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-rw-r--r--arch/x86/Kconfig1600
1 files changed, 960 insertions, 640 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 49270655e827..80527299f859 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -14,7 +14,6 @@ config X86_32
select ARCH_WANT_IPC_PARSE_VERSION
select CLKSRC_I8253
select CLONE_BACKWARDS
- select GENERIC_VDSO_32
select HAVE_DEBUG_STACKOVERFLOW
select KMAP_LOCAL
select MODULES_USE_ELF_REL
@@ -26,14 +25,18 @@ config X86_64
depends on 64BIT
# Options that are inherently 64-bit kernel only:
select ARCH_HAS_GIGANTIC_PAGE
+ select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
- select ARCH_USE_CMPXCHG_LOCKREF
+ select ARCH_SUPPORTS_PER_VMA_LOCK
+ select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
select HAVE_ARCH_SOFT_DIRTY
select MODULES_USE_ELF_RELA
select NEED_DMA_MAP_STATE
select SWIOTLB
select ARCH_HAS_ELFCORE_COMPAT
select ZONE_DMA32
+ select EXECMEM if DYNAMIC_FTRACE
+ select ACPI_MRRM if ACPI
config FORCE_DYNAMIC_FTRACE
def_bool y
@@ -41,11 +44,11 @@ config FORCE_DYNAMIC_FTRACE
depends on FUNCTION_TRACER
select DYNAMIC_FTRACE
help
- We keep the static function tracing (!DYNAMIC_FTRACE) around
- in order to test the non static function tracing in the
- generic code, as other architectures still use it. But we
- only need to keep it around for x86_64. No need to keep it
- for x86_32. For x86_32, force DYNAMIC_FTRACE.
+ We keep the static function tracing (!DYNAMIC_FTRACE) around
+ in order to test the non static function tracing in the
+ generic code, as other architectures still use it. But we
+ only need to keep it around for x86_64. No need to keep it
+ for x86_32. For x86_32, force DYNAMIC_FTRACE.
#
# Arch settings
#
@@ -59,31 +62,45 @@ config X86
#
select ACPI_LEGACY_TABLES_LOOKUP if ACPI
select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
+ select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
select ARCH_32BIT_OFF_T if X86_32
select ARCH_CLOCKSOURCE_INIT
+ select ARCH_CONFIGURES_CPU_MITIGATIONS
+ select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
- select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 || (X86_32 && HIGHMEM)
+ select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
+ select ARCH_HAS_CPU_ATTACK_VECTORS if CPU_MITIGATIONS
select ARCH_HAS_CACHE_LINE_SIZE
+ select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
+ select ARCH_HAS_CPU_FINALIZE_INIT
+ select ARCH_HAS_CPU_PASID if IOMMU_SVA
+ select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
select ARCH_HAS_DEVMEM_IS_ALLOWED
+ select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN
select ARCH_HAS_EARLY_DEBUG if KGDB
select ARCH_HAS_ELF_RANDOMIZE
+ select ARCH_HAS_EXECMEM_ROX if X86_64 && STRICT_MODULE_RWX
select ARCH_HAS_FAST_MULTIPLIER
- select ARCH_HAS_FILTER_PGPROT
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_GCOV_PROFILE_ALL
- select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION
+ select ARCH_HAS_KCOV if X86_64
+ select ARCH_HAS_KERNEL_FPU_SUPPORT
select ARCH_HAS_MEM_ENCRYPT
select ARCH_HAS_MEMBARRIER_SYNC_CORE
+ select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
select ARCH_HAS_PMEM_API if X86_64
- select ARCH_HAS_PTE_DEVMAP if X86_64
+ select ARCH_HAS_PREEMPT_LAZY
+ select ARCH_HAS_PTDUMP
select ARCH_HAS_PTE_SPECIAL
+ select ARCH_HAS_HW_PTE_YOUNG
+ select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2
select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
select ARCH_HAS_COPY_MC if X86_64
select ARCH_HAS_SET_MEMORY
@@ -92,10 +109,12 @@ config X86
select ARCH_HAS_STRICT_MODULE_RWX
select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
select ARCH_HAS_SYSCALL_WRAPPER
- select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select ARCH_HAS_UBSAN
select ARCH_HAS_DEBUG_WX
select ARCH_HAS_ZONE_DMA_SET if EXPERT
select ARCH_HAVE_NMI_SAFE_CMPXCHG
+ select ARCH_HAVE_EXTRA_ELF_NOTES
+ select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
select ARCH_MIGHT_HAVE_PC_PARPORT
select ARCH_MIGHT_HAVE_PC_SERIO
@@ -103,11 +122,19 @@ config X86
select ARCH_SUPPORTS_ACPI
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC
+ select ARCH_SUPPORTS_HUGETLBFS
+ select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64
select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096
+ select ARCH_SUPPORTS_CFI if X86_64
+ select ARCH_USES_CFI_TRAPS if X86_64 && CFI
select ARCH_SUPPORTS_LTO_CLANG
select ARCH_SUPPORTS_LTO_CLANG_THIN
+ select ARCH_SUPPORTS_RT
+ select ARCH_SUPPORTS_AUTOFDO_CLANG
+ select ARCH_SUPPORTS_PROPELLER_CLANG if X86_64
select ARCH_USE_BUILTIN_BSWAP
+ select ARCH_USE_CMPXCHG_LOCKREF if X86_CX8
select ARCH_USE_MEMTEST
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
@@ -116,24 +143,33 @@ config X86
select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
select ARCH_WANTS_DYNAMIC_TASK_STRUCT
select ARCH_WANTS_NO_INSTR
- select ARCH_WANT_HUGE_PMD_SHARE
+ select ARCH_WANT_GENERAL_HUGETLB
+ select ARCH_WANT_HUGE_PMD_SHARE if X86_64
select ARCH_WANT_LD_ORPHAN_WARN
+ select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP if X86_64
+ select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP if X86_64
+ select ARCH_WANT_HUGETLB_VMEMMAP_PREINIT if X86_64
select ARCH_WANTS_THP_SWAP if X86_64
+ select ARCH_HAS_PARANOID_L1D_FLUSH
+ select ARCH_WANT_IRQS_OFF_ACTIVATE_MM
select BUILDTIME_TABLE_SORT
select CLKEVT_I8253
- select CLOCKSOURCE_VALIDATE_LAST_CYCLE
select CLOCKSOURCE_WATCHDOG
- select DCACHE_WORD_ACCESS
+ # Word-size accesses may read uninitialized data past the trailing \0
+ # in strings and cause false KMSAN reports.
+ select DCACHE_WORD_ACCESS if !KMSAN
+ select DYNAMIC_SIGFRAME
select EDAC_ATOMIC_SCRUB
select EDAC_SUPPORT
select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
+ select GENERIC_CLOCKEVENTS_BROADCAST_IDLE if GENERIC_CLOCKEVENTS_BROADCAST
select GENERIC_CLOCKEVENTS_MIN_ADJUST
select GENERIC_CMOS_UPDATE
select GENERIC_CPU_AUTOPROBE
+ select GENERIC_CPU_DEVICES
select GENERIC_CPU_VULNERABILITIES
select GENERIC_EARLY_IOREMAP
select GENERIC_ENTRY
- select GENERIC_FIND_FIRST_BIT
select GENERIC_IOMAP
select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
@@ -142,34 +178,34 @@ config X86
select GENERIC_IRQ_RESERVATION_MODE
select GENERIC_IRQ_SHOW
select GENERIC_PENDING_IRQ if SMP
- select GENERIC_PTDUMP
select GENERIC_SMP_IDLE_THREAD
- select GENERIC_STRNCPY_FROM_USER
- select GENERIC_STRNLEN_USER
select GENERIC_TIME_VSYSCALL
select GENERIC_GETTIMEOFDAY
- select GENERIC_VDSO_TIME_NS
- select GUP_GET_PTE_LOW_HIGH if X86_PAE
+ select GENERIC_VDSO_OVERFLOW_PROTECT
+ select GUP_GET_PXX_LOW_HIGH if X86_PAE
select HARDIRQS_SW_RESEND
select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
+ select HAS_IOPORT
select HAVE_ACPI_APEI if ACPI
select HAVE_ACPI_APEI_NMI if ACPI
- select HAVE_ALIGNED_STRUCT_PAGE if SLUB
+ select HAVE_ALIGNED_STRUCT_PAGE
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
+ select HAVE_ARCH_HUGE_VMALLOC if X86_64
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_KASAN if X86_64
select HAVE_ARCH_KASAN_VMALLOC if X86_64
select HAVE_ARCH_KFENCE
+ select HAVE_ARCH_KMSAN if X86_64
select HAVE_ARCH_KGDB
+ select HAVE_ARCH_KSTACK_ERASE
select HAVE_ARCH_MMAP_RND_BITS if MMU
select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
select HAVE_ARCH_PREL32_RELOCATIONS
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_THREAD_STRUCT_WHITELIST
- select HAVE_ARCH_STACKLEAK
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
@@ -181,31 +217,39 @@ config X86
select HAVE_ASM_MODVERSIONS
select HAVE_CMPXCHG_DOUBLE
select HAVE_CMPXCHG_LOCAL
- select HAVE_CONTEXT_TRACKING if X86_64
- select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING
+ select HAVE_CONTEXT_TRACKING_USER if X86_64
+ select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER
select HAVE_C_RECORDMCOUNT
- select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION
+ select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
+ select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT
+ select HAVE_BUILDTIME_MCOUNT_SORT
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64
+ select HAVE_FTRACE_REGS_HAVING_PT_REGS if X86_64
select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+ select HAVE_DYNAMIC_FTRACE_WITH_JMP if X86_64
+ select HAVE_SAMPLE_FTRACE_DIRECT if X86_64
+ select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64
select HAVE_EBPF_JIT
select HAVE_EFFICIENT_UNALIGNED_ACCESS
- select HAVE_EISA
+ select HAVE_EISA if X86_32
select HAVE_EXIT_THREAD
- select HAVE_FAST_GUP
+ select HAVE_GENERIC_TIF_BITS
+ select HAVE_GUP_FAST
select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
- select HAVE_FTRACE_MCOUNT_RECORD
- select HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_FTRACE_GRAPH_FUNC if HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_FUNCTION_GRAPH_FREGS if HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE)
select HAVE_FUNCTION_TRACER
select HAVE_GCC_PLUGINS
select HAVE_HW_BREAKPOINT
- select HAVE_IDE
select HAVE_IOREMAP_PROT
select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
select HAVE_IRQ_TIME_ACCOUNTING
+ select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_LZ4
@@ -217,14 +261,19 @@ config X86
select HAVE_KPROBES_ON_FTRACE
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_KRETPROBES
- select HAVE_KVM
+ select HAVE_RETHOOK
+ select HAVE_KLP_BUILD if X86_64
select HAVE_LIVEPATCH if X86_64
select HAVE_MIXED_BREAKPOINTS_REGS
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_MOVE_PMD
select HAVE_MOVE_PUD
+ select HAVE_NOINSTR_HACK if HAVE_OBJTOOL
select HAVE_NMI
+ select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL
+ select HAVE_OBJTOOL if X86_64
select HAVE_OPTPROBES
+ select HAVE_PAGE_SIZE_4KB
select HAVE_PCSPKR_PLATFORM
select HAVE_PERF_EVENTS
select HAVE_PERF_EVENTS_NMI
@@ -232,41 +281,61 @@ config X86
select HAVE_PCI
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
- select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
+ select ASYNC_KERNEL_PGTABLE_FREE if IOMMU_SVA
+ select MMU_GATHER_RCU_TABLE_FREE
+ select MMU_GATHER_MERGE_VMAS
select HAVE_POSIX_CPU_TIMERS_TASK_WORK
select HAVE_REGS_AND_STACK_ACCESS_API
- select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
+ select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION
select HAVE_FUNCTION_ARG_ACCESS_API
+ select HAVE_SETUP_PER_CPU_AREA
select HAVE_SOFTIRQ_ON_OWN_STACK
- select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
- select HAVE_STACK_VALIDATION if X86_64
+ select HAVE_STACKPROTECTOR
+ select HAVE_STACK_VALIDATION if HAVE_OBJTOOL
select HAVE_STATIC_CALL
- select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION
- select HAVE_PREEMPT_DYNAMIC
+ select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL
+ select HAVE_PREEMPT_DYNAMIC_CALL
select HAVE_RSEQ
+ select HAVE_RUST if X86_64
select HAVE_SYSCALL_TRACEPOINTS
+ select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL
select HAVE_UNSTABLE_SCHED_CLOCK
+ select HAVE_UNWIND_USER_FP if X86_64
select HAVE_USER_RETURN_NOTIFIER
select HAVE_GENERIC_VDSO
+ select VDSO_GETRANDOM if X86_64
+ select HOTPLUG_PARALLEL if SMP && X86_64
select HOTPLUG_SMT if SMP
+ select HOTPLUG_SPLIT_STARTUP if SMP && X86_32
select IRQ_FORCED_THREADING
+ select LOCK_MM_AND_FIND_VMA
+ select NEED_PER_CPU_EMBED_FIRST_CHUNK
+ select NEED_PER_CPU_PAGE_FIRST_CHUNK
select NEED_SG_DMA_LENGTH
+ select NUMA_MEMBLKS if NUMA
select PCI_DOMAINS if PCI
select PCI_LOCKLESS_CONFIG if PCI
select PERF_EVENTS
select RTC_LIB
select RTC_MC146818_LIB
select SPARSE_IRQ
- select SRCU
- select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
select SYSCTL_EXCEPTION_TRACE
select THREAD_INFO_IN_TASK
+ select TRACE_IRQFLAGS_SUPPORT
+ select TRACE_IRQFLAGS_NMI_SUPPORT
select USER_STACKTRACE_SUPPORT
- select VIRT_TO_BUS
select HAVE_ARCH_KCSAN if X86_64
- select X86_FEATURE_NAMES if PROC_FS
select PROC_PID_ARCH_STATUS if PROC_FS
+ select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX
+ select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16
+ select FUNCTION_ALIGNMENT_4B
imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
+ select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
+ select ARCH_SUPPORTS_PT_RECLAIM if X86_64
+ select ARCH_SUPPORTS_SCHED_SMT if SMP
+ select SCHED_SMT if SMP
+ select ARCH_SUPPORTS_SCHED_CLUSTER if SMP
+ select ARCH_SUPPORTS_SCHED_MC if SMP
config INSTRUCTION_DECODER
def_bool y
@@ -307,10 +376,14 @@ config GENERIC_ISA_DMA
def_bool y
depends on ISA_DMA_API
+config GENERIC_CSUM
+ bool
+ default y if KMSAN || KASAN
+
config GENERIC_BUG
def_bool y
depends on BUG
- select GENERIC_BUG_RELATIVE_POINTERS if X86_64
+ select GENERIC_BUG_RELATIVE_POINTERS
config GENERIC_BUG_RELATIVE_POINTERS
bool
@@ -325,27 +398,12 @@ config GENERIC_CALIBRATE_DELAY
config ARCH_HAS_CPU_RELAX
def_bool y
-config ARCH_HAS_FILTER_PGPROT
- def_bool y
-
-config HAVE_SETUP_PER_CPU_AREA
- def_bool y
-
-config NEED_PER_CPU_EMBED_FIRST_CHUNK
- def_bool y
-
-config NEED_PER_CPU_PAGE_FIRST_CHUNK
- def_bool y
-
config ARCH_HIBERNATION_POSSIBLE
def_bool y
config ARCH_SUSPEND_POSSIBLE
def_bool y
-config ARCH_WANT_GENERAL_HUGETLB
- def_bool y
-
config AUDIT_ARCH
def_bool y if X86_64
@@ -358,14 +416,6 @@ config HAVE_INTEL_TXT
def_bool y
depends on INTEL_IOMMU && ACPI
-config X86_32_SMP
- def_bool y
- depends on X86_32 && SMP
-
-config X86_64_SMP
- def_bool y
- depends on X86_64 && SMP
-
config ARCH_SUPPORTS_UPROBES
def_bool y
@@ -377,20 +427,10 @@ config DYNAMIC_PHYSICAL_MASK
config PGTABLE_LEVELS
int
- default 5 if X86_5LEVEL
- default 4 if X86_64
+ default 5 if X86_64
default 3 if X86_PAE
default 2
-config CC_HAS_SANE_STACKPROTECTOR
- bool
- default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
- default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
- help
- We have to make sure stack protector is unconditionally disabled if
- the compiler produces broken code or if it does not let us control
- the segment on 32-bit kernels.
-
menu "Processor type and features"
config SMP
@@ -415,31 +455,57 @@ config SMP
Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
Management" code will be disabled if you say Y here.
- See also <file:Documentation/x86/i386/IO-APIC.rst>,
+ See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
<file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
<http://www.tldp.org/docs.html#howto>.
If you don't know what to do here, say N.
-config X86_FEATURE_NAMES
- bool "Processor feature human-readable names" if EMBEDDED
+config X86_X2APIC
+ bool "x2APIC interrupt controller architecture support"
+ depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
default y
help
- This option compiles in a table of x86 feature bits and corresponding
- names. This is required to support /proc/cpuinfo and a few kernel
- messages. You can disable this to save space, at the expense of
- making those few kernel messages show numeric feature bits instead.
+ x2APIC is an interrupt controller architecture, a component of which
+ (the local APIC) is present in the CPU. It allows faster access to
+ the local APIC and supports a larger number of CPUs in the system
+ than the predecessors.
+
+ x2APIC was introduced in Intel CPUs around 2008 and in AMD EPYC CPUs
+ in 2019, but it can be disabled by the BIOS. It is also frequently
+ emulated in virtual machines, even when the host CPU does not support
+ it. Support in the CPU can be checked by executing
+ grep x2apic /proc/cpuinfo
+
+ If this configuration option is disabled, the kernel will boot with
+ very reduced functionality and performance on some platforms that
+ have x2APIC enabled. On the other hand, on hardware that does not
+ support x2APIC, a kernel with this option enabled will just fallback
+ to older APIC implementations.
If in doubt, say Y.
-config X86_X2APIC
- bool "Support x2apic"
- depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
+config AMD_SECURE_AVIC
+ bool "AMD Secure AVIC"
+ depends on AMD_MEM_ENCRYPT && X86_X2APIC
help
- This enables x2apic support on CPUs that have this feature.
+ Enable this to get AMD Secure AVIC support on guests that have this feature.
+
+ AMD Secure AVIC provides hardware acceleration for performance sensitive
+ APIC accesses and support for managing guest owned APIC state for SEV-SNP
+ guests. Secure AVIC does not support xAPIC mode. It has functional
+ dependency on x2apic being enabled in the guest.
- This allows 32-bit apic IDs (so it can support very large systems),
- and accesses the local apic via MSRs not via mmio.
+ If you don't know what to do here, say N.
+
+config X86_POSTED_MSI
+ bool "Enable MSI and MSI-x delivery by posted interrupts"
+ depends on X86_64 && IRQ_REMAP
+ help
+ This enables MSIs that are under interrupt remapping to be delivered as
+ posted interrupts to the host kernel. Interrupt throughput can
+ potentially be improved by coalescing CPU notifications during high
+ frequency bursts.
If you don't know what to do here, say N.
@@ -451,24 +517,13 @@ config X86_MPPARSE
For old smp systems that do not have proper acpi support. Newer systems
(esp with 64bit cpus) with acpi support, MADT and DSDT will override it
-config GOLDFISH
- def_bool y
- depends on X86_GOLDFISH
-
-config RETPOLINE
- bool "Avoid speculative indirect branches in kernel"
- default y
- help
- Compile kernel with the retpoline compiler options to guard against
- kernel-to-user data leaks by avoiding speculative indirect
- branches. Requires a compiler with -mindirect-branch=thunk-extern
- support for full protection. The kernel may run slower.
-
config X86_CPU_RESCTRL
bool "x86 CPU resource control support"
depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
- select KERNFS
- select PROC_CPU_RESCTRL if PROC_FS
+ depends on MISC_FILESYSTEMS
+ select ARCH_HAS_CPU_RESCTRL
+ select RESCTRL_FS
+ select RESCTRL_FS_PSEUDO_LOCK
help
Enable x86 CPU resource control support.
@@ -485,12 +540,14 @@ config X86_CPU_RESCTRL
Say N if unsure.
-if X86_32
-config X86_BIGSMP
- bool "Support for big SMP systems with more than 8 CPUs"
- depends on SMP
+config X86_FRED
+ bool "Flexible Return and Event Delivery"
+ depends on X86_64
help
- This option is needed for the systems that have more than 8 CPUs.
+ When enabled, try to use Flexible Return and Event Delivery
+ instead of the legacy SYSCALL/SYSENTER/IDT architecture for
+ ring transitions and exception/interrupt handling if the
+ system supports it.
config X86_EXTENDED_PLATFORM
bool "Support for extended (non-PC) x86 platforms"
@@ -501,36 +558,25 @@ config X86_EXTENDED_PLATFORM
systems out there.)
If you enable this option then you'll be able to select support
- for the following (non-PC) 32 bit x86 platforms:
- Goldfish (Android emulator)
- AMD Elan
- RDC R-321x SoC
- SGI 320/540 (Visual Workstation)
- STA2X11-based (e.g. Northville)
- Moorestown MID devices
+ for the following non-PC x86 platforms, depending on the value of
+ CONFIG_64BIT.
- If you have one of these systems, or if you want to build a
- generic distribution kernel, say Y here - otherwise say N.
-endif
-
-if X86_64
-config X86_EXTENDED_PLATFORM
- bool "Support for extended (non-PC) x86 platforms"
- default y
- help
- If you disable this option then the kernel will only support
- standard PC platforms. (which covers the vast majority of
- systems out there.)
+ 32-bit platforms (CONFIG_64BIT=n):
+ Goldfish (mostly Android emulator)
+ Intel CE media processor (CE4100) SoC
+ Intel Quark
+ RDC R-321x SoC
- If you enable this option then you'll be able to select support
- for the following (non-PC) 64 bit x86 platforms:
+ 64-bit platforms (CONFIG_64BIT=y):
Numascale NumaChip
ScaleMP vSMP
SGI Ultraviolet
+ Merrifield/Moorefield MID devices
+ Goldfish (mostly Android emulator)
If you have one of these systems, or if you want to build a
generic distribution kernel, say Y here - otherwise say N.
-endif
+
# This is an alphabetically sorted list of 64 bit extended platforms
# Please maintain the alphabetic order if and when there are additions
config X86_NUMACHIP
@@ -571,16 +617,42 @@ config X86_UV
This option is needed in order to support SGI Ultraviolet systems.
If you don't have one of these, you should say N here.
-# Following is an alphabetically sorted list of 32 bit extended platforms
-# Please maintain the alphabetic order if and when there are additions
+config X86_INTEL_MID
+ bool "Intel Z34xx/Z35xx MID platform support"
+ depends on X86_EXTENDED_PLATFORM
+ depends on X86_PLATFORM_DEVICES
+ depends on PCI
+ depends on X86_64 || (EXPERT && PCI_GOANY)
+ depends on X86_IO_APIC
+ select I2C
+ select DW_APB_TIMER
+ select INTEL_SCU_PCI
+ help
+ Select to build a kernel capable of supporting 64-bit Intel MID
+ (Mobile Internet Device) platform systems which do not have
+ the PCI legacy interfaces.
+
+ The only supported devices are the 22nm Merrified (Z34xx)
+ and Moorefield (Z35xx) SoC used in the Intel Edison board and
+ a small number of Android devices such as the Asus Zenfone 2,
+ Asus FonePad 8 and Dell Venue 7.
+
+ If you are building for a PC class system or non-MID tablet
+ SoCs like Bay Trail (Z36xx/Z37xx), say N here.
+
+ Intel MID platforms are based on an Intel processor and chipset which
+ consume less power than most of the x86 derivatives.
config X86_GOLDFISH
bool "Goldfish (Virtual Platform)"
depends on X86_EXTENDED_PLATFORM
help
- Enable support for the Goldfish virtual platform used primarily
- for Android development. Unless you are building for the Android
- Goldfish emulator say N here.
+ Enable support for the Goldfish virtual platform used primarily
+ for Android development. Unless you are building for the Android
+ Goldfish emulator say N here.
+
+# Following is an alphabetically sorted list of 32 bit extended platforms
+# Please maintain the alphabetic order if and when there are additions
config X86_INTEL_CE
bool "CE4100 TV platform"
@@ -597,26 +669,6 @@ config X86_INTEL_CE
This option compiles in support for the CE4100 SOC for settop
boxes and media devices.
-config X86_INTEL_MID
- bool "Intel MID platform support"
- depends on X86_EXTENDED_PLATFORM
- depends on X86_PLATFORM_DEVICES
- depends on PCI
- depends on X86_64 || (PCI_GOANY && X86_32)
- depends on X86_IO_APIC
- select I2C
- select DW_APB_TIMER
- select APB_TIMER
- select INTEL_SCU_PCI
- select MFD_INTEL_MSIC
- help
- Select to build a kernel capable of supporting Intel MID (Mobile
- Internet Device) platform systems which do not have the PCI legacy
- interfaces. If you are building for a PC class system say N here.
-
- Intel MID platforms are based on an Intel processor and chipset which
- consume less power than most of the x86 derivatives.
-
config X86_INTEL_QUARK
bool "Intel Quark platform support"
depends on X86_32
@@ -634,6 +686,17 @@ config X86_INTEL_QUARK
Say Y here if you have a Quark based system such as the Arduino
compatible Intel Galileo.
+config X86_RDC321X
+ bool "RDC R-321x SoC"
+ depends on X86_32
+ depends on X86_EXTENDED_PLATFORM
+ select M486
+ select X86_REBOOTFIXUPS
+ help
+ This option is needed for RDC R-321x system-on-chip, also known
+ as R-8610-(G).
+ If you don't have one of these chips, you should say N here.
+
config X86_INTEL_LPSS
bool "Intel Low Power Subsystem Support"
depends on X86 && ACPI && PCI
@@ -687,29 +750,6 @@ config IOSF_MBI_DEBUG
If you don't require the option or are in doubt, say N.
-config X86_RDC321X
- bool "RDC R-321x SoC"
- depends on X86_32
- depends on X86_EXTENDED_PLATFORM
- select M486
- select X86_REBOOTFIXUPS
- help
- This option is needed for RDC R-321x system-on-chip, also known
- as R-8610-(G).
- If you don't have one of these chips, you should say N here.
-
-config X86_32_NON_STANDARD
- bool "Support non-standard 32-bit SMP architectures"
- depends on X86_32 && SMP
- depends on X86_EXTENDED_PLATFORM
- help
- This option compiles in the bigsmp and STA2X11 default
- subarchitectures. It is intended for a generic binary
- kernel. If you select them all, kernel will probe it one by
- one and will fallback to default.
-
-# Alphabetically sorted list of Non standard 32 bit platforms
-
config X86_SUPPORTS_MEMORY_FAILURE
def_bool y
# MCE code calls memory_failure():
@@ -719,19 +759,6 @@ config X86_SUPPORTS_MEMORY_FAILURE
depends on X86_64 || !SPARSEMEM
select ARCH_SUPPORTS_MEMORY_FAILURE
-config STA2X11
- bool "STA2X11 Companion Chip Support"
- depends on X86_32_NON_STANDARD && PCI
- select SWIOTLB
- select MFD_STA2X11
- select GPIOLIB
- help
- This adds support for boards based on the STA2X11 IO-Hub,
- a.k.a. "ConneXt". The chip is used in place of the standard
- PC chipset, so all "standard" peripherals are missing. If this
- option is selected the kernel will still be able to boot on
- standard PC machines.
-
config X86_32_IRIS
tristate "Eurobraille/Iris poweroff module"
depends on X86_32
@@ -780,6 +807,7 @@ config PARAVIRT
config PARAVIRT_XXL
bool
+ depends on X86_64
config PARAVIRT_DEBUG
bool "paravirt-ops debugging"
@@ -866,7 +894,34 @@ config ACRN_GUEST
IOT with small footprint and real-time features. More details can be
found in https://projectacrn.org/.
-endif #HYPERVISOR_GUEST
+config BHYVE_GUEST
+ bool "Bhyve (BSD Hypervisor) Guest support"
+ depends on X86_64
+ help
+ This option allows to run Linux to recognise when it is running as a
+ guest in the Bhyve hypervisor, and to support more than 255 vCPUs when
+ when doing so. More details about Bhyve can be found at https://bhyve.org
+ and https://wiki.freebsd.org/bhyve/.
+
+config INTEL_TDX_GUEST
+ bool "Intel TDX (Trust Domain Extensions) - Guest Support"
+ depends on X86_64 && CPU_SUP_INTEL
+ depends on X86_X2APIC
+ depends on EFI_STUB
+ depends on PARAVIRT
+ select ARCH_HAS_CC_PLATFORM
+ select X86_MEM_ENCRYPT
+ select X86_MCE
+ select UNACCEPTED_MEMORY
+ help
+ Support running as a guest under Intel TDX. Without this support,
+ the guest kernel can not boot or run under TDX.
+ TDX includes memory encryption and integrity capabilities
+ which protect the confidentiality and integrity of guest
+ memory contents and CPU state. TDX guests are protected from
+ some attacks from the VMM.
+
+endif # HYPERVISOR_GUEST
source "arch/x86/Kconfig.cpu"
@@ -907,7 +962,6 @@ config DMI
config GART_IOMMU
bool "Old AMD GART IOMMU support"
- select DMA_OPS
select IOMMU_HELPER
select SWIOTLB
depends on X86_64 && PCI && AMD_NB
@@ -928,6 +982,12 @@ config GART_IOMMU
If unsure, say Y.
+config BOOT_VESA_SUPPORT
+ bool
+ help
+ If true, at least one selected framebuffer driver can take advantage
+ of VESA video modes set at an early boot stage via the vga= parameter.
+
config MAXSMP
bool "Enable Maximum number of SMP Processors and NUMA Nodes"
depends on X86_64 && SMP && DEBUG_KERNEL
@@ -959,8 +1019,7 @@ config NR_CPUS_RANGE_BEGIN
config NR_CPUS_RANGE_END
int
depends on X86_32
- default 64 if SMP && X86_BIGSMP
- default 8 if SMP && !X86_BIGSMP
+ default 8 if SMP
default 1 if !SMP
config NR_CPUS_RANGE_END
@@ -973,7 +1032,6 @@ config NR_CPUS_RANGE_END
config NR_CPUS_DEFAULT
int
depends on X86_32
- default 32 if X86_BIGSMP
default 8 if SMP
default 1 if !SMP
@@ -997,22 +1055,11 @@ config NR_CPUS
This is purely to save memory: each supported CPU adds about 8KB
to the kernel image.
-config SCHED_SMT
- def_bool y if SMP
-
-config SCHED_MC
- def_bool y
- prompt "Multi-core scheduler support"
- depends on SMP
- help
- Multi-core scheduler support improves the CPU scheduler's decision
- making when dealing with multi-core CPU chips at a cost of slightly
- increased overhead in some places. If unsure say N here.
-
config SCHED_MC_PRIO
bool "CPU core priorities scheduler support"
- depends on SCHED_MC && CPU_SUP_INTEL
- select X86_INTEL_PSTATE
+ depends on SCHED_MC
+ select X86_INTEL_PSTATE if CPU_SUP_INTEL
+ select X86_AMD_PSTATE if CPU_SUP_AMD && ACPI
select CPU_FREQ
default y
help
@@ -1037,7 +1084,7 @@ config UP_LATE_INIT
config X86_UP_APIC
bool "Local APIC support on uniprocessors" if !PCI_MSI
default PCI_MSI
- depends on X86_32 && !SMP && !X86_32_NON_STANDARD
+ depends on X86_32 && !SMP
help
A local APIC (Advanced Programmable Interrupt Controller) is an
integrated interrupt controller in the CPU. If you have a single-CPU
@@ -1062,9 +1109,15 @@ config X86_UP_IOAPIC
config X86_LOCAL_APIC
def_bool y
- depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
+ depends on X86_64 || SMP || X86_UP_APIC || PCI_MSI
select IRQ_DOMAIN_HIERARCHY
- select PCI_MSI_IRQ_DOMAIN if PCI_MSI
+
+config ACPI_MADT_WAKEUP
+ def_bool y
+ depends on X86_64
+ depends on ACPI
+ depends on SMP
+ depends on X86_LOCAL_APIC
config X86_IO_APIC
def_bool y
@@ -1116,16 +1169,16 @@ config X86_MCE_INTEL
prompt "Intel MCE features"
depends on X86_MCE && X86_LOCAL_APIC
help
- Additional support for intel specific MCE features such as
- the thermal monitor.
+ Additional support for intel specific MCE features such as
+ the thermal monitor.
config X86_MCE_AMD
def_bool y
prompt "AMD MCE features"
- depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
+ depends on X86_MCE && X86_LOCAL_APIC
help
- Additional support for AMD specific MCE features such as
- the DRAM Error Threshold.
+ Additional support for AMD specific MCE features such as
+ the DRAM Error Threshold.
config X86_ANCIENT_MCE
bool "Support for old Pentium 5 / WinChip machine checks"
@@ -1203,18 +1256,18 @@ config X86_VSYSCALL_EMULATION
default y
depends on X86_64
help
- This enables emulation of the legacy vsyscall page. Disabling
- it is roughly equivalent to booting with vsyscall=none, except
- that it will also disable the helpful warning if a program
- tries to use a vsyscall. With this option set to N, offending
- programs will just segfault, citing addresses of the form
- 0xffffffffff600?00.
+ This enables emulation of the legacy vsyscall page. Disabling
+ it is roughly equivalent to booting with vsyscall=none, except
+ that it will also disable the helpful warning if a program
+ tries to use a vsyscall. With this option set to N, offending
+ programs will just segfault, citing addresses of the form
+ 0xffffffffff600?00.
- This option is required by many programs built before 2013, and
- care should be used even with newer programs if set to N.
+ This option is required by many programs built before 2013, and
+ care should be used even with newer programs if set to N.
- Disabling this option saves about 7K of kernel size and
- possibly 4K of additional runtime pagetable memory.
+ Disabling this option saves about 7K of kernel size and
+ possibly 4K of additional runtime pagetable memory.
config X86_IOPL_IOPERM
bool "IOPERM and IOPL Emulation"
@@ -1250,22 +1303,6 @@ config TOSHIBA
Say Y if you intend to run this kernel on a Toshiba portable.
Say N otherwise.
-config I8K
- tristate "Dell i8k legacy laptop support"
- select HWMON
- select SENSORS_DELL_SMM
- help
- This option enables legacy /proc/i8k userspace interface in hwmon
- dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
- temperature and allows controlling fan speeds of Dell laptops via
- System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
- it reports also power and hotkey status. For fan speed control is
- needed userspace package i8kutils.
-
- Say Y if you intend to run this kernel on old Dell laptops or want to
- use userspace package i8kutils.
- Say N otherwise.
-
config X86_REBOOTFIXUPS
bool "Enable X86 board specific fixups for reboot"
depends on X86_32
@@ -1284,56 +1321,57 @@ config X86_REBOOTFIXUPS
Say N otherwise.
config MICROCODE
- bool "CPU microcode loading support"
- default y
+ def_bool y
depends on CPU_SUP_AMD || CPU_SUP_INTEL
- help
- If you say Y here, you will be able to update the microcode on
- Intel and AMD processors. The Intel support is for the IA32 family,
- e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
- AMD support is for families 0x10 and later. You will obviously need
- the actual microcode binary data itself which is not shipped with
- the Linux kernel.
-
- The preferred method to load microcode from a detached initrd is described
- in Documentation/x86/microcode.rst. For that you need to enable
- CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
- initrd for microcode blobs.
+ select CRYPTO_LIB_SHA256 if CPU_SUP_AMD
- In addition, you can build the microcode into the kernel. For that you
- need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
- config option.
+config MICROCODE_INITRD32
+ def_bool y
+ depends on MICROCODE && X86_32 && BLK_DEV_INITRD
-config MICROCODE_INTEL
- bool "Intel microcode loading support"
- depends on MICROCODE
- default MICROCODE
+config MICROCODE_LATE_LOADING
+ bool "Late microcode loading (DANGEROUS)"
+ default n
+ depends on MICROCODE && SMP
+ help
+ Loading microcode late, when the system is up and executing instructions
+ is a tricky business and should be avoided if possible. Just the sequence
+ of synchronizing all cores and SMT threads is one fragile dance which does
+ not guarantee that cores might not softlock after the loading. Therefore,
+ use this at your own risk. Late loading taints the kernel unless the
+ microcode header indicates that it is safe for late loading via the
+ minimal revision check. This minimal revision check can be enforced on
+ the kernel command line with "microcode=force_minrev".
+
+config MICROCODE_LATE_FORCE_MINREV
+ bool "Enforce late microcode loading minimal revision check"
+ default n
+ depends on MICROCODE_LATE_LOADING
help
- This options enables microcode patch loading support for Intel
- processors.
+ To prevent that users load microcode late which modifies already
+ in use features, newer microcode patches have a minimum revision field
+ in the microcode header, which tells the kernel which minimum
+ revision must be active in the CPU to safely load that new microcode
+ late into the running system. If disabled the check will not
+ be enforced but the kernel will be tainted when the minimal
+ revision check fails.
- For the current Intel microcode data package go to
- <https://downloadcenter.intel.com> and search for
- 'Linux Processor Microcode Data File'.
+ This minimal revision check can also be controlled via the
+ "microcode=force_minrev" parameter on the kernel command line.
-config MICROCODE_AMD
- bool "AMD microcode loading support"
- depends on MICROCODE
- help
- If you select this option, microcode patch loading support for AMD
- processors will be enabled.
+ If unsure say Y.
-config MICROCODE_OLD_INTERFACE
- bool "Ancient loading interface (DEPRECATED)"
+config MICROCODE_DBG
+ bool "Enable microcode loader debugging"
default n
depends on MICROCODE
help
- DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
- which was used by userspace tools like iucode_tool and microcode.ctl.
- It is inadequate because it runs too late to be able to properly
- load microcode on a machine and it needs special tools. Instead, you
- should've switched to the early loading method with the initrd or
- builtin microcode by now: Documentation/x86/microcode.rst
+ Enable code which allows for debugging the microcode loader in
+ a guest. Meaning the patch loading is simulated but everything else
+ related to patch parsing and handling is done as on baremetal with
+ the purpose of debugging solely the software side of things.
+
+ You almost certainly want to say n here.
config X86_MSR
tristate "/dev/cpu/*/msr - Model-specific register support"
@@ -1352,15 +1390,11 @@ config X86_CPUID
with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
/dev/cpu/31/cpuid.
-choice
- prompt "High Memory Support"
- default HIGHMEM4G
+config HIGHMEM4G
+ bool "High Memory Support"
depends on X86_32
-
-config NOHIGHMEM
- bool "off"
help
- Linux can use up to 64 Gigabytes of physical memory on x86 systems.
+ Linux can use up to 4 Gigabytes of physical memory on x86 systems.
However, the address space of 32-bit x86 processors is only 4
Gigabytes large. That means that, if you have a large amount of
physical memory, not all of it can be "permanently mapped" by the
@@ -1376,38 +1410,9 @@ config NOHIGHMEM
possible.
If the machine has between 1 and 4 Gigabytes physical RAM, then
- answer "4GB" here.
-
- If more than 4 Gigabytes is used then answer "64GB" here. This
- selection turns Intel PAE (Physical Address Extension) mode on.
- PAE implements 3-level paging on IA32 processors. PAE is fully
- supported by Linux, PAE mode is implemented on all recent Intel
- processors (Pentium Pro and better). NOTE: If you say "64GB" here,
- then the kernel will not boot on CPUs that don't support PAE!
-
- The actual amount of total physical memory will either be
- auto detected or can be forced by using a kernel command line option
- such as "mem=256M". (Try "man bootparam" or see the documentation of
- your boot loader (lilo or loadlin) about how to pass options to the
- kernel at boot time.)
-
- If unsure, say "off".
-
-config HIGHMEM4G
- bool "4GB"
- help
- Select this if you have a 32-bit processor and between 1 and 4
- gigabytes of physical RAM.
+ answer "Y" here.
-config HIGHMEM64G
- bool "64GB"
- depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
- select X86_PAE
- help
- Select this if you have a 32-bit processor and more than 4
- gigabytes of physical RAM.
-
-endchoice
+ If unsure, say N.
choice
prompt "Memory split" if EXPERT
@@ -1453,41 +1458,18 @@ config PAGE_OFFSET
depends on X86_32
config HIGHMEM
- def_bool y
- depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
+ def_bool HIGHMEM4G
config X86_PAE
bool "PAE (Physical Address Extension) Support"
- depends on X86_32 && !HIGHMEM4G
+ depends on X86_32 && X86_HAVE_PAE
select PHYS_ADDR_T_64BIT
- select SWIOTLB
help
PAE is required for NX support, and furthermore enables
larger swapspace support for non-overcommit purposes. It
has the cost of more pagetable lookup overhead, and also
consumes more pagetable space per process.
-config X86_5LEVEL
- bool "Enable 5-level page tables support"
- default y
- select DYNAMIC_MEMORY_LAYOUT
- select SPARSEMEM_VMEMMAP
- depends on X86_64
- help
- 5-level paging enables access to larger address space:
- upto 128 PiB of virtual address space and 4 PiB of
- physical address space.
-
- It will be supported by future Intel CPUs.
-
- A kernel with the option enabled can be booted on machines that
- support 4- or 5-level paging.
-
- See Documentation/x86/x86_64/5level-paging.rst for more
- information.
-
- Say N if unsure.
-
config X86_DIRECT_GBPAGES
def_bool y
depends on X86_64
@@ -1505,40 +1487,34 @@ config X86_CPA_STATISTICS
helps to determine the effectiveness of preserving large and huge
page mappings when mapping protections are changed.
+config X86_MEM_ENCRYPT
+ select ARCH_HAS_FORCE_DMA_UNENCRYPTED
+ select DYNAMIC_PHYSICAL_MASK
+ def_bool n
+
config AMD_MEM_ENCRYPT
bool "AMD Secure Memory Encryption (SME) support"
depends on X86_64 && CPU_SUP_AMD
+ depends on EFI_STUB
select DMA_COHERENT_POOL
- select DYNAMIC_PHYSICAL_MASK
select ARCH_USE_MEMREMAP_PROT
- select ARCH_HAS_FORCE_DMA_UNENCRYPTED
select INSTRUCTION_DECODER
- select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+ select ARCH_HAS_CC_PLATFORM
+ select X86_MEM_ENCRYPT
+ select UNACCEPTED_MEMORY
+ select CRYPTO_LIB_AESGCM
help
Say yes to enable support for the encryption of system memory.
This requires an AMD processor that supports Secure Memory
Encryption (SME).
-config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
- bool "Activate AMD Secure Memory Encryption (SME) by default"
- default y
- depends on AMD_MEM_ENCRYPT
- help
- Say yes to have system memory encrypted by default if running on
- an AMD processor that supports Secure Memory Encryption (SME).
-
- If set to Y, then the encryption of system memory can be
- deactivated with the mem_encrypt=off command line option.
-
- If set to N, then the encryption of system memory can be
- activated with the mem_encrypt=on command line option.
-
# Common NUMA Features
config NUMA
bool "NUMA Memory Allocation and Scheduler Support"
depends on SMP
- depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
- default y if X86_BIGSMP
+ depends on X86_64
+ select USE_PERCPU_NUMA_NODE_ID
+ select OF_NUMA if OF
help
Enable NUMA (Non-Uniform Memory Access) support.
@@ -1549,9 +1525,6 @@ config NUMA
For 64-bit this is recommended if the system is Intel Core i7
(or later), AMD Opteron, or EM64T NUMA.
- For 32-bit this is only needed if you boot a 32-bit
- kernel on a 64-bit NUMA platform.
-
Otherwise, you should say N.
config AMD_NUMA
@@ -1573,14 +1546,6 @@ config X86_64_ACPI_NUMA
help
Enable ACPI SRAT based node topology detection.
-config NUMA_EMU
- bool "NUMA emulation"
- depends on NUMA
- help
- Enable NUMA emulation. A flat machine will be split
- into virtual nodes when booted with "numa=fake=N", where N is the
- number of nodes. This is only useful for debugging.
-
config NODES_SHIFT
int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
range 1 10
@@ -1598,7 +1563,6 @@ config ARCH_FLATMEM_ENABLE
config ARCH_SPARSEMEM_ENABLE
def_bool y
- depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
select SPARSEMEM_STATIC if X86_32
select SPARSEMEM_VMEMMAP_ENABLE if X86_64
@@ -1607,11 +1571,11 @@ config ARCH_SPARSEMEM_DEFAULT
config ARCH_SELECT_MEMORY_MODEL
def_bool y
- depends on ARCH_SPARSEMEM_ENABLE
+ depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
config ARCH_MEMORY_PROBE
bool "Enable sysfs memory/probe interface"
- depends on X86_64 && MEMORY_HOTPLUG
+ depends on MEMORY_HOTPLUG
help
This option enables a sysfs memory/probe interface for testing.
See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
@@ -1644,15 +1608,6 @@ config X86_PMEM_LEGACY
Say Y if unsure.
-config HIGHPTE
- bool "Allocate 3rd-level pagetables from highmem"
- depends on HIGHMEM
- help
- The VM uses one page table entry for each page of physical memory.
- For systems with a lot of RAM, this can be wasteful of precious
- low memory. Setting this option will put user-space page table
- entries in high memory.
-
config X86_CHECK_BIOS_CORRUPTION
bool "Check for low memory corruption"
help
@@ -1743,7 +1698,7 @@ config MTRR
You can safely say Y even if your machine doesn't have MTRRs, you'll
just add about 9 KB to your kernel.
- See <file:Documentation/x86/mtrr.rst> for more information.
+ See <file:Documentation/arch/x86/mtrr.rst> for more information.
config MTRR_SANITIZER
def_bool y
@@ -1780,6 +1735,7 @@ config X86_PAT
def_bool y
prompt "x86 PAT support" if EXPERT
depends on MTRR
+ select ARCH_USES_PG_ARCH_2
help
Use PAT attributes to setup page level cache control.
@@ -1791,30 +1747,6 @@ config X86_PAT
If unsure, say Y.
-config ARCH_USES_PG_UNCACHED
- def_bool y
- depends on X86_PAT
-
-config ARCH_RANDOM
- def_bool y
- prompt "x86 architectural random number generator" if EXPERT
- help
- Enable the x86 architectural RDRAND instruction
- (Intel Bull Mountain technology) to generate random numbers.
- If supported, this is a high bandwidth, cryptographically
- secure hardware random number generator.
-
-config X86_SMAP
- def_bool y
- prompt "Supervisor Mode Access Prevention" if EXPERT
- help
- Supervisor Mode Access Prevention (SMAP) is a security
- feature in newer Intel processors. There is a small
- performance cost if this enabled and turned on; there is
- also a small increase in the kernel size if this is enabled.
-
- If unsure, say Y.
-
config X86_UMIP
def_bool y
prompt "User Mode Instruction Prevention" if EXPERT
@@ -1830,6 +1762,37 @@ config X86_UMIP
specific cases in protected and virtual-8086 modes. Emulated
results are dummy.
+config CC_HAS_IBT
+ # GCC >= 9 and binutils >= 2.29
+ # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
+ def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || CC_IS_CLANG) && \
+ $(as-instr,endbr64)
+
+config X86_CET
+ def_bool n
+ help
+ CET features configured (Shadow stack or IBT)
+
+config X86_KERNEL_IBT
+ prompt "Indirect Branch Tracking"
+ def_bool y
+ depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
+ select OBJTOOL
+ select X86_CET
+ help
+ Build the kernel with support for Indirect Branch Tracking, a
+ hardware support course-grain forward-edge Control Flow Integrity
+ protection. It enforces that all indirect calls must land on
+ an ENDBR instruction, as such, the compiler will instrument the
+ code with them to make this happen.
+
+ In addition to building the kernel with IBT, seal all functions that
+ are not indirect call targets, avoiding them ever becoming one.
+
+ This requires LTO like objtool runs and will slow down the build. It
+ does significantly reduce the number of ENDBR instructions in the
+ kernel image.
+
config X86_INTEL_MEMORY_PROTECTION_KEYS
prompt "Memory Protection Keys"
def_bool y
@@ -1846,6 +1809,10 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS
If unsure, say y.
+config ARCH_PKEY_BITS
+ int
+ default 4
+
choice
prompt "TSX enable mode"
depends on CPU_SUP_INTEL
@@ -1893,12 +1860,11 @@ endchoice
config X86_SGX
bool "Software Guard eXtensions (SGX)"
- depends on X86_64 && CPU_SUP_INTEL
- depends on CRYPTO=y
- depends on CRYPTO_SHA256=y
- select SRCU
+ depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
+ select CRYPTO_LIB_SHA256
select MMU_NOTIFIER
select NUMA_KEEP_MEMINFO if NUMA
+ select XARRAY_MULTI
help
Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
that can be used by applications to set aside private regions of code
@@ -1909,11 +1875,48 @@ config X86_SGX
If unsure, say N.
+config X86_USER_SHADOW_STACK
+ bool "X86 userspace shadow stack"
+ depends on AS_WRUSS
+ depends on X86_64
+ select ARCH_USES_HIGH_VMA_FLAGS
+ select ARCH_HAS_USER_SHADOW_STACK
+ select X86_CET
+ help
+ Shadow stack protection is a hardware feature that detects function
+ return address corruption. This helps mitigate ROP attacks.
+ Applications must be enabled to use it, and old userspace does not
+ get protection "for free".
+
+ CPUs supporting shadow stacks were first released in 2020.
+
+ See Documentation/arch/x86/shstk.rst for more information.
+
+ If unsure, say N.
+
+config INTEL_TDX_HOST
+ bool "Intel Trust Domain Extensions (TDX) host support"
+ depends on CPU_SUP_INTEL
+ depends on X86_64
+ depends on KVM_INTEL
+ depends on X86_X2APIC
+ select ARCH_KEEP_MEMBLOCK
+ depends on CONTIG_ALLOC
+ depends on X86_MCE
+ help
+ Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
+ host and certain physical attacks. This option enables necessary TDX
+ support in the host kernel to run confidential VMs.
+
+ If unsure, say N.
+
config EFI
bool "EFI runtime service support"
depends on ACPI
select UCS2_STRING
select EFI_RUNTIME_WRAPPERS
+ select ARCH_USE_MEMREMAP_PROT
+ select EFI_RUNTIME_MAP if KEXEC_CORE
help
This enables the kernel to use EFI runtime services that are
available (such as the EFI variable services).
@@ -1927,8 +1930,7 @@ config EFI
config EFI_STUB
bool "EFI stub support"
- depends on EFI && !X86_USE_3DNOW
- depends on $(cc-option,-mabi=ms) || X86_32
+ depends on EFI
select RELOCATABLE
help
This kernel feature allows a bzImage to be loaded directly
@@ -1936,104 +1938,89 @@ config EFI_STUB
See Documentation/admin-guide/efi-stub.rst for more information.
+config EFI_HANDOVER_PROTOCOL
+ bool "EFI handover protocol (DEPRECATED)"
+ depends on EFI_STUB
+ default y
+ help
+ Select this in order to include support for the deprecated EFI
+ handover protocol, which defines alternative entry points into the
+ EFI stub. This is a practice that has no basis in the UEFI
+ specification, and requires a priori knowledge on the part of the
+ bootloader about Linux/x86 specific ways of passing the command line
+ and initrd, and where in memory those assets may be loaded.
+
+ If in doubt, say Y. Even though the corresponding support is not
+ present in upstream GRUB or other bootloaders, most distros build
+ GRUB with numerous downstream patches applied, and may rely on the
+ handover protocol as as result.
+
config EFI_MIXED
bool "EFI mixed-mode support"
depends on EFI_STUB && X86_64
help
- Enabling this feature allows a 64-bit kernel to be booted
- on a 32-bit firmware, provided that your CPU supports 64-bit
- mode.
-
- Note that it is not possible to boot a mixed-mode enabled
- kernel via the EFI boot stub - a bootloader that supports
- the EFI handover protocol must be used.
+ Enabling this feature allows a 64-bit kernel to be booted
+ on a 32-bit firmware, provided that your CPU supports 64-bit
+ mode.
- If unsure, say N.
+ Note that it is not possible to boot a mixed-mode enabled
+ kernel via the EFI boot stub - a bootloader that supports
+ the EFI handover protocol must be used.
-source "kernel/Kconfig.hz"
+ If unsure, say N.
-config KEXEC
- bool "kexec system call"
- select KEXEC_CORE
+config EFI_RUNTIME_MAP
+ bool "Export EFI runtime maps to sysfs" if EXPERT
+ depends on EFI
help
- kexec is a system call that implements the ability to shutdown your
- current kernel, and to start another kernel. It is like a reboot
- but it is independent of the system firmware. And like a reboot
- you can start any kernel with it, not just Linux.
+ Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
+ That memory map is required by the 2nd kernel to set up EFI virtual
+ mappings after kexec, but can also be used for debugging purposes.
- The name comes from the similarity to the exec system call.
+ See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
- It is an ongoing process to be certain the hardware in a machine
- is properly shutdown, so do not be surprised if this code does not
- initially work for you. As of this writing the exact hardware
- interface is strongly in flux, so no good recommendation can be
- made.
+source "kernel/Kconfig.hz"
-config KEXEC_FILE
- bool "kexec file based system call"
- select KEXEC_CORE
- select BUILD_BIN2C
- depends on X86_64
- depends on CRYPTO=y
- depends on CRYPTO_SHA256=y
- help
- This is new version of kexec system call. This system call is
- file based and takes file descriptors as system call argument
- for kernel and initramfs as opposed to list of segments as
- accepted by previous system call.
+config ARCH_SUPPORTS_KEXEC
+ def_bool y
-config ARCH_HAS_KEXEC_PURGATORY
- def_bool KEXEC_FILE
+config ARCH_SUPPORTS_KEXEC_FILE
+ def_bool X86_64
-config KEXEC_SIG
- bool "Verify kernel signature during kexec_file_load() syscall"
+config ARCH_SELECTS_KEXEC_FILE
+ def_bool y
depends on KEXEC_FILE
- help
+ select HAVE_IMA_KEXEC if IMA
- This option makes the kexec_file_load() syscall check for a valid
- signature of the kernel image. The image can still be loaded without
- a valid signature unless you also enable KEXEC_SIG_FORCE, though if
- there's a signature that we can check, then it must be valid.
+config ARCH_SUPPORTS_KEXEC_PURGATORY
+ def_bool y
- In addition to this option, you need to enable signature
- verification for the corresponding kernel image type being
- loaded in order for this to work.
+config ARCH_SUPPORTS_KEXEC_SIG
+ def_bool y
-config KEXEC_SIG_FORCE
- bool "Require a valid signature in kexec_file_load() syscall"
- depends on KEXEC_SIG
- help
- This option makes kernel signature verification mandatory for
- the kexec_file_load() syscall.
+config ARCH_SUPPORTS_KEXEC_SIG_FORCE
+ def_bool y
-config KEXEC_BZIMAGE_VERIFY_SIG
- bool "Enable bzImage signature verification support"
- depends on KEXEC_SIG
- depends on SIGNED_PE_FILE_VERIFICATION
- select SYSTEM_TRUSTED_KEYRING
- help
- Enable bzImage signature verification support.
+config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
+ def_bool y
-config CRASH_DUMP
- bool "kernel crash dumps"
- depends on X86_64 || (X86_32 && HIGHMEM)
- help
- Generate crash dump after being started by kexec.
- This should be normally only set in special crash dump kernels
- which are loaded in the main kernel with kexec-tools into
- a specially reserved region and then later executed after
- a crash by kdump/kexec. The crash dump kernel must be compiled
- to a memory address not used by the main kernel or BIOS using
- PHYSICAL_START, or it must be built as a relocatable image
- (CONFIG_RELOCATABLE=y).
- For more details see Documentation/admin-guide/kdump/kdump.rst
+config ARCH_SUPPORTS_KEXEC_JUMP
+ def_bool y
-config KEXEC_JUMP
- bool "kexec jump"
- depends on KEXEC && HIBERNATION
- help
- Jump between original kernel and kexeced kernel and invoke
- code in physical address mode via KEXEC
+config ARCH_SUPPORTS_KEXEC_HANDOVER
+ def_bool X86_64
+
+config ARCH_SUPPORTS_CRASH_DUMP
+ def_bool X86_64 || (X86_32 && HIGHMEM)
+
+config ARCH_DEFAULT_CRASH_DUMP
+ def_bool y
+
+config ARCH_SUPPORTS_CRASH_HOTPLUG
+ def_bool y
+
+config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+ def_bool CRASH_RESERVE
config PHYSICAL_START
hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
@@ -2041,11 +2028,11 @@ config PHYSICAL_START
help
This gives the physical address where the kernel is loaded.
- If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
- bzImage will decompress itself to above physical address and
- run from there. Otherwise, bzImage will run from the address where
- it has been loaded by the boot loader and will ignore above physical
- address.
+ If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage
+ will decompress itself to above physical address and run from there.
+ Otherwise, bzImage will run from the address where it has been loaded
+ by the boot loader. The only exception is if it is loaded below the
+ above physical address, in which case it will relocate itself there.
In normal kdump cases one does not have to set/change this option
as now bzImage can be compiled as a completely relocatable image
@@ -2132,6 +2119,7 @@ config RANDOMIZE_BASE
config X86_NEED_RELOCS
def_bool y
depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
+ select ARCH_VMLINUX_NEEDS_RELOCS
config PHYSICAL_ALIGN
hex "Alignment value to which kernel should be aligned"
@@ -2160,29 +2148,22 @@ config PHYSICAL_ALIGN
Don't change this unless you know what you are doing.
-config DYNAMIC_MEMORY_LAYOUT
- bool
- help
- This option makes base addresses of vmalloc and vmemmap as well as
- __PAGE_OFFSET movable during boot.
-
config RANDOMIZE_MEMORY
bool "Randomize the kernel memory sections"
depends on X86_64
depends on RANDOMIZE_BASE
- select DYNAMIC_MEMORY_LAYOUT
default RANDOMIZE_BASE
help
- Randomizes the base virtual address of kernel memory sections
- (physical memory mapping, vmalloc & vmemmap). This security feature
- makes exploits relying on predictable memory locations less reliable.
+ Randomizes the base virtual address of kernel memory sections
+ (physical memory mapping, vmalloc & vmemmap). This security feature
+ makes exploits relying on predictable memory locations less reliable.
- The order of allocations remains unchanged. Entropy is generated in
- the same way as RANDOMIZE_BASE. Current implementation in the optimal
- configuration have in average 30,000 different possible virtual
- addresses for each memory section.
+ The order of allocations remains unchanged. Entropy is generated in
+ the same way as RANDOMIZE_BASE. Current implementation in the optimal
+ configuration have in average 30,000 different possible virtual
+ addresses for each memory section.
- If unsure, say Y.
+ If unsure, say Y.
config RANDOMIZE_MEMORY_PHYSICAL_PADDING
hex "Physical memory mapping padding" if EXPERT
@@ -2192,63 +2173,32 @@ config RANDOMIZE_MEMORY_PHYSICAL_PADDING
range 0x1 0x40 if MEMORY_HOTPLUG
range 0x0 0x40
help
- Define the padding in terabytes added to the existing physical
- memory size during kernel memory randomization. It is useful
- for memory hotplug support but reduces the entropy available for
- address randomization.
+ Define the padding in terabytes added to the existing physical
+ memory size during kernel memory randomization. It is useful
+ for memory hotplug support but reduces the entropy available for
+ address randomization.
- If unsure, leave at the default value.
+ If unsure, leave at the default value.
-config HOTPLUG_CPU
- def_bool y
- depends on SMP
-
-config BOOTPARAM_HOTPLUG_CPU0
- bool "Set default setting of cpu0_hotpluggable"
- depends on HOTPLUG_CPU
- help
- Set whether default state of cpu0_hotpluggable is on or off.
-
- Say Y here to enable CPU0 hotplug by default. If this switch
- is turned on, there is no need to give cpu0_hotplug kernel
- parameter and the CPU0 hotplug feature is enabled by default.
-
- Please note: there are two known CPU0 dependencies if you want
- to enable the CPU0 hotplug feature either by this switch or by
- cpu0_hotplug kernel parameter.
-
- First, resume from hibernate or suspend always starts from CPU0.
- So hibernate and suspend are prevented if CPU0 is offline.
-
- Second dependency is PIC interrupts always go to CPU0. CPU0 can not
- offline if any interrupt can not migrate out of CPU0. There may
- be other CPU0 dependencies.
-
- Please make sure the dependencies are under your control before
- you enable this feature.
-
- Say N if you don't want to enable CPU0 hotplug feature by default.
- You still can enable the CPU0 hotplug feature at boot by kernel
- parameter cpu0_hotplug.
-
-config DEBUG_HOTPLUG_CPU0
- def_bool n
- prompt "Debug CPU0 hotplug"
- depends on HOTPLUG_CPU
+config ADDRESS_MASKING
+ bool "Linear Address Masking support"
+ depends on X86_64
+ depends on COMPILE_TEST || !CPU_MITIGATIONS # wait for LASS
help
- Enabling this option offlines CPU0 (if CPU0 can be offlined) as
- soon as possible and boots up userspace with CPU0 offlined. User
- can online CPU0 back after boot time.
+ Linear Address Masking (LAM) modifies the checking that is applied
+ to 64-bit linear addresses, allowing software to use of the
+ untranslated address bits for metadata.
- To debug CPU0 hotplug, you need to enable CPU0 offline/online
- feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
- compilation or giving cpu0_hotplug kernel parameter at boot.
+ The capability can be used for efficient address sanitizers (ASAN)
+ implementation and for optimizations in JITs.
- If unsure, say N.
+config HOTPLUG_CPU
+ def_bool y
+ depends on SMP
config COMPAT_VDSO
def_bool n
- prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
+ prompt "Workaround for glibc 2.3.2 / 2.3.3 (released in year 2003/2004)"
depends on COMPAT_32
help
Certain buggy versions of glibc will crash if they are
@@ -2282,7 +2232,9 @@ choice
it can be used to assist security vulnerability exploitation.
This setting can be changed at boot time via the kernel command
- line parameter vsyscall=[emulate|xonly|none].
+ line parameter vsyscall=[emulate|xonly|none]. Emulate mode
+ is deprecated and can only be enabled using the kernel command
+ line.
On a system with recent enough glibc (2.14 or newer) and no
static binaries, you can say None without a performance penalty
@@ -2290,20 +2242,6 @@ choice
If unsure, select "Emulate execution only".
- config LEGACY_VSYSCALL_EMULATE
- bool "Full emulation"
- help
- The kernel traps and emulates calls into the fixed vsyscall
- address mapping. This makes the mapping non-executable, but
- it still contains readable known contents, which could be
- used in certain rare security vulnerability exploits. This
- configuration is recommended when using legacy userspace
- that still uses vsyscalls along with legacy binary
- instrumentation tools that require code to be readable.
-
- An example of this type of legacy userspace is running
- Pin on an old binary that still uses vsyscalls.
-
config LEGACY_VSYSCALL_XONLY
bool "Emulate execution only"
help
@@ -2385,20 +2323,403 @@ config MODIFY_LDT_SYSCALL
Saying 'N' here may make sense for embedded or server kernels.
+config STRICT_SIGALTSTACK_SIZE
+ bool "Enforce strict size checking for sigaltstack"
+ depends on DYNAMIC_SIGFRAME
+ help
+ For historical reasons MINSIGSTKSZ is a constant which became
+ already too small with AVX512 support. Add a mechanism to
+ enforce strict checking of the sigaltstack size against the
+ real size of the FPU frame. This option enables the check
+ by default. It can also be controlled via the kernel command
+ line option 'strict_sas_size' independent of this config
+ switch. Enabling it might break existing applications which
+ allocate a too small sigaltstack but 'work' because they
+ never get a signal delivered.
+
+ Say 'N' unless you want to really enforce this check.
+
+config CFI_AUTO_DEFAULT
+ bool "Attempt to use FineIBT by default at boot time"
+ depends on FINEIBT
+ depends on !RUST || RUSTC_VERSION >= 108800
+ default y
+ help
+ Attempt to use FineIBT by default at boot time. If enabled,
+ this is the same as booting with "cfi=auto". If disabled,
+ this is the same as booting with "cfi=kcfi".
+
source "kernel/livepatch/Kconfig"
+config X86_BUS_LOCK_DETECT
+ bool "Split Lock Detect and Bus Lock Detect support"
+ depends on CPU_SUP_INTEL || CPU_SUP_AMD
+ default y
+ help
+ Enable Split Lock Detect and Bus Lock Detect functionalities.
+ See <file:Documentation/arch/x86/buslock.rst> for more information.
+
endmenu
-config ARCH_HAS_ADD_PAGES
+config CC_HAS_NAMED_AS
+ def_bool $(success,echo 'int __seg_fs fs; int __seg_gs gs;' | $(CC) -x c - -S -o /dev/null)
+ depends on CC_IS_GCC
+
+#
+# -fsanitize=kernel-address (KASAN) and -fsanitize=thread (KCSAN)
+# are incompatible with named address spaces with GCC < 13.3
+# (see GCC PR sanitizer/111736 and also PR sanitizer/115172).
+#
+
+config CC_HAS_NAMED_AS_FIXED_SANITIZERS
+ def_bool y
+ depends on !(KASAN || KCSAN) || GCC_VERSION >= 130300
+ depends on !(UBSAN_BOOL && KASAN) || GCC_VERSION >= 140200
+
+config USE_X86_SEG_SUPPORT
+ def_bool CC_HAS_NAMED_AS
+ depends on CC_HAS_NAMED_AS_FIXED_SANITIZERS
+
+config CC_HAS_SLS
+ def_bool $(cc-option,-mharden-sls=all)
+
+config CC_HAS_RETURN_THUNK
+ def_bool $(cc-option,-mfunction-return=thunk-extern)
+
+config CC_HAS_ENTRY_PADDING
+ def_bool $(cc-option,-fpatchable-function-entry=16,16)
+
+config CC_HAS_KCFI_ARITY
+ def_bool $(cc-option,-fsanitize=kcfi -fsanitize-kcfi-arity)
+ depends on CC_IS_CLANG && !RUST
+
+config FUNCTION_PADDING_CFI
+ int
+ default 59 if FUNCTION_ALIGNMENT_64B
+ default 27 if FUNCTION_ALIGNMENT_32B
+ default 11 if FUNCTION_ALIGNMENT_16B
+ default 3 if FUNCTION_ALIGNMENT_8B
+ default 0
+
+# Basically: FUNCTION_ALIGNMENT - 5*CFI
+# except Kconfig can't do arithmetic :/
+config FUNCTION_PADDING_BYTES
+ int
+ default FUNCTION_PADDING_CFI if CFI
+ default FUNCTION_ALIGNMENT
+
+config CALL_PADDING
+ def_bool n
+ depends on CC_HAS_ENTRY_PADDING && OBJTOOL
+ select FUNCTION_ALIGNMENT_16B
+
+config FINEIBT
def_bool y
- depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
+ depends on X86_KERNEL_IBT && CFI && MITIGATION_RETPOLINE
+ select CALL_PADDING
-config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
+config FINEIBT_BHI
def_bool y
+ depends on FINEIBT && CC_HAS_KCFI_ARITY
-config USE_PERCPU_NUMA_NODE_ID
+config HAVE_CALL_THUNKS
def_bool y
- depends on NUMA
+ depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL
+
+config CALL_THUNKS
+ def_bool n
+ select CALL_PADDING
+
+config PREFIX_SYMBOLS
+ def_bool y
+ depends on CALL_PADDING && !CFI
+
+menuconfig CPU_MITIGATIONS
+ bool "Mitigations for CPU vulnerabilities"
+ default y
+ help
+ Say Y here to enable options which enable mitigations for hardware
+ vulnerabilities (usually related to speculative execution).
+ Mitigations can be disabled or restricted to SMT systems at runtime
+ via the "mitigations" kernel parameter.
+
+ If you say N, all mitigations will be disabled. This CANNOT be
+ overridden at runtime.
+
+ Say 'Y', unless you really know what you are doing.
+
+if CPU_MITIGATIONS
+
+config MITIGATION_PAGE_TABLE_ISOLATION
+ bool "Remove the kernel mapping in user mode"
+ default y
+ depends on (X86_64 || X86_PAE)
+ help
+ This feature reduces the number of hardware side channels by
+ ensuring that the majority of kernel addresses are not mapped
+ into userspace.
+
+ See Documentation/arch/x86/pti.rst for more details.
+
+config MITIGATION_RETPOLINE
+ bool "Avoid speculative indirect branches in kernel"
+ select OBJTOOL if HAVE_OBJTOOL
+ default y
+ help
+ Compile kernel with the retpoline compiler options to guard against
+ kernel-to-user data leaks by avoiding speculative indirect
+ branches. Requires a compiler with -mindirect-branch=thunk-extern
+ support for full protection. The kernel may run slower.
+
+config MITIGATION_RETHUNK
+ bool "Enable return-thunks"
+ depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK
+ select OBJTOOL if HAVE_OBJTOOL
+ default y if X86_64
+ help
+ Compile the kernel with the return-thunks compiler option to guard
+ against kernel-to-user data leaks by avoiding return speculation.
+ Requires a compiler with -mfunction-return=thunk-extern
+ support for full protection. The kernel may run slower.
+
+config MITIGATION_UNRET_ENTRY
+ bool "Enable UNRET on kernel entry"
+ depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64
+ default y
+ help
+ Compile the kernel with support for the retbleed=unret mitigation.
+
+config MITIGATION_CALL_DEPTH_TRACKING
+ bool "Mitigate RSB underflow with call depth tracking"
+ depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
+ select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
+ select CALL_THUNKS
+ default y
+ help
+ Compile the kernel with call depth tracking to mitigate the Intel
+ SKL Return-Stack-Buffer (RSB) underflow issue. The mitigation is off
+ by default and needs to be enabled on the kernel command line via the
+ retbleed=stuff option. For non-affected systems the overhead of this
+ option is marginal as the call depth tracking is using run-time
+ generated call thunks in a compiler generated padding area and call
+ patching. This increases text size by ~5%. For non affected systems
+ this space is unused. On affected SKL systems this results in a
+ significant performance gain over the IBRS mitigation.
+
+config CALL_THUNKS_DEBUG
+ bool "Enable call thunks and call depth tracking debugging"
+ depends on MITIGATION_CALL_DEPTH_TRACKING
+ select FUNCTION_ALIGNMENT_32B
+ default n
+ help
+ Enable call/ret counters for imbalance detection and build in
+ a noisy dmesg about callthunks generation and call patching for
+ trouble shooting. The debug prints need to be enabled on the
+ kernel command line with 'debug-callthunks'.
+ Only enable this when you are debugging call thunks as this
+ creates a noticeable runtime overhead. If unsure say N.
+
+config MITIGATION_IBPB_ENTRY
+ bool "Enable IBPB on kernel entry"
+ depends on CPU_SUP_AMD && X86_64
+ default y
+ help
+ Compile the kernel with support for the retbleed=ibpb and
+ spec_rstack_overflow={ibpb,ibpb-vmexit} mitigations.
+
+config MITIGATION_IBRS_ENTRY
+ bool "Enable IBRS on kernel entry"
+ depends on CPU_SUP_INTEL && X86_64
+ default y
+ help
+ Compile the kernel with support for the spectre_v2=ibrs mitigation.
+ This mitigates both spectre_v2 and retbleed at great cost to
+ performance.
+
+config MITIGATION_SRSO
+ bool "Mitigate speculative RAS overflow on AMD"
+ depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK
+ default y
+ help
+ Enable the SRSO mitigation needed on AMD Zen1-4 machines.
+
+config MITIGATION_SLS
+ bool "Mitigate Straight-Line-Speculation"
+ depends on CC_HAS_SLS && X86_64
+ select OBJTOOL if HAVE_OBJTOOL
+ default n
+ help
+ Compile the kernel with straight-line-speculation options to guard
+ against straight line speculation. The kernel image might be slightly
+ larger.
+
+config MITIGATION_GDS
+ bool "Mitigate Gather Data Sampling"
+ depends on CPU_SUP_INTEL
+ default y
+ help
+ Enable mitigation for Gather Data Sampling (GDS). GDS is a hardware
+ vulnerability which allows unprivileged speculative access to data
+ which was previously stored in vector registers. The attacker uses gather
+ instructions to infer the stale vector register data.
+
+config MITIGATION_RFDS
+ bool "RFDS Mitigation"
+ depends on CPU_SUP_INTEL
+ default y
+ help
+ Enable mitigation for Register File Data Sampling (RFDS) by default.
+ RFDS is a hardware vulnerability which affects Intel Atom CPUs. It
+ allows unprivileged speculative access to stale data previously
+ stored in floating point, vector and integer registers.
+ See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>
+
+config MITIGATION_SPECTRE_BHI
+ bool "Mitigate Spectre-BHB (Branch History Injection)"
+ depends on CPU_SUP_INTEL
+ default y
+ help
+ Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
+ where the branch history buffer is poisoned to speculatively steer
+ indirect branches.
+ See <file:Documentation/admin-guide/hw-vuln/spectre.rst>
+
+config MITIGATION_MDS
+ bool "Mitigate Microarchitectural Data Sampling (MDS) hardware bug"
+ depends on CPU_SUP_INTEL
+ default y
+ help
+ Enable mitigation for Microarchitectural Data Sampling (MDS). MDS is
+ a hardware vulnerability which allows unprivileged speculative access
+ to data which is available in various CPU internal buffers.
+ See also <file:Documentation/admin-guide/hw-vuln/mds.rst>
+
+config MITIGATION_TAA
+ bool "Mitigate TSX Asynchronous Abort (TAA) hardware bug"
+ depends on CPU_SUP_INTEL
+ default y
+ help
+ Enable mitigation for TSX Asynchronous Abort (TAA). TAA is a hardware
+ vulnerability that allows unprivileged speculative access to data
+ which is available in various CPU internal buffers by using
+ asynchronous aborts within an Intel TSX transactional region.
+ See also <file:Documentation/admin-guide/hw-vuln/tsx_async_abort.rst>
+
+config MITIGATION_MMIO_STALE_DATA
+ bool "Mitigate MMIO Stale Data hardware bug"
+ depends on CPU_SUP_INTEL
+ default y
+ help
+ Enable mitigation for MMIO Stale Data hardware bugs. Processor MMIO
+ Stale Data Vulnerabilities are a class of memory-mapped I/O (MMIO)
+ vulnerabilities that can expose data. The vulnerabilities require the
+ attacker to have access to MMIO.
+ See also
+ <file:Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst>
+
+config MITIGATION_L1TF
+ bool "Mitigate L1 Terminal Fault (L1TF) hardware bug"
+ depends on CPU_SUP_INTEL
+ default y
+ help
+ Mitigate L1 Terminal Fault (L1TF) hardware bug. L1 Terminal Fault is a
+ hardware vulnerability which allows unprivileged speculative access to data
+ available in the Level 1 Data Cache.
+ See <file:Documentation/admin-guide/hw-vuln/l1tf.rst
+
+config MITIGATION_RETBLEED
+ bool "Mitigate RETBleed hardware bug"
+ depends on (CPU_SUP_INTEL && MITIGATION_SPECTRE_V2) || MITIGATION_UNRET_ENTRY || MITIGATION_IBPB_ENTRY
+ default y
+ help
+ Enable mitigation for RETBleed (Arbitrary Speculative Code Execution
+ with Return Instructions) vulnerability. RETBleed is a speculative
+ execution attack which takes advantage of microarchitectural behavior
+ in many modern microprocessors, similar to Spectre v2. An
+ unprivileged attacker can use these flaws to bypass conventional
+ memory security restrictions to gain read access to privileged memory
+ that would otherwise be inaccessible.
+
+config MITIGATION_SPECTRE_V1
+ bool "Mitigate SPECTRE V1 hardware bug"
+ default y
+ help
+ Enable mitigation for Spectre V1 (Bounds Check Bypass). Spectre V1 is a
+ class of side channel attacks that takes advantage of speculative
+ execution that bypasses conditional branch instructions used for
+ memory access bounds check.
+ See also <file:Documentation/admin-guide/hw-vuln/spectre.rst>
+
+config MITIGATION_SPECTRE_V2
+ bool "Mitigate SPECTRE V2 hardware bug"
+ default y
+ help
+ Enable mitigation for Spectre V2 (Branch Target Injection). Spectre
+ V2 is a class of side channel attacks that takes advantage of
+ indirect branch predictors inside the processor. In Spectre variant 2
+ attacks, the attacker can steer speculative indirect branches in the
+ victim to gadget code by poisoning the branch target buffer of a CPU
+ used for predicting indirect branch addresses.
+ See also <file:Documentation/admin-guide/hw-vuln/spectre.rst>
+
+config MITIGATION_SRBDS
+ bool "Mitigate Special Register Buffer Data Sampling (SRBDS) hardware bug"
+ depends on CPU_SUP_INTEL
+ default y
+ help
+ Enable mitigation for Special Register Buffer Data Sampling (SRBDS).
+ SRBDS is a hardware vulnerability that allows Microarchitectural Data
+ Sampling (MDS) techniques to infer values returned from special
+ register accesses. An unprivileged user can extract values returned
+ from RDRAND and RDSEED executed on another core or sibling thread
+ using MDS techniques.
+ See also
+ <file:Documentation/admin-guide/hw-vuln/special-register-buffer-data-sampling.rst>
+
+config MITIGATION_SSB
+ bool "Mitigate Speculative Store Bypass (SSB) hardware bug"
+ default y
+ help
+ Enable mitigation for Speculative Store Bypass (SSB). SSB is a
+ hardware security vulnerability and its exploitation takes advantage
+ of speculative execution in a similar way to the Meltdown and Spectre
+ security vulnerabilities.
+
+config MITIGATION_ITS
+ bool "Enable Indirect Target Selection mitigation"
+ depends on CPU_SUP_INTEL && X86_64
+ depends on MITIGATION_RETPOLINE && MITIGATION_RETHUNK
+ select EXECMEM
+ default y
+ help
+ Enable Indirect Target Selection (ITS) mitigation. ITS is a bug in
+ BPU on some Intel CPUs that may allow Spectre V2 style attacks. If
+ disabled, mitigation cannot be enabled via cmdline.
+ See <file:Documentation/admin-guide/hw-vuln/indirect-target-selection.rst>
+
+config MITIGATION_TSA
+ bool "Mitigate Transient Scheduler Attacks"
+ depends on CPU_SUP_AMD
+ default y
+ help
+ Enable mitigation for Transient Scheduler Attacks. TSA is a hardware
+ security vulnerability on AMD CPUs which can lead to forwarding of
+ invalid info to subsequent instructions and thus can affect their
+ timing and thereby cause a leakage.
+
+config MITIGATION_VMSCAPE
+ bool "Mitigate VMSCAPE"
+ depends on KVM
+ default y
+ help
+ Enable mitigation for VMSCAPE attacks. VMSCAPE is a hardware security
+ vulnerability on Intel and AMD CPUs that may allow a guest to do
+ Spectre v2 style attacks on userspace hypervisor.
+endif
+
+config ARCH_HAS_ADD_PAGES
+ def_bool y
+ depends on ARCH_ENABLE_MEMORY_HOTPLUG
menu "Power management and ACPI options"
@@ -2456,7 +2777,7 @@ menuconfig APM
1) make sure that you have enough swap space and that it is
enabled.
- 2) pass the "no-hlt" option to the kernel
+ 2) pass the "idle=poll" option to the kernel
3) switch on floating point emulation in the kernel and pass
the "no387" option to the kernel
4) pass the "floppy=nodma" option to the kernel
@@ -2544,7 +2865,6 @@ source "drivers/idle/Kconfig"
endmenu
-
menu "Bus options (PCI etc.)"
choice
@@ -2598,6 +2918,19 @@ config PCI_MMCONFIG
default y
depends on PCI && (ACPI || JAILHOUSE_GUEST)
depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
+ help
+ Add support for accessing the PCI configuration space as a memory
+ mapped area. It is the recommended method if the system supports
+ this (it must have PCI Express and ACPI for it to be available).
+
+ In the unlikely case that enabling this configuration option causes
+ problems, the mechanism can be switched off with the 'pci=nommconf'
+ command line parameter.
+
+ Say N only if you are sure that your platform does not support this
+ access method or you have problems caused by it.
+
+ Say Y otherwise.
config PCI_OLPC
def_bool y
@@ -2606,20 +2939,27 @@ config PCI_OLPC
config PCI_XEN
def_bool y
depends on PCI && XEN
- select SWIOTLB_XEN
config MMCONF_FAM10H
def_bool y
depends on X86_64 && PCI_MMCONFIG && ACPI
config PCI_CNB20LE_QUIRK
- bool "Read CNB20LE Host Bridge Windows" if EXPERT
- depends on PCI
+ bool "Read PCI host bridge windows from the CNB20LE chipset" if EXPERT
+ depends on X86_32 && PCI
help
Read the PCI windows out of the CNB20LE host bridge. This allows
PCI hotplug to work on systems with the CNB20LE chipset which do
not have ACPI.
+ The ServerWorks (later Broadcom) CNB20LE was a chipset designed
+ most probably only for Pentium III.
+
+ To find out if you have such a chipset, search for a PCI device with
+ 1166:0009 PCI IDs, for example by executing
+ lspci -nn | grep '1166:0009'
+ The code is inactive if there is none.
+
There's no public spec for this chipset, and this functionality
is known to be incomplete.
@@ -2725,9 +3065,13 @@ config OLPC_XO15_SCI
- AC adapter status updates
- Battery status updates
+config GEODE_COMMON
+ bool
+
config ALIX
bool "PCEngines ALIX System Support (LED setup)"
select GPIOLIB
+ select GEODE_COMMON
help
This option enables system support for the PCEngines ALIX.
At present this just sets up LEDs for GPIO control on
@@ -2742,12 +3086,14 @@ config ALIX
config NET5501
bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
select GPIOLIB
+ select GEODE_COMMON
help
This option enables system support for the Soekris Engineering net5501.
config GEOS
bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
select GPIOLIB
+ select GEODE_COMMON
depends on DMI
help
This option enables system support for the Traverse Technologies GEOS.
@@ -2765,37 +3111,14 @@ endif # X86_32
config AMD_NB
def_bool y
- depends on CPU_SUP_AMD && PCI
-
-config X86_SYSFB
- bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
- help
- Firmwares often provide initial graphics framebuffers so the BIOS,
- bootloader or kernel can show basic video-output during boot for
- user-guidance and debugging. Historically, x86 used the VESA BIOS
- Extensions and EFI-framebuffers for this, which are mostly limited
- to x86.
- This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
- framebuffers so the new generic system-framebuffer drivers can be
- used on x86. If the framebuffer is not compatible with the generic
- modes, it is advertised as fallback platform framebuffer so legacy
- drivers like efifb, vesafb and uvesafb can pick it up.
- If this option is not selected, all system framebuffers are always
- marked as fallback platform framebuffers as usual.
-
- Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
- not be able to pick up generic system framebuffers if this option
- is selected. You are highly encouraged to enable simplefb as
- replacement if you select this option. simplefb can correctly deal
- with generic system framebuffers. But you should still keep vesafb
- and others enabled as fallback if a system framebuffer is
- incompatible with simplefb.
+ depends on AMD_NODE
- If unsure, say Y.
+config AMD_NODE
+ def_bool y
+ depends on CPU_SUP_AMD && PCI
endmenu
-
menu "Binary Emulations"
config IA32_EMULATION
@@ -2809,26 +3132,29 @@ config IA32_EMULATION
64-bit kernel. You should likely turn this on, unless you're
100% sure that you don't have any 32-bit programs left.
-config IA32_AOUT
- tristate "IA32 a.out support"
+config IA32_EMULATION_DEFAULT_DISABLED
+ bool "IA32 emulation disabled by default"
+ default n
depends on IA32_EMULATION
- depends on BROKEN
help
- Support old a.out binaries in the 32bit emulation.
+ Make IA32 emulation disabled by default. This prevents loading 32-bit
+ processes and access to 32-bit syscalls. If unsure, leave it to its
+ default value.
-config X86_X32
+config X86_X32_ABI
bool "x32 ABI for 64-bit mode"
depends on X86_64
+ # llvm-objcopy does not convert x86_64 .note.gnu.property or
+ # compressed debug sections to x86_x32 properly:
+ # https://github.com/ClangBuiltLinux/linux/issues/514
+ # https://github.com/ClangBuiltLinux/linux/issues/1141
+ depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
help
Include code to run binaries for the x32 native 32-bit ABI
for 64-bit processors. An x32 process gets access to the
full 64-bit register file and wide data path while leaving
pointers at 32 bits for smaller memory footprint.
- You will need a recent binutils (2.22 or later) with
- elf32_x86_64 support enabled to compile a kernel with this
- option set.
-
config COMPAT_32
def_bool y
depends on IA32_EMULATION || X86_32
@@ -2837,26 +3163,20 @@ config COMPAT_32
config COMPAT
def_bool y
- depends on IA32_EMULATION || X86_X32
+ depends on IA32_EMULATION || X86_X32_ABI
-if COMPAT
config COMPAT_FOR_U64_ALIGNMENT
def_bool y
-
-config SYSVIPC_COMPAT
- def_bool y
- depends on SYSVIPC
-endif
+ depends on COMPAT
endmenu
-
config HAVE_ATOMIC_IOMAP
def_bool y
depends on X86_32
-source "drivers/firmware/Kconfig"
-
source "arch/x86/kvm/Kconfig"
+source "arch/x86/Kconfig.cpufeatures"
+
source "arch/x86/Kconfig.assembler"