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Message-ID: <341cffc3-d0b9-2ef7-3c6e-c48ea179699b@gmail.com>
Date:   Fri, 14 Oct 2022 16:08:20 +0800
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Subject: Re: [PATCH v3 5/7] KVM: x86/pmu: Defer counter emulated overflow via
 pmc->prev_counter
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To:     Sean Christopherson <seanjc@google.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
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 <20220831085328.45489-6-likexu@tencent.com> <Yyz2x5bSR/7ZTV0R@google.com>
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On 23/9/2022 7:59 am, Sean Christopherson wrote:
> The bigger issue is that calling __kvm_perf_overflow() here can get false negatives.
> If reprogramming fails due to contention, the reprogram_pmi bit will be left set
> and so this check in __kvm_perf_overflow() will suppress the PMI.

I understand your motivation, and before we reprocess on "left set reprogram_pmi 
bit",
we may need reproducible cases to cover "reprogramming fails".