On June 20, 2025 4:46:21 PM PDT, Xin Li <xin@xxxxxxxxx> wrote: >On 6/20/2025 10:31 AM, Kirill A. Shutemov wrote: >> On Fri, Jun 20, 2025 at 08:36:30AM -0700, Xin Li wrote: >>> On 6/20/2025 6:53 AM, Kirill A. Shutemov wrote: >>>> diff --git a/arch/x86/Kconfig.cpufeatures b/arch/x86/Kconfig.cpufeatures >>>> index 250c10627ab3..9574c198fc08 100644 >>>> --- a/arch/x86/Kconfig.cpufeatures >>>> +++ b/arch/x86/Kconfig.cpufeatures >>>> @@ -124,6 +124,10 @@ config X86_DISABLED_FEATURE_PCID >>>> def_bool y >>>> depends on !X86_64 >>>> +config X86_DISABLED_FEATURE_LASS >>>> + def_bool y >>>> + depends on !X86_64 >>>> + >>>> config X86_DISABLED_FEATURE_PKU >>>> def_bool y >>>> depends on !X86_INTEL_MEMORY_PROTECTION_KEYS >>> >>> You don't need to add X86_DISABLED_FEATURE_LASS, because the LASS code >>> is NOT optional at build time, i.e., you now don't have CONFIG_X86_LASS. >> >> Hmm. But it is optional. It depends on CONFIG_X86_64. I don't think we >> want it to be advertised on 32-bit kernels. >> > >I kind of ignore 32-bit... > >But I simply hate adding a disabled feature that depends on !X86_64; >x86_64 has a broad scope, and new CPU features are often intentionally >not enabled for 32-bit. > >(X86_DISABLED_FEATURE_PCID is the only one before LASS) > > More importantly, it is wrong. The 32-bit build can depend on this feature not existing, therefore it SHOULD be listed as a disabled feature.
