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 7955d1ecceSEric Biggers select ARCH_HAS_CRC32 80ed4bc981SEric Biggers select ARCH_HAS_CRC_T10DIF if X86_64 812792d84eSKees Cook select ARCH_HAS_CURRENT_STACK_POINTER 82fa5b6ec9SLaura Abbott select ARCH_HAS_DEBUG_VIRTUAL 83399145f9SAnshuman Khandual select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 8421266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 85de6c85bfSChristoph Hellwig select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN 86b1a57bbfSDouglas Anderson select ARCH_HAS_EARLY_DEBUG if KGDB 876471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 8864f6a4e1SMike Rapoport (Microsoft) select ARCH_HAS_EXECMEM_ROX if X86_64 8972d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 906974f0c4SDaniel Micay select ARCH_HAS_FORTIFY_SOURCE 91957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 92bece04b5SMarco Elver select ARCH_HAS_KCOV if X86_64 93b0b8a15bSSamuel Holland select ARCH_HAS_KERNEL_FPU_SUPPORT 940c9c1d56SThiago Jung Bauermann select ARCH_HAS_MEM_ENCRYPT 9510bcc80eSMathieu Desnoyers select ARCH_HAS_MEMBARRIER_SYNC_CORE 9649f88c70SPaul E. McKenney select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 970ebeea8cSDaniel Borkmann select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 98c763ea26SIngo Molnar select ARCH_HAS_PMEM_API if X86_64 99476e8583SPeter Zijlstra select ARCH_HAS_PREEMPT_LAZY 10017596731SRobin Murphy select ARCH_HAS_PTE_DEVMAP if X86_64 1013010a5eaSLaurent Dufour select ARCH_HAS_PTE_SPECIAL 10271ce1ab5SKinsey Ho select ARCH_HAS_HW_PTE_YOUNG 103eed9a328SYu Zhao select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2 1040aed55afSDan Williams select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 105ec6347bbSDan Williams select ARCH_HAS_COPY_MC if X86_64 106d2852a22SDaniel Borkmann select ARCH_HAS_SET_MEMORY 107d253ca0cSRick Edgecombe select ARCH_HAS_SET_DIRECT_MAP 108ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_KERNEL_RWX 109ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_MODULE_RWX 110ac1ab12aSMathieu Desnoyers select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 11125c619e5SBrian Gerst select ARCH_HAS_SYSCALL_WRAPPER 112918327e9SKees Cook select ARCH_HAS_UBSAN 1137e01ccb4SZong Li select ARCH_HAS_DEBUG_WX 11463703f37SKefeng Wang select ARCH_HAS_ZONE_DMA_SET if EXPERT 1156471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 116ba386777SVignesh Balasubramanian select ARCH_HAVE_EXTRA_ELF_NOTES 11704d5ea46SAneesh Kumar K.V select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 1186471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 11977fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 1205e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 1213599fe12SThomas Gleixner select ARCH_STACKWALK 1222c870e61SArnd Bergmann select ARCH_SUPPORTS_ACPI 1236471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 1245d6ad668SMike Rapoport select ARCH_SUPPORTS_DEBUG_PAGEALLOC 125d283d422SPasha Tatashin select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 1266471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 12714df3267SThomas Gleixner select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 1283c516f89SSami Tolvanen select ARCH_SUPPORTS_CFI_CLANG if X86_64 1293c516f89SSami Tolvanen select ARCH_USES_CFI_TRAPS if X86_64 && CFI_CLANG 130583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG 131583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG_THIN 132d2d6422fSSebastian Andrzej Siewior select ARCH_SUPPORTS_RT 133315ad878SRong Xu select ARCH_SUPPORTS_AUTOFDO_CLANG 134d5dc9583SRong Xu select ARCH_SUPPORTS_PROPELLER_CLANG if X86_64 1356471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 136a432b7c0SUros Bizjak select ARCH_USE_CMPXCHG_LOCKREF if X86_CMPXCHG64 137dce44566SAnshuman Khandual select ARCH_USE_MEMTEST 1386471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 1396471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 1402ce0d7f9SMark Brown select ARCH_USE_SYM_ANNOTATIONS 141ce4a4e56SAndy Lutomirski select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 14281c22041SDaniel Borkmann select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 143c763ea26SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 14451c2ee6dSNick Desaulniers select ARCH_WANTS_NO_INSTR 14507431506SAnshuman Khandual select ARCH_WANT_GENERAL_HUGETLB 1463876d4a3SAlexandre Ghiti select ARCH_WANT_HUGE_PMD_SHARE 14759612b24SNathan Chancellor select ARCH_WANT_LD_ORPHAN_WARN 1480b6f1582SAneesh Kumar K.V select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64 1490b6f1582SAneesh Kumar K.V select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64 15038d8b4e6SHuang Ying select ARCH_WANTS_THP_SWAP if X86_64 151b5f06f64SBalbir Singh select ARCH_HAS_PARANOID_L1D_FLUSH 15210916706SShile Zhang select BUILDTIME_TABLE_SORT 1536471b825SIngo Molnar select CLKEVT_I8253 1546471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 1557cf8f44aSAlexander Potapenko # Word-size accesses may read uninitialized data past the trailing \0 1567cf8f44aSAlexander Potapenko # in strings and cause false KMSAN reports. 1577cf8f44aSAlexander Potapenko select DCACHE_WORD_ACCESS if !KMSAN 1583aac3ebeSThomas Gleixner select DYNAMIC_SIGFRAME 15945471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 16045471cd9SLinus Torvalds select EDAC_SUPPORT 1616471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 162cb81deefSThomas Gleixner select GENERIC_CLOCKEVENTS_BROADCAST_IDLE if GENERIC_CLOCKEVENTS_BROADCAST 1636471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 1646471b825SIngo Molnar select GENERIC_CMOS_UPDATE 1656471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 1665b95f94cSJames Morse select GENERIC_CPU_DEVICES 16761dc0f55SThomas Gleixner select GENERIC_CPU_VULNERABILITIES 1686471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 16927d6b4d1SThomas Gleixner select GENERIC_ENTRY 1706471b825SIngo Molnar select GENERIC_IOMAP 171c7d6c9ddSThomas Gleixner select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 1720fa115daSThomas Gleixner select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 173ad7a929fSThomas Gleixner select GENERIC_IRQ_MIGRATION if SMP 1746471b825SIngo Molnar select GENERIC_IRQ_PROBE 175c201c917SThomas Gleixner select GENERIC_IRQ_RESERVATION_MODE 1766471b825SIngo Molnar select GENERIC_IRQ_SHOW 1776471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 1782ae27137SSteven Price select GENERIC_PTDUMP 1796471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 1806471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 1817ac87074SVincenzo Frascino select GENERIC_GETTIMEOFDAY 182550a77a7SDmitry Safonov select GENERIC_VDSO_TIME_NS 1837e90ffb7SAdrian Hunter select GENERIC_VDSO_OVERFLOW_PROTECT 1846ca297d4SPeter Zijlstra select GUP_GET_PXX_LOW_HIGH if X86_PAE 18517e5888eSHans de Goede select HARDIRQS_SW_RESEND 1867edaeb68SThomas Gleixner select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 187fcbfe812SNiklas Schnelle select HAS_IOPORT 1886471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 1896471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 1902a19be61SVlastimil Babka select HAVE_ALIGNED_STRUCT_PAGE 1916471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 1926471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 193eed1fceeSSong Liu select HAVE_ARCH_HUGE_VMALLOC if X86_64 1946471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 195b34006c4SArd Biesheuvel select HAVE_ARCH_JUMP_LABEL_RELATIVE 196d17a1d97SAndrey Ryabinin select HAVE_ARCH_KASAN if X86_64 1970609ae01SDaniel Axtens select HAVE_ARCH_KASAN_VMALLOC if X86_64 1981dc0da6eSAlexander Potapenko select HAVE_ARCH_KFENCE 1994ca8cc8dSAlexander Potapenko select HAVE_ARCH_KMSAN if X86_64 2006471b825SIngo Molnar select HAVE_ARCH_KGDB 2019e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 2029e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 2031b028f78SDmitry Safonov select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 204271ca788SArd Biesheuvel select HAVE_ARCH_PREL32_RELOCATIONS 2056471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 206f7d83c1cSKees Cook select HAVE_ARCH_THREAD_STRUCT_WHITELIST 207afaef01cSAlexander Popov select HAVE_ARCH_STACKLEAK 2086471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 2096471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 210a00cc7d9SMatthew Wilcox select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 211b64d8d1eSPeter Xu select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 2127677f7fdSAxel Rasmussen select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD 213e37e43a4SAndy Lutomirski select HAVE_ARCH_VMAP_STACK if X86_64 214fe950f60SKees Cook select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 215c763ea26SIngo Molnar select HAVE_ARCH_WITHIN_STACK_FRAMES 2162ff2b7ecSMasahiro Yamada select HAVE_ASM_MODVERSIONS 2176471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 2186471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 21924a9c541SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_USER if X86_64 22024a9c541SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER 2216471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 22203f16cd0SJosh Poimboeuf select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL 223280981d6SSathvika Vasireddy select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT 2244ed308c4SSteven Rostedt (Google) select HAVE_BUILDTIME_MCOUNT_SORT 2256471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 2269c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 227677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 22806aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 22902a474caSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 230762abbc0SMasami Hiramatsu (Google) select HAVE_FTRACE_REGS_HAVING_PT_REGS if X86_64 231562955feSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 232c316eb44SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 233503e4510SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 23403f5781bSWang YanQing select HAVE_EBPF_JIT 23558340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 2366630a8e5SChristoph Hellwig select HAVE_EISA 2375f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 23825176ad0SDavid Hildenbrand select HAVE_GUP_FAST 239644e0e8dSSteven Rostedt (VMware) select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 240a762e926SMasami Hiramatsu (Google) select HAVE_FTRACE_GRAPH_FUNC if HAVE_FUNCTION_GRAPH_TRACER 2416471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 242a3ed4157SMasami Hiramatsu (Google) select HAVE_FUNCTION_GRAPH_FREGS if HAVE_FUNCTION_GRAPH_TRACER 2434a30e4c9SSteven Rostedt (VMware) select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) 2446471b825SIngo Molnar select HAVE_FUNCTION_TRACER 2456b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 2460067f129SK.Prasad select HAVE_HW_BREAKPOINT 2476471b825SIngo Molnar select HAVE_IOREMAP_PROT 248624db9eaSThomas Gleixner select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 2496471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 2504ab7674fSJosh Poimboeuf select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL 2516471b825SIngo Molnar select HAVE_KERNEL_BZIP2 2526471b825SIngo Molnar select HAVE_KERNEL_GZIP 2536471b825SIngo Molnar select HAVE_KERNEL_LZ4 2546471b825SIngo Molnar select HAVE_KERNEL_LZMA 2556471b825SIngo Molnar select HAVE_KERNEL_LZO 2566471b825SIngo Molnar select HAVE_KERNEL_XZ 257fb46d057SNick Terrell select HAVE_KERNEL_ZSTD 2586471b825SIngo Molnar select HAVE_KPROBES 2596471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 260540adea3SMasami Hiramatsu select HAVE_FUNCTION_ERROR_INJECTION 2616471b825SIngo Molnar select HAVE_KRETPROBES 262f3a112c0SMasami Hiramatsu select HAVE_RETHOOK 2636471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 2640102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 265ee9f8fceSJosh Poimboeuf select HAVE_MOD_ARCH_SPECIFIC 2669f132f7eSJoel Fernandes (Google) select HAVE_MOVE_PMD 267be37c98dSKalesh Singh select HAVE_MOVE_PUD 26822102f45SJosh Poimboeuf select HAVE_NOINSTR_HACK if HAVE_OBJTOOL 26942a0bb3fSPetr Mladek select HAVE_NMI 270489e355bSJosh Poimboeuf select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL 27103f16cd0SJosh Poimboeuf select HAVE_OBJTOOL if X86_64 2726471b825SIngo Molnar select HAVE_OPTPROBES 2735394f1e9SArnd Bergmann select HAVE_PAGE_SIZE_4KB 2746471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 2756471b825SIngo Molnar select HAVE_PERF_EVENTS 276c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 27792e5aae4SNicholas Piggin select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 278eb01d42aSChristoph Hellwig select HAVE_PCI 279c5e63197SJiri Olsa select HAVE_PERF_REGS 280c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 281a3725973SRik van Riel select MMU_GATHER_RCU_TABLE_FREE 2821e9fdf21SPeter Zijlstra select MMU_GATHER_MERGE_VMAS 28300998085SThomas Gleixner select HAVE_POSIX_CPU_TIMERS_TASK_WORK 2846471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 28503f16cd0SJosh Poimboeuf select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION 2863c88ee19SMasami Hiramatsu select HAVE_FUNCTION_ARG_ACCESS_API 2877ecd19cfSKefeng Wang select HAVE_SETUP_PER_CPU_AREA 288cd1a41ceSThomas Gleixner select HAVE_SOFTIRQ_ON_OWN_STACK 289d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 29003f16cd0SJosh Poimboeuf select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 291e6d6c071SJosh Poimboeuf select HAVE_STATIC_CALL 29203f16cd0SJosh Poimboeuf select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL 29399cf983cSMark Rutland select HAVE_PREEMPT_DYNAMIC_CALL 294d6761b8fSMathieu Desnoyers select HAVE_RSEQ 29509498135SMiguel Ojeda select HAVE_RUST if X86_64 2966471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 2975f3da8c0SJosh Poimboeuf select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL 2986471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 2997c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 3007ac87074SVincenzo Frascino select HAVE_GENERIC_VDSO 30133385150SJason A. Donenfeld select VDSO_GETRANDOM if X86_64 3020c7ffa32SThomas Gleixner select HOTPLUG_PARALLEL if SMP && X86_64 30305736e4aSThomas Gleixner select HOTPLUG_SMT if SMP 3040c7ffa32SThomas Gleixner select HOTPLUG_SPLIT_STARTUP if SMP && X86_32 305c0185808SThomas Gleixner select IRQ_FORCED_THREADING 306c2508ec5SLinus Torvalds select LOCK_MM_AND_FIND_VMA 3077ecd19cfSKefeng Wang select NEED_PER_CPU_EMBED_FIRST_CHUNK 3087ecd19cfSKefeng Wang select NEED_PER_CPU_PAGE_FIRST_CHUNK 30986596f0aSChristoph Hellwig select NEED_SG_DMA_LENGTH 31087482708SMike Rapoport (Microsoft) select NUMA_MEMBLKS if NUMA 3112eac9c2dSChristoph Hellwig select PCI_DOMAINS if PCI 312625210cfSSinan Kaya select PCI_LOCKLESS_CONFIG if PCI 3136471b825SIngo Molnar select PERF_EVENTS 3143195ef59SPrarit Bhargava select RTC_LIB 315d6faca40SArnd Bergmann select RTC_MC146818_LIB 3166471b825SIngo Molnar select SPARSE_IRQ 3176471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 31815f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 3194aae683fSMasahiro Yamada select TRACE_IRQFLAGS_SUPPORT 3204510bffbSMark Rutland select TRACE_IRQFLAGS_NMI_SUPPORT 3216471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 3223b02a051SIngo Molnar select HAVE_ARCH_KCSAN if X86_64 3230c608dadSAubrey Li select PROC_PID_ARCH_STATUS if PROC_FS 32450468e43SJarkko Sakkinen select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX 325d49a0626SPeter Zijlstra select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16 326d49a0626SPeter Zijlstra select FUNCTION_ALIGNMENT_4B 3279e2b4be3SNayna Jain imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 328ceea991aSJiri Olsa select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 3294817f70cSQi Zheng select ARCH_SUPPORTS_PT_RECLAIM if X86_64 3307d8330a5SBalbir Singh 331ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 3323120e25eSJan Beulich def_bool y 3333120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 334ba7e4d13SIngo Molnar 33551b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 33651b26adaSLinus Torvalds string 33751b26adaSLinus Torvalds default "elf32-i386" if X86_32 33851b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 33951b26adaSLinus Torvalds 3408d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 3413c2362e6SHarvey Harrison def_bool y 3428d5fffb9SSam Ravnborg 3438d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 3443c2362e6SHarvey Harrison def_bool y 3458d5fffb9SSam Ravnborg 3468d5fffb9SSam Ravnborgconfig MMU 3473c2362e6SHarvey Harrison def_bool y 3488d5fffb9SSam Ravnborg 3499e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 3509e08f57dSDaniel Cashman default 28 if 64BIT 3519e08f57dSDaniel Cashman default 8 3529e08f57dSDaniel Cashman 3539e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 3549e08f57dSDaniel Cashman default 32 if 64BIT 3559e08f57dSDaniel Cashman default 16 3569e08f57dSDaniel Cashman 3579e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 3589e08f57dSDaniel Cashman default 8 3599e08f57dSDaniel Cashman 3609e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 3619e08f57dSDaniel Cashman default 16 3629e08f57dSDaniel Cashman 3638d5fffb9SSam Ravnborgconfig SBUS 3648d5fffb9SSam Ravnborg bool 3658d5fffb9SSam Ravnborg 3668d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 3673120e25eSJan Beulich def_bool y 3683120e25eSJan Beulich depends on ISA_DMA_API 3698d5fffb9SSam Ravnborg 370d911c67eSAlexander Potapenkoconfig GENERIC_CSUM 371d911c67eSAlexander Potapenko bool 372d911c67eSAlexander Potapenko default y if KMSAN || KASAN 373d911c67eSAlexander Potapenko 3748d5fffb9SSam Ravnborgconfig GENERIC_BUG 3753c2362e6SHarvey Harrison def_bool y 3768d5fffb9SSam Ravnborg depends on BUG 377b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 378b93a531eSJan Beulich 379b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 380b93a531eSJan Beulich bool 3818d5fffb9SSam Ravnborg 3828d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 3833120e25eSJan Beulich def_bool y 3843120e25eSJan Beulich depends on ISA_DMA_API 3858d5fffb9SSam Ravnborg 3861032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 3871032c0baSSam Ravnborg def_bool y 3881032c0baSSam Ravnborg 3899a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 3909a0b8415Svenkatesh.pallipadi@intel.com def_bool y 3918d5fffb9SSam Ravnborg 392801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 393801e4062SJohannes Berg def_bool y 394801e4062SJohannes Berg 395f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 396f4cb5700SJohannes Berg def_bool y 397f4cb5700SJohannes Berg 3988d5fffb9SSam Ravnborgconfig AUDIT_ARCH 399e0fd24a3SJan Beulich def_bool y if X86_64 4008d5fffb9SSam Ravnborg 401d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 402d6f2d75aSAndrey Ryabinin hex 403d6f2d75aSAndrey Ryabinin depends on KASAN 404d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 405d6f2d75aSAndrey Ryabinin 40669575d38SShane Wangconfig HAVE_INTEL_TXT 40769575d38SShane Wang def_bool y 4086ea30386SKees Cook depends on INTEL_IOMMU && ACPI 40969575d38SShane Wang 4106b0c3d44SSam Ravnborgconfig X86_64_SMP 4116b0c3d44SSam Ravnborg def_bool y 4126b0c3d44SSam Ravnborg depends on X86_64 && SMP 4136b0c3d44SSam Ravnborg 4142b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 4152b144498SSrikar Dronamraju def_bool y 4162b144498SSrikar Dronamraju 417d20642f0SRob Herringconfig FIX_EARLYCON_MEM 418d20642f0SRob Herring def_bool y 419d20642f0SRob Herring 42094d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK 42194d49eb3SKirill A. Shutemov bool 42294d49eb3SKirill A. Shutemov 42398233368SKirill A. Shutemovconfig PGTABLE_LEVELS 42498233368SKirill A. Shutemov int 42577ef56e4SKirill A. Shutemov default 5 if X86_5LEVEL 42698233368SKirill A. Shutemov default 4 if X86_64 42798233368SKirill A. Shutemov default 3 if X86_PAE 42898233368SKirill A. Shutemov default 2 42998233368SKirill A. Shutemov 4302a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR 4312a61f474SMasahiro Yamada bool 4321b866781SNathan Chancellor default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT 4331b866781SNathan Chancellor default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) 4342a61f474SMasahiro Yamada help 4352a61f474SMasahiro Yamada We have to make sure stack protector is unconditionally disabled if 4363fb0fdb3SAndy Lutomirski the compiler produces broken code or if it does not let us control 4373fb0fdb3SAndy Lutomirski the segment on 32-bit kernels. 4382a61f474SMasahiro Yamada 439506f1d07SSam Ravnborgmenu "Processor type and features" 440506f1d07SSam Ravnborg 441506f1d07SSam Ravnborgconfig SMP 442506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 443a7f7f624SMasahiro Yamada help 444506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 4454a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 4464a474157SRobert Graffham than one CPU, say Y. 447506f1d07SSam Ravnborg 4484a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 449506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 450506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 4514a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 452506f1d07SSam Ravnborg will run faster if you say N here. 453506f1d07SSam Ravnborg 454506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 455506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 456506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 457506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 458506f1d07SSam Ravnborg 459506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 460506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 461506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 462506f1d07SSam Ravnborg 463ff61f079SJonathan Corbet See also <file:Documentation/arch/x86/i386/IO-APIC.rst>, 4644f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 465506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 466506f1d07SSam Ravnborg 467506f1d07SSam Ravnborg If you don't know what to do here, say N. 468506f1d07SSam Ravnborg 46906cd9a7dSYinghai Luconfig X86_X2APIC 47006cd9a7dSYinghai Lu bool "Support x2apic" 47119e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 472a7f7f624SMasahiro Yamada help 47306cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 47406cd9a7dSYinghai Lu 47506cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 47606cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 47706cd9a7dSYinghai Lu 478b8d1d163SDaniel Sneddon Some Intel systems circa 2022 and later are locked into x2APIC mode 479b8d1d163SDaniel Sneddon and can not fall back to the legacy APIC modes if SGX or TDX are 480e3998434SMateusz Jończyk enabled in the BIOS. They will boot with very reduced functionality 481e3998434SMateusz Jończyk without enabling this option. 482b8d1d163SDaniel Sneddon 48306cd9a7dSYinghai Lu If you don't know what to do here, say N. 48406cd9a7dSYinghai Lu 4857fec07fdSJacob Panconfig X86_POSTED_MSI 4867fec07fdSJacob Pan bool "Enable MSI and MSI-x delivery by posted interrupts" 4877fec07fdSJacob Pan depends on X86_64 && IRQ_REMAP 4887fec07fdSJacob Pan help 4897fec07fdSJacob Pan This enables MSIs that are under interrupt remapping to be delivered as 4907fec07fdSJacob Pan posted interrupts to the host kernel. Interrupt throughput can 4917fec07fdSJacob Pan potentially be improved by coalescing CPU notifications during high 4927fec07fdSJacob Pan frequency bursts. 4937fec07fdSJacob Pan 4947fec07fdSJacob Pan If you don't know what to do here, say N. 4957fec07fdSJacob Pan 4966695c85bSYinghai Luconfig X86_MPPARSE 4974590d98fSAndy Shevchenko bool "Enable MPS table" if ACPI 4987a527688SJan Beulich default y 4995ab74722SIngo Molnar depends on X86_LOCAL_APIC 500a7f7f624SMasahiro Yamada help 5016695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 5026695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 5036695c85bSYinghai Lu 504e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 505e6d42931SJohannes Weiner bool "x86 CPU resource control support" 5066fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 50759fe5a77SThomas Gleixner select KERNFS 508e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 50978e99b4aSFenghua Yu help 510e6d42931SJohannes Weiner Enable x86 CPU resource control support. 5116fe07ce3SBabu Moger 5126fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 5136fe07ce3SBabu Moger usage by the CPU. 5146fe07ce3SBabu Moger 5156fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 5166fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 5176fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 5186fe07ce3SBabu Moger 5196fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 5206fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 5216fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 52278e99b4aSFenghua Yu 52378e99b4aSFenghua Yu Say N if unsure. 52478e99b4aSFenghua Yu 5252cce9591SH. Peter Anvin (Intel)config X86_FRED 5262cce9591SH. Peter Anvin (Intel) bool "Flexible Return and Event Delivery" 5272cce9591SH. Peter Anvin (Intel) depends on X86_64 5282cce9591SH. Peter Anvin (Intel) help 5292cce9591SH. Peter Anvin (Intel) When enabled, try to use Flexible Return and Event Delivery 5302cce9591SH. Peter Anvin (Intel) instead of the legacy SYSCALL/SYSENTER/IDT architecture for 5312cce9591SH. Peter Anvin (Intel) ring transitions and exception/interrupt handling if the 5323c41786cSPaul Menzel system supports it. 5332cce9591SH. Peter Anvin (Intel) 534c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 535c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 536c5c606d9SRavikiran G Thirumalai default y 537a7f7f624SMasahiro Yamada help 53806ac8346SIngo Molnar If you disable this option then the kernel will only support 53906ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 54006ac8346SIngo Molnar systems out there.) 54106ac8346SIngo Molnar 5428425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 54371d99ea4SMasahiro Yamada for the following non-PC x86 platforms, depending on the value of 54471d99ea4SMasahiro Yamada CONFIG_64BIT. 54571d99ea4SMasahiro Yamada 54671d99ea4SMasahiro Yamada 32-bit platforms (CONFIG_64BIT=n): 547cb7b8023SBen Hutchings Goldfish (Android emulator) 5488425091fSRavikiran G Thirumalai AMD Elan 5498425091fSRavikiran G Thirumalai RDC R-321x SoC 5508425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 55183125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 55206ac8346SIngo Molnar 55371d99ea4SMasahiro Yamada 64-bit platforms (CONFIG_64BIT=y): 55444b111b5SSteffen Persvold Numascale NumaChip 5558425091fSRavikiran G Thirumalai ScaleMP vSMP 5568425091fSRavikiran G Thirumalai SGI Ultraviolet 557*ca5955ddSArnd Bergmann Merrifield/Moorefield MID devices 5588425091fSRavikiran G Thirumalai 5598425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5608425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 56171d99ea4SMasahiro Yamada 562c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 563c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 56444b111b5SSteffen Persvoldconfig X86_NUMACHIP 56544b111b5SSteffen Persvold bool "Numascale NumaChip" 56644b111b5SSteffen Persvold depends on X86_64 56744b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 56844b111b5SSteffen Persvold depends on NUMA 56944b111b5SSteffen Persvold depends on SMP 57044b111b5SSteffen Persvold depends on X86_X2APIC 571f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 572a7f7f624SMasahiro Yamada help 57344b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 57444b111b5SSteffen Persvold enable more than ~168 cores. 57544b111b5SSteffen Persvold If you don't have one of these, you should say N here. 57603b48632SNick Piggin 5776a48565eSIngo Molnarconfig X86_VSMP 578c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5796276a074SBorislav Petkov select HYPERVISOR_GUEST 5806a48565eSIngo Molnar select PARAVIRT 5816a48565eSIngo Molnar depends on X86_64 && PCI 582c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 583ead91d4bSShai Fultheim depends on SMP 584a7f7f624SMasahiro Yamada help 5856a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5866a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5876a48565eSIngo Molnar if you have one of these machines. 5886a48565eSIngo Molnar 589c5c606d9SRavikiran G Thirumalaiconfig X86_UV 590c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 591c5c606d9SRavikiran G Thirumalai depends on X86_64 592c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 59354c28d29SJack Steiner depends on NUMA 5941ecb4ae5SAndrew Morton depends on EFI 595c2209ea5SIngo Molnar depends on KEXEC_CORE 5969d6c26e7SSuresh Siddha depends on X86_X2APIC 5971222e564SIngo Molnar depends on PCI 598a7f7f624SMasahiro Yamada help 599c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 600c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 601c5c606d9SRavikiran G Thirumalai 602*ca5955ddSArnd Bergmannconfig X86_INTEL_MID 603*ca5955ddSArnd Bergmann bool "Intel Z34xx/Z35xx MID platform support" 604*ca5955ddSArnd Bergmann depends on X86_EXTENDED_PLATFORM 605*ca5955ddSArnd Bergmann depends on X86_PLATFORM_DEVICES 606*ca5955ddSArnd Bergmann depends on PCI 607*ca5955ddSArnd Bergmann depends on X86_64 || (EXPERT && PCI_GOANY) 608*ca5955ddSArnd Bergmann depends on X86_IO_APIC 609*ca5955ddSArnd Bergmann select I2C 610*ca5955ddSArnd Bergmann select DW_APB_TIMER 611*ca5955ddSArnd Bergmann select INTEL_SCU_PCI 612*ca5955ddSArnd Bergmann help 613*ca5955ddSArnd Bergmann Select to build a kernel capable of supporting 64-bit Intel MID 614*ca5955ddSArnd Bergmann (Mobile Internet Device) platform systems which do not have 615*ca5955ddSArnd Bergmann the PCI legacy interfaces. 616*ca5955ddSArnd Bergmann 617*ca5955ddSArnd Bergmann The only supported devices are the 22nm Merrified (Z34xx) 618*ca5955ddSArnd Bergmann and Moorefield (Z35xx) SoC used in the Intel Edison board and 619*ca5955ddSArnd Bergmann a small number of Android devices such as the Asus Zenfone 2, 620*ca5955ddSArnd Bergmann Asus FonePad 8 and Dell Venue 7. 621*ca5955ddSArnd Bergmann 622*ca5955ddSArnd Bergmann If you are building for a PC class system or non-MID tablet 623*ca5955ddSArnd Bergmann SoCs like Bay Trail (Z36xx/Z37xx), say N here. 624*ca5955ddSArnd Bergmann 625*ca5955ddSArnd Bergmann Intel MID platforms are based on an Intel processor and chipset which 626*ca5955ddSArnd Bergmann consume less power than most of the x86 derivatives. 627506f1d07SSam Ravnborg 628ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 629ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 630cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 631a7f7f624SMasahiro Yamada help 632ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 633ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 634ddd70cf9SJun Nakajima Goldfish emulator say N here. 635ddd70cf9SJun Nakajima 636*ca5955ddSArnd Bergmann# Following is an alphabetically sorted list of 32 bit extended platforms 637*ca5955ddSArnd Bergmann# Please maintain the alphabetic order if and when there are additions 638*ca5955ddSArnd Bergmann 639c751e17bSThomas Gleixnerconfig X86_INTEL_CE 640c751e17bSThomas Gleixner bool "CE4100 TV platform" 641c751e17bSThomas Gleixner depends on PCI 642c751e17bSThomas Gleixner depends on PCI_GODIRECT 6436084a6e2SJiang Liu depends on X86_IO_APIC 644c751e17bSThomas Gleixner depends on X86_32 645c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 64637bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 647da6b737bSSebastian Andrzej Siewior select OF 648da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 649a7f7f624SMasahiro Yamada help 650c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 651c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 652c751e17bSThomas Gleixner boxes and media devices. 653c751e17bSThomas Gleixner 6548bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6558bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6568bbc2a13SBryan O'Donoghue depends on X86_32 6578bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6588bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6598bbc2a13SBryan O'Donoghue depends on X86_TSC 6608bbc2a13SBryan O'Donoghue depends on PCI 6618bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6628bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6638bbc2a13SBryan O'Donoghue select IOSF_MBI 6648bbc2a13SBryan O'Donoghue select INTEL_IMR 6659ab6eb51SAndy Shevchenko select COMMON_CLK 666a7f7f624SMasahiro Yamada help 6678bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6688bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6698bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6708bbc2a13SBryan O'Donoghue 6713d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6723d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6735962dd22SSinan Kaya depends on X86 && ACPI && PCI 6743d48aab1SMika Westerberg select COMMON_CLK 6750f531431SMathias Nyman select PINCTRL 676eebb3e8dSAndy Shevchenko select IOSF_MBI 677a7f7f624SMasahiro Yamada help 6783d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6793d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6800f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6810f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6823d48aab1SMika Westerberg 68392082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 68492082a88SKen Xue bool "AMD ACPI2Platform devices support" 68592082a88SKen Xue depends on ACPI 68692082a88SKen Xue select COMMON_CLK 68792082a88SKen Xue select PINCTRL 688a7f7f624SMasahiro Yamada help 68992082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 69092082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 69192082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 69292082a88SKen Xue implemented under PINCTRL subsystem. 69392082a88SKen Xue 694ced3ce76SDavid E. Boxconfig IOSF_MBI 695ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 696ced3ce76SDavid E. Box depends on PCI 697a7f7f624SMasahiro Yamada help 698ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 699ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 700ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 701ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 702ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 703ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 704ced3ce76SDavid E. Box This list is not meant to be exclusive. 705ced3ce76SDavid E. Box - BayTrail 706ced3ce76SDavid E. Box - Braswell 707ced3ce76SDavid E. Box - Quark 708ced3ce76SDavid E. Box 709ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 710ced3ce76SDavid E. Box 711ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 712ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 713ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 714a7f7f624SMasahiro Yamada help 715ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 716ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 717ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 718ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 719ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 720ed2226bdSDavid E. Box device they want to access. 721ed2226bdSDavid E. Box 722ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 723ed2226bdSDavid E. Box 724c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 725c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 726506f1d07SSam Ravnborg depends on X86_32 727c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 728c5c606d9SRavikiran G Thirumalai select M486 729c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 730a7f7f624SMasahiro Yamada help 731c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 732c5c606d9SRavikiran G Thirumalai as R-8610-(G). 733c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 734c5c606d9SRavikiran G Thirumalai 735e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7369c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7379c398017SIngo Molnar depends on X86_32 && SMP 738c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 739a7f7f624SMasahiro Yamada help 7400abf5086SArnd Bergmann This option compiles in the STA2X11 default 7410abf5086SArnd Bergmann subarchitecture. It is intended for a generic binary 742b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 743b5660ba7SH. Peter Anvin one and will fallback to default. 744d49c4288SYinghai Lu 745c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 746d49c4288SYinghai Lu 747d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7486fc108a0SJan Beulich def_bool y 749d949f36fSLinus Torvalds # MCE code calls memory_failure(): 750d949f36fSLinus Torvalds depends on X86_MCE 751d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 752d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 753d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 754d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 755d949f36fSLinus Torvalds 75683125a3aSAlessandro Rubiniconfig STA2X11 75783125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 75883125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 75983125a3aSAlessandro Rubini select SWIOTLB 76083125a3aSAlessandro Rubini select MFD_STA2X11 7610145071bSLinus Walleij select GPIOLIB 762a7f7f624SMasahiro Yamada help 76383125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 76483125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 76583125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 76683125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 76783125a3aSAlessandro Rubini standard PC machines. 76883125a3aSAlessandro Rubini 76982148d1dSShérabconfig X86_32_IRIS 77082148d1dSShérab tristate "Eurobraille/Iris poweroff module" 77182148d1dSShérab depends on X86_32 772a7f7f624SMasahiro Yamada help 77382148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 77482148d1dSShérab to shut themselves down properly. A special I/O sequence is 77582148d1dSShérab needed to do so, which is what this module does at 77682148d1dSShérab kernel shutdown. 77782148d1dSShérab 77882148d1dSShérab This is only for Iris machines from EuroBraille. 77982148d1dSShérab 78082148d1dSShérab If unused, say N. 78182148d1dSShérab 782ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7833c2362e6SHarvey Harrison def_bool y 7843c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 785a87d0914SKen Chen depends on X86 786a7f7f624SMasahiro Yamada help 787506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 788506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 789506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 790506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 791506f1d07SSam Ravnborg 792506f1d07SSam Ravnborg If in doubt, say "Y". 793506f1d07SSam Ravnborg 7946276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7956276a074SBorislav Petkov bool "Linux guest support" 796a7f7f624SMasahiro Yamada help 7976276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7986276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7996276a074SBorislav Petkov setup. 800506f1d07SSam Ravnborg 8016276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 8026276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 803506f1d07SSam Ravnborg 8046276a074SBorislav Petkovif HYPERVISOR_GUEST 805506f1d07SSam Ravnborg 806e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 807e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 808a0e2bf7cSJuergen Gross depends on HAVE_STATIC_CALL 809a7f7f624SMasahiro Yamada help 810e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 811e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 812e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 813e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 814e61bd94aSEduardo Pereira Habkost 815c00a280aSJuergen Grossconfig PARAVIRT_XXL 816c00a280aSJuergen Gross bool 817c00a280aSJuergen Gross 8186276a074SBorislav Petkovconfig PARAVIRT_DEBUG 8196276a074SBorislav Petkov bool "paravirt-ops debugging" 8206276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 821a7f7f624SMasahiro Yamada help 8226276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 8236276a074SBorislav Petkov a paravirt_op is missing when it is called. 8246276a074SBorislav Petkov 825b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 826b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 8276ea30386SKees Cook depends on PARAVIRT && SMP 828a7f7f624SMasahiro Yamada help 829b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 830b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 831b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 832b4ecc126SJeremy Fitzhardinge 8334c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 8344c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 835b4ecc126SJeremy Fitzhardinge 8364c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 837b4ecc126SJeremy Fitzhardinge 838ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 839ecca2502SZhao Yakui def_bool n 840ecca2502SZhao Yakui 8416276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8426276a074SBorislav Petkov 8436276a074SBorislav Petkovconfig KVM_GUEST 8446276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8456276a074SBorislav Petkov depends on PARAVIRT 8466276a074SBorislav Petkov select PARAVIRT_CLOCK 847a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 848b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8496276a074SBorislav Petkov default y 850a7f7f624SMasahiro Yamada help 8516276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8526276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8536276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8546276a074SBorislav Petkov underlying device model, the host provides the guest with 8556276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8566276a074SBorislav Petkov 857a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 858a1c4423bSMarcelo Tosatti def_bool n 859a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 860a1c4423bSMarcelo Tosatti help 861a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 862a1c4423bSMarcelo Tosatti 8637733607fSMaran Wilsonconfig PVH 8647733607fSMaran Wilson bool "Support for running PVH guests" 865a7f7f624SMasahiro Yamada help 8667733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8677733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8687733607fSMaran Wilson 8696276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8706276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8716276a074SBorislav Petkov depends on PARAVIRT 872a7f7f624SMasahiro Yamada help 8736276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8746276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8756276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8766276a074SBorislav Petkov that, there can be a small performance impact. 8776276a074SBorislav Petkov 8786276a074SBorislav Petkov If in doubt, say N here. 8796276a074SBorislav Petkov 8807af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8817af192c9SGerd Hoffmann bool 8827af192c9SGerd Hoffmann 8834a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8844a362601SJan Kiszka bool "Jailhouse non-root cell support" 885abde587bSArnd Bergmann depends on X86_64 && PCI 88687e65d05SJan Kiszka select X86_PM_TIMER 887a7f7f624SMasahiro Yamada help 8884a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8894a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8904a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8914a362601SJan Kiszka 892ec7972c9SZhao Yakuiconfig ACRN_GUEST 893ec7972c9SZhao Yakui bool "ACRN Guest support" 894ec7972c9SZhao Yakui depends on X86_64 895498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 896ec7972c9SZhao Yakui help 897ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 898ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 899ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 900ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 901ec7972c9SZhao Yakui found in https://projectacrn.org/. 902ec7972c9SZhao Yakui 90359bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST 90459bd54a8SKuppuswamy Sathyanarayanan bool "Intel TDX (Trust Domain Extensions) - Guest Support" 90559bd54a8SKuppuswamy Sathyanarayanan depends on X86_64 && CPU_SUP_INTEL 90659bd54a8SKuppuswamy Sathyanarayanan depends on X86_X2APIC 90775d090fdSKirill A. Shutemov depends on EFI_STUB 90841394e33SKirill A. Shutemov select ARCH_HAS_CC_PLATFORM 909968b4931SKirill A. Shutemov select X86_MEM_ENCRYPT 91077a512e3SSean Christopherson select X86_MCE 91175d090fdSKirill A. Shutemov select UNACCEPTED_MEMORY 91259bd54a8SKuppuswamy Sathyanarayanan help 91359bd54a8SKuppuswamy Sathyanarayanan Support running as a guest under Intel TDX. Without this support, 91459bd54a8SKuppuswamy Sathyanarayanan the guest kernel can not boot or run under TDX. 91559bd54a8SKuppuswamy Sathyanarayanan TDX includes memory encryption and integrity capabilities 91659bd54a8SKuppuswamy Sathyanarayanan which protect the confidentiality and integrity of guest 91759bd54a8SKuppuswamy Sathyanarayanan memory contents and CPU state. TDX guests are protected from 91859bd54a8SKuppuswamy Sathyanarayanan some attacks from the VMM. 91959bd54a8SKuppuswamy Sathyanarayanan 9206276a074SBorislav Petkovendif # HYPERVISOR_GUEST 92197349135SJeremy Fitzhardinge 922506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 923506f1d07SSam Ravnborg 924506f1d07SSam Ravnborgconfig HPET_TIMER 9253c2362e6SHarvey Harrison def_bool X86_64 926506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 927a7f7f624SMasahiro Yamada help 928506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 929506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 930506f1d07SSam Ravnborg present. 931506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 932506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 933506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 9344e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 9354e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 936506f1d07SSam Ravnborg 937506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 938506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 939506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 940506f1d07SSam Ravnborg 941506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 942506f1d07SSam Ravnborg 943506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 9443c2362e6SHarvey Harrison def_bool y 9453228e1dcSAnand K Mistry depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 946506f1d07SSam Ravnborg 9476a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 948506f1d07SSam Ravnborg# The code disables itself when not needed. 9497ae9392cSThomas Petazzoniconfig DMI 9507ae9392cSThomas Petazzoni default y 951cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9526a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 953a7f7f624SMasahiro Yamada help 9547ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9557ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9567ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9577ae9392cSThomas Petazzoni BIOS code. 9587ae9392cSThomas Petazzoni 959506f1d07SSam Ravnborgconfig GART_IOMMU 96038901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 961a4ce5a48SChristoph Hellwig select IOMMU_HELPER 962506f1d07SSam Ravnborg select SWIOTLB 96323ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 964a7f7f624SMasahiro Yamada help 965ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 966ced3c42cSIngo Molnar GART based hardware IOMMUs. 967ced3c42cSIngo Molnar 968ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 969ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 970ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 971ced3c42cSIngo Molnar 972ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 973ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 974ced3c42cSIngo Molnar 975ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 976ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 977ced3c42cSIngo Molnar 32-bit limited device. 978ced3c42cSIngo Molnar 979ced3c42cSIngo Molnar If unsure, say Y. 980506f1d07SSam Ravnborg 9818b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT 9828b766b0fSMichal Suchanek bool 9838b766b0fSMichal Suchanek help 9848b766b0fSMichal Suchanek If true, at least one selected framebuffer driver can take advantage 9858b766b0fSMichal Suchanek of VESA video modes set at an early boot stage via the vga= parameter. 9868b766b0fSMichal Suchanek 9871184dc2fSMike Travisconfig MAXSMP 988ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9896ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 99036f5101aSMike Travis select CPUMASK_OFFSTACK 991a7f7f624SMasahiro Yamada help 992ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9931184dc2fSMike Travis If unsure, say N. 994506f1d07SSam Ravnborg 995aec6487eSIngo Molnar# 996aec6487eSIngo Molnar# The maximum number of CPUs supported: 997aec6487eSIngo Molnar# 998aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 999aec6487eSIngo Molnar# and which can be configured interactively in the 1000aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 1001aec6487eSIngo Molnar# 1002aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 1003aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 1004aec6487eSIngo Molnar# 1005aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 1006aec6487eSIngo Molnar# interactive configuration. ) 1007aec6487eSIngo Molnar# 1008a0d0bb4dSRandy Dunlap 1009aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 1010a0d0bb4dSRandy Dunlap int 1011aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 1012a0d0bb4dSRandy Dunlap default 1 if !SMP 1013a0d0bb4dSRandy Dunlap default 2 1014a0d0bb4dSRandy Dunlap 1015aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 1016a0d0bb4dSRandy Dunlap int 1017a0d0bb4dSRandy Dunlap depends on X86_32 10180abf5086SArnd Bergmann default 8 if SMP 1019a0d0bb4dSRandy Dunlap default 1 if !SMP 1020a0d0bb4dSRandy Dunlap 1021aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 1022a0d0bb4dSRandy Dunlap int 1023a0d0bb4dSRandy Dunlap depends on X86_64 10241edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 10251edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 1026a0d0bb4dSRandy Dunlap default 1 if !SMP 1027aec6487eSIngo Molnar 1028aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 1029aec6487eSIngo Molnar int 1030aec6487eSIngo Molnar depends on X86_32 1031aec6487eSIngo Molnar default 8 if SMP 1032aec6487eSIngo Molnar default 1 if !SMP 1033aec6487eSIngo Molnar 1034aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 1035aec6487eSIngo Molnar int 1036aec6487eSIngo Molnar depends on X86_64 1037a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 1038a0d0bb4dSRandy Dunlap default 64 if SMP 1039aec6487eSIngo Molnar default 1 if !SMP 1040a0d0bb4dSRandy Dunlap 1041506f1d07SSam Ravnborgconfig NR_CPUS 104236f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 1043aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1044aec6487eSIngo Molnar default NR_CPUS_DEFAULT 1045a7f7f624SMasahiro Yamada help 1046506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 1047bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1048cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 1049506f1d07SSam Ravnborg minimum value which makes sense is 2. 1050506f1d07SSam Ravnborg 1051aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 1052aec6487eSIngo Molnar to the kernel image. 1053506f1d07SSam Ravnborg 105466558b73STim Chenconfig SCHED_CLUSTER 105566558b73STim Chen bool "Cluster scheduler support" 105666558b73STim Chen depends on SMP 105766558b73STim Chen default y 105866558b73STim Chen help 105966558b73STim Chen Cluster scheduler support improves the CPU scheduler's decision 106066558b73STim Chen making when dealing with machines that have clusters of CPUs. 106166558b73STim Chen Cluster usually means a couple of CPUs which are placed closely 106266558b73STim Chen by sharing mid-level caches, last-level cache tags or internal 106366558b73STim Chen busses. 106466558b73STim Chen 1065506f1d07SSam Ravnborgconfig SCHED_SMT 1066dbe73364SThomas Gleixner def_bool y if SMP 1067506f1d07SSam Ravnborg 1068506f1d07SSam Ravnborgconfig SCHED_MC 10693c2362e6SHarvey Harrison def_bool y 10703c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1071c8e56d20SBorislav Petkov depends on SMP 1072a7f7f624SMasahiro Yamada help 1073506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1074506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1075506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1076506f1d07SSam Ravnborg 1077de966cf4STim Chenconfig SCHED_MC_PRIO 1078de966cf4STim Chen bool "CPU core priorities scheduler support" 10793598e577SMeng Li depends on SCHED_MC 10803598e577SMeng Li select X86_INTEL_PSTATE if CPU_SUP_INTEL 10813598e577SMeng Li select X86_AMD_PSTATE if CPU_SUP_AMD && ACPI 10820a21fc12SIngo Molnar select CPU_FREQ 1083de966cf4STim Chen default y 1084a7f7f624SMasahiro Yamada help 1085de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1086de966cf4STim Chen core ordering determined at manufacturing time, which allows 1087de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1088de966cf4STim Chen single threaded workloads) than others. 1089de966cf4STim Chen 1090de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1091de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1092de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1093de966cf4STim Chen overall system performance can be achieved. 1094de966cf4STim Chen 1095de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1096de966cf4STim Chen 1097de966cf4STim Chen If unsure say Y here. 10985e76b2abSTim Chen 109930b8b006SThomas Gleixnerconfig UP_LATE_INIT 110030b8b006SThomas Gleixner def_bool y 1101ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 110230b8b006SThomas Gleixner 1103506f1d07SSam Ravnborgconfig X86_UP_APIC 110450849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 110550849eefSJan Beulich default PCI_MSI 110638a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1107a7f7f624SMasahiro Yamada help 1108506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1109506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1110506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1111506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1112506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1113506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1114506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1115506f1d07SSam Ravnborg lockups. 1116506f1d07SSam Ravnborg 1117506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1118506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1119506f1d07SSam Ravnborg depends on X86_UP_APIC 1120a7f7f624SMasahiro Yamada help 1121506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1122506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1123506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1124506f1d07SSam Ravnborg 1125506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1126506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1127506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1128506f1d07SSam Ravnborg 1129506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 11303c2362e6SHarvey Harrison def_bool y 11310dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1132b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 1133506f1d07SSam Ravnborg 11342b5e22afSKirill A. Shutemovconfig ACPI_MADT_WAKEUP 11352b5e22afSKirill A. Shutemov def_bool y 11362b5e22afSKirill A. Shutemov depends on X86_64 11372b5e22afSKirill A. Shutemov depends on ACPI 11382b5e22afSKirill A. Shutemov depends on SMP 11392b5e22afSKirill A. Shutemov depends on X86_LOCAL_APIC 11402b5e22afSKirill A. Shutemov 1141506f1d07SSam Ravnborgconfig X86_IO_APIC 1142b1da1e71SJan Beulich def_bool y 1143b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1144506f1d07SSam Ravnborg 114541b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 114641b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 114741b9eb26SStefan Assmann depends on X86_IO_APIC 1148a7f7f624SMasahiro Yamada help 114941b9eb26SStefan Assmann This option enables a workaround that fixes a source of 115041b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 115141b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 115241b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 115341b9eb26SStefan Assmann 115441b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 115541b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 115641b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 115741b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 115841b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 115941b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 116041b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 116141b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 116241b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 116341b9eb26SStefan Assmann down (vital) interrupt lines. 116441b9eb26SStefan Assmann 116541b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 116641b9eb26SStefan Assmann increased on these systems. 116741b9eb26SStefan Assmann 1168506f1d07SSam Ravnborgconfig X86_MCE 1169bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1170648ed940SChen, Gong select GENERIC_ALLOCATOR 1171e57dbaf7SBorislav Petkov default y 1172a7f7f624SMasahiro Yamada help 1173bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1174bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1175506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1176bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11774efc0670SAndi Kleen 11785de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11795de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11805de97c9fSTony Luck depends on X86_MCE 1181a7f7f624SMasahiro Yamada help 11825de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11835de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11845de97c9fSTony Luck rasdaemon solution. 11855de97c9fSTony Luck 1186506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11873c2362e6SHarvey Harrison def_bool y 11883c2362e6SHarvey Harrison prompt "Intel MCE features" 1189c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1190a7f7f624SMasahiro Yamada help 1191506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1192506f1d07SSam Ravnborg the thermal monitor. 1193506f1d07SSam Ravnborg 1194506f1d07SSam Ravnborgconfig X86_MCE_AMD 11953c2362e6SHarvey Harrison def_bool y 11963c2362e6SHarvey Harrison prompt "AMD MCE features" 1197d35fb312SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC 1198a7f7f624SMasahiro Yamada help 1199506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1200506f1d07SSam Ravnborg the DRAM Error Threshold. 1201506f1d07SSam Ravnborg 12024efc0670SAndi Kleenconfig X86_ANCIENT_MCE 12036fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1204c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1205a7f7f624SMasahiro Yamada help 12064efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 12075065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 12084efc0670SAndi Kleen line. 12094efc0670SAndi Kleen 1210b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1211b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 12126fc108a0SJan Beulich def_bool y 1213b2762686SAndi Kleen 1214ea149b36SAndi Kleenconfig X86_MCE_INJECT 1215bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1216ea149b36SAndi Kleen tristate "Machine check injector support" 1217a7f7f624SMasahiro Yamada help 1218ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1219ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1220ea149b36SAndi Kleen QA it is safe to say n. 1221ea149b36SAndi Kleen 122207dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1223e633c65aSKan Liang 12245aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 12251e642812SIngo Molnar bool "Legacy VM86 support" 1226506f1d07SSam Ravnborg depends on X86_32 1227a7f7f624SMasahiro Yamada help 12285aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 12295aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 12305aef51c3SAndy Lutomirski 12315aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 12325aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 12335aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 12345aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 12355aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 12361e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 12371e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 12381e642812SIngo Molnar mode might be faster than emulation and you might want to 12391e642812SIngo Molnar enable this option. 12405aef51c3SAndy Lutomirski 12411e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 12421e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 12431e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 12441e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 12455aef51c3SAndy Lutomirski 12461e642812SIngo Molnar Enabling this option increases the complexity of the kernel 12471e642812SIngo Molnar and slows down exception handling a tiny bit. 12485aef51c3SAndy Lutomirski 12491e642812SIngo Molnar If unsure, say N here. 12505aef51c3SAndy Lutomirski 12515aef51c3SAndy Lutomirskiconfig VM86 12525aef51c3SAndy Lutomirski bool 12535aef51c3SAndy Lutomirski default X86_LEGACY_VM86 125434273f41SH. Peter Anvin 125534273f41SH. Peter Anvinconfig X86_16BIT 125634273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 125734273f41SH. Peter Anvin default y 1258a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1259a7f7f624SMasahiro Yamada help 126034273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 126134273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 126234273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 126334273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 126434273f41SH. Peter Anvin 126534273f41SH. Peter Anvinconfig X86_ESPFIX32 126634273f41SH. Peter Anvin def_bool y 126734273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1268506f1d07SSam Ravnborg 1269197725deSH. Peter Anvinconfig X86_ESPFIX64 1270197725deSH. Peter Anvin def_bool y 127134273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1272506f1d07SSam Ravnborg 12731ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12741ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12751ad83c85SAndy Lutomirski default y 12761ad83c85SAndy Lutomirski depends on X86_64 1277a7f7f624SMasahiro Yamada help 12781ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12791ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12801ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12811ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12821ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12831ad83c85SAndy Lutomirski 0xffffffffff600?00. 12841ad83c85SAndy Lutomirski 12851ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12861ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12871ad83c85SAndy Lutomirski 12881ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12891ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12901ad83c85SAndy Lutomirski 1291111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1292111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1293a24ca997SThomas Gleixner default y 1294a7f7f624SMasahiro Yamada help 1295111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1296111e7b15SThomas Gleixner for legacy applications. 1297111e7b15SThomas Gleixner 1298c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1299c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1300c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1301c8137aceSThomas Gleixner capabilities and permission from potentially active security 1302c8137aceSThomas Gleixner modules. 1303c8137aceSThomas Gleixner 1304c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1305c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1306a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1307a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1308c8137aceSThomas Gleixner 1309506f1d07SSam Ravnborgconfig TOSHIBA 1310506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1311506f1d07SSam Ravnborg depends on X86_32 1312a7f7f624SMasahiro Yamada help 1313506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1314506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1315506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1316506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1317506f1d07SSam Ravnborg 1318506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1319506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1320506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1321506f1d07SSam Ravnborg 1322506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1323506f1d07SSam Ravnborg Say N otherwise. 1324506f1d07SSam Ravnborg 1325506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 13269ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 13279ba16087SJan Beulich depends on X86_32 1328a7f7f624SMasahiro Yamada help 1329506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1330506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1331506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1332506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1333506f1d07SSam Ravnborg system. 1334506f1d07SSam Ravnborg 1335506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 13365e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1337506f1d07SSam Ravnborg 1338506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1339506f1d07SSam Ravnborg enable this option even if you don't need it. 1340506f1d07SSam Ravnborg Say N otherwise. 1341506f1d07SSam Ravnborg 1342506f1d07SSam Ravnborgconfig MICROCODE 1343e6bcfdd7SThomas Gleixner def_bool y 134480030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 134580cc9f10SPeter Oruba 1346fdbd4381SThomas Gleixnerconfig MICROCODE_INITRD32 1347fdbd4381SThomas Gleixner def_bool y 1348fdbd4381SThomas Gleixner depends on MICROCODE && X86_32 && BLK_DEV_INITRD 1349fdbd4381SThomas Gleixner 1350a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING 1351a77a94f8SBorislav Petkov bool "Late microcode loading (DANGEROUS)" 1352c02f48e0SBorislav Petkov default n 1353634ac23aSThomas Gleixner depends on MICROCODE && SMP 1354a7f7f624SMasahiro Yamada help 1355a77a94f8SBorislav Petkov Loading microcode late, when the system is up and executing instructions 1356a77a94f8SBorislav Petkov is a tricky business and should be avoided if possible. Just the sequence 1357a77a94f8SBorislav Petkov of synchronizing all cores and SMT threads is one fragile dance which does 1358a77a94f8SBorislav Petkov not guarantee that cores might not softlock after the loading. Therefore, 13599407bda8SThomas Gleixner use this at your own risk. Late loading taints the kernel unless the 13609407bda8SThomas Gleixner microcode header indicates that it is safe for late loading via the 13619407bda8SThomas Gleixner minimal revision check. This minimal revision check can be enforced on 13629407bda8SThomas Gleixner the kernel command line with "microcode.minrev=Y". 13639407bda8SThomas Gleixner 13649407bda8SThomas Gleixnerconfig MICROCODE_LATE_FORCE_MINREV 13659407bda8SThomas Gleixner bool "Enforce late microcode loading minimal revision check" 13669407bda8SThomas Gleixner default n 13679407bda8SThomas Gleixner depends on MICROCODE_LATE_LOADING 13689407bda8SThomas Gleixner help 13699407bda8SThomas Gleixner To prevent that users load microcode late which modifies already 13709407bda8SThomas Gleixner in use features, newer microcode patches have a minimum revision field 13719407bda8SThomas Gleixner in the microcode header, which tells the kernel which minimum 13729407bda8SThomas Gleixner revision must be active in the CPU to safely load that new microcode 13739407bda8SThomas Gleixner late into the running system. If disabled the check will not 13749407bda8SThomas Gleixner be enforced but the kernel will be tainted when the minimal 13759407bda8SThomas Gleixner revision check fails. 13769407bda8SThomas Gleixner 13779407bda8SThomas Gleixner This minimal revision check can also be controlled via the 13789407bda8SThomas Gleixner "microcode.minrev" parameter on the kernel command line. 13799407bda8SThomas Gleixner 13809407bda8SThomas Gleixner If unsure say Y. 1381506f1d07SSam Ravnborg 1382506f1d07SSam Ravnborgconfig X86_MSR 1383506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1384a7f7f624SMasahiro Yamada help 1385506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1386506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1387506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1388506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1389506f1d07SSam Ravnborg systems. 1390506f1d07SSam Ravnborg 1391506f1d07SSam Ravnborgconfig X86_CPUID 1392506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1393a7f7f624SMasahiro Yamada help 1394506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1395506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1396506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1397506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1398506f1d07SSam Ravnborg 1399bbeb69ceSArnd Bergmannconfig HIGHMEM4G 1400bbeb69ceSArnd Bergmann bool "High Memory Support" 1401506f1d07SSam Ravnborg depends on X86_32 1402a7f7f624SMasahiro Yamada help 1403bbeb69ceSArnd Bergmann Linux can use up to 4 Gigabytes of physical memory on x86 systems. 1404506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1405506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1406506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1407506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1408506f1d07SSam Ravnborg "high memory". 1409506f1d07SSam Ravnborg 1410506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1411506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1412506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1413506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1414506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1415506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1416506f1d07SSam Ravnborg possible. 1417506f1d07SSam Ravnborg 1418506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1419bbeb69ceSArnd Bergmann answer "Y" here. 1420506f1d07SSam Ravnborg 1421bbeb69ceSArnd Bergmann If unsure, say N. 1422506f1d07SSam Ravnborg 1423506f1d07SSam Ravnborgchoice 14246a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1425506f1d07SSam Ravnborg default VMSPLIT_3G 1426506f1d07SSam Ravnborg depends on X86_32 1427a7f7f624SMasahiro Yamada help 1428506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1429506f1d07SSam Ravnborg 1430506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1431506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1432506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1433506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1434506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1435506f1d07SSam Ravnborg available to user programs, making the address space there 1436506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1437506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1438506f1d07SSam Ravnborg kernel modules. 1439506f1d07SSam Ravnborg 1440506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1441506f1d07SSam Ravnborg option alone! 1442506f1d07SSam Ravnborg 1443506f1d07SSam Ravnborg config VMSPLIT_3G 1444506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1445506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1446506f1d07SSam Ravnborg depends on !X86_PAE 1447506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1448506f1d07SSam Ravnborg config VMSPLIT_2G 1449506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1450506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1451506f1d07SSam Ravnborg depends on !X86_PAE 1452506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1453506f1d07SSam Ravnborg config VMSPLIT_1G 1454506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1455506f1d07SSam Ravnborgendchoice 1456506f1d07SSam Ravnborg 1457506f1d07SSam Ravnborgconfig PAGE_OFFSET 1458506f1d07SSam Ravnborg hex 1459506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1460506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1461506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1462506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1463506f1d07SSam Ravnborg default 0xC0000000 1464506f1d07SSam Ravnborg depends on X86_32 1465506f1d07SSam Ravnborg 1466506f1d07SSam Ravnborgconfig HIGHMEM 1467bbeb69ceSArnd Bergmann def_bool HIGHMEM4G 1468506f1d07SSam Ravnborg 1469506f1d07SSam Ravnborgconfig X86_PAE 14709ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 147188a2b4edSArnd Bergmann depends on X86_32 && X86_HAVE_PAE 1472d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 1473a7f7f624SMasahiro Yamada help 1474506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1475506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1476506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1477506f1d07SSam Ravnborg consumes more pagetable space per process. 1478506f1d07SSam Ravnborg 147977ef56e4SKirill A. Shutemovconfig X86_5LEVEL 148077ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 148118ec1eafSKirill A. Shutemov default y 1482eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1483162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 148477ef56e4SKirill A. Shutemov depends on X86_64 1485a7f7f624SMasahiro Yamada help 148677ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 148777ef56e4SKirill A. Shutemov up to 128 PiB of virtual address space and 4 PiB of 148877ef56e4SKirill A. Shutemov physical address space. 148977ef56e4SKirill A. Shutemov 149077ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 149177ef56e4SKirill A. Shutemov 14926657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 14936657fca0SKirill A. Shutemov support 4- or 5-level paging. 149477ef56e4SKirill A. Shutemov 1495ff61f079SJonathan Corbet See Documentation/arch/x86/x86_64/5level-paging.rst for more 149677ef56e4SKirill A. Shutemov information. 149777ef56e4SKirill A. Shutemov 149877ef56e4SKirill A. Shutemov Say N if unsure. 149977ef56e4SKirill A. Shutemov 150010971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1501e5008abeSLuis R. Rodriguez def_bool y 15022e1da13fSVlastimil Babka depends on X86_64 1503a7f7f624SMasahiro Yamada help 150410971ab2SIngo Molnar Certain kernel features effectively disable kernel 150510971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 150610971ab2SIngo Molnar supports them), so don't confuse the user by printing 150710971ab2SIngo Molnar that we have them enabled. 15089e899816SNick Piggin 15095c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15105c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15115c280cf6SThomas Gleixner depends on DEBUG_FS 1512a7f7f624SMasahiro Yamada help 1513b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1514a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15155c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15165c280cf6SThomas Gleixner 151720f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT 151820f07a04SKirill A. Shutemov select ARCH_HAS_FORCE_DMA_UNENCRYPTED 151920f07a04SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 152020f07a04SKirill A. Shutemov def_bool n 152120f07a04SKirill A. Shutemov 15227744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15237744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15247744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 15256c321179STom Lendacky depends on EFI_STUB 152682fef0adSDavid Rientjes select DMA_COHERENT_POOL 1527ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 1528597cfe48SJoerg Roedel select INSTRUCTION_DECODER 1529aa5a4611STom Lendacky select ARCH_HAS_CC_PLATFORM 153020f07a04SKirill A. Shutemov select X86_MEM_ENCRYPT 15316c321179STom Lendacky select UNACCEPTED_MEMORY 1532c5529418SNikunj A Dadhania select CRYPTO_LIB_AESGCM 1533a7f7f624SMasahiro Yamada help 15347744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15357744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15367744ccdbSTom Lendacky Encryption (SME). 15377744ccdbSTom Lendacky 1538506f1d07SSam Ravnborg# Common NUMA Features 1539506f1d07SSam Ravnborgconfig NUMA 1540e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1541506f1d07SSam Ravnborg depends on SMP 15420abf5086SArnd Bergmann depends on X86_64 15437ecd19cfSKefeng Wang select USE_PERCPU_NUMA_NODE_ID 15440c436a58SSaurabh Sengar select OF_NUMA if OF 1545a7f7f624SMasahiro Yamada help 1546e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1547fd51b2d7SKOSAKI Motohiro 1548506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1549506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1550506f1d07SSam Ravnborg NUMA awareness to the kernel. 1551506f1d07SSam Ravnborg 1552c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1553fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1554fd51b2d7SKOSAKI Motohiro 1555fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1556506f1d07SSam Ravnborg 1557eec1d4faSHans Rosenfeldconfig AMD_NUMA 15583c2362e6SHarvey Harrison def_bool y 15593c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15605da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1561a7f7f624SMasahiro Yamada help 1562eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1563eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1564eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1565eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1566eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1567506f1d07SSam Ravnborg 1568506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 15693c2362e6SHarvey Harrison def_bool y 15703c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1571506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1572506f1d07SSam Ravnborg select ACPI_NUMA 1573a7f7f624SMasahiro Yamada help 1574506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1575506f1d07SSam Ravnborg 1576506f1d07SSam Ravnborgconfig NODES_SHIFT 1577d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 157851591e31SDavid Rientjes range 1 10 157951591e31SDavid Rientjes default "10" if MAXSMP 1580506f1d07SSam Ravnborg default "6" if X86_64 1581506f1d07SSam Ravnborg default "3" 1582a9ee6cf5SMike Rapoport depends on NUMA 1583a7f7f624SMasahiro Yamada help 15841184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1585692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1586506f1d07SSam Ravnborg 1587506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1588506f1d07SSam Ravnborg def_bool y 15893b16651fSTejun Heo depends on X86_32 && !NUMA 1590506f1d07SSam Ravnborg 1591506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1592506f1d07SSam Ravnborg def_bool y 15936ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1594506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1595506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1596506f1d07SSam Ravnborg 15973b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 15986ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 15993b16651fSTejun Heo 1600506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1601506f1d07SSam Ravnborg def_bool y 16024eda2bc3SDavid Hildenbrand depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE 1603506f1d07SSam Ravnborg 1604506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1605a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16065c11f00bSDavid Hildenbrand depends on MEMORY_HOTPLUG 1607a0842b70SToshi Kani help 1608a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1609cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1610a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1611506f1d07SSam Ravnborg 16123b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16133b16651fSTejun Heo def_bool y 16143b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16153b16651fSTejun Heo 1616a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1617a29815a3SAvi Kivity hex 1618a29815a3SAvi Kivity default 0 if X86_32 1619a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1620a29815a3SAvi Kivity 16217a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16227a67832cSDan Williams bool 16237a67832cSDan Williams 1624ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16257a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16269f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16279f53f9faSDan Williams depends on BLK_DEV 16287a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16297b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16309f53f9faSDan Williams select LIBNVDIMM 1631ec776ef6SChristoph Hellwig help 1632ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1633ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1634ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1635ec776ef6SChristoph Hellwig they can be used for persistent storage. 1636ec776ef6SChristoph Hellwig 1637ec776ef6SChristoph Hellwig Say Y if unsure. 1638ec776ef6SChristoph Hellwig 16399f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16409f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1641a7f7f624SMasahiro Yamada help 16429f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16439f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16449f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 16459f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 16469f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 16479f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 16489f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 16498c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 16509f077871SJeremy Fitzhardinge 16519f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 16529f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 16539f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 16549f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 16559f077871SJeremy Fitzhardinge 16569f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 16579f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 16589f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 16599f077871SJeremy Fitzhardinge memory. 16609f077871SJeremy Fitzhardinge 1661c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1662c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1663c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1664c885df50SJeremy Fitzhardinge default y 1665a7f7f624SMasahiro Yamada help 1666c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1667c885df50SJeremy Fitzhardinge on or off. 1668c885df50SJeremy Fitzhardinge 1669506f1d07SSam Ravnborgconfig MATH_EMULATION 1670506f1d07SSam Ravnborg bool 1671a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 167287d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1673a7f7f624SMasahiro Yamada help 1674506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1675506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1676506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1677506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1678506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1679506f1d07SSam Ravnborg coprocessor or this emulation. 1680506f1d07SSam Ravnborg 1681506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1682506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1683506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1684506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1685506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1686506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1687506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1688506f1d07SSam Ravnborg intend to use this kernel on different machines. 1689506f1d07SSam Ravnborg 1690506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1691506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1692506f1d07SSam Ravnborg 1693506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1694506f1d07SSam Ravnborg kernel, it won't hurt. 1695506f1d07SSam Ravnborg 1696506f1d07SSam Ravnborgconfig MTRR 16976fc108a0SJan Beulich def_bool y 16986a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1699a7f7f624SMasahiro Yamada help 1700506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1701506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1702506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1703506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1704506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1705506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1706506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1707506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1708506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1709506f1d07SSam Ravnborg 1710506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1711506f1d07SSam Ravnborg control registers on other processors can be easily supported 1712506f1d07SSam Ravnborg as well: 1713506f1d07SSam Ravnborg 1714506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1715506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1716506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1717506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1718506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1719506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1720506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1721506f1d07SSam Ravnborg 1722506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1723506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1724506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1725506f1d07SSam Ravnborg 1726506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1727506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1728506f1d07SSam Ravnborg 1729ff61f079SJonathan Corbet See <file:Documentation/arch/x86/mtrr.rst> for more information. 1730506f1d07SSam Ravnborg 173195ffa243SYinghai Luconfig MTRR_SANITIZER 17322ffb3501SYinghai Lu def_bool y 173395ffa243SYinghai Lu prompt "MTRR cleanup support" 173495ffa243SYinghai Lu depends on MTRR 1735a7f7f624SMasahiro Yamada help 1736aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1737aba3728cSThomas Gleixner add writeback entries. 173895ffa243SYinghai Lu 1739aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1740692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1741aba3728cSThomas Gleixner mtrr_chunk_size. 174295ffa243SYinghai Lu 17432ffb3501SYinghai Lu If unsure, say Y. 174495ffa243SYinghai Lu 174595ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1746f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1747f5098d62SYinghai Lu range 0 1 1748f5098d62SYinghai Lu default "0" 174995ffa243SYinghai Lu depends on MTRR_SANITIZER 1750a7f7f624SMasahiro Yamada help 1751f5098d62SYinghai Lu Enable mtrr cleanup default value 175295ffa243SYinghai Lu 175312031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 175412031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 175512031a62SYinghai Lu range 0 7 175612031a62SYinghai Lu default "1" 175712031a62SYinghai Lu depends on MTRR_SANITIZER 1758a7f7f624SMasahiro Yamada help 175912031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1760aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 176112031a62SYinghai Lu 17622e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 17636fc108a0SJan Beulich def_bool y 17646a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 17652a8a2719SIngo Molnar depends on MTRR 17667a87225aSMatthew Wilcox (Oracle) select ARCH_USES_PG_ARCH_2 1767a7f7f624SMasahiro Yamada help 17682e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1769042b78e4SVenki Pallipadi 17702e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 17712e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 17722e5d9c85Svenkatesh.pallipadi@intel.com 17732e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1774042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 17752e5d9c85Svenkatesh.pallipadi@intel.com 17762e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 17772e5d9c85Svenkatesh.pallipadi@intel.com 1778b971880fSBabu Mogerconfig X86_UMIP 1779796ebc81SRicardo Neri def_bool y 1780b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1781a7f7f624SMasahiro Yamada help 1782b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1783b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1784b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1785b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1786b971880fSBabu Moger information about the hardware state. 1787796ebc81SRicardo Neri 1788796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1789796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1790796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1791796ebc81SRicardo Neri results are dummy. 1792aa35f896SRicardo Neri 1793156ff4a5SPeter Zijlstraconfig CC_HAS_IBT 1794156ff4a5SPeter Zijlstra # GCC >= 9 and binutils >= 2.29 1795156ff4a5SPeter Zijlstra # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 1796156ff4a5SPeter Zijlstra # Clang/LLVM >= 14 1797262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f 1798262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 1799156ff4a5SPeter Zijlstra def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ 1800262448f3SNathan Chancellor (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ 1801156ff4a5SPeter Zijlstra $(as-instr,endbr64) 1802156ff4a5SPeter Zijlstra 180318e66b69SRick Edgecombeconfig X86_CET 180418e66b69SRick Edgecombe def_bool n 180518e66b69SRick Edgecombe help 180618e66b69SRick Edgecombe CET features configured (Shadow stack or IBT) 180718e66b69SRick Edgecombe 1808156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT 1809156ff4a5SPeter Zijlstra prompt "Indirect Branch Tracking" 18104fd5f70cSKees Cook def_bool y 181103f16cd0SJosh Poimboeuf depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL 1812f6a2c2b2SNathan Chancellor # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f 1813f6a2c2b2SNathan Chancellor depends on !LD_IS_LLD || LLD_VERSION >= 140000 181403f16cd0SJosh Poimboeuf select OBJTOOL 181518e66b69SRick Edgecombe select X86_CET 1816156ff4a5SPeter Zijlstra help 1817156ff4a5SPeter Zijlstra Build the kernel with support for Indirect Branch Tracking, a 1818156ff4a5SPeter Zijlstra hardware support course-grain forward-edge Control Flow Integrity 1819156ff4a5SPeter Zijlstra protection. It enforces that all indirect calls must land on 1820156ff4a5SPeter Zijlstra an ENDBR instruction, as such, the compiler will instrument the 1821156ff4a5SPeter Zijlstra code with them to make this happen. 1822156ff4a5SPeter Zijlstra 1823ed53a0d9SPeter Zijlstra In addition to building the kernel with IBT, seal all functions that 18244cdfc11bSNur Hussein are not indirect call targets, avoiding them ever becoming one. 1825ed53a0d9SPeter Zijlstra 1826ed53a0d9SPeter Zijlstra This requires LTO like objtool runs and will slow down the build. It 1827ed53a0d9SPeter Zijlstra does significantly reduce the number of ENDBR instructions in the 1828ed53a0d9SPeter Zijlstra kernel image. 1829ed53a0d9SPeter Zijlstra 183035e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 183138f3e775SBabu Moger prompt "Memory Protection Keys" 183235e97790SDave Hansen def_bool y 1833284244a9SDave Hansen # Note: only available in 64-bit mode 183438f3e775SBabu Moger depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 183552c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 183652c8e601SIngo Molnar select ARCH_HAS_PKEYS 1837a7f7f624SMasahiro Yamada help 1838284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1839284244a9SDave Hansen page-based protections, but without requiring modification of the 1840284244a9SDave Hansen page tables when an application changes protection domains. 1841284244a9SDave Hansen 18421eecbcdcSMauro Carvalho Chehab For details, see Documentation/core-api/protection-keys.rst 1843284244a9SDave Hansen 1844284244a9SDave Hansen If unsure, say y. 184535e97790SDave Hansen 18465626f8d4SJoey Goulyconfig ARCH_PKEY_BITS 18475626f8d4SJoey Gouly int 18485626f8d4SJoey Gouly default 4 18495626f8d4SJoey Gouly 1850db616173SMichal Hockochoice 1851db616173SMichal Hocko prompt "TSX enable mode" 1852db616173SMichal Hocko depends on CPU_SUP_INTEL 1853db616173SMichal Hocko default X86_INTEL_TSX_MODE_OFF 1854db616173SMichal Hocko help 1855db616173SMichal Hocko Intel's TSX (Transactional Synchronization Extensions) feature 1856db616173SMichal Hocko allows to optimize locking protocols through lock elision which 1857db616173SMichal Hocko can lead to a noticeable performance boost. 1858db616173SMichal Hocko 1859db616173SMichal Hocko On the other hand it has been shown that TSX can be exploited 1860db616173SMichal Hocko to form side channel attacks (e.g. TAA) and chances are there 1861db616173SMichal Hocko will be more of those attacks discovered in the future. 1862db616173SMichal Hocko 1863db616173SMichal Hocko Therefore TSX is not enabled by default (aka tsx=off). An admin 1864db616173SMichal Hocko might override this decision by tsx=on the command line parameter. 1865db616173SMichal Hocko Even with TSX enabled, the kernel will attempt to enable the best 1866db616173SMichal Hocko possible TAA mitigation setting depending on the microcode available 1867db616173SMichal Hocko for the particular machine. 1868db616173SMichal Hocko 1869db616173SMichal Hocko This option allows to set the default tsx mode between tsx=on, =off 1870db616173SMichal Hocko and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1871db616173SMichal Hocko details. 1872db616173SMichal Hocko 1873db616173SMichal Hocko Say off if not sure, auto if TSX is in use but it should be used on safe 1874db616173SMichal Hocko platforms or on if TSX is in use and the security aspect of tsx is not 1875db616173SMichal Hocko relevant. 1876db616173SMichal Hocko 1877db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF 1878db616173SMichal Hocko bool "off" 1879db616173SMichal Hocko help 1880db616173SMichal Hocko TSX is disabled if possible - equals to tsx=off command line parameter. 1881db616173SMichal Hocko 1882db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON 1883db616173SMichal Hocko bool "on" 1884db616173SMichal Hocko help 1885db616173SMichal Hocko TSX is always enabled on TSX capable HW - equals the tsx=on command 1886db616173SMichal Hocko line parameter. 1887db616173SMichal Hocko 1888db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO 1889db616173SMichal Hocko bool "auto" 1890db616173SMichal Hocko help 1891db616173SMichal Hocko TSX is enabled on TSX capable HW that is believed to be safe against 1892db616173SMichal Hocko side channel attacks- equals the tsx=auto command line parameter. 1893db616173SMichal Hockoendchoice 1894db616173SMichal Hocko 1895e7e05452SSean Christophersonconfig X86_SGX 1896e7e05452SSean Christopherson bool "Software Guard eXtensions (SGX)" 1897b8d1d163SDaniel Sneddon depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC 1898e7e05452SSean Christopherson depends on CRYPTO=y 1899e7e05452SSean Christopherson depends on CRYPTO_SHA256=y 1900e7e05452SSean Christopherson select MMU_NOTIFIER 1901901ddbb9SJarkko Sakkinen select NUMA_KEEP_MEMINFO if NUMA 190240e0e784STony Luck select XARRAY_MULTI 1903e7e05452SSean Christopherson help 1904e7e05452SSean Christopherson Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1905e7e05452SSean Christopherson that can be used by applications to set aside private regions of code 1906e7e05452SSean Christopherson and data, referred to as enclaves. An enclave's private memory can 1907e7e05452SSean Christopherson only be accessed by code running within the enclave. Accesses from 1908e7e05452SSean Christopherson outside the enclave, including other enclaves, are disallowed by 1909e7e05452SSean Christopherson hardware. 1910e7e05452SSean Christopherson 1911e7e05452SSean Christopherson If unsure, say N. 1912e7e05452SSean Christopherson 191318e66b69SRick Edgecombeconfig X86_USER_SHADOW_STACK 191418e66b69SRick Edgecombe bool "X86 userspace shadow stack" 191518e66b69SRick Edgecombe depends on AS_WRUSS 191618e66b69SRick Edgecombe depends on X86_64 191718e66b69SRick Edgecombe select ARCH_USES_HIGH_VMA_FLAGS 1918bcc9d04eSMark Brown select ARCH_HAS_USER_SHADOW_STACK 191918e66b69SRick Edgecombe select X86_CET 192018e66b69SRick Edgecombe help 192118e66b69SRick Edgecombe Shadow stack protection is a hardware feature that detects function 192218e66b69SRick Edgecombe return address corruption. This helps mitigate ROP attacks. 192318e66b69SRick Edgecombe Applications must be enabled to use it, and old userspace does not 192418e66b69SRick Edgecombe get protection "for free". 192518e66b69SRick Edgecombe 192618e66b69SRick Edgecombe CPUs supporting shadow stacks were first released in 2020. 192718e66b69SRick Edgecombe 192854acee60SDave Hansen See Documentation/arch/x86/shstk.rst for more information. 192918e66b69SRick Edgecombe 193018e66b69SRick Edgecombe If unsure, say N. 193118e66b69SRick Edgecombe 1932c33621b4SKai Huangconfig INTEL_TDX_HOST 1933c33621b4SKai Huang bool "Intel Trust Domain Extensions (TDX) host support" 1934c33621b4SKai Huang depends on CPU_SUP_INTEL 1935c33621b4SKai Huang depends on X86_64 1936c33621b4SKai Huang depends on KVM_INTEL 19373115cabdSKai Huang depends on X86_X2APIC 1938abe8dbabSKai Huang select ARCH_KEEP_MEMBLOCK 1939ac3a2208SKai Huang depends on CONTIG_ALLOC 1940cb8eb06dSDave Hansen depends on !KEXEC_CORE 194183e1bdc9SKai Huang depends on X86_MCE 1942c33621b4SKai Huang help 1943c33621b4SKai Huang Intel Trust Domain Extensions (TDX) protects guest VMs from malicious 1944c33621b4SKai Huang host and certain physical attacks. This option enables necessary TDX 1945c33621b4SKai Huang support in the host kernel to run confidential VMs. 1946c33621b4SKai Huang 1947c33621b4SKai Huang If unsure, say N. 1948c33621b4SKai Huang 1949506f1d07SSam Ravnborgconfig EFI 19509ba16087SJan Beulich bool "EFI runtime service support" 19515b83683fSHuang, Ying depends on ACPI 1952f6ce5002SSergey Vlasov select UCS2_STRING 1953022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 19541ff2fc02STom Lendacky select ARCH_USE_MEMREMAP_PROT 1955aba7e066SArd Biesheuvel select EFI_RUNTIME_MAP if KEXEC_CORE 1956a7f7f624SMasahiro Yamada help 19578b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1958506f1d07SSam Ravnborg available (such as the EFI variable services). 1959506f1d07SSam Ravnborg 19608b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19618b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19628b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19638b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19648b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19658b2cb7a8SHuang, Ying platforms. 1966506f1d07SSam Ravnborg 1967291f3632SMatt Flemingconfig EFI_STUB 1968291f3632SMatt Fleming bool "EFI stub support" 1969c6dbd3e5SPeter Zijlstra depends on EFI 19707b2a583aSMatt Fleming select RELOCATABLE 1971a7f7f624SMasahiro Yamada help 1972291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1973291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1974291f3632SMatt Fleming 19754f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 19760c759662SMatt Fleming 1977cc3fdda2SArd Biesheuvelconfig EFI_HANDOVER_PROTOCOL 1978cc3fdda2SArd Biesheuvel bool "EFI handover protocol (DEPRECATED)" 1979cc3fdda2SArd Biesheuvel depends on EFI_STUB 1980cc3fdda2SArd Biesheuvel default y 1981cc3fdda2SArd Biesheuvel help 1982cc3fdda2SArd Biesheuvel Select this in order to include support for the deprecated EFI 1983cc3fdda2SArd Biesheuvel handover protocol, which defines alternative entry points into the 1984cc3fdda2SArd Biesheuvel EFI stub. This is a practice that has no basis in the UEFI 1985cc3fdda2SArd Biesheuvel specification, and requires a priori knowledge on the part of the 1986cc3fdda2SArd Biesheuvel bootloader about Linux/x86 specific ways of passing the command line 1987cc3fdda2SArd Biesheuvel and initrd, and where in memory those assets may be loaded. 1988cc3fdda2SArd Biesheuvel 1989cc3fdda2SArd Biesheuvel If in doubt, say Y. Even though the corresponding support is not 1990cc3fdda2SArd Biesheuvel present in upstream GRUB or other bootloaders, most distros build 1991cc3fdda2SArd Biesheuvel GRUB with numerous downstream patches applied, and may rely on the 1992cc3fdda2SArd Biesheuvel handover protocol as as result. 1993cc3fdda2SArd Biesheuvel 19947d453eeeSMatt Flemingconfig EFI_MIXED 19957d453eeeSMatt Fleming bool "EFI mixed-mode support" 19967d453eeeSMatt Fleming depends on EFI_STUB && X86_64 1997a7f7f624SMasahiro Yamada help 19987d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 19997d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 20007d453eeeSMatt Fleming mode. 20017d453eeeSMatt Fleming 20027d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 20037d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 20047d453eeeSMatt Fleming the EFI handover protocol must be used. 20057d453eeeSMatt Fleming 20067d453eeeSMatt Fleming If unsure, say N. 20077d453eeeSMatt Fleming 20081fff234dSArd Biesheuvelconfig EFI_RUNTIME_MAP 20091fff234dSArd Biesheuvel bool "Export EFI runtime maps to sysfs" if EXPERT 20101fff234dSArd Biesheuvel depends on EFI 20111fff234dSArd Biesheuvel help 20121fff234dSArd Biesheuvel Export EFI runtime memory regions to /sys/firmware/efi/runtime-map. 20131fff234dSArd Biesheuvel That memory map is required by the 2nd kernel to set up EFI virtual 20141fff234dSArd Biesheuvel mappings after kexec, but can also be used for debugging purposes. 20151fff234dSArd Biesheuvel 20161fff234dSArd Biesheuvel See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map. 20171fff234dSArd Biesheuvel 20188636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 2019506f1d07SSam Ravnborg 20206af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC 20216af51380SEric DeVolder def_bool y 2022506f1d07SSam Ravnborg 20236af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_FILE 2024c1ad12eeSArnd Bergmann def_bool X86_64 2025506f1d07SSam Ravnborg 20266af51380SEric DeVolderconfig ARCH_SELECTS_KEXEC_FILE 20276af51380SEric DeVolder def_bool y 20286af51380SEric DeVolder depends on KEXEC_FILE 2029b69a2afdSJonathan McDowell select HAVE_IMA_KEXEC if IMA 203074ca317cSVivek Goyal 2031e6265fe7SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_PURGATORY 2032c1ad12eeSArnd Bergmann def_bool y 2033b799a09fSAKASHI Takahiro 20346af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_SIG 20356af51380SEric DeVolder def_bool y 203699d5cadfSJiri Bohac 20376af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_SIG_FORCE 20386af51380SEric DeVolder def_bool y 203999d5cadfSJiri Bohac 20406af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG 20416af51380SEric DeVolder def_bool y 204299d5cadfSJiri Bohac 20436af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_JUMP 20446af51380SEric DeVolder def_bool y 20458e7d8381SVivek Goyal 20466af51380SEric DeVolderconfig ARCH_SUPPORTS_CRASH_DUMP 20476af51380SEric DeVolder def_bool X86_64 || (X86_32 && HIGHMEM) 20488e7d8381SVivek Goyal 204931daa343SDave Vasilevskyconfig ARCH_DEFAULT_CRASH_DUMP 205031daa343SDave Vasilevsky def_bool y 205131daa343SDave Vasilevsky 2052ea53ad9cSEric DeVolderconfig ARCH_SUPPORTS_CRASH_HOTPLUG 2053ea53ad9cSEric DeVolder def_bool y 20543ab83521SHuang Ying 20559c08a2a1SBaoquan Heconfig ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 205685fcde40SBaoquan He def_bool CRASH_RESERVE 20579c08a2a1SBaoquan He 2058506f1d07SSam Ravnborgconfig PHYSICAL_START 20596a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2060ceefccc9SH. Peter Anvin default "0x1000000" 2061a7f7f624SMasahiro Yamada help 2062506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2063506f1d07SSam Ravnborg 206443b1d3e6SChris Koch If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage 206543b1d3e6SChris Koch will decompress itself to above physical address and run from there. 206643b1d3e6SChris Koch Otherwise, bzImage will run from the address where it has been loaded 206743b1d3e6SChris Koch by the boot loader. The only exception is if it is loaded below the 206843b1d3e6SChris Koch above physical address, in which case it will relocate itself there. 2069506f1d07SSam Ravnborg 2070506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2071506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2072506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2073506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2074506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2075506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2076506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2077506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2078506f1d07SSam Ravnborg 2079ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2080ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2081ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2082ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2083ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2084ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2085ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2086330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2087ceefccc9SH. Peter Anvin for more details about crash dumps. 2088506f1d07SSam Ravnborg 2089506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2090506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2091506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2092506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2093506f1d07SSam Ravnborg is present because there are users out there who continue to use 2094506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2095506f1d07SSam Ravnborg line. 2096506f1d07SSam Ravnborg 2097506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2098506f1d07SSam Ravnborg 2099506f1d07SSam Ravnborgconfig RELOCATABLE 210026717808SH. Peter Anvin bool "Build a relocatable kernel" 210126717808SH. Peter Anvin default y 2102a7f7f624SMasahiro Yamada help 2103506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2104506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2105506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2106506f1d07SSam Ravnborg but are discarded at runtime. 2107506f1d07SSam Ravnborg 2108506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2109506f1d07SSam Ravnborg must live at a different physical address than the primary 2110506f1d07SSam Ravnborg kernel. 2111506f1d07SSam Ravnborg 2112506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2113506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 21148ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2115506f1d07SSam Ravnborg 21168ab3820fSKees Cookconfig RANDOMIZE_BASE 2117e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21188ab3820fSKees Cook depends on RELOCATABLE 21196807c846SIngo Molnar default y 2120a7f7f624SMasahiro Yamada help 2121e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2122e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2123e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2124e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2125e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2126e8581e3dSBaoquan He code internals. 2127e8581e3dSBaoquan He 2128ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2129ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2130ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2131ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2132ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2133ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2134ed9f007eSKees Cook 2135ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2136ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2137ed9f007eSKees Cook 512MB (8 bits of entropy). 21388ab3820fSKees Cook 2139a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2140e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2141e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2142ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2143ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2144ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2145ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2146ed9f007eSKees Cook theoretically possible, but the implementations are further 2147ed9f007eSKees Cook limited due to memory layouts. 2148e8581e3dSBaoquan He 21496807c846SIngo Molnar If unsure, say Y. 2150da2b6fb9SKees Cook 21518ab3820fSKees Cook# Relocation on x86 needs some additional build support 2152845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2153845adf72SH. Peter Anvin def_bool y 21548ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2155845adf72SH. Peter Anvin 2156506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2157a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 21588ab3820fSKees Cook default "0x200000" 2159a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2160a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2161a7f7f624SMasahiro Yamada help 2162506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2163506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2164506f1d07SSam Ravnborg address which meets above alignment restriction. 2165506f1d07SSam Ravnborg 2166506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2167506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2168506f1d07SSam Ravnborg address aligned to above value and run from there. 2169506f1d07SSam Ravnborg 2170506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2171506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2172506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2173506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2174506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2175506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2176506f1d07SSam Ravnborg above alignment restrictions. 2177506f1d07SSam Ravnborg 2178a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2179a0215061SKees Cook this value must be a multiple of 0x200000. 2180a0215061SKees Cook 2181506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2182506f1d07SSam Ravnborg 2183eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2184eedb92abSKirill A. Shutemov bool 2185a7f7f624SMasahiro Yamada help 2186eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2187eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2188eedb92abSKirill A. Shutemov 21890483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 21900483e1faSThomas Garnier bool "Randomize the kernel memory sections" 21910483e1faSThomas Garnier depends on X86_64 21920483e1faSThomas Garnier depends on RANDOMIZE_BASE 2193eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 21940483e1faSThomas Garnier default RANDOMIZE_BASE 2195a7f7f624SMasahiro Yamada help 21960483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 21970483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 21980483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 21990483e1faSThomas Garnier 22000483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 22010483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 22020483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 22030483e1faSThomas Garnier addresses for each memory section. 22040483e1faSThomas Garnier 22056807c846SIngo Molnar If unsure, say Y. 22060483e1faSThomas Garnier 220790397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 220890397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 220990397a41SThomas Garnier depends on RANDOMIZE_MEMORY 221090397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 221190397a41SThomas Garnier default "0x0" 221290397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 221390397a41SThomas Garnier range 0x0 0x40 2214a7f7f624SMasahiro Yamada help 221590397a41SThomas Garnier Define the padding in terabytes added to the existing physical 221690397a41SThomas Garnier memory size during kernel memory randomization. It is useful 221790397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 221890397a41SThomas Garnier address randomization. 221990397a41SThomas Garnier 222090397a41SThomas Garnier If unsure, leave at the default value. 222190397a41SThomas Garnier 22226449dcb0SKirill A. Shutemovconfig ADDRESS_MASKING 22236449dcb0SKirill A. Shutemov bool "Linear Address Masking support" 22246449dcb0SKirill A. Shutemov depends on X86_64 22253267cb6dSPawan Gupta depends on COMPILE_TEST || !CPU_MITIGATIONS # wait for LASS 22266449dcb0SKirill A. Shutemov help 22276449dcb0SKirill A. Shutemov Linear Address Masking (LAM) modifies the checking that is applied 22286449dcb0SKirill A. Shutemov to 64-bit linear addresses, allowing software to use of the 22296449dcb0SKirill A. Shutemov untranslated address bits for metadata. 22306449dcb0SKirill A. Shutemov 22316449dcb0SKirill A. Shutemov The capability can be used for efficient address sanitizers (ASAN) 22326449dcb0SKirill A. Shutemov implementation and for optimizations in JITs. 22336449dcb0SKirill A. Shutemov 2234506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2235bebd024eSThomas Gleixner def_bool y 223640b31360SStephen Rothwell depends on SMP 2237506f1d07SSam Ravnborg 2238506f1d07SSam Ravnborgconfig COMPAT_VDSO 2239b0b49f26SAndy Lutomirski def_bool n 2240b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2241953fee1dSIngo Molnar depends on COMPAT_32 2242a7f7f624SMasahiro Yamada help 2243b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2244b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2245b0b49f26SAndy Lutomirski indicated in its segment table. 2246e84446deSRandy Dunlap 2247b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2248b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2249b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2250b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2251b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2252506f1d07SSam Ravnborg 2253b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2254b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2255b0b49f26SAndy Lutomirski 2256b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2257b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2258b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2259b0b49f26SAndy Lutomirski 2260b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2261b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2262506f1d07SSam Ravnborg 22633dc33bd3SKees Cookchoice 22643dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 22653dc33bd3SKees Cook depends on X86_64 2266625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 22673dc33bd3SKees Cook help 22683dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 22693dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 22703dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 22713dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 22723dc33bd3SKees Cook 22733dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2274bf00745eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. Emulate mode 2275bf00745eSAndy Lutomirski is deprecated and can only be enabled using the kernel command 2276bf00745eSAndy Lutomirski line. 22773dc33bd3SKees Cook 22783dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 22793dc33bd3SKees Cook static binaries, you can say None without a performance penalty 22803dc33bd3SKees Cook to improve security. 22813dc33bd3SKees Cook 2282bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 22833dc33bd3SKees Cook 2284bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2285bd49e16eSAndy Lutomirski bool "Emulate execution only" 2286bd49e16eSAndy Lutomirski help 2287bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2288bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2289bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2290bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2291bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2292bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2293bd49e16eSAndy Lutomirski buffer. 22943dc33bd3SKees Cook 22953dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 22963dc33bd3SKees Cook bool "None" 22973dc33bd3SKees Cook help 22983dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 22993dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23003dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23013dc33bd3SKees Cook will be reported to dmesg, so that either old or 23023dc33bd3SKees Cook malicious userspace programs can be identified. 23033dc33bd3SKees Cook 23043dc33bd3SKees Cookendchoice 23053dc33bd3SKees Cook 2306516cbf37STim Birdconfig CMDLINE_BOOL 2307516cbf37STim Bird bool "Built-in kernel command line" 2308a7f7f624SMasahiro Yamada help 2309516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2310516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2311516cbf37STim Bird necessary or convenient to provide some or all of the 2312516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2313516cbf37STim Bird to not rely on the boot loader to provide them.) 2314516cbf37STim Bird 2315516cbf37STim Bird To compile command line arguments into the kernel, 2316516cbf37STim Bird set this option to 'Y', then fill in the 231769711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2318516cbf37STim Bird 2319516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2320516cbf37STim Bird should leave this option set to 'N'. 2321516cbf37STim Bird 2322516cbf37STim Birdconfig CMDLINE 2323516cbf37STim Bird string "Built-in kernel command string" 2324516cbf37STim Bird depends on CMDLINE_BOOL 2325516cbf37STim Bird default "" 2326a7f7f624SMasahiro Yamada help 2327516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2328516cbf37STim Bird image and used at boot time. If the boot loader provides a 2329516cbf37STim Bird command line at boot time, it is appended to this string to 2330516cbf37STim Bird form the full kernel command line, when the system boots. 2331516cbf37STim Bird 2332516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2333516cbf37STim Bird change this behavior. 2334516cbf37STim Bird 2335516cbf37STim Bird In most cases, the command line (whether built-in or provided 2336516cbf37STim Bird by the boot loader) should specify the device for the root 2337516cbf37STim Bird file system. 2338516cbf37STim Bird 2339516cbf37STim Birdconfig CMDLINE_OVERRIDE 2340516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2341645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2342a7f7f624SMasahiro Yamada help 2343516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2344516cbf37STim Bird command line, and use ONLY the built-in command line. 2345516cbf37STim Bird 2346516cbf37STim Bird This is used to work around broken boot loaders. This should 2347516cbf37STim Bird be set to 'N' under normal conditions. 2348516cbf37STim Bird 2349a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2350a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2351a5b9e5a2SAndy Lutomirski default y 2352a7f7f624SMasahiro Yamada help 2353a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2354a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2355a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2356a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2357a5b9e5a2SAndy Lutomirski threading libraries. 2358a5b9e5a2SAndy Lutomirski 2359a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2360a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2361a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2362a5b9e5a2SAndy Lutomirski 2363a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2364a5b9e5a2SAndy Lutomirski 23653aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE 23663aac3ebeSThomas Gleixner bool "Enforce strict size checking for sigaltstack" 23673aac3ebeSThomas Gleixner depends on DYNAMIC_SIGFRAME 23683aac3ebeSThomas Gleixner help 23693aac3ebeSThomas Gleixner For historical reasons MINSIGSTKSZ is a constant which became 23703aac3ebeSThomas Gleixner already too small with AVX512 support. Add a mechanism to 23713aac3ebeSThomas Gleixner enforce strict checking of the sigaltstack size against the 23723aac3ebeSThomas Gleixner real size of the FPU frame. This option enables the check 23733aac3ebeSThomas Gleixner by default. It can also be controlled via the kernel command 23743aac3ebeSThomas Gleixner line option 'strict_sas_size' independent of this config 23753aac3ebeSThomas Gleixner switch. Enabling it might break existing applications which 23763aac3ebeSThomas Gleixner allocate a too small sigaltstack but 'work' because they 23773aac3ebeSThomas Gleixner never get a signal delivered. 23783aac3ebeSThomas Gleixner 23793aac3ebeSThomas Gleixner Say 'N' unless you want to really enforce this check. 23803aac3ebeSThomas Gleixner 2381d6f635bcSKees Cookconfig CFI_AUTO_DEFAULT 2382d6f635bcSKees Cook bool "Attempt to use FineIBT by default at boot time" 2383d6f635bcSKees Cook depends on FINEIBT 2384d6f635bcSKees Cook default y 2385d6f635bcSKees Cook help 2386d6f635bcSKees Cook Attempt to use FineIBT by default at boot time. If enabled, 2387d6f635bcSKees Cook this is the same as booting with "cfi=auto". If disabled, 2388d6f635bcSKees Cook this is the same as booting with "cfi=kcfi". 2389d6f635bcSKees Cook 2390b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2391b700e7f0SSeth Jennings 2392350afa8aSRavi Bangoriaconfig X86_BUS_LOCK_DETECT 2393350afa8aSRavi Bangoria bool "Split Lock Detect and Bus Lock Detect support" 2394408eb741SRavi Bangoria depends on CPU_SUP_INTEL || CPU_SUP_AMD 2395350afa8aSRavi Bangoria default y 2396350afa8aSRavi Bangoria help 2397350afa8aSRavi Bangoria Enable Split Lock Detect and Bus Lock Detect functionalities. 2398350afa8aSRavi Bangoria See <file:Documentation/arch/x86/buslock.rst> for more information. 2399350afa8aSRavi Bangoria 2400506f1d07SSam Ravnborgendmenu 2401506f1d07SSam Ravnborg 24021ca3683cSUros Bizjakconfig CC_HAS_NAMED_AS 240347ff30ccSUros Bizjak def_bool $(success,echo 'int __seg_fs fs; int __seg_gs gs;' | $(CC) -x c - -S -o /dev/null) 240447ff30ccSUros Bizjak depends on CC_IS_GCC 24051ca3683cSUros Bizjak 24069ebe5500SUros Bizjakconfig CC_HAS_NAMED_AS_FIXED_SANITIZERS 2407f61f02d1SUros Bizjak def_bool CC_IS_GCC && GCC_VERSION >= 130300 24081ca3683cSUros Bizjak 24091ca3683cSUros Bizjakconfig USE_X86_SEG_SUPPORT 24101ca3683cSUros Bizjak def_bool y 2411e29aad08SUros Bizjak depends on CC_HAS_NAMED_AS 2412e29aad08SUros Bizjak # 24139ebe5500SUros Bizjak # -fsanitize=kernel-address (KASAN) and -fsanitize=thread 24149ebe5500SUros Bizjak # (KCSAN) are incompatible with named address spaces with 24159ebe5500SUros Bizjak # GCC < 13.3 - see GCC PR sanitizer/111736. 2416e29aad08SUros Bizjak # 24179ebe5500SUros Bizjak depends on !(KASAN || KCSAN) || CC_HAS_NAMED_AS_FIXED_SANITIZERS 24181ca3683cSUros Bizjak 2419f43b9876SPeter Zijlstraconfig CC_HAS_SLS 2420f43b9876SPeter Zijlstra def_bool $(cc-option,-mharden-sls=all) 2421f43b9876SPeter Zijlstra 2422f43b9876SPeter Zijlstraconfig CC_HAS_RETURN_THUNK 2423f43b9876SPeter Zijlstra def_bool $(cc-option,-mfunction-return=thunk-extern) 2424f43b9876SPeter Zijlstra 2425bea75b33SThomas Gleixnerconfig CC_HAS_ENTRY_PADDING 2426bea75b33SThomas Gleixner def_bool $(cc-option,-fpatchable-function-entry=16,16) 2427bea75b33SThomas Gleixner 2428bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_CFI 2429bea75b33SThomas Gleixner int 2430bea75b33SThomas Gleixner default 59 if FUNCTION_ALIGNMENT_64B 2431bea75b33SThomas Gleixner default 27 if FUNCTION_ALIGNMENT_32B 2432bea75b33SThomas Gleixner default 11 if FUNCTION_ALIGNMENT_16B 2433bea75b33SThomas Gleixner default 3 if FUNCTION_ALIGNMENT_8B 2434bea75b33SThomas Gleixner default 0 2435bea75b33SThomas Gleixner 2436bea75b33SThomas Gleixner# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG 2437bea75b33SThomas Gleixner# except Kconfig can't do arithmetic :/ 2438bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_BYTES 2439bea75b33SThomas Gleixner int 2440bea75b33SThomas Gleixner default FUNCTION_PADDING_CFI if CFI_CLANG 2441bea75b33SThomas Gleixner default FUNCTION_ALIGNMENT 2442bea75b33SThomas Gleixner 2443931ab636SPeter Zijlstraconfig CALL_PADDING 2444931ab636SPeter Zijlstra def_bool n 2445931ab636SPeter Zijlstra depends on CC_HAS_ENTRY_PADDING && OBJTOOL 2446931ab636SPeter Zijlstra select FUNCTION_ALIGNMENT_16B 2447931ab636SPeter Zijlstra 2448931ab636SPeter Zijlstraconfig FINEIBT 2449931ab636SPeter Zijlstra def_bool y 2450aefb2f2eSBreno Leitao depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE 2451931ab636SPeter Zijlstra select CALL_PADDING 2452931ab636SPeter Zijlstra 24538f7c0d8bSThomas Gleixnerconfig HAVE_CALL_THUNKS 24548f7c0d8bSThomas Gleixner def_bool y 24550911b8c5SBreno Leitao depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL 24568f7c0d8bSThomas Gleixner 24578f7c0d8bSThomas Gleixnerconfig CALL_THUNKS 24588f7c0d8bSThomas Gleixner def_bool n 2459931ab636SPeter Zijlstra select CALL_PADDING 24608f7c0d8bSThomas Gleixner 2461b341b20dSPeter Zijlstraconfig PREFIX_SYMBOLS 2462b341b20dSPeter Zijlstra def_bool y 2463931ab636SPeter Zijlstra depends on CALL_PADDING && !CFI_CLANG 2464b341b20dSPeter Zijlstra 2465fe42754bSSean Christophersonmenuconfig CPU_MITIGATIONS 2466fe42754bSSean Christopherson bool "Mitigations for CPU vulnerabilities" 2467f43b9876SPeter Zijlstra default y 2468f43b9876SPeter Zijlstra help 2469fe42754bSSean Christopherson Say Y here to enable options which enable mitigations for hardware 2470fe42754bSSean Christopherson vulnerabilities (usually related to speculative execution). 2471ce0abef6SSean Christopherson Mitigations can be disabled or restricted to SMT systems at runtime 2472ce0abef6SSean Christopherson via the "mitigations" kernel parameter. 2473f43b9876SPeter Zijlstra 2474ce0abef6SSean Christopherson If you say N, all mitigations will be disabled. This CANNOT be 2475ce0abef6SSean Christopherson overridden at runtime. 2476ce0abef6SSean Christopherson 2477ce0abef6SSean Christopherson Say 'Y', unless you really know what you are doing. 2478f43b9876SPeter Zijlstra 2479fe42754bSSean Christophersonif CPU_MITIGATIONS 2480f43b9876SPeter Zijlstra 2481ea4654e0SBreno Leitaoconfig MITIGATION_PAGE_TABLE_ISOLATION 2482f43b9876SPeter Zijlstra bool "Remove the kernel mapping in user mode" 2483f43b9876SPeter Zijlstra default y 2484f43b9876SPeter Zijlstra depends on (X86_64 || X86_PAE) 2485f43b9876SPeter Zijlstra help 2486f43b9876SPeter Zijlstra This feature reduces the number of hardware side channels by 2487f43b9876SPeter Zijlstra ensuring that the majority of kernel addresses are not mapped 2488f43b9876SPeter Zijlstra into userspace. 2489f43b9876SPeter Zijlstra 2490ff61f079SJonathan Corbet See Documentation/arch/x86/pti.rst for more details. 2491f43b9876SPeter Zijlstra 2492aefb2f2eSBreno Leitaoconfig MITIGATION_RETPOLINE 2493f43b9876SPeter Zijlstra bool "Avoid speculative indirect branches in kernel" 2494f43b9876SPeter Zijlstra select OBJTOOL if HAVE_OBJTOOL 2495f43b9876SPeter Zijlstra default y 2496f43b9876SPeter Zijlstra help 2497f43b9876SPeter Zijlstra Compile kernel with the retpoline compiler options to guard against 2498f43b9876SPeter Zijlstra kernel-to-user data leaks by avoiding speculative indirect 2499f43b9876SPeter Zijlstra branches. Requires a compiler with -mindirect-branch=thunk-extern 2500f43b9876SPeter Zijlstra support for full protection. The kernel may run slower. 2501f43b9876SPeter Zijlstra 25020911b8c5SBreno Leitaoconfig MITIGATION_RETHUNK 2503f43b9876SPeter Zijlstra bool "Enable return-thunks" 2504aefb2f2eSBreno Leitao depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK 2505f43b9876SPeter Zijlstra select OBJTOOL if HAVE_OBJTOOL 2506b648ab48SBen Hutchings default y if X86_64 2507f43b9876SPeter Zijlstra help 2508f43b9876SPeter Zijlstra Compile the kernel with the return-thunks compiler option to guard 2509f43b9876SPeter Zijlstra against kernel-to-user data leaks by avoiding return speculation. 2510f43b9876SPeter Zijlstra Requires a compiler with -mfunction-return=thunk-extern 2511f43b9876SPeter Zijlstra support for full protection. The kernel may run slower. 2512f43b9876SPeter Zijlstra 2513ac61d439SBreno Leitaoconfig MITIGATION_UNRET_ENTRY 2514f43b9876SPeter Zijlstra bool "Enable UNRET on kernel entry" 25150911b8c5SBreno Leitao depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64 2516f43b9876SPeter Zijlstra default y 2517f43b9876SPeter Zijlstra help 2518f43b9876SPeter Zijlstra Compile the kernel with support for the retbleed=unret mitigation. 2519f43b9876SPeter Zijlstra 25205fa31af3SBreno Leitaoconfig MITIGATION_CALL_DEPTH_TRACKING 252180e4c1cdSThomas Gleixner bool "Mitigate RSB underflow with call depth tracking" 252280e4c1cdSThomas Gleixner depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS 252380e4c1cdSThomas Gleixner select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 252480e4c1cdSThomas Gleixner select CALL_THUNKS 252580e4c1cdSThomas Gleixner default y 252680e4c1cdSThomas Gleixner help 252780e4c1cdSThomas Gleixner Compile the kernel with call depth tracking to mitigate the Intel 252886e39b94SBreno Leitao SKL Return-Stack-Buffer (RSB) underflow issue. The mitigation is off 252986e39b94SBreno Leitao by default and needs to be enabled on the kernel command line via the 253086e39b94SBreno Leitao retbleed=stuff option. For non-affected systems the overhead of this 253186e39b94SBreno Leitao option is marginal as the call depth tracking is using run-time 253286e39b94SBreno Leitao generated call thunks in a compiler generated padding area and call 253386e39b94SBreno Leitao patching. This increases text size by ~5%. For non affected systems 253486e39b94SBreno Leitao this space is unused. On affected SKL systems this results in a 253586e39b94SBreno Leitao significant performance gain over the IBRS mitigation. 253680e4c1cdSThomas Gleixner 2537e81dc127SThomas Gleixnerconfig CALL_THUNKS_DEBUG 2538e81dc127SThomas Gleixner bool "Enable call thunks and call depth tracking debugging" 25395fa31af3SBreno Leitao depends on MITIGATION_CALL_DEPTH_TRACKING 2540e81dc127SThomas Gleixner select FUNCTION_ALIGNMENT_32B 2541e81dc127SThomas Gleixner default n 2542e81dc127SThomas Gleixner help 2543e81dc127SThomas Gleixner Enable call/ret counters for imbalance detection and build in 2544e81dc127SThomas Gleixner a noisy dmesg about callthunks generation and call patching for 2545e81dc127SThomas Gleixner trouble shooting. The debug prints need to be enabled on the 2546e81dc127SThomas Gleixner kernel command line with 'debug-callthunks'. 254754628de6SRandy Dunlap Only enable this when you are debugging call thunks as this 254854628de6SRandy Dunlap creates a noticeable runtime overhead. If unsure say N. 254980e4c1cdSThomas Gleixner 2550e0b8fcfaSBreno Leitaoconfig MITIGATION_IBPB_ENTRY 2551f43b9876SPeter Zijlstra bool "Enable IBPB on kernel entry" 2552b648ab48SBen Hutchings depends on CPU_SUP_AMD && X86_64 2553f43b9876SPeter Zijlstra default y 2554f43b9876SPeter Zijlstra help 2555318e8c33SPatrick Bellasi Compile the kernel with support for the retbleed=ibpb and 2556318e8c33SPatrick Bellasi spec_rstack_overflow={ibpb,ibpb-vmexit} mitigations. 2557f43b9876SPeter Zijlstra 25581da8d217SBreno Leitaoconfig MITIGATION_IBRS_ENTRY 2559f43b9876SPeter Zijlstra bool "Enable IBRS on kernel entry" 2560b648ab48SBen Hutchings depends on CPU_SUP_INTEL && X86_64 2561f43b9876SPeter Zijlstra default y 2562f43b9876SPeter Zijlstra help 2563f43b9876SPeter Zijlstra Compile the kernel with support for the spectre_v2=ibrs mitigation. 2564f43b9876SPeter Zijlstra This mitigates both spectre_v2 and retbleed at great cost to 2565f43b9876SPeter Zijlstra performance. 2566f43b9876SPeter Zijlstra 2567a033eec9SBreno Leitaoconfig MITIGATION_SRSO 2568fb3bd914SBorislav Petkov (AMD) bool "Mitigate speculative RAS overflow on AMD" 25690911b8c5SBreno Leitao depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK 2570fb3bd914SBorislav Petkov (AMD) default y 2571fb3bd914SBorislav Petkov (AMD) help 2572fb3bd914SBorislav Petkov (AMD) Enable the SRSO mitigation needed on AMD Zen1-4 machines. 2573fb3bd914SBorislav Petkov (AMD) 25747b75782fSBreno Leitaoconfig MITIGATION_SLS 2575f43b9876SPeter Zijlstra bool "Mitigate Straight-Line-Speculation" 2576f43b9876SPeter Zijlstra depends on CC_HAS_SLS && X86_64 2577f43b9876SPeter Zijlstra select OBJTOOL if HAVE_OBJTOOL 2578f43b9876SPeter Zijlstra default n 2579f43b9876SPeter Zijlstra help 2580f43b9876SPeter Zijlstra Compile the kernel with straight-line-speculation options to guard 2581f43b9876SPeter Zijlstra against straight line speculation. The kernel image might be slightly 2582f43b9876SPeter Zijlstra larger. 2583f43b9876SPeter Zijlstra 2584225f2bd0SBreno Leitaoconfig MITIGATION_GDS 2585225f2bd0SBreno Leitao bool "Mitigate Gather Data Sampling" 2586225f2bd0SBreno Leitao depends on CPU_SUP_INTEL 2587225f2bd0SBreno Leitao default y 2588225f2bd0SBreno Leitao help 2589225f2bd0SBreno Leitao Enable mitigation for Gather Data Sampling (GDS). GDS is a hardware 2590225f2bd0SBreno Leitao vulnerability which allows unprivileged speculative access to data 2591225f2bd0SBreno Leitao which was previously stored in vector registers. The attacker uses gather 2592225f2bd0SBreno Leitao instructions to infer the stale vector register data. 2593225f2bd0SBreno Leitao 25948076fcdeSPawan Guptaconfig MITIGATION_RFDS 25958076fcdeSPawan Gupta bool "RFDS Mitigation" 25968076fcdeSPawan Gupta depends on CPU_SUP_INTEL 25978076fcdeSPawan Gupta default y 25988076fcdeSPawan Gupta help 25998076fcdeSPawan Gupta Enable mitigation for Register File Data Sampling (RFDS) by default. 26008076fcdeSPawan Gupta RFDS is a hardware vulnerability which affects Intel Atom CPUs. It 26018076fcdeSPawan Gupta allows unprivileged speculative access to stale data previously 26028076fcdeSPawan Gupta stored in floating point, vector and integer registers. 26038076fcdeSPawan Gupta See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst> 26048076fcdeSPawan Gupta 26054f511739SJosh Poimboeufconfig MITIGATION_SPECTRE_BHI 26064f511739SJosh Poimboeuf bool "Mitigate Spectre-BHB (Branch History Injection)" 2607ec9404e4SPawan Gupta depends on CPU_SUP_INTEL 26084f511739SJosh Poimboeuf default y 2609ec9404e4SPawan Gupta help 2610ec9404e4SPawan Gupta Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks 2611ec9404e4SPawan Gupta where the branch history buffer is poisoned to speculatively steer 2612ec9404e4SPawan Gupta indirect branches. 2613ec9404e4SPawan Gupta See <file:Documentation/admin-guide/hw-vuln/spectre.rst> 2614ec9404e4SPawan Gupta 261594045568SBreno Leitaoconfig MITIGATION_MDS 261694045568SBreno Leitao bool "Mitigate Microarchitectural Data Sampling (MDS) hardware bug" 261794045568SBreno Leitao depends on CPU_SUP_INTEL 261894045568SBreno Leitao default y 261994045568SBreno Leitao help 262094045568SBreno Leitao Enable mitigation for Microarchitectural Data Sampling (MDS). MDS is 262194045568SBreno Leitao a hardware vulnerability which allows unprivileged speculative access 262294045568SBreno Leitao to data which is available in various CPU internal buffers. 262394045568SBreno Leitao See also <file:Documentation/admin-guide/hw-vuln/mds.rst> 2624b8da0b33SBreno Leitao 2625b8da0b33SBreno Leitaoconfig MITIGATION_TAA 2626b8da0b33SBreno Leitao bool "Mitigate TSX Asynchronous Abort (TAA) hardware bug" 2627b8da0b33SBreno Leitao depends on CPU_SUP_INTEL 2628b8da0b33SBreno Leitao default y 2629b8da0b33SBreno Leitao help 2630b8da0b33SBreno Leitao Enable mitigation for TSX Asynchronous Abort (TAA). TAA is a hardware 2631b8da0b33SBreno Leitao vulnerability that allows unprivileged speculative access to data 2632b8da0b33SBreno Leitao which is available in various CPU internal buffers by using 2633b8da0b33SBreno Leitao asynchronous aborts within an Intel TSX transactional region. 2634b8da0b33SBreno Leitao See also <file:Documentation/admin-guide/hw-vuln/tsx_async_abort.rst> 2635163f9fe6SBreno Leitao 2636163f9fe6SBreno Leitaoconfig MITIGATION_MMIO_STALE_DATA 2637163f9fe6SBreno Leitao bool "Mitigate MMIO Stale Data hardware bug" 2638163f9fe6SBreno Leitao depends on CPU_SUP_INTEL 2639163f9fe6SBreno Leitao default y 2640163f9fe6SBreno Leitao help 2641163f9fe6SBreno Leitao Enable mitigation for MMIO Stale Data hardware bugs. Processor MMIO 2642163f9fe6SBreno Leitao Stale Data Vulnerabilities are a class of memory-mapped I/O (MMIO) 2643163f9fe6SBreno Leitao vulnerabilities that can expose data. The vulnerabilities require the 2644163f9fe6SBreno Leitao attacker to have access to MMIO. 2645163f9fe6SBreno Leitao See also 2646163f9fe6SBreno Leitao <file:Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst> 26473a4ee4ffSBreno Leitao 26483a4ee4ffSBreno Leitaoconfig MITIGATION_L1TF 26493a4ee4ffSBreno Leitao bool "Mitigate L1 Terminal Fault (L1TF) hardware bug" 26503a4ee4ffSBreno Leitao depends on CPU_SUP_INTEL 26513a4ee4ffSBreno Leitao default y 26523a4ee4ffSBreno Leitao help 26533a4ee4ffSBreno Leitao Mitigate L1 Terminal Fault (L1TF) hardware bug. L1 Terminal Fault is a 26543a4ee4ffSBreno Leitao hardware vulnerability which allows unprivileged speculative access to data 26553a4ee4ffSBreno Leitao available in the Level 1 Data Cache. 26563a4ee4ffSBreno Leitao See <file:Documentation/admin-guide/hw-vuln/l1tf.rst 2657894e2885SBreno Leitao 2658894e2885SBreno Leitaoconfig MITIGATION_RETBLEED 2659894e2885SBreno Leitao bool "Mitigate RETBleed hardware bug" 2660894e2885SBreno Leitao depends on (CPU_SUP_INTEL && MITIGATION_SPECTRE_V2) || MITIGATION_UNRET_ENTRY || MITIGATION_IBPB_ENTRY 2661894e2885SBreno Leitao default y 2662894e2885SBreno Leitao help 2663894e2885SBreno Leitao Enable mitigation for RETBleed (Arbitrary Speculative Code Execution 2664894e2885SBreno Leitao with Return Instructions) vulnerability. RETBleed is a speculative 2665894e2885SBreno Leitao execution attack which takes advantage of microarchitectural behavior 2666894e2885SBreno Leitao in many modern microprocessors, similar to Spectre v2. An 2667894e2885SBreno Leitao unprivileged attacker can use these flaws to bypass conventional 2668894e2885SBreno Leitao memory security restrictions to gain read access to privileged memory 2669894e2885SBreno Leitao that would otherwise be inaccessible. 2670ca01c0d8SBreno Leitao 2671ca01c0d8SBreno Leitaoconfig MITIGATION_SPECTRE_V1 2672ca01c0d8SBreno Leitao bool "Mitigate SPECTRE V1 hardware bug" 2673ca01c0d8SBreno Leitao default y 2674ca01c0d8SBreno Leitao help 2675ca01c0d8SBreno Leitao Enable mitigation for Spectre V1 (Bounds Check Bypass). Spectre V1 is a 2676ca01c0d8SBreno Leitao class of side channel attacks that takes advantage of speculative 2677ca01c0d8SBreno Leitao execution that bypasses conditional branch instructions used for 2678ca01c0d8SBreno Leitao memory access bounds check. 2679ca01c0d8SBreno Leitao See also <file:Documentation/admin-guide/hw-vuln/spectre.rst> 2680a0b02e3fSBreno Leitao 268172c70f48SBreno Leitaoconfig MITIGATION_SPECTRE_V2 268272c70f48SBreno Leitao bool "Mitigate SPECTRE V2 hardware bug" 268372c70f48SBreno Leitao default y 268472c70f48SBreno Leitao help 268572c70f48SBreno Leitao Enable mitigation for Spectre V2 (Branch Target Injection). Spectre 268672c70f48SBreno Leitao V2 is a class of side channel attacks that takes advantage of 268772c70f48SBreno Leitao indirect branch predictors inside the processor. In Spectre variant 2 268872c70f48SBreno Leitao attacks, the attacker can steer speculative indirect branches in the 268972c70f48SBreno Leitao victim to gadget code by poisoning the branch target buffer of a CPU 269072c70f48SBreno Leitao used for predicting indirect branch addresses. 269172c70f48SBreno Leitao See also <file:Documentation/admin-guide/hw-vuln/spectre.rst> 269272c70f48SBreno Leitao 2693a0b02e3fSBreno Leitaoconfig MITIGATION_SRBDS 2694a0b02e3fSBreno Leitao bool "Mitigate Special Register Buffer Data Sampling (SRBDS) hardware bug" 2695a0b02e3fSBreno Leitao depends on CPU_SUP_INTEL 2696a0b02e3fSBreno Leitao default y 2697a0b02e3fSBreno Leitao help 2698a0b02e3fSBreno Leitao Enable mitigation for Special Register Buffer Data Sampling (SRBDS). 2699a0b02e3fSBreno Leitao SRBDS is a hardware vulnerability that allows Microarchitectural Data 2700a0b02e3fSBreno Leitao Sampling (MDS) techniques to infer values returned from special 2701a0b02e3fSBreno Leitao register accesses. An unprivileged user can extract values returned 2702a0b02e3fSBreno Leitao from RDRAND and RDSEED executed on another core or sibling thread 2703a0b02e3fSBreno Leitao using MDS techniques. 2704a0b02e3fSBreno Leitao See also 2705a0b02e3fSBreno Leitao <file:Documentation/admin-guide/hw-vuln/special-register-buffer-data-sampling.rst> 2706b908cdabSBreno Leitao 2707b908cdabSBreno Leitaoconfig MITIGATION_SSB 2708b908cdabSBreno Leitao bool "Mitigate Speculative Store Bypass (SSB) hardware bug" 2709b908cdabSBreno Leitao default y 2710b908cdabSBreno Leitao help 2711b908cdabSBreno Leitao Enable mitigation for Speculative Store Bypass (SSB). SSB is a 2712b908cdabSBreno Leitao hardware security vulnerability and its exploitation takes advantage 2713b908cdabSBreno Leitao of speculative execution in a similar way to the Meltdown and Spectre 2714b908cdabSBreno Leitao security vulnerabilities. 2715b908cdabSBreno Leitao 2716f43b9876SPeter Zijlstraendif 2717f43b9876SPeter Zijlstra 27183072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 27193072e413SMichal Hocko def_bool y 27205c11f00bSDavid Hildenbrand depends on ARCH_ENABLE_MEMORY_HOTPLUG 27213072e413SMichal Hocko 2722da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2723e279b6c1SSam Ravnborg 2724e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 27253c2362e6SHarvey Harrison def_bool y 272644556530SZhimin Gu depends on HIBERNATION 2727e279b6c1SSam Ravnborg 2728e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2729e279b6c1SSam Ravnborg 2730e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2731e279b6c1SSam Ravnborg 2732a6b68076SAndi Kleenconfig X86_APM_BOOT 27336fc108a0SJan Beulich def_bool y 2734282e5aabSPaul Bolle depends on APM 2735a6b68076SAndi Kleen 2736e279b6c1SSam Ravnborgmenuconfig APM 2737e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2738efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2739a7f7f624SMasahiro Yamada help 2740e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2741e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2742e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2743e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2744e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2745e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2746e279b6c1SSam Ravnborg 2747e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2748e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2749e279b6c1SSam Ravnborg 2750e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2751e279b6c1SSam Ravnborg machines with more than one CPU. 2752e279b6c1SSam Ravnborg 2753e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2754151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 27552dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2756e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2757e279b6c1SSam Ravnborg 2758e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2759e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2760e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2761e279b6c1SSam Ravnborg 2762e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2763e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2764e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2765e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2766e279b6c1SSam Ravnborg 2767e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2768e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2769e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2770e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2771e279b6c1SSam Ravnborg APM in your BIOS). 2772e279b6c1SSam Ravnborg 2773e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2774e279b6c1SSam Ravnborg "weird" problems: 2775e279b6c1SSam Ravnborg 2776e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2777e279b6c1SSam Ravnborg enabled. 27787987448fSStephen Kitt 2) pass the "idle=poll" option to the kernel 2779e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2780e279b6c1SSam Ravnborg the "no387" option to the kernel 2781e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2782e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2783e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2784e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2785e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2786e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2787e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2788e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2789e279b6c1SSam Ravnborg 11) exchange RAM chips 2790e279b6c1SSam Ravnborg 12) exchange the motherboard. 2791e279b6c1SSam Ravnborg 2792e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2793e279b6c1SSam Ravnborg module will be called apm. 2794e279b6c1SSam Ravnborg 2795e279b6c1SSam Ravnborgif APM 2796e279b6c1SSam Ravnborg 2797e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2798e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2799a7f7f624SMasahiro Yamada help 2800e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2801e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2802e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2803e279b6c1SSam Ravnborg 2804e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2805e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2806a7f7f624SMasahiro Yamada help 2807e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2808e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2809e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2810e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2811e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2812e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2813e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2814e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2815e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2816e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2817e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2818e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2819e279b6c1SSam Ravnborg this feature. 2820e279b6c1SSam Ravnborg 2821e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2822dd8af076SLen Brown depends on CPU_IDLE 2823e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2824a7f7f624SMasahiro Yamada help 2825e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2826e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2827e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2828e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2829e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2830e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2831e279b6c1SSam Ravnborg this option does nothing.) 2832e279b6c1SSam Ravnborg 2833e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2834e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2835a7f7f624SMasahiro Yamada help 2836e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2837e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2838e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2839e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2840e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2841e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2842e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2843e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2844e279b6c1SSam Ravnborg especially if you are using gpm. 2845e279b6c1SSam Ravnborg 2846e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2847e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2848a7f7f624SMasahiro Yamada help 2849e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2850e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2851e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2852e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2853e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2854e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2855e279b6c1SSam Ravnborg 2856e279b6c1SSam Ravnborgendif # APM 2857e279b6c1SSam Ravnborg 2858bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2859e279b6c1SSam Ravnborg 2860e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2861e279b6c1SSam Ravnborg 286227471fdbSAndy Henroidsource "drivers/idle/Kconfig" 286327471fdbSAndy Henroid 2864e279b6c1SSam Ravnborgendmenu 2865e279b6c1SSam Ravnborg 2866e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2867e279b6c1SSam Ravnborg 2868e279b6c1SSam Ravnborgchoice 2869e279b6c1SSam Ravnborg prompt "PCI access mode" 2870efefa6f6SIngo Molnar depends on X86_32 && PCI 2871e279b6c1SSam Ravnborg default PCI_GOANY 2872a7f7f624SMasahiro Yamada help 2873e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2874e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2875e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2876e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2877e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2878e279b6c1SSam Ravnborg 2879e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2880e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2881e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2882e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2883e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2884e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2885e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2886e279b6c1SSam Ravnborg 2887e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2888e279b6c1SSam Ravnborg bool "BIOS" 2889e279b6c1SSam Ravnborg 2890e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2891e279b6c1SSam Ravnborg bool "MMConfig" 2892e279b6c1SSam Ravnborg 2893e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2894e279b6c1SSam Ravnborg bool "Direct" 2895e279b6c1SSam Ravnborg 28963ef0e1f8SAndres Salomonconfig PCI_GOOLPC 289776fb6570SDaniel Drake bool "OLPC XO-1" 28983ef0e1f8SAndres Salomon depends on OLPC 28993ef0e1f8SAndres Salomon 29002bdd1b03SAndres Salomonconfig PCI_GOANY 29012bdd1b03SAndres Salomon bool "Any" 29022bdd1b03SAndres Salomon 2903e279b6c1SSam Ravnborgendchoice 2904e279b6c1SSam Ravnborg 2905e279b6c1SSam Ravnborgconfig PCI_BIOS 29063c2362e6SHarvey Harrison def_bool y 2907efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2908e279b6c1SSam Ravnborg 2909e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2910e279b6c1SSam Ravnborgconfig PCI_DIRECT 29113c2362e6SHarvey Harrison def_bool y 29120aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2913e279b6c1SSam Ravnborg 2914e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2915b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2916b45c9f36SJan Kiszka default y 29174590d98fSAndy Shevchenko depends on PCI && (ACPI || JAILHOUSE_GUEST) 2918b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2919e279b6c1SSam Ravnborg 29203ef0e1f8SAndres Salomonconfig PCI_OLPC 29212bdd1b03SAndres Salomon def_bool y 29222bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 29233ef0e1f8SAndres Salomon 2924b5401a96SAlex Nixonconfig PCI_XEN 2925b5401a96SAlex Nixon def_bool y 2926b5401a96SAlex Nixon depends on PCI && XEN 2927b5401a96SAlex Nixon 29288364e1f8SJan Kiszkaconfig MMCONF_FAM10H 29298364e1f8SJan Kiszka def_bool y 29308364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2931e279b6c1SSam Ravnborg 29323f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 29336a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 29346ea30386SKees Cook depends on PCI 29353f6ea84aSIra W. Snyder help 29363f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 29373f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 29383f6ea84aSIra W. Snyder not have ACPI. 29393f6ea84aSIra W. Snyder 294064a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 294164a5fed6SBjorn Helgaas is known to be incomplete. 294264a5fed6SBjorn Helgaas 294364a5fed6SBjorn Helgaas You should say N unless you know you need this. 294464a5fed6SBjorn Helgaas 29453a495511SWilliam Breathitt Grayconfig ISA_BUS 294617a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 29473a495511SWilliam Breathitt Gray help 294817a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 294917a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 295017a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 295117a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 295217a2a129SWilliam Breathitt Gray not have an ISA bus. 29533a495511SWilliam Breathitt Gray 29543a495511SWilliam Breathitt Gray If unsure, say N. 29553a495511SWilliam Breathitt Gray 29561c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2957e279b6c1SSam Ravnborgconfig ISA_DMA_API 29581c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 29591c00f016SDavid Rientjes default y 29601c00f016SDavid Rientjes help 29611c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 29621c00f016SDavid Rientjes If unsure, say Y. 2963e279b6c1SSam Ravnborg 296451e68d05SLinus Torvaldsif X86_32 296551e68d05SLinus Torvalds 2966e279b6c1SSam Ravnborgconfig ISA 2967e279b6c1SSam Ravnborg bool "ISA support" 2968a7f7f624SMasahiro Yamada help 2969e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2970e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2971e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2972e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2973e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2974e279b6c1SSam Ravnborg 2975e279b6c1SSam Ravnborgconfig SCx200 2976e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2977a7f7f624SMasahiro Yamada help 2978e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2979e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2980e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2981e279b6c1SSam Ravnborg for other scx200_* drivers. 2982e279b6c1SSam Ravnborg 2983e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2984e279b6c1SSam Ravnborg 2985e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2986e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2987592913ecSJohn Stultz depends on SCx200 2988e279b6c1SSam Ravnborg default y 2989a7f7f624SMasahiro Yamada help 2990e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2991e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2992e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2993e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2994e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2995e279b6c1SSam Ravnborg 29963ef0e1f8SAndres Salomonconfig OLPC 29973ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 299854008979SThomas Gleixner depends on !X86_PAE 29993c554946SAndres Salomon select GPIOLIB 3000dc3119e7SThomas Gleixner select OF 300145bb1674SDaniel Drake select OF_PROMTREE 3002b4e51854SGrant Likely select IRQ_DOMAIN 30030c3d931bSLubomir Rintel select OLPC_EC 3004a7f7f624SMasahiro Yamada help 30053ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 30063ef0e1f8SAndres Salomon XO hardware. 30073ef0e1f8SAndres Salomon 3008a3128588SDaniel Drakeconfig OLPC_XO1_PM 3009a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 3010fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 3011a7f7f624SMasahiro Yamada help 301297c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 3013bf1ebf00SDaniel Drake 3014cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 3015cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 3016cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 3017a7f7f624SMasahiro Yamada help 3018cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 3019cfee9597SDaniel Drake programmable wakeup source. 3020cfee9597SDaniel Drake 30217feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 30227feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 302392e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 3024ed8e47feSRandy Dunlap depends on INPUT=y 3025d8d01a63SDaniel Drake select POWER_SUPPLY 3026a7f7f624SMasahiro Yamada help 30277feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 30287bc74b3dSDaniel Drake - EC-driven system wakeups 30297feda8e9SDaniel Drake - Power button 30307bc74b3dSDaniel Drake - Ebook switch 30312cf2baeaSDaniel Drake - Lid switch 3032e1040ac6SDaniel Drake - AC adapter status updates 3033e1040ac6SDaniel Drake - Battery status updates 30347feda8e9SDaniel Drake 3035a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 3036a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 3037d8d01a63SDaniel Drake depends on OLPC && ACPI 3038d8d01a63SDaniel Drake select POWER_SUPPLY 3039a7f7f624SMasahiro Yamada help 3040a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 3041a0f30f59SDaniel Drake - EC-driven system wakeups 3042a0f30f59SDaniel Drake - AC adapter status updates 3043a0f30f59SDaniel Drake - Battery status updates 3044e279b6c1SSam Ravnborg 3045298c9babSDmitry Torokhovconfig GEODE_COMMON 3046298c9babSDmitry Torokhov bool 3047298c9babSDmitry Torokhov 3048d4f3e350SEd Wildgooseconfig ALIX 3049d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 3050d4f3e350SEd Wildgoose select GPIOLIB 3051298c9babSDmitry Torokhov select GEODE_COMMON 3052a7f7f624SMasahiro Yamada help 3053d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 3054d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 3055d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 3056d4f3e350SEd Wildgoose get added here. 3057d4f3e350SEd Wildgoose 3058d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 3059d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 3060d4f3e350SEd Wildgoose 3061d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 3062d4f3e350SEd Wildgoose 3063da4e3302SPhilip Prindevilleconfig NET5501 3064da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 3065da4e3302SPhilip Prindeville select GPIOLIB 3066298c9babSDmitry Torokhov select GEODE_COMMON 3067a7f7f624SMasahiro Yamada help 3068da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 3069da4e3302SPhilip Prindeville 30703197059aSPhilip A. Prindevilleconfig GEOS 30713197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 30723197059aSPhilip A. Prindeville select GPIOLIB 3073298c9babSDmitry Torokhov select GEODE_COMMON 30743197059aSPhilip A. Prindeville depends on DMI 3075a7f7f624SMasahiro Yamada help 30763197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 30773197059aSPhilip A. Prindeville 30787d029125SVivien Didelotconfig TS5500 30797d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 30807d029125SVivien Didelot depends on MELAN 30817d029125SVivien Didelot select CHECK_SIGNATURE 30827d029125SVivien Didelot select NEW_LEDS 30837d029125SVivien Didelot select LEDS_CLASS 3084a7f7f624SMasahiro Yamada help 30857d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 30867d029125SVivien Didelot 3087e279b6c1SSam Ravnborgendif # X86_32 3088e279b6c1SSam Ravnborg 308923ac4ae8SAndreas Herrmannconfig AMD_NB 3090e279b6c1SSam Ravnborg def_bool y 3091e6e6e5e8SYazen Ghannam depends on AMD_NODE 3092e6e6e5e8SYazen Ghannam 3093e6e6e5e8SYazen Ghannamconfig AMD_NODE 3094e6e6e5e8SYazen Ghannam def_bool y 30950e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 3096e279b6c1SSam Ravnborg 3097e279b6c1SSam Ravnborgendmenu 3098e279b6c1SSam Ravnborg 30991572497cSChristoph Hellwigmenu "Binary Emulations" 3100e279b6c1SSam Ravnborg 3101e279b6c1SSam Ravnborgconfig IA32_EMULATION 3102e279b6c1SSam Ravnborg bool "IA32 Emulation" 3103e279b6c1SSam Ravnborg depends on X86_64 310439f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 3105d1603990SRandy Dunlap select BINFMT_ELF 310639f88911SIngo Molnar select COMPAT_OLD_SIGACTION 3107a7f7f624SMasahiro Yamada help 31085fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 31095fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 31105fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 3111e279b6c1SSam Ravnborg 3112a11e0975SNikolay Borisovconfig IA32_EMULATION_DEFAULT_DISABLED 3113a11e0975SNikolay Borisov bool "IA32 emulation disabled by default" 3114a11e0975SNikolay Borisov default n 3115a11e0975SNikolay Borisov depends on IA32_EMULATION 3116a11e0975SNikolay Borisov help 3117a11e0975SNikolay Borisov Make IA32 emulation disabled by default. This prevents loading 32-bit 3118a11e0975SNikolay Borisov processes and access to 32-bit syscalls. If unsure, leave it to its 3119a11e0975SNikolay Borisov default value. 3120a11e0975SNikolay Borisov 312183a44a4fSMasahiro Yamadaconfig X86_X32_ABI 31226ea30386SKees Cook bool "x32 ABI for 64-bit mode" 31239b54050bSBrian Gerst depends on X86_64 3124aaeed6ecSNathan Chancellor # llvm-objcopy does not convert x86_64 .note.gnu.property or 3125aaeed6ecSNathan Chancellor # compressed debug sections to x86_x32 properly: 3126aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/514 3127aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/1141 3128aaeed6ecSNathan Chancellor depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) 3129a7f7f624SMasahiro Yamada help 31305fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 31315fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 31325fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 31335fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 31345fd92e65SH. J. Lu 3135953fee1dSIngo Molnarconfig COMPAT_32 3136953fee1dSIngo Molnar def_bool y 3137953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 3138953fee1dSIngo Molnar select HAVE_UID16 3139953fee1dSIngo Molnar select OLD_SIGSUSPEND3 3140953fee1dSIngo Molnar 3141e279b6c1SSam Ravnborgconfig COMPAT 31423c2362e6SHarvey Harrison def_bool y 314383a44a4fSMasahiro Yamada depends on IA32_EMULATION || X86_X32_ABI 3144e279b6c1SSam Ravnborg 3145e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 31463120e25eSJan Beulich def_bool y 3147a9251280SLinus Torvalds depends on COMPAT 3148ee009e4aSDavid Howells 3149e279b6c1SSam Ravnborgendmenu 3150e279b6c1SSam Ravnborg 3151e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 3152e5beae16SKeith Packard def_bool y 3153e5beae16SKeith Packard depends on X86_32 3154e5beae16SKeith Packard 3155edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 31565e8ebd84SJason A. Donenfeld 31575e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 3158