Commit 3d37d939 authored by H. Peter Anvin (Intel)'s avatar H. Peter Anvin (Intel) Committed by Ingo Molnar
Browse files

x86/cpufeatures: Add {REQUIRED,DISABLED} feature configs 



Required and disabled feature masks completely rely on build configs,
i.e., once a build config is fixed, so are the feature masks.

To prepare for auto-generating the <asm/cpufeaturemasks.h> header
with required and disabled feature masks based on a build config,
add feature Kconfig items:

  - X86_REQUIRED_FEATURE_x
  - X86_DISABLED_FEATURE_x

each of which may be set to "y" if and only if its preconditions from
current build config are met.

Signed-off-by: default avatarH. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: default avatarXin Li (Intel) <xin@zytor.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250228082338.73859-3-xin@zytor.com
parent f666c920

arch/x86/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -3130,4 +3130,6 @@ config HAVE_ATOMIC_IOMAP 


source "arch/x86/kvm/Kconfig"



source "arch/x86/Kconfig.cpufeatures"



source "arch/x86/Kconfig.assembler"

arch/x86/Kconfig.cpufeatures

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+201 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

#

# x86 feature bits (see arch/x86/include/asm/cpufeatures.h) that are

# either REQUIRED to be enabled, or DISABLED (always ignored) for this

# particular compile-time configuration.  The tests for these features

# are turned into compile-time constants via the generated

# <asm/cpufeaturemasks.h>.

#

# The naming of these variables *must* match asm/cpufeatures.h, e.g.,

#     X86_FEATURE_ALWAYS <==> X86_REQUIRED_FEATURE_ALWAYS

#     X86_FEATURE_FRED   <==> X86_DISABLED_FEATURE_FRED

#

# And these REQUIRED and DISABLED config options are manipulated in an

# AWK script as the following example:

#

#                          +----------------------+

#                          |    X86_FRED = y ?    |

#                          +----------------------+

#                              /             \

#                           Y /               \ N

#  +-------------------------------------+   +-------------------------------+

#  | X86_DISABLED_FEATURE_FRED undefined |   | X86_DISABLED_FEATURE_FRED = y |

#  +-------------------------------------+   +-------------------------------+

#                                                        |

#                                                        |

#     +-------------------------------------------+      |

#     | X86_FEATURE_FRED: feature word 12, bit 17 | ---->|

#     +-------------------------------------------+      |

#                                                        |

#                                                        |

#                                     +-------------------------------+

#                                     | set bit 17 of DISABLED_MASK12 |

#                                     +-------------------------------+

#



config X86_REQUIRED_FEATURE_ALWAYS

	def_bool y



config X86_REQUIRED_FEATURE_NOPL

	def_bool y

	depends on X86_64 || X86_P6_NOP



config X86_REQUIRED_FEATURE_CX8

	def_bool y

	depends on X86_CX8



# this should be set for all -march=.. options where the compiler

# generates cmov.

config X86_REQUIRED_FEATURE_CMOV

	def_bool y

	depends on X86_CMOV



# this should be set for all -march= options where the compiler

# generates movbe.

config X86_REQUIRED_FEATURE_MOVBE

	def_bool y

	depends on MATOM



config X86_REQUIRED_FEATURE_CPUID

	def_bool y

	depends on X86_64



config X86_REQUIRED_FEATURE_UP

	def_bool y

	depends on !SMP



config X86_REQUIRED_FEATURE_FPU

	def_bool y

	depends on !MATH_EMULATION



config X86_REQUIRED_FEATURE_PAE

	def_bool y

	depends on X86_64 || X86_PAE



config X86_REQUIRED_FEATURE_PSE

	def_bool y

	depends on X86_64 && !PARAVIRT_XXL



config X86_REQUIRED_FEATURE_PGE

	def_bool y

	depends on X86_64 && !PARAVIRT_XXL



config X86_REQUIRED_FEATURE_MSR

	def_bool y

	depends on X86_64



config X86_REQUIRED_FEATURE_FXSR

	def_bool y

	depends on X86_64



config X86_REQUIRED_FEATURE_XMM

	def_bool y

	depends on X86_64



config X86_REQUIRED_FEATURE_XMM2

	def_bool y

	depends on X86_64



config X86_REQUIRED_FEATURE_LM

	def_bool y

	depends on X86_64



config X86_DISABLED_FEATURE_UMIP

	def_bool y

	depends on !X86_UMIP



config X86_DISABLED_FEATURE_VME

	def_bool y

	depends on X86_64



config X86_DISABLED_FEATURE_K6_MTRR

	def_bool y

	depends on X86_64



config X86_DISABLED_FEATURE_CYRIX_ARR

	def_bool y

	depends on X86_64



config X86_DISABLED_FEATURE_CENTAUR_MCR

	def_bool y

	depends on X86_64



config X86_DISABLED_FEATURE_PCID

	def_bool y

	depends on !X86_64



config X86_DISABLED_FEATURE_PKU

	def_bool y

	depends on !X86_INTEL_MEMORY_PROTECTION_KEYS



config X86_DISABLED_FEATURE_OSPKE

	def_bool y

	depends on !X86_INTEL_MEMORY_PROTECTION_KEYS



config X86_DISABLED_FEATURE_LA57

	def_bool y

	depends on !X86_5LEVEL



config X86_DISABLED_FEATURE_PTI

	def_bool y

	depends on !MITIGATION_PAGE_TABLE_ISOLATION



config X86_DISABLED_FEATURE_RETPOLINE

	def_bool y

	depends on !MITIGATION_RETPOLINE



config X86_DISABLED_FEATURE_RETPOLINE_LFENCE

	def_bool y

	depends on !MITIGATION_RETPOLINE



config X86_DISABLED_FEATURE_RETHUNK

	def_bool y

	depends on !MITIGATION_RETHUNK



config X86_DISABLED_FEATURE_UNRET

	def_bool y

	depends on !MITIGATION_UNRET_ENTRY



config X86_DISABLED_FEATURE_CALL_DEPTH

	def_bool y

	depends on !MITIGATION_CALL_DEPTH_TRACKING



config X86_DISABLED_FEATURE_LAM

	def_bool y

	depends on !ADDRESS_MASKING



config X86_DISABLED_FEATURE_ENQCMD

	def_bool y

	depends on !INTEL_IOMMU_SVM



config X86_DISABLED_FEATURE_SGX

	def_bool y

	depends on !X86_SGX



config X86_DISABLED_FEATURE_XENPV

	def_bool y

	depends on !XEN_PV



config X86_DISABLED_FEATURE_TDX_GUEST

	def_bool y

	depends on !INTEL_TDX_GUEST



config X86_DISABLED_FEATURE_USER_SHSTK

	def_bool y

	depends on !X86_USER_SHADOW_STACK



config X86_DISABLED_FEATURE_IBT

	def_bool y

	depends on !X86_KERNEL_IBT



config X86_DISABLED_FEATURE_FRED

	def_bool y

	depends on !X86_FRED



config X86_DISABLED_FEATURE_SEV_SNP

	def_bool y

	depends on !KVM_AMD_SEV



config X86_DISABLED_FEATURE_INVLPGB

	def_bool y

	depends on !BROADCAST_TLB_FLUSH