linux-kernel - Re: [PATCH] x86/cpuinfo: Clear X86_FEATURE

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Message-ID: <CAKgze5b6hvxRm0Yrj19yyBwAns-CdDs7furJuevu3-3Wsf99MA@mail.gmail.com>
Date:   Mon, 4 Jul 2022 11:22:39 -0300
From:   Martin Fernandez <martin.fernandez@...ypsium.com>
To:     linux-kernel@...r.kernel.org
Cc:     bp@...en8.de, dave.hansen@...ux.intel.com, x86@...nel.org,
        mingo@...hat.com, tglx@...utronix.de,
        kirill.shutemov@...ux.intel.com, daniel.gutson@...ypsium.com,
        hughsient@...il.com, alex.bazhaniuk@...ypsium.com,
        Martin Fernandez <martin.fernandez@...ypsium.com>
Subject: Re: [PATCH] x86/cpuinfo: Clear X86_FEATURE_TME if TME/MKTME is
 disabled by BIOS

On 7/4/22, Martin Fernandez <martin.fernandez@...ypsium.com> wrote:
> Right now the only way to check this is by greping the kernel logs,
> which is inconvinient. This is currently checked for fwupd for
> example.
>
> I understand that cpuinfo is supposed to report every feature in the
> cpu but since AMD is doing the same for sme/sev I think is good to
> have this for Intel too.
>
> Signed-off-by: Martin Fernandez <martin.fernandez@...ypsium.com>
> ---
>  arch/x86/kernel/cpu/intel.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
> index fd5dead8371c..7311172aceaf 100644
> --- a/arch/x86/kernel/cpu/intel.c
> +++ b/arch/x86/kernel/cpu/intel.c
> @@ -570,6 +570,8 @@ static void detect_tme(struct cpuinfo_x86 *c)
>
>  	if (!TME_ACTIVATE_LOCKED(tme_activate) ||
> !TME_ACTIVATE_ENABLED(tme_activate)) {
>  		pr_info_once("x86/tme: not enabled by BIOS\n");
> +		if (mktme_status == MKTME_UNINITIALIZED)
> +			clear_cpu_cap(c, X86_FEATURE_TME);
>  		mktme_status = MKTME_DISABLED;
>  		return;
>  	}
> --
> 2.30.2
>
>

I'm sorry, disregard this patch. I wrongly sent an old one. My apologies.