Re: [RFC PATCH v2 2/6] kvm: arm64: Add support for get_cur_cpufreq service

From: Bagas Sanjaya <bagasdotme@gmail.com>
To: David Dai <davidai@google.com>,
	"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>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Jonathan Corbet <corbet@lwn.net>, Marc Zyngier <maz@kernel.org>,
	Oliver Upton <oliver.upton@linux.dev>,
	James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Zenghui Yu <yuzenghui@huawei.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Lorenzo Pieralisi <lpieralisi@kernel.org>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
	Daniel Bristot de Oliveira <bristot@redhat.com>,
	Valentin Schneider <vschneid@redhat.com>
Cc: Saravana Kannan <saravanak@google.com>,
	kernel-team@android.com, linux-pm@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev
Subject: Re: [RFC PATCH v2 2/6] kvm: arm64: Add support for get_cur_cpufreq service
Date: Sat, 1 Apr 2023 10:12:15 +0700	[thread overview]
Message-ID: <ZCehD15QJyDapG3u@debian.me> (raw)
In-Reply-To: <20230331014356.1033759-3-davidai@google.com>

On Thu, Mar 30, 2023 at 06:43:46PM -0700, David Dai wrote:
> diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
> index 62de0768d6aa..b0ff0ad700bf 100644
> --- a/Documentation/virt/kvm/api.rst
> +++ b/Documentation/virt/kvm/api.rst
> @@ -8380,6 +8380,14 @@ structure.
>  When getting the Modified Change Topology Report value, the attr->addr
>  must point to a byte where the value will be stored or retrieved from.
>  
> +8.40 KVM_CAP_GET_CUR_CPUFREQ
> +------------------------
> +
> +:Architectures: arm64
> +
> +This capability indicates that KVM supports getting the
> +frequency of the current CPU that the vCPU thread is running on.
> +
>  9. Known KVM API problems
>  =========================
>  
> diff --git a/Documentation/virt/kvm/arm/get_cur_cpufreq.rst b/Documentation/virt/kvm/arm/get_cur_cpufreq.rst
> new file mode 100644
> index 000000000000..06e0ed5b3868
> --- /dev/null
> +++ b/Documentation/virt/kvm/arm/get_cur_cpufreq.rst
> @@ -0,0 +1,21 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +get_cur_cpufreq support for arm/arm64
> +=============================
> +
> +Get_cur_cpufreq support is used to get current frequency(in KHz) of the
> +current CPU that the vCPU thread is running on.
> +
> +* ARM_SMCCC_VENDOR_HYP_KVM_GET_CUR_CPUFREQ_FUNC_ID: 0x86000040
> +
> +This hypercall uses the SMC32/HVC32 calling convention:
> +
> +ARM_SMCCC_VENDOR_HYP_KVM_GET_CUR_CPUFREQ_FUNC_ID
> +    ==============    ========    =====================================
> +    Function ID:      (uint32)    0x86000040
> +    Return Values:    (int32)     NOT_SUPPORTED(-1) on error, or
> +                      (uint32)    Frequency in KHz of current CPU that the
> +                                  vCPU thread is running on.
> +    Endianness:                   Must be the same endianness
> +                                  as the host.
> +    ==============    ========    =====================================

Sphinx reports htmldocs warnings:
/home/bagas/repo/linux-kernel/Documentation/virt/kvm/api.rst:8384: WARNING: Title underline too short.

8.40 KVM_CAP_GET_CUR_CPUFREQ
------------------------
/home/bagas/repo/linux-kernel/Documentation/virt/kvm/api.rst:8384: WARNING: Title underline too short.

8.40 KVM_CAP_GET_CUR_CPUFREQ
------------------------
/home/bagas/repo/linux-kernel/Documentation/virt/kvm/api.rst:8404: WARNING: Title underline too short.

I have applied the fixup:

---- >8 ----

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 8f905456e2b4a1..baf8a4c43b5839 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -8381,7 +8381,7 @@ When getting the Modified Change Topology Report value, the attr->addr
 must point to a byte where the value will be stored or retrieved from.
 
 8.40 KVM_CAP_GET_CUR_CPUFREQ
-------------------------
+----------------------------
 
 :Architectures: arm64
 
diff --git a/Documentation/virt/kvm/arm/get_cur_cpufreq.rst b/Documentation/virt/kvm/arm/get_cur_cpufreq.rst
index 06e0ed5b3868d7..76f112efb99f92 100644
--- a/Documentation/virt/kvm/arm/get_cur_cpufreq.rst
+++ b/Documentation/virt/kvm/arm/get_cur_cpufreq.rst
@@ -11,11 +11,12 @@ current CPU that the vCPU thread is running on.
 This hypercall uses the SMC32/HVC32 calling convention:
 
 ARM_SMCCC_VENDOR_HYP_KVM_GET_CUR_CPUFREQ_FUNC_ID
-    ==============    ========    =====================================
+
+    ==============    ========    ========================================
     Function ID:      (uint32)    0x86000040
     Return Values:    (int32)     NOT_SUPPORTED(-1) on error, or
                       (uint32)    Frequency in KHz of current CPU that the
                                   vCPU thread is running on.
     Endianness:                   Must be the same endianness
                                   as the host.
-    ==============    ========    =====================================
+    ==============    ========    ========================================

Thanks.

-- 
An old man doll... just what I always wanted! - Clara
