Re: [PATCH v3 10/20] i386/cpu: Add missing migratable xsave features

[Zhao Liu <zhao1.liu@intel.com>]

On Mon, Oct 27, 2025 at 06:19:40PM +0800, Zhao Liu wrote:
> Date: Mon, 27 Oct 2025 18:19:40 +0800
> From: Zhao Liu <zhao1.liu@intel.com>
> Subject: Re: [PATCH v3 10/20] i386/cpu: Add missing migratable xsave
>  features
> 
> > Though the feature expansion in x86_cpu_expand_features() under
> > 
> > 	if (xcc->max_features) {
> > 		...
> > 	}
> > 
> > only enables migratable features when cpu->migratable is true,
> > x86_cpu_enable_xsave_components() overwrite the value later.
> 
> I have not changed the related logic, and this was intentional...too,
> which is planed to be cleaned up after CET.

There's only 1 use case of migratable_flags, so I would try to drop
it directly.

The xsave-managed/enabled feature is not suitable as the configurable
feature. Therefore, it is best to keep it non-configurable as it is
currently.

At least with this fix, the support for the new xsave feature —
including APX next — will not be broken, and the migratable flag
refactoring will become a separate RFC.

Regards,
Zhao