1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0 2daa93fabSSam Ravnborg# Select 32 or 64 bit 3daa93fabSSam Ravnborgconfig 64BIT 4104daea1SMasahiro Yamada bool "64-bit kernel" if "$(ARCH)" = "x86" 5104daea1SMasahiro Yamada default "$(ARCH)" != "i386" 6a7f7f624SMasahiro Yamada help 7daa93fabSSam Ravnborg Say yes to build a 64-bit kernel - formerly known as x86_64 8daa93fabSSam Ravnborg Say no to build a 32-bit kernel - formerly known as i386 9daa93fabSSam Ravnborg 10daa93fabSSam Ravnborgconfig X86_32 113120e25eSJan Beulich def_bool y 123120e25eSJan Beulich depends on !64BIT 13341c787eSIngo Molnar # Options that are inherently 32-bit kernel only: 14341c787eSIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION 15341c787eSIngo Molnar select CLKSRC_I8253 16341c787eSIngo Molnar select CLONE_BACKWARDS 17157e118bSThomas Gleixner select GENERIC_VDSO_32 18117ed454SThomas Gleixner select HAVE_DEBUG_STACKOVERFLOW 19157e118bSThomas Gleixner select KMAP_LOCAL 20341c787eSIngo Molnar select MODULES_USE_ELF_REL 21341c787eSIngo Molnar select OLD_SIGACTION 222ca408d9SBrian Gerst select ARCH_SPLIT_ARG64 23daa93fabSSam Ravnborg 24daa93fabSSam Ravnborgconfig X86_64 253120e25eSJan Beulich def_bool y 263120e25eSJan Beulich depends on 64BIT 27d94e0685SIngo Molnar # Options that are inherently 64-bit kernel only: 284eb0716eSAlexandre Ghiti select ARCH_HAS_GIGANTIC_PAGE 29c12d3362SArd Biesheuvel select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 300bff0aaeSSuren Baghdasaryan select ARCH_SUPPORTS_PER_VMA_LOCK 31d94e0685SIngo Molnar select ARCH_USE_CMPXCHG_LOCKREF 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 381032c0baSSam Ravnborg 39518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE 40518049d9SSteven Rostedt (VMware) def_bool y 41518049d9SSteven Rostedt (VMware) depends on X86_32 42518049d9SSteven Rostedt (VMware) depends on FUNCTION_TRACER 43518049d9SSteven Rostedt (VMware) select DYNAMIC_FTRACE 44518049d9SSteven Rostedt (VMware) help 45518049d9SSteven Rostedt (VMware) We keep the static function tracing (!DYNAMIC_FTRACE) around 46518049d9SSteven Rostedt (VMware) in order to test the non static function tracing in the 47518049d9SSteven Rostedt (VMware) generic code, as other architectures still use it. But we 48518049d9SSteven Rostedt (VMware) only need to keep it around for x86_64. No need to keep it 49518049d9SSteven Rostedt (VMware) for x86_32. For x86_32, force DYNAMIC_FTRACE. 50d94e0685SIngo Molnar# 51d94e0685SIngo Molnar# Arch settings 52d94e0685SIngo Molnar# 53d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be 54d94e0685SIngo Molnar# ported to 32-bit as well. ) 55d94e0685SIngo Molnar# 568d5fffb9SSam Ravnborgconfig X86 573c2362e6SHarvey Harrison def_bool y 58c763ea26SIngo Molnar # 59c763ea26SIngo Molnar # Note: keep this list sorted alphabetically 60c763ea26SIngo Molnar # 616471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 626e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 63942fa985SYury Norov select ARCH_32BIT_OFF_T if X86_32 642a21ad57SThomas Gleixner select ARCH_CLOCKSOURCE_INIT 651f6d3a8fSMasami Hiramatsu select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 661e866974SAnshuman Khandual select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION 675c11f00bSDavid Hildenbrand select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 6891024b3cSAnshuman Khandual select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 69cebc774fSAnshuman Khandual select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) 701e866974SAnshuman Khandual select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE 7191dda51aSAleksey Makarov select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 72c2280be8SAnshuman Khandual select ARCH_HAS_CACHE_LINE_SIZE 731156b441SDavidlohr Bueso select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION 747c7077a7SThomas Gleixner select ARCH_HAS_CPU_FINALIZE_INIT 752792d84eSKees Cook select ARCH_HAS_CURRENT_STACK_POINTER 76fa5b6ec9SLaura Abbott select ARCH_HAS_DEBUG_VIRTUAL 77399145f9SAnshuman Khandual select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 7821266be9SDan Williams select ARCH_HAS_DEVMEM_IS_ALLOWED 79b1a57bbfSDouglas Anderson select ARCH_HAS_EARLY_DEBUG if KGDB 806471b825SIngo Molnar select ARCH_HAS_ELF_RANDOMIZE 8172d93104SLinus Torvalds select ARCH_HAS_FAST_MULTIPLIER 826974f0c4SDaniel Micay select ARCH_HAS_FORTIFY_SOURCE 83957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 84bece04b5SMarco Elver select ARCH_HAS_KCOV if X86_64 850c9c1d56SThiago Jung Bauermann select ARCH_HAS_MEM_ENCRYPT 8610bcc80eSMathieu Desnoyers select ARCH_HAS_MEMBARRIER_SYNC_CORE 8749f88c70SPaul E. McKenney select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 880ebeea8cSDaniel Borkmann select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 89c763ea26SIngo Molnar select ARCH_HAS_PMEM_API if X86_64 9017596731SRobin Murphy select ARCH_HAS_PTE_DEVMAP if X86_64 913010a5eaSLaurent Dufour select ARCH_HAS_PTE_SPECIAL 92eed9a328SYu Zhao select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2 930aed55afSDan Williams select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 94ec6347bbSDan Williams select ARCH_HAS_COPY_MC if X86_64 95d2852a22SDaniel Borkmann select ARCH_HAS_SET_MEMORY 96d253ca0cSRick Edgecombe select ARCH_HAS_SET_DIRECT_MAP 97ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_KERNEL_RWX 98ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_MODULE_RWX 99ac1ab12aSMathieu Desnoyers select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 10025c619e5SBrian Gerst select ARCH_HAS_SYSCALL_WRAPPER 101c6d30853SAndrey Ryabinin select ARCH_HAS_UBSAN_SANITIZE_ALL 1027e01ccb4SZong Li select ARCH_HAS_DEBUG_WX 10363703f37SKefeng Wang select ARCH_HAS_ZONE_DMA_SET if EXPERT 1046471b825SIngo Molnar select ARCH_HAVE_NMI_SAFE_CMPXCHG 1056471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 10677fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 1075e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 1083599fe12SThomas Gleixner select ARCH_STACKWALK 1092c870e61SArnd Bergmann select ARCH_SUPPORTS_ACPI 1106471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 1115d6ad668SMike Rapoport select ARCH_SUPPORTS_DEBUG_PAGEALLOC 112d283d422SPasha Tatashin select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 1136471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 11414df3267SThomas Gleixner select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 1153c516f89SSami Tolvanen select ARCH_SUPPORTS_CFI_CLANG if X86_64 1163c516f89SSami Tolvanen select ARCH_USES_CFI_TRAPS if X86_64 && CFI_CLANG 117583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG 118583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG_THIN 1196471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 120dce44566SAnshuman Khandual select ARCH_USE_MEMTEST 1216471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 1226471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 1232ce0d7f9SMark Brown select ARCH_USE_SYM_ANNOTATIONS 124ce4a4e56SAndy Lutomirski select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 12581c22041SDaniel Borkmann select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 126c763ea26SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 12751c2ee6dSNick Desaulniers select ARCH_WANTS_NO_INSTR 12807431506SAnshuman Khandual select ARCH_WANT_GENERAL_HUGETLB 1293876d4a3SAlexandre Ghiti select ARCH_WANT_HUGE_PMD_SHARE 13059612b24SNathan Chancellor select ARCH_WANT_LD_ORPHAN_WARN 1310b376f1eSAneesh Kumar K.V select ARCH_WANT_OPTIMIZE_VMEMMAP if X86_64 13238d8b4e6SHuang Ying select ARCH_WANTS_THP_SWAP if X86_64 133b5f06f64SBalbir Singh select ARCH_HAS_PARANOID_L1D_FLUSH 13410916706SShile Zhang select BUILDTIME_TABLE_SORT 1356471b825SIngo Molnar select CLKEVT_I8253 1366471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 1376471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 1387cf8f44aSAlexander Potapenko # Word-size accesses may read uninitialized data past the trailing \0 1397cf8f44aSAlexander Potapenko # in strings and cause false KMSAN reports. 1407cf8f44aSAlexander Potapenko select DCACHE_WORD_ACCESS if !KMSAN 1413aac3ebeSThomas Gleixner select DYNAMIC_SIGFRAME 14245471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 14345471cd9SLinus Torvalds select EDAC_SUPPORT 1446471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 1456471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 1466471b825SIngo Molnar select GENERIC_CMOS_UPDATE 1476471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 14861dc0f55SThomas Gleixner select GENERIC_CPU_VULNERABILITIES 1496471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 15027d6b4d1SThomas Gleixner select GENERIC_ENTRY 1516471b825SIngo Molnar select GENERIC_IOMAP 152c7d6c9ddSThomas Gleixner select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 1530fa115daSThomas Gleixner select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 154ad7a929fSThomas Gleixner select GENERIC_IRQ_MIGRATION if SMP 1556471b825SIngo Molnar select GENERIC_IRQ_PROBE 156c201c917SThomas Gleixner select GENERIC_IRQ_RESERVATION_MODE 1576471b825SIngo Molnar select GENERIC_IRQ_SHOW 1586471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 1592ae27137SSteven Price select GENERIC_PTDUMP 1606471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 1616471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 1627ac87074SVincenzo Frascino select GENERIC_GETTIMEOFDAY 163550a77a7SDmitry Safonov select GENERIC_VDSO_TIME_NS 1646ca297d4SPeter Zijlstra select GUP_GET_PXX_LOW_HIGH if X86_PAE 16517e5888eSHans de Goede select HARDIRQS_SW_RESEND 1667edaeb68SThomas Gleixner select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 167fcbfe812SNiklas Schnelle select HAS_IOPORT 1686471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 1696471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 1706471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 1716471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 1726471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 173eed1fceeSSong Liu select HAVE_ARCH_HUGE_VMALLOC if X86_64 1746471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 175b34006c4SArd Biesheuvel select HAVE_ARCH_JUMP_LABEL_RELATIVE 176d17a1d97SAndrey Ryabinin select HAVE_ARCH_KASAN if X86_64 1770609ae01SDaniel Axtens select HAVE_ARCH_KASAN_VMALLOC if X86_64 1781dc0da6eSAlexander Potapenko select HAVE_ARCH_KFENCE 1794ca8cc8dSAlexander Potapenko select HAVE_ARCH_KMSAN if X86_64 1806471b825SIngo Molnar select HAVE_ARCH_KGDB 1819e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 1829e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 1831b028f78SDmitry Safonov select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 184271ca788SArd Biesheuvel select HAVE_ARCH_PREL32_RELOCATIONS 1856471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 186f7d83c1cSKees Cook select HAVE_ARCH_THREAD_STRUCT_WHITELIST 187afaef01cSAlexander Popov select HAVE_ARCH_STACKLEAK 1886471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 1896471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 190a00cc7d9SMatthew Wilcox select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 191b64d8d1eSPeter Xu select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 1927677f7fdSAxel Rasmussen select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD 193e37e43a4SAndy Lutomirski select HAVE_ARCH_VMAP_STACK if X86_64 194fe950f60SKees Cook select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 195c763ea26SIngo Molnar select HAVE_ARCH_WITHIN_STACK_FRAMES 1962ff2b7ecSMasahiro Yamada select HAVE_ASM_MODVERSIONS 1976471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 1986471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 19924a9c541SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_USER if X86_64 20024a9c541SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER 2016471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 20203f16cd0SJosh Poimboeuf select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL 203280981d6SSathvika Vasireddy select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT 2044ed308c4SSteven Rostedt (Google) select HAVE_BUILDTIME_MCOUNT_SORT 2056471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 2069c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 207677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 20806aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 20902a474caSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 210562955feSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 211c316eb44SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 212503e4510SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 21303f5781bSWang YanQing select HAVE_EBPF_JIT 21458340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 2156630a8e5SChristoph Hellwig select HAVE_EISA 2165f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 21767a929e0SChristoph Hellwig select HAVE_FAST_GUP 218644e0e8dSSteven Rostedt (VMware) select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 2196471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 220d938ba17SDonglin Peng select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 2214a30e4c9SSteven Rostedt (VMware) select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) 2226471b825SIngo Molnar select HAVE_FUNCTION_TRACER 2236b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 2240067f129SK.Prasad select HAVE_HW_BREAKPOINT 2256471b825SIngo Molnar select HAVE_IOREMAP_PROT 226624db9eaSThomas Gleixner select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 2276471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 2284ab7674fSJosh Poimboeuf select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL 2296471b825SIngo Molnar select HAVE_KERNEL_BZIP2 2306471b825SIngo Molnar select HAVE_KERNEL_GZIP 2316471b825SIngo Molnar select HAVE_KERNEL_LZ4 2326471b825SIngo Molnar select HAVE_KERNEL_LZMA 2336471b825SIngo Molnar select HAVE_KERNEL_LZO 2346471b825SIngo Molnar select HAVE_KERNEL_XZ 235fb46d057SNick Terrell select HAVE_KERNEL_ZSTD 2366471b825SIngo Molnar select HAVE_KPROBES 2376471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 238540adea3SMasami Hiramatsu select HAVE_FUNCTION_ERROR_INJECTION 2396471b825SIngo Molnar select HAVE_KRETPROBES 240f3a112c0SMasami Hiramatsu select HAVE_RETHOOK 2416471b825SIngo Molnar select HAVE_KVM 2426471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 2430102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 244ee9f8fceSJosh Poimboeuf select HAVE_MOD_ARCH_SPECIFIC 2459f132f7eSJoel Fernandes (Google) select HAVE_MOVE_PMD 246be37c98dSKalesh Singh select HAVE_MOVE_PUD 24722102f45SJosh Poimboeuf select HAVE_NOINSTR_HACK if HAVE_OBJTOOL 24842a0bb3fSPetr Mladek select HAVE_NMI 249489e355bSJosh Poimboeuf select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL 25003f16cd0SJosh Poimboeuf select HAVE_OBJTOOL if X86_64 2516471b825SIngo Molnar select HAVE_OPTPROBES 2526471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 2536471b825SIngo Molnar select HAVE_PERF_EVENTS 254c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 25592e5aae4SNicholas Piggin select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 256eb01d42aSChristoph Hellwig select HAVE_PCI 257c5e63197SJiri Olsa select HAVE_PERF_REGS 258c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 259ff2e6d72SPeter Zijlstra select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 2601e9fdf21SPeter Zijlstra select MMU_GATHER_MERGE_VMAS 26100998085SThomas Gleixner select HAVE_POSIX_CPU_TIMERS_TASK_WORK 2626471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 26303f16cd0SJosh Poimboeuf select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION 2643c88ee19SMasami Hiramatsu select HAVE_FUNCTION_ARG_ACCESS_API 2657ecd19cfSKefeng Wang select HAVE_SETUP_PER_CPU_AREA 266cd1a41ceSThomas Gleixner select HAVE_SOFTIRQ_ON_OWN_STACK 267d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 26803f16cd0SJosh Poimboeuf select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 269e6d6c071SJosh Poimboeuf select HAVE_STATIC_CALL 27003f16cd0SJosh Poimboeuf select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL 27199cf983cSMark Rutland select HAVE_PREEMPT_DYNAMIC_CALL 272d6761b8fSMathieu Desnoyers select HAVE_RSEQ 27309498135SMiguel Ojeda select HAVE_RUST if X86_64 2746471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 2755f3da8c0SJosh Poimboeuf select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL 2766471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 2777c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 2787ac87074SVincenzo Frascino select HAVE_GENERIC_VDSO 2790c7ffa32SThomas Gleixner select HOTPLUG_PARALLEL if SMP && X86_64 28005736e4aSThomas Gleixner select HOTPLUG_SMT if SMP 2810c7ffa32SThomas Gleixner select HOTPLUG_SPLIT_STARTUP if SMP && X86_32 282c0185808SThomas Gleixner select IRQ_FORCED_THREADING 283c2508ec5SLinus Torvalds select LOCK_MM_AND_FIND_VMA 2847ecd19cfSKefeng Wang select NEED_PER_CPU_EMBED_FIRST_CHUNK 2857ecd19cfSKefeng Wang select NEED_PER_CPU_PAGE_FIRST_CHUNK 28686596f0aSChristoph Hellwig select NEED_SG_DMA_LENGTH 2872eac9c2dSChristoph Hellwig select PCI_DOMAINS if PCI 288625210cfSSinan Kaya select PCI_LOCKLESS_CONFIG if PCI 2896471b825SIngo Molnar select PERF_EVENTS 2903195ef59SPrarit Bhargava select RTC_LIB 291d6faca40SArnd Bergmann select RTC_MC146818_LIB 2926471b825SIngo Molnar select SPARSE_IRQ 2936471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 29415f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 2954aae683fSMasahiro Yamada select TRACE_IRQFLAGS_SUPPORT 2964510bffbSMark Rutland select TRACE_IRQFLAGS_NMI_SUPPORT 2976471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 2983b02a051SIngo Molnar select HAVE_ARCH_KCSAN if X86_64 2990c608dadSAubrey Li select PROC_PID_ARCH_STATUS if PROC_FS 30050468e43SJarkko Sakkinen select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX 301d49a0626SPeter Zijlstra select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16 302d49a0626SPeter Zijlstra select FUNCTION_ALIGNMENT_4B 3039e2b4be3SNayna Jain imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 304ceea991aSJiri Olsa select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 3057d8330a5SBalbir Singh 306ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 3073120e25eSJan Beulich def_bool y 3083120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 309ba7e4d13SIngo Molnar 31051b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 31151b26adaSLinus Torvalds string 31251b26adaSLinus Torvalds default "elf32-i386" if X86_32 31351b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 31451b26adaSLinus Torvalds 3158d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 3163c2362e6SHarvey Harrison def_bool y 3178d5fffb9SSam Ravnborg 3188d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 3193c2362e6SHarvey Harrison def_bool y 3208d5fffb9SSam Ravnborg 3218d5fffb9SSam Ravnborgconfig MMU 3223c2362e6SHarvey Harrison def_bool y 3238d5fffb9SSam Ravnborg 3249e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 3259e08f57dSDaniel Cashman default 28 if 64BIT 3269e08f57dSDaniel Cashman default 8 3279e08f57dSDaniel Cashman 3289e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 3299e08f57dSDaniel Cashman default 32 if 64BIT 3309e08f57dSDaniel Cashman default 16 3319e08f57dSDaniel Cashman 3329e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 3339e08f57dSDaniel Cashman default 8 3349e08f57dSDaniel Cashman 3359e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 3369e08f57dSDaniel Cashman default 16 3379e08f57dSDaniel Cashman 3388d5fffb9SSam Ravnborgconfig SBUS 3398d5fffb9SSam Ravnborg bool 3408d5fffb9SSam Ravnborg 3418d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 3423120e25eSJan Beulich def_bool y 3433120e25eSJan Beulich depends on ISA_DMA_API 3448d5fffb9SSam Ravnborg 345d911c67eSAlexander Potapenkoconfig GENERIC_CSUM 346d911c67eSAlexander Potapenko bool 347d911c67eSAlexander Potapenko default y if KMSAN || KASAN 348d911c67eSAlexander Potapenko 3498d5fffb9SSam Ravnborgconfig GENERIC_BUG 3503c2362e6SHarvey Harrison def_bool y 3518d5fffb9SSam Ravnborg depends on BUG 352b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 353b93a531eSJan Beulich 354b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 355b93a531eSJan Beulich bool 3568d5fffb9SSam Ravnborg 3578d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 3583120e25eSJan Beulich def_bool y 3593120e25eSJan Beulich depends on ISA_DMA_API 3608d5fffb9SSam Ravnborg 3611032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 3621032c0baSSam Ravnborg def_bool y 3631032c0baSSam Ravnborg 3649a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 3659a0b8415Svenkatesh.pallipadi@intel.com def_bool y 3668d5fffb9SSam Ravnborg 367801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 368801e4062SJohannes Berg def_bool y 369801e4062SJohannes Berg 370f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 371f4cb5700SJohannes Berg def_bool y 372f4cb5700SJohannes Berg 3738d5fffb9SSam Ravnborgconfig AUDIT_ARCH 374e0fd24a3SJan Beulich def_bool y if X86_64 3758d5fffb9SSam Ravnborg 376d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 377d6f2d75aSAndrey Ryabinin hex 378d6f2d75aSAndrey Ryabinin depends on KASAN 379d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 380d6f2d75aSAndrey Ryabinin 38169575d38SShane Wangconfig HAVE_INTEL_TXT 38269575d38SShane Wang def_bool y 3836ea30386SKees Cook depends on INTEL_IOMMU && ACPI 38469575d38SShane Wang 3856b0c3d44SSam Ravnborgconfig X86_32_SMP 3866b0c3d44SSam Ravnborg def_bool y 3876b0c3d44SSam Ravnborg depends on X86_32 && SMP 3886b0c3d44SSam Ravnborg 3896b0c3d44SSam Ravnborgconfig X86_64_SMP 3906b0c3d44SSam Ravnborg def_bool y 3916b0c3d44SSam Ravnborg depends on X86_64 && SMP 3926b0c3d44SSam Ravnborg 3932b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3942b144498SSrikar Dronamraju def_bool y 3952b144498SSrikar Dronamraju 396d20642f0SRob Herringconfig FIX_EARLYCON_MEM 397d20642f0SRob Herring def_bool y 398d20642f0SRob Herring 39994d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK 40094d49eb3SKirill A. Shutemov bool 40194d49eb3SKirill A. Shutemov 40298233368SKirill A. Shutemovconfig PGTABLE_LEVELS 40398233368SKirill A. Shutemov int 40477ef56e4SKirill A. Shutemov default 5 if X86_5LEVEL 40598233368SKirill A. Shutemov default 4 if X86_64 40698233368SKirill A. Shutemov default 3 if X86_PAE 40798233368SKirill A. Shutemov default 2 40898233368SKirill A. Shutemov 4092a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR 4102a61f474SMasahiro Yamada bool 4111b866781SNathan Chancellor default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT 4121b866781SNathan Chancellor default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) 4132a61f474SMasahiro Yamada help 4142a61f474SMasahiro Yamada We have to make sure stack protector is unconditionally disabled if 4153fb0fdb3SAndy Lutomirski the compiler produces broken code or if it does not let us control 4163fb0fdb3SAndy Lutomirski the segment on 32-bit kernels. 4172a61f474SMasahiro Yamada 418506f1d07SSam Ravnborgmenu "Processor type and features" 419506f1d07SSam Ravnborg 420506f1d07SSam Ravnborgconfig SMP 421506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 422a7f7f624SMasahiro Yamada help 423506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 4244a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 4254a474157SRobert Graffham than one CPU, say Y. 426506f1d07SSam Ravnborg 4274a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 428506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 429506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 4304a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 431506f1d07SSam Ravnborg will run faster if you say N here. 432506f1d07SSam Ravnborg 433506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 434506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 435506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 436506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 437506f1d07SSam Ravnborg 438506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 439506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 440506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 441506f1d07SSam Ravnborg 442ff61f079SJonathan Corbet See also <file:Documentation/arch/x86/i386/IO-APIC.rst>, 4434f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 444506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 445506f1d07SSam Ravnborg 446506f1d07SSam Ravnborg If you don't know what to do here, say N. 447506f1d07SSam Ravnborg 44806cd9a7dSYinghai Luconfig X86_X2APIC 44906cd9a7dSYinghai Lu bool "Support x2apic" 45019e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 451a7f7f624SMasahiro Yamada help 45206cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 45306cd9a7dSYinghai Lu 45406cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 45506cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 45606cd9a7dSYinghai Lu 457b8d1d163SDaniel Sneddon Some Intel systems circa 2022 and later are locked into x2APIC mode 458b8d1d163SDaniel Sneddon and can not fall back to the legacy APIC modes if SGX or TDX are 459e3998434SMateusz Jończyk enabled in the BIOS. They will boot with very reduced functionality 460e3998434SMateusz Jończyk without enabling this option. 461b8d1d163SDaniel Sneddon 46206cd9a7dSYinghai Lu If you don't know what to do here, say N. 46306cd9a7dSYinghai Lu 4646695c85bSYinghai Luconfig X86_MPPARSE 4654590d98fSAndy Shevchenko bool "Enable MPS table" if ACPI 4667a527688SJan Beulich default y 4675ab74722SIngo Molnar depends on X86_LOCAL_APIC 468a7f7f624SMasahiro Yamada help 4696695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4706695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4716695c85bSYinghai Lu 472ddd70cf9SJun Nakajimaconfig GOLDFISH 473ddd70cf9SJun Nakajima def_bool y 474ddd70cf9SJun Nakajima depends on X86_GOLDFISH 475ddd70cf9SJun Nakajima 476e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 477e6d42931SJohannes Weiner bool "x86 CPU resource control support" 4786fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 47959fe5a77SThomas Gleixner select KERNFS 480e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 48178e99b4aSFenghua Yu help 482e6d42931SJohannes Weiner Enable x86 CPU resource control support. 4836fe07ce3SBabu Moger 4846fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 4856fe07ce3SBabu Moger usage by the CPU. 4866fe07ce3SBabu Moger 4876fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 4886fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 4896fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 4906fe07ce3SBabu Moger 4916fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 4926fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 4936fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 49478e99b4aSFenghua Yu 49578e99b4aSFenghua Yu Say N if unsure. 49678e99b4aSFenghua Yu 4978425091fSRavikiran G Thirumalaiif X86_32 498a0d0bb4dSRandy Dunlapconfig X86_BIGSMP 499a0d0bb4dSRandy Dunlap bool "Support for big SMP systems with more than 8 CPUs" 500a0d0bb4dSRandy Dunlap depends on SMP 501a7f7f624SMasahiro Yamada help 502e133f6eaSRandy Dunlap This option is needed for the systems that have more than 8 CPUs. 503a0d0bb4dSRandy Dunlap 504c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 505c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 506c5c606d9SRavikiran G Thirumalai default y 507a7f7f624SMasahiro Yamada help 50806ac8346SIngo Molnar If you disable this option then the kernel will only support 50906ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 51006ac8346SIngo Molnar systems out there.) 51106ac8346SIngo Molnar 5128425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5138425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 514cb7b8023SBen Hutchings Goldfish (Android emulator) 5158425091fSRavikiran G Thirumalai AMD Elan 5168425091fSRavikiran G Thirumalai RDC R-321x SoC 5178425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 51883125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 5193f4110a4SThomas Gleixner Moorestown MID devices 52006ac8346SIngo Molnar 52106ac8346SIngo Molnar If you have one of these systems, or if you want to build a 52206ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 523758cd94aSJuerg Haefligerendif # X86_32 52406ac8346SIngo Molnar 5258425091fSRavikiran G Thirumalaiif X86_64 5268425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 5278425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 5288425091fSRavikiran G Thirumalai default y 529a7f7f624SMasahiro Yamada help 5308425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 5318425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 5328425091fSRavikiran G Thirumalai systems out there.) 5338425091fSRavikiran G Thirumalai 5348425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5358425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 53644b111b5SSteffen Persvold Numascale NumaChip 5378425091fSRavikiran G Thirumalai ScaleMP vSMP 5388425091fSRavikiran G Thirumalai SGI Ultraviolet 5398425091fSRavikiran G Thirumalai 5408425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5418425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 542758cd94aSJuerg Haefligerendif # X86_64 543c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 544c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 54544b111b5SSteffen Persvoldconfig X86_NUMACHIP 54644b111b5SSteffen Persvold bool "Numascale NumaChip" 54744b111b5SSteffen Persvold depends on X86_64 54844b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 54944b111b5SSteffen Persvold depends on NUMA 55044b111b5SSteffen Persvold depends on SMP 55144b111b5SSteffen Persvold depends on X86_X2APIC 552f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 553a7f7f624SMasahiro Yamada help 55444b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 55544b111b5SSteffen Persvold enable more than ~168 cores. 55644b111b5SSteffen Persvold If you don't have one of these, you should say N here. 55703b48632SNick Piggin 5586a48565eSIngo Molnarconfig X86_VSMP 559c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5606276a074SBorislav Petkov select HYPERVISOR_GUEST 5616a48565eSIngo Molnar select PARAVIRT 5626a48565eSIngo Molnar depends on X86_64 && PCI 563c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 564ead91d4bSShai Fultheim depends on SMP 565a7f7f624SMasahiro Yamada help 5666a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5676a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5686a48565eSIngo Molnar if you have one of these machines. 5696a48565eSIngo Molnar 570c5c606d9SRavikiran G Thirumalaiconfig X86_UV 571c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 572c5c606d9SRavikiran G Thirumalai depends on X86_64 573c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 57454c28d29SJack Steiner depends on NUMA 5751ecb4ae5SAndrew Morton depends on EFI 576c2209ea5SIngo Molnar depends on KEXEC_CORE 5779d6c26e7SSuresh Siddha depends on X86_X2APIC 5781222e564SIngo Molnar depends on PCI 579a7f7f624SMasahiro Yamada help 580c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 581c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 582c5c606d9SRavikiran G Thirumalai 583c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 584c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 585506f1d07SSam Ravnborg 586ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 587ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 588cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 589a7f7f624SMasahiro Yamada help 590ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 591ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 592ddd70cf9SJun Nakajima Goldfish emulator say N here. 593ddd70cf9SJun Nakajima 594c751e17bSThomas Gleixnerconfig X86_INTEL_CE 595c751e17bSThomas Gleixner bool "CE4100 TV platform" 596c751e17bSThomas Gleixner depends on PCI 597c751e17bSThomas Gleixner depends on PCI_GODIRECT 5986084a6e2SJiang Liu depends on X86_IO_APIC 599c751e17bSThomas Gleixner depends on X86_32 600c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 60137bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 602da6b737bSSebastian Andrzej Siewior select OF 603da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 604a7f7f624SMasahiro Yamada help 605c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 606c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 607c751e17bSThomas Gleixner boxes and media devices. 608c751e17bSThomas Gleixner 6094cb9b00fSDavid Cohenconfig X86_INTEL_MID 61043605ef1SAlan Cox bool "Intel MID platform support" 61143605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 612edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 6131ea7c673SAlan Cox depends on PCI 6143fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 6151ea7c673SAlan Cox depends on X86_IO_APIC 6164cb9b00fSDavid Cohen select I2C 6177c9c3a1eSAlan Cox select DW_APB_TIMER 61854b34aa0SMika Westerberg select INTEL_SCU_PCI 619a7f7f624SMasahiro Yamada help 6204cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 6214cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 6224cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 6231ea7c673SAlan Cox 6244cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 6254cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 62643605ef1SAlan Cox 6278bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6288bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6298bbc2a13SBryan O'Donoghue depends on X86_32 6308bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6318bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6328bbc2a13SBryan O'Donoghue depends on X86_TSC 6338bbc2a13SBryan O'Donoghue depends on PCI 6348bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6358bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6368bbc2a13SBryan O'Donoghue select IOSF_MBI 6378bbc2a13SBryan O'Donoghue select INTEL_IMR 6389ab6eb51SAndy Shevchenko select COMMON_CLK 639a7f7f624SMasahiro Yamada help 6408bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6418bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6428bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6438bbc2a13SBryan O'Donoghue 6443d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6453d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6465962dd22SSinan Kaya depends on X86 && ACPI && PCI 6473d48aab1SMika Westerberg select COMMON_CLK 6480f531431SMathias Nyman select PINCTRL 649eebb3e8dSAndy Shevchenko select IOSF_MBI 650a7f7f624SMasahiro Yamada help 6513d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6523d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6530f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6540f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6553d48aab1SMika Westerberg 65692082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 65792082a88SKen Xue bool "AMD ACPI2Platform devices support" 65892082a88SKen Xue depends on ACPI 65992082a88SKen Xue select COMMON_CLK 66092082a88SKen Xue select PINCTRL 661a7f7f624SMasahiro Yamada help 66292082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 66392082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 66492082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 66592082a88SKen Xue implemented under PINCTRL subsystem. 66692082a88SKen Xue 667ced3ce76SDavid E. Boxconfig IOSF_MBI 668ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 669ced3ce76SDavid E. Box depends on PCI 670a7f7f624SMasahiro Yamada help 671ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 672ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 673ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 674ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 675ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 676ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 677ced3ce76SDavid E. Box This list is not meant to be exclusive. 678ced3ce76SDavid E. Box - BayTrail 679ced3ce76SDavid E. Box - Braswell 680ced3ce76SDavid E. Box - Quark 681ced3ce76SDavid E. Box 682ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 683ced3ce76SDavid E. Box 684ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 685ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 686ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 687a7f7f624SMasahiro Yamada help 688ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 689ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 690ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 691ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 692ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 693ed2226bdSDavid E. Box device they want to access. 694ed2226bdSDavid E. Box 695ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 696ed2226bdSDavid E. Box 697c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 698c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 699506f1d07SSam Ravnborg depends on X86_32 700c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 701c5c606d9SRavikiran G Thirumalai select M486 702c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 703a7f7f624SMasahiro Yamada help 704c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 705c5c606d9SRavikiran G Thirumalai as R-8610-(G). 706c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 707c5c606d9SRavikiran G Thirumalai 708e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7099c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7109c398017SIngo Molnar depends on X86_32 && SMP 711c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 712a7f7f624SMasahiro Yamada help 713b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 714b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 715b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 716b5660ba7SH. Peter Anvin one and will fallback to default. 717d49c4288SYinghai Lu 718c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 719d49c4288SYinghai Lu 720d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7216fc108a0SJan Beulich def_bool y 722d949f36fSLinus Torvalds # MCE code calls memory_failure(): 723d949f36fSLinus Torvalds depends on X86_MCE 724d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 725d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 726d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 727d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 728d949f36fSLinus Torvalds 72983125a3aSAlessandro Rubiniconfig STA2X11 73083125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 73183125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 73283125a3aSAlessandro Rubini select SWIOTLB 73383125a3aSAlessandro Rubini select MFD_STA2X11 7340145071bSLinus Walleij select GPIOLIB 735a7f7f624SMasahiro Yamada help 73683125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 73783125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 73883125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 73983125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 74083125a3aSAlessandro Rubini standard PC machines. 74183125a3aSAlessandro Rubini 74282148d1dSShérabconfig X86_32_IRIS 74382148d1dSShérab tristate "Eurobraille/Iris poweroff module" 74482148d1dSShérab depends on X86_32 745a7f7f624SMasahiro Yamada help 74682148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 74782148d1dSShérab to shut themselves down properly. A special I/O sequence is 74882148d1dSShérab needed to do so, which is what this module does at 74982148d1dSShérab kernel shutdown. 75082148d1dSShérab 75182148d1dSShérab This is only for Iris machines from EuroBraille. 75282148d1dSShérab 75382148d1dSShérab If unused, say N. 75482148d1dSShérab 755ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7563c2362e6SHarvey Harrison def_bool y 7573c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 758a87d0914SKen Chen depends on X86 759a7f7f624SMasahiro Yamada help 760506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 761506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 762506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 763506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 764506f1d07SSam Ravnborg 765506f1d07SSam Ravnborg If in doubt, say "Y". 766506f1d07SSam Ravnborg 7676276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7686276a074SBorislav Petkov bool "Linux guest support" 769a7f7f624SMasahiro Yamada help 7706276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7716276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7726276a074SBorislav Petkov setup. 773506f1d07SSam Ravnborg 7746276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7756276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 776506f1d07SSam Ravnborg 7776276a074SBorislav Petkovif HYPERVISOR_GUEST 778506f1d07SSam Ravnborg 779e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 780e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 781a0e2bf7cSJuergen Gross depends on HAVE_STATIC_CALL 782a7f7f624SMasahiro Yamada help 783e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 784e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 785e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 786e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 787e61bd94aSEduardo Pereira Habkost 788c00a280aSJuergen Grossconfig PARAVIRT_XXL 789c00a280aSJuergen Gross bool 790c00a280aSJuergen Gross 7916276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7926276a074SBorislav Petkov bool "paravirt-ops debugging" 7936276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 794a7f7f624SMasahiro Yamada help 7956276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 7966276a074SBorislav Petkov a paravirt_op is missing when it is called. 7976276a074SBorislav Petkov 798b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 799b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 8006ea30386SKees Cook depends on PARAVIRT && SMP 801a7f7f624SMasahiro Yamada help 802b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 803b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 804b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 805b4ecc126SJeremy Fitzhardinge 8064c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 8074c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 808b4ecc126SJeremy Fitzhardinge 8094c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 810b4ecc126SJeremy Fitzhardinge 811ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 812ecca2502SZhao Yakui def_bool n 813ecca2502SZhao Yakui 8146276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8156276a074SBorislav Petkov 8166276a074SBorislav Petkovconfig KVM_GUEST 8176276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8186276a074SBorislav Petkov depends on PARAVIRT 8196276a074SBorislav Petkov select PARAVIRT_CLOCK 820a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 821b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8226276a074SBorislav Petkov default y 823a7f7f624SMasahiro Yamada help 8246276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8256276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8266276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8276276a074SBorislav Petkov underlying device model, the host provides the guest with 8286276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8296276a074SBorislav Petkov 830a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 831a1c4423bSMarcelo Tosatti def_bool n 832a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 833a1c4423bSMarcelo Tosatti help 834a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 835a1c4423bSMarcelo Tosatti 8367733607fSMaran Wilsonconfig PVH 8377733607fSMaran Wilson bool "Support for running PVH guests" 838a7f7f624SMasahiro Yamada help 8397733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8407733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8417733607fSMaran Wilson 8426276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8436276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8446276a074SBorislav Petkov depends on PARAVIRT 845a7f7f624SMasahiro Yamada help 8466276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8476276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8486276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8496276a074SBorislav Petkov that, there can be a small performance impact. 8506276a074SBorislav Petkov 8516276a074SBorislav Petkov If in doubt, say N here. 8526276a074SBorislav Petkov 8537af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8547af192c9SGerd Hoffmann bool 8557af192c9SGerd Hoffmann 8564a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8574a362601SJan Kiszka bool "Jailhouse non-root cell support" 858abde587bSArnd Bergmann depends on X86_64 && PCI 85987e65d05SJan Kiszka select X86_PM_TIMER 860a7f7f624SMasahiro Yamada help 8614a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8624a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8634a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8644a362601SJan Kiszka 865ec7972c9SZhao Yakuiconfig ACRN_GUEST 866ec7972c9SZhao Yakui bool "ACRN Guest support" 867ec7972c9SZhao Yakui depends on X86_64 868498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 869ec7972c9SZhao Yakui help 870ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 871ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 872ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 873ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 874ec7972c9SZhao Yakui found in https://projectacrn.org/. 875ec7972c9SZhao Yakui 87659bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST 87759bd54a8SKuppuswamy Sathyanarayanan bool "Intel TDX (Trust Domain Extensions) - Guest Support" 87859bd54a8SKuppuswamy Sathyanarayanan depends on X86_64 && CPU_SUP_INTEL 87959bd54a8SKuppuswamy Sathyanarayanan depends on X86_X2APIC 88075d090fdSKirill A. Shutemov depends on EFI_STUB 88141394e33SKirill A. Shutemov select ARCH_HAS_CC_PLATFORM 882968b4931SKirill A. Shutemov select X86_MEM_ENCRYPT 88377a512e3SSean Christopherson select X86_MCE 88475d090fdSKirill A. Shutemov select UNACCEPTED_MEMORY 88559bd54a8SKuppuswamy Sathyanarayanan help 88659bd54a8SKuppuswamy Sathyanarayanan Support running as a guest under Intel TDX. Without this support, 88759bd54a8SKuppuswamy Sathyanarayanan the guest kernel can not boot or run under TDX. 88859bd54a8SKuppuswamy Sathyanarayanan TDX includes memory encryption and integrity capabilities 88959bd54a8SKuppuswamy Sathyanarayanan which protect the confidentiality and integrity of guest 89059bd54a8SKuppuswamy Sathyanarayanan memory contents and CPU state. TDX guests are protected from 89159bd54a8SKuppuswamy Sathyanarayanan some attacks from the VMM. 89259bd54a8SKuppuswamy Sathyanarayanan 8936276a074SBorislav Petkovendif # HYPERVISOR_GUEST 89497349135SJeremy Fitzhardinge 895506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 896506f1d07SSam Ravnborg 897506f1d07SSam Ravnborgconfig HPET_TIMER 8983c2362e6SHarvey Harrison def_bool X86_64 899506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 900a7f7f624SMasahiro Yamada help 901506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 902506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 903506f1d07SSam Ravnborg present. 904506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 905506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 906506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 9074e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 9084e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 909506f1d07SSam Ravnborg 910506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 911506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 912506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 913506f1d07SSam Ravnborg 914506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 915506f1d07SSam Ravnborg 916506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 9173c2362e6SHarvey Harrison def_bool y 9183228e1dcSAnand K Mistry depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 919506f1d07SSam Ravnborg 9206a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 921506f1d07SSam Ravnborg# The code disables itself when not needed. 9227ae9392cSThomas Petazzoniconfig DMI 9237ae9392cSThomas Petazzoni default y 924cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9256a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 926a7f7f624SMasahiro Yamada help 9277ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9287ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9297ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9307ae9392cSThomas Petazzoni BIOS code. 9317ae9392cSThomas Petazzoni 932506f1d07SSam Ravnborgconfig GART_IOMMU 93338901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 9342f9237d4SChristoph Hellwig select DMA_OPS 935a4ce5a48SChristoph Hellwig select IOMMU_HELPER 936506f1d07SSam Ravnborg select SWIOTLB 93723ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 938a7f7f624SMasahiro Yamada help 939ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 940ced3c42cSIngo Molnar GART based hardware IOMMUs. 941ced3c42cSIngo Molnar 942ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 943ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 944ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 945ced3c42cSIngo Molnar 946ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 947ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 948ced3c42cSIngo Molnar 949ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 950ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 951ced3c42cSIngo Molnar 32-bit limited device. 952ced3c42cSIngo Molnar 953ced3c42cSIngo Molnar If unsure, say Y. 954506f1d07SSam Ravnborg 9558b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT 9568b766b0fSMichal Suchanek bool 9578b766b0fSMichal Suchanek help 9588b766b0fSMichal Suchanek If true, at least one selected framebuffer driver can take advantage 9598b766b0fSMichal Suchanek of VESA video modes set at an early boot stage via the vga= parameter. 9608b766b0fSMichal Suchanek 9611184dc2fSMike Travisconfig MAXSMP 962ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9636ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 96436f5101aSMike Travis select CPUMASK_OFFSTACK 965a7f7f624SMasahiro Yamada help 966ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9671184dc2fSMike Travis If unsure, say N. 968506f1d07SSam Ravnborg 969aec6487eSIngo Molnar# 970aec6487eSIngo Molnar# The maximum number of CPUs supported: 971aec6487eSIngo Molnar# 972aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 973aec6487eSIngo Molnar# and which can be configured interactively in the 974aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 975aec6487eSIngo Molnar# 976aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 977aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 978aec6487eSIngo Molnar# 979aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 980aec6487eSIngo Molnar# interactive configuration. ) 981aec6487eSIngo Molnar# 982a0d0bb4dSRandy Dunlap 983aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 984a0d0bb4dSRandy Dunlap int 985aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 986a0d0bb4dSRandy Dunlap default 1 if !SMP 987a0d0bb4dSRandy Dunlap default 2 988a0d0bb4dSRandy Dunlap 989aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 990a0d0bb4dSRandy Dunlap int 991a0d0bb4dSRandy Dunlap depends on X86_32 992aec6487eSIngo Molnar default 64 if SMP && X86_BIGSMP 993aec6487eSIngo Molnar default 8 if SMP && !X86_BIGSMP 994a0d0bb4dSRandy Dunlap default 1 if !SMP 995a0d0bb4dSRandy Dunlap 996aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 997a0d0bb4dSRandy Dunlap int 998a0d0bb4dSRandy Dunlap depends on X86_64 9991edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 10001edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 1001a0d0bb4dSRandy Dunlap default 1 if !SMP 1002aec6487eSIngo Molnar 1003aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 1004aec6487eSIngo Molnar int 1005aec6487eSIngo Molnar depends on X86_32 1006aec6487eSIngo Molnar default 32 if X86_BIGSMP 1007aec6487eSIngo Molnar default 8 if SMP 1008aec6487eSIngo Molnar default 1 if !SMP 1009aec6487eSIngo Molnar 1010aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 1011aec6487eSIngo Molnar int 1012aec6487eSIngo Molnar depends on X86_64 1013a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 1014a0d0bb4dSRandy Dunlap default 64 if SMP 1015aec6487eSIngo Molnar default 1 if !SMP 1016a0d0bb4dSRandy Dunlap 1017506f1d07SSam Ravnborgconfig NR_CPUS 101836f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 1019aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1020aec6487eSIngo Molnar default NR_CPUS_DEFAULT 1021a7f7f624SMasahiro Yamada help 1022506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 1023bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1024cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 1025506f1d07SSam Ravnborg minimum value which makes sense is 2. 1026506f1d07SSam Ravnborg 1027aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 1028aec6487eSIngo Molnar to the kernel image. 1029506f1d07SSam Ravnborg 103066558b73STim Chenconfig SCHED_CLUSTER 103166558b73STim Chen bool "Cluster scheduler support" 103266558b73STim Chen depends on SMP 103366558b73STim Chen default y 103466558b73STim Chen help 103566558b73STim Chen Cluster scheduler support improves the CPU scheduler's decision 103666558b73STim Chen making when dealing with machines that have clusters of CPUs. 103766558b73STim Chen Cluster usually means a couple of CPUs which are placed closely 103866558b73STim Chen by sharing mid-level caches, last-level cache tags or internal 103966558b73STim Chen busses. 104066558b73STim Chen 1041506f1d07SSam Ravnborgconfig SCHED_SMT 1042dbe73364SThomas Gleixner def_bool y if SMP 1043506f1d07SSam Ravnborg 1044506f1d07SSam Ravnborgconfig SCHED_MC 10453c2362e6SHarvey Harrison def_bool y 10463c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1047c8e56d20SBorislav Petkov depends on SMP 1048a7f7f624SMasahiro Yamada help 1049506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1050506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1051506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1052506f1d07SSam Ravnborg 1053de966cf4STim Chenconfig SCHED_MC_PRIO 1054de966cf4STim Chen bool "CPU core priorities scheduler support" 10550a21fc12SIngo Molnar depends on SCHED_MC && CPU_SUP_INTEL 10560a21fc12SIngo Molnar select X86_INTEL_PSTATE 10570a21fc12SIngo Molnar select CPU_FREQ 1058de966cf4STim Chen default y 1059a7f7f624SMasahiro Yamada help 1060de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1061de966cf4STim Chen core ordering determined at manufacturing time, which allows 1062de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1063de966cf4STim Chen single threaded workloads) than others. 1064de966cf4STim Chen 1065de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1066de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1067de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1068de966cf4STim Chen overall system performance can be achieved. 1069de966cf4STim Chen 1070de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1071de966cf4STim Chen 1072de966cf4STim Chen If unsure say Y here. 10735e76b2abSTim Chen 107430b8b006SThomas Gleixnerconfig UP_LATE_INIT 107530b8b006SThomas Gleixner def_bool y 1076ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 107730b8b006SThomas Gleixner 1078506f1d07SSam Ravnborgconfig X86_UP_APIC 107950849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 108050849eefSJan Beulich default PCI_MSI 108138a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1082a7f7f624SMasahiro Yamada help 1083506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1084506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1085506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1086506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1087506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1088506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1089506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1090506f1d07SSam Ravnborg lockups. 1091506f1d07SSam Ravnborg 1092506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1093506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1094506f1d07SSam Ravnborg depends on X86_UP_APIC 1095a7f7f624SMasahiro Yamada help 1096506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1097506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1098506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1099506f1d07SSam Ravnborg 1100506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1101506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1102506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1103506f1d07SSam Ravnborg 1104506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 11053c2362e6SHarvey Harrison def_bool y 11060dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1107b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 1108506f1d07SSam Ravnborg 1109506f1d07SSam Ravnborgconfig X86_IO_APIC 1110b1da1e71SJan Beulich def_bool y 1111b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1112506f1d07SSam Ravnborg 111341b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 111441b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 111541b9eb26SStefan Assmann depends on X86_IO_APIC 1116a7f7f624SMasahiro Yamada help 111741b9eb26SStefan Assmann This option enables a workaround that fixes a source of 111841b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 111941b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 112041b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 112141b9eb26SStefan Assmann 112241b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 112341b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 112441b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 112541b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 112641b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 112741b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 112841b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 112941b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 113041b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 113141b9eb26SStefan Assmann down (vital) interrupt lines. 113241b9eb26SStefan Assmann 113341b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 113441b9eb26SStefan Assmann increased on these systems. 113541b9eb26SStefan Assmann 1136506f1d07SSam Ravnborgconfig X86_MCE 1137bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1138648ed940SChen, Gong select GENERIC_ALLOCATOR 1139e57dbaf7SBorislav Petkov default y 1140a7f7f624SMasahiro Yamada help 1141bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1142bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1143506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1144bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11454efc0670SAndi Kleen 11465de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11475de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11485de97c9fSTony Luck depends on X86_MCE 1149a7f7f624SMasahiro Yamada help 11505de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11515de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11525de97c9fSTony Luck rasdaemon solution. 11535de97c9fSTony Luck 1154506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11553c2362e6SHarvey Harrison def_bool y 11563c2362e6SHarvey Harrison prompt "Intel MCE features" 1157c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1158a7f7f624SMasahiro Yamada help 1159506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1160506f1d07SSam Ravnborg the thermal monitor. 1161506f1d07SSam Ravnborg 1162506f1d07SSam Ravnborgconfig X86_MCE_AMD 11633c2362e6SHarvey Harrison def_bool y 11643c2362e6SHarvey Harrison prompt "AMD MCE features" 1165f5382de9SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1166a7f7f624SMasahiro Yamada help 1167506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1168506f1d07SSam Ravnborg the DRAM Error Threshold. 1169506f1d07SSam Ravnborg 11704efc0670SAndi Kleenconfig X86_ANCIENT_MCE 11716fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1172c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1173a7f7f624SMasahiro Yamada help 11744efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 11755065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 11764efc0670SAndi Kleen line. 11774efc0670SAndi Kleen 1178b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1179b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 11806fc108a0SJan Beulich def_bool y 1181b2762686SAndi Kleen 1182ea149b36SAndi Kleenconfig X86_MCE_INJECT 1183bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1184ea149b36SAndi Kleen tristate "Machine check injector support" 1185a7f7f624SMasahiro Yamada help 1186ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1187ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1188ea149b36SAndi Kleen QA it is safe to say n. 1189ea149b36SAndi Kleen 119007dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1191e633c65aSKan Liang 11925aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 11931e642812SIngo Molnar bool "Legacy VM86 support" 1194506f1d07SSam Ravnborg depends on X86_32 1195a7f7f624SMasahiro Yamada help 11965aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 11975aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 11985aef51c3SAndy Lutomirski 11995aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 12005aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 12015aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 12025aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 12035aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 12041e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 12051e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 12061e642812SIngo Molnar mode might be faster than emulation and you might want to 12071e642812SIngo Molnar enable this option. 12085aef51c3SAndy Lutomirski 12091e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 12101e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 12111e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 12121e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 12135aef51c3SAndy Lutomirski 12141e642812SIngo Molnar Enabling this option increases the complexity of the kernel 12151e642812SIngo Molnar and slows down exception handling a tiny bit. 12165aef51c3SAndy Lutomirski 12171e642812SIngo Molnar If unsure, say N here. 12185aef51c3SAndy Lutomirski 12195aef51c3SAndy Lutomirskiconfig VM86 12205aef51c3SAndy Lutomirski bool 12215aef51c3SAndy Lutomirski default X86_LEGACY_VM86 122234273f41SH. Peter Anvin 122334273f41SH. Peter Anvinconfig X86_16BIT 122434273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 122534273f41SH. Peter Anvin default y 1226a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1227a7f7f624SMasahiro Yamada help 122834273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 122934273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 123034273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 123134273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 123234273f41SH. Peter Anvin 123334273f41SH. Peter Anvinconfig X86_ESPFIX32 123434273f41SH. Peter Anvin def_bool y 123534273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1236506f1d07SSam Ravnborg 1237197725deSH. Peter Anvinconfig X86_ESPFIX64 1238197725deSH. Peter Anvin def_bool y 123934273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1240506f1d07SSam Ravnborg 12411ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12421ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12431ad83c85SAndy Lutomirski default y 12441ad83c85SAndy Lutomirski depends on X86_64 1245a7f7f624SMasahiro Yamada help 12461ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12471ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12481ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12491ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12501ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12511ad83c85SAndy Lutomirski 0xffffffffff600?00. 12521ad83c85SAndy Lutomirski 12531ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12541ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12551ad83c85SAndy Lutomirski 12561ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12571ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12581ad83c85SAndy Lutomirski 1259111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1260111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1261a24ca997SThomas Gleixner default y 1262a7f7f624SMasahiro Yamada help 1263111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1264111e7b15SThomas Gleixner for legacy applications. 1265111e7b15SThomas Gleixner 1266c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1267c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1268c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1269c8137aceSThomas Gleixner capabilities and permission from potentially active security 1270c8137aceSThomas Gleixner modules. 1271c8137aceSThomas Gleixner 1272c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1273c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1274a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1275a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1276c8137aceSThomas Gleixner 1277506f1d07SSam Ravnborgconfig TOSHIBA 1278506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1279506f1d07SSam Ravnborg depends on X86_32 1280a7f7f624SMasahiro Yamada help 1281506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1282506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1283506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1284506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1285506f1d07SSam Ravnborg 1286506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1287506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1288506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1289506f1d07SSam Ravnborg 1290506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1291506f1d07SSam Ravnborg Say N otherwise. 1292506f1d07SSam Ravnborg 1293506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 12949ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 12959ba16087SJan Beulich depends on X86_32 1296a7f7f624SMasahiro Yamada help 1297506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1298506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1299506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1300506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1301506f1d07SSam Ravnborg system. 1302506f1d07SSam Ravnborg 1303506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 13045e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1305506f1d07SSam Ravnborg 1306506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1307506f1d07SSam Ravnborg enable this option even if you don't need it. 1308506f1d07SSam Ravnborg Say N otherwise. 1309506f1d07SSam Ravnborg 1310506f1d07SSam Ravnborgconfig MICROCODE 13119a2bc335SBorislav Petkov bool "CPU microcode loading support" 13129a2bc335SBorislav Petkov default y 131380030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 1314a7f7f624SMasahiro Yamada help 1315506f1d07SSam Ravnborg If you say Y here, you will be able to update the microcode on 13165f9c01aaSBorislav Petkov Intel and AMD processors. The Intel support is for the IA32 family, 13175f9c01aaSBorislav Petkov e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 13185f9c01aaSBorislav Petkov AMD support is for families 0x10 and later. You will obviously need 13195f9c01aaSBorislav Petkov the actual microcode binary data itself which is not shipped with 13205f9c01aaSBorislav Petkov the Linux kernel. 1321506f1d07SSam Ravnborg 13225f9c01aaSBorislav Petkov The preferred method to load microcode from a detached initrd is described 1323ff61f079SJonathan Corbet in Documentation/arch/x86/microcode.rst. For that you need to enable 13245f9c01aaSBorislav Petkov CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 13255f9c01aaSBorislav Petkov initrd for microcode blobs. 1326506f1d07SSam Ravnborg 1327c508c46eSBenjamin Gilbert In addition, you can build the microcode into the kernel. For that you 1328c508c46eSBenjamin Gilbert need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1329c508c46eSBenjamin Gilbert config option. 1330506f1d07SSam Ravnborg 13318d86f390SPeter Orubaconfig MICROCODE_INTEL 1332e43f6e67SBorislav Petkov bool "Intel microcode loading support" 13339c55d99eSBorislav Petkov depends on CPU_SUP_INTEL && MICROCODE 13348d86f390SPeter Oruba default MICROCODE 1335a7f7f624SMasahiro Yamada help 13368d86f390SPeter Oruba This options enables microcode patch loading support for Intel 13378d86f390SPeter Oruba processors. 13388d86f390SPeter Oruba 1339b8989db9SAlan For the current Intel microcode data package go to 1340b8989db9SAlan <https://downloadcenter.intel.com> and search for 1341b8989db9SAlan 'Linux Processor Microcode Data File'. 13428d86f390SPeter Oruba 134380cc9f10SPeter Orubaconfig MICROCODE_AMD 1344e43f6e67SBorislav Petkov bool "AMD microcode loading support" 13459c55d99eSBorislav Petkov depends on CPU_SUP_AMD && MICROCODE 1346a7f7f624SMasahiro Yamada help 134780cc9f10SPeter Oruba If you select this option, microcode patch loading support for AMD 134880cc9f10SPeter Oruba processors will be enabled. 134980cc9f10SPeter Oruba 1350a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING 1351a77a94f8SBorislav Petkov bool "Late microcode loading (DANGEROUS)" 1352c02f48e0SBorislav Petkov default n 1353506f1d07SSam Ravnborg depends on MICROCODE 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, 1359a77a94f8SBorislav Petkov use this at your own risk. Late loading taints the kernel too. 1360506f1d07SSam Ravnborg 1361506f1d07SSam Ravnborgconfig X86_MSR 1362506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1363a7f7f624SMasahiro Yamada help 1364506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1365506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1366506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1367506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1368506f1d07SSam Ravnborg systems. 1369506f1d07SSam Ravnborg 1370506f1d07SSam Ravnborgconfig X86_CPUID 1371506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1372a7f7f624SMasahiro Yamada help 1373506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1374506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1375506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1376506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1377506f1d07SSam Ravnborg 1378506f1d07SSam Ravnborgchoice 1379506f1d07SSam Ravnborg prompt "High Memory Support" 13806fc108a0SJan Beulich default HIGHMEM4G 1381506f1d07SSam Ravnborg depends on X86_32 1382506f1d07SSam Ravnborg 1383506f1d07SSam Ravnborgconfig NOHIGHMEM 1384506f1d07SSam Ravnborg bool "off" 1385a7f7f624SMasahiro Yamada help 1386506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1387506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1388506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1389506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1390506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1391506f1d07SSam Ravnborg "high memory". 1392506f1d07SSam Ravnborg 1393506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1394506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1395506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1396506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1397506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1398506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1399506f1d07SSam Ravnborg possible. 1400506f1d07SSam Ravnborg 1401506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1402506f1d07SSam Ravnborg answer "4GB" here. 1403506f1d07SSam Ravnborg 1404506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1405506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1406506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1407506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1408506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1409506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1410506f1d07SSam Ravnborg 1411506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1412506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1413506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1414506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1415506f1d07SSam Ravnborg kernel at boot time.) 1416506f1d07SSam Ravnborg 1417506f1d07SSam Ravnborg If unsure, say "off". 1418506f1d07SSam Ravnborg 1419506f1d07SSam Ravnborgconfig HIGHMEM4G 1420506f1d07SSam Ravnborg bool "4GB" 1421a7f7f624SMasahiro Yamada help 1422506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1423506f1d07SSam Ravnborg gigabytes of physical RAM. 1424506f1d07SSam Ravnborg 1425506f1d07SSam Ravnborgconfig HIGHMEM64G 1426506f1d07SSam Ravnborg bool "64GB" 1427225bac2dSLukas Bulwahn depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6 1428506f1d07SSam Ravnborg select X86_PAE 1429a7f7f624SMasahiro Yamada help 1430506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1431506f1d07SSam Ravnborg gigabytes of physical RAM. 1432506f1d07SSam Ravnborg 1433506f1d07SSam Ravnborgendchoice 1434506f1d07SSam Ravnborg 1435506f1d07SSam Ravnborgchoice 14366a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1437506f1d07SSam Ravnborg default VMSPLIT_3G 1438506f1d07SSam Ravnborg depends on X86_32 1439a7f7f624SMasahiro Yamada help 1440506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1441506f1d07SSam Ravnborg 1442506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1443506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1444506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1445506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1446506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1447506f1d07SSam Ravnborg available to user programs, making the address space there 1448506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1449506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1450506f1d07SSam Ravnborg kernel modules. 1451506f1d07SSam Ravnborg 1452506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1453506f1d07SSam Ravnborg option alone! 1454506f1d07SSam Ravnborg 1455506f1d07SSam Ravnborg config VMSPLIT_3G 1456506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1457506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1458506f1d07SSam Ravnborg depends on !X86_PAE 1459506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1460506f1d07SSam Ravnborg config VMSPLIT_2G 1461506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1462506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1463506f1d07SSam Ravnborg depends on !X86_PAE 1464506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1465506f1d07SSam Ravnborg config VMSPLIT_1G 1466506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1467506f1d07SSam Ravnborgendchoice 1468506f1d07SSam Ravnborg 1469506f1d07SSam Ravnborgconfig PAGE_OFFSET 1470506f1d07SSam Ravnborg hex 1471506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1472506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1473506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1474506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1475506f1d07SSam Ravnborg default 0xC0000000 1476506f1d07SSam Ravnborg depends on X86_32 1477506f1d07SSam Ravnborg 1478506f1d07SSam Ravnborgconfig HIGHMEM 14793c2362e6SHarvey Harrison def_bool y 1480506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1481506f1d07SSam Ravnborg 1482506f1d07SSam Ravnborgconfig X86_PAE 14839ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1484506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 1485d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 14869d99c712SChristian Melki select SWIOTLB 1487a7f7f624SMasahiro Yamada help 1488506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1489506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1490506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1491506f1d07SSam Ravnborg consumes more pagetable space per process. 1492506f1d07SSam Ravnborg 149377ef56e4SKirill A. Shutemovconfig X86_5LEVEL 149477ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 149518ec1eafSKirill A. Shutemov default y 1496eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1497162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 149877ef56e4SKirill A. Shutemov depends on X86_64 1499a7f7f624SMasahiro Yamada help 150077ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 150177ef56e4SKirill A. Shutemov up to 128 PiB of virtual address space and 4 PiB of 150277ef56e4SKirill A. Shutemov physical address space. 150377ef56e4SKirill A. Shutemov 150477ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 150577ef56e4SKirill A. Shutemov 15066657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 15076657fca0SKirill A. Shutemov support 4- or 5-level paging. 150877ef56e4SKirill A. Shutemov 1509ff61f079SJonathan Corbet See Documentation/arch/x86/x86_64/5level-paging.rst for more 151077ef56e4SKirill A. Shutemov information. 151177ef56e4SKirill A. Shutemov 151277ef56e4SKirill A. Shutemov Say N if unsure. 151377ef56e4SKirill A. Shutemov 151410971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1515e5008abeSLuis R. Rodriguez def_bool y 15162e1da13fSVlastimil Babka depends on X86_64 1517a7f7f624SMasahiro Yamada help 151810971ab2SIngo Molnar Certain kernel features effectively disable kernel 151910971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 152010971ab2SIngo Molnar supports them), so don't confuse the user by printing 152110971ab2SIngo Molnar that we have them enabled. 15229e899816SNick Piggin 15235c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15245c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15255c280cf6SThomas Gleixner depends on DEBUG_FS 1526a7f7f624SMasahiro Yamada help 1527b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1528a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15295c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15305c280cf6SThomas Gleixner 153120f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT 153220f07a04SKirill A. Shutemov select ARCH_HAS_FORCE_DMA_UNENCRYPTED 153320f07a04SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 153420f07a04SKirill A. Shutemov def_bool n 153520f07a04SKirill A. Shutemov 15367744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15377744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15387744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 15396c321179STom Lendacky depends on EFI_STUB 154082fef0adSDavid Rientjes select DMA_COHERENT_POOL 1541ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 1542597cfe48SJoerg Roedel select INSTRUCTION_DECODER 1543aa5a4611STom Lendacky select ARCH_HAS_CC_PLATFORM 154420f07a04SKirill A. Shutemov select X86_MEM_ENCRYPT 15456c321179STom Lendacky select UNACCEPTED_MEMORY 1546a7f7f624SMasahiro Yamada help 15477744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15487744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15497744ccdbSTom Lendacky Encryption (SME). 15507744ccdbSTom Lendacky 15517744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 15527744ccdbSTom Lendacky bool "Activate AMD Secure Memory Encryption (SME) by default" 15537744ccdbSTom Lendacky depends on AMD_MEM_ENCRYPT 1554a7f7f624SMasahiro Yamada help 15557744ccdbSTom Lendacky Say yes to have system memory encrypted by default if running on 15567744ccdbSTom Lendacky an AMD processor that supports Secure Memory Encryption (SME). 15577744ccdbSTom Lendacky 15587744ccdbSTom Lendacky If set to Y, then the encryption of system memory can be 15597744ccdbSTom Lendacky deactivated with the mem_encrypt=off command line option. 15607744ccdbSTom Lendacky 15617744ccdbSTom Lendacky If set to N, then the encryption of system memory can be 15627744ccdbSTom Lendacky activated with the mem_encrypt=on command line option. 15637744ccdbSTom Lendacky 1564506f1d07SSam Ravnborg# Common NUMA Features 1565506f1d07SSam Ravnborgconfig NUMA 1566e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1567506f1d07SSam Ravnborg depends on SMP 1568b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1569b5660ba7SH. Peter Anvin default y if X86_BIGSMP 15707ecd19cfSKefeng Wang select USE_PERCPU_NUMA_NODE_ID 1571a7f7f624SMasahiro Yamada help 1572e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1573fd51b2d7SKOSAKI Motohiro 1574506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1575506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1576506f1d07SSam Ravnborg NUMA awareness to the kernel. 1577506f1d07SSam Ravnborg 1578c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1579fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1580fd51b2d7SKOSAKI Motohiro 1581b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 15827cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1583fd51b2d7SKOSAKI Motohiro 1584fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1585506f1d07SSam Ravnborg 1586eec1d4faSHans Rosenfeldconfig AMD_NUMA 15873c2362e6SHarvey Harrison def_bool y 15883c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15895da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1590a7f7f624SMasahiro Yamada help 1591eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1592eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1593eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1594eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1595eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1596506f1d07SSam Ravnborg 1597506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 15983c2362e6SHarvey Harrison def_bool y 15993c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1600506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1601506f1d07SSam Ravnborg select ACPI_NUMA 1602a7f7f624SMasahiro Yamada help 1603506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1604506f1d07SSam Ravnborg 1605506f1d07SSam Ravnborgconfig NUMA_EMU 1606506f1d07SSam Ravnborg bool "NUMA emulation" 16071b7e03efSTejun Heo depends on NUMA 1608a7f7f624SMasahiro Yamada help 1609506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1610506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1611506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1612506f1d07SSam Ravnborg 1613506f1d07SSam Ravnborgconfig NODES_SHIFT 1614d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 161551591e31SDavid Rientjes range 1 10 161651591e31SDavid Rientjes default "10" if MAXSMP 1617506f1d07SSam Ravnborg default "6" if X86_64 1618506f1d07SSam Ravnborg default "3" 1619a9ee6cf5SMike Rapoport depends on NUMA 1620a7f7f624SMasahiro Yamada help 16211184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1622692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1623506f1d07SSam Ravnborg 1624506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1625506f1d07SSam Ravnborg def_bool y 16263b16651fSTejun Heo depends on X86_32 && !NUMA 1627506f1d07SSam Ravnborg 1628506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1629506f1d07SSam Ravnborg def_bool y 16306ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1631506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1632506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1633506f1d07SSam Ravnborg 16343b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 16356ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 16363b16651fSTejun Heo 1637506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1638506f1d07SSam Ravnborg def_bool y 16394eda2bc3SDavid Hildenbrand depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE 1640506f1d07SSam Ravnborg 1641506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1642a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16435c11f00bSDavid Hildenbrand depends on MEMORY_HOTPLUG 1644a0842b70SToshi Kani help 1645a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1646cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1647a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1648506f1d07SSam Ravnborg 16493b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16503b16651fSTejun Heo def_bool y 16513b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16523b16651fSTejun Heo 1653a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1654a29815a3SAvi Kivity hex 1655a29815a3SAvi Kivity default 0 if X86_32 1656a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1657a29815a3SAvi Kivity 16587a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16597a67832cSDan Williams bool 16607a67832cSDan Williams 1661ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16627a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16639f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16649f53f9faSDan Williams depends on BLK_DEV 16657a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16667b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16679f53f9faSDan Williams select LIBNVDIMM 1668ec776ef6SChristoph Hellwig help 1669ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1670ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1671ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1672ec776ef6SChristoph Hellwig they can be used for persistent storage. 1673ec776ef6SChristoph Hellwig 1674ec776ef6SChristoph Hellwig Say Y if unsure. 1675ec776ef6SChristoph Hellwig 1676506f1d07SSam Ravnborgconfig HIGHPTE 1677506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 16786fc108a0SJan Beulich depends on HIGHMEM 1679a7f7f624SMasahiro Yamada help 1680506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1681506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1682506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1683506f1d07SSam Ravnborg entries in high memory. 1684506f1d07SSam Ravnborg 16859f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16869f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1687a7f7f624SMasahiro Yamada help 16889f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16899f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16909f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 16919f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 16929f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 16939f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 16949f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 16958c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 16969f077871SJeremy Fitzhardinge 16979f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 16989f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 16999f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 17009f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 17019f077871SJeremy Fitzhardinge 17029f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 17039f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 17049f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 17059f077871SJeremy Fitzhardinge memory. 17069f077871SJeremy Fitzhardinge 1707c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1708c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1709c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1710c885df50SJeremy Fitzhardinge default y 1711a7f7f624SMasahiro Yamada help 1712c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1713c885df50SJeremy Fitzhardinge on or off. 1714c885df50SJeremy Fitzhardinge 1715506f1d07SSam Ravnborgconfig MATH_EMULATION 1716506f1d07SSam Ravnborg bool 1717a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 171887d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1719a7f7f624SMasahiro Yamada help 1720506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1721506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1722506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1723506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1724506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1725506f1d07SSam Ravnborg coprocessor or this emulation. 1726506f1d07SSam Ravnborg 1727506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1728506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1729506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1730506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1731506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1732506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1733506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1734506f1d07SSam Ravnborg intend to use this kernel on different machines. 1735506f1d07SSam Ravnborg 1736506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1737506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1738506f1d07SSam Ravnborg 1739506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1740506f1d07SSam Ravnborg kernel, it won't hurt. 1741506f1d07SSam Ravnborg 1742506f1d07SSam Ravnborgconfig MTRR 17436fc108a0SJan Beulich def_bool y 17446a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1745a7f7f624SMasahiro Yamada help 1746506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1747506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1748506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1749506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1750506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1751506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1752506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1753506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1754506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1755506f1d07SSam Ravnborg 1756506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1757506f1d07SSam Ravnborg control registers on other processors can be easily supported 1758506f1d07SSam Ravnborg as well: 1759506f1d07SSam Ravnborg 1760506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1761506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1762506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1763506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1764506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1765506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1766506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1767506f1d07SSam Ravnborg 1768506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1769506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1770506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1771506f1d07SSam Ravnborg 1772506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1773506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1774506f1d07SSam Ravnborg 1775ff61f079SJonathan Corbet See <file:Documentation/arch/x86/mtrr.rst> for more information. 1776506f1d07SSam Ravnborg 177795ffa243SYinghai Luconfig MTRR_SANITIZER 17782ffb3501SYinghai Lu def_bool y 177995ffa243SYinghai Lu prompt "MTRR cleanup support" 178095ffa243SYinghai Lu depends on MTRR 1781a7f7f624SMasahiro Yamada help 1782aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1783aba3728cSThomas Gleixner add writeback entries. 178495ffa243SYinghai Lu 1785aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1786692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1787aba3728cSThomas Gleixner mtrr_chunk_size. 178895ffa243SYinghai Lu 17892ffb3501SYinghai Lu If unsure, say Y. 179095ffa243SYinghai Lu 179195ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1792f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1793f5098d62SYinghai Lu range 0 1 1794f5098d62SYinghai Lu default "0" 179595ffa243SYinghai Lu depends on MTRR_SANITIZER 1796a7f7f624SMasahiro Yamada help 1797f5098d62SYinghai Lu Enable mtrr cleanup default value 179895ffa243SYinghai Lu 179912031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 180012031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 180112031a62SYinghai Lu range 0 7 180212031a62SYinghai Lu default "1" 180312031a62SYinghai Lu depends on MTRR_SANITIZER 1804a7f7f624SMasahiro Yamada help 180512031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1806aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 180712031a62SYinghai Lu 18082e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 18096fc108a0SJan Beulich def_bool y 18106a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 18112a8a2719SIngo Molnar depends on MTRR 1812a7f7f624SMasahiro Yamada help 18132e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1814042b78e4SVenki Pallipadi 18152e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 18162e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 18172e5d9c85Svenkatesh.pallipadi@intel.com 18182e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1819042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 18202e5d9c85Svenkatesh.pallipadi@intel.com 18212e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 18222e5d9c85Svenkatesh.pallipadi@intel.com 182346cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 182446cf98cdSVenkatesh Pallipadi def_bool y 182546cf98cdSVenkatesh Pallipadi depends on X86_PAT 182646cf98cdSVenkatesh Pallipadi 1827b971880fSBabu Mogerconfig X86_UMIP 1828796ebc81SRicardo Neri def_bool y 1829b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1830a7f7f624SMasahiro Yamada help 1831b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1832b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1833b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1834b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1835b971880fSBabu Moger information about the hardware state. 1836796ebc81SRicardo Neri 1837796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1838796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1839796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1840796ebc81SRicardo Neri results are dummy. 1841aa35f896SRicardo Neri 1842156ff4a5SPeter Zijlstraconfig CC_HAS_IBT 1843156ff4a5SPeter Zijlstra # GCC >= 9 and binutils >= 2.29 1844156ff4a5SPeter Zijlstra # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 1845156ff4a5SPeter Zijlstra # Clang/LLVM >= 14 1846262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f 1847262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 1848156ff4a5SPeter Zijlstra def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ 1849262448f3SNathan Chancellor (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ 1850156ff4a5SPeter Zijlstra $(as-instr,endbr64) 1851156ff4a5SPeter Zijlstra 1852156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT 1853156ff4a5SPeter Zijlstra prompt "Indirect Branch Tracking" 18544fd5f70cSKees Cook def_bool y 185503f16cd0SJosh Poimboeuf depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL 1856f6a2c2b2SNathan Chancellor # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f 1857f6a2c2b2SNathan Chancellor depends on !LD_IS_LLD || LLD_VERSION >= 140000 185803f16cd0SJosh Poimboeuf select OBJTOOL 1859156ff4a5SPeter Zijlstra help 1860156ff4a5SPeter Zijlstra Build the kernel with support for Indirect Branch Tracking, a 1861156ff4a5SPeter Zijlstra hardware support course-grain forward-edge Control Flow Integrity 1862156ff4a5SPeter Zijlstra protection. It enforces that all indirect calls must land on 1863156ff4a5SPeter Zijlstra an ENDBR instruction, as such, the compiler will instrument the 1864156ff4a5SPeter Zijlstra code with them to make this happen. 1865156ff4a5SPeter Zijlstra 1866ed53a0d9SPeter Zijlstra In addition to building the kernel with IBT, seal all functions that 18674cdfc11bSNur Hussein are not indirect call targets, avoiding them ever becoming one. 1868ed53a0d9SPeter Zijlstra 1869ed53a0d9SPeter Zijlstra This requires LTO like objtool runs and will slow down the build. It 1870ed53a0d9SPeter Zijlstra does significantly reduce the number of ENDBR instructions in the 1871ed53a0d9SPeter Zijlstra kernel image. 1872ed53a0d9SPeter Zijlstra 187335e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS 187438f3e775SBabu Moger prompt "Memory Protection Keys" 187535e97790SDave Hansen def_bool y 1876284244a9SDave Hansen # Note: only available in 64-bit mode 187738f3e775SBabu Moger depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 187852c8e601SIngo Molnar select ARCH_USES_HIGH_VMA_FLAGS 187952c8e601SIngo Molnar select ARCH_HAS_PKEYS 1880a7f7f624SMasahiro Yamada help 1881284244a9SDave Hansen Memory Protection Keys provides a mechanism for enforcing 1882284244a9SDave Hansen page-based protections, but without requiring modification of the 1883284244a9SDave Hansen page tables when an application changes protection domains. 1884284244a9SDave Hansen 18851eecbcdcSMauro Carvalho Chehab For details, see Documentation/core-api/protection-keys.rst 1886284244a9SDave Hansen 1887284244a9SDave Hansen If unsure, say y. 188835e97790SDave Hansen 1889db616173SMichal Hockochoice 1890db616173SMichal Hocko prompt "TSX enable mode" 1891db616173SMichal Hocko depends on CPU_SUP_INTEL 1892db616173SMichal Hocko default X86_INTEL_TSX_MODE_OFF 1893db616173SMichal Hocko help 1894db616173SMichal Hocko Intel's TSX (Transactional Synchronization Extensions) feature 1895db616173SMichal Hocko allows to optimize locking protocols through lock elision which 1896db616173SMichal Hocko can lead to a noticeable performance boost. 1897db616173SMichal Hocko 1898db616173SMichal Hocko On the other hand it has been shown that TSX can be exploited 1899db616173SMichal Hocko to form side channel attacks (e.g. TAA) and chances are there 1900db616173SMichal Hocko will be more of those attacks discovered in the future. 1901db616173SMichal Hocko 1902db616173SMichal Hocko Therefore TSX is not enabled by default (aka tsx=off). An admin 1903db616173SMichal Hocko might override this decision by tsx=on the command line parameter. 1904db616173SMichal Hocko Even with TSX enabled, the kernel will attempt to enable the best 1905db616173SMichal Hocko possible TAA mitigation setting depending on the microcode available 1906db616173SMichal Hocko for the particular machine. 1907db616173SMichal Hocko 1908db616173SMichal Hocko This option allows to set the default tsx mode between tsx=on, =off 1909db616173SMichal Hocko and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1910db616173SMichal Hocko details. 1911db616173SMichal Hocko 1912db616173SMichal Hocko Say off if not sure, auto if TSX is in use but it should be used on safe 1913db616173SMichal Hocko platforms or on if TSX is in use and the security aspect of tsx is not 1914db616173SMichal Hocko relevant. 1915db616173SMichal Hocko 1916db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF 1917db616173SMichal Hocko bool "off" 1918db616173SMichal Hocko help 1919db616173SMichal Hocko TSX is disabled if possible - equals to tsx=off command line parameter. 1920db616173SMichal Hocko 1921db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON 1922db616173SMichal Hocko bool "on" 1923db616173SMichal Hocko help 1924db616173SMichal Hocko TSX is always enabled on TSX capable HW - equals the tsx=on command 1925db616173SMichal Hocko line parameter. 1926db616173SMichal Hocko 1927db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO 1928db616173SMichal Hocko bool "auto" 1929db616173SMichal Hocko help 1930db616173SMichal Hocko TSX is enabled on TSX capable HW that is believed to be safe against 1931db616173SMichal Hocko side channel attacks- equals the tsx=auto command line parameter. 1932db616173SMichal Hockoendchoice 1933db616173SMichal Hocko 1934e7e05452SSean Christophersonconfig X86_SGX 1935e7e05452SSean Christopherson bool "Software Guard eXtensions (SGX)" 1936b8d1d163SDaniel Sneddon depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC 1937e7e05452SSean Christopherson depends on CRYPTO=y 1938e7e05452SSean Christopherson depends on CRYPTO_SHA256=y 1939e7e05452SSean Christopherson select MMU_NOTIFIER 1940901ddbb9SJarkko Sakkinen select NUMA_KEEP_MEMINFO if NUMA 194140e0e784STony Luck select XARRAY_MULTI 1942e7e05452SSean Christopherson help 1943e7e05452SSean Christopherson Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1944e7e05452SSean Christopherson that can be used by applications to set aside private regions of code 1945e7e05452SSean Christopherson and data, referred to as enclaves. An enclave's private memory can 1946e7e05452SSean Christopherson only be accessed by code running within the enclave. Accesses from 1947e7e05452SSean Christopherson outside the enclave, including other enclaves, are disallowed by 1948e7e05452SSean Christopherson hardware. 1949e7e05452SSean Christopherson 1950e7e05452SSean Christopherson If unsure, say N. 1951e7e05452SSean Christopherson 1952506f1d07SSam Ravnborgconfig EFI 19539ba16087SJan Beulich bool "EFI runtime service support" 19545b83683fSHuang, Ying depends on ACPI 1955f6ce5002SSergey Vlasov select UCS2_STRING 1956022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 19571ff2fc02STom Lendacky select ARCH_USE_MEMREMAP_PROT 1958a7f7f624SMasahiro Yamada help 19598b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1960506f1d07SSam Ravnborg available (such as the EFI variable services). 1961506f1d07SSam Ravnborg 19628b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19638b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19648b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19658b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19668b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19678b2cb7a8SHuang, Ying platforms. 1968506f1d07SSam Ravnborg 1969291f3632SMatt Flemingconfig EFI_STUB 1970291f3632SMatt Fleming bool "EFI stub support" 1971c6dbd3e5SPeter Zijlstra depends on EFI 19727b2a583aSMatt Fleming select RELOCATABLE 1973a7f7f624SMasahiro Yamada help 1974291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 1975291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 1976291f3632SMatt Fleming 19774f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 19780c759662SMatt Fleming 1979cc3fdda2SArd Biesheuvelconfig EFI_HANDOVER_PROTOCOL 1980cc3fdda2SArd Biesheuvel bool "EFI handover protocol (DEPRECATED)" 1981cc3fdda2SArd Biesheuvel depends on EFI_STUB 1982cc3fdda2SArd Biesheuvel default y 1983cc3fdda2SArd Biesheuvel help 1984cc3fdda2SArd Biesheuvel Select this in order to include support for the deprecated EFI 1985cc3fdda2SArd Biesheuvel handover protocol, which defines alternative entry points into the 1986cc3fdda2SArd Biesheuvel EFI stub. This is a practice that has no basis in the UEFI 1987cc3fdda2SArd Biesheuvel specification, and requires a priori knowledge on the part of the 1988cc3fdda2SArd Biesheuvel bootloader about Linux/x86 specific ways of passing the command line 1989cc3fdda2SArd Biesheuvel and initrd, and where in memory those assets may be loaded. 1990cc3fdda2SArd Biesheuvel 1991cc3fdda2SArd Biesheuvel If in doubt, say Y. Even though the corresponding support is not 1992cc3fdda2SArd Biesheuvel present in upstream GRUB or other bootloaders, most distros build 1993cc3fdda2SArd Biesheuvel GRUB with numerous downstream patches applied, and may rely on the 1994cc3fdda2SArd Biesheuvel handover protocol as as result. 1995cc3fdda2SArd Biesheuvel 19967d453eeeSMatt Flemingconfig EFI_MIXED 19977d453eeeSMatt Fleming bool "EFI mixed-mode support" 19987d453eeeSMatt Fleming depends on EFI_STUB && X86_64 1999a7f7f624SMasahiro Yamada help 20007d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 20017d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 20027d453eeeSMatt Fleming mode. 20037d453eeeSMatt Fleming 20047d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 20057d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 20067d453eeeSMatt Fleming the EFI handover protocol must be used. 20077d453eeeSMatt Fleming 20087d453eeeSMatt Fleming If unsure, say N. 20097d453eeeSMatt Fleming 20104059ba65SArd Biesheuvelconfig EFI_FAKE_MEMMAP 20114059ba65SArd Biesheuvel bool "Enable EFI fake memory map" 20124059ba65SArd Biesheuvel depends on EFI 20134059ba65SArd Biesheuvel help 20144059ba65SArd Biesheuvel Saying Y here will enable "efi_fake_mem" boot option. By specifying 20154059ba65SArd Biesheuvel this parameter, you can add arbitrary attribute to specific memory 20164059ba65SArd Biesheuvel range by updating original (firmware provided) EFI memmap. This is 20174059ba65SArd Biesheuvel useful for debugging of EFI memmap related feature, e.g., Address 20184059ba65SArd Biesheuvel Range Mirroring feature. 20194059ba65SArd Biesheuvel 20204059ba65SArd Biesheuvelconfig EFI_MAX_FAKE_MEM 20214059ba65SArd Biesheuvel int "maximum allowable number of ranges in efi_fake_mem boot option" 20224059ba65SArd Biesheuvel depends on EFI_FAKE_MEMMAP 20234059ba65SArd Biesheuvel range 1 128 20244059ba65SArd Biesheuvel default 8 20254059ba65SArd Biesheuvel help 20264059ba65SArd Biesheuvel Maximum allowable number of ranges in efi_fake_mem boot option. 20274059ba65SArd Biesheuvel Ranges can be set up to this value using comma-separated list. 20284059ba65SArd Biesheuvel The default value is 8. 20294059ba65SArd Biesheuvel 20301fff234dSArd Biesheuvelconfig EFI_RUNTIME_MAP 20311fff234dSArd Biesheuvel bool "Export EFI runtime maps to sysfs" if EXPERT 20321fff234dSArd Biesheuvel depends on EFI 20331fff234dSArd Biesheuvel default KEXEC_CORE 20341fff234dSArd Biesheuvel help 20351fff234dSArd Biesheuvel Export EFI runtime memory regions to /sys/firmware/efi/runtime-map. 20361fff234dSArd Biesheuvel That memory map is required by the 2nd kernel to set up EFI virtual 20371fff234dSArd Biesheuvel mappings after kexec, but can also be used for debugging purposes. 20381fff234dSArd Biesheuvel 20391fff234dSArd Biesheuvel See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map. 20401fff234dSArd Biesheuvel 20418636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 2042506f1d07SSam Ravnborg 2043506f1d07SSam Ravnborgconfig KEXEC 2044506f1d07SSam Ravnborg bool "kexec system call" 20452965faa5SDave Young select KEXEC_CORE 2046a7f7f624SMasahiro Yamada help 2047506f1d07SSam Ravnborg kexec is a system call that implements the ability to shutdown your 2048506f1d07SSam Ravnborg current kernel, and to start another kernel. It is like a reboot 2049506f1d07SSam Ravnborg but it is independent of the system firmware. And like a reboot 2050506f1d07SSam Ravnborg you can start any kernel with it, not just Linux. 2051506f1d07SSam Ravnborg 2052506f1d07SSam Ravnborg The name comes from the similarity to the exec system call. 2053506f1d07SSam Ravnborg 2054506f1d07SSam Ravnborg It is an ongoing process to be certain the hardware in a machine 2055506f1d07SSam Ravnborg is properly shutdown, so do not be surprised if this code does not 2056bf220695SGeert Uytterhoeven initially work for you. As of this writing the exact hardware 2057bf220695SGeert Uytterhoeven interface is strongly in flux, so no good recommendation can be 2058bf220695SGeert Uytterhoeven made. 2059506f1d07SSam Ravnborg 206074ca317cSVivek Goyalconfig KEXEC_FILE 206174ca317cSVivek Goyal bool "kexec file based system call" 20622965faa5SDave Young select KEXEC_CORE 2063b69a2afdSJonathan McDowell select HAVE_IMA_KEXEC if IMA 206474ca317cSVivek Goyal depends on X86_64 206574ca317cSVivek Goyal depends on CRYPTO=y 206674ca317cSVivek Goyal depends on CRYPTO_SHA256=y 2067a7f7f624SMasahiro Yamada help 206874ca317cSVivek Goyal This is new version of kexec system call. This system call is 206974ca317cSVivek Goyal file based and takes file descriptors as system call argument 207074ca317cSVivek Goyal for kernel and initramfs as opposed to list of segments as 207174ca317cSVivek Goyal accepted by previous system call. 207274ca317cSVivek Goyal 2073b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY 2074b799a09fSAKASHI Takahiro def_bool KEXEC_FILE 2075b799a09fSAKASHI Takahiro 207699d5cadfSJiri Bohacconfig KEXEC_SIG 20778e7d8381SVivek Goyal bool "Verify kernel signature during kexec_file_load() syscall" 207874ca317cSVivek Goyal depends on KEXEC_FILE 2079a7f7f624SMasahiro Yamada help 208099d5cadfSJiri Bohac 208199d5cadfSJiri Bohac This option makes the kexec_file_load() syscall check for a valid 208299d5cadfSJiri Bohac signature of the kernel image. The image can still be loaded without 208399d5cadfSJiri Bohac a valid signature unless you also enable KEXEC_SIG_FORCE, though if 208499d5cadfSJiri Bohac there's a signature that we can check, then it must be valid. 208599d5cadfSJiri Bohac 208699d5cadfSJiri Bohac In addition to this option, you need to enable signature 208799d5cadfSJiri Bohac verification for the corresponding kernel image type being 208899d5cadfSJiri Bohac loaded in order for this to work. 208999d5cadfSJiri Bohac 209099d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE 209199d5cadfSJiri Bohac bool "Require a valid signature in kexec_file_load() syscall" 209299d5cadfSJiri Bohac depends on KEXEC_SIG 2093a7f7f624SMasahiro Yamada help 20948e7d8381SVivek Goyal This option makes kernel signature verification mandatory for 2095d8eb8940SBorislav Petkov the kexec_file_load() syscall. 20968e7d8381SVivek Goyal 20978e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG 20988e7d8381SVivek Goyal bool "Enable bzImage signature verification support" 209999d5cadfSJiri Bohac depends on KEXEC_SIG 21008e7d8381SVivek Goyal depends on SIGNED_PE_FILE_VERIFICATION 21018e7d8381SVivek Goyal select SYSTEM_TRUSTED_KEYRING 2102a7f7f624SMasahiro Yamada help 21038e7d8381SVivek Goyal Enable bzImage signature verification support. 21048e7d8381SVivek Goyal 2105506f1d07SSam Ravnborgconfig CRASH_DUMP 210604b69447SPavel Machek bool "kernel crash dumps" 2107506f1d07SSam Ravnborg depends on X86_64 || (X86_32 && HIGHMEM) 2108a7f7f624SMasahiro Yamada help 2109506f1d07SSam Ravnborg Generate crash dump after being started by kexec. 2110506f1d07SSam Ravnborg This should be normally only set in special crash dump kernels 2111506f1d07SSam Ravnborg which are loaded in the main kernel with kexec-tools into 2112506f1d07SSam Ravnborg a specially reserved region and then later executed after 2113506f1d07SSam Ravnborg a crash by kdump/kexec. The crash dump kernel must be compiled 2114506f1d07SSam Ravnborg to a memory address not used by the main kernel or BIOS using 2115506f1d07SSam Ravnborg PHYSICAL_START, or it must be built as a relocatable image 2116506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y). 2117330d4810SMauro Carvalho Chehab For more details see Documentation/admin-guide/kdump/kdump.rst 2118506f1d07SSam Ravnborg 21193ab83521SHuang Yingconfig KEXEC_JUMP 21206ea30386SKees Cook bool "kexec jump" 2121fee7b0d8SHuang Ying depends on KEXEC && HIBERNATION 2122a7f7f624SMasahiro Yamada help 212389081d17SHuang Ying Jump between original kernel and kexeced kernel and invoke 212489081d17SHuang Ying code in physical address mode via KEXEC 21253ab83521SHuang Ying 2126506f1d07SSam Ravnborgconfig PHYSICAL_START 21276a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2128ceefccc9SH. Peter Anvin default "0x1000000" 2129a7f7f624SMasahiro Yamada help 2130506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2131506f1d07SSam Ravnborg 2132506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2133506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 2134506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 2135506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 2136506f1d07SSam Ravnborg address. 2137506f1d07SSam Ravnborg 2138506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2139506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2140506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2141506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2142506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2143506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2144506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2145506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2146506f1d07SSam Ravnborg 2147ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2148ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2149ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2150ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2151ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2152ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2153ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2154330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2155ceefccc9SH. Peter Anvin for more details about crash dumps. 2156506f1d07SSam Ravnborg 2157506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2158506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2159506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2160506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2161506f1d07SSam Ravnborg is present because there are users out there who continue to use 2162506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2163506f1d07SSam Ravnborg line. 2164506f1d07SSam Ravnborg 2165506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2166506f1d07SSam Ravnborg 2167506f1d07SSam Ravnborgconfig RELOCATABLE 216826717808SH. Peter Anvin bool "Build a relocatable kernel" 216926717808SH. Peter Anvin default y 2170a7f7f624SMasahiro Yamada help 2171506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2172506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2173506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2174506f1d07SSam Ravnborg but are discarded at runtime. 2175506f1d07SSam Ravnborg 2176506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2177506f1d07SSam Ravnborg must live at a different physical address than the primary 2178506f1d07SSam Ravnborg kernel. 2179506f1d07SSam Ravnborg 2180506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2181506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 21828ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2183506f1d07SSam Ravnborg 21848ab3820fSKees Cookconfig RANDOMIZE_BASE 2185e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21868ab3820fSKees Cook depends on RELOCATABLE 21876807c846SIngo Molnar default y 2188a7f7f624SMasahiro Yamada help 2189e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2190e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2191e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2192e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2193e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2194e8581e3dSBaoquan He code internals. 2195e8581e3dSBaoquan He 2196ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2197ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2198ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2199ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2200ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2201ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2202ed9f007eSKees Cook 2203ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2204ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2205ed9f007eSKees Cook 512MB (8 bits of entropy). 22068ab3820fSKees Cook 2207a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2208e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2209e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2210ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2211ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2212ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2213ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2214ed9f007eSKees Cook theoretically possible, but the implementations are further 2215ed9f007eSKees Cook limited due to memory layouts. 2216e8581e3dSBaoquan He 22176807c846SIngo Molnar If unsure, say Y. 2218da2b6fb9SKees Cook 22198ab3820fSKees Cook# Relocation on x86 needs some additional build support 2220845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2221845adf72SH. Peter Anvin def_bool y 22228ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2223845adf72SH. Peter Anvin 2224506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2225a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 22268ab3820fSKees Cook default "0x200000" 2227a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2228a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2229a7f7f624SMasahiro Yamada help 2230506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2231506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2232506f1d07SSam Ravnborg address which meets above alignment restriction. 2233506f1d07SSam Ravnborg 2234506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2235506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2236506f1d07SSam Ravnborg address aligned to above value and run from there. 2237506f1d07SSam Ravnborg 2238506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2239506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2240506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2241506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2242506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2243506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2244506f1d07SSam Ravnborg above alignment restrictions. 2245506f1d07SSam Ravnborg 2246a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2247a0215061SKees Cook this value must be a multiple of 0x200000. 2248a0215061SKees Cook 2249506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2250506f1d07SSam Ravnborg 2251eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2252eedb92abSKirill A. Shutemov bool 2253a7f7f624SMasahiro Yamada help 2254eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2255eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2256eedb92abSKirill A. Shutemov 22570483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 22580483e1faSThomas Garnier bool "Randomize the kernel memory sections" 22590483e1faSThomas Garnier depends on X86_64 22600483e1faSThomas Garnier depends on RANDOMIZE_BASE 2261eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 22620483e1faSThomas Garnier default RANDOMIZE_BASE 2263a7f7f624SMasahiro Yamada help 22640483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 22650483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 22660483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 22670483e1faSThomas Garnier 22680483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 22690483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 22700483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 22710483e1faSThomas Garnier addresses for each memory section. 22720483e1faSThomas Garnier 22736807c846SIngo Molnar If unsure, say Y. 22740483e1faSThomas Garnier 227590397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 227690397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 227790397a41SThomas Garnier depends on RANDOMIZE_MEMORY 227890397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 227990397a41SThomas Garnier default "0x0" 228090397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 228190397a41SThomas Garnier range 0x0 0x40 2282a7f7f624SMasahiro Yamada help 228390397a41SThomas Garnier Define the padding in terabytes added to the existing physical 228490397a41SThomas Garnier memory size during kernel memory randomization. It is useful 228590397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 228690397a41SThomas Garnier address randomization. 228790397a41SThomas Garnier 228890397a41SThomas Garnier If unsure, leave at the default value. 228990397a41SThomas Garnier 22906449dcb0SKirill A. Shutemovconfig ADDRESS_MASKING 22916449dcb0SKirill A. Shutemov bool "Linear Address Masking support" 22926449dcb0SKirill A. Shutemov depends on X86_64 22936449dcb0SKirill A. Shutemov help 22946449dcb0SKirill A. Shutemov Linear Address Masking (LAM) modifies the checking that is applied 22956449dcb0SKirill A. Shutemov to 64-bit linear addresses, allowing software to use of the 22966449dcb0SKirill A. Shutemov untranslated address bits for metadata. 22976449dcb0SKirill A. Shutemov 22986449dcb0SKirill A. Shutemov The capability can be used for efficient address sanitizers (ASAN) 22996449dcb0SKirill A. Shutemov implementation and for optimizations in JITs. 23006449dcb0SKirill A. Shutemov 2301506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2302bebd024eSThomas Gleixner def_bool y 230340b31360SStephen Rothwell depends on SMP 2304506f1d07SSam Ravnborg 2305506f1d07SSam Ravnborgconfig COMPAT_VDSO 2306b0b49f26SAndy Lutomirski def_bool n 2307b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2308953fee1dSIngo Molnar depends on COMPAT_32 2309a7f7f624SMasahiro Yamada help 2310b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2311b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2312b0b49f26SAndy Lutomirski indicated in its segment table. 2313e84446deSRandy Dunlap 2314b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2315b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2316b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2317b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2318b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2319506f1d07SSam Ravnborg 2320b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2321b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2322b0b49f26SAndy Lutomirski 2323b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2324b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2325b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2326b0b49f26SAndy Lutomirski 2327b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2328b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2329506f1d07SSam Ravnborg 23303dc33bd3SKees Cookchoice 23313dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 23323dc33bd3SKees Cook depends on X86_64 2333625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 23343dc33bd3SKees Cook help 23353dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 23363dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 23373dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 23383dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 23393dc33bd3SKees Cook 23403dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2341bf00745eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. Emulate mode 2342bf00745eSAndy Lutomirski is deprecated and can only be enabled using the kernel command 2343bf00745eSAndy Lutomirski line. 23443dc33bd3SKees Cook 23453dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 23463dc33bd3SKees Cook static binaries, you can say None without a performance penalty 23473dc33bd3SKees Cook to improve security. 23483dc33bd3SKees Cook 2349bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 23503dc33bd3SKees Cook 2351bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2352bd49e16eSAndy Lutomirski bool "Emulate execution only" 2353bd49e16eSAndy Lutomirski help 2354bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2355bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2356bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2357bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2358bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2359bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2360bd49e16eSAndy Lutomirski buffer. 23613dc33bd3SKees Cook 23623dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 23633dc33bd3SKees Cook bool "None" 23643dc33bd3SKees Cook help 23653dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 23663dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23673dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23683dc33bd3SKees Cook will be reported to dmesg, so that either old or 23693dc33bd3SKees Cook malicious userspace programs can be identified. 23703dc33bd3SKees Cook 23713dc33bd3SKees Cookendchoice 23723dc33bd3SKees Cook 2373516cbf37STim Birdconfig CMDLINE_BOOL 2374516cbf37STim Bird bool "Built-in kernel command line" 2375a7f7f624SMasahiro Yamada help 2376516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2377516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2378516cbf37STim Bird necessary or convenient to provide some or all of the 2379516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2380516cbf37STim Bird to not rely on the boot loader to provide them.) 2381516cbf37STim Bird 2382516cbf37STim Bird To compile command line arguments into the kernel, 2383516cbf37STim Bird set this option to 'Y', then fill in the 238469711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2385516cbf37STim Bird 2386516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2387516cbf37STim Bird should leave this option set to 'N'. 2388516cbf37STim Bird 2389516cbf37STim Birdconfig CMDLINE 2390516cbf37STim Bird string "Built-in kernel command string" 2391516cbf37STim Bird depends on CMDLINE_BOOL 2392516cbf37STim Bird default "" 2393a7f7f624SMasahiro Yamada help 2394516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2395516cbf37STim Bird image and used at boot time. If the boot loader provides a 2396516cbf37STim Bird command line at boot time, it is appended to this string to 2397516cbf37STim Bird form the full kernel command line, when the system boots. 2398516cbf37STim Bird 2399516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2400516cbf37STim Bird change this behavior. 2401516cbf37STim Bird 2402516cbf37STim Bird In most cases, the command line (whether built-in or provided 2403516cbf37STim Bird by the boot loader) should specify the device for the root 2404516cbf37STim Bird file system. 2405516cbf37STim Bird 2406516cbf37STim Birdconfig CMDLINE_OVERRIDE 2407516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2408645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2409a7f7f624SMasahiro Yamada help 2410516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2411516cbf37STim Bird command line, and use ONLY the built-in command line. 2412516cbf37STim Bird 2413516cbf37STim Bird This is used to work around broken boot loaders. This should 2414516cbf37STim Bird be set to 'N' under normal conditions. 2415516cbf37STim Bird 2416a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2417a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2418a5b9e5a2SAndy Lutomirski default y 2419a7f7f624SMasahiro Yamada help 2420a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2421a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2422a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2423a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2424a5b9e5a2SAndy Lutomirski threading libraries. 2425a5b9e5a2SAndy Lutomirski 2426a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2427a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2428a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2429a5b9e5a2SAndy Lutomirski 2430a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2431a5b9e5a2SAndy Lutomirski 24323aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE 24333aac3ebeSThomas Gleixner bool "Enforce strict size checking for sigaltstack" 24343aac3ebeSThomas Gleixner depends on DYNAMIC_SIGFRAME 24353aac3ebeSThomas Gleixner help 24363aac3ebeSThomas Gleixner For historical reasons MINSIGSTKSZ is a constant which became 24373aac3ebeSThomas Gleixner already too small with AVX512 support. Add a mechanism to 24383aac3ebeSThomas Gleixner enforce strict checking of the sigaltstack size against the 24393aac3ebeSThomas Gleixner real size of the FPU frame. This option enables the check 24403aac3ebeSThomas Gleixner by default. It can also be controlled via the kernel command 24413aac3ebeSThomas Gleixner line option 'strict_sas_size' independent of this config 24423aac3ebeSThomas Gleixner switch. Enabling it might break existing applications which 24433aac3ebeSThomas Gleixner allocate a too small sigaltstack but 'work' because they 24443aac3ebeSThomas Gleixner never get a signal delivered. 24453aac3ebeSThomas Gleixner 24463aac3ebeSThomas Gleixner Say 'N' unless you want to really enforce this check. 24473aac3ebeSThomas Gleixner 2448b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2449b700e7f0SSeth Jennings 2450506f1d07SSam Ravnborgendmenu 2451506f1d07SSam Ravnborg 2452f43b9876SPeter Zijlstraconfig CC_HAS_SLS 2453f43b9876SPeter Zijlstra def_bool $(cc-option,-mharden-sls=all) 2454f43b9876SPeter Zijlstra 2455f43b9876SPeter Zijlstraconfig CC_HAS_RETURN_THUNK 2456f43b9876SPeter Zijlstra def_bool $(cc-option,-mfunction-return=thunk-extern) 2457f43b9876SPeter Zijlstra 2458bea75b33SThomas Gleixnerconfig CC_HAS_ENTRY_PADDING 2459bea75b33SThomas Gleixner def_bool $(cc-option,-fpatchable-function-entry=16,16) 2460bea75b33SThomas Gleixner 2461bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_CFI 2462bea75b33SThomas Gleixner int 2463bea75b33SThomas Gleixner default 59 if FUNCTION_ALIGNMENT_64B 2464bea75b33SThomas Gleixner default 27 if FUNCTION_ALIGNMENT_32B 2465bea75b33SThomas Gleixner default 11 if FUNCTION_ALIGNMENT_16B 2466bea75b33SThomas Gleixner default 3 if FUNCTION_ALIGNMENT_8B 2467bea75b33SThomas Gleixner default 0 2468bea75b33SThomas Gleixner 2469bea75b33SThomas Gleixner# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG 2470bea75b33SThomas Gleixner# except Kconfig can't do arithmetic :/ 2471bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_BYTES 2472bea75b33SThomas Gleixner int 2473bea75b33SThomas Gleixner default FUNCTION_PADDING_CFI if CFI_CLANG 2474bea75b33SThomas Gleixner default FUNCTION_ALIGNMENT 2475bea75b33SThomas Gleixner 2476931ab636SPeter Zijlstraconfig CALL_PADDING 2477931ab636SPeter Zijlstra def_bool n 2478931ab636SPeter Zijlstra depends on CC_HAS_ENTRY_PADDING && OBJTOOL 2479931ab636SPeter Zijlstra select FUNCTION_ALIGNMENT_16B 2480931ab636SPeter Zijlstra 2481931ab636SPeter Zijlstraconfig FINEIBT 2482931ab636SPeter Zijlstra def_bool y 2483931ab636SPeter Zijlstra depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE 2484931ab636SPeter Zijlstra select CALL_PADDING 2485931ab636SPeter Zijlstra 24868f7c0d8bSThomas Gleixnerconfig HAVE_CALL_THUNKS 24878f7c0d8bSThomas Gleixner def_bool y 2488bea75b33SThomas Gleixner depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL 24898f7c0d8bSThomas Gleixner 24908f7c0d8bSThomas Gleixnerconfig CALL_THUNKS 24918f7c0d8bSThomas Gleixner def_bool n 2492931ab636SPeter Zijlstra select CALL_PADDING 24938f7c0d8bSThomas Gleixner 2494b341b20dSPeter Zijlstraconfig PREFIX_SYMBOLS 2495b341b20dSPeter Zijlstra def_bool y 2496931ab636SPeter Zijlstra depends on CALL_PADDING && !CFI_CLANG 2497b341b20dSPeter Zijlstra 2498f43b9876SPeter Zijlstramenuconfig SPECULATION_MITIGATIONS 2499f43b9876SPeter Zijlstra bool "Mitigations for speculative execution vulnerabilities" 2500f43b9876SPeter Zijlstra default y 2501f43b9876SPeter Zijlstra help 2502f43b9876SPeter Zijlstra Say Y here to enable options which enable mitigations for 2503f43b9876SPeter Zijlstra speculative execution hardware vulnerabilities. 2504f43b9876SPeter Zijlstra 2505f43b9876SPeter Zijlstra If you say N, all mitigations will be disabled. You really 2506f43b9876SPeter Zijlstra should know what you are doing to say so. 2507f43b9876SPeter Zijlstra 2508f43b9876SPeter Zijlstraif SPECULATION_MITIGATIONS 2509f43b9876SPeter Zijlstra 2510f43b9876SPeter Zijlstraconfig PAGE_TABLE_ISOLATION 2511f43b9876SPeter Zijlstra bool "Remove the kernel mapping in user mode" 2512f43b9876SPeter Zijlstra default y 2513f43b9876SPeter Zijlstra depends on (X86_64 || X86_PAE) 2514f43b9876SPeter Zijlstra help 2515f43b9876SPeter Zijlstra This feature reduces the number of hardware side channels by 2516f43b9876SPeter Zijlstra ensuring that the majority of kernel addresses are not mapped 2517f43b9876SPeter Zijlstra into userspace. 2518f43b9876SPeter Zijlstra 2519ff61f079SJonathan Corbet See Documentation/arch/x86/pti.rst for more details. 2520f43b9876SPeter Zijlstra 2521f43b9876SPeter Zijlstraconfig RETPOLINE 2522f43b9876SPeter Zijlstra bool "Avoid speculative indirect branches in kernel" 2523f43b9876SPeter Zijlstra select OBJTOOL if HAVE_OBJTOOL 2524f43b9876SPeter Zijlstra default y 2525f43b9876SPeter Zijlstra help 2526f43b9876SPeter Zijlstra Compile kernel with the retpoline compiler options to guard against 2527f43b9876SPeter Zijlstra kernel-to-user data leaks by avoiding speculative indirect 2528f43b9876SPeter Zijlstra branches. Requires a compiler with -mindirect-branch=thunk-extern 2529f43b9876SPeter Zijlstra support for full protection. The kernel may run slower. 2530f43b9876SPeter Zijlstra 2531f43b9876SPeter Zijlstraconfig RETHUNK 2532f43b9876SPeter Zijlstra bool "Enable return-thunks" 2533f43b9876SPeter Zijlstra depends on RETPOLINE && CC_HAS_RETURN_THUNK 2534f43b9876SPeter Zijlstra select OBJTOOL if HAVE_OBJTOOL 2535b648ab48SBen Hutchings default y if X86_64 2536f43b9876SPeter Zijlstra help 2537f43b9876SPeter Zijlstra Compile the kernel with the return-thunks compiler option to guard 2538f43b9876SPeter Zijlstra against kernel-to-user data leaks by avoiding return speculation. 2539f43b9876SPeter Zijlstra Requires a compiler with -mfunction-return=thunk-extern 2540f43b9876SPeter Zijlstra support for full protection. The kernel may run slower. 2541f43b9876SPeter Zijlstra 2542f43b9876SPeter Zijlstraconfig CPU_UNRET_ENTRY 2543f43b9876SPeter Zijlstra bool "Enable UNRET on kernel entry" 2544b648ab48SBen Hutchings depends on CPU_SUP_AMD && RETHUNK && X86_64 2545f43b9876SPeter Zijlstra default y 2546f43b9876SPeter Zijlstra help 2547f43b9876SPeter Zijlstra Compile the kernel with support for the retbleed=unret mitigation. 2548f43b9876SPeter Zijlstra 254980e4c1cdSThomas Gleixnerconfig CALL_DEPTH_TRACKING 255080e4c1cdSThomas Gleixner bool "Mitigate RSB underflow with call depth tracking" 255180e4c1cdSThomas Gleixner depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS 255280e4c1cdSThomas Gleixner select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 255380e4c1cdSThomas Gleixner select CALL_THUNKS 255480e4c1cdSThomas Gleixner default y 255580e4c1cdSThomas Gleixner help 255680e4c1cdSThomas Gleixner Compile the kernel with call depth tracking to mitigate the Intel 255780e4c1cdSThomas Gleixner SKL Return-Speculation-Buffer (RSB) underflow issue. The 255880e4c1cdSThomas Gleixner mitigation is off by default and needs to be enabled on the 255980e4c1cdSThomas Gleixner kernel command line via the retbleed=stuff option. For 256080e4c1cdSThomas Gleixner non-affected systems the overhead of this option is marginal as 256180e4c1cdSThomas Gleixner the call depth tracking is using run-time generated call thunks 256280e4c1cdSThomas Gleixner in a compiler generated padding area and call patching. This 256380e4c1cdSThomas Gleixner increases text size by ~5%. For non affected systems this space 256480e4c1cdSThomas Gleixner is unused. On affected SKL systems this results in a significant 256580e4c1cdSThomas Gleixner performance gain over the IBRS mitigation. 256680e4c1cdSThomas Gleixner 2567e81dc127SThomas Gleixnerconfig CALL_THUNKS_DEBUG 2568e81dc127SThomas Gleixner bool "Enable call thunks and call depth tracking debugging" 2569e81dc127SThomas Gleixner depends on CALL_DEPTH_TRACKING 2570e81dc127SThomas Gleixner select FUNCTION_ALIGNMENT_32B 2571e81dc127SThomas Gleixner default n 2572e81dc127SThomas Gleixner help 2573e81dc127SThomas Gleixner Enable call/ret counters for imbalance detection and build in 2574e81dc127SThomas Gleixner a noisy dmesg about callthunks generation and call patching for 2575e81dc127SThomas Gleixner trouble shooting. The debug prints need to be enabled on the 2576e81dc127SThomas Gleixner kernel command line with 'debug-callthunks'. 257754628de6SRandy Dunlap Only enable this when you are debugging call thunks as this 257854628de6SRandy Dunlap creates a noticeable runtime overhead. If unsure say N. 257980e4c1cdSThomas Gleixner 2580f43b9876SPeter Zijlstraconfig CPU_IBPB_ENTRY 2581f43b9876SPeter Zijlstra bool "Enable IBPB on kernel entry" 2582b648ab48SBen Hutchings depends on CPU_SUP_AMD && X86_64 2583f43b9876SPeter Zijlstra default y 2584f43b9876SPeter Zijlstra help 2585f43b9876SPeter Zijlstra Compile the kernel with support for the retbleed=ibpb mitigation. 2586f43b9876SPeter Zijlstra 2587f43b9876SPeter Zijlstraconfig CPU_IBRS_ENTRY 2588f43b9876SPeter Zijlstra bool "Enable IBRS on kernel entry" 2589b648ab48SBen Hutchings depends on CPU_SUP_INTEL && X86_64 2590f43b9876SPeter Zijlstra default y 2591f43b9876SPeter Zijlstra help 2592f43b9876SPeter Zijlstra Compile the kernel with support for the spectre_v2=ibrs mitigation. 2593f43b9876SPeter Zijlstra This mitigates both spectre_v2 and retbleed at great cost to 2594f43b9876SPeter Zijlstra performance. 2595f43b9876SPeter Zijlstra 2596*fb3bd914SBorislav Petkov (AMD)config CPU_SRSO 2597*fb3bd914SBorislav Petkov (AMD) bool "Mitigate speculative RAS overflow on AMD" 2598*fb3bd914SBorislav Petkov (AMD) depends on CPU_SUP_AMD && X86_64 && RETHUNK 2599*fb3bd914SBorislav Petkov (AMD) default y 2600*fb3bd914SBorislav Petkov (AMD) help 2601*fb3bd914SBorislav Petkov (AMD) Enable the SRSO mitigation needed on AMD Zen1-4 machines. 2602*fb3bd914SBorislav Petkov (AMD) 2603f43b9876SPeter Zijlstraconfig SLS 2604f43b9876SPeter Zijlstra bool "Mitigate Straight-Line-Speculation" 2605f43b9876SPeter Zijlstra depends on CC_HAS_SLS && X86_64 2606f43b9876SPeter Zijlstra select OBJTOOL if HAVE_OBJTOOL 2607f43b9876SPeter Zijlstra default n 2608f43b9876SPeter Zijlstra help 2609f43b9876SPeter Zijlstra Compile the kernel with straight-line-speculation options to guard 2610f43b9876SPeter Zijlstra against straight line speculation. The kernel image might be slightly 2611f43b9876SPeter Zijlstra larger. 2612f43b9876SPeter Zijlstra 2613f43b9876SPeter Zijlstraendif 2614f43b9876SPeter Zijlstra 26153072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 26163072e413SMichal Hocko def_bool y 26175c11f00bSDavid Hildenbrand depends on ARCH_ENABLE_MEMORY_HOTPLUG 26183072e413SMichal Hocko 2619f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 2620f91ef222SOscar Salvador def_bool y 2621f91ef222SOscar Salvador 2622da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2623e279b6c1SSam Ravnborg 2624e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 26253c2362e6SHarvey Harrison def_bool y 262644556530SZhimin Gu depends on HIBERNATION 2627e279b6c1SSam Ravnborg 2628e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2629e279b6c1SSam Ravnborg 2630e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2631e279b6c1SSam Ravnborg 2632a6b68076SAndi Kleenconfig X86_APM_BOOT 26336fc108a0SJan Beulich def_bool y 2634282e5aabSPaul Bolle depends on APM 2635a6b68076SAndi Kleen 2636e279b6c1SSam Ravnborgmenuconfig APM 2637e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2638efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2639a7f7f624SMasahiro Yamada help 2640e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2641e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2642e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2643e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2644e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2645e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2646e279b6c1SSam Ravnborg 2647e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2648e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2649e279b6c1SSam Ravnborg 2650e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2651e279b6c1SSam Ravnborg machines with more than one CPU. 2652e279b6c1SSam Ravnborg 2653e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2654151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 26552dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2656e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2657e279b6c1SSam Ravnborg 2658e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2659e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2660e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2661e279b6c1SSam Ravnborg 2662e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2663e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2664e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2665e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2666e279b6c1SSam Ravnborg 2667e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2668e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2669e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2670e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2671e279b6c1SSam Ravnborg APM in your BIOS). 2672e279b6c1SSam Ravnborg 2673e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2674e279b6c1SSam Ravnborg "weird" problems: 2675e279b6c1SSam Ravnborg 2676e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2677e279b6c1SSam Ravnborg enabled. 26787987448fSStephen Kitt 2) pass the "idle=poll" option to the kernel 2679e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2680e279b6c1SSam Ravnborg the "no387" option to the kernel 2681e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2682e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2683e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2684e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2685e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2686e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2687e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2688e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2689e279b6c1SSam Ravnborg 11) exchange RAM chips 2690e279b6c1SSam Ravnborg 12) exchange the motherboard. 2691e279b6c1SSam Ravnborg 2692e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2693e279b6c1SSam Ravnborg module will be called apm. 2694e279b6c1SSam Ravnborg 2695e279b6c1SSam Ravnborgif APM 2696e279b6c1SSam Ravnborg 2697e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2698e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2699a7f7f624SMasahiro Yamada help 2700e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2701e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2702e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2703e279b6c1SSam Ravnborg 2704e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2705e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2706a7f7f624SMasahiro Yamada help 2707e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2708e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2709e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2710e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2711e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2712e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2713e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2714e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2715e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2716e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2717e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2718e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2719e279b6c1SSam Ravnborg this feature. 2720e279b6c1SSam Ravnborg 2721e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2722dd8af076SLen Brown depends on CPU_IDLE 2723e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2724a7f7f624SMasahiro Yamada help 2725e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2726e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2727e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2728e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2729e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2730e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2731e279b6c1SSam Ravnborg this option does nothing.) 2732e279b6c1SSam Ravnborg 2733e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2734e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2735a7f7f624SMasahiro Yamada help 2736e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2737e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2738e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2739e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2740e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2741e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2742e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2743e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2744e279b6c1SSam Ravnborg especially if you are using gpm. 2745e279b6c1SSam Ravnborg 2746e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2747e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2748a7f7f624SMasahiro Yamada help 2749e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2750e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2751e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2752e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2753e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2754e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2755e279b6c1SSam Ravnborg 2756e279b6c1SSam Ravnborgendif # APM 2757e279b6c1SSam Ravnborg 2758bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2759e279b6c1SSam Ravnborg 2760e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2761e279b6c1SSam Ravnborg 276227471fdbSAndy Henroidsource "drivers/idle/Kconfig" 276327471fdbSAndy Henroid 2764e279b6c1SSam Ravnborgendmenu 2765e279b6c1SSam Ravnborg 2766e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2767e279b6c1SSam Ravnborg 2768e279b6c1SSam Ravnborgchoice 2769e279b6c1SSam Ravnborg prompt "PCI access mode" 2770efefa6f6SIngo Molnar depends on X86_32 && PCI 2771e279b6c1SSam Ravnborg default PCI_GOANY 2772a7f7f624SMasahiro Yamada help 2773e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2774e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2775e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2776e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2777e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2778e279b6c1SSam Ravnborg 2779e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2780e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2781e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2782e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2783e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2784e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2785e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2786e279b6c1SSam Ravnborg 2787e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2788e279b6c1SSam Ravnborg bool "BIOS" 2789e279b6c1SSam Ravnborg 2790e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2791e279b6c1SSam Ravnborg bool "MMConfig" 2792e279b6c1SSam Ravnborg 2793e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2794e279b6c1SSam Ravnborg bool "Direct" 2795e279b6c1SSam Ravnborg 27963ef0e1f8SAndres Salomonconfig PCI_GOOLPC 279776fb6570SDaniel Drake bool "OLPC XO-1" 27983ef0e1f8SAndres Salomon depends on OLPC 27993ef0e1f8SAndres Salomon 28002bdd1b03SAndres Salomonconfig PCI_GOANY 28012bdd1b03SAndres Salomon bool "Any" 28022bdd1b03SAndres Salomon 2803e279b6c1SSam Ravnborgendchoice 2804e279b6c1SSam Ravnborg 2805e279b6c1SSam Ravnborgconfig PCI_BIOS 28063c2362e6SHarvey Harrison def_bool y 2807efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2808e279b6c1SSam Ravnborg 2809e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2810e279b6c1SSam Ravnborgconfig PCI_DIRECT 28113c2362e6SHarvey Harrison def_bool y 28120aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2813e279b6c1SSam Ravnborg 2814e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2815b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2816b45c9f36SJan Kiszka default y 28174590d98fSAndy Shevchenko depends on PCI && (ACPI || JAILHOUSE_GUEST) 2818b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2819e279b6c1SSam Ravnborg 28203ef0e1f8SAndres Salomonconfig PCI_OLPC 28212bdd1b03SAndres Salomon def_bool y 28222bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 28233ef0e1f8SAndres Salomon 2824b5401a96SAlex Nixonconfig PCI_XEN 2825b5401a96SAlex Nixon def_bool y 2826b5401a96SAlex Nixon depends on PCI && XEN 2827b5401a96SAlex Nixon 28288364e1f8SJan Kiszkaconfig MMCONF_FAM10H 28298364e1f8SJan Kiszka def_bool y 28308364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2831e279b6c1SSam Ravnborg 28323f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 28336a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 28346ea30386SKees Cook depends on PCI 28353f6ea84aSIra W. Snyder help 28363f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 28373f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 28383f6ea84aSIra W. Snyder not have ACPI. 28393f6ea84aSIra W. Snyder 284064a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 284164a5fed6SBjorn Helgaas is known to be incomplete. 284264a5fed6SBjorn Helgaas 284364a5fed6SBjorn Helgaas You should say N unless you know you need this. 284464a5fed6SBjorn Helgaas 28453a495511SWilliam Breathitt Grayconfig ISA_BUS 284617a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 28473a495511SWilliam Breathitt Gray help 284817a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 284917a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 285017a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 285117a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 285217a2a129SWilliam Breathitt Gray not have an ISA bus. 28533a495511SWilliam Breathitt Gray 28543a495511SWilliam Breathitt Gray If unsure, say N. 28553a495511SWilliam Breathitt Gray 28561c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2857e279b6c1SSam Ravnborgconfig ISA_DMA_API 28581c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 28591c00f016SDavid Rientjes default y 28601c00f016SDavid Rientjes help 28611c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 28621c00f016SDavid Rientjes If unsure, say Y. 2863e279b6c1SSam Ravnborg 286451e68d05SLinus Torvaldsif X86_32 286551e68d05SLinus Torvalds 2866e279b6c1SSam Ravnborgconfig ISA 2867e279b6c1SSam Ravnborg bool "ISA support" 2868a7f7f624SMasahiro Yamada help 2869e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2870e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2871e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2872e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2873e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2874e279b6c1SSam Ravnborg 2875e279b6c1SSam Ravnborgconfig SCx200 2876e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2877a7f7f624SMasahiro Yamada help 2878e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2879e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2880e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2881e279b6c1SSam Ravnborg for other scx200_* drivers. 2882e279b6c1SSam Ravnborg 2883e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2884e279b6c1SSam Ravnborg 2885e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2886e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2887592913ecSJohn Stultz depends on SCx200 2888e279b6c1SSam Ravnborg default y 2889a7f7f624SMasahiro Yamada help 2890e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2891e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2892e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2893e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2894e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2895e279b6c1SSam Ravnborg 28963ef0e1f8SAndres Salomonconfig OLPC 28973ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 289854008979SThomas Gleixner depends on !X86_PAE 28993c554946SAndres Salomon select GPIOLIB 2900dc3119e7SThomas Gleixner select OF 290145bb1674SDaniel Drake select OF_PROMTREE 2902b4e51854SGrant Likely select IRQ_DOMAIN 29030c3d931bSLubomir Rintel select OLPC_EC 2904a7f7f624SMasahiro Yamada help 29053ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 29063ef0e1f8SAndres Salomon XO hardware. 29073ef0e1f8SAndres Salomon 2908a3128588SDaniel Drakeconfig OLPC_XO1_PM 2909a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 2910fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 2911a7f7f624SMasahiro Yamada help 291297c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2913bf1ebf00SDaniel Drake 2914cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2915cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2916cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2917a7f7f624SMasahiro Yamada help 2918cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2919cfee9597SDaniel Drake programmable wakeup source. 2920cfee9597SDaniel Drake 29217feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 29227feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 292392e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2924ed8e47feSRandy Dunlap depends on INPUT=y 2925d8d01a63SDaniel Drake select POWER_SUPPLY 2926a7f7f624SMasahiro Yamada help 29277feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 29287bc74b3dSDaniel Drake - EC-driven system wakeups 29297feda8e9SDaniel Drake - Power button 29307bc74b3dSDaniel Drake - Ebook switch 29312cf2baeaSDaniel Drake - Lid switch 2932e1040ac6SDaniel Drake - AC adapter status updates 2933e1040ac6SDaniel Drake - Battery status updates 29347feda8e9SDaniel Drake 2935a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2936a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2937d8d01a63SDaniel Drake depends on OLPC && ACPI 2938d8d01a63SDaniel Drake select POWER_SUPPLY 2939a7f7f624SMasahiro Yamada help 2940a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2941a0f30f59SDaniel Drake - EC-driven system wakeups 2942a0f30f59SDaniel Drake - AC adapter status updates 2943a0f30f59SDaniel Drake - Battery status updates 2944e279b6c1SSam Ravnborg 2945d4f3e350SEd Wildgooseconfig ALIX 2946d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2947d4f3e350SEd Wildgoose select GPIOLIB 2948a7f7f624SMasahiro Yamada help 2949d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2950d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2951d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2952d4f3e350SEd Wildgoose get added here. 2953d4f3e350SEd Wildgoose 2954d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2955d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2956d4f3e350SEd Wildgoose 2957d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2958d4f3e350SEd Wildgoose 2959da4e3302SPhilip Prindevilleconfig NET5501 2960da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2961da4e3302SPhilip Prindeville select GPIOLIB 2962a7f7f624SMasahiro Yamada help 2963da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2964da4e3302SPhilip Prindeville 29653197059aSPhilip A. Prindevilleconfig GEOS 29663197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 29673197059aSPhilip A. Prindeville select GPIOLIB 29683197059aSPhilip A. Prindeville depends on DMI 2969a7f7f624SMasahiro Yamada help 29703197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 29713197059aSPhilip A. Prindeville 29727d029125SVivien Didelotconfig TS5500 29737d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 29747d029125SVivien Didelot depends on MELAN 29757d029125SVivien Didelot select CHECK_SIGNATURE 29767d029125SVivien Didelot select NEW_LEDS 29777d029125SVivien Didelot select LEDS_CLASS 2978a7f7f624SMasahiro Yamada help 29797d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 29807d029125SVivien Didelot 2981e279b6c1SSam Ravnborgendif # X86_32 2982e279b6c1SSam Ravnborg 298323ac4ae8SAndreas Herrmannconfig AMD_NB 2984e279b6c1SSam Ravnborg def_bool y 29850e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2986e279b6c1SSam Ravnborg 2987e279b6c1SSam Ravnborgendmenu 2988e279b6c1SSam Ravnborg 29891572497cSChristoph Hellwigmenu "Binary Emulations" 2990e279b6c1SSam Ravnborg 2991e279b6c1SSam Ravnborgconfig IA32_EMULATION 2992e279b6c1SSam Ravnborg bool "IA32 Emulation" 2993e279b6c1SSam Ravnborg depends on X86_64 299439f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2995d1603990SRandy Dunlap select BINFMT_ELF 299639f88911SIngo Molnar select COMPAT_OLD_SIGACTION 2997a7f7f624SMasahiro Yamada help 29985fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 29995fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 30005fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 3001e279b6c1SSam Ravnborg 300283a44a4fSMasahiro Yamadaconfig X86_X32_ABI 30036ea30386SKees Cook bool "x32 ABI for 64-bit mode" 30049b54050bSBrian Gerst depends on X86_64 3005aaeed6ecSNathan Chancellor # llvm-objcopy does not convert x86_64 .note.gnu.property or 3006aaeed6ecSNathan Chancellor # compressed debug sections to x86_x32 properly: 3007aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/514 3008aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/1141 3009aaeed6ecSNathan Chancellor depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) 3010a7f7f624SMasahiro Yamada help 30115fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 30125fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 30135fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 30145fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 30155fd92e65SH. J. Lu 3016953fee1dSIngo Molnarconfig COMPAT_32 3017953fee1dSIngo Molnar def_bool y 3018953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 3019953fee1dSIngo Molnar select HAVE_UID16 3020953fee1dSIngo Molnar select OLD_SIGSUSPEND3 3021953fee1dSIngo Molnar 3022e279b6c1SSam Ravnborgconfig COMPAT 30233c2362e6SHarvey Harrison def_bool y 302483a44a4fSMasahiro Yamada depends on IA32_EMULATION || X86_X32_ABI 3025e279b6c1SSam Ravnborg 3026e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 30273120e25eSJan Beulich def_bool y 3028a9251280SLinus Torvalds depends on COMPAT 3029ee009e4aSDavid Howells 3030e279b6c1SSam Ravnborgendmenu 3031e279b6c1SSam Ravnborg 3032e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 3033e5beae16SKeith Packard def_bool y 3034e5beae16SKeith Packard depends on X86_32 3035e5beae16SKeith Packard 3036edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 30375e8ebd84SJason A. Donenfeld 30385e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 3039