Re: [PATCHv3 09/17] x86/mm: Implement page_keyid() using page_ext

[Kirill A. Shutemov]

On Wed, Jun 13, 2018 at 06:20:10PM +0000, Dave Hansen wrote:
> > +int page_keyid(const struct page *page)
> > +{
> > +	if (mktme_status != MKTME_ENABLED)
> > +		return 0;
> > +
> > +	return lookup_page_ext(page)->keyid;
> > +}
> > +EXPORT_SYMBOL(page_keyid);
> 
> Please start using a proper X86_FEATURE_* flag for this.  It will give
> you all the fancy static patching that you are missing by doing it this way.

There's no MKTME CPU feature.

Well, I guess we can invent syntactic one or just use static key directly.

Let's see how it behaves performance-wise before optimizing this.

-- 
 Kirill A. Shutemov