Re: [PATCH v12 4/4] x86/cpu: Clear feature bits whose dependencies were cleared

[Maciej Wieczor-Retman]

On 2026-03-30 at 23:41:57 +0200, Ahmed S. Darwish wrote:
>On Fri, 27 Mar 2026, H. Peter Anvin wrote:
>>
>> Thinking about it, if this is discovered at runtime, it is really too late,
>> because in a sense we have miscompiled the kernel with unwanted code (as we
>> should have compiled out these features just as with other DISABLED features.)
>>
>> This ultimately reflects a failed dependency in Kconfig.cpufeatures, which may
>> have caused kconfig to do the Wrong Thing[TM]. So at the very least it might
>> be a good thing to print a message here saying Kconfig.cpufeatures should be
>> fixed.
>>
>> The better option, which I don't know how difficult it would be, would be to
>> make the dependencies available to Kconfig. This sounds like something that
>> would fall in the scope of Ahmed's rework rather than this patchset, though
>> (Ahmed, would you agree?)
>>
>
>Definitely!
>
>If the CPUID model sent some days ago is to be merged, (*) then all these
>dependencies should be encoded within x86-cpuid-db, especially that it now
>covers all the synthetic X86_FEATURE flags as well.

Hi! I'm still testing/browsing through the cpuid patchset. But I was wondering
what did you mean about encoding these dependencies? That they are encoded in
your patchset or that they should be?

-- 
Kind regards
Maciej Wieczór-Retman