From: Paolo Bonzini <pbonzini@redhat.com>
To: Jim Mattson <jmattson@google.com>, "Li,Rongqing" <lirongqing@baidu.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
kvm list <kvm@vger.kernel.org>,
the arch/x86 maintainers <x86@kernel.org>,
"H . Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@alien8.de>,
Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Joerg Roedel <joro@8bytes.org>,
Wanpeng Li <wanpengli@tencent.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>
Subject: Re: [PATCH] [RFC] kvm: x86: emulate APERF/MPERF registers
Date: Mon, 27 Apr 2020 21:10:26 +0200 [thread overview]
Message-ID: <f3c2cc31-6388-f7b5-48fd-fb19d059eea3@redhat.com> (raw)
In-Reply-To: <CALMp9eQrGuqzy_ZRu+qU3A7PRkoi8JHWFRpm---cMhp9+J4j8A@mail.gmail.com>
On 27/04/20 19:30, Jim Mattson wrote:
>>>> I would like to see performance data before enabling this
>>>> unconditionally.
>>> I wouldn't want this to be enabled unconditionally anyway,
>>> because you need to take into account live migration to and from
>>> processors that do not have APERF/MPERF support.
>>>
>>> Paolo
>> I will add a kvm parameter to consider whether enable MPERF/APERF
>> emulations, and make default value to false
>
> Wouldn't it be better to add a per-VM capability to enable this
> feature?
Yes, you it would be better to use KVM_ENABLE_CAP indeed.
Paolo
next prev parent reply other threads:[~2020-04-27 19:10 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-24 5:08 [PATCH] [RFC] kvm: x86: emulate APERF/MPERF registers Li RongQing
2020-04-24 10:01 ` Peter Zijlstra
2020-04-24 14:46 ` Sean Christopherson
2020-04-24 16:25 ` Jim Mattson
2020-04-24 16:30 ` Paolo Bonzini
2020-04-26 3:24 ` 答复: " Li,Rongqing
2020-04-27 17:30 ` Jim Mattson
2020-04-27 19:10 ` Paolo Bonzini [this message]
2020-04-26 3:22 ` 答复: " Li,Rongqing
2020-04-26 8:30 ` Li,Rongqing
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