From: Peter Zijlstra <peterz@infradead.org>
To: Li RongQing <lirongqing@baidu.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
x86@kernel.org, hpa@zytor.com, bp@alien8.de, mingo@redhat.com,
tglx@linutronix.de, joro@8bytes.org, jmattson@google.com,
wanpengli@tencent.com, vkuznets@redhat.com,
sean.j.christopherson@intel.com, pbonzini@redhat.com
Subject: Re: [PATCH][v2] kvm: x86: emulate APERF/MPERF registers
Date: Wed, 29 Apr 2020 10:54:40 +0200 [thread overview]
Message-ID: <20200429085440.GG13592@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <1588139196-23802-1-git-send-email-lirongqing@baidu.com>
On Wed, Apr 29, 2020 at 01:46:36PM +0800, Li RongQing wrote:
> Guest kernel reports a fixed cpu frequency in /proc/cpuinfo,
> this is confused to user when turbo is enable, and aperf/mperf
> can be used to show current cpu frequency after 7d5905dc14a
> "(x86 / CPU: Always show current CPU frequency in /proc/cpuinfo)"
> so we should emulate aperf mperf to achieve it
>
> the period of aperf/mperf in guest mode are accumulated as
> emulated value, and add per-VM knod to enable emulate mperfaperf
>
> diff v1:
> 1. support AMD
> 2. support per-vm capability to enable
Would it make sense to provide a pass-through APERF/MPERF for
KVM_HINTS_REALTIME ? Because that hint guarantees we have a 1:1 vCPU:CPU
binding and guaranteed no over-commit.
next prev parent reply other threads:[~2020-04-29 8:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-29 5:46 [PATCH][v2] kvm: x86: emulate APERF/MPERF registers Li RongQing
2020-04-29 8:54 ` Peter Zijlstra [this message]
2020-04-29 9:43 ` 答复: " Li,Rongqing
2020-04-29 10:21 ` Paolo Bonzini
2020-04-30 1:45 ` 答复: " Li,Rongqing
2020-04-30 6:49 ` Xiaoyao Li
2020-04-30 9:50 ` 答复: " Li,Rongqing
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