1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0 2daa93fabSSam Ravnborg# Select 32 or 64 bit 3daa93fabSSam Ravnborgconfig 64BIT 4104daea1SMasahiro Yamada bool "64-bit kernel" if "$(ARCH)" = "x86" 5104daea1SMasahiro Yamada default "$(ARCH)" != "i386" 6a7f7f624SMasahiro Yamada help 7daa93fabSSam Ravnborg Say yes to build a 64-bit kernel - formerly known as x86_64 8daa93fabSSam Ravnborg Say no to build a 32-bit kernel - formerly known as i386 9daa93fabSSam Ravnborg 10daa93fabSSam Ravnborgconfig X86_32 113120e25eSJan Beulich def_bool y 123120e25eSJan Beulich depends on !64BIT 13341c787eSIngo Molnar # Options that are inherently 32-bit kernel only: 14341c787eSIngo Molnar select ARCH_WANT_IPC_PARSE_VERSION 15341c787eSIngo Molnar select CLKSRC_I8253 16341c787eSIngo Molnar select CLONE_BACKWARDS 17157e118bSThomas Gleixner select GENERIC_VDSO_32 18117ed454SThomas Gleixner select HAVE_DEBUG_STACKOVERFLOW 19157e118bSThomas Gleixner select KMAP_LOCAL 20341c787eSIngo Molnar select MODULES_USE_ELF_REL 21341c787eSIngo Molnar select OLD_SIGACTION 222ca408d9SBrian Gerst select ARCH_SPLIT_ARG64 23daa93fabSSam Ravnborg 24daa93fabSSam Ravnborgconfig X86_64 253120e25eSJan Beulich def_bool y 263120e25eSJan Beulich depends on 64BIT 27d94e0685SIngo Molnar # Options that are inherently 64-bit kernel only: 284eb0716eSAlexandre Ghiti select ARCH_HAS_GIGANTIC_PAGE 29c12d3362SArd Biesheuvel select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 300bff0aaeSSuren Baghdasaryan select ARCH_SUPPORTS_PER_VMA_LOCK 31d94e0685SIngo Molnar select HAVE_ARCH_SOFT_DIRTY 32d94e0685SIngo Molnar select MODULES_USE_ELF_RELA 33f616ab59SChristoph Hellwig select NEED_DMA_MAP_STATE 3409230cbcSChristoph Hellwig select SWIOTLB 357facdc42SAl Viro select ARCH_HAS_ELFCORE_COMPAT 3663703f37SKefeng Wang select ZONE_DMA32 371032c0baSSam Ravnborg 38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE 39518049d9SSteven Rostedt (VMware) def_bool y 40518049d9SSteven Rostedt (VMware) depends on X86_32 41518049d9SSteven Rostedt (VMware) depends on FUNCTION_TRACER 42518049d9SSteven Rostedt (VMware) select DYNAMIC_FTRACE 43518049d9SSteven Rostedt (VMware) help 44518049d9SSteven Rostedt (VMware) We keep the static function tracing (!DYNAMIC_FTRACE) around 45518049d9SSteven Rostedt (VMware) in order to test the non static function tracing in the 46518049d9SSteven Rostedt (VMware) generic code, as other architectures still use it. But we 47518049d9SSteven Rostedt (VMware) only need to keep it around for x86_64. No need to keep it 48518049d9SSteven Rostedt (VMware) for x86_32. For x86_32, force DYNAMIC_FTRACE. 49d94e0685SIngo Molnar# 50d94e0685SIngo Molnar# Arch settings 51d94e0685SIngo Molnar# 52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be 53d94e0685SIngo Molnar# ported to 32-bit as well. ) 54d94e0685SIngo Molnar# 558d5fffb9SSam Ravnborgconfig X86 563c2362e6SHarvey Harrison def_bool y 57c763ea26SIngo Molnar # 58c763ea26SIngo Molnar # Note: keep this list sorted alphabetically 59c763ea26SIngo Molnar # 606471b825SIngo Molnar select ACPI_LEGACY_TABLES_LOOKUP if ACPI 616e0a0ea1SGraeme Gregory select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 62a02f66bbSJames Morse select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU 63942fa985SYury Norov select ARCH_32BIT_OFF_T if X86_32 642a21ad57SThomas Gleixner select ARCH_CLOCKSOURCE_INIT 651f6d3a8fSMasami Hiramatsu select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 661e866974SAnshuman Khandual select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION 675c11f00bSDavid Hildenbrand select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 6891024b3cSAnshuman Khandual select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 69cebc774fSAnshuman Khandual select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) 701e866974SAnshuman Khandual select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE 7191dda51aSAleksey Makarov select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 72c2280be8SAnshuman Khandual select ARCH_HAS_CACHE_LINE_SIZE 731156b441SDavidlohr Bueso select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION 747c7077a7SThomas Gleixner select ARCH_HAS_CPU_FINALIZE_INIT 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 10504d5ea46SAneesh Kumar K.V select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 1066471b825SIngo Molnar select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 10777fbbc81SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 1085e2c18c0SMark Salter select ARCH_MIGHT_HAVE_PC_SERIO 1093599fe12SThomas Gleixner select ARCH_STACKWALK 1102c870e61SArnd Bergmann select ARCH_SUPPORTS_ACPI 1116471b825SIngo Molnar select ARCH_SUPPORTS_ATOMIC_RMW 1125d6ad668SMike Rapoport select ARCH_SUPPORTS_DEBUG_PAGEALLOC 113d283d422SPasha Tatashin select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 1146471b825SIngo Molnar select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 11514df3267SThomas Gleixner select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 1163c516f89SSami Tolvanen select ARCH_SUPPORTS_CFI_CLANG if X86_64 1173c516f89SSami Tolvanen select ARCH_USES_CFI_TRAPS if X86_64 && CFI_CLANG 118583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG 119583bfd48SNathan Chancellor select ARCH_SUPPORTS_LTO_CLANG_THIN 1206471b825SIngo Molnar select ARCH_USE_BUILTIN_BSWAP 121a432b7c0SUros Bizjak select ARCH_USE_CMPXCHG_LOCKREF if X86_CMPXCHG64 122dce44566SAnshuman Khandual select ARCH_USE_MEMTEST 1236471b825SIngo Molnar select ARCH_USE_QUEUED_RWLOCKS 1246471b825SIngo Molnar select ARCH_USE_QUEUED_SPINLOCKS 1252ce0d7f9SMark Brown select ARCH_USE_SYM_ANNOTATIONS 126ce4a4e56SAndy Lutomirski select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 12781c22041SDaniel Borkmann select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 128c763ea26SIngo Molnar select ARCH_WANTS_DYNAMIC_TASK_STRUCT 12951c2ee6dSNick Desaulniers select ARCH_WANTS_NO_INSTR 13007431506SAnshuman Khandual select ARCH_WANT_GENERAL_HUGETLB 1313876d4a3SAlexandre Ghiti select ARCH_WANT_HUGE_PMD_SHARE 13259612b24SNathan Chancellor select ARCH_WANT_LD_ORPHAN_WARN 1330b6f1582SAneesh Kumar K.V select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64 1340b6f1582SAneesh Kumar K.V select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64 13538d8b4e6SHuang Ying select ARCH_WANTS_THP_SWAP if X86_64 136b5f06f64SBalbir Singh select ARCH_HAS_PARANOID_L1D_FLUSH 13710916706SShile Zhang select BUILDTIME_TABLE_SORT 1386471b825SIngo Molnar select CLKEVT_I8253 1396471b825SIngo Molnar select CLOCKSOURCE_VALIDATE_LAST_CYCLE 1406471b825SIngo Molnar select CLOCKSOURCE_WATCHDOG 1417cf8f44aSAlexander Potapenko # Word-size accesses may read uninitialized data past the trailing \0 1427cf8f44aSAlexander Potapenko # in strings and cause false KMSAN reports. 1437cf8f44aSAlexander Potapenko select DCACHE_WORD_ACCESS if !KMSAN 1443aac3ebeSThomas Gleixner select DYNAMIC_SIGFRAME 14545471cd9SLinus Torvalds select EDAC_ATOMIC_SCRUB 14645471cd9SLinus Torvalds select EDAC_SUPPORT 1476471b825SIngo Molnar select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 1486471b825SIngo Molnar select GENERIC_CLOCKEVENTS_MIN_ADJUST 1496471b825SIngo Molnar select GENERIC_CMOS_UPDATE 1506471b825SIngo Molnar select GENERIC_CPU_AUTOPROBE 151*5b95f94cSJames Morse select GENERIC_CPU_DEVICES 15261dc0f55SThomas Gleixner select GENERIC_CPU_VULNERABILITIES 1536471b825SIngo Molnar select GENERIC_EARLY_IOREMAP 15427d6b4d1SThomas Gleixner select GENERIC_ENTRY 1556471b825SIngo Molnar select GENERIC_IOMAP 156c7d6c9ddSThomas Gleixner select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 1570fa115daSThomas Gleixner select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 158ad7a929fSThomas Gleixner select GENERIC_IRQ_MIGRATION if SMP 1596471b825SIngo Molnar select GENERIC_IRQ_PROBE 160c201c917SThomas Gleixner select GENERIC_IRQ_RESERVATION_MODE 1616471b825SIngo Molnar select GENERIC_IRQ_SHOW 1626471b825SIngo Molnar select GENERIC_PENDING_IRQ if SMP 1632ae27137SSteven Price select GENERIC_PTDUMP 1646471b825SIngo Molnar select GENERIC_SMP_IDLE_THREAD 1656471b825SIngo Molnar select GENERIC_TIME_VSYSCALL 1667ac87074SVincenzo Frascino select GENERIC_GETTIMEOFDAY 167550a77a7SDmitry Safonov select GENERIC_VDSO_TIME_NS 1686ca297d4SPeter Zijlstra select GUP_GET_PXX_LOW_HIGH if X86_PAE 16917e5888eSHans de Goede select HARDIRQS_SW_RESEND 1707edaeb68SThomas Gleixner select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 171fcbfe812SNiklas Schnelle select HAS_IOPORT 1726471b825SIngo Molnar select HAVE_ACPI_APEI if ACPI 1736471b825SIngo Molnar select HAVE_ACPI_APEI_NMI if ACPI 1746471b825SIngo Molnar select HAVE_ALIGNED_STRUCT_PAGE if SLUB 1756471b825SIngo Molnar select HAVE_ARCH_AUDITSYSCALL 1766471b825SIngo Molnar select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 177eed1fceeSSong Liu select HAVE_ARCH_HUGE_VMALLOC if X86_64 1786471b825SIngo Molnar select HAVE_ARCH_JUMP_LABEL 179b34006c4SArd Biesheuvel select HAVE_ARCH_JUMP_LABEL_RELATIVE 180d17a1d97SAndrey Ryabinin select HAVE_ARCH_KASAN if X86_64 1810609ae01SDaniel Axtens select HAVE_ARCH_KASAN_VMALLOC if X86_64 1821dc0da6eSAlexander Potapenko select HAVE_ARCH_KFENCE 1834ca8cc8dSAlexander Potapenko select HAVE_ARCH_KMSAN if X86_64 1846471b825SIngo Molnar select HAVE_ARCH_KGDB 1859e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 1869e08f57dSDaniel Cashman select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 1871b028f78SDmitry Safonov select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 188271ca788SArd Biesheuvel select HAVE_ARCH_PREL32_RELOCATIONS 1896471b825SIngo Molnar select HAVE_ARCH_SECCOMP_FILTER 190f7d83c1cSKees Cook select HAVE_ARCH_THREAD_STRUCT_WHITELIST 191afaef01cSAlexander Popov select HAVE_ARCH_STACKLEAK 1926471b825SIngo Molnar select HAVE_ARCH_TRACEHOOK 1936471b825SIngo Molnar select HAVE_ARCH_TRANSPARENT_HUGEPAGE 194a00cc7d9SMatthew Wilcox select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 195b64d8d1eSPeter Xu select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 1967677f7fdSAxel Rasmussen select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD 197e37e43a4SAndy Lutomirski select HAVE_ARCH_VMAP_STACK if X86_64 198fe950f60SKees Cook select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 199c763ea26SIngo Molnar select HAVE_ARCH_WITHIN_STACK_FRAMES 2002ff2b7ecSMasahiro Yamada select HAVE_ASM_MODVERSIONS 2016471b825SIngo Molnar select HAVE_CMPXCHG_DOUBLE 2026471b825SIngo Molnar select HAVE_CMPXCHG_LOCAL 20324a9c541SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_USER if X86_64 20424a9c541SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER 2056471b825SIngo Molnar select HAVE_C_RECORDMCOUNT 20603f16cd0SJosh Poimboeuf select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL 207280981d6SSathvika Vasireddy select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT 2084ed308c4SSteven Rostedt (Google) select HAVE_BUILDTIME_MCOUNT_SORT 2096471b825SIngo Molnar select HAVE_DEBUG_KMEMLEAK 2109c5a3621SAkinobu Mita select HAVE_DMA_CONTIGUOUS 211677aa9f7SSteven Rostedt select HAVE_DYNAMIC_FTRACE 21206aeaaeaSMasami Hiramatsu select HAVE_DYNAMIC_FTRACE_WITH_REGS 21302a474caSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 214562955feSSteven Rostedt (VMware) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 215c316eb44SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 216503e4510SHeiko Carstens select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 21703f5781bSWang YanQing select HAVE_EBPF_JIT 21858340a07SJohannes Berg select HAVE_EFFICIENT_UNALIGNED_ACCESS 2196630a8e5SChristoph Hellwig select HAVE_EISA 2205f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 22167a929e0SChristoph Hellwig select HAVE_FAST_GUP 222644e0e8dSSteven Rostedt (VMware) select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 2236471b825SIngo Molnar select HAVE_FTRACE_MCOUNT_RECORD 224d938ba17SDonglin Peng select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 2254a30e4c9SSteven Rostedt (VMware) select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) 2266471b825SIngo Molnar select HAVE_FUNCTION_TRACER 2276b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 2280067f129SK.Prasad select HAVE_HW_BREAKPOINT 2296471b825SIngo Molnar select HAVE_IOREMAP_PROT 230624db9eaSThomas Gleixner select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 2316471b825SIngo Molnar select HAVE_IRQ_TIME_ACCOUNTING 2324ab7674fSJosh Poimboeuf select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL 2336471b825SIngo Molnar select HAVE_KERNEL_BZIP2 2346471b825SIngo Molnar select HAVE_KERNEL_GZIP 2356471b825SIngo Molnar select HAVE_KERNEL_LZ4 2366471b825SIngo Molnar select HAVE_KERNEL_LZMA 2376471b825SIngo Molnar select HAVE_KERNEL_LZO 2386471b825SIngo Molnar select HAVE_KERNEL_XZ 239fb46d057SNick Terrell select HAVE_KERNEL_ZSTD 2406471b825SIngo Molnar select HAVE_KPROBES 2416471b825SIngo Molnar select HAVE_KPROBES_ON_FTRACE 242540adea3SMasami Hiramatsu select HAVE_FUNCTION_ERROR_INJECTION 2436471b825SIngo Molnar select HAVE_KRETPROBES 244f3a112c0SMasami Hiramatsu select HAVE_RETHOOK 2456471b825SIngo Molnar select HAVE_KVM 2466471b825SIngo Molnar select HAVE_LIVEPATCH if X86_64 2470102752eSFrederic Weisbecker select HAVE_MIXED_BREAKPOINTS_REGS 248ee9f8fceSJosh Poimboeuf select HAVE_MOD_ARCH_SPECIFIC 2499f132f7eSJoel Fernandes (Google) select HAVE_MOVE_PMD 250be37c98dSKalesh Singh select HAVE_MOVE_PUD 25122102f45SJosh Poimboeuf select HAVE_NOINSTR_HACK if HAVE_OBJTOOL 25242a0bb3fSPetr Mladek select HAVE_NMI 253489e355bSJosh Poimboeuf select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL 25403f16cd0SJosh Poimboeuf select HAVE_OBJTOOL if X86_64 2556471b825SIngo Molnar select HAVE_OPTPROBES 2566471b825SIngo Molnar select HAVE_PCSPKR_PLATFORM 2576471b825SIngo Molnar select HAVE_PERF_EVENTS 258c01d4323SFrederic Weisbecker select HAVE_PERF_EVENTS_NMI 25992e5aae4SNicholas Piggin select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 260eb01d42aSChristoph Hellwig select HAVE_PCI 261c5e63197SJiri Olsa select HAVE_PERF_REGS 262c5ebcedbSJiri Olsa select HAVE_PERF_USER_STACK_DUMP 263ff2e6d72SPeter Zijlstra select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 2641e9fdf21SPeter Zijlstra select MMU_GATHER_MERGE_VMAS 26500998085SThomas Gleixner select HAVE_POSIX_CPU_TIMERS_TASK_WORK 2666471b825SIngo Molnar select HAVE_REGS_AND_STACK_ACCESS_API 26703f16cd0SJosh Poimboeuf select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION 2683c88ee19SMasami Hiramatsu select HAVE_FUNCTION_ARG_ACCESS_API 2697ecd19cfSKefeng Wang select HAVE_SETUP_PER_CPU_AREA 270cd1a41ceSThomas Gleixner select HAVE_SOFTIRQ_ON_OWN_STACK 271d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 27203f16cd0SJosh Poimboeuf select HAVE_STACK_VALIDATION if HAVE_OBJTOOL 273e6d6c071SJosh Poimboeuf select HAVE_STATIC_CALL 27403f16cd0SJosh Poimboeuf select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL 27599cf983cSMark Rutland select HAVE_PREEMPT_DYNAMIC_CALL 276d6761b8fSMathieu Desnoyers select HAVE_RSEQ 27709498135SMiguel Ojeda select HAVE_RUST if X86_64 2786471b825SIngo Molnar select HAVE_SYSCALL_TRACEPOINTS 2795f3da8c0SJosh Poimboeuf select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL 2806471b825SIngo Molnar select HAVE_UNSTABLE_SCHED_CLOCK 2817c68af6eSAvi Kivity select HAVE_USER_RETURN_NOTIFIER 2827ac87074SVincenzo Frascino select HAVE_GENERIC_VDSO 2830c7ffa32SThomas Gleixner select HOTPLUG_PARALLEL if SMP && X86_64 28405736e4aSThomas Gleixner select HOTPLUG_SMT if SMP 2850c7ffa32SThomas Gleixner select HOTPLUG_SPLIT_STARTUP if SMP && X86_32 286c0185808SThomas Gleixner select IRQ_FORCED_THREADING 287c2508ec5SLinus Torvalds select LOCK_MM_AND_FIND_VMA 2887ecd19cfSKefeng Wang select NEED_PER_CPU_EMBED_FIRST_CHUNK 2897ecd19cfSKefeng Wang select NEED_PER_CPU_PAGE_FIRST_CHUNK 29086596f0aSChristoph Hellwig select NEED_SG_DMA_LENGTH 2912eac9c2dSChristoph Hellwig select PCI_DOMAINS if PCI 292625210cfSSinan Kaya select PCI_LOCKLESS_CONFIG if PCI 2936471b825SIngo Molnar select PERF_EVENTS 2943195ef59SPrarit Bhargava select RTC_LIB 295d6faca40SArnd Bergmann select RTC_MC146818_LIB 2966471b825SIngo Molnar select SPARSE_IRQ 2976471b825SIngo Molnar select SYSCTL_EXCEPTION_TRACE 29815f4eae7SAndy Lutomirski select THREAD_INFO_IN_TASK 2994aae683fSMasahiro Yamada select TRACE_IRQFLAGS_SUPPORT 3004510bffbSMark Rutland select TRACE_IRQFLAGS_NMI_SUPPORT 3016471b825SIngo Molnar select USER_STACKTRACE_SUPPORT 3023b02a051SIngo Molnar select HAVE_ARCH_KCSAN if X86_64 3030c608dadSAubrey Li select PROC_PID_ARCH_STATUS if PROC_FS 30450468e43SJarkko Sakkinen select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX 305d49a0626SPeter Zijlstra select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16 306d49a0626SPeter Zijlstra select FUNCTION_ALIGNMENT_4B 3079e2b4be3SNayna Jain imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 308ceea991aSJiri Olsa select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 3097d8330a5SBalbir Singh 310ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER 3113120e25eSJan Beulich def_bool y 3123120e25eSJan Beulich depends on KPROBES || PERF_EVENTS || UPROBES 313ba7e4d13SIngo Molnar 31451b26adaSLinus Torvaldsconfig OUTPUT_FORMAT 31551b26adaSLinus Torvalds string 31651b26adaSLinus Torvalds default "elf32-i386" if X86_32 31751b26adaSLinus Torvalds default "elf64-x86-64" if X86_64 31851b26adaSLinus Torvalds 3198d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT 3203c2362e6SHarvey Harrison def_bool y 3218d5fffb9SSam Ravnborg 3228d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT 3233c2362e6SHarvey Harrison def_bool y 3248d5fffb9SSam Ravnborg 3258d5fffb9SSam Ravnborgconfig MMU 3263c2362e6SHarvey Harrison def_bool y 3278d5fffb9SSam Ravnborg 3289e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 3299e08f57dSDaniel Cashman default 28 if 64BIT 3309e08f57dSDaniel Cashman default 8 3319e08f57dSDaniel Cashman 3329e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 3339e08f57dSDaniel Cashman default 32 if 64BIT 3349e08f57dSDaniel Cashman default 16 3359e08f57dSDaniel Cashman 3369e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 3379e08f57dSDaniel Cashman default 8 3389e08f57dSDaniel Cashman 3399e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 3409e08f57dSDaniel Cashman default 16 3419e08f57dSDaniel Cashman 3428d5fffb9SSam Ravnborgconfig SBUS 3438d5fffb9SSam Ravnborg bool 3448d5fffb9SSam Ravnborg 3458d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA 3463120e25eSJan Beulich def_bool y 3473120e25eSJan Beulich depends on ISA_DMA_API 3488d5fffb9SSam Ravnborg 349d911c67eSAlexander Potapenkoconfig GENERIC_CSUM 350d911c67eSAlexander Potapenko bool 351d911c67eSAlexander Potapenko default y if KMSAN || KASAN 352d911c67eSAlexander Potapenko 3538d5fffb9SSam Ravnborgconfig GENERIC_BUG 3543c2362e6SHarvey Harrison def_bool y 3558d5fffb9SSam Ravnborg depends on BUG 356b93a531eSJan Beulich select GENERIC_BUG_RELATIVE_POINTERS if X86_64 357b93a531eSJan Beulich 358b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS 359b93a531eSJan Beulich bool 3608d5fffb9SSam Ravnborg 3618d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC 3623120e25eSJan Beulich def_bool y 3633120e25eSJan Beulich depends on ISA_DMA_API 3648d5fffb9SSam Ravnborg 3651032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY 3661032c0baSSam Ravnborg def_bool y 3671032c0baSSam Ravnborg 3689a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX 3699a0b8415Svenkatesh.pallipadi@intel.com def_bool y 3708d5fffb9SSam Ravnborg 371801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE 372801e4062SJohannes Berg def_bool y 373801e4062SJohannes Berg 374f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 375f4cb5700SJohannes Berg def_bool y 376f4cb5700SJohannes Berg 3778d5fffb9SSam Ravnborgconfig AUDIT_ARCH 378e0fd24a3SJan Beulich def_bool y if X86_64 3798d5fffb9SSam Ravnborg 380d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET 381d6f2d75aSAndrey Ryabinin hex 382d6f2d75aSAndrey Ryabinin depends on KASAN 383d6f2d75aSAndrey Ryabinin default 0xdffffc0000000000 384d6f2d75aSAndrey Ryabinin 38569575d38SShane Wangconfig HAVE_INTEL_TXT 38669575d38SShane Wang def_bool y 3876ea30386SKees Cook depends on INTEL_IOMMU && ACPI 38869575d38SShane Wang 3896b0c3d44SSam Ravnborgconfig X86_32_SMP 3906b0c3d44SSam Ravnborg def_bool y 3916b0c3d44SSam Ravnborg depends on X86_32 && SMP 3926b0c3d44SSam Ravnborg 3936b0c3d44SSam Ravnborgconfig X86_64_SMP 3946b0c3d44SSam Ravnborg def_bool y 3956b0c3d44SSam Ravnborg depends on X86_64 && SMP 3966b0c3d44SSam Ravnborg 3972b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES 3982b144498SSrikar Dronamraju def_bool y 3992b144498SSrikar Dronamraju 400d20642f0SRob Herringconfig FIX_EARLYCON_MEM 401d20642f0SRob Herring def_bool y 402d20642f0SRob Herring 40394d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK 40494d49eb3SKirill A. Shutemov bool 40594d49eb3SKirill A. Shutemov 40698233368SKirill A. Shutemovconfig PGTABLE_LEVELS 40798233368SKirill A. Shutemov int 40877ef56e4SKirill A. Shutemov default 5 if X86_5LEVEL 40998233368SKirill A. Shutemov default 4 if X86_64 41098233368SKirill A. Shutemov default 3 if X86_PAE 41198233368SKirill A. Shutemov default 2 41298233368SKirill A. Shutemov 4132a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR 4142a61f474SMasahiro Yamada bool 4151b866781SNathan Chancellor default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT 4161b866781SNathan Chancellor default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) 4172a61f474SMasahiro Yamada help 4182a61f474SMasahiro Yamada We have to make sure stack protector is unconditionally disabled if 4193fb0fdb3SAndy Lutomirski the compiler produces broken code or if it does not let us control 4203fb0fdb3SAndy Lutomirski the segment on 32-bit kernels. 4212a61f474SMasahiro Yamada 422506f1d07SSam Ravnborgmenu "Processor type and features" 423506f1d07SSam Ravnborg 424506f1d07SSam Ravnborgconfig SMP 425506f1d07SSam Ravnborg bool "Symmetric multi-processing support" 426a7f7f624SMasahiro Yamada help 427506f1d07SSam Ravnborg This enables support for systems with more than one CPU. If you have 4284a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 4294a474157SRobert Graffham than one CPU, say Y. 430506f1d07SSam Ravnborg 4314a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 432506f1d07SSam Ravnborg machines, but will use only one CPU of a multiprocessor machine. If 433506f1d07SSam Ravnborg you say Y here, the kernel will run on many, but not all, 4344a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 435506f1d07SSam Ravnborg will run faster if you say N here. 436506f1d07SSam Ravnborg 437506f1d07SSam Ravnborg Note that if you say Y here and choose architecture "586" or 438506f1d07SSam Ravnborg "Pentium" under "Processor family", the kernel will not work on 486 439506f1d07SSam Ravnborg architectures. Similarly, multiprocessor kernels for the "PPro" 440506f1d07SSam Ravnborg architecture may not work on all Pentium based boards. 441506f1d07SSam Ravnborg 442506f1d07SSam Ravnborg People using multiprocessor machines who say Y here should also say 443506f1d07SSam Ravnborg Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 444506f1d07SSam Ravnborg Management" code will be disabled if you say Y here. 445506f1d07SSam Ravnborg 446ff61f079SJonathan Corbet See also <file:Documentation/arch/x86/i386/IO-APIC.rst>, 4474f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 448506f1d07SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 449506f1d07SSam Ravnborg 450506f1d07SSam Ravnborg If you don't know what to do here, say N. 451506f1d07SSam Ravnborg 45206cd9a7dSYinghai Luconfig X86_X2APIC 45306cd9a7dSYinghai Lu bool "Support x2apic" 45419e3d60dSJan Kiszka depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 455a7f7f624SMasahiro Yamada help 45606cd9a7dSYinghai Lu This enables x2apic support on CPUs that have this feature. 45706cd9a7dSYinghai Lu 45806cd9a7dSYinghai Lu This allows 32-bit apic IDs (so it can support very large systems), 45906cd9a7dSYinghai Lu and accesses the local apic via MSRs not via mmio. 46006cd9a7dSYinghai Lu 461b8d1d163SDaniel Sneddon Some Intel systems circa 2022 and later are locked into x2APIC mode 462b8d1d163SDaniel Sneddon and can not fall back to the legacy APIC modes if SGX or TDX are 463e3998434SMateusz Jończyk enabled in the BIOS. They will boot with very reduced functionality 464e3998434SMateusz Jończyk without enabling this option. 465b8d1d163SDaniel Sneddon 46606cd9a7dSYinghai Lu If you don't know what to do here, say N. 46706cd9a7dSYinghai Lu 4686695c85bSYinghai Luconfig X86_MPPARSE 4694590d98fSAndy Shevchenko bool "Enable MPS table" if ACPI 4707a527688SJan Beulich default y 4715ab74722SIngo Molnar depends on X86_LOCAL_APIC 472a7f7f624SMasahiro Yamada help 4736695c85bSYinghai Lu For old smp systems that do not have proper acpi support. Newer systems 4746695c85bSYinghai Lu (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 4756695c85bSYinghai Lu 476ddd70cf9SJun Nakajimaconfig GOLDFISH 477ddd70cf9SJun Nakajima def_bool y 478ddd70cf9SJun Nakajima depends on X86_GOLDFISH 479ddd70cf9SJun Nakajima 480e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL 481e6d42931SJohannes Weiner bool "x86 CPU resource control support" 4826fe07ce3SBabu Moger depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 48359fe5a77SThomas Gleixner select KERNFS 484e79f15a4SChen Yu select PROC_CPU_RESCTRL if PROC_FS 48578e99b4aSFenghua Yu help 486e6d42931SJohannes Weiner Enable x86 CPU resource control support. 4876fe07ce3SBabu Moger 4886fe07ce3SBabu Moger Provide support for the allocation and monitoring of system resources 4896fe07ce3SBabu Moger usage by the CPU. 4906fe07ce3SBabu Moger 4916fe07ce3SBabu Moger Intel calls this Intel Resource Director Technology 4926fe07ce3SBabu Moger (Intel(R) RDT). More information about RDT can be found in the 4936fe07ce3SBabu Moger Intel x86 Architecture Software Developer Manual. 4946fe07ce3SBabu Moger 4956fe07ce3SBabu Moger AMD calls this AMD Platform Quality of Service (AMD QoS). 4966fe07ce3SBabu Moger More information about AMD QoS can be found in the AMD64 Technology 4976fe07ce3SBabu Moger Platform Quality of Service Extensions manual. 49878e99b4aSFenghua Yu 49978e99b4aSFenghua Yu Say N if unsure. 50078e99b4aSFenghua Yu 5018425091fSRavikiran G Thirumalaiif X86_32 502a0d0bb4dSRandy Dunlapconfig X86_BIGSMP 503a0d0bb4dSRandy Dunlap bool "Support for big SMP systems with more than 8 CPUs" 504a0d0bb4dSRandy Dunlap depends on SMP 505a7f7f624SMasahiro Yamada help 506e133f6eaSRandy Dunlap This option is needed for the systems that have more than 8 CPUs. 507a0d0bb4dSRandy Dunlap 508c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 509c5c606d9SRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 510c5c606d9SRavikiran G Thirumalai default y 511a7f7f624SMasahiro Yamada help 51206ac8346SIngo Molnar If you disable this option then the kernel will only support 51306ac8346SIngo Molnar standard PC platforms. (which covers the vast majority of 51406ac8346SIngo Molnar systems out there.) 51506ac8346SIngo Molnar 5168425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5178425091fSRavikiran G Thirumalai for the following (non-PC) 32 bit x86 platforms: 518cb7b8023SBen Hutchings Goldfish (Android emulator) 5198425091fSRavikiran G Thirumalai AMD Elan 5208425091fSRavikiran G Thirumalai RDC R-321x SoC 5218425091fSRavikiran G Thirumalai SGI 320/540 (Visual Workstation) 52283125a3aSAlessandro Rubini STA2X11-based (e.g. Northville) 5233f4110a4SThomas Gleixner Moorestown MID devices 52406ac8346SIngo Molnar 52506ac8346SIngo Molnar If you have one of these systems, or if you want to build a 52606ac8346SIngo Molnar generic distribution kernel, say Y here - otherwise say N. 527758cd94aSJuerg Haefligerendif # X86_32 52806ac8346SIngo Molnar 5298425091fSRavikiran G Thirumalaiif X86_64 5308425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM 5318425091fSRavikiran G Thirumalai bool "Support for extended (non-PC) x86 platforms" 5328425091fSRavikiran G Thirumalai default y 533a7f7f624SMasahiro Yamada help 5348425091fSRavikiran G Thirumalai If you disable this option then the kernel will only support 5358425091fSRavikiran G Thirumalai standard PC platforms. (which covers the vast majority of 5368425091fSRavikiran G Thirumalai systems out there.) 5378425091fSRavikiran G Thirumalai 5388425091fSRavikiran G Thirumalai If you enable this option then you'll be able to select support 5398425091fSRavikiran G Thirumalai for the following (non-PC) 64 bit x86 platforms: 54044b111b5SSteffen Persvold Numascale NumaChip 5418425091fSRavikiran G Thirumalai ScaleMP vSMP 5428425091fSRavikiran G Thirumalai SGI Ultraviolet 5438425091fSRavikiran G Thirumalai 5448425091fSRavikiran G Thirumalai If you have one of these systems, or if you want to build a 5458425091fSRavikiran G Thirumalai generic distribution kernel, say Y here - otherwise say N. 546758cd94aSJuerg Haefligerendif # X86_64 547c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms 548c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 54944b111b5SSteffen Persvoldconfig X86_NUMACHIP 55044b111b5SSteffen Persvold bool "Numascale NumaChip" 55144b111b5SSteffen Persvold depends on X86_64 55244b111b5SSteffen Persvold depends on X86_EXTENDED_PLATFORM 55344b111b5SSteffen Persvold depends on NUMA 55444b111b5SSteffen Persvold depends on SMP 55544b111b5SSteffen Persvold depends on X86_X2APIC 556f9726bfdSDaniel J Blueman depends on PCI_MMCONFIG 557a7f7f624SMasahiro Yamada help 55844b111b5SSteffen Persvold Adds support for Numascale NumaChip large-SMP systems. Needed to 55944b111b5SSteffen Persvold enable more than ~168 cores. 56044b111b5SSteffen Persvold If you don't have one of these, you should say N here. 56103b48632SNick Piggin 5626a48565eSIngo Molnarconfig X86_VSMP 563c5c606d9SRavikiran G Thirumalai bool "ScaleMP vSMP" 5646276a074SBorislav Petkov select HYPERVISOR_GUEST 5656a48565eSIngo Molnar select PARAVIRT 5666a48565eSIngo Molnar depends on X86_64 && PCI 567c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 568ead91d4bSShai Fultheim depends on SMP 569a7f7f624SMasahiro Yamada help 5706a48565eSIngo Molnar Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 5716a48565eSIngo Molnar supposed to run on these EM64T-based machines. Only choose this option 5726a48565eSIngo Molnar if you have one of these machines. 5736a48565eSIngo Molnar 574c5c606d9SRavikiran G Thirumalaiconfig X86_UV 575c5c606d9SRavikiran G Thirumalai bool "SGI Ultraviolet" 576c5c606d9SRavikiran G Thirumalai depends on X86_64 577c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 57854c28d29SJack Steiner depends on NUMA 5791ecb4ae5SAndrew Morton depends on EFI 580c2209ea5SIngo Molnar depends on KEXEC_CORE 5819d6c26e7SSuresh Siddha depends on X86_X2APIC 5821222e564SIngo Molnar depends on PCI 583a7f7f624SMasahiro Yamada help 584c5c606d9SRavikiran G Thirumalai This option is needed in order to support SGI Ultraviolet systems. 585c5c606d9SRavikiran G Thirumalai If you don't have one of these, you should say N here. 586c5c606d9SRavikiran G Thirumalai 587c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms 588c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions 589506f1d07SSam Ravnborg 590ddd70cf9SJun Nakajimaconfig X86_GOLDFISH 591ddd70cf9SJun Nakajima bool "Goldfish (Virtual Platform)" 592cb7b8023SBen Hutchings depends on X86_EXTENDED_PLATFORM 593a7f7f624SMasahiro Yamada help 594ddd70cf9SJun Nakajima Enable support for the Goldfish virtual platform used primarily 595ddd70cf9SJun Nakajima for Android development. Unless you are building for the Android 596ddd70cf9SJun Nakajima Goldfish emulator say N here. 597ddd70cf9SJun Nakajima 598c751e17bSThomas Gleixnerconfig X86_INTEL_CE 599c751e17bSThomas Gleixner bool "CE4100 TV platform" 600c751e17bSThomas Gleixner depends on PCI 601c751e17bSThomas Gleixner depends on PCI_GODIRECT 6026084a6e2SJiang Liu depends on X86_IO_APIC 603c751e17bSThomas Gleixner depends on X86_32 604c751e17bSThomas Gleixner depends on X86_EXTENDED_PLATFORM 60537bc9f50SDirk Brandewie select X86_REBOOTFIXUPS 606da6b737bSSebastian Andrzej Siewior select OF 607da6b737bSSebastian Andrzej Siewior select OF_EARLY_FLATTREE 608a7f7f624SMasahiro Yamada help 609c751e17bSThomas Gleixner Select for the Intel CE media processor (CE4100) SOC. 610c751e17bSThomas Gleixner This option compiles in support for the CE4100 SOC for settop 611c751e17bSThomas Gleixner boxes and media devices. 612c751e17bSThomas Gleixner 6134cb9b00fSDavid Cohenconfig X86_INTEL_MID 61443605ef1SAlan Cox bool "Intel MID platform support" 61543605ef1SAlan Cox depends on X86_EXTENDED_PLATFORM 616edc6bc78SDavid Cohen depends on X86_PLATFORM_DEVICES 6171ea7c673SAlan Cox depends on PCI 6183fda5bb4SAndy Shevchenko depends on X86_64 || (PCI_GOANY && X86_32) 6191ea7c673SAlan Cox depends on X86_IO_APIC 6204cb9b00fSDavid Cohen select I2C 6217c9c3a1eSAlan Cox select DW_APB_TIMER 62254b34aa0SMika Westerberg select INTEL_SCU_PCI 623a7f7f624SMasahiro Yamada help 6244cb9b00fSDavid Cohen Select to build a kernel capable of supporting Intel MID (Mobile 6254cb9b00fSDavid Cohen Internet Device) platform systems which do not have the PCI legacy 6264cb9b00fSDavid Cohen interfaces. If you are building for a PC class system say N here. 6271ea7c673SAlan Cox 6284cb9b00fSDavid Cohen Intel MID platforms are based on an Intel processor and chipset which 6294cb9b00fSDavid Cohen consume less power than most of the x86 derivatives. 63043605ef1SAlan Cox 6318bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK 6328bbc2a13SBryan O'Donoghue bool "Intel Quark platform support" 6338bbc2a13SBryan O'Donoghue depends on X86_32 6348bbc2a13SBryan O'Donoghue depends on X86_EXTENDED_PLATFORM 6358bbc2a13SBryan O'Donoghue depends on X86_PLATFORM_DEVICES 6368bbc2a13SBryan O'Donoghue depends on X86_TSC 6378bbc2a13SBryan O'Donoghue depends on PCI 6388bbc2a13SBryan O'Donoghue depends on PCI_GOANY 6398bbc2a13SBryan O'Donoghue depends on X86_IO_APIC 6408bbc2a13SBryan O'Donoghue select IOSF_MBI 6418bbc2a13SBryan O'Donoghue select INTEL_IMR 6429ab6eb51SAndy Shevchenko select COMMON_CLK 643a7f7f624SMasahiro Yamada help 6448bbc2a13SBryan O'Donoghue Select to include support for Quark X1000 SoC. 6458bbc2a13SBryan O'Donoghue Say Y here if you have a Quark based system such as the Arduino 6468bbc2a13SBryan O'Donoghue compatible Intel Galileo. 6478bbc2a13SBryan O'Donoghue 6483d48aab1SMika Westerbergconfig X86_INTEL_LPSS 6493d48aab1SMika Westerberg bool "Intel Low Power Subsystem Support" 6505962dd22SSinan Kaya depends on X86 && ACPI && PCI 6513d48aab1SMika Westerberg select COMMON_CLK 6520f531431SMathias Nyman select PINCTRL 653eebb3e8dSAndy Shevchenko select IOSF_MBI 654a7f7f624SMasahiro Yamada help 6553d48aab1SMika Westerberg Select to build support for Intel Low Power Subsystem such as 6563d48aab1SMika Westerberg found on Intel Lynxpoint PCH. Selecting this option enables 6570f531431SMathias Nyman things like clock tree (common clock framework) and pincontrol 6580f531431SMathias Nyman which are needed by the LPSS peripheral drivers. 6593d48aab1SMika Westerberg 66092082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE 66192082a88SKen Xue bool "AMD ACPI2Platform devices support" 66292082a88SKen Xue depends on ACPI 66392082a88SKen Xue select COMMON_CLK 66492082a88SKen Xue select PINCTRL 665a7f7f624SMasahiro Yamada help 66692082a88SKen Xue Select to interpret AMD specific ACPI device to platform device 66792082a88SKen Xue such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 66892082a88SKen Xue I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 66992082a88SKen Xue implemented under PINCTRL subsystem. 67092082a88SKen Xue 671ced3ce76SDavid E. Boxconfig IOSF_MBI 672ced3ce76SDavid E. Box tristate "Intel SoC IOSF Sideband support for SoC platforms" 673ced3ce76SDavid E. Box depends on PCI 674a7f7f624SMasahiro Yamada help 675ced3ce76SDavid E. Box This option enables sideband register access support for Intel SoC 676ced3ce76SDavid E. Box platforms. On these platforms the IOSF sideband is used in lieu of 677ced3ce76SDavid E. Box MSR's for some register accesses, mostly but not limited to thermal 678ced3ce76SDavid E. Box and power. Drivers may query the availability of this device to 679ced3ce76SDavid E. Box determine if they need the sideband in order to work on these 680ced3ce76SDavid E. Box platforms. The sideband is available on the following SoC products. 681ced3ce76SDavid E. Box This list is not meant to be exclusive. 682ced3ce76SDavid E. Box - BayTrail 683ced3ce76SDavid E. Box - Braswell 684ced3ce76SDavid E. Box - Quark 685ced3ce76SDavid E. Box 686ced3ce76SDavid E. Box You should say Y if you are running a kernel on one of these SoC's. 687ced3ce76SDavid E. Box 688ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG 689ed2226bdSDavid E. Box bool "Enable IOSF sideband access through debugfs" 690ed2226bdSDavid E. Box depends on IOSF_MBI && DEBUG_FS 691a7f7f624SMasahiro Yamada help 692ed2226bdSDavid E. Box Select this option to expose the IOSF sideband access registers (MCR, 693ed2226bdSDavid E. Box MDR, MCRX) through debugfs to write and read register information from 694ed2226bdSDavid E. Box different units on the SoC. This is most useful for obtaining device 695ed2226bdSDavid E. Box state information for debug and analysis. As this is a general access 696ed2226bdSDavid E. Box mechanism, users of this option would have specific knowledge of the 697ed2226bdSDavid E. Box device they want to access. 698ed2226bdSDavid E. Box 699ed2226bdSDavid E. Box If you don't require the option or are in doubt, say N. 700ed2226bdSDavid E. Box 701c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X 702c5c606d9SRavikiran G Thirumalai bool "RDC R-321x SoC" 703506f1d07SSam Ravnborg depends on X86_32 704c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 705c5c606d9SRavikiran G Thirumalai select M486 706c5c606d9SRavikiran G Thirumalai select X86_REBOOTFIXUPS 707a7f7f624SMasahiro Yamada help 708c5c606d9SRavikiran G Thirumalai This option is needed for RDC R-321x system-on-chip, also known 709c5c606d9SRavikiran G Thirumalai as R-8610-(G). 710c5c606d9SRavikiran G Thirumalai If you don't have one of these chips, you should say N here. 711c5c606d9SRavikiran G Thirumalai 712e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD 7139c398017SIngo Molnar bool "Support non-standard 32-bit SMP architectures" 7149c398017SIngo Molnar depends on X86_32 && SMP 715c5c606d9SRavikiran G Thirumalai depends on X86_EXTENDED_PLATFORM 716a7f7f624SMasahiro Yamada help 717b5660ba7SH. Peter Anvin This option compiles in the bigsmp and STA2X11 default 718b5660ba7SH. Peter Anvin subarchitectures. It is intended for a generic binary 719b5660ba7SH. Peter Anvin kernel. If you select them all, kernel will probe it one by 720b5660ba7SH. Peter Anvin one and will fallback to default. 721d49c4288SYinghai Lu 722c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms 723d49c4288SYinghai Lu 724d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE 7256fc108a0SJan Beulich def_bool y 726d949f36fSLinus Torvalds # MCE code calls memory_failure(): 727d949f36fSLinus Torvalds depends on X86_MCE 728d949f36fSLinus Torvalds # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 729d949f36fSLinus Torvalds # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 730d949f36fSLinus Torvalds depends on X86_64 || !SPARSEMEM 731d949f36fSLinus Torvalds select ARCH_SUPPORTS_MEMORY_FAILURE 732d949f36fSLinus Torvalds 73383125a3aSAlessandro Rubiniconfig STA2X11 73483125a3aSAlessandro Rubini bool "STA2X11 Companion Chip Support" 73583125a3aSAlessandro Rubini depends on X86_32_NON_STANDARD && PCI 73683125a3aSAlessandro Rubini select SWIOTLB 73783125a3aSAlessandro Rubini select MFD_STA2X11 7380145071bSLinus Walleij select GPIOLIB 739a7f7f624SMasahiro Yamada help 74083125a3aSAlessandro Rubini This adds support for boards based on the STA2X11 IO-Hub, 74183125a3aSAlessandro Rubini a.k.a. "ConneXt". The chip is used in place of the standard 74283125a3aSAlessandro Rubini PC chipset, so all "standard" peripherals are missing. If this 74383125a3aSAlessandro Rubini option is selected the kernel will still be able to boot on 74483125a3aSAlessandro Rubini standard PC machines. 74583125a3aSAlessandro Rubini 74682148d1dSShérabconfig X86_32_IRIS 74782148d1dSShérab tristate "Eurobraille/Iris poweroff module" 74882148d1dSShérab depends on X86_32 749a7f7f624SMasahiro Yamada help 75082148d1dSShérab The Iris machines from EuroBraille do not have APM or ACPI support 75182148d1dSShérab to shut themselves down properly. A special I/O sequence is 75282148d1dSShérab needed to do so, which is what this module does at 75382148d1dSShérab kernel shutdown. 75482148d1dSShérab 75582148d1dSShérab This is only for Iris machines from EuroBraille. 75682148d1dSShérab 75782148d1dSShérab If unused, say N. 75882148d1dSShérab 759ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER 7603c2362e6SHarvey Harrison def_bool y 7613c2362e6SHarvey Harrison prompt "Single-depth WCHAN output" 762a87d0914SKen Chen depends on X86 763a7f7f624SMasahiro Yamada help 764506f1d07SSam Ravnborg Calculate simpler /proc/<PID>/wchan values. If this option 765506f1d07SSam Ravnborg is disabled then wchan values will recurse back to the 766506f1d07SSam Ravnborg caller function. This provides more accurate wchan values, 767506f1d07SSam Ravnborg at the expense of slightly more scheduling overhead. 768506f1d07SSam Ravnborg 769506f1d07SSam Ravnborg If in doubt, say "Y". 770506f1d07SSam Ravnborg 7716276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST 7726276a074SBorislav Petkov bool "Linux guest support" 773a7f7f624SMasahiro Yamada help 7746276a074SBorislav Petkov Say Y here to enable options for running Linux under various hyper- 7756276a074SBorislav Petkov visors. This option enables basic hypervisor detection and platform 7766276a074SBorislav Petkov setup. 777506f1d07SSam Ravnborg 7786276a074SBorislav Petkov If you say N, all options in this submenu will be skipped and 7796276a074SBorislav Petkov disabled, and Linux guest support won't be built in. 780506f1d07SSam Ravnborg 7816276a074SBorislav Petkovif HYPERVISOR_GUEST 782506f1d07SSam Ravnborg 783e61bd94aSEduardo Pereira Habkostconfig PARAVIRT 784e61bd94aSEduardo Pereira Habkost bool "Enable paravirtualization code" 785a0e2bf7cSJuergen Gross depends on HAVE_STATIC_CALL 786a7f7f624SMasahiro Yamada help 787e61bd94aSEduardo Pereira Habkost This changes the kernel so it can modify itself when it is run 788e61bd94aSEduardo Pereira Habkost under a hypervisor, potentially improving performance significantly 789e61bd94aSEduardo Pereira Habkost over full virtualization. However, when run without a hypervisor 790e61bd94aSEduardo Pereira Habkost the kernel is theoretically slower and slightly larger. 791e61bd94aSEduardo Pereira Habkost 792c00a280aSJuergen Grossconfig PARAVIRT_XXL 793c00a280aSJuergen Gross bool 794c00a280aSJuergen Gross 7956276a074SBorislav Petkovconfig PARAVIRT_DEBUG 7966276a074SBorislav Petkov bool "paravirt-ops debugging" 7976276a074SBorislav Petkov depends on PARAVIRT && DEBUG_KERNEL 798a7f7f624SMasahiro Yamada help 7996276a074SBorislav Petkov Enable to debug paravirt_ops internals. Specifically, BUG if 8006276a074SBorislav Petkov a paravirt_op is missing when it is called. 8016276a074SBorislav Petkov 802b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS 803b4ecc126SJeremy Fitzhardinge bool "Paravirtualization layer for spinlocks" 8046ea30386SKees Cook depends on PARAVIRT && SMP 805a7f7f624SMasahiro Yamada help 806b4ecc126SJeremy Fitzhardinge Paravirtualized spinlocks allow a pvops backend to replace the 807b4ecc126SJeremy Fitzhardinge spinlock implementation with something virtualization-friendly 808b4ecc126SJeremy Fitzhardinge (for example, block the virtual CPU rather than spinning). 809b4ecc126SJeremy Fitzhardinge 8104c4e4f61SRaghavendra K T It has a minimal impact on native kernels and gives a nice performance 8114c4e4f61SRaghavendra K T benefit on paravirtualized KVM / Xen kernels. 812b4ecc126SJeremy Fitzhardinge 8134c4e4f61SRaghavendra K T If you are unsure how to answer this question, answer Y. 814b4ecc126SJeremy Fitzhardinge 815ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR 816ecca2502SZhao Yakui def_bool n 817ecca2502SZhao Yakui 8186276a074SBorislav Petkovsource "arch/x86/xen/Kconfig" 8196276a074SBorislav Petkov 8206276a074SBorislav Petkovconfig KVM_GUEST 8216276a074SBorislav Petkov bool "KVM Guest support (including kvmclock)" 8226276a074SBorislav Petkov depends on PARAVIRT 8236276a074SBorislav Petkov select PARAVIRT_CLOCK 824a1c4423bSMarcelo Tosatti select ARCH_CPUIDLE_HALTPOLL 825b1d40575SVitaly Kuznetsov select X86_HV_CALLBACK_VECTOR 8266276a074SBorislav Petkov default y 827a7f7f624SMasahiro Yamada help 8286276a074SBorislav Petkov This option enables various optimizations for running under the KVM 8296276a074SBorislav Petkov hypervisor. It includes a paravirtualized clock, so that instead 8306276a074SBorislav Petkov of relying on a PIT (or probably other) emulation by the 8316276a074SBorislav Petkov underlying device model, the host provides the guest with 8326276a074SBorislav Petkov timing infrastructure such as time of day, and system time 8336276a074SBorislav Petkov 834a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL 835a1c4423bSMarcelo Tosatti def_bool n 836a1c4423bSMarcelo Tosatti prompt "Disable host haltpoll when loading haltpoll driver" 837a1c4423bSMarcelo Tosatti help 838a1c4423bSMarcelo Tosatti If virtualized under KVM, disable host haltpoll. 839a1c4423bSMarcelo Tosatti 8407733607fSMaran Wilsonconfig PVH 8417733607fSMaran Wilson bool "Support for running PVH guests" 842a7f7f624SMasahiro Yamada help 8437733607fSMaran Wilson This option enables the PVH entry point for guest virtual machines 8447733607fSMaran Wilson as specified in the x86/HVM direct boot ABI. 8457733607fSMaran Wilson 8466276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING 8476276a074SBorislav Petkov bool "Paravirtual steal time accounting" 8486276a074SBorislav Petkov depends on PARAVIRT 849a7f7f624SMasahiro Yamada help 8506276a074SBorislav Petkov Select this option to enable fine granularity task steal time 8516276a074SBorislav Petkov accounting. Time spent executing other tasks in parallel with 8526276a074SBorislav Petkov the current vCPU is discounted from the vCPU power. To account for 8536276a074SBorislav Petkov that, there can be a small performance impact. 8546276a074SBorislav Petkov 8556276a074SBorislav Petkov If in doubt, say N here. 8566276a074SBorislav Petkov 8577af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK 8587af192c9SGerd Hoffmann bool 8597af192c9SGerd Hoffmann 8604a362601SJan Kiszkaconfig JAILHOUSE_GUEST 8614a362601SJan Kiszka bool "Jailhouse non-root cell support" 862abde587bSArnd Bergmann depends on X86_64 && PCI 86387e65d05SJan Kiszka select X86_PM_TIMER 864a7f7f624SMasahiro Yamada help 8654a362601SJan Kiszka This option allows to run Linux as guest in a Jailhouse non-root 8664a362601SJan Kiszka cell. You can leave this option disabled if you only want to start 8674a362601SJan Kiszka Jailhouse and run Linux afterwards in the root cell. 8684a362601SJan Kiszka 869ec7972c9SZhao Yakuiconfig ACRN_GUEST 870ec7972c9SZhao Yakui bool "ACRN Guest support" 871ec7972c9SZhao Yakui depends on X86_64 872498ad393SZhao Yakui select X86_HV_CALLBACK_VECTOR 873ec7972c9SZhao Yakui help 874ec7972c9SZhao Yakui This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 875ec7972c9SZhao Yakui a flexible, lightweight reference open-source hypervisor, built with 876ec7972c9SZhao Yakui real-time and safety-criticality in mind. It is built for embedded 877ec7972c9SZhao Yakui IOT with small footprint and real-time features. More details can be 878ec7972c9SZhao Yakui found in https://projectacrn.org/. 879ec7972c9SZhao Yakui 88059bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST 88159bd54a8SKuppuswamy Sathyanarayanan bool "Intel TDX (Trust Domain Extensions) - Guest Support" 88259bd54a8SKuppuswamy Sathyanarayanan depends on X86_64 && CPU_SUP_INTEL 88359bd54a8SKuppuswamy Sathyanarayanan depends on X86_X2APIC 88475d090fdSKirill A. Shutemov depends on EFI_STUB 88541394e33SKirill A. Shutemov select ARCH_HAS_CC_PLATFORM 886968b4931SKirill A. Shutemov select X86_MEM_ENCRYPT 88777a512e3SSean Christopherson select X86_MCE 88875d090fdSKirill A. Shutemov select UNACCEPTED_MEMORY 88959bd54a8SKuppuswamy Sathyanarayanan help 89059bd54a8SKuppuswamy Sathyanarayanan Support running as a guest under Intel TDX. Without this support, 89159bd54a8SKuppuswamy Sathyanarayanan the guest kernel can not boot or run under TDX. 89259bd54a8SKuppuswamy Sathyanarayanan TDX includes memory encryption and integrity capabilities 89359bd54a8SKuppuswamy Sathyanarayanan which protect the confidentiality and integrity of guest 89459bd54a8SKuppuswamy Sathyanarayanan memory contents and CPU state. TDX guests are protected from 89559bd54a8SKuppuswamy Sathyanarayanan some attacks from the VMM. 89659bd54a8SKuppuswamy Sathyanarayanan 8976276a074SBorislav Petkovendif # HYPERVISOR_GUEST 89897349135SJeremy Fitzhardinge 899506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu" 900506f1d07SSam Ravnborg 901506f1d07SSam Ravnborgconfig HPET_TIMER 9023c2362e6SHarvey Harrison def_bool X86_64 903506f1d07SSam Ravnborg prompt "HPET Timer Support" if X86_32 904a7f7f624SMasahiro Yamada help 905506f1d07SSam Ravnborg Use the IA-PC HPET (High Precision Event Timer) to manage 906506f1d07SSam Ravnborg time in preference to the PIT and RTC, if a HPET is 907506f1d07SSam Ravnborg present. 908506f1d07SSam Ravnborg HPET is the next generation timer replacing legacy 8254s. 909506f1d07SSam Ravnborg The HPET provides a stable time base on SMP 910506f1d07SSam Ravnborg systems, unlike the TSC, but it is more expensive to access, 9114e7f9df2SMichael S. Tsirkin as it is off-chip. The interface used is documented 9124e7f9df2SMichael S. Tsirkin in the HPET spec, revision 1. 913506f1d07SSam Ravnborg 914506f1d07SSam Ravnborg You can safely choose Y here. However, HPET will only be 915506f1d07SSam Ravnborg activated if the platform and the BIOS support this feature. 916506f1d07SSam Ravnborg Otherwise the 8254 will be used for timing services. 917506f1d07SSam Ravnborg 918506f1d07SSam Ravnborg Choose N to continue using the legacy 8254 timer. 919506f1d07SSam Ravnborg 920506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC 9213c2362e6SHarvey Harrison def_bool y 9223228e1dcSAnand K Mistry depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 923506f1d07SSam Ravnborg 9246a108a14SDavid Rientjes# Mark as expert because too many people got it wrong. 925506f1d07SSam Ravnborg# The code disables itself when not needed. 9267ae9392cSThomas Petazzoniconfig DMI 9277ae9392cSThomas Petazzoni default y 928cf074402SArd Biesheuvel select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 9296a108a14SDavid Rientjes bool "Enable DMI scanning" if EXPERT 930a7f7f624SMasahiro Yamada help 9317ae9392cSThomas Petazzoni Enabled scanning of DMI to identify machine quirks. Say Y 9327ae9392cSThomas Petazzoni here unless you have verified that your setup is not 9337ae9392cSThomas Petazzoni affected by entries in the DMI blacklist. Required by PNP 9347ae9392cSThomas Petazzoni BIOS code. 9357ae9392cSThomas Petazzoni 936506f1d07SSam Ravnborgconfig GART_IOMMU 93738901f1cSAndi Kleen bool "Old AMD GART IOMMU support" 9382f9237d4SChristoph Hellwig select DMA_OPS 939a4ce5a48SChristoph Hellwig select IOMMU_HELPER 940506f1d07SSam Ravnborg select SWIOTLB 94123ac4ae8SAndreas Herrmann depends on X86_64 && PCI && AMD_NB 942a7f7f624SMasahiro Yamada help 943ced3c42cSIngo Molnar Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 944ced3c42cSIngo Molnar GART based hardware IOMMUs. 945ced3c42cSIngo Molnar 946ced3c42cSIngo Molnar The GART supports full DMA access for devices with 32-bit access 947ced3c42cSIngo Molnar limitations, on systems with more than 3 GB. This is usually needed 948ced3c42cSIngo Molnar for USB, sound, many IDE/SATA chipsets and some other devices. 949ced3c42cSIngo Molnar 950ced3c42cSIngo Molnar Newer systems typically have a modern AMD IOMMU, supported via 951ced3c42cSIngo Molnar the CONFIG_AMD_IOMMU=y config option. 952ced3c42cSIngo Molnar 953ced3c42cSIngo Molnar In normal configurations this driver is only active when needed: 954ced3c42cSIngo Molnar there's more than 3 GB of memory and the system contains a 955ced3c42cSIngo Molnar 32-bit limited device. 956ced3c42cSIngo Molnar 957ced3c42cSIngo Molnar If unsure, say Y. 958506f1d07SSam Ravnborg 9598b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT 9608b766b0fSMichal Suchanek bool 9618b766b0fSMichal Suchanek help 9628b766b0fSMichal Suchanek If true, at least one selected framebuffer driver can take advantage 9638b766b0fSMichal Suchanek of VESA video modes set at an early boot stage via the vga= parameter. 9648b766b0fSMichal Suchanek 9651184dc2fSMike Travisconfig MAXSMP 966ddb0c5a6SSamuel Thibault bool "Enable Maximum number of SMP Processors and NUMA Nodes" 9676ea30386SKees Cook depends on X86_64 && SMP && DEBUG_KERNEL 96836f5101aSMike Travis select CPUMASK_OFFSTACK 969a7f7f624SMasahiro Yamada help 970ddb0c5a6SSamuel Thibault Enable maximum number of CPUS and NUMA Nodes for this architecture. 9711184dc2fSMike Travis If unsure, say N. 972506f1d07SSam Ravnborg 973aec6487eSIngo Molnar# 974aec6487eSIngo Molnar# The maximum number of CPUs supported: 975aec6487eSIngo Molnar# 976aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 977aec6487eSIngo Molnar# and which can be configured interactively in the 978aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 979aec6487eSIngo Molnar# 980aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on 981aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel. 982aec6487eSIngo Molnar# 983aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable 984aec6487eSIngo Molnar# interactive configuration. ) 985aec6487eSIngo Molnar# 986a0d0bb4dSRandy Dunlap 987aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN 988a0d0bb4dSRandy Dunlap int 989aec6487eSIngo Molnar default NR_CPUS_RANGE_END if MAXSMP 990a0d0bb4dSRandy Dunlap default 1 if !SMP 991a0d0bb4dSRandy Dunlap default 2 992a0d0bb4dSRandy Dunlap 993aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 994a0d0bb4dSRandy Dunlap int 995a0d0bb4dSRandy Dunlap depends on X86_32 996aec6487eSIngo Molnar default 64 if SMP && X86_BIGSMP 997aec6487eSIngo Molnar default 8 if SMP && !X86_BIGSMP 998a0d0bb4dSRandy Dunlap default 1 if !SMP 999a0d0bb4dSRandy Dunlap 1000aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END 1001a0d0bb4dSRandy Dunlap int 1002a0d0bb4dSRandy Dunlap depends on X86_64 10031edae1aeSScott Wood default 8192 if SMP && CPUMASK_OFFSTACK 10041edae1aeSScott Wood default 512 if SMP && !CPUMASK_OFFSTACK 1005a0d0bb4dSRandy Dunlap default 1 if !SMP 1006aec6487eSIngo Molnar 1007aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 1008aec6487eSIngo Molnar int 1009aec6487eSIngo Molnar depends on X86_32 1010aec6487eSIngo Molnar default 32 if X86_BIGSMP 1011aec6487eSIngo Molnar default 8 if SMP 1012aec6487eSIngo Molnar default 1 if !SMP 1013aec6487eSIngo Molnar 1014aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT 1015aec6487eSIngo Molnar int 1016aec6487eSIngo Molnar depends on X86_64 1017a0d0bb4dSRandy Dunlap default 8192 if MAXSMP 1018a0d0bb4dSRandy Dunlap default 64 if SMP 1019aec6487eSIngo Molnar default 1 if !SMP 1020a0d0bb4dSRandy Dunlap 1021506f1d07SSam Ravnborgconfig NR_CPUS 102236f5101aSMike Travis int "Maximum number of CPUs" if SMP && !MAXSMP 1023aec6487eSIngo Molnar range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1024aec6487eSIngo Molnar default NR_CPUS_DEFAULT 1025a7f7f624SMasahiro Yamada help 1026506f1d07SSam Ravnborg This allows you to specify the maximum number of CPUs which this 1027bb61ccc7SJosh Boyer kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1028cad14bb9SKirill A. Shutemov supported value is 8192, otherwise the maximum value is 512. The 1029506f1d07SSam Ravnborg minimum value which makes sense is 2. 1030506f1d07SSam Ravnborg 1031aec6487eSIngo Molnar This is purely to save memory: each supported CPU adds about 8KB 1032aec6487eSIngo Molnar to the kernel image. 1033506f1d07SSam Ravnborg 103466558b73STim Chenconfig SCHED_CLUSTER 103566558b73STim Chen bool "Cluster scheduler support" 103666558b73STim Chen depends on SMP 103766558b73STim Chen default y 103866558b73STim Chen help 103966558b73STim Chen Cluster scheduler support improves the CPU scheduler's decision 104066558b73STim Chen making when dealing with machines that have clusters of CPUs. 104166558b73STim Chen Cluster usually means a couple of CPUs which are placed closely 104266558b73STim Chen by sharing mid-level caches, last-level cache tags or internal 104366558b73STim Chen busses. 104466558b73STim Chen 1045506f1d07SSam Ravnborgconfig SCHED_SMT 1046dbe73364SThomas Gleixner def_bool y if SMP 1047506f1d07SSam Ravnborg 1048506f1d07SSam Ravnborgconfig SCHED_MC 10493c2362e6SHarvey Harrison def_bool y 10503c2362e6SHarvey Harrison prompt "Multi-core scheduler support" 1051c8e56d20SBorislav Petkov depends on SMP 1052a7f7f624SMasahiro Yamada help 1053506f1d07SSam Ravnborg Multi-core scheduler support improves the CPU scheduler's decision 1054506f1d07SSam Ravnborg making when dealing with multi-core CPU chips at a cost of slightly 1055506f1d07SSam Ravnborg increased overhead in some places. If unsure say N here. 1056506f1d07SSam Ravnborg 1057de966cf4STim Chenconfig SCHED_MC_PRIO 1058de966cf4STim Chen bool "CPU core priorities scheduler support" 10590a21fc12SIngo Molnar depends on SCHED_MC && CPU_SUP_INTEL 10600a21fc12SIngo Molnar select X86_INTEL_PSTATE 10610a21fc12SIngo Molnar select CPU_FREQ 1062de966cf4STim Chen default y 1063a7f7f624SMasahiro Yamada help 1064de966cf4STim Chen Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1065de966cf4STim Chen core ordering determined at manufacturing time, which allows 1066de966cf4STim Chen certain cores to reach higher turbo frequencies (when running 1067de966cf4STim Chen single threaded workloads) than others. 1068de966cf4STim Chen 1069de966cf4STim Chen Enabling this kernel feature teaches the scheduler about 1070de966cf4STim Chen the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1071de966cf4STim Chen scheduler's CPU selection logic accordingly, so that higher 1072de966cf4STim Chen overall system performance can be achieved. 1073de966cf4STim Chen 1074de966cf4STim Chen This feature will have no effect on CPUs without this feature. 1075de966cf4STim Chen 1076de966cf4STim Chen If unsure say Y here. 10775e76b2abSTim Chen 107830b8b006SThomas Gleixnerconfig UP_LATE_INIT 107930b8b006SThomas Gleixner def_bool y 1080ba360f88SThomas Gleixner depends on !SMP && X86_LOCAL_APIC 108130b8b006SThomas Gleixner 1082506f1d07SSam Ravnborgconfig X86_UP_APIC 108350849eefSJan Beulich bool "Local APIC support on uniprocessors" if !PCI_MSI 108450849eefSJan Beulich default PCI_MSI 108538a1dfdaSBryan O'Donoghue depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1086a7f7f624SMasahiro Yamada help 1087506f1d07SSam Ravnborg A local APIC (Advanced Programmable Interrupt Controller) is an 1088506f1d07SSam Ravnborg integrated interrupt controller in the CPU. If you have a single-CPU 1089506f1d07SSam Ravnborg system which has a processor with a local APIC, you can say Y here to 1090506f1d07SSam Ravnborg enable and use it. If you say Y here even though your machine doesn't 1091506f1d07SSam Ravnborg have a local APIC, then the kernel will still run with no slowdown at 1092506f1d07SSam Ravnborg all. The local APIC supports CPU-generated self-interrupts (timer, 1093506f1d07SSam Ravnborg performance counters), and the NMI watchdog which detects hard 1094506f1d07SSam Ravnborg lockups. 1095506f1d07SSam Ravnborg 1096506f1d07SSam Ravnborgconfig X86_UP_IOAPIC 1097506f1d07SSam Ravnborg bool "IO-APIC support on uniprocessors" 1098506f1d07SSam Ravnborg depends on X86_UP_APIC 1099a7f7f624SMasahiro Yamada help 1100506f1d07SSam Ravnborg An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1101506f1d07SSam Ravnborg SMP-capable replacement for PC-style interrupt controllers. Most 1102506f1d07SSam Ravnborg SMP systems and many recent uniprocessor systems have one. 1103506f1d07SSam Ravnborg 1104506f1d07SSam Ravnborg If you have a single-CPU system with an IO-APIC, you can say Y here 1105506f1d07SSam Ravnborg to use it. If you say Y here even though your machine doesn't have 1106506f1d07SSam Ravnborg an IO-APIC, then the kernel will still run with no slowdown at all. 1107506f1d07SSam Ravnborg 1108506f1d07SSam Ravnborgconfig X86_LOCAL_APIC 11093c2362e6SHarvey Harrison def_bool y 11100dbc6078SThomas Petazzoni depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1111b5dc8e6cSJiang Liu select IRQ_DOMAIN_HIERARCHY 1112506f1d07SSam Ravnborg 1113506f1d07SSam Ravnborgconfig X86_IO_APIC 1114b1da1e71SJan Beulich def_bool y 1115b1da1e71SJan Beulich depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1116506f1d07SSam Ravnborg 111741b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS 111841b9eb26SStefan Assmann bool "Reroute for broken boot IRQs" 111941b9eb26SStefan Assmann depends on X86_IO_APIC 1120a7f7f624SMasahiro Yamada help 112141b9eb26SStefan Assmann This option enables a workaround that fixes a source of 112241b9eb26SStefan Assmann spurious interrupts. This is recommended when threaded 112341b9eb26SStefan Assmann interrupt handling is used on systems where the generation of 112441b9eb26SStefan Assmann superfluous "boot interrupts" cannot be disabled. 112541b9eb26SStefan Assmann 112641b9eb26SStefan Assmann Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 112741b9eb26SStefan Assmann entry in the chipset's IO-APIC is masked (as, e.g. the RT 112841b9eb26SStefan Assmann kernel does during interrupt handling). On chipsets where this 112941b9eb26SStefan Assmann boot IRQ generation cannot be disabled, this workaround keeps 113041b9eb26SStefan Assmann the original IRQ line masked so that only the equivalent "boot 113141b9eb26SStefan Assmann IRQ" is delivered to the CPUs. The workaround also tells the 113241b9eb26SStefan Assmann kernel to set up the IRQ handler on the boot IRQ line. In this 113341b9eb26SStefan Assmann way only one interrupt is delivered to the kernel. Otherwise 113441b9eb26SStefan Assmann the spurious second interrupt may cause the kernel to bring 113541b9eb26SStefan Assmann down (vital) interrupt lines. 113641b9eb26SStefan Assmann 113741b9eb26SStefan Assmann Only affects "broken" chipsets. Interrupt sharing may be 113841b9eb26SStefan Assmann increased on these systems. 113941b9eb26SStefan Assmann 1140506f1d07SSam Ravnborgconfig X86_MCE 1141bab9bc65SAndi Kleen bool "Machine Check / overheating reporting" 1142648ed940SChen, Gong select GENERIC_ALLOCATOR 1143e57dbaf7SBorislav Petkov default y 1144a7f7f624SMasahiro Yamada help 1145bab9bc65SAndi Kleen Machine Check support allows the processor to notify the 1146bab9bc65SAndi Kleen kernel if it detects a problem (e.g. overheating, data corruption). 1147506f1d07SSam Ravnborg The action the kernel takes depends on the severity of the problem, 1148bab9bc65SAndi Kleen ranging from warning messages to halting the machine. 11494efc0670SAndi Kleen 11505de97c9fSTony Luckconfig X86_MCELOG_LEGACY 11515de97c9fSTony Luck bool "Support for deprecated /dev/mcelog character device" 11525de97c9fSTony Luck depends on X86_MCE 1153a7f7f624SMasahiro Yamada help 11545de97c9fSTony Luck Enable support for /dev/mcelog which is needed by the old mcelog 11555de97c9fSTony Luck userspace logging daemon. Consider switching to the new generation 11565de97c9fSTony Luck rasdaemon solution. 11575de97c9fSTony Luck 1158506f1d07SSam Ravnborgconfig X86_MCE_INTEL 11593c2362e6SHarvey Harrison def_bool y 11603c2362e6SHarvey Harrison prompt "Intel MCE features" 1161c1ebf835SAndi Kleen depends on X86_MCE && X86_LOCAL_APIC 1162a7f7f624SMasahiro Yamada help 1163506f1d07SSam Ravnborg Additional support for intel specific MCE features such as 1164506f1d07SSam Ravnborg the thermal monitor. 1165506f1d07SSam Ravnborg 1166506f1d07SSam Ravnborgconfig X86_MCE_AMD 11673c2362e6SHarvey Harrison def_bool y 11683c2362e6SHarvey Harrison prompt "AMD MCE features" 1169f5382de9SYazen Ghannam depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1170a7f7f624SMasahiro Yamada help 1171506f1d07SSam Ravnborg Additional support for AMD specific MCE features such as 1172506f1d07SSam Ravnborg the DRAM Error Threshold. 1173506f1d07SSam Ravnborg 11744efc0670SAndi Kleenconfig X86_ANCIENT_MCE 11756fc108a0SJan Beulich bool "Support for old Pentium 5 / WinChip machine checks" 1176c31d9633SAndi Kleen depends on X86_32 && X86_MCE 1177a7f7f624SMasahiro Yamada help 11784efc0670SAndi Kleen Include support for machine check handling on old Pentium 5 or WinChip 11795065a706SMasanari Iida systems. These typically need to be enabled explicitly on the command 11804efc0670SAndi Kleen line. 11814efc0670SAndi Kleen 1182b2762686SAndi Kleenconfig X86_MCE_THRESHOLD 1183b2762686SAndi Kleen depends on X86_MCE_AMD || X86_MCE_INTEL 11846fc108a0SJan Beulich def_bool y 1185b2762686SAndi Kleen 1186ea149b36SAndi Kleenconfig X86_MCE_INJECT 1187bc8e80d5SBorislav Petkov depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1188ea149b36SAndi Kleen tristate "Machine check injector support" 1189a7f7f624SMasahiro Yamada help 1190ea149b36SAndi Kleen Provide support for injecting machine checks for testing purposes. 1191ea149b36SAndi Kleen If you don't know what a machine check is and you don't do kernel 1192ea149b36SAndi Kleen QA it is safe to say n. 1193ea149b36SAndi Kleen 119407dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig" 1195e633c65aSKan Liang 11965aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86 11971e642812SIngo Molnar bool "Legacy VM86 support" 1198506f1d07SSam Ravnborg depends on X86_32 1199a7f7f624SMasahiro Yamada help 12005aef51c3SAndy Lutomirski This option allows user programs to put the CPU into V8086 12015aef51c3SAndy Lutomirski mode, which is an 80286-era approximation of 16-bit real mode. 12025aef51c3SAndy Lutomirski 12035aef51c3SAndy Lutomirski Some very old versions of X and/or vbetool require this option 12045aef51c3SAndy Lutomirski for user mode setting. Similarly, DOSEMU will use it if 12055aef51c3SAndy Lutomirski available to accelerate real mode DOS programs. However, any 12065aef51c3SAndy Lutomirski recent version of DOSEMU, X, or vbetool should be fully 12075aef51c3SAndy Lutomirski functional even without kernel VM86 support, as they will all 12081e642812SIngo Molnar fall back to software emulation. Nevertheless, if you are using 12091e642812SIngo Molnar a 16-bit DOS program where 16-bit performance matters, vm86 12101e642812SIngo Molnar mode might be faster than emulation and you might want to 12111e642812SIngo Molnar enable this option. 12125aef51c3SAndy Lutomirski 12131e642812SIngo Molnar Note that any app that works on a 64-bit kernel is unlikely to 12141e642812SIngo Molnar need this option, as 64-bit kernels don't, and can't, support 12151e642812SIngo Molnar V8086 mode. This option is also unrelated to 16-bit protected 12161e642812SIngo Molnar mode and is not needed to run most 16-bit programs under Wine. 12175aef51c3SAndy Lutomirski 12181e642812SIngo Molnar Enabling this option increases the complexity of the kernel 12191e642812SIngo Molnar and slows down exception handling a tiny bit. 12205aef51c3SAndy Lutomirski 12211e642812SIngo Molnar If unsure, say N here. 12225aef51c3SAndy Lutomirski 12235aef51c3SAndy Lutomirskiconfig VM86 12245aef51c3SAndy Lutomirski bool 12255aef51c3SAndy Lutomirski default X86_LEGACY_VM86 122634273f41SH. Peter Anvin 122734273f41SH. Peter Anvinconfig X86_16BIT 122834273f41SH. Peter Anvin bool "Enable support for 16-bit segments" if EXPERT 122934273f41SH. Peter Anvin default y 1230a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 1231a7f7f624SMasahiro Yamada help 123234273f41SH. Peter Anvin This option is required by programs like Wine to run 16-bit 123334273f41SH. Peter Anvin protected mode legacy code on x86 processors. Disabling 123434273f41SH. Peter Anvin this option saves about 300 bytes on i386, or around 6K text 123534273f41SH. Peter Anvin plus 16K runtime memory on x86-64, 123634273f41SH. Peter Anvin 123734273f41SH. Peter Anvinconfig X86_ESPFIX32 123834273f41SH. Peter Anvin def_bool y 123934273f41SH. Peter Anvin depends on X86_16BIT && X86_32 1240506f1d07SSam Ravnborg 1241197725deSH. Peter Anvinconfig X86_ESPFIX64 1242197725deSH. Peter Anvin def_bool y 124334273f41SH. Peter Anvin depends on X86_16BIT && X86_64 1244506f1d07SSam Ravnborg 12451ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION 12461ad83c85SAndy Lutomirski bool "Enable vsyscall emulation" if EXPERT 12471ad83c85SAndy Lutomirski default y 12481ad83c85SAndy Lutomirski depends on X86_64 1249a7f7f624SMasahiro Yamada help 12501ad83c85SAndy Lutomirski This enables emulation of the legacy vsyscall page. Disabling 12511ad83c85SAndy Lutomirski it is roughly equivalent to booting with vsyscall=none, except 12521ad83c85SAndy Lutomirski that it will also disable the helpful warning if a program 12531ad83c85SAndy Lutomirski tries to use a vsyscall. With this option set to N, offending 12541ad83c85SAndy Lutomirski programs will just segfault, citing addresses of the form 12551ad83c85SAndy Lutomirski 0xffffffffff600?00. 12561ad83c85SAndy Lutomirski 12571ad83c85SAndy Lutomirski This option is required by many programs built before 2013, and 12581ad83c85SAndy Lutomirski care should be used even with newer programs if set to N. 12591ad83c85SAndy Lutomirski 12601ad83c85SAndy Lutomirski Disabling this option saves about 7K of kernel size and 12611ad83c85SAndy Lutomirski possibly 4K of additional runtime pagetable memory. 12621ad83c85SAndy Lutomirski 1263111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM 1264111e7b15SThomas Gleixner bool "IOPERM and IOPL Emulation" 1265a24ca997SThomas Gleixner default y 1266a7f7f624SMasahiro Yamada help 1267111e7b15SThomas Gleixner This enables the ioperm() and iopl() syscalls which are necessary 1268111e7b15SThomas Gleixner for legacy applications. 1269111e7b15SThomas Gleixner 1270c8137aceSThomas Gleixner Legacy IOPL support is an overbroad mechanism which allows user 1271c8137aceSThomas Gleixner space aside of accessing all 65536 I/O ports also to disable 1272c8137aceSThomas Gleixner interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1273c8137aceSThomas Gleixner capabilities and permission from potentially active security 1274c8137aceSThomas Gleixner modules. 1275c8137aceSThomas Gleixner 1276c8137aceSThomas Gleixner The emulation restricts the functionality of the syscall to 1277c8137aceSThomas Gleixner only allowing the full range I/O port access, but prevents the 1278a24ca997SThomas Gleixner ability to disable interrupts from user space which would be 1279a24ca997SThomas Gleixner granted if the hardware IOPL mechanism would be used. 1280c8137aceSThomas Gleixner 1281506f1d07SSam Ravnborgconfig TOSHIBA 1282506f1d07SSam Ravnborg tristate "Toshiba Laptop support" 1283506f1d07SSam Ravnborg depends on X86_32 1284a7f7f624SMasahiro Yamada help 1285506f1d07SSam Ravnborg This adds a driver to safely access the System Management Mode of 1286506f1d07SSam Ravnborg the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1287506f1d07SSam Ravnborg not work on models with a Phoenix BIOS. The System Management Mode 1288506f1d07SSam Ravnborg is used to set the BIOS and power saving options on Toshiba portables. 1289506f1d07SSam Ravnborg 1290506f1d07SSam Ravnborg For information on utilities to make use of this driver see the 1291506f1d07SSam Ravnborg Toshiba Linux utilities web site at: 1292506f1d07SSam Ravnborg <http://www.buzzard.org.uk/toshiba/>. 1293506f1d07SSam Ravnborg 1294506f1d07SSam Ravnborg Say Y if you intend to run this kernel on a Toshiba portable. 1295506f1d07SSam Ravnborg Say N otherwise. 1296506f1d07SSam Ravnborg 1297506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS 12989ba16087SJan Beulich bool "Enable X86 board specific fixups for reboot" 12999ba16087SJan Beulich depends on X86_32 1300a7f7f624SMasahiro Yamada help 1301506f1d07SSam Ravnborg This enables chipset and/or board specific fixups to be done 1302506f1d07SSam Ravnborg in order to get reboot to work correctly. This is only needed on 1303506f1d07SSam Ravnborg some combinations of hardware and BIOS. The symptom, for which 1304506f1d07SSam Ravnborg this config is intended, is when reboot ends with a stalled/hung 1305506f1d07SSam Ravnborg system. 1306506f1d07SSam Ravnborg 1307506f1d07SSam Ravnborg Currently, the only fixup is for the Geode machines using 13085e3a77e9SFlorian Fainelli CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1309506f1d07SSam Ravnborg 1310506f1d07SSam Ravnborg Say Y if you want to enable the fixup. Currently, it's safe to 1311506f1d07SSam Ravnborg enable this option even if you don't need it. 1312506f1d07SSam Ravnborg Say N otherwise. 1313506f1d07SSam Ravnborg 1314506f1d07SSam Ravnborgconfig MICROCODE 1315e6bcfdd7SThomas Gleixner def_bool y 131680030e3dSBorislav Petkov depends on CPU_SUP_AMD || CPU_SUP_INTEL 131780cc9f10SPeter Oruba 1318fdbd4381SThomas Gleixnerconfig MICROCODE_INITRD32 1319fdbd4381SThomas Gleixner def_bool y 1320fdbd4381SThomas Gleixner depends on MICROCODE && X86_32 && BLK_DEV_INITRD 1321fdbd4381SThomas Gleixner 1322a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING 1323a77a94f8SBorislav Petkov bool "Late microcode loading (DANGEROUS)" 1324c02f48e0SBorislav Petkov default n 1325634ac23aSThomas Gleixner depends on MICROCODE && SMP 1326a7f7f624SMasahiro Yamada help 1327a77a94f8SBorislav Petkov Loading microcode late, when the system is up and executing instructions 1328a77a94f8SBorislav Petkov is a tricky business and should be avoided if possible. Just the sequence 1329a77a94f8SBorislav Petkov of synchronizing all cores and SMT threads is one fragile dance which does 1330a77a94f8SBorislav Petkov not guarantee that cores might not softlock after the loading. Therefore, 13319407bda8SThomas Gleixner use this at your own risk. Late loading taints the kernel unless the 13329407bda8SThomas Gleixner microcode header indicates that it is safe for late loading via the 13339407bda8SThomas Gleixner minimal revision check. This minimal revision check can be enforced on 13349407bda8SThomas Gleixner the kernel command line with "microcode.minrev=Y". 13359407bda8SThomas Gleixner 13369407bda8SThomas Gleixnerconfig MICROCODE_LATE_FORCE_MINREV 13379407bda8SThomas Gleixner bool "Enforce late microcode loading minimal revision check" 13389407bda8SThomas Gleixner default n 13399407bda8SThomas Gleixner depends on MICROCODE_LATE_LOADING 13409407bda8SThomas Gleixner help 13419407bda8SThomas Gleixner To prevent that users load microcode late which modifies already 13429407bda8SThomas Gleixner in use features, newer microcode patches have a minimum revision field 13439407bda8SThomas Gleixner in the microcode header, which tells the kernel which minimum 13449407bda8SThomas Gleixner revision must be active in the CPU to safely load that new microcode 13459407bda8SThomas Gleixner late into the running system. If disabled the check will not 13469407bda8SThomas Gleixner be enforced but the kernel will be tainted when the minimal 13479407bda8SThomas Gleixner revision check fails. 13489407bda8SThomas Gleixner 13499407bda8SThomas Gleixner This minimal revision check can also be controlled via the 13509407bda8SThomas Gleixner "microcode.minrev" parameter on the kernel command line. 13519407bda8SThomas Gleixner 13529407bda8SThomas Gleixner If unsure say Y. 1353506f1d07SSam Ravnborg 1354506f1d07SSam Ravnborgconfig X86_MSR 1355506f1d07SSam Ravnborg tristate "/dev/cpu/*/msr - Model-specific register support" 1356a7f7f624SMasahiro Yamada help 1357506f1d07SSam Ravnborg This device gives privileged processes access to the x86 1358506f1d07SSam Ravnborg Model-Specific Registers (MSRs). It is a character device with 1359506f1d07SSam Ravnborg major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1360506f1d07SSam Ravnborg MSR accesses are directed to a specific CPU on multi-processor 1361506f1d07SSam Ravnborg systems. 1362506f1d07SSam Ravnborg 1363506f1d07SSam Ravnborgconfig X86_CPUID 1364506f1d07SSam Ravnborg tristate "/dev/cpu/*/cpuid - CPU information support" 1365a7f7f624SMasahiro Yamada help 1366506f1d07SSam Ravnborg This device gives processes access to the x86 CPUID instruction to 1367506f1d07SSam Ravnborg be executed on a specific processor. It is a character device 1368506f1d07SSam Ravnborg with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1369506f1d07SSam Ravnborg /dev/cpu/31/cpuid. 1370506f1d07SSam Ravnborg 1371506f1d07SSam Ravnborgchoice 1372506f1d07SSam Ravnborg prompt "High Memory Support" 13736fc108a0SJan Beulich default HIGHMEM4G 1374506f1d07SSam Ravnborg depends on X86_32 1375506f1d07SSam Ravnborg 1376506f1d07SSam Ravnborgconfig NOHIGHMEM 1377506f1d07SSam Ravnborg bool "off" 1378a7f7f624SMasahiro Yamada help 1379506f1d07SSam Ravnborg Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1380506f1d07SSam Ravnborg However, the address space of 32-bit x86 processors is only 4 1381506f1d07SSam Ravnborg Gigabytes large. That means that, if you have a large amount of 1382506f1d07SSam Ravnborg physical memory, not all of it can be "permanently mapped" by the 1383506f1d07SSam Ravnborg kernel. The physical memory that's not permanently mapped is called 1384506f1d07SSam Ravnborg "high memory". 1385506f1d07SSam Ravnborg 1386506f1d07SSam Ravnborg If you are compiling a kernel which will never run on a machine with 1387506f1d07SSam Ravnborg more than 1 Gigabyte total physical RAM, answer "off" here (default 1388506f1d07SSam Ravnborg choice and suitable for most users). This will result in a "3GB/1GB" 1389506f1d07SSam Ravnborg split: 3GB are mapped so that each process sees a 3GB virtual memory 1390506f1d07SSam Ravnborg space and the remaining part of the 4GB virtual memory space is used 1391506f1d07SSam Ravnborg by the kernel to permanently map as much physical memory as 1392506f1d07SSam Ravnborg possible. 1393506f1d07SSam Ravnborg 1394506f1d07SSam Ravnborg If the machine has between 1 and 4 Gigabytes physical RAM, then 1395506f1d07SSam Ravnborg answer "4GB" here. 1396506f1d07SSam Ravnborg 1397506f1d07SSam Ravnborg If more than 4 Gigabytes is used then answer "64GB" here. This 1398506f1d07SSam Ravnborg selection turns Intel PAE (Physical Address Extension) mode on. 1399506f1d07SSam Ravnborg PAE implements 3-level paging on IA32 processors. PAE is fully 1400506f1d07SSam Ravnborg supported by Linux, PAE mode is implemented on all recent Intel 1401506f1d07SSam Ravnborg processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1402506f1d07SSam Ravnborg then the kernel will not boot on CPUs that don't support PAE! 1403506f1d07SSam Ravnborg 1404506f1d07SSam Ravnborg The actual amount of total physical memory will either be 1405506f1d07SSam Ravnborg auto detected or can be forced by using a kernel command line option 1406506f1d07SSam Ravnborg such as "mem=256M". (Try "man bootparam" or see the documentation of 1407506f1d07SSam Ravnborg your boot loader (lilo or loadlin) about how to pass options to the 1408506f1d07SSam Ravnborg kernel at boot time.) 1409506f1d07SSam Ravnborg 1410506f1d07SSam Ravnborg If unsure, say "off". 1411506f1d07SSam Ravnborg 1412506f1d07SSam Ravnborgconfig HIGHMEM4G 1413506f1d07SSam Ravnborg bool "4GB" 1414a7f7f624SMasahiro Yamada help 1415506f1d07SSam Ravnborg Select this if you have a 32-bit processor and between 1 and 4 1416506f1d07SSam Ravnborg gigabytes of physical RAM. 1417506f1d07SSam Ravnborg 1418506f1d07SSam Ravnborgconfig HIGHMEM64G 1419506f1d07SSam Ravnborg bool "64GB" 1420225bac2dSLukas Bulwahn depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6 1421506f1d07SSam Ravnborg select X86_PAE 1422a7f7f624SMasahiro Yamada help 1423506f1d07SSam Ravnborg Select this if you have a 32-bit processor and more than 4 1424506f1d07SSam Ravnborg gigabytes of physical RAM. 1425506f1d07SSam Ravnborg 1426506f1d07SSam Ravnborgendchoice 1427506f1d07SSam Ravnborg 1428506f1d07SSam Ravnborgchoice 14296a108a14SDavid Rientjes prompt "Memory split" if EXPERT 1430506f1d07SSam Ravnborg default VMSPLIT_3G 1431506f1d07SSam Ravnborg depends on X86_32 1432a7f7f624SMasahiro Yamada help 1433506f1d07SSam Ravnborg Select the desired split between kernel and user memory. 1434506f1d07SSam Ravnborg 1435506f1d07SSam Ravnborg If the address range available to the kernel is less than the 1436506f1d07SSam Ravnborg physical memory installed, the remaining memory will be available 1437506f1d07SSam Ravnborg as "high memory". Accessing high memory is a little more costly 1438506f1d07SSam Ravnborg than low memory, as it needs to be mapped into the kernel first. 1439506f1d07SSam Ravnborg Note that increasing the kernel address space limits the range 1440506f1d07SSam Ravnborg available to user programs, making the address space there 1441506f1d07SSam Ravnborg tighter. Selecting anything other than the default 3G/1G split 1442506f1d07SSam Ravnborg will also likely make your kernel incompatible with binary-only 1443506f1d07SSam Ravnborg kernel modules. 1444506f1d07SSam Ravnborg 1445506f1d07SSam Ravnborg If you are not absolutely sure what you are doing, leave this 1446506f1d07SSam Ravnborg option alone! 1447506f1d07SSam Ravnborg 1448506f1d07SSam Ravnborg config VMSPLIT_3G 1449506f1d07SSam Ravnborg bool "3G/1G user/kernel split" 1450506f1d07SSam Ravnborg config VMSPLIT_3G_OPT 1451506f1d07SSam Ravnborg depends on !X86_PAE 1452506f1d07SSam Ravnborg bool "3G/1G user/kernel split (for full 1G low memory)" 1453506f1d07SSam Ravnborg config VMSPLIT_2G 1454506f1d07SSam Ravnborg bool "2G/2G user/kernel split" 1455506f1d07SSam Ravnborg config VMSPLIT_2G_OPT 1456506f1d07SSam Ravnborg depends on !X86_PAE 1457506f1d07SSam Ravnborg bool "2G/2G user/kernel split (for full 2G low memory)" 1458506f1d07SSam Ravnborg config VMSPLIT_1G 1459506f1d07SSam Ravnborg bool "1G/3G user/kernel split" 1460506f1d07SSam Ravnborgendchoice 1461506f1d07SSam Ravnborg 1462506f1d07SSam Ravnborgconfig PAGE_OFFSET 1463506f1d07SSam Ravnborg hex 1464506f1d07SSam Ravnborg default 0xB0000000 if VMSPLIT_3G_OPT 1465506f1d07SSam Ravnborg default 0x80000000 if VMSPLIT_2G 1466506f1d07SSam Ravnborg default 0x78000000 if VMSPLIT_2G_OPT 1467506f1d07SSam Ravnborg default 0x40000000 if VMSPLIT_1G 1468506f1d07SSam Ravnborg default 0xC0000000 1469506f1d07SSam Ravnborg depends on X86_32 1470506f1d07SSam Ravnborg 1471506f1d07SSam Ravnborgconfig HIGHMEM 14723c2362e6SHarvey Harrison def_bool y 1473506f1d07SSam Ravnborg depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1474506f1d07SSam Ravnborg 1475506f1d07SSam Ravnborgconfig X86_PAE 14769ba16087SJan Beulich bool "PAE (Physical Address Extension) Support" 1477506f1d07SSam Ravnborg depends on X86_32 && !HIGHMEM4G 1478d4a451d5SChristoph Hellwig select PHYS_ADDR_T_64BIT 14799d99c712SChristian Melki select SWIOTLB 1480a7f7f624SMasahiro Yamada help 1481506f1d07SSam Ravnborg PAE is required for NX support, and furthermore enables 1482506f1d07SSam Ravnborg larger swapspace support for non-overcommit purposes. It 1483506f1d07SSam Ravnborg has the cost of more pagetable lookup overhead, and also 1484506f1d07SSam Ravnborg consumes more pagetable space per process. 1485506f1d07SSam Ravnborg 148677ef56e4SKirill A. Shutemovconfig X86_5LEVEL 148777ef56e4SKirill A. Shutemov bool "Enable 5-level page tables support" 148818ec1eafSKirill A. Shutemov default y 1489eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 1490162434e7SKirill A. Shutemov select SPARSEMEM_VMEMMAP 149177ef56e4SKirill A. Shutemov depends on X86_64 1492a7f7f624SMasahiro Yamada help 149377ef56e4SKirill A. Shutemov 5-level paging enables access to larger address space: 149477ef56e4SKirill A. Shutemov up to 128 PiB of virtual address space and 4 PiB of 149577ef56e4SKirill A. Shutemov physical address space. 149677ef56e4SKirill A. Shutemov 149777ef56e4SKirill A. Shutemov It will be supported by future Intel CPUs. 149877ef56e4SKirill A. Shutemov 14996657fca0SKirill A. Shutemov A kernel with the option enabled can be booted on machines that 15006657fca0SKirill A. Shutemov support 4- or 5-level paging. 150177ef56e4SKirill A. Shutemov 1502ff61f079SJonathan Corbet See Documentation/arch/x86/x86_64/5level-paging.rst for more 150377ef56e4SKirill A. Shutemov information. 150477ef56e4SKirill A. Shutemov 150577ef56e4SKirill A. Shutemov Say N if unsure. 150677ef56e4SKirill A. Shutemov 150710971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES 1508e5008abeSLuis R. Rodriguez def_bool y 15092e1da13fSVlastimil Babka depends on X86_64 1510a7f7f624SMasahiro Yamada help 151110971ab2SIngo Molnar Certain kernel features effectively disable kernel 151210971ab2SIngo Molnar linear 1 GB mappings (even if the CPU otherwise 151310971ab2SIngo Molnar supports them), so don't confuse the user by printing 151410971ab2SIngo Molnar that we have them enabled. 15159e899816SNick Piggin 15165c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS 15175c280cf6SThomas Gleixner bool "Enable statistic for Change Page Attribute" 15185c280cf6SThomas Gleixner depends on DEBUG_FS 1519a7f7f624SMasahiro Yamada help 1520b75baaf3SIngo Molnar Expose statistics about the Change Page Attribute mechanism, which 1521a943245aSColin Ian King helps to determine the effectiveness of preserving large and huge 15225c280cf6SThomas Gleixner page mappings when mapping protections are changed. 15235c280cf6SThomas Gleixner 152420f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT 152520f07a04SKirill A. Shutemov select ARCH_HAS_FORCE_DMA_UNENCRYPTED 152620f07a04SKirill A. Shutemov select DYNAMIC_PHYSICAL_MASK 152720f07a04SKirill A. Shutemov def_bool n 152820f07a04SKirill A. Shutemov 15297744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT 15307744ccdbSTom Lendacky bool "AMD Secure Memory Encryption (SME) support" 15317744ccdbSTom Lendacky depends on X86_64 && CPU_SUP_AMD 15326c321179STom Lendacky depends on EFI_STUB 153382fef0adSDavid Rientjes select DMA_COHERENT_POOL 1534ce9084baSArd Biesheuvel select ARCH_USE_MEMREMAP_PROT 1535597cfe48SJoerg Roedel select INSTRUCTION_DECODER 1536aa5a4611STom Lendacky select ARCH_HAS_CC_PLATFORM 153720f07a04SKirill A. Shutemov select X86_MEM_ENCRYPT 15386c321179STom Lendacky select UNACCEPTED_MEMORY 1539a7f7f624SMasahiro Yamada help 15407744ccdbSTom Lendacky Say yes to enable support for the encryption of system memory. 15417744ccdbSTom Lendacky This requires an AMD processor that supports Secure Memory 15427744ccdbSTom Lendacky Encryption (SME). 15437744ccdbSTom Lendacky 15447744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 15457744ccdbSTom Lendacky bool "Activate AMD Secure Memory Encryption (SME) by default" 15467744ccdbSTom Lendacky depends on AMD_MEM_ENCRYPT 1547a7f7f624SMasahiro Yamada help 15487744ccdbSTom Lendacky Say yes to have system memory encrypted by default if running on 15497744ccdbSTom Lendacky an AMD processor that supports Secure Memory Encryption (SME). 15507744ccdbSTom Lendacky 15517744ccdbSTom Lendacky If set to Y, then the encryption of system memory can be 15527744ccdbSTom Lendacky deactivated with the mem_encrypt=off command line option. 15537744ccdbSTom Lendacky 15547744ccdbSTom Lendacky If set to N, then the encryption of system memory can be 15557744ccdbSTom Lendacky activated with the mem_encrypt=on command line option. 15567744ccdbSTom Lendacky 1557506f1d07SSam Ravnborg# Common NUMA Features 1558506f1d07SSam Ravnborgconfig NUMA 1559e133f6eaSRandy Dunlap bool "NUMA Memory Allocation and Scheduler Support" 1560506f1d07SSam Ravnborg depends on SMP 1561b5660ba7SH. Peter Anvin depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1562b5660ba7SH. Peter Anvin default y if X86_BIGSMP 15637ecd19cfSKefeng Wang select USE_PERCPU_NUMA_NODE_ID 15640c436a58SSaurabh Sengar select OF_NUMA if OF 1565a7f7f624SMasahiro Yamada help 1566e133f6eaSRandy Dunlap Enable NUMA (Non-Uniform Memory Access) support. 1567fd51b2d7SKOSAKI Motohiro 1568506f1d07SSam Ravnborg The kernel will try to allocate memory used by a CPU on the 1569506f1d07SSam Ravnborg local memory controller of the CPU and add some more 1570506f1d07SSam Ravnborg NUMA awareness to the kernel. 1571506f1d07SSam Ravnborg 1572c280ea5eSIngo Molnar For 64-bit this is recommended if the system is Intel Core i7 1573fd51b2d7SKOSAKI Motohiro (or later), AMD Opteron, or EM64T NUMA. 1574fd51b2d7SKOSAKI Motohiro 1575b5660ba7SH. Peter Anvin For 32-bit this is only needed if you boot a 32-bit 15767cf6c945SDavid Rientjes kernel on a 64-bit NUMA platform. 1577fd51b2d7SKOSAKI Motohiro 1578fd51b2d7SKOSAKI Motohiro Otherwise, you should say N. 1579506f1d07SSam Ravnborg 1580eec1d4faSHans Rosenfeldconfig AMD_NUMA 15813c2362e6SHarvey Harrison def_bool y 15823c2362e6SHarvey Harrison prompt "Old style AMD Opteron NUMA detection" 15835da0ef9aSTejun Heo depends on X86_64 && NUMA && PCI 1584a7f7f624SMasahiro Yamada help 1585eec1d4faSHans Rosenfeld Enable AMD NUMA node topology detection. You should say Y here if 1586eec1d4faSHans Rosenfeld you have a multi processor AMD system. This uses an old method to 1587eec1d4faSHans Rosenfeld read the NUMA configuration directly from the builtin Northbridge 1588eec1d4faSHans Rosenfeld of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1589eec1d4faSHans Rosenfeld which also takes priority if both are compiled in. 1590506f1d07SSam Ravnborg 1591506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA 15923c2362e6SHarvey Harrison def_bool y 15933c2362e6SHarvey Harrison prompt "ACPI NUMA detection" 1594506f1d07SSam Ravnborg depends on X86_64 && NUMA && ACPI && PCI 1595506f1d07SSam Ravnborg select ACPI_NUMA 1596a7f7f624SMasahiro Yamada help 1597506f1d07SSam Ravnborg Enable ACPI SRAT based node topology detection. 1598506f1d07SSam Ravnborg 1599506f1d07SSam Ravnborgconfig NUMA_EMU 1600506f1d07SSam Ravnborg bool "NUMA emulation" 16011b7e03efSTejun Heo depends on NUMA 1602a7f7f624SMasahiro Yamada help 1603506f1d07SSam Ravnborg Enable NUMA emulation. A flat machine will be split 1604506f1d07SSam Ravnborg into virtual nodes when booted with "numa=fake=N", where N is the 1605506f1d07SSam Ravnborg number of nodes. This is only useful for debugging. 1606506f1d07SSam Ravnborg 1607506f1d07SSam Ravnborgconfig NODES_SHIFT 1608d25e26b6SLinus Torvalds int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 160951591e31SDavid Rientjes range 1 10 161051591e31SDavid Rientjes default "10" if MAXSMP 1611506f1d07SSam Ravnborg default "6" if X86_64 1612506f1d07SSam Ravnborg default "3" 1613a9ee6cf5SMike Rapoport depends on NUMA 1614a7f7f624SMasahiro Yamada help 16151184dc2fSMike Travis Specify the maximum number of NUMA Nodes available on the target 1616692105b8SMatt LaPlante system. Increases memory reserved to accommodate various tables. 1617506f1d07SSam Ravnborg 1618506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE 1619506f1d07SSam Ravnborg def_bool y 16203b16651fSTejun Heo depends on X86_32 && !NUMA 1621506f1d07SSam Ravnborg 1622506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE 1623506f1d07SSam Ravnborg def_bool y 16246ea30386SKees Cook depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1625506f1d07SSam Ravnborg select SPARSEMEM_STATIC if X86_32 1626506f1d07SSam Ravnborg select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1627506f1d07SSam Ravnborg 16283b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT 16296ad57f7fSMike Rapoport def_bool X86_64 || (NUMA && X86_32) 16303b16651fSTejun Heo 1631506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL 1632506f1d07SSam Ravnborg def_bool y 16334eda2bc3SDavid Hildenbrand depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE 1634506f1d07SSam Ravnborg 1635506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE 1636a0842b70SToshi Kani bool "Enable sysfs memory/probe interface" 16375c11f00bSDavid Hildenbrand depends on MEMORY_HOTPLUG 1638a0842b70SToshi Kani help 1639a0842b70SToshi Kani This option enables a sysfs memory/probe interface for testing. 1640cb1aaebeSMauro Carvalho Chehab See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1641a0842b70SToshi Kani If you are unsure how to answer this question, answer N. 1642506f1d07SSam Ravnborg 16433b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT 16443b16651fSTejun Heo def_bool y 16453b16651fSTejun Heo depends on X86_64 && PROC_KCORE 16463b16651fSTejun Heo 1647a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE 1648a29815a3SAvi Kivity hex 1649a29815a3SAvi Kivity default 0 if X86_32 1650a29815a3SAvi Kivity default 0xdead000000000000 if X86_64 1651a29815a3SAvi Kivity 16527a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE 16537a67832cSDan Williams bool 16547a67832cSDan Williams 1655ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY 16567a67832cSDan Williams tristate "Support non-standard NVDIMMs and ADR protected memory" 16579f53f9faSDan Williams depends on PHYS_ADDR_T_64BIT 16589f53f9faSDan Williams depends on BLK_DEV 16597a67832cSDan Williams select X86_PMEM_LEGACY_DEVICE 16607b27a862SDan Williams select NUMA_KEEP_MEMINFO if NUMA 16619f53f9faSDan Williams select LIBNVDIMM 1662ec776ef6SChristoph Hellwig help 1663ec776ef6SChristoph Hellwig Treat memory marked using the non-standard e820 type of 12 as used 1664ec776ef6SChristoph Hellwig by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1665ec776ef6SChristoph Hellwig The kernel will offer these regions to the 'pmem' driver so 1666ec776ef6SChristoph Hellwig they can be used for persistent storage. 1667ec776ef6SChristoph Hellwig 1668ec776ef6SChristoph Hellwig Say Y if unsure. 1669ec776ef6SChristoph Hellwig 1670506f1d07SSam Ravnborgconfig HIGHPTE 1671506f1d07SSam Ravnborg bool "Allocate 3rd-level pagetables from highmem" 16726fc108a0SJan Beulich depends on HIGHMEM 1673a7f7f624SMasahiro Yamada help 1674506f1d07SSam Ravnborg The VM uses one page table entry for each page of physical memory. 1675506f1d07SSam Ravnborg For systems with a lot of RAM, this can be wasteful of precious 1676506f1d07SSam Ravnborg low memory. Setting this option will put user-space page table 1677506f1d07SSam Ravnborg entries in high memory. 1678506f1d07SSam Ravnborg 16799f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION 16809f077871SJeremy Fitzhardinge bool "Check for low memory corruption" 1681a7f7f624SMasahiro Yamada help 16829f077871SJeremy Fitzhardinge Periodically check for memory corruption in low memory, which 16839f077871SJeremy Fitzhardinge is suspected to be caused by BIOS. Even when enabled in the 16849f077871SJeremy Fitzhardinge configuration, it is disabled at runtime. Enable it by 16859f077871SJeremy Fitzhardinge setting "memory_corruption_check=1" on the kernel command 16869f077871SJeremy Fitzhardinge line. By default it scans the low 64k of memory every 60 16879f077871SJeremy Fitzhardinge seconds; see the memory_corruption_check_size and 16889f077871SJeremy Fitzhardinge memory_corruption_check_period parameters in 16898c27ceffSMauro Carvalho Chehab Documentation/admin-guide/kernel-parameters.rst to adjust this. 16909f077871SJeremy Fitzhardinge 16919f077871SJeremy Fitzhardinge When enabled with the default parameters, this option has 16929f077871SJeremy Fitzhardinge almost no overhead, as it reserves a relatively small amount 16939f077871SJeremy Fitzhardinge of memory and scans it infrequently. It both detects corruption 16949f077871SJeremy Fitzhardinge and prevents it from affecting the running system. 16959f077871SJeremy Fitzhardinge 16969f077871SJeremy Fitzhardinge It is, however, intended as a diagnostic tool; if repeatable 16979f077871SJeremy Fitzhardinge BIOS-originated corruption always affects the same memory, 16989f077871SJeremy Fitzhardinge you can use memmap= to prevent the kernel from using that 16999f077871SJeremy Fitzhardinge memory. 17009f077871SJeremy Fitzhardinge 1701c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1702c885df50SJeremy Fitzhardinge bool "Set the default setting of memory_corruption_check" 1703c885df50SJeremy Fitzhardinge depends on X86_CHECK_BIOS_CORRUPTION 1704c885df50SJeremy Fitzhardinge default y 1705a7f7f624SMasahiro Yamada help 1706c885df50SJeremy Fitzhardinge Set whether the default state of memory_corruption_check is 1707c885df50SJeremy Fitzhardinge on or off. 1708c885df50SJeremy Fitzhardinge 1709506f1d07SSam Ravnborgconfig MATH_EMULATION 1710506f1d07SSam Ravnborg bool 1711a5b9e5a2SAndy Lutomirski depends on MODIFY_LDT_SYSCALL 171287d6021bSArnd Bergmann prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1713a7f7f624SMasahiro Yamada help 1714506f1d07SSam Ravnborg Linux can emulate a math coprocessor (used for floating point 1715506f1d07SSam Ravnborg operations) if you don't have one. 486DX and Pentium processors have 1716506f1d07SSam Ravnborg a math coprocessor built in, 486SX and 386 do not, unless you added 1717506f1d07SSam Ravnborg a 487DX or 387, respectively. (The messages during boot time can 1718506f1d07SSam Ravnborg give you some hints here ["man dmesg"].) Everyone needs either a 1719506f1d07SSam Ravnborg coprocessor or this emulation. 1720506f1d07SSam Ravnborg 1721506f1d07SSam Ravnborg If you don't have a math coprocessor, you need to say Y here; if you 1722506f1d07SSam Ravnborg say Y here even though you have a coprocessor, the coprocessor will 1723506f1d07SSam Ravnborg be used nevertheless. (This behavior can be changed with the kernel 1724506f1d07SSam Ravnborg command line option "no387", which comes handy if your coprocessor 1725506f1d07SSam Ravnborg is broken. Try "man bootparam" or see the documentation of your boot 1726506f1d07SSam Ravnborg loader (lilo or loadlin) about how to pass options to the kernel at 1727506f1d07SSam Ravnborg boot time.) This means that it is a good idea to say Y here if you 1728506f1d07SSam Ravnborg intend to use this kernel on different machines. 1729506f1d07SSam Ravnborg 1730506f1d07SSam Ravnborg More information about the internals of the Linux math coprocessor 1731506f1d07SSam Ravnborg emulation can be found in <file:arch/x86/math-emu/README>. 1732506f1d07SSam Ravnborg 1733506f1d07SSam Ravnborg If you are not sure, say Y; apart from resulting in a 66 KB bigger 1734506f1d07SSam Ravnborg kernel, it won't hurt. 1735506f1d07SSam Ravnborg 1736506f1d07SSam Ravnborgconfig MTRR 17376fc108a0SJan Beulich def_bool y 17386a108a14SDavid Rientjes prompt "MTRR (Memory Type Range Register) support" if EXPERT 1739a7f7f624SMasahiro Yamada help 1740506f1d07SSam Ravnborg On Intel P6 family processors (Pentium Pro, Pentium II and later) 1741506f1d07SSam Ravnborg the Memory Type Range Registers (MTRRs) may be used to control 1742506f1d07SSam Ravnborg processor access to memory ranges. This is most useful if you have 1743506f1d07SSam Ravnborg a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1744506f1d07SSam Ravnborg allows bus write transfers to be combined into a larger transfer 1745506f1d07SSam Ravnborg before bursting over the PCI/AGP bus. This can increase performance 1746506f1d07SSam Ravnborg of image write operations 2.5 times or more. Saying Y here creates a 1747506f1d07SSam Ravnborg /proc/mtrr file which may be used to manipulate your processor's 1748506f1d07SSam Ravnborg MTRRs. Typically the X server should use this. 1749506f1d07SSam Ravnborg 1750506f1d07SSam Ravnborg This code has a reasonably generic interface so that similar 1751506f1d07SSam Ravnborg control registers on other processors can be easily supported 1752506f1d07SSam Ravnborg as well: 1753506f1d07SSam Ravnborg 1754506f1d07SSam Ravnborg The Cyrix 6x86, 6x86MX and M II processors have Address Range 1755506f1d07SSam Ravnborg Registers (ARRs) which provide a similar functionality to MTRRs. For 1756506f1d07SSam Ravnborg these, the ARRs are used to emulate the MTRRs. 1757506f1d07SSam Ravnborg The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1758506f1d07SSam Ravnborg MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1759506f1d07SSam Ravnborg write-combining. All of these processors are supported by this code 1760506f1d07SSam Ravnborg and it makes sense to say Y here if you have one of them. 1761506f1d07SSam Ravnborg 1762506f1d07SSam Ravnborg Saying Y here also fixes a problem with buggy SMP BIOSes which only 1763506f1d07SSam Ravnborg set the MTRRs for the boot CPU and not for the secondary CPUs. This 1764506f1d07SSam Ravnborg can lead to all sorts of problems, so it's good to say Y here. 1765506f1d07SSam Ravnborg 1766506f1d07SSam Ravnborg You can safely say Y even if your machine doesn't have MTRRs, you'll 1767506f1d07SSam Ravnborg just add about 9 KB to your kernel. 1768506f1d07SSam Ravnborg 1769ff61f079SJonathan Corbet See <file:Documentation/arch/x86/mtrr.rst> for more information. 1770506f1d07SSam Ravnborg 177195ffa243SYinghai Luconfig MTRR_SANITIZER 17722ffb3501SYinghai Lu def_bool y 177395ffa243SYinghai Lu prompt "MTRR cleanup support" 177495ffa243SYinghai Lu depends on MTRR 1775a7f7f624SMasahiro Yamada help 1776aba3728cSThomas Gleixner Convert MTRR layout from continuous to discrete, so X drivers can 1777aba3728cSThomas Gleixner add writeback entries. 177895ffa243SYinghai Lu 1779aba3728cSThomas Gleixner Can be disabled with disable_mtrr_cleanup on the kernel command line. 1780692105b8SMatt LaPlante The largest mtrr entry size for a continuous block can be set with 1781aba3728cSThomas Gleixner mtrr_chunk_size. 178295ffa243SYinghai Lu 17832ffb3501SYinghai Lu If unsure, say Y. 178495ffa243SYinghai Lu 178595ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT 1786f5098d62SYinghai Lu int "MTRR cleanup enable value (0-1)" 1787f5098d62SYinghai Lu range 0 1 1788f5098d62SYinghai Lu default "0" 178995ffa243SYinghai Lu depends on MTRR_SANITIZER 1790a7f7f624SMasahiro Yamada help 1791f5098d62SYinghai Lu Enable mtrr cleanup default value 179295ffa243SYinghai Lu 179312031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 179412031a62SYinghai Lu int "MTRR cleanup spare reg num (0-7)" 179512031a62SYinghai Lu range 0 7 179612031a62SYinghai Lu default "1" 179712031a62SYinghai Lu depends on MTRR_SANITIZER 1798a7f7f624SMasahiro Yamada help 179912031a62SYinghai Lu mtrr cleanup spare entries default, it can be changed via 1800aba3728cSThomas Gleixner mtrr_spare_reg_nr=N on the kernel command line. 180112031a62SYinghai Lu 18022e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT 18036fc108a0SJan Beulich def_bool y 18046a108a14SDavid Rientjes prompt "x86 PAT support" if EXPERT 18052a8a2719SIngo Molnar depends on MTRR 1806a7f7f624SMasahiro Yamada help 18072e5d9c85Svenkatesh.pallipadi@intel.com Use PAT attributes to setup page level cache control. 1808042b78e4SVenki Pallipadi 18092e5d9c85Svenkatesh.pallipadi@intel.com PATs are the modern equivalents of MTRRs and are much more 18102e5d9c85Svenkatesh.pallipadi@intel.com flexible than MTRRs. 18112e5d9c85Svenkatesh.pallipadi@intel.com 18122e5d9c85Svenkatesh.pallipadi@intel.com Say N here if you see bootup problems (boot crash, boot hang, 1813042b78e4SVenki Pallipadi spontaneous reboots) or a non-working video driver. 18142e5d9c85Svenkatesh.pallipadi@intel.com 18152e5d9c85Svenkatesh.pallipadi@intel.com If unsure, say Y. 18162e5d9c85Svenkatesh.pallipadi@intel.com 181746cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED 181846cf98cdSVenkatesh Pallipadi def_bool y 181946cf98cdSVenkatesh Pallipadi depends on X86_PAT 182046cf98cdSVenkatesh Pallipadi 1821b971880fSBabu Mogerconfig X86_UMIP 1822796ebc81SRicardo Neri def_bool y 1823b971880fSBabu Moger prompt "User Mode Instruction Prevention" if EXPERT 1824a7f7f624SMasahiro Yamada help 1825b971880fSBabu Moger User Mode Instruction Prevention (UMIP) is a security feature in 1826b971880fSBabu Moger some x86 processors. If enabled, a general protection fault is 1827b971880fSBabu Moger issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1828b971880fSBabu Moger executed in user mode. These instructions unnecessarily expose 1829b971880fSBabu Moger information about the hardware state. 1830796ebc81SRicardo Neri 1831796ebc81SRicardo Neri The vast majority of applications do not use these instructions. 1832796ebc81SRicardo Neri For the very few that do, software emulation is provided in 1833796ebc81SRicardo Neri specific cases in protected and virtual-8086 modes. Emulated 1834796ebc81SRicardo Neri results are dummy. 1835aa35f896SRicardo Neri 1836156ff4a5SPeter Zijlstraconfig CC_HAS_IBT 1837156ff4a5SPeter Zijlstra # GCC >= 9 and binutils >= 2.29 1838156ff4a5SPeter Zijlstra # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 1839156ff4a5SPeter Zijlstra # Clang/LLVM >= 14 1840262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f 1841262448f3SNathan Chancellor # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 1842156ff4a5SPeter Zijlstra def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ 1843262448f3SNathan Chancellor (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ 1844156ff4a5SPeter Zijlstra $(as-instr,endbr64) 1845156ff4a5SPeter Zijlstra 184618e66b69SRick Edgecombeconfig X86_CET 184718e66b69SRick Edgecombe def_bool n 184818e66b69SRick Edgecombe help 184918e66b69SRick Edgecombe CET features configured (Shadow stack or IBT) 185018e66b69SRick Edgecombe 1851156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT 1852156ff4a5SPeter Zijlstra prompt "Indirect Branch Tracking" 18534fd5f70cSKees Cook def_bool y 185403f16cd0SJosh Poimboeuf depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL 1855f6a2c2b2SNathan Chancellor # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f 1856f6a2c2b2SNathan Chancellor depends on !LD_IS_LLD || LLD_VERSION >= 140000 185703f16cd0SJosh Poimboeuf select OBJTOOL 185818e66b69SRick Edgecombe select X86_CET 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 195218e66b69SRick Edgecombeconfig X86_USER_SHADOW_STACK 195318e66b69SRick Edgecombe bool "X86 userspace shadow stack" 195418e66b69SRick Edgecombe depends on AS_WRUSS 195518e66b69SRick Edgecombe depends on X86_64 195618e66b69SRick Edgecombe select ARCH_USES_HIGH_VMA_FLAGS 195718e66b69SRick Edgecombe select X86_CET 195818e66b69SRick Edgecombe help 195918e66b69SRick Edgecombe Shadow stack protection is a hardware feature that detects function 196018e66b69SRick Edgecombe return address corruption. This helps mitigate ROP attacks. 196118e66b69SRick Edgecombe Applications must be enabled to use it, and old userspace does not 196218e66b69SRick Edgecombe get protection "for free". 196318e66b69SRick Edgecombe 196418e66b69SRick Edgecombe CPUs supporting shadow stacks were first released in 2020. 196518e66b69SRick Edgecombe 196654acee60SDave Hansen See Documentation/arch/x86/shstk.rst for more information. 196718e66b69SRick Edgecombe 196818e66b69SRick Edgecombe If unsure, say N. 196918e66b69SRick Edgecombe 1970c33621b4SKai Huangconfig INTEL_TDX_HOST 1971c33621b4SKai Huang bool "Intel Trust Domain Extensions (TDX) host support" 1972c33621b4SKai Huang depends on CPU_SUP_INTEL 1973c33621b4SKai Huang depends on X86_64 1974c33621b4SKai Huang depends on KVM_INTEL 1975c33621b4SKai Huang help 1976c33621b4SKai Huang Intel Trust Domain Extensions (TDX) protects guest VMs from malicious 1977c33621b4SKai Huang host and certain physical attacks. This option enables necessary TDX 1978c33621b4SKai Huang support in the host kernel to run confidential VMs. 1979c33621b4SKai Huang 1980c33621b4SKai Huang If unsure, say N. 1981c33621b4SKai Huang 1982506f1d07SSam Ravnborgconfig EFI 19839ba16087SJan Beulich bool "EFI runtime service support" 19845b83683fSHuang, Ying depends on ACPI 1985f6ce5002SSergey Vlasov select UCS2_STRING 1986022ee6c5SArd Biesheuvel select EFI_RUNTIME_WRAPPERS 19871ff2fc02STom Lendacky select ARCH_USE_MEMREMAP_PROT 1988aba7e066SArd Biesheuvel select EFI_RUNTIME_MAP if KEXEC_CORE 1989a7f7f624SMasahiro Yamada help 19908b2cb7a8SHuang, Ying This enables the kernel to use EFI runtime services that are 1991506f1d07SSam Ravnborg available (such as the EFI variable services). 1992506f1d07SSam Ravnborg 19938b2cb7a8SHuang, Ying This option is only useful on systems that have EFI firmware. 19948b2cb7a8SHuang, Ying In addition, you should use the latest ELILO loader available 19958b2cb7a8SHuang, Ying at <http://elilo.sourceforge.net> in order to take advantage 19968b2cb7a8SHuang, Ying of EFI runtime services. However, even with this option, the 19978b2cb7a8SHuang, Ying resultant kernel should continue to boot on existing non-EFI 19988b2cb7a8SHuang, Ying platforms. 1999506f1d07SSam Ravnborg 2000291f3632SMatt Flemingconfig EFI_STUB 2001291f3632SMatt Fleming bool "EFI stub support" 2002c6dbd3e5SPeter Zijlstra depends on EFI 20037b2a583aSMatt Fleming select RELOCATABLE 2004a7f7f624SMasahiro Yamada help 2005291f3632SMatt Fleming This kernel feature allows a bzImage to be loaded directly 2006291f3632SMatt Fleming by EFI firmware without the use of a bootloader. 2007291f3632SMatt Fleming 20084f4cfa6cSMauro Carvalho Chehab See Documentation/admin-guide/efi-stub.rst for more information. 20090c759662SMatt Fleming 2010cc3fdda2SArd Biesheuvelconfig EFI_HANDOVER_PROTOCOL 2011cc3fdda2SArd Biesheuvel bool "EFI handover protocol (DEPRECATED)" 2012cc3fdda2SArd Biesheuvel depends on EFI_STUB 2013cc3fdda2SArd Biesheuvel default y 2014cc3fdda2SArd Biesheuvel help 2015cc3fdda2SArd Biesheuvel Select this in order to include support for the deprecated EFI 2016cc3fdda2SArd Biesheuvel handover protocol, which defines alternative entry points into the 2017cc3fdda2SArd Biesheuvel EFI stub. This is a practice that has no basis in the UEFI 2018cc3fdda2SArd Biesheuvel specification, and requires a priori knowledge on the part of the 2019cc3fdda2SArd Biesheuvel bootloader about Linux/x86 specific ways of passing the command line 2020cc3fdda2SArd Biesheuvel and initrd, and where in memory those assets may be loaded. 2021cc3fdda2SArd Biesheuvel 2022cc3fdda2SArd Biesheuvel If in doubt, say Y. Even though the corresponding support is not 2023cc3fdda2SArd Biesheuvel present in upstream GRUB or other bootloaders, most distros build 2024cc3fdda2SArd Biesheuvel GRUB with numerous downstream patches applied, and may rely on the 2025cc3fdda2SArd Biesheuvel handover protocol as as result. 2026cc3fdda2SArd Biesheuvel 20277d453eeeSMatt Flemingconfig EFI_MIXED 20287d453eeeSMatt Fleming bool "EFI mixed-mode support" 20297d453eeeSMatt Fleming depends on EFI_STUB && X86_64 2030a7f7f624SMasahiro Yamada help 20317d453eeeSMatt Fleming Enabling this feature allows a 64-bit kernel to be booted 20327d453eeeSMatt Fleming on a 32-bit firmware, provided that your CPU supports 64-bit 20337d453eeeSMatt Fleming mode. 20347d453eeeSMatt Fleming 20357d453eeeSMatt Fleming Note that it is not possible to boot a mixed-mode enabled 20367d453eeeSMatt Fleming kernel via the EFI boot stub - a bootloader that supports 20377d453eeeSMatt Fleming the EFI handover protocol must be used. 20387d453eeeSMatt Fleming 20397d453eeeSMatt Fleming If unsure, say N. 20407d453eeeSMatt Fleming 20414059ba65SArd Biesheuvelconfig EFI_FAKE_MEMMAP 20424059ba65SArd Biesheuvel bool "Enable EFI fake memory map" 20434059ba65SArd Biesheuvel depends on EFI 20444059ba65SArd Biesheuvel help 20454059ba65SArd Biesheuvel Saying Y here will enable "efi_fake_mem" boot option. By specifying 20464059ba65SArd Biesheuvel this parameter, you can add arbitrary attribute to specific memory 20474059ba65SArd Biesheuvel range by updating original (firmware provided) EFI memmap. This is 20484059ba65SArd Biesheuvel useful for debugging of EFI memmap related feature, e.g., Address 20494059ba65SArd Biesheuvel Range Mirroring feature. 20504059ba65SArd Biesheuvel 20514059ba65SArd Biesheuvelconfig EFI_MAX_FAKE_MEM 20524059ba65SArd Biesheuvel int "maximum allowable number of ranges in efi_fake_mem boot option" 20534059ba65SArd Biesheuvel depends on EFI_FAKE_MEMMAP 20544059ba65SArd Biesheuvel range 1 128 20554059ba65SArd Biesheuvel default 8 20564059ba65SArd Biesheuvel help 20574059ba65SArd Biesheuvel Maximum allowable number of ranges in efi_fake_mem boot option. 20584059ba65SArd Biesheuvel Ranges can be set up to this value using comma-separated list. 20594059ba65SArd Biesheuvel The default value is 8. 20604059ba65SArd Biesheuvel 20611fff234dSArd Biesheuvelconfig EFI_RUNTIME_MAP 20621fff234dSArd Biesheuvel bool "Export EFI runtime maps to sysfs" if EXPERT 20631fff234dSArd Biesheuvel depends on EFI 20641fff234dSArd Biesheuvel help 20651fff234dSArd Biesheuvel Export EFI runtime memory regions to /sys/firmware/efi/runtime-map. 20661fff234dSArd Biesheuvel That memory map is required by the 2nd kernel to set up EFI virtual 20671fff234dSArd Biesheuvel mappings after kexec, but can also be used for debugging purposes. 20681fff234dSArd Biesheuvel 20691fff234dSArd Biesheuvel See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map. 20701fff234dSArd Biesheuvel 20718636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz" 2072506f1d07SSam Ravnborg 20736af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC 20746af51380SEric DeVolder def_bool y 2075506f1d07SSam Ravnborg 20766af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_FILE 20776af51380SEric DeVolder def_bool X86_64 && CRYPTO && CRYPTO_SHA256 2078506f1d07SSam Ravnborg 20796af51380SEric DeVolderconfig ARCH_SELECTS_KEXEC_FILE 20806af51380SEric DeVolder def_bool y 20816af51380SEric DeVolder depends on KEXEC_FILE 2082b69a2afdSJonathan McDowell select HAVE_IMA_KEXEC if IMA 208374ca317cSVivek Goyal 2084e6265fe7SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_PURGATORY 2085b799a09fSAKASHI Takahiro def_bool KEXEC_FILE 2086b799a09fSAKASHI Takahiro 20876af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_SIG 20886af51380SEric DeVolder def_bool y 208999d5cadfSJiri Bohac 20906af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_SIG_FORCE 20916af51380SEric DeVolder def_bool y 209299d5cadfSJiri Bohac 20936af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG 20946af51380SEric DeVolder def_bool y 209599d5cadfSJiri Bohac 20966af51380SEric DeVolderconfig ARCH_SUPPORTS_KEXEC_JUMP 20976af51380SEric DeVolder def_bool y 20988e7d8381SVivek Goyal 20996af51380SEric DeVolderconfig ARCH_SUPPORTS_CRASH_DUMP 21006af51380SEric DeVolder def_bool X86_64 || (X86_32 && HIGHMEM) 21018e7d8381SVivek Goyal 2102ea53ad9cSEric DeVolderconfig ARCH_SUPPORTS_CRASH_HOTPLUG 2103ea53ad9cSEric DeVolder def_bool y 21043ab83521SHuang Ying 21059c08a2a1SBaoquan Heconfig ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 21069c08a2a1SBaoquan He def_bool CRASH_CORE 21079c08a2a1SBaoquan He 2108506f1d07SSam Ravnborgconfig PHYSICAL_START 21096a108a14SDavid Rientjes hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2110ceefccc9SH. Peter Anvin default "0x1000000" 2111a7f7f624SMasahiro Yamada help 2112506f1d07SSam Ravnborg This gives the physical address where the kernel is loaded. 2113506f1d07SSam Ravnborg 2114506f1d07SSam Ravnborg If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2115506f1d07SSam Ravnborg bzImage will decompress itself to above physical address and 2116506f1d07SSam Ravnborg run from there. Otherwise, bzImage will run from the address where 2117506f1d07SSam Ravnborg it has been loaded by the boot loader and will ignore above physical 2118506f1d07SSam Ravnborg address. 2119506f1d07SSam Ravnborg 2120506f1d07SSam Ravnborg In normal kdump cases one does not have to set/change this option 2121506f1d07SSam Ravnborg as now bzImage can be compiled as a completely relocatable image 2122506f1d07SSam Ravnborg (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2123506f1d07SSam Ravnborg address. This option is mainly useful for the folks who don't want 2124506f1d07SSam Ravnborg to use a bzImage for capturing the crash dump and want to use a 2125506f1d07SSam Ravnborg vmlinux instead. vmlinux is not relocatable hence a kernel needs 2126506f1d07SSam Ravnborg to be specifically compiled to run from a specific memory area 2127506f1d07SSam Ravnborg (normally a reserved region) and this option comes handy. 2128506f1d07SSam Ravnborg 2129ceefccc9SH. Peter Anvin So if you are using bzImage for capturing the crash dump, 2130ceefccc9SH. Peter Anvin leave the value here unchanged to 0x1000000 and set 2131ceefccc9SH. Peter Anvin CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2132ceefccc9SH. Peter Anvin for capturing the crash dump change this value to start of 2133ceefccc9SH. Peter Anvin the reserved region. In other words, it can be set based on 2134ceefccc9SH. Peter Anvin the "X" value as specified in the "crashkernel=YM@XM" 2135ceefccc9SH. Peter Anvin command line boot parameter passed to the panic-ed 2136330d4810SMauro Carvalho Chehab kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2137ceefccc9SH. Peter Anvin for more details about crash dumps. 2138506f1d07SSam Ravnborg 2139506f1d07SSam Ravnborg Usage of bzImage for capturing the crash dump is recommended as 2140506f1d07SSam Ravnborg one does not have to build two kernels. Same kernel can be used 2141506f1d07SSam Ravnborg as production kernel and capture kernel. Above option should have 2142506f1d07SSam Ravnborg gone away after relocatable bzImage support is introduced. But it 2143506f1d07SSam Ravnborg is present because there are users out there who continue to use 2144506f1d07SSam Ravnborg vmlinux for dump capture. This option should go away down the 2145506f1d07SSam Ravnborg line. 2146506f1d07SSam Ravnborg 2147506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2148506f1d07SSam Ravnborg 2149506f1d07SSam Ravnborgconfig RELOCATABLE 215026717808SH. Peter Anvin bool "Build a relocatable kernel" 215126717808SH. Peter Anvin default y 2152a7f7f624SMasahiro Yamada help 2153506f1d07SSam Ravnborg This builds a kernel image that retains relocation information 2154506f1d07SSam Ravnborg so it can be loaded someplace besides the default 1MB. 2155506f1d07SSam Ravnborg The relocations tend to make the kernel binary about 10% larger, 2156506f1d07SSam Ravnborg but are discarded at runtime. 2157506f1d07SSam Ravnborg 2158506f1d07SSam Ravnborg One use is for the kexec on panic case where the recovery kernel 2159506f1d07SSam Ravnborg must live at a different physical address than the primary 2160506f1d07SSam Ravnborg kernel. 2161506f1d07SSam Ravnborg 2162506f1d07SSam Ravnborg Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2163506f1d07SSam Ravnborg it has been loaded at and the compile time physical address 21648ab3820fSKees Cook (CONFIG_PHYSICAL_START) is used as the minimum location. 2165506f1d07SSam Ravnborg 21668ab3820fSKees Cookconfig RANDOMIZE_BASE 2167e8581e3dSBaoquan He bool "Randomize the address of the kernel image (KASLR)" 21688ab3820fSKees Cook depends on RELOCATABLE 21696807c846SIngo Molnar default y 2170a7f7f624SMasahiro Yamada help 2171e8581e3dSBaoquan He In support of Kernel Address Space Layout Randomization (KASLR), 2172e8581e3dSBaoquan He this randomizes the physical address at which the kernel image 2173e8581e3dSBaoquan He is decompressed and the virtual address where the kernel 2174e8581e3dSBaoquan He image is mapped, as a security feature that deters exploit 2175e8581e3dSBaoquan He attempts relying on knowledge of the location of kernel 2176e8581e3dSBaoquan He code internals. 2177e8581e3dSBaoquan He 2178ed9f007eSKees Cook On 64-bit, the kernel physical and virtual addresses are 2179ed9f007eSKees Cook randomized separately. The physical address will be anywhere 2180ed9f007eSKees Cook between 16MB and the top of physical memory (up to 64TB). The 2181ed9f007eSKees Cook virtual address will be randomized from 16MB up to 1GB (9 bits 2182ed9f007eSKees Cook of entropy). Note that this also reduces the memory space 2183ed9f007eSKees Cook available to kernel modules from 1.5GB to 1GB. 2184ed9f007eSKees Cook 2185ed9f007eSKees Cook On 32-bit, the kernel physical and virtual addresses are 2186ed9f007eSKees Cook randomized together. They will be randomized from 16MB up to 2187ed9f007eSKees Cook 512MB (8 bits of entropy). 21888ab3820fSKees Cook 2189a653f356SKees Cook Entropy is generated using the RDRAND instruction if it is 2190e8581e3dSBaoquan He supported. If RDTSC is supported, its value is mixed into 2191e8581e3dSBaoquan He the entropy pool as well. If neither RDRAND nor RDTSC are 2192ed9f007eSKees Cook supported, then entropy is read from the i8254 timer. The 2193ed9f007eSKees Cook usable entropy is limited by the kernel being built using 2194ed9f007eSKees Cook 2GB addressing, and that PHYSICAL_ALIGN must be at a 2195ed9f007eSKees Cook minimum of 2MB. As a result, only 10 bits of entropy are 2196ed9f007eSKees Cook theoretically possible, but the implementations are further 2197ed9f007eSKees Cook limited due to memory layouts. 2198e8581e3dSBaoquan He 21996807c846SIngo Molnar If unsure, say Y. 2200da2b6fb9SKees Cook 22018ab3820fSKees Cook# Relocation on x86 needs some additional build support 2202845adf72SH. Peter Anvinconfig X86_NEED_RELOCS 2203845adf72SH. Peter Anvin def_bool y 22048ab3820fSKees Cook depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2205845adf72SH. Peter Anvin 2206506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN 2207a0215061SKees Cook hex "Alignment value to which kernel should be aligned" 22088ab3820fSKees Cook default "0x200000" 2209a0215061SKees Cook range 0x2000 0x1000000 if X86_32 2210a0215061SKees Cook range 0x200000 0x1000000 if X86_64 2211a7f7f624SMasahiro Yamada help 2212506f1d07SSam Ravnborg This value puts the alignment restrictions on physical address 2213506f1d07SSam Ravnborg where kernel is loaded and run from. Kernel is compiled for an 2214506f1d07SSam Ravnborg address which meets above alignment restriction. 2215506f1d07SSam Ravnborg 2216506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2217506f1d07SSam Ravnborg CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2218506f1d07SSam Ravnborg address aligned to above value and run from there. 2219506f1d07SSam Ravnborg 2220506f1d07SSam Ravnborg If bootloader loads the kernel at a non-aligned address and 2221506f1d07SSam Ravnborg CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2222506f1d07SSam Ravnborg load address and decompress itself to the address it has been 2223506f1d07SSam Ravnborg compiled for and run from there. The address for which kernel is 2224506f1d07SSam Ravnborg compiled already meets above alignment restrictions. Hence the 2225506f1d07SSam Ravnborg end result is that kernel runs from a physical address meeting 2226506f1d07SSam Ravnborg above alignment restrictions. 2227506f1d07SSam Ravnborg 2228a0215061SKees Cook On 32-bit this value must be a multiple of 0x2000. On 64-bit 2229a0215061SKees Cook this value must be a multiple of 0x200000. 2230a0215061SKees Cook 2231506f1d07SSam Ravnborg Don't change this unless you know what you are doing. 2232506f1d07SSam Ravnborg 2233eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT 2234eedb92abSKirill A. Shutemov bool 2235a7f7f624SMasahiro Yamada help 2236eedb92abSKirill A. Shutemov This option makes base addresses of vmalloc and vmemmap as well as 2237eedb92abSKirill A. Shutemov __PAGE_OFFSET movable during boot. 2238eedb92abSKirill A. Shutemov 22390483e1faSThomas Garnierconfig RANDOMIZE_MEMORY 22400483e1faSThomas Garnier bool "Randomize the kernel memory sections" 22410483e1faSThomas Garnier depends on X86_64 22420483e1faSThomas Garnier depends on RANDOMIZE_BASE 2243eedb92abSKirill A. Shutemov select DYNAMIC_MEMORY_LAYOUT 22440483e1faSThomas Garnier default RANDOMIZE_BASE 2245a7f7f624SMasahiro Yamada help 22460483e1faSThomas Garnier Randomizes the base virtual address of kernel memory sections 22470483e1faSThomas Garnier (physical memory mapping, vmalloc & vmemmap). This security feature 22480483e1faSThomas Garnier makes exploits relying on predictable memory locations less reliable. 22490483e1faSThomas Garnier 22500483e1faSThomas Garnier The order of allocations remains unchanged. Entropy is generated in 22510483e1faSThomas Garnier the same way as RANDOMIZE_BASE. Current implementation in the optimal 22520483e1faSThomas Garnier configuration have in average 30,000 different possible virtual 22530483e1faSThomas Garnier addresses for each memory section. 22540483e1faSThomas Garnier 22556807c846SIngo Molnar If unsure, say Y. 22560483e1faSThomas Garnier 225790397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING 225890397a41SThomas Garnier hex "Physical memory mapping padding" if EXPERT 225990397a41SThomas Garnier depends on RANDOMIZE_MEMORY 226090397a41SThomas Garnier default "0xa" if MEMORY_HOTPLUG 226190397a41SThomas Garnier default "0x0" 226290397a41SThomas Garnier range 0x1 0x40 if MEMORY_HOTPLUG 226390397a41SThomas Garnier range 0x0 0x40 2264a7f7f624SMasahiro Yamada help 226590397a41SThomas Garnier Define the padding in terabytes added to the existing physical 226690397a41SThomas Garnier memory size during kernel memory randomization. It is useful 226790397a41SThomas Garnier for memory hotplug support but reduces the entropy available for 226890397a41SThomas Garnier address randomization. 226990397a41SThomas Garnier 227090397a41SThomas Garnier If unsure, leave at the default value. 227190397a41SThomas Garnier 22726449dcb0SKirill A. Shutemovconfig ADDRESS_MASKING 22736449dcb0SKirill A. Shutemov bool "Linear Address Masking support" 22746449dcb0SKirill A. Shutemov depends on X86_64 22756449dcb0SKirill A. Shutemov help 22766449dcb0SKirill A. Shutemov Linear Address Masking (LAM) modifies the checking that is applied 22776449dcb0SKirill A. Shutemov to 64-bit linear addresses, allowing software to use of the 22786449dcb0SKirill A. Shutemov untranslated address bits for metadata. 22796449dcb0SKirill A. Shutemov 22806449dcb0SKirill A. Shutemov The capability can be used for efficient address sanitizers (ASAN) 22816449dcb0SKirill A. Shutemov implementation and for optimizations in JITs. 22826449dcb0SKirill A. Shutemov 2283506f1d07SSam Ravnborgconfig HOTPLUG_CPU 2284bebd024eSThomas Gleixner def_bool y 228540b31360SStephen Rothwell depends on SMP 2286506f1d07SSam Ravnborg 2287506f1d07SSam Ravnborgconfig COMPAT_VDSO 2288b0b49f26SAndy Lutomirski def_bool n 2289b0b49f26SAndy Lutomirski prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2290953fee1dSIngo Molnar depends on COMPAT_32 2291a7f7f624SMasahiro Yamada help 2292b0b49f26SAndy Lutomirski Certain buggy versions of glibc will crash if they are 2293b0b49f26SAndy Lutomirski presented with a 32-bit vDSO that is not mapped at the address 2294b0b49f26SAndy Lutomirski indicated in its segment table. 2295e84446deSRandy Dunlap 2296b0b49f26SAndy Lutomirski The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2297b0b49f26SAndy Lutomirski and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2298b0b49f26SAndy Lutomirski 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2299b0b49f26SAndy Lutomirski the only released version with the bug, but OpenSUSE 9 2300b0b49f26SAndy Lutomirski contains a buggy "glibc 2.3.2". 2301506f1d07SSam Ravnborg 2302b0b49f26SAndy Lutomirski The symptom of the bug is that everything crashes on startup, saying: 2303b0b49f26SAndy Lutomirski dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2304b0b49f26SAndy Lutomirski 2305b0b49f26SAndy Lutomirski Saying Y here changes the default value of the vdso32 boot 2306b0b49f26SAndy Lutomirski option from 1 to 0, which turns off the 32-bit vDSO entirely. 2307b0b49f26SAndy Lutomirski This works around the glibc bug but hurts performance. 2308b0b49f26SAndy Lutomirski 2309b0b49f26SAndy Lutomirski If unsure, say N: if you are compiling your own kernel, you 2310b0b49f26SAndy Lutomirski are unlikely to be using a buggy version of glibc. 2311506f1d07SSam Ravnborg 23123dc33bd3SKees Cookchoice 23133dc33bd3SKees Cook prompt "vsyscall table for legacy applications" 23143dc33bd3SKees Cook depends on X86_64 2315625b7b7fSAndy Lutomirski default LEGACY_VSYSCALL_XONLY 23163dc33bd3SKees Cook help 23173dc33bd3SKees Cook Legacy user code that does not know how to find the vDSO expects 23183dc33bd3SKees Cook to be able to issue three syscalls by calling fixed addresses in 23193dc33bd3SKees Cook kernel space. Since this location is not randomized with ASLR, 23203dc33bd3SKees Cook it can be used to assist security vulnerability exploitation. 23213dc33bd3SKees Cook 23223dc33bd3SKees Cook This setting can be changed at boot time via the kernel command 2323bf00745eSAndy Lutomirski line parameter vsyscall=[emulate|xonly|none]. Emulate mode 2324bf00745eSAndy Lutomirski is deprecated and can only be enabled using the kernel command 2325bf00745eSAndy Lutomirski line. 23263dc33bd3SKees Cook 23273dc33bd3SKees Cook On a system with recent enough glibc (2.14 or newer) and no 23283dc33bd3SKees Cook static binaries, you can say None without a performance penalty 23293dc33bd3SKees Cook to improve security. 23303dc33bd3SKees Cook 2331bd49e16eSAndy Lutomirski If unsure, select "Emulate execution only". 23323dc33bd3SKees Cook 2333bd49e16eSAndy Lutomirski config LEGACY_VSYSCALL_XONLY 2334bd49e16eSAndy Lutomirski bool "Emulate execution only" 2335bd49e16eSAndy Lutomirski help 2336bd49e16eSAndy Lutomirski The kernel traps and emulates calls into the fixed vsyscall 2337bd49e16eSAndy Lutomirski address mapping and does not allow reads. This 2338bd49e16eSAndy Lutomirski configuration is recommended when userspace might use the 2339bd49e16eSAndy Lutomirski legacy vsyscall area but support for legacy binary 2340bd49e16eSAndy Lutomirski instrumentation of legacy code is not needed. It mitigates 2341bd49e16eSAndy Lutomirski certain uses of the vsyscall area as an ASLR-bypassing 2342bd49e16eSAndy Lutomirski buffer. 23433dc33bd3SKees Cook 23443dc33bd3SKees Cook config LEGACY_VSYSCALL_NONE 23453dc33bd3SKees Cook bool "None" 23463dc33bd3SKees Cook help 23473dc33bd3SKees Cook There will be no vsyscall mapping at all. This will 23483dc33bd3SKees Cook eliminate any risk of ASLR bypass due to the vsyscall 23493dc33bd3SKees Cook fixed address mapping. Attempts to use the vsyscalls 23503dc33bd3SKees Cook will be reported to dmesg, so that either old or 23513dc33bd3SKees Cook malicious userspace programs can be identified. 23523dc33bd3SKees Cook 23533dc33bd3SKees Cookendchoice 23543dc33bd3SKees Cook 2355516cbf37STim Birdconfig CMDLINE_BOOL 2356516cbf37STim Bird bool "Built-in kernel command line" 2357a7f7f624SMasahiro Yamada help 2358516cbf37STim Bird Allow for specifying boot arguments to the kernel at 2359516cbf37STim Bird build time. On some systems (e.g. embedded ones), it is 2360516cbf37STim Bird necessary or convenient to provide some or all of the 2361516cbf37STim Bird kernel boot arguments with the kernel itself (that is, 2362516cbf37STim Bird to not rely on the boot loader to provide them.) 2363516cbf37STim Bird 2364516cbf37STim Bird To compile command line arguments into the kernel, 2365516cbf37STim Bird set this option to 'Y', then fill in the 236669711ca1SSébastien Hinderer boot arguments in CONFIG_CMDLINE. 2367516cbf37STim Bird 2368516cbf37STim Bird Systems with fully functional boot loaders (i.e. non-embedded) 2369516cbf37STim Bird should leave this option set to 'N'. 2370516cbf37STim Bird 2371516cbf37STim Birdconfig CMDLINE 2372516cbf37STim Bird string "Built-in kernel command string" 2373516cbf37STim Bird depends on CMDLINE_BOOL 2374516cbf37STim Bird default "" 2375a7f7f624SMasahiro Yamada help 2376516cbf37STim Bird Enter arguments here that should be compiled into the kernel 2377516cbf37STim Bird image and used at boot time. If the boot loader provides a 2378516cbf37STim Bird command line at boot time, it is appended to this string to 2379516cbf37STim Bird form the full kernel command line, when the system boots. 2380516cbf37STim Bird 2381516cbf37STim Bird However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2382516cbf37STim Bird change this behavior. 2383516cbf37STim Bird 2384516cbf37STim Bird In most cases, the command line (whether built-in or provided 2385516cbf37STim Bird by the boot loader) should specify the device for the root 2386516cbf37STim Bird file system. 2387516cbf37STim Bird 2388516cbf37STim Birdconfig CMDLINE_OVERRIDE 2389516cbf37STim Bird bool "Built-in command line overrides boot loader arguments" 2390645e6466SAnders Roxell depends on CMDLINE_BOOL && CMDLINE != "" 2391a7f7f624SMasahiro Yamada help 2392516cbf37STim Bird Set this option to 'Y' to have the kernel ignore the boot loader 2393516cbf37STim Bird command line, and use ONLY the built-in command line. 2394516cbf37STim Bird 2395516cbf37STim Bird This is used to work around broken boot loaders. This should 2396516cbf37STim Bird be set to 'N' under normal conditions. 2397516cbf37STim Bird 2398a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL 2399a5b9e5a2SAndy Lutomirski bool "Enable the LDT (local descriptor table)" if EXPERT 2400a5b9e5a2SAndy Lutomirski default y 2401a7f7f624SMasahiro Yamada help 2402a5b9e5a2SAndy Lutomirski Linux can allow user programs to install a per-process x86 2403a5b9e5a2SAndy Lutomirski Local Descriptor Table (LDT) using the modify_ldt(2) system 2404a5b9e5a2SAndy Lutomirski call. This is required to run 16-bit or segmented code such as 2405a5b9e5a2SAndy Lutomirski DOSEMU or some Wine programs. It is also used by some very old 2406a5b9e5a2SAndy Lutomirski threading libraries. 2407a5b9e5a2SAndy Lutomirski 2408a5b9e5a2SAndy Lutomirski Enabling this feature adds a small amount of overhead to 2409a5b9e5a2SAndy Lutomirski context switches and increases the low-level kernel attack 2410a5b9e5a2SAndy Lutomirski surface. Disabling it removes the modify_ldt(2) system call. 2411a5b9e5a2SAndy Lutomirski 2412a5b9e5a2SAndy Lutomirski Saying 'N' here may make sense for embedded or server kernels. 2413a5b9e5a2SAndy Lutomirski 24143aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE 24153aac3ebeSThomas Gleixner bool "Enforce strict size checking for sigaltstack" 24163aac3ebeSThomas Gleixner depends on DYNAMIC_SIGFRAME 24173aac3ebeSThomas Gleixner help 24183aac3ebeSThomas Gleixner For historical reasons MINSIGSTKSZ is a constant which became 24193aac3ebeSThomas Gleixner already too small with AVX512 support. Add a mechanism to 24203aac3ebeSThomas Gleixner enforce strict checking of the sigaltstack size against the 24213aac3ebeSThomas Gleixner real size of the FPU frame. This option enables the check 24223aac3ebeSThomas Gleixner by default. It can also be controlled via the kernel command 24233aac3ebeSThomas Gleixner line option 'strict_sas_size' independent of this config 24243aac3ebeSThomas Gleixner switch. Enabling it might break existing applications which 24253aac3ebeSThomas Gleixner allocate a too small sigaltstack but 'work' because they 24263aac3ebeSThomas Gleixner never get a signal delivered. 24273aac3ebeSThomas Gleixner 24283aac3ebeSThomas Gleixner Say 'N' unless you want to really enforce this check. 24293aac3ebeSThomas Gleixner 2430b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig" 2431b700e7f0SSeth Jennings 2432506f1d07SSam Ravnborgendmenu 2433506f1d07SSam Ravnborg 2434f43b9876SPeter Zijlstraconfig CC_HAS_SLS 2435f43b9876SPeter Zijlstra def_bool $(cc-option,-mharden-sls=all) 2436f43b9876SPeter Zijlstra 2437f43b9876SPeter Zijlstraconfig CC_HAS_RETURN_THUNK 2438f43b9876SPeter Zijlstra def_bool $(cc-option,-mfunction-return=thunk-extern) 2439f43b9876SPeter Zijlstra 2440bea75b33SThomas Gleixnerconfig CC_HAS_ENTRY_PADDING 2441bea75b33SThomas Gleixner def_bool $(cc-option,-fpatchable-function-entry=16,16) 2442bea75b33SThomas Gleixner 2443bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_CFI 2444bea75b33SThomas Gleixner int 2445bea75b33SThomas Gleixner default 59 if FUNCTION_ALIGNMENT_64B 2446bea75b33SThomas Gleixner default 27 if FUNCTION_ALIGNMENT_32B 2447bea75b33SThomas Gleixner default 11 if FUNCTION_ALIGNMENT_16B 2448bea75b33SThomas Gleixner default 3 if FUNCTION_ALIGNMENT_8B 2449bea75b33SThomas Gleixner default 0 2450bea75b33SThomas Gleixner 2451bea75b33SThomas Gleixner# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG 2452bea75b33SThomas Gleixner# except Kconfig can't do arithmetic :/ 2453bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_BYTES 2454bea75b33SThomas Gleixner int 2455bea75b33SThomas Gleixner default FUNCTION_PADDING_CFI if CFI_CLANG 2456bea75b33SThomas Gleixner default FUNCTION_ALIGNMENT 2457bea75b33SThomas Gleixner 2458931ab636SPeter Zijlstraconfig CALL_PADDING 2459931ab636SPeter Zijlstra def_bool n 2460931ab636SPeter Zijlstra depends on CC_HAS_ENTRY_PADDING && OBJTOOL 2461931ab636SPeter Zijlstra select FUNCTION_ALIGNMENT_16B 2462931ab636SPeter Zijlstra 2463931ab636SPeter Zijlstraconfig FINEIBT 2464931ab636SPeter Zijlstra def_bool y 2465931ab636SPeter Zijlstra depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE 2466931ab636SPeter Zijlstra select CALL_PADDING 2467931ab636SPeter Zijlstra 24688f7c0d8bSThomas Gleixnerconfig HAVE_CALL_THUNKS 24698f7c0d8bSThomas Gleixner def_bool y 2470bea75b33SThomas Gleixner depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL 24718f7c0d8bSThomas Gleixner 24728f7c0d8bSThomas Gleixnerconfig CALL_THUNKS 24738f7c0d8bSThomas Gleixner def_bool n 2474931ab636SPeter Zijlstra select CALL_PADDING 24758f7c0d8bSThomas Gleixner 2476b341b20dSPeter Zijlstraconfig PREFIX_SYMBOLS 2477b341b20dSPeter Zijlstra def_bool y 2478931ab636SPeter Zijlstra depends on CALL_PADDING && !CFI_CLANG 2479b341b20dSPeter Zijlstra 2480f43b9876SPeter Zijlstramenuconfig SPECULATION_MITIGATIONS 2481f43b9876SPeter Zijlstra bool "Mitigations for speculative execution vulnerabilities" 2482f43b9876SPeter Zijlstra default y 2483f43b9876SPeter Zijlstra help 2484f43b9876SPeter Zijlstra Say Y here to enable options which enable mitigations for 2485f43b9876SPeter Zijlstra speculative execution hardware vulnerabilities. 2486f43b9876SPeter Zijlstra 2487f43b9876SPeter Zijlstra If you say N, all mitigations will be disabled. You really 2488f43b9876SPeter Zijlstra should know what you are doing to say so. 2489f43b9876SPeter Zijlstra 2490f43b9876SPeter Zijlstraif SPECULATION_MITIGATIONS 2491f43b9876SPeter Zijlstra 2492f43b9876SPeter Zijlstraconfig PAGE_TABLE_ISOLATION 2493f43b9876SPeter Zijlstra bool "Remove the kernel mapping in user mode" 2494f43b9876SPeter Zijlstra default y 2495f43b9876SPeter Zijlstra depends on (X86_64 || X86_PAE) 2496f43b9876SPeter Zijlstra help 2497f43b9876SPeter Zijlstra This feature reduces the number of hardware side channels by 2498f43b9876SPeter Zijlstra ensuring that the majority of kernel addresses are not mapped 2499f43b9876SPeter Zijlstra into userspace. 2500f43b9876SPeter Zijlstra 2501ff61f079SJonathan Corbet See Documentation/arch/x86/pti.rst for more details. 2502f43b9876SPeter Zijlstra 2503f43b9876SPeter Zijlstraconfig RETPOLINE 2504f43b9876SPeter Zijlstra bool "Avoid speculative indirect branches in kernel" 2505f43b9876SPeter Zijlstra select OBJTOOL if HAVE_OBJTOOL 2506f43b9876SPeter Zijlstra default y 2507f43b9876SPeter Zijlstra help 2508f43b9876SPeter Zijlstra Compile kernel with the retpoline compiler options to guard against 2509f43b9876SPeter Zijlstra kernel-to-user data leaks by avoiding speculative indirect 2510f43b9876SPeter Zijlstra branches. Requires a compiler with -mindirect-branch=thunk-extern 2511f43b9876SPeter Zijlstra support for full protection. The kernel may run slower. 2512f43b9876SPeter Zijlstra 2513f43b9876SPeter Zijlstraconfig RETHUNK 2514f43b9876SPeter Zijlstra bool "Enable return-thunks" 2515f43b9876SPeter Zijlstra depends on RETPOLINE && CC_HAS_RETURN_THUNK 2516f43b9876SPeter Zijlstra select OBJTOOL if HAVE_OBJTOOL 2517b648ab48SBen Hutchings default y if X86_64 2518f43b9876SPeter Zijlstra help 2519f43b9876SPeter Zijlstra Compile the kernel with the return-thunks compiler option to guard 2520f43b9876SPeter Zijlstra against kernel-to-user data leaks by avoiding return speculation. 2521f43b9876SPeter Zijlstra Requires a compiler with -mfunction-return=thunk-extern 2522f43b9876SPeter Zijlstra support for full protection. The kernel may run slower. 2523f43b9876SPeter Zijlstra 2524f43b9876SPeter Zijlstraconfig CPU_UNRET_ENTRY 2525f43b9876SPeter Zijlstra bool "Enable UNRET on kernel entry" 2526b648ab48SBen Hutchings depends on CPU_SUP_AMD && RETHUNK && X86_64 2527f43b9876SPeter Zijlstra default y 2528f43b9876SPeter Zijlstra help 2529f43b9876SPeter Zijlstra Compile the kernel with support for the retbleed=unret mitigation. 2530f43b9876SPeter Zijlstra 253180e4c1cdSThomas Gleixnerconfig CALL_DEPTH_TRACKING 253280e4c1cdSThomas Gleixner bool "Mitigate RSB underflow with call depth tracking" 253380e4c1cdSThomas Gleixner depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS 253480e4c1cdSThomas Gleixner select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 253580e4c1cdSThomas Gleixner select CALL_THUNKS 253680e4c1cdSThomas Gleixner default y 253780e4c1cdSThomas Gleixner help 253880e4c1cdSThomas Gleixner Compile the kernel with call depth tracking to mitigate the Intel 253980e4c1cdSThomas Gleixner SKL Return-Speculation-Buffer (RSB) underflow issue. The 254080e4c1cdSThomas Gleixner mitigation is off by default and needs to be enabled on the 254180e4c1cdSThomas Gleixner kernel command line via the retbleed=stuff option. For 254280e4c1cdSThomas Gleixner non-affected systems the overhead of this option is marginal as 254380e4c1cdSThomas Gleixner the call depth tracking is using run-time generated call thunks 254480e4c1cdSThomas Gleixner in a compiler generated padding area and call patching. This 254580e4c1cdSThomas Gleixner increases text size by ~5%. For non affected systems this space 254680e4c1cdSThomas Gleixner is unused. On affected SKL systems this results in a significant 254780e4c1cdSThomas Gleixner performance gain over the IBRS mitigation. 254880e4c1cdSThomas Gleixner 2549e81dc127SThomas Gleixnerconfig CALL_THUNKS_DEBUG 2550e81dc127SThomas Gleixner bool "Enable call thunks and call depth tracking debugging" 2551e81dc127SThomas Gleixner depends on CALL_DEPTH_TRACKING 2552e81dc127SThomas Gleixner select FUNCTION_ALIGNMENT_32B 2553e81dc127SThomas Gleixner default n 2554e81dc127SThomas Gleixner help 2555e81dc127SThomas Gleixner Enable call/ret counters for imbalance detection and build in 2556e81dc127SThomas Gleixner a noisy dmesg about callthunks generation and call patching for 2557e81dc127SThomas Gleixner trouble shooting. The debug prints need to be enabled on the 2558e81dc127SThomas Gleixner kernel command line with 'debug-callthunks'. 255954628de6SRandy Dunlap Only enable this when you are debugging call thunks as this 256054628de6SRandy Dunlap creates a noticeable runtime overhead. If unsure say N. 256180e4c1cdSThomas Gleixner 2562f43b9876SPeter Zijlstraconfig CPU_IBPB_ENTRY 2563f43b9876SPeter Zijlstra bool "Enable IBPB on kernel entry" 2564b648ab48SBen Hutchings depends on CPU_SUP_AMD && X86_64 2565f43b9876SPeter Zijlstra default y 2566f43b9876SPeter Zijlstra help 2567f43b9876SPeter Zijlstra Compile the kernel with support for the retbleed=ibpb mitigation. 2568f43b9876SPeter Zijlstra 2569f43b9876SPeter Zijlstraconfig CPU_IBRS_ENTRY 2570f43b9876SPeter Zijlstra bool "Enable IBRS on kernel entry" 2571b648ab48SBen Hutchings depends on CPU_SUP_INTEL && X86_64 2572f43b9876SPeter Zijlstra default y 2573f43b9876SPeter Zijlstra help 2574f43b9876SPeter Zijlstra Compile the kernel with support for the spectre_v2=ibrs mitigation. 2575f43b9876SPeter Zijlstra This mitigates both spectre_v2 and retbleed at great cost to 2576f43b9876SPeter Zijlstra performance. 2577f43b9876SPeter Zijlstra 2578fb3bd914SBorislav Petkov (AMD)config CPU_SRSO 2579fb3bd914SBorislav Petkov (AMD) bool "Mitigate speculative RAS overflow on AMD" 2580fb3bd914SBorislav Petkov (AMD) depends on CPU_SUP_AMD && X86_64 && RETHUNK 2581fb3bd914SBorislav Petkov (AMD) default y 2582fb3bd914SBorislav Petkov (AMD) help 2583fb3bd914SBorislav Petkov (AMD) Enable the SRSO mitigation needed on AMD Zen1-4 machines. 2584fb3bd914SBorislav Petkov (AMD) 2585f43b9876SPeter Zijlstraconfig SLS 2586f43b9876SPeter Zijlstra bool "Mitigate Straight-Line-Speculation" 2587f43b9876SPeter Zijlstra depends on CC_HAS_SLS && X86_64 2588f43b9876SPeter Zijlstra select OBJTOOL if HAVE_OBJTOOL 2589f43b9876SPeter Zijlstra default n 2590f43b9876SPeter Zijlstra help 2591f43b9876SPeter Zijlstra Compile the kernel with straight-line-speculation options to guard 2592f43b9876SPeter Zijlstra against straight line speculation. The kernel image might be slightly 2593f43b9876SPeter Zijlstra larger. 2594f43b9876SPeter Zijlstra 259553cf5797SDaniel Sneddonconfig GDS_FORCE_MITIGATION 259653cf5797SDaniel Sneddon bool "Force GDS Mitigation" 259753cf5797SDaniel Sneddon depends on CPU_SUP_INTEL 259853cf5797SDaniel Sneddon default n 259953cf5797SDaniel Sneddon help 260053cf5797SDaniel Sneddon Gather Data Sampling (GDS) is a hardware vulnerability which allows 260153cf5797SDaniel Sneddon unprivileged speculative access to data which was previously stored in 260253cf5797SDaniel Sneddon vector registers. 260353cf5797SDaniel Sneddon 260453cf5797SDaniel Sneddon This option is equivalent to setting gather_data_sampling=force on the 260553cf5797SDaniel Sneddon command line. The microcode mitigation is used if present, otherwise 260653cf5797SDaniel Sneddon AVX is disabled as a mitigation. On affected systems that are missing 260753cf5797SDaniel Sneddon the microcode any userspace code that unconditionally uses AVX will 260853cf5797SDaniel Sneddon break with this option set. 260953cf5797SDaniel Sneddon 261053cf5797SDaniel Sneddon Setting this option on systems not vulnerable to GDS has no effect. 261153cf5797SDaniel Sneddon 261253cf5797SDaniel Sneddon If in doubt, say N. 261353cf5797SDaniel Sneddon 2614f43b9876SPeter Zijlstraendif 2615f43b9876SPeter Zijlstra 26163072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES 26173072e413SMichal Hocko def_bool y 26185c11f00bSDavid Hildenbrand depends on ARCH_ENABLE_MEMORY_HOTPLUG 26193072e413SMichal Hocko 2620da85f865SBjorn Helgaasmenu "Power management and ACPI options" 2621e279b6c1SSam Ravnborg 2622e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER 26233c2362e6SHarvey Harrison def_bool y 262444556530SZhimin Gu depends on HIBERNATION 2625e279b6c1SSam Ravnborg 2626e279b6c1SSam Ravnborgsource "kernel/power/Kconfig" 2627e279b6c1SSam Ravnborg 2628e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig" 2629e279b6c1SSam Ravnborg 2630a6b68076SAndi Kleenconfig X86_APM_BOOT 26316fc108a0SJan Beulich def_bool y 2632282e5aabSPaul Bolle depends on APM 2633a6b68076SAndi Kleen 2634e279b6c1SSam Ravnborgmenuconfig APM 2635e279b6c1SSam Ravnborg tristate "APM (Advanced Power Management) BIOS support" 2636efefa6f6SIngo Molnar depends on X86_32 && PM_SLEEP 2637a7f7f624SMasahiro Yamada help 2638e279b6c1SSam Ravnborg APM is a BIOS specification for saving power using several different 2639e279b6c1SSam Ravnborg techniques. This is mostly useful for battery powered laptops with 2640e279b6c1SSam Ravnborg APM compliant BIOSes. If you say Y here, the system time will be 2641e279b6c1SSam Ravnborg reset after a RESUME operation, the /proc/apm device will provide 2642e279b6c1SSam Ravnborg battery status information, and user-space programs will receive 2643e279b6c1SSam Ravnborg notification of APM "events" (e.g. battery status change). 2644e279b6c1SSam Ravnborg 2645e279b6c1SSam Ravnborg If you select "Y" here, you can disable actual use of the APM 2646e279b6c1SSam Ravnborg BIOS by passing the "apm=off" option to the kernel at boot time. 2647e279b6c1SSam Ravnborg 2648e279b6c1SSam Ravnborg Note that the APM support is almost completely disabled for 2649e279b6c1SSam Ravnborg machines with more than one CPU. 2650e279b6c1SSam Ravnborg 2651e279b6c1SSam Ravnborg In order to use APM, you will need supporting software. For location 2652151f4e2bSMauro Carvalho Chehab and more information, read <file:Documentation/power/apm-acpi.rst> 26532dc98fd3SMichael Witten and the Battery Powered Linux mini-HOWTO, available from 2654e279b6c1SSam Ravnborg <http://www.tldp.org/docs.html#howto>. 2655e279b6c1SSam Ravnborg 2656e279b6c1SSam Ravnborg This driver does not spin down disk drives (see the hdparm(8) 2657e279b6c1SSam Ravnborg manpage ("man 8 hdparm") for that), and it doesn't turn off 2658e279b6c1SSam Ravnborg VESA-compliant "green" monitors. 2659e279b6c1SSam Ravnborg 2660e279b6c1SSam Ravnborg This driver does not support the TI 4000M TravelMate and the ACER 2661e279b6c1SSam Ravnborg 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2662e279b6c1SSam Ravnborg desktop machines also don't have compliant BIOSes, and this driver 2663e279b6c1SSam Ravnborg may cause those machines to panic during the boot phase. 2664e279b6c1SSam Ravnborg 2665e279b6c1SSam Ravnborg Generally, if you don't have a battery in your machine, there isn't 2666e279b6c1SSam Ravnborg much point in using this driver and you should say N. If you get 2667e279b6c1SSam Ravnborg random kernel OOPSes or reboots that don't seem to be related to 2668e279b6c1SSam Ravnborg anything, try disabling/enabling this option (or disabling/enabling 2669e279b6c1SSam Ravnborg APM in your BIOS). 2670e279b6c1SSam Ravnborg 2671e279b6c1SSam Ravnborg Some other things you should try when experiencing seemingly random, 2672e279b6c1SSam Ravnborg "weird" problems: 2673e279b6c1SSam Ravnborg 2674e279b6c1SSam Ravnborg 1) make sure that you have enough swap space and that it is 2675e279b6c1SSam Ravnborg enabled. 26767987448fSStephen Kitt 2) pass the "idle=poll" option to the kernel 2677e279b6c1SSam Ravnborg 3) switch on floating point emulation in the kernel and pass 2678e279b6c1SSam Ravnborg the "no387" option to the kernel 2679e279b6c1SSam Ravnborg 4) pass the "floppy=nodma" option to the kernel 2680e279b6c1SSam Ravnborg 5) pass the "mem=4M" option to the kernel (thereby disabling 2681e279b6c1SSam Ravnborg all but the first 4 MB of RAM) 2682e279b6c1SSam Ravnborg 6) make sure that the CPU is not over clocked. 2683e279b6c1SSam Ravnborg 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2684e279b6c1SSam Ravnborg 8) disable the cache from your BIOS settings 2685e279b6c1SSam Ravnborg 9) install a fan for the video card or exchange video RAM 2686e279b6c1SSam Ravnborg 10) install a better fan for the CPU 2687e279b6c1SSam Ravnborg 11) exchange RAM chips 2688e279b6c1SSam Ravnborg 12) exchange the motherboard. 2689e279b6c1SSam Ravnborg 2690e279b6c1SSam Ravnborg To compile this driver as a module, choose M here: the 2691e279b6c1SSam Ravnborg module will be called apm. 2692e279b6c1SSam Ravnborg 2693e279b6c1SSam Ravnborgif APM 2694e279b6c1SSam Ravnborg 2695e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND 2696e279b6c1SSam Ravnborg bool "Ignore USER SUSPEND" 2697a7f7f624SMasahiro Yamada help 2698e279b6c1SSam Ravnborg This option will ignore USER SUSPEND requests. On machines with a 2699e279b6c1SSam Ravnborg compliant APM BIOS, you want to say N. However, on the NEC Versa M 2700e279b6c1SSam Ravnborg series notebooks, it is necessary to say Y because of a BIOS bug. 2701e279b6c1SSam Ravnborg 2702e279b6c1SSam Ravnborgconfig APM_DO_ENABLE 2703e279b6c1SSam Ravnborg bool "Enable PM at boot time" 2704a7f7f624SMasahiro Yamada help 2705e279b6c1SSam Ravnborg Enable APM features at boot time. From page 36 of the APM BIOS 2706e279b6c1SSam Ravnborg specification: "When disabled, the APM BIOS does not automatically 2707e279b6c1SSam Ravnborg power manage devices, enter the Standby State, enter the Suspend 2708e279b6c1SSam Ravnborg State, or take power saving steps in response to CPU Idle calls." 2709e279b6c1SSam Ravnborg This driver will make CPU Idle calls when Linux is idle (unless this 2710e279b6c1SSam Ravnborg feature is turned off -- see "Do CPU IDLE calls", below). This 2711e279b6c1SSam Ravnborg should always save battery power, but more complicated APM features 2712e279b6c1SSam Ravnborg will be dependent on your BIOS implementation. You may need to turn 2713e279b6c1SSam Ravnborg this option off if your computer hangs at boot time when using APM 2714e279b6c1SSam Ravnborg support, or if it beeps continuously instead of suspending. Turn 2715e279b6c1SSam Ravnborg this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2716e279b6c1SSam Ravnborg T400CDT. This is off by default since most machines do fine without 2717e279b6c1SSam Ravnborg this feature. 2718e279b6c1SSam Ravnborg 2719e279b6c1SSam Ravnborgconfig APM_CPU_IDLE 2720dd8af076SLen Brown depends on CPU_IDLE 2721e279b6c1SSam Ravnborg bool "Make CPU Idle calls when idle" 2722a7f7f624SMasahiro Yamada help 2723e279b6c1SSam Ravnborg Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2724e279b6c1SSam Ravnborg On some machines, this can activate improved power savings, such as 2725e279b6c1SSam Ravnborg a slowed CPU clock rate, when the machine is idle. These idle calls 2726e279b6c1SSam Ravnborg are made after the idle loop has run for some length of time (e.g., 2727e279b6c1SSam Ravnborg 333 mS). On some machines, this will cause a hang at boot time or 2728e279b6c1SSam Ravnborg whenever the CPU becomes idle. (On machines with more than one CPU, 2729e279b6c1SSam Ravnborg this option does nothing.) 2730e279b6c1SSam Ravnborg 2731e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK 2732e279b6c1SSam Ravnborg bool "Enable console blanking using APM" 2733a7f7f624SMasahiro Yamada help 2734e279b6c1SSam Ravnborg Enable console blanking using the APM. Some laptops can use this to 2735e279b6c1SSam Ravnborg turn off the LCD backlight when the screen blanker of the Linux 2736e279b6c1SSam Ravnborg virtual console blanks the screen. Note that this is only used by 2737e279b6c1SSam Ravnborg the virtual console screen blanker, and won't turn off the backlight 2738e279b6c1SSam Ravnborg when using the X Window system. This also doesn't have anything to 2739e279b6c1SSam Ravnborg do with your VESA-compliant power-saving monitor. Further, this 2740e279b6c1SSam Ravnborg option doesn't work for all laptops -- it might not turn off your 2741e279b6c1SSam Ravnborg backlight at all, or it might print a lot of errors to the console, 2742e279b6c1SSam Ravnborg especially if you are using gpm. 2743e279b6c1SSam Ravnborg 2744e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS 2745e279b6c1SSam Ravnborg bool "Allow interrupts during APM BIOS calls" 2746a7f7f624SMasahiro Yamada help 2747e279b6c1SSam Ravnborg Normally we disable external interrupts while we are making calls to 2748e279b6c1SSam Ravnborg the APM BIOS as a measure to lessen the effects of a badly behaving 2749e279b6c1SSam Ravnborg BIOS implementation. The BIOS should reenable interrupts if it 2750e279b6c1SSam Ravnborg needs to. Unfortunately, some BIOSes do not -- especially those in 2751e279b6c1SSam Ravnborg many of the newer IBM Thinkpads. If you experience hangs when you 2752e279b6c1SSam Ravnborg suspend, try setting this to Y. Otherwise, say N. 2753e279b6c1SSam Ravnborg 2754e279b6c1SSam Ravnborgendif # APM 2755e279b6c1SSam Ravnborg 2756bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig" 2757e279b6c1SSam Ravnborg 2758e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig" 2759e279b6c1SSam Ravnborg 276027471fdbSAndy Henroidsource "drivers/idle/Kconfig" 276127471fdbSAndy Henroid 2762e279b6c1SSam Ravnborgendmenu 2763e279b6c1SSam Ravnborg 2764e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)" 2765e279b6c1SSam Ravnborg 2766e279b6c1SSam Ravnborgchoice 2767e279b6c1SSam Ravnborg prompt "PCI access mode" 2768efefa6f6SIngo Molnar depends on X86_32 && PCI 2769e279b6c1SSam Ravnborg default PCI_GOANY 2770a7f7f624SMasahiro Yamada help 2771e279b6c1SSam Ravnborg On PCI systems, the BIOS can be used to detect the PCI devices and 2772e279b6c1SSam Ravnborg determine their configuration. However, some old PCI motherboards 2773e279b6c1SSam Ravnborg have BIOS bugs and may crash if this is done. Also, some embedded 2774e279b6c1SSam Ravnborg PCI-based systems don't have any BIOS at all. Linux can also try to 2775e279b6c1SSam Ravnborg detect the PCI hardware directly without using the BIOS. 2776e279b6c1SSam Ravnborg 2777e279b6c1SSam Ravnborg With this option, you can specify how Linux should detect the 2778e279b6c1SSam Ravnborg PCI devices. If you choose "BIOS", the BIOS will be used, 2779e279b6c1SSam Ravnborg if you choose "Direct", the BIOS won't be used, and if you 2780e279b6c1SSam Ravnborg choose "MMConfig", then PCI Express MMCONFIG will be used. 2781e279b6c1SSam Ravnborg If you choose "Any", the kernel will try MMCONFIG, then the 2782e279b6c1SSam Ravnborg direct access method and falls back to the BIOS if that doesn't 2783e279b6c1SSam Ravnborg work. If unsure, go with the default, which is "Any". 2784e279b6c1SSam Ravnborg 2785e279b6c1SSam Ravnborgconfig PCI_GOBIOS 2786e279b6c1SSam Ravnborg bool "BIOS" 2787e279b6c1SSam Ravnborg 2788e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG 2789e279b6c1SSam Ravnborg bool "MMConfig" 2790e279b6c1SSam Ravnborg 2791e279b6c1SSam Ravnborgconfig PCI_GODIRECT 2792e279b6c1SSam Ravnborg bool "Direct" 2793e279b6c1SSam Ravnborg 27943ef0e1f8SAndres Salomonconfig PCI_GOOLPC 279576fb6570SDaniel Drake bool "OLPC XO-1" 27963ef0e1f8SAndres Salomon depends on OLPC 27973ef0e1f8SAndres Salomon 27982bdd1b03SAndres Salomonconfig PCI_GOANY 27992bdd1b03SAndres Salomon bool "Any" 28002bdd1b03SAndres Salomon 2801e279b6c1SSam Ravnborgendchoice 2802e279b6c1SSam Ravnborg 2803e279b6c1SSam Ravnborgconfig PCI_BIOS 28043c2362e6SHarvey Harrison def_bool y 2805efefa6f6SIngo Molnar depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2806e279b6c1SSam Ravnborg 2807e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2808e279b6c1SSam Ravnborgconfig PCI_DIRECT 28093c2362e6SHarvey Harrison def_bool y 28100aba496fSShaohua Li depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2811e279b6c1SSam Ravnborg 2812e279b6c1SSam Ravnborgconfig PCI_MMCONFIG 2813b45c9f36SJan Kiszka bool "Support mmconfig PCI config space access" if X86_64 2814b45c9f36SJan Kiszka default y 28154590d98fSAndy Shevchenko depends on PCI && (ACPI || JAILHOUSE_GUEST) 2816b45c9f36SJan Kiszka depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2817e279b6c1SSam Ravnborg 28183ef0e1f8SAndres Salomonconfig PCI_OLPC 28192bdd1b03SAndres Salomon def_bool y 28202bdd1b03SAndres Salomon depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 28213ef0e1f8SAndres Salomon 2822b5401a96SAlex Nixonconfig PCI_XEN 2823b5401a96SAlex Nixon def_bool y 2824b5401a96SAlex Nixon depends on PCI && XEN 2825b5401a96SAlex Nixon 28268364e1f8SJan Kiszkaconfig MMCONF_FAM10H 28278364e1f8SJan Kiszka def_bool y 28288364e1f8SJan Kiszka depends on X86_64 && PCI_MMCONFIG && ACPI 2829e279b6c1SSam Ravnborg 28303f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK 28316a108a14SDavid Rientjes bool "Read CNB20LE Host Bridge Windows" if EXPERT 28326ea30386SKees Cook depends on PCI 28333f6ea84aSIra W. Snyder help 28343f6ea84aSIra W. Snyder Read the PCI windows out of the CNB20LE host bridge. This allows 28353f6ea84aSIra W. Snyder PCI hotplug to work on systems with the CNB20LE chipset which do 28363f6ea84aSIra W. Snyder not have ACPI. 28373f6ea84aSIra W. Snyder 283864a5fed6SBjorn Helgaas There's no public spec for this chipset, and this functionality 283964a5fed6SBjorn Helgaas is known to be incomplete. 284064a5fed6SBjorn Helgaas 284164a5fed6SBjorn Helgaas You should say N unless you know you need this. 284264a5fed6SBjorn Helgaas 28433a495511SWilliam Breathitt Grayconfig ISA_BUS 284417a2a129SWilliam Breathitt Gray bool "ISA bus support on modern systems" if EXPERT 28453a495511SWilliam Breathitt Gray help 284617a2a129SWilliam Breathitt Gray Expose ISA bus device drivers and options available for selection and 284717a2a129SWilliam Breathitt Gray configuration. Enable this option if your target machine has an ISA 284817a2a129SWilliam Breathitt Gray bus. ISA is an older system, displaced by PCI and newer bus 284917a2a129SWilliam Breathitt Gray architectures -- if your target machine is modern, it probably does 285017a2a129SWilliam Breathitt Gray not have an ISA bus. 28513a495511SWilliam Breathitt Gray 28523a495511SWilliam Breathitt Gray If unsure, say N. 28533a495511SWilliam Breathitt Gray 28541c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA. 2855e279b6c1SSam Ravnborgconfig ISA_DMA_API 28561c00f016SDavid Rientjes bool "ISA-style DMA support" if (X86_64 && EXPERT) 28571c00f016SDavid Rientjes default y 28581c00f016SDavid Rientjes help 28591c00f016SDavid Rientjes Enables ISA-style DMA support for devices requiring such controllers. 28601c00f016SDavid Rientjes If unsure, say Y. 2861e279b6c1SSam Ravnborg 286251e68d05SLinus Torvaldsif X86_32 286351e68d05SLinus Torvalds 2864e279b6c1SSam Ravnborgconfig ISA 2865e279b6c1SSam Ravnborg bool "ISA support" 2866a7f7f624SMasahiro Yamada help 2867e279b6c1SSam Ravnborg Find out whether you have ISA slots on your motherboard. ISA is the 2868e279b6c1SSam Ravnborg name of a bus system, i.e. the way the CPU talks to the other stuff 2869e279b6c1SSam Ravnborg inside your box. Other bus systems are PCI, EISA, MicroChannel 2870e279b6c1SSam Ravnborg (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2871e279b6c1SSam Ravnborg newer boards don't support it. If you have ISA, say Y, otherwise N. 2872e279b6c1SSam Ravnborg 2873e279b6c1SSam Ravnborgconfig SCx200 2874e279b6c1SSam Ravnborg tristate "NatSemi SCx200 support" 2875a7f7f624SMasahiro Yamada help 2876e279b6c1SSam Ravnborg This provides basic support for National Semiconductor's 2877e279b6c1SSam Ravnborg (now AMD's) Geode processors. The driver probes for the 2878e279b6c1SSam Ravnborg PCI-IDs of several on-chip devices, so its a good dependency 2879e279b6c1SSam Ravnborg for other scx200_* drivers. 2880e279b6c1SSam Ravnborg 2881e279b6c1SSam Ravnborg If compiled as a module, the driver is named scx200. 2882e279b6c1SSam Ravnborg 2883e279b6c1SSam Ravnborgconfig SCx200HR_TIMER 2884e279b6c1SSam Ravnborg tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2885592913ecSJohn Stultz depends on SCx200 2886e279b6c1SSam Ravnborg default y 2887a7f7f624SMasahiro Yamada help 2888e279b6c1SSam Ravnborg This driver provides a clocksource built upon the on-chip 2889e279b6c1SSam Ravnborg 27MHz high-resolution timer. Its also a workaround for 2890e279b6c1SSam Ravnborg NSC Geode SC-1100's buggy TSC, which loses time when the 2891e279b6c1SSam Ravnborg processor goes idle (as is done by the scheduler). The 2892e279b6c1SSam Ravnborg other workaround is idle=poll boot option. 2893e279b6c1SSam Ravnborg 28943ef0e1f8SAndres Salomonconfig OLPC 28953ef0e1f8SAndres Salomon bool "One Laptop Per Child support" 289654008979SThomas Gleixner depends on !X86_PAE 28973c554946SAndres Salomon select GPIOLIB 2898dc3119e7SThomas Gleixner select OF 289945bb1674SDaniel Drake select OF_PROMTREE 2900b4e51854SGrant Likely select IRQ_DOMAIN 29010c3d931bSLubomir Rintel select OLPC_EC 2902a7f7f624SMasahiro Yamada help 29033ef0e1f8SAndres Salomon Add support for detecting the unique features of the OLPC 29043ef0e1f8SAndres Salomon XO hardware. 29053ef0e1f8SAndres Salomon 2906a3128588SDaniel Drakeconfig OLPC_XO1_PM 2907a3128588SDaniel Drake bool "OLPC XO-1 Power Management" 2908fa112cf1SBorislav Petkov depends on OLPC && MFD_CS5535=y && PM_SLEEP 2909a7f7f624SMasahiro Yamada help 291097c4cb71SDaniel Drake Add support for poweroff and suspend of the OLPC XO-1 laptop. 2911bf1ebf00SDaniel Drake 2912cfee9597SDaniel Drakeconfig OLPC_XO1_RTC 2913cfee9597SDaniel Drake bool "OLPC XO-1 Real Time Clock" 2914cfee9597SDaniel Drake depends on OLPC_XO1_PM && RTC_DRV_CMOS 2915a7f7f624SMasahiro Yamada help 2916cfee9597SDaniel Drake Add support for the XO-1 real time clock, which can be used as a 2917cfee9597SDaniel Drake programmable wakeup source. 2918cfee9597SDaniel Drake 29197feda8e9SDaniel Drakeconfig OLPC_XO1_SCI 29207feda8e9SDaniel Drake bool "OLPC XO-1 SCI extras" 292192e830f2SArnd Bergmann depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2922ed8e47feSRandy Dunlap depends on INPUT=y 2923d8d01a63SDaniel Drake select POWER_SUPPLY 2924a7f7f624SMasahiro Yamada help 29257feda8e9SDaniel Drake Add support for SCI-based features of the OLPC XO-1 laptop: 29267bc74b3dSDaniel Drake - EC-driven system wakeups 29277feda8e9SDaniel Drake - Power button 29287bc74b3dSDaniel Drake - Ebook switch 29292cf2baeaSDaniel Drake - Lid switch 2930e1040ac6SDaniel Drake - AC adapter status updates 2931e1040ac6SDaniel Drake - Battery status updates 29327feda8e9SDaniel Drake 2933a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI 2934a0f30f59SDaniel Drake bool "OLPC XO-1.5 SCI extras" 2935d8d01a63SDaniel Drake depends on OLPC && ACPI 2936d8d01a63SDaniel Drake select POWER_SUPPLY 2937a7f7f624SMasahiro Yamada help 2938a0f30f59SDaniel Drake Add support for SCI-based features of the OLPC XO-1.5 laptop: 2939a0f30f59SDaniel Drake - EC-driven system wakeups 2940a0f30f59SDaniel Drake - AC adapter status updates 2941a0f30f59SDaniel Drake - Battery status updates 2942e279b6c1SSam Ravnborg 2943d4f3e350SEd Wildgooseconfig ALIX 2944d4f3e350SEd Wildgoose bool "PCEngines ALIX System Support (LED setup)" 2945d4f3e350SEd Wildgoose select GPIOLIB 2946a7f7f624SMasahiro Yamada help 2947d4f3e350SEd Wildgoose This option enables system support for the PCEngines ALIX. 2948d4f3e350SEd Wildgoose At present this just sets up LEDs for GPIO control on 2949d4f3e350SEd Wildgoose ALIX2/3/6 boards. However, other system specific setup should 2950d4f3e350SEd Wildgoose get added here. 2951d4f3e350SEd Wildgoose 2952d4f3e350SEd Wildgoose Note: You must still enable the drivers for GPIO and LED support 2953d4f3e350SEd Wildgoose (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2954d4f3e350SEd Wildgoose 2955d4f3e350SEd Wildgoose Note: You have to set alix.force=1 for boards with Award BIOS. 2956d4f3e350SEd Wildgoose 2957da4e3302SPhilip Prindevilleconfig NET5501 2958da4e3302SPhilip Prindeville bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2959da4e3302SPhilip Prindeville select GPIOLIB 2960a7f7f624SMasahiro Yamada help 2961da4e3302SPhilip Prindeville This option enables system support for the Soekris Engineering net5501. 2962da4e3302SPhilip Prindeville 29633197059aSPhilip A. Prindevilleconfig GEOS 29643197059aSPhilip A. Prindeville bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 29653197059aSPhilip A. Prindeville select GPIOLIB 29663197059aSPhilip A. Prindeville depends on DMI 2967a7f7f624SMasahiro Yamada help 29683197059aSPhilip A. Prindeville This option enables system support for the Traverse Technologies GEOS. 29693197059aSPhilip A. Prindeville 29707d029125SVivien Didelotconfig TS5500 29717d029125SVivien Didelot bool "Technologic Systems TS-5500 platform support" 29727d029125SVivien Didelot depends on MELAN 29737d029125SVivien Didelot select CHECK_SIGNATURE 29747d029125SVivien Didelot select NEW_LEDS 29757d029125SVivien Didelot select LEDS_CLASS 2976a7f7f624SMasahiro Yamada help 29777d029125SVivien Didelot This option enables system support for the Technologic Systems TS-5500. 29787d029125SVivien Didelot 2979e279b6c1SSam Ravnborgendif # X86_32 2980e279b6c1SSam Ravnborg 298123ac4ae8SAndreas Herrmannconfig AMD_NB 2982e279b6c1SSam Ravnborg def_bool y 29830e152cd7SBorislav Petkov depends on CPU_SUP_AMD && PCI 2984e279b6c1SSam Ravnborg 2985e279b6c1SSam Ravnborgendmenu 2986e279b6c1SSam Ravnborg 29871572497cSChristoph Hellwigmenu "Binary Emulations" 2988e279b6c1SSam Ravnborg 2989e279b6c1SSam Ravnborgconfig IA32_EMULATION 2990e279b6c1SSam Ravnborg bool "IA32 Emulation" 2991e279b6c1SSam Ravnborg depends on X86_64 299239f88911SIngo Molnar select ARCH_WANT_OLD_COMPAT_IPC 2993d1603990SRandy Dunlap select BINFMT_ELF 299439f88911SIngo Molnar select COMPAT_OLD_SIGACTION 2995a7f7f624SMasahiro Yamada help 29965fd92e65SH. J. Lu Include code to run legacy 32-bit programs under a 29975fd92e65SH. J. Lu 64-bit kernel. You should likely turn this on, unless you're 29985fd92e65SH. J. Lu 100% sure that you don't have any 32-bit programs left. 2999e279b6c1SSam Ravnborg 3000a11e0975SNikolay Borisovconfig IA32_EMULATION_DEFAULT_DISABLED 3001a11e0975SNikolay Borisov bool "IA32 emulation disabled by default" 3002a11e0975SNikolay Borisov default n 3003a11e0975SNikolay Borisov depends on IA32_EMULATION 3004a11e0975SNikolay Borisov help 3005a11e0975SNikolay Borisov Make IA32 emulation disabled by default. This prevents loading 32-bit 3006a11e0975SNikolay Borisov processes and access to 32-bit syscalls. If unsure, leave it to its 3007a11e0975SNikolay Borisov default value. 3008a11e0975SNikolay Borisov 300983a44a4fSMasahiro Yamadaconfig X86_X32_ABI 30106ea30386SKees Cook bool "x32 ABI for 64-bit mode" 30119b54050bSBrian Gerst depends on X86_64 3012aaeed6ecSNathan Chancellor # llvm-objcopy does not convert x86_64 .note.gnu.property or 3013aaeed6ecSNathan Chancellor # compressed debug sections to x86_x32 properly: 3014aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/514 3015aaeed6ecSNathan Chancellor # https://github.com/ClangBuiltLinux/linux/issues/1141 3016aaeed6ecSNathan Chancellor depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) 3017a7f7f624SMasahiro Yamada help 30185fd92e65SH. J. Lu Include code to run binaries for the x32 native 32-bit ABI 30195fd92e65SH. J. Lu for 64-bit processors. An x32 process gets access to the 30205fd92e65SH. J. Lu full 64-bit register file and wide data path while leaving 30215fd92e65SH. J. Lu pointers at 32 bits for smaller memory footprint. 30225fd92e65SH. J. Lu 3023953fee1dSIngo Molnarconfig COMPAT_32 3024953fee1dSIngo Molnar def_bool y 3025953fee1dSIngo Molnar depends on IA32_EMULATION || X86_32 3026953fee1dSIngo Molnar select HAVE_UID16 3027953fee1dSIngo Molnar select OLD_SIGSUSPEND3 3028953fee1dSIngo Molnar 3029e279b6c1SSam Ravnborgconfig COMPAT 30303c2362e6SHarvey Harrison def_bool y 303183a44a4fSMasahiro Yamada depends on IA32_EMULATION || X86_X32_ABI 3032e279b6c1SSam Ravnborg 3033e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT 30343120e25eSJan Beulich def_bool y 3035a9251280SLinus Torvalds depends on COMPAT 3036ee009e4aSDavid Howells 3037e279b6c1SSam Ravnborgendmenu 3038e279b6c1SSam Ravnborg 3039e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP 3040e5beae16SKeith Packard def_bool y 3041e5beae16SKeith Packard depends on X86_32 3042e5beae16SKeith Packard 3043edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig" 30445e8ebd84SJason A. Donenfeld 30455e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler" 3046