f7f624SMasahiro Yamada	help
2391a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2392a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2393a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2394a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2395a5b9e5a2SAndy Lutomirski	  threading libraries.
2396a5b9e5a2SAndy Lutomirski
2397a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2398a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2399a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2400a5b9e5a2SAndy Lutomirski
2401a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2402a5b9e5a2SAndy Lutomirski
24033aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24043aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24053aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24063aac3ebeSThomas Gleixner	help
24073aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24083aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24093aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24103aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24113aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24123aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24133aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24143aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24153aac3ebeSThomas Gleixner	  never get a signal delivered.
24163aac3ebeSThomas Gleixner
24173aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24183aac3ebeSThomas Gleixner
2419d6f635bcSKees Cookconfig CFI_AUTO_DEFAULT
2420d6f635bcSKees Cook	bool "Attempt to use FineIBT by default at boot time"
2421d6f635bcSKees Cook	depends on FINEIBT
2422d6f635bcSKees Cook	default y
2423d6f635bcSKees Cook	help
2424d6f635bcSKees Cook	  Attempt to use FineIBT by default at boot time. If enabled,
2425d6f635bcSKees Cook	  this is the same as booting with "cfi=auto". If disabled,
2426d6f635bcSKees Cook	  this is the same as booting with "cfi=kcfi".
2427d6f635bcSKees Cook
2428b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2429b700e7f0SSeth Jennings
2430506f1d07SSam Ravnborgendmenu
2431506f1d07SSam Ravnborg
24321ca3683cSUros Bizjakconfig CC_HAS_NAMED_AS
243347ff30ccSUros Bizjak	def_bool $(success,echo 'int __seg_fs fs; int __seg_gs gs;' | $(CC) -x c - -S -o /dev/null)
243447ff30ccSUros Bizjak	depends on CC_IS_GCC
24351ca3683cSUros Bizjak
24369ebe5500SUros Bizjakconfig CC_HAS_NAMED_AS_FIXED_SANITIZERS
2437f61f02d1SUros Bizjak	def_bool CC_IS_GCC && GCC_VERSION >= 130300
24381ca3683cSUros Bizjak
24391ca3683cSUros Bizjakconfig USE_X86_SEG_SUPPORT
24401ca3683cSUros Bizjak	def_bool y
2441e29aad08SUros Bizjak	depends on CC_HAS_NAMED_AS
2442e29aad08SUros Bizjak	#
24439ebe5500SUros Bizjak	# -fsanitize=kernel-address (KASAN) and -fsanitize=thread
24449ebe5500SUros Bizjak	# (KCSAN) are incompatible with named address spaces with
24459ebe5500SUros Bizjak	# GCC < 13.3 - see GCC PR sanitizer/111736.
2446e29aad08SUros Bizjak	#
24479ebe5500SUros Bizjak	depends on !(KASAN || KCSAN) || CC_HAS_NAMED_AS_FIXED_SANITIZERS
24481ca3683cSUros Bizjak
2449f43b9876SPeter Zijlstraconfig CC_HAS_SLS
2450f43b9876SPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
2451f43b9876SPeter Zijlstra
2452f43b9876SPeter Zijlstraconfig CC_HAS_RETURN_THUNK
2453f43b9876SPeter Zijlstra	def_bool $(cc-option,-mfunction-return=thunk-extern)
2454f43b9876SPeter Zijlstra
2455bea75b33SThomas Gleixnerconfig CC_HAS_ENTRY_PADDING
2456bea75b33SThomas Gleixner	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2457bea75b33SThomas Gleixner
2458bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_CFI
2459bea75b33SThomas Gleixner	int
2460bea75b33SThomas Gleixner	default 59 if FUNCTION_ALIGNMENT_64B
2461bea75b33SThomas Gleixner	default 27 if FUNCTION_ALIGNMENT_32B
2462bea75b33SThomas Gleixner	default 11 if FUNCTION_ALIGNMENT_16B
2463bea75b33SThomas Gleixner	default  3 if FUNCTION_ALIGNMENT_8B
2464bea75b33SThomas Gleixner	default  0
2465bea75b33SThomas Gleixner
2466bea75b33SThomas Gleixner# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2467bea75b33SThomas Gleixner# except Kconfig can't do arithmetic :/
2468bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_BYTES
2469bea75b33SThomas Gleixner	int
2470bea75b33SThomas Gleixner	default FUNCTION_PADDING_CFI if CFI_CLANG
2471bea75b33SThomas Gleixner	default FUNCTION_ALIGNMENT
2472bea75b33SThomas Gleixner
2473931ab636SPeter Zijlstraconfig CALL_PADDING
2474931ab636SPeter Zijlstra	def_bool n
2475931ab636SPeter Zijlstra	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2476931ab636SPeter Zijlstra	select FUNCTION_ALIGNMENT_16B
2477931ab636SPeter Zijlstra
2478931ab636SPeter Zijlstraconfig FINEIBT
2479931ab636SPeter Zijlstra	def_bool y
2480aefb2f2eSBreno Leitao	depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE
2481931ab636SPeter Zijlstra	select CALL_PADDING
2482931ab636SPeter Zijlstra
24838f7c0d8bSThomas Gleixnerconfig HAVE_CALL_THUNKS
24848f7c0d8bSThomas Gleixner	def_bool y
24850911b8c5SBreno Leitao	depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL
24868f7c0d8bSThomas Gleixner
24878f7c0d8bSThomas Gleixnerconfig CALL_THUNKS
24888f7c0d8bSThomas Gleixner	def_bool n
2489931ab636SPeter Zijlstra	select CALL_PADDING
24908f7c0d8bSThomas Gleixner
2491b341b20dSPeter Zijlstraconfig PREFIX_SYMBOLS
2492b341b20dSPeter Zijlstra	def_bool y
2493931ab636SPeter Zijlstra	depends on CALL_PADDING && !CFI_CLANG
2494b341b20dSPeter Zijlstra
2495fe42754bSSean Christophersonmenuconfig CPU_MITIGATIONS
2496fe42754bSSean Christopherson	bool "Mitigations for CPU vulnerabilities"
2497f43b9876SPeter Zijlstra	default y
2498f43b9876SPeter Zijlstra	help
2499fe42754bSSean Christopherson	  Say Y here to enable options which enable mitigations for hardware
2500fe42754bSSean Christopherson	  vulnerabilities (usually related to speculative execution).
2501ce0abef6SSean Christopherson	  Mitigations can be disabled or restricted to SMT systems at runtime
2502ce0abef6SSean Christopherson	  via the "mitigations" kernel parameter.
2503f43b9876SPeter Zijlstra
2504ce0abef6SSean Christopherson	  If you say N, all mitigations will be disabled.  This CANNOT be
2505ce0abef6SSean Christopherson	  overridden at runtime.
2506ce0abef6SSean Christopherson
2507ce0abef6SSean Christopherson	  Say 'Y', unless you really know what you are doing.
2508f43b9876SPeter Zijlstra
2509fe42754bSSean Christophersonif CPU_MITIGATIONS
2510f43b9876SPeter Zijlstra
2511ea4654e0SBreno Leitaoconfig MITIGATION_PAGE_TABLE_ISOLATION
2512f43b9876SPeter Zijlstra	bool "Remove the kernel mapping in user mode"
2513f43b9876SPeter Zijlstra	default y
2514f43b9876SPeter Zijlstra	depends on (X86_64 || X86_PAE)
2515f43b9876SPeter Zijlstra	help
2516f43b9876SPeter Zijlstra	  This feature reduces the number of hardware side channels by
2517f43b9876SPeter Zijlstra	  ensuring that the majority of kernel addresses are not mapped
2518f43b9876SPeter Zijlstra	  into userspace.
2519f43b9876SPeter Zijlstra
2520ff61f079SJonathan Corbet	  See Documentation/arch/x86/pti.rst for more details.
2521f43b9876SPeter Zijlstra
2522aefb2f2eSBreno Leitaoconfig MITIGATION_RETPOLINE
2523f43b9876SPeter Zijlstra	bool "Avoid speculative indirect branches in kernel"
2524f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2525f43b9876SPeter Zijlstra	default y
2526f43b9876SPeter Zijlstra	help
2527f43b9876SPeter Zijlstra	  Compile kernel with the retpoline compiler options to guard against
2528f43b9876SPeter Zijlstra	  kernel-to-user data leaks by avoiding speculative indirect
2529f43b9876SPeter Zijlstra	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2530f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2531f43b9876SPeter Zijlstra
25320911b8c5SBreno Leitaoconfig MITIGATION_RETHUNK
2533f43b9876SPeter Zijlstra	bool "Enable return-thunks"
2534aefb2f2eSBreno Leitao	depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK
2535f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2536b648ab48SBen Hutchings	default y if X86_64
2537f43b9876SPeter Zijlstra	help
2538f43b9876SPeter Zijlstra	  Compile the kernel with the return-thunks compiler option to guard
2539f43b9876SPeter Zijlstra	  against kernel-to-user data leaks by avoiding return speculation.
2540f43b9876SPeter Zijlstra	  Requires a compiler with -mfunction-return=thunk-extern
2541f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2542f43b9876SPeter Zijlstra
2543ac61d439SBreno Leitaoconfig MITIGATION_UNRET_ENTRY
2544f43b9876SPeter Zijlstra	bool "Enable UNRET on kernel entry"
25450911b8c5SBreno Leitao	depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64
2546f43b9876SPeter Zijlstra	default y
2547f43b9876SPeter Zijlstra	help
2548f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=unret mitigation.
2549f43b9876SPeter Zijlstra
25505fa31af3SBreno Leitaoconfig MITIGATION_CALL_DEPTH_TRACKING
255180e4c1cdSThomas Gleixner	bool "Mitigate RSB underflow with call depth tracking"
255280e4c1cdSThomas Gleixner	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
255380e4c1cdSThomas Gleixner	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
255480e4c1cdSThomas Gleixner	select CALL_THUNKS
255580e4c1cdSThomas Gleixner	default y
255680e4c1cdSThomas Gleixner	help
255780e4c1cdSThomas Gleixner	  Compile the kernel with call depth tracking to mitigate the Intel
255880e4c1cdSThomas Gleixner	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
255980e4c1cdSThomas Gleixner	  mitigation is off by default and needs to be enabled on the
256080e4c1cdSThomas Gleixner	  kernel command line via the retbleed=stuff option. For
256180e4c1cdSThomas Gleixner	  non-affected systems the overhead of this option is marginal as
256280e4c1cdSThomas Gleixner	  the call depth tracking is using run-time generated call thunks
256380e4c1cdSThomas Gleixner	  in a compiler generated padding area and call patching. This
256480e4c1cdSThomas Gleixner	  increases text size by ~5%. For non affected systems this space
256580e4c1cdSThomas Gleixner	  is unused. On affected SKL systems this results in a significant
256680e4c1cdSThomas Gleixner	  performance gain over the IBRS mitigation.
256780e4c1cdSThomas Gleixner
2568e81dc127SThomas Gleixnerconfig CALL_THUNKS_DEBUG
2569e81dc127SThomas Gleixner	bool "Enable call thunks and call depth tracking debugging"
25705fa31af3SBreno Leitao	depends on MITIGATION_CALL_DEPTH_TRACKING
2571e81dc127SThomas Gleixner	select FUNCTION_ALIGNMENT_32B
2572e81dc127SThomas Gleixner	default n
2573e81dc127SThomas Gleixner	help
2574e81dc127SThomas Gleixner	  Enable call/ret counters for imbalance detection and build in
2575e81dc127SThomas Gleixner	  a noisy dmesg about callthunks generation and call patching for
2576e81dc127SThomas Gleixner	  trouble shooting. The debug prints need to be enabled on the
2577e81dc127SThomas Gleixner	  kernel command line with 'debug-callthunks'.
257854628de6SRandy Dunlap	  Only enable this when you are debugging call thunks as this
257954628de6SRandy Dunlap	  creates a noticeable runtime overhead. If unsure say N.
258080e4c1cdSThomas Gleixner
2581e0b8fcfaSBreno Leitaoconfig MITIGATION_IBPB_ENTRY
2582f43b9876SPeter Zijlstra	bool "Enable IBPB on kernel entry"
2583b648ab48SBen Hutchings	depends on CPU_SUP_AMD && X86_64
2584f43b9876SPeter Zijlstra	default y
2585f43b9876SPeter Zijlstra	help
2586f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=ibpb mitigation.
2587f43b9876SPeter Zijlstra
25881da8d217SBreno Leitaoconfig MITIGATION_IBRS_ENTRY
2589f43b9876SPeter Zijlstra	bool "Enable IBRS on kernel entry"
2590b648ab48SBen Hutchings	depends on CPU_SUP_INTEL && X86_64
2591f43b9876SPeter Zijlstra	default y
2592f43b9876SPeter Zijlstra	help
2593f43b9876SPeter Zijlstra	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2594f43b9876SPeter Zijlstra	  This mitigates both spectre_v2 and retbleed at great cost to
2595f43b9876SPeter Zijlstra	  performance.
2596f43b9876SPeter Zijlstra
2597a033eec9SBreno Leitaoconfig MITIGATION_SRSO
2598fb3bd914SBorislav Petkov (AMD)	bool "Mitigate speculative RAS overflow on AMD"
25990911b8c5SBreno Leitao	depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK
2600fb3bd914SBorislav Petkov (AMD)	default y
2601fb3bd914SBorislav Petkov (AMD)	help
2602fb3bd914SBorislav Petkov (AMD)	  Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2603fb3bd914SBorislav Petkov (AMD)
26047b75782fSBreno Leitaoconfig MITIGATION_SLS
2605f43b9876SPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
2606f43b9876SPeter Zijlstra	depends on CC_HAS_SLS && X86_64
2607f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2608f43b9876SPeter Zijlstra	default n
2609f43b9876SPeter Zijlstra	help
2610f43b9876SPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
2611f43b9876SPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
2612f43b9876SPeter Zijlstra	  larger.
2613f43b9876SPeter Zijlstra
2614225f2bd0SBreno Leitaoconfig MITIGATION_GDS
2615225f2bd0SBreno Leitao	bool "Mitigate Gather Data Sampling"
2616225f2bd0SBreno Leitao	depends on CPU_SUP_INTEL
2617225f2bd0SBreno Leitao	default y
2618225f2bd0SBreno Leitao	help
2619225f2bd0SBreno Leitao	  Enable mitigation for Gather Data Sampling (GDS). GDS is a hardware
2620225f2bd0SBreno Leitao	  vulnerability which allows unprivileged speculative access to data
2621225f2bd0SBreno Leitao	  which was previously stored in vector registers. The attacker uses gather
2622225f2bd0SBreno Leitao	  instructions to infer the stale vector register data.
2623225f2bd0SBreno Leitao
26248076fcdeSPawan Guptaconfig MITIGATION_RFDS
26258076fcdeSPawan Gupta	bool "RFDS Mitigation"
26268076fcdeSPawan Gupta	depends on CPU_SUP_INTEL
26278076fcdeSPawan Gupta	default y
26288076fcdeSPawan Gupta	help
26298076fcdeSPawan Gupta	  Enable mitigation for Register File Data Sampling (RFDS) by default.
26308076fcdeSPawan Gupta	  RFDS is a hardware vulnerability which affects Intel Atom CPUs. It
26318076fcdeSPawan Gupta	  allows unprivileged speculative access to stale data previously
26328076fcdeSPawan Gupta	  stored in floating point, vector and integer registers.
26338076fcdeSPawan Gupta	  See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>
26348076fcdeSPawan Gupta
26354f511739SJosh Poimboeufconfig MITIGATION_SPECTRE_BHI
26364f511739SJosh Poimboeuf	bool "Mitigate Spectre-BHB (Branch History Injection)"
2637ec9404e4SPawan Gupta	depends on CPU_SUP_INTEL
26384f511739SJosh Poimboeuf	default y
2639ec9404e4SPawan Gupta	help
2640ec9404e4SPawan Gupta	  Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
2641ec9404e4SPawan Gupta	  where the branch history buffer is poisoned to speculatively steer
2642ec9404e4SPawan Gupta	  indirect branches.
2643ec9404e4SPawan Gupta	  See <file:Documentation/admin-guide/hw-vuln/spectre.rst>
2644ec9404e4SPawan Gupta
264594045568SBreno Leitaoconfig MITIGATION_MDS
264694045568SBreno Leitao	bool "Mitigate Microarchitectural Data Sampling (MDS) hardware bug"
264794045568SBreno Leitao	depends on CPU_SUP_INTEL
264894045568SBreno Leitao	default y
264994045568SBreno Leitao	help
265094045568SBreno Leitao	  Enable mitigation for Microarchitectural Data Sampling (MDS). MDS is
265194045568SBreno Leitao	  a hardware vulnerability which allows unprivileged speculative access
265294045568SBreno Leitao	  to data which is available in various CPU internal buffers.
265394045568SBreno Leitao	  See also <file:Documentation/admin-guide/hw-vuln/mds.rst>
2654b8da0b33SBreno Leitao
2655b8da0b33SBreno Leitaoconfig MITIGATION_TAA
2656b8da0b33SBreno Leitao	bool "Mitigate TSX Asynchronous Abort (TAA) hardware bug"
2657b8da0b33SBreno Leitao	depends on CPU_SUP_INTEL
2658b8da0b33SBreno Leitao	default y
2659b8da0b33SBreno Leitao	help
2660b8da0b33SBreno Leitao	  Enable mitigation for TSX Asynchronous Abort (TAA). TAA is a hardware
2661b8da0b33SBreno Leitao	  vulnerability that allows unprivileged speculative access to data
2662b8da0b33SBreno Leitao	  which is available in various CPU internal buffers by using
2663b8da0b33SBreno Leitao	  asynchronous aborts within an Intel TSX transactional region.
2664b8da0b33SBreno Leitao	  See also <file:Documentation/admin-guide/hw-vuln/tsx_async_abort.rst>
2665163f9fe6SBreno Leitao
2666163f9fe6SBreno Leitaoconfig MITIGATION_MMIO_STALE_DATA
2667163f9fe6SBreno Leitao	bool "Mitigate MMIO Stale Data hardware bug"
2668163f9fe6SBreno Leitao	depends on CPU_SUP_INTEL
2669163f9fe6SBreno Leitao	default y
2670163f9fe6SBreno Leitao	help
2671163f9fe6SBreno Leitao	  Enable mitigation for MMIO Stale Data hardware bugs.  Processor MMIO
2672163f9fe6SBreno Leitao	  Stale Data Vulnerabilities are a class of memory-mapped I/O (MMIO)
2673163f9fe6SBreno Leitao	  vulnerabilities that can expose data. The vulnerabilities require the
2674163f9fe6SBreno Leitao	  attacker to have access to MMIO.
2675163f9fe6SBreno Leitao	  See also
2676163f9fe6SBreno Leitao	  <file:Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst>
26773a4ee4ffSBreno Leitao
26783a4ee4ffSBreno Leitaoconfig MITIGATION_L1TF
26793a4ee4ffSBreno Leitao	bool "Mitigate L1 Terminal Fault (L1TF) hardware bug"
26803a4ee4ffSBreno Leitao	depends on CPU_SUP_INTEL
26813a4ee4ffSBreno Leitao	default y
26823a4ee4ffSBreno Leitao	help
26833a4ee4ffSBreno Leitao	  Mitigate L1 Terminal Fault (L1TF) hardware bug. L1 Terminal Fault is a
26843a4ee4ffSBreno Leitao	  hardware vulnerability which allows unprivileged speculative access to data
26853a4ee4ffSBreno Leitao	  available in the Level 1 Data Cache.
26863a4ee4ffSBreno Leitao	  See <file:Documentation/admin-guide/hw-vuln/l1tf.rst
2687894e2885SBreno Leitao
2688894e2885SBreno Leitaoconfig MITIGATION_RETBLEED
2689894e2885SBreno Leitao	bool "Mitigate RETBleed hardware bug"
2690894e2885SBreno Leitao	depends on (CPU_SUP_INTEL && MITIGATION_SPECTRE_V2) || MITIGATION_UNRET_ENTRY || MITIGATION_IBPB_ENTRY
2691894e2885SBreno Leitao	default y
2692894e2885SBreno Leitao	help
2693894e2885SBreno Leitao	  Enable mitigation for RETBleed (Arbitrary Speculative Code Execution
2694894e2885SBreno Leitao	  with Return Instructions) vulnerability.  RETBleed is a speculative
2695894e2885SBreno Leitao	  execution attack which takes advantage of microarchitectural behavior
2696894e2885SBreno Leitao	  in many modern microprocessors, similar to Spectre v2. An
2697894e2885SBreno Leitao	  unprivileged attacker can use these flaws to bypass conventional
2698894e2885SBreno Leitao	  memory security restrictions to gain read access to privileged memory
2699894e2885SBreno Leitao	  that would otherwise be inaccessible.
2700ca01c0d8SBreno Leitao
2701ca01c0d8SBreno Leitaoconfig MITIGATION_SPECTRE_V1
2702ca01c0d8SBreno Leitao	bool "Mitigate SPECTRE V1 hardware bug"
2703ca01c0d8SBreno Leitao	default y
2704ca01c0d8SBreno Leitao	help
2705ca01c0d8SBreno Leitao	  Enable mitigation for Spectre V1 (Bounds Check Bypass). Spectre V1 is a
2706ca01c0d8SBreno Leitao	  class of side channel attacks that takes advantage of speculative
2707ca01c0d8SBreno Leitao	  execution that bypasses conditional branch instructions used for
2708ca01c0d8SBreno Leitao	  memory access bounds check.
2709ca01c0d8SBreno Leitao	  See also <file:Documentation/admin-guide/hw-vuln/spectre.rst>
2710a0b02e3fSBreno Leitao
271172c70f48SBreno Leitaoconfig MITIGATION_SPECTRE_V2
271272c70f48SBreno Leitao	bool "Mitigate SPECTRE V2 hardware bug"
271372c70f48SBreno Leitao	default y
271472c70f48SBreno Leitao	help
271572c70f48SBreno Leitao	  Enable mitigation for Spectre V2 (Branch Target Injection). Spectre
271672c70f48SBreno Leitao	  V2 is a class of side channel attacks that takes advantage of
271772c70f48SBreno Leitao	  indirect branch predictors inside the processor. In Spectre variant 2
271872c70f48SBreno Leitao	  attacks, the attacker can steer speculative indirect branches in the
271972c70f48SBreno Leitao	  victim to gadget code by poisoning the branch target buffer of a CPU
272072c70f48SBreno Leitao	  used for predicting indirect branch addresses.
272172c70f48SBreno Leitao	  See also <file:Documentation/admin-guide/hw-vuln/spectre.rst>
272272c70f48SBreno Leitao
2723a0b02e3fSBreno Leitaoconfig MITIGATION_SRBDS
2724a0b02e3fSBreno Leitao	bool "Mitigate Special Register Buffer Data Sampling (SRBDS) hardware bug"
2725a0b02e3fSBreno Leitao	depends on CPU_SUP_INTEL
2726a0b02e3fSBreno Leitao	default y
2727a0b02e3fSBreno Leitao	help
2728a0b02e3fSBreno Leitao	  Enable mitigation for Special Register Buffer Data Sampling (SRBDS).
2729a0b02e3fSBreno Leitao	  SRBDS is a hardware vulnerability that allows Microarchitectural Data
2730a0b02e3fSBreno Leitao	  Sampling (MDS) techniques to infer values returned from special
2731a0b02e3fSBreno Leitao	  register accesses. An unprivileged user can extract values returned
2732a0b02e3fSBreno Leitao	  from RDRAND and RDSEED executed on another core or sibling thread
2733a0b02e3fSBreno Leitao	  using MDS techniques.
2734a0b02e3fSBreno Leitao	  See also
2735a0b02e3fSBreno Leitao	  <file:Documentation/admin-guide/hw-vuln/special-register-buffer-data-sampling.rst>
2736b908cdabSBreno Leitao
2737b908cdabSBreno Leitaoconfig MITIGATION_SSB
2738b908cdabSBreno Leitao	bool "Mitigate Speculative Store Bypass (SSB) hardware bug"
2739b908cdabSBreno Leitao	default y
2740b908cdabSBreno Leitao	help
2741b908cdabSBreno Leitao	  Enable mitigation for Speculative Store Bypass (SSB). SSB is a
2742b908cdabSBreno Leitao	  hardware security vulnerability and its exploitation takes advantage
2743b908cdabSBreno Leitao	  of speculative execution in a similar way to the Meltdown and Spectre
2744b908cdabSBreno Leitao	  security vulnerabilities.
2745b908cdabSBreno Leitao
2746f43b9876SPeter Zijlstraendif
2747f43b9876SPeter Zijlstra
27483072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
27493072e413SMichal Hocko	def_bool y
27505c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
27513072e413SMichal Hocko
2752da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2753e279b6c1SSam Ravnborg
2754e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
27553c2362e6SHarvey Harrison	def_bool y
275644556530SZhimin Gu	depends on HIBERNATION
2757e279b6c1SSam Ravnborg
2758e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2759e279b6c1SSam Ravnborg
2760e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2761e279b6c1SSam Ravnborg
2762a6b68076SAndi Kleenconfig X86_APM_BOOT
27636fc108a0SJan Beulich	def_bool y
2764282e5aabSPaul Bolle	depends on APM
2765a6b68076SAndi Kleen
2766e279b6c1SSam Ravnborgmenuconfig APM
2767e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2768efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2769a7f7f624SMasahiro Yamada	help
2770e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2771e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2772e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2773e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2774e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2775e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2776e279b6c1SSam Ravnborg
2777e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2778e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2779e279b6c1SSam Ravnborg
2780e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2781e279b6c1SSam Ravnborg	  machines with more than one CPU.
2782e279b6c1SSam Ravnborg
2783e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2784151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
27852dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2786e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2787e279b6c1SSam Ravnborg
2788e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2789e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2790e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2791e279b6c1SSam Ravnborg
2792e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2793e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2794e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2795e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2796e279b6c1SSam Ravnborg
2797e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2798e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2799e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2800e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2801e279b6c1SSam Ravnborg	  APM in your BIOS).
2802e279b6c1SSam Ravnborg
2803e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2804e279b6c1SSam Ravnborg	  "weird" problems:
2805e279b6c1SSam Ravnborg
2806e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2807e279b6c1SSam Ravnborg	  enabled.
28087987448fSStephen Kitt	  2) pass the "idle=poll" option to the kernel
2809e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2810e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2811e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2812e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2813e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2814e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2815e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2816e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2817e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2818e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2819e279b6c1SSam Ravnborg	  11) exchange RAM chips
2820e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2821e279b6c1SSam Ravnborg
2822e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2823e279b6c1SSam Ravnborg	  module will be called apm.
2824e279b6c1SSam Ravnborg
2825e279b6c1SSam Ravnborgif APM
2826e279b6c1SSam Ravnborg
2827e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2828e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2829a7f7f624SMasahiro Yamada	help
2830e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2831e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2832e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2833e279b6c1SSam Ravnborg
2834e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2835e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2836a7f7f624SMasahiro Yamada	help
2837e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2838e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2839e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2840e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2841e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2842e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2843e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2844e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2845e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2846e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2847e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2848e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2849e279b6c1SSam Ravnborg	  this feature.
2850e279b6c1SSam Ravnborg
2851e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2852dd8af076SLen Brown	depends on CPU_IDLE
2853e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2854a7f7f624SMasahiro Yamada	help
2855e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2856e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2857e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2858e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2859e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2860e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2861e279b6c1SSam Ravnborg	  this option does nothing.)
2862e279b6c1SSam Ravnborg
2863e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2864e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2865a7f7f624SMasahiro Yamada	help
2866e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2867e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2868e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2869e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2870e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2871e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2872e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2873e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2874e279b6c1SSam Ravnborg	  especially if you are using gpm.
2875e279b6c1SSam Ravnborg
2876e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2877e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2878a7f7f624SMasahiro Yamada	help
2879e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2880e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2881e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2882e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2883e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2884e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2885e279b6c1SSam Ravnborg
2886e279b6c1SSam Ravnborgendif # APM
2887e279b6c1SSam Ravnborg
2888bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2889e279b6c1SSam Ravnborg
2890e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2891e279b6c1SSam Ravnborg
289227471fdbSAndy Henroidsource "drivers/idle/Kconfig"
289327471fdbSAndy Henroid
2894e279b6c1SSam Ravnborgendmenu
2895e279b6c1SSam Ravnborg
2896e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2897e279b6c1SSam Ravnborg
2898e279b6c1SSam Ravnborgchoice
2899e279b6c1SSam Ravnborg	prompt "PCI access mode"
2900efefa6f6SIngo Molnar	depends on X86_32 && PCI
2901e279b6c1SSam Ravnborg	default PCI_GOANY
2902a7f7f624SMasahiro Yamada	help
2903e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2904e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2905e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2906e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2907e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2908e279b6c1SSam Ravnborg
2909e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2910e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2911e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2912e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2913e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2914e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2915e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2916e279b6c1SSam Ravnborg
2917e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2918e279b6c1SSam Ravnborg	bool "BIOS"
2919e279b6c1SSam Ravnborg
2920e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2921e279b6c1SSam Ravnborg	bool "MMConfig"
2922e279b6c1SSam Ravnborg
2923e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2924e279b6c1SSam Ravnborg	bool "Direct"
2925e279b6c1SSam Ravnborg
29263ef0e1f8SAndres Salomonconfig PCI_GOOLPC
292776fb6570SDaniel Drake	bool "OLPC XO-1"
29283ef0e1f8SAndres Salomon	depends on OLPC
29293ef0e1f8SAndres Salomon
29302bdd1b03SAndres Salomonconfig PCI_GOANY
29312bdd1b03SAndres Salomon	bool "Any"
29322bdd1b03SAndres Salomon
2933e279b6c1SSam Ravnborgendchoice
2934e279b6c1SSam Ravnborg
2935e279b6c1SSam Ravnborgconfig PCI_BIOS
29363c2362e6SHarvey Harrison	def_bool y
2937efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2938e279b6c1SSam Ravnborg
2939e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2940e279b6c1SSam Ravnborgconfig PCI_DIRECT
29413c2362e6SHarvey Harrison	def_bool y
29420aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2943e279b6c1SSam Ravnborg
2944e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2945b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2946b45c9f36SJan Kiszka	default y
29474590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2948b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2949e279b6c1SSam Ravnborg
29503ef0e1f8SAndres Salomonconfig PCI_OLPC
29512bdd1b03SAndres Salomon	def_bool y
29522bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
29533ef0e1f8SAndres Salomon
2954b5401a96SAlex Nixonconfig PCI_XEN
2955b5401a96SAlex Nixon	def_bool y
2956b5401a96SAlex Nixon	depends on PCI && XEN
2957b5401a96SAlex Nixon
29588364e1f8SJan Kiszkaconfig MMCONF_FAM10H
29598364e1f8SJan Kiszka	def_bool y
29608364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2961e279b6c1SSam Ravnborg
29623f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
29636a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
29646ea30386SKees Cook	depends on PCI
29653f6ea84aSIra W. Snyder	help
29663f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
29673f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
29683f6ea84aSIra W. Snyder	  not have ACPI.
29693f6ea84aSIra W. Snyder
297064a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
297164a5fed6SBjorn Helgaas	  is known to be incomplete.
297264a5fed6SBjorn Helgaas
297364a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
297464a5fed6SBjorn Helgaas
29753a495511SWilliam Breathitt Grayconfig ISA_BUS
297617a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
29773a495511SWilliam Breathitt Gray	help
297817a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
297917a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
298017a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
298117a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
298217a2a129SWilliam Breathitt Gray	  not have an ISA bus.
29833a495511SWilliam Breathitt Gray
29843a495511SWilliam Breathitt Gray	  If unsure, say N.
29853a495511SWilliam Breathitt Gray
29861c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2987e279b6c1SSam Ravnborgconfig ISA_DMA_API
29881c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
29891c00f016SDavid Rientjes	default y
29901c00f016SDavid Rientjes	help
29911c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
29921c00f016SDavid Rientjes	  If unsure, say Y.
2993e279b6c1SSam Ravnborg
299451e68d05SLinus Torvaldsif X86_32
299551e68d05SLinus Torvalds
2996e279b6c1SSam Ravnborgconfig ISA
2997e279b6c1SSam Ravnborg	bool "ISA support"
2998a7f7f624SMasahiro Yamada	help
2999e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
3000e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
3001e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
3002e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
3003e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
3004e279b6c1SSam Ravnborg
3005e279b6c1SSam Ravnborgconfig SCx200
3006e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
3007a7f7f624SMasahiro Yamada	help
3008e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
3009e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
3010e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
3011e279b6c1SSam Ravnborg	  for other scx200_* drivers.
3012e279b6c1SSam Ravnborg
3013e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
3014e279b6c1SSam Ravnborg
3015e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
3016e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
3017592913ecSJohn Stultz	depends on SCx200
3018e279b6c1SSam Ravnborg	default y
3019a7f7f624SMasahiro Yamada	help
3020e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
3021e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
3022e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
3023e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
3024e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
3025e279b6c1SSam Ravnborg
30263ef0e1f8SAndres Salomonconfig OLPC
30273ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
302854008979SThomas Gleixner	depends on !X86_PAE
30293c554946SAndres Salomon	select GPIOLIB
3030dc3119e7SThomas Gleixner	select OF
303145bb1674SDaniel Drake	select OF_PROMTREE
3032b4e51854SGrant Likely	select IRQ_DOMAIN
30330c3d931bSLubomir Rintel	select OLPC_EC
3034a7f7f624SMasahiro Yamada	help
30353ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
30363ef0e1f8SAndres Salomon	  XO hardware.
30373ef0e1f8SAndres Salomon
3038a3128588SDaniel Drakeconfig OLPC_XO1_PM
3039a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
3040fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
3041a7f7f624SMasahiro Yamada	help
304297c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
3043bf1ebf00SDaniel Drake
3044cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
3045cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
3046cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
3047a7f7f624SMasahiro Yamada	help
3048cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
3049cfee9597SDaniel Drake	  programmable wakeup source.
3050cfee9597SDaniel Drake
30517feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
30527feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
305392e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
3054ed8e47feSRandy Dunlap	depends on INPUT=y
3055d8d01a63SDaniel Drake	select POWER_SUPPLY
3056a7f7f624SMasahiro Yamada	help
30577feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
30587bc74b3dSDaniel Drake	   - EC-driven system wakeups
30597feda8e9SDaniel Drake	   - Power button
30607bc74b3dSDaniel Drake	   - Ebook switch
30612cf2baeaSDaniel Drake	   - Lid switch
3062e1040ac6SDaniel Drake	   - AC adapter status updates
3063e1040ac6SDaniel Drake	   - Battery status updates
30647feda8e9SDaniel Drake
3065a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
3066a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
3067d8d01a63SDaniel Drake	depends on OLPC && ACPI
3068d8d01a63SDaniel Drake	select POWER_SUPPLY
3069a7f7f624SMasahiro Yamada	help
3070a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
3071a0f30f59SDaniel Drake	   - EC-driven system wakeups
3072a0f30f59SDaniel Drake	   - AC adapter status updates
3073a0f30f59SDaniel Drake	   - Battery status updates
3074e279b6c1SSam Ravnborg
3075298c9babSDmitry Torokhovconfig GEODE_COMMON
3076298c9babSDmitry Torokhov	bool
3077298c9babSDmitry Torokhov
3078d4f3e350SEd Wildgooseconfig ALIX
3079d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
3080d4f3e350SEd Wildgoose	select GPIOLIB
3081298c9babSDmitry Torokhov	select GEODE_COMMON
3082a7f7f624SMasahiro Yamada	help
3083d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
3084d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
3085d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
3086d4f3e350SEd Wildgoose	  get added here.
3087d4f3e350SEd Wildgoose
3088d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
3089d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
3090d4f3e350SEd Wildgoose
3091d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
3092d4f3e350SEd Wildgoose
3093da4e3302SPhilip Prindevilleconfig NET5501
3094da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
3095da4e3302SPhilip Prindeville	select GPIOLIB
3096298c9babSDmitry Torokhov	select GEODE_COMMON
3097a7f7f624SMasahiro Yamada	help
3098da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
3099da4e3302SPhilip Prindeville
31003197059aSPhilip A. Prindevilleconfig GEOS
31013197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
31023197059aSPhilip A. Prindeville	select GPIOLIB
3103298c9babSDmitry Torokhov	select GEODE_COMMON
31043197059aSPhilip A. Prindeville	depends on DMI
3105a7f7f624SMasahiro Yamada	help
31063197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
31073197059aSPhilip A. Prindeville
31087d029125SVivien Didelotconfig TS5500
31097d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
31107d029125SVivien Didelot	depends on MELAN
31117d029125SVivien Didelot	select CHECK_SIGNATURE
31127d029125SVivien Didelot	select NEW_LEDS
31137d029125SVivien Didelot	select LEDS_CLASS
3114a7f7f624SMasahiro Yamada	help
31157d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
31167d029125SVivien Didelot
3117e279b6c1SSam Ravnborgendif # X86_32
3118e279b6c1SSam Ravnborg
311923ac4ae8SAndreas Herrmannconfig AMD_NB
3120e279b6c1SSam Ravnborg	def_bool y
31210e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
3122e279b6c1SSam Ravnborg
3123e279b6c1SSam Ravnborgendmenu
3124e279b6c1SSam Ravnborg
31251572497cSChristoph Hellwigmenu "Binary Emulations"
3126e279b6c1SSam Ravnborg
3127e279b6c1SSam Ravnborgconfig IA32_EMULATION
3128e279b6c1SSam Ravnborg	bool "IA32 Emulation"
3129e279b6c1SSam Ravnborg	depends on X86_64
313039f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
3131d1603990SRandy Dunlap	select BINFMT_ELF
313239f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
3133a7f7f624SMasahiro Yamada	help
31345fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
31355fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
31365fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
3137e279b6c1SSam Ravnborg
3138a11e0975SNikolay Borisovconfig IA32_EMULATION_DEFAULT_DISABLED
3139a11e0975SNikolay Borisov	bool "IA32 emulation disabled by default"
3140a11e0975SNikolay Borisov	default n
3141a11e0975SNikolay Borisov	depends on IA32_EMULATION
3142a11e0975SNikolay Borisov	help
3143a11e0975SNikolay Borisov	  Make IA32 emulation disabled by default. This prevents loading 32-bit
3144a11e0975SNikolay Borisov	  processes and access to 32-bit syscalls. If unsure, leave it to its
3145a11e0975SNikolay Borisov	  default value.
3146a11e0975SNikolay Borisov
314783a44a4fSMasahiro Yamadaconfig X86_X32_ABI
31486ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
31499b54050bSBrian Gerst	depends on X86_64
3150aaeed6ecSNathan Chancellor	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3151aaeed6ecSNathan Chancellor	# compressed debug sections to x86_x32 properly:
3152aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/514
3153aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/1141
3154aaeed6ecSNathan Chancellor	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3155a7f7f624SMasahiro Yamada	help
31565fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
31575fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
31585fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
31595fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
31605fd92e65SH. J. Lu
3161953fee1dSIngo Molnarconfig COMPAT_32
3162953fee1dSIngo Molnar	def_bool y
3163953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
3164953fee1dSIngo Molnar	select HAVE_UID16
3165953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
3166953fee1dSIngo Molnar
3167e279b6c1SSam Ravnborgconfig COMPAT
31683c2362e6SHarvey Harrison	def_bool y
316983a44a4fSMasahiro Yamada	depends on IA32_EMULATION || X86_X32_ABI
3170e279b6c1SSam Ravnborg
3171e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
31723120e25eSJan Beulich	def_bool y
3173a9251280SLinus Torvalds	depends on COMPAT
3174ee009e4aSDavid Howells
3175e279b6c1SSam Ravnborgendmenu
3176e279b6c1SSam Ravnborg
3177e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
3178e5beae16SKeith Packard	def_bool y
3179e5beae16SKeith Packard	depends on X86_32
3180e5beae16SKeith Packard
3181edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
31825e8ebd84SJason A. Donenfeld
31835e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
3184