linux-kernel - Re: [PATCH v11 04/13] x86/cpufeatures: Add Bandwidth Monitoring Event Configuration feature flag

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Date:   Mon, 9 Jan 2023 19:58:13 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Babu Moger <babu.moger@....com>
Cc:     corbet@....net, reinette.chatre@...el.com, tglx@...utronix.de,
        mingo@...hat.com, fenghua.yu@...el.com,
        dave.hansen@...ux.intel.com, x86@...nel.org, hpa@...or.com,
        paulmck@...nel.org, akpm@...ux-foundation.org,
        quic_neeraju@...cinc.com, rdunlap@...radead.org,
        damien.lemoal@...nsource.wdc.com, songmuchun@...edance.com,
        peterz@...radead.org, jpoimboe@...nel.org, pbonzini@...hat.com,
        chang.seok.bae@...el.com, pawan.kumar.gupta@...ux.intel.com,
        jmattson@...gle.com, daniel.sneddon@...ux.intel.com,
        sandipan.das@....com, tony.luck@...el.com, james.morse@....com,
        linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
        bagasdotme@...il.com, eranian@...gle.com,
        christophe.leroy@...roup.eu, jarkko@...nel.org,
        adrian.hunter@...el.com, quic_jiles@...cinc.com,
        peternewman@...gle.com
Subject: Re: [PATCH v11 04/13] x86/cpufeatures: Add Bandwidth Monitoring
 Event Configuration feature flag

On Mon, Jan 09, 2023 at 10:43:56AM -0600, Babu Moger wrote:
> diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
> index 00045123f418..db5287c06b65 100644
> --- a/arch/x86/include/asm/cpufeatures.h
> +++ b/arch/x86/include/asm/cpufeatures.h
> @@ -308,6 +308,7 @@
>  #define X86_FEATURE_CALL_DEPTH		(11*32+19) /* "" Call depth tracking for RSB stuffing */
>  #define X86_FEATURE_MSR_TSX_CTRL	(11*32+20) /* "" MSR IA32_TSX_CTRL (Intel) implemented */
>  #define X86_FEATURE_SMBA		(11*32+21) /* Slow Memory Bandwidth Allocation */
> +#define X86_FEATURE_BMEC		(11*32+22) /* Bandwidth Monitoring Event Configuration */

If those flags are meant only for internal kernel code use - it looks like it -
and userspace doesn't care, pls put "" in front of both in the comment like the
others above them do.

This way they won't be visible in /proc/cpuinfo.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette