Re: [PATCH v8 02/10] x86/bhi: Make clear_bhb_loop() effective on newer CPUs

Borislav Petkov
2026-03-26T10:02:13Z

On Thu, Mar 26, 2026 at 01:39:34AM -0700, Pawan Gupta wrote:
> I believe the equivalent for cpu_feature_enabled() in asm is the
> ALTERNATIVE. Please let me know if I am missing something.

Yes, you are.

The point is that you don't want to stick those alternative calls inside some
magic bhb_loop function but hand them in from the outside, as function
arguments.

Basically what I did.

Then you were worried about this being C code and it had to be noinstr... So
that outer function can be rewritten in asm, I think, and still keep it well
separate.

I'll try to rewrite it once I get a free minute, and see how it looks.

--
Regards/Gruss,
Boris.