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From:   Paolo Bonzini <pbonzini@redhat.com>
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Date:   Fri, 5 Jun 2020 13:15:51 +0200
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On 05/06/20 11:41, Li,Rongqing wrote:
>>
>> As you said, "Pass-though: it is only suitable for KVM_HINTS_REALTIME", which
>> means, KVM needs to make sure the kvm->arch.aperfmperf_mode value could
>> "only" be set to KVM_APERFMPERF_PT when the check
>> kvm_para_has_hint(KVM_HINTS_REALTIME) is passed.
>>
> pining vcpu can ensure that guest get correct mperf/aperf, but a user
> has the choice to not pin, at that condition, do not think it is bug, this wants to say

Also, userspace can also pin without exposing KVM_HINTS_REALTIME.  So
it's better not to check.

Paolo