Re: [PATCH v10 2/6] x86/sev: Initialize RMPOPT configuration MSRs

[Borislav Petkov]

On Tue, Jul 21, 2026 at 09:26:48AM -0500, Kalra, Ashish wrote:
> That's why v7 moved to a runtime check. In v11 (as i mentioned) this will be a small local helper,  it will also handles two things
> the cap-clear can't:
>   - a contiguous (non-segmented) RMP, where RMPOPT isn't usable even with X86_FEATURE_RMPOPT set.

That's the point of clearing the flag - to mark it non-usable.

>   - SNP being disabled at runtime (CC_ATTR_HOST_SEV_SNP).

Same as RMPOPT being not usable follows from disabled SNP.

>   static bool rmpopt_capable(void)
>   {
>         return cpu_feature_enabled(X86_FEATURE_RMPOPT) &&
>                cc_platform_has(CC_ATTR_HOST_SEV_SNP) &&
>                (rmp_cfg & MSR_AMD64_SEG_RMP_ENABLED) &&
>                rmp_segment_table;
>   }

But yes, this is a local helper so that's good enough.

We can always change it later if needed.

Thx.

-- 
Regards/Gruss,
    Boris.

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