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Date:   Wed, 15 Nov 2023 08:49:36 +0000
Message-ID: <865y231jvj.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     David Dai <davidai@google.com>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Saravana Kannan <saravanak@google.com>,
        Quentin Perret <qperret@google.com>,
        Masami Hiramatsu <mhiramat@google.com>,
        Will Deacon <will@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Oliver Upton <oliver.upton@linux.dev>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Pavan Kondeti <quic_pkondeti@quicinc.com>,
        Gupta Pankaj <pankaj.gupta@amd.com>,
        Mel Gorman <mgorman@suse.de>, kernel-team@android.com,
        linux-pm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 1/2] dt-bindings: cpufreq: add virtual cpufreq device
In-Reply-To: <20231111014933.1934562-2-davidai@google.com>
References: <20231111014933.1934562-1-davidai@google.com>
        <20231111014933.1934562-2-davidai@google.com>
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On Sat, 11 Nov 2023 01:49:29 +0000,
David Dai <davidai@google.com> wrote:
> 
> Adding bindings to represent a virtual cpufreq device.
> 
> Virtual machines may expose MMIO regions for a virtual cpufreq device
> for guests to read frequency information or to request frequency
> selection. The virtual cpufreq device has an individual controller for
> each frequency domain.

I would really refrain form having absolute frequencies here. A
virtual machine can be migrated, and there are *zero* guarantees that
the target system has the same clock range as the source.

This really should be a relative number, much like the capacity. That,
at least, can be migrated across systems.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.