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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Peter Hilber <peter.hilber@opensynergy.com>,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        kvmarm@lists.linux.dev
Cc:     Peter Hilber <peter.hilber@opensynergy.com>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>,
        Richard Cochran <richardcochran@gmail.com>,
        John Stultz <jstultz@google.com>,
        Stephen Boyd <sboyd@kernel.org>, netdev@vger.kernel.org,
        Marc Zyngier <maz@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Zenghui Yu <yuzenghui@huawei.com>,
        Sean Christopherson <seanjc@google.com>
Subject: Re: [RFC PATCH 4/4] treewide: Use clocksource id for struct
 system_counterval_t
In-Reply-To: <20230818011256.211078-5-peter.hilber@opensynergy.com>
References: <20230818011256.211078-1-peter.hilber@opensynergy.com>
 <20230818011256.211078-5-peter.hilber@opensynergy.com>
Date:   Fri, 15 Sep 2023 15:30:23 +0200
Message-ID: <87cyyj1s40.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Peter!

On Fri, Aug 18 2023 at 03:12, Peter Hilber wrote:
> --- a/arch/x86/kernel/tsc.c
> +++ b/arch/x86/kernel/tsc.c
> @@ -1313,7 +1313,7 @@ struct system_counterval_t convert_art_to_tsc(u64 art)
>  	res += tmp + art_to_tsc_offset;
>  
>  	return (struct system_counterval_t) {
> -		.cs = have_art ? &clocksource_tsc : NULL,
> +		.cs_id = have_art ? CSID_TSC : CSID_GENERIC,
>  		.cycles = res

Can you please change all of this so that:

    patch 1:   Adds cs_id to struct system_counterval_t
    patch 2-4: Add the clocksource ID and set the cs_id field
    patch 5:   Switches the core to evaluate cs_id
    patch 6:   Remove the cs field from system_counterval_t


> --- a/include/linux/timekeeping.h
> +++ b/include/linux/timekeeping.h
> @@ -270,12 +270,12 @@ struct system_device_crosststamp {
>   * struct system_counterval_t - system counter value with the pointer to the
>   *				corresponding clocksource
>   * @cycles:	System counter value
> - * @cs:		Clocksource corresponding to system counter value. Used by
> + * @cs_id:	Clocksource corresponding to system counter value. Used by
>   *		timekeeping code to verify comparibility of two cycle values

That comment is inaccurate. It's not longer the clocksource itself. It's
the ID which is used for validation.

Thanks,

        tglx