Messages in this thread | | | Date | Thu, 6 Apr 2023 16:59:00 -0700 | Subject | Re: [PATCH v4 07/12] KVM: x86/cpuid: Use fast return for cpuid "0xa" leaf when !enable_pmu | From | Sean Christopherson <> |
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KVM: x86: Explicitly zero cpuid "0xa" leaf when PMU is disabled
On Tue, Feb 14, 2023, Like Xu wrote: > From: Like Xu <likexu@tencent.com> > > Add an explicit !enable_pmu check as relying on kvm_pmu_cap to be > zeroed isn't obvious. Although when !enable_pmu, KVM will have > zero-padded kvm_pmu_cap to do subsequent cpuid leaf assignments, > one extra branch instruction saves a few subsequent zero-assignment > instructions, speeding things up a bit.
Drop the performance blurb, as I stated multiple times, optimizing this code is a non-goal.
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