Re: [PATCH 3/6] x86/match-cpu: Introduce X86_MATCH_VFM() and convert intel_idle_ids[]

[Jan Beulich <jbeulich@suse.com>]

On 16.07.2025 19:31, Andrew Cooper wrote:
> mwait-idle's ICPU() is the most convenient place to get started.  Introduce
> X86_MATCH_CPU() and X86_MATCH_VFM() following their Linux counterparts.
> 
> This involves match-cpu.h including more headers, which in turn allows us to
> drop a few.

intel-cpu.h doesn't really need to move, does it? Conceivably there can be users
of match-cpu.h which don't need the Intel constants. Hence no point in forcing
them to see those.

> No functional change.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> ---
> CC: Jan Beulich <JBeulich@suse.com>
> CC: Roger Pau Monné <roger.pau@citrix.com>
> 
> We now have X86_FEATURE_ANY and X86_FEATURE_ALWAYS as aliases of LM.  Given
> the contexts they're used in, I've left the naming as-is.

What's wrong with sticking to ALWAYS, which we already have?

> It's a bit nasty (preprocessing wise) triple-expanding VFM in X86_MATCH_VFM(),
> but we need an Integer Constant Expression.

Not sure what alternative you're alluding to, or in fact what nastiness you're
seeing. But maybe I'm getting "triple-expanding" wrong: To me that means going
through three layers of expansion, when you may mean the fact that
X86_MATCH_VFM() evaluates its parameter three times. If so - yes, but as you
say: What do you do (in this case).

Jan