Re: [PATCH v2 4/4] KVM: x86/vPMU: Add lazy mechanism to release perf_event per vPMC
From: Paolo Bonzini
Date: Mon Oct 21 2019 - 11:28:37 EST
On 21/10/19 16:04, Like Xu wrote:
>> 2) introduce a new callback msr_idx_to_pmc that returns a struct
>> kvm_pmc*, and change kvm_pmu_is_valid_msr to do
> For callback msr_idx_to_pmc,
> how do we deal with the input 'MSR_CORE_PERF_FIXED_CTR_CTRL'
> which may return several fixed kvm_pmcs not just one?
For RDMSR, do not do anything. For WRMSR, you can handle it in the
>> static int kvm_pmu_mark_pmc_in_use(struct kvm_vcpu *vcpu, u32 msr)
> s/static int/static void/.
>> struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
>> struct kvm_pmc *pmc = kvm_x86_ops->pmu_ops->msr_idx_to_pmc(vcpu, msr);
> We need 'if(pmc)' here.
Agreed, sorry for the sloppiness. Never interpret my suggestions as
more than pseudocode. :)