Re: [RFC PATCH 05/56] x86/bugs: Reset spectre_v2 mitigations

Borislav Petkov
2025-11-03T20:28:35Z

On Mon, Nov 03, 2025 at 08:10:39PM +0000, Kaplan, David wrote:
> Do you really want it all in one big function? Or just to relocate all the
> *_reset_mitigation() functions to a single place so they can all go under
> one ifdef?
>
> I can do it in one big function, but it'd probably look something like:
>
> /* Reset spectre_v1 */
> setup_clear_cpu_cap(X86_FEATURE_FENCE_SWAPGS_USER);
> setup_clear_cpu_cap(X86_FEATURE_FENCE_SWAPGS_KERNEL);
> spectre_v1_mitigation = SPECTRE_V1_MITIGATION_AUTO;
> /* Reset mds */
> setup_clear_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF);
> static_branch_disable(&cpu_buf_idle_clear);
> mds_mitigation = IS_ENABLED(CONFIG_MITIGATION_MDS) ?
> MDS_MITIGATION_AUTO : MDS_MITIGATION_OFF;
> /* Reset spectre_v2 */
> Etc.

Yap, that's what I thought too.

Since there's no point to have separate functions, the comment separation is
perfectly sufficient, I'd say.

Thx.

--
Regards/Gruss,
Boris.