linux-kernel - Re: [PATCH v2 06/35] x86/bugs: Restructure mmio mitigation

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Message-ID: <20241114050142.s6gjtna2dnsevnfp@desk>
Date: Wed, 13 Nov 2024 21:03:58 -0800
From: Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>
To: David Kaplan <david.kaplan@....com>
Cc: Thomas Gleixner <tglx@...utronix.de>, Borislav Petkov <bp@...en8.de>,
	Peter Zijlstra <peterz@...radead.org>,
	Josh Poimboeuf <jpoimboe@...nel.org>,
	Ingo Molnar <mingo@...hat.com>,
	Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
	"H . Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 06/35] x86/bugs: Restructure mmio mitigation

On Tue, Nov 05, 2024 at 03:54:26PM -0600, David Kaplan wrote:
> +static void __init mmio_update_mitigation(void)
> +{
> +	if (!boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA))
> +		return;
> +
> +	if (mitigate_any_verw())
> +		mmio_mitigation = MMIO_MITIGATION_VERW;

Same as TAA, UCODE_NEEDED can't be set irrespective of microcode.

> +
> +	pr_info("%s\n", mmio_strings[mmio_mitigation]);

This should be in the 'else' part of below condition, otherwise they can
print conflicting mitigation status.

> +	if (boot_cpu_has_bug(X86_BUG_MMIO_UNKNOWN))
> +		pr_info("Unknown: No mitigations\n");
> +}