linux-kernel - Re: [PATCH v4 02/34] ASoC: Intel: avs: Include CPUID header at file scope

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Message-ID: <aKNDZ3mWYUABwOzJ@lx-t490>
Date: Mon, 18 Aug 2025 17:14:47 +0200
From: "Ahmed S. Darwish" <darwi@...utronix.de>
To: Borislav Petkov <bp@...en8.de>
Cc: Ingo Molnar <mingo@...hat.com>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Andrew Cooper <andrew.cooper3@...rix.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	David Woodhouse <dwmw2@...radead.org>,
	Sean Christopherson <seanjc@...gle.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Sohil Mehta <sohil.mehta@...el.com>,
	John Ogness <john.ogness@...utronix.de>, x86@...nel.org,
	x86-cpuid@...ts.linux.dev, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4 02/34] ASoC: Intel: avs: Include CPUID header at file
 scope

Hi Boris,

On Mon, 18 Aug 2025, Borislav Petkov wrote:
>
> I'm guessing that:
>
> https://lore.kernel.org/r/aGv8AWwHbi5seDxi@lx-t490
>
> still needs to happen yet?
>
> Because I don't see it in this set...
>

Yeah, I discovered that I need to do the X86_FEATURE integration within
the CPUID model before touching the CPUID(0x15) call sites.

Quoting the cover:

  State of Affairs: By now, all CPUID leaves which do not interact with
  the X86_FEATURE mechanism(s) has been transformed to the CPUID model.
  Remaining leaves have dependencies on X86_FEATURE.

  For example, some callsites _directly_ enumerate CPUID(0x15)
  [ART_CPUID_LEAF / CPUID_LEAF_TSC] even though that leaf has important
  dependencies on X86_FEATURE_ART and its tsc_async_resets flag.

  The CPUID parser work will not propagate such call sites brokedness and
  will integrate the X86_FEATURE infrastructure within it first.

As I mentioned in the Bhyve thread, this shall also include a directed
acyclic graph of dependencies for the X86_FEATURE flags themselves:

  https://lore.kernel.org/lkml/aKL0WlA4wIU8l9RT@lx-t490

v5 should cover this.

Thanks!

--
Ahmed S. Darwish
Linutronix GmbH