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Subject: Re: [PATCH v3] LoongArch: KVM: Add PMU support
To: Markus Elfring <Markus.Elfring@web.de>, loongarch@lists.linux.dev,
 kernel-janitors@vger.kernel.org, maobibo@loongson.cn
Cc: LKML <linux-kernel@vger.kernel.org>, Huacai Chen <chenhuacai@kernel.org>,
 Paolo Bonzini <pbonzini@redhat.com>, Tianrui Zhao <zhaotianrui@loongson.cn>,
 Wang Xuerui <kernel@xen0n.name>
References: <20240424091813.1471440-1-gaosong@loongson.cn>
 <e68e09e0-75f3-43b8-b947-22cc0d1a0dae@web.de>
From: gaosong <gaosong@loongson.cn>
Message-ID: <b8818597-2770-f2a3-03bd-1653cd26fc78@loongson.cn>
Date: Mon, 29 Apr 2024 15:32:09 +0800
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在 2024/4/25 下午3:18, Markus Elfring 写道:
> …
>> On KVM side. we save the host PMU CSRs into structure kvm_context.
>> If the host supports the PMU feature. When entering guest mode.
>> we save the host PMU CSRs and restore the guest PMU CSRs.
> …
>
> I suggest to reconsider the usage of a few dots in such a wording approach.
>
>
> …
> Signed-off-by: Song Gao <gaosong@loongson.cn>
>
> v2->V3:
> …
>
> * Please put your version descriptions behind a marker line.
>    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9-rc5#n713
Got  it,  thank for you suggestion.
> * How do you think about to avoid the repetition of version identifiers here?
I'm new to this, is the following example correct?

[...]

Signed-off-by: Song Gao <gaosong@loongson.cn>
---

v4:
   - Use the macro kvm_read_clear_hw_gcsr to optimize the code
     and remove redundant code.

V3:
   - When saving the PMU context, clear the CTRL register
      before reading the CNTR register.
   - Put kvm_lose_pmu() in kvm_handler_exit().

v2:
   - Add new vcpu->request flag KVM_REQ_PMU. If we use PMU,
     We need to set this flag;
   - Add kvm_check_pmu() to kvm_pre_enter_guest();
   - On _kvm_setcsr(), after modifying the PMU CSR register value,
      if we use PMU, we need to set KVM_REQ_PMU.

Patch v3: 
https://lore.kernel.org/all/20240424091813.1471440-1-gaosong@loongson.cn/
Patch v2: 
https://lore.kernel.org/all/20240417065236.500011-1-gaosong@loongson.cn/
Patch v1: 
https://lore.kernel.org/all/20240410095812.2943706-1-gaosong@loongson.cn/

---

[...]

Regards.
Song Gao
>
> Regards,
> Markus