No, you don't ignore the CPUID feature bit. You use the CPUID to enable the feature by default, but override that default by blacklisting specific models that y

No, you don't ignore the CPUID feature bit. You use the CPUID to enable the feature by default, but override that default by blacklisting specific models that you know would have undesirable implementations. So what you would do for PDEP/PEXT would be use_pdep = cpuid.supports_bmi2() && !cpuid.is_amd_before_zen3() and not use_pdep = cpuid.is_intel_haswell_or_later()