Re: [PATCH] x86: Clear LAM and FRED feature bits

[Maciej Wieczor-Retman]

On 2025-07-22 at 07:11:47 -0700, Dave Hansen wrote:
>On 7/22/25 02:08, Xin Li wrote:
>>> +    /*
>>> +     * If a feature is disabled during compile time clear its feature
>>> +     * bit to prevent it from showing up in the x86_capability bitmask.
>>> +     */
>>> +    if (!cpu_feature_enabled(X86_FEATURE_LAM))
>>> +        setup_clear_cpu_cap(X86_FEATURE_LAM);
>>> +
>>> +    if (!cpu_feature_enabled(X86_FEATURE_FRED))
>>> +        setup_clear_cpu_cap(X86_FEATURE_FRED);
>>> +
>> 
>> The following code will work as a generic fix:
>> 
>>     c->x86_capability[i] &= ~DISABLED_MASK(i);
>> 
>> And DISABLED_MASK(x) needs to be defined like DISABLED_MASK_BIT_SET(x).
>
>Maciej, I would much rather have a generic fix than force everyone to
>remember to open-code this for every new feature that gets disabled.

I'll apply Xin's suggestions, test and resend.

-- 
Kind regards
Maciej Wieczór-Retman