Messages in this thread Patch in this message | | | Date | Tue, 27 Dec 2022 10:18:12 +0800 | Subject | Re: [PATCH 1/3] KVM: x86: Omit PMU MSRs from KVM_GET_MSR_INDEX_LIST if !enable_pmu | From | "Yang, Weijiang" <> |
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On 12/27/2022 8:59 AM, Yang, Weijiang wrote: > On 12/26/2022 7:17 PM, Like Xu wrote: >> From: Like Xu <likexu@tencent.com> >> >> When the PMU is disabled, don't bother sharing the PMU MSRs with >> userspace through KVM_GET_MSR_INDEX_LIST. Instead, filter them out >> so userspace doesn't have to keep track of them. >> >> Note that 'enable_pmu' is read-only, so userspace has no control over >> whether the PMU MSRs are included in the list or not.
[...]
>> + case MSR_ARCH_PERFMON_FIXED_CTR0 ... MSR_ARCH_PERFMON_FIXED_CTR_MAX: >> + if (!enable_pmu || msrs_to_save_all[i] - MSR_ARCH_PERFMON_FIXED_CTR0 >= >> + min(KVM_PMC_MAX_FIXED, kvm_pmu_cap.num_counters_fixed)) >> + continue; >> + break; >> + case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5: >> + case MSR_K7_EVNTSEL0 ... MSR_K7_PERFCTR3: >> + case MSR_CORE_PERF_FIXED_CTR_CTRL: >> + case MSR_CORE_PERF_GLOBAL_STATUS: >> + case MSR_CORE_PERF_GLOBAL_CTRL: >> + case MSR_CORE_PERF_GLOBAL_OVF_CTRL: >> + case MSR_IA32_DS_AREA: >> + case MSR_IA32_PEBS_ENABLE: >> + case MSR_PEBS_DATA_CFG: >> + if (!enable_pmu) >> + continue; >> + break; > > I prefer use a helper to wrap the hunk of PMU msr checks and move the > helper to > > the "default" branch of switch, it makes the code looks nicer: > > default: > > if(!enable_pmu && !kvm_pmu_valid_msrlist(msr))
Typo, should be:
if (!enable_pmu || !kvm_pmu_valid_msrlist(msr))
> > continue; > > >> case MSR_IA32_XFD: >> case MSR_IA32_XFD_ERR: >> if (!kvm_cpu_cap_has(X86_FEATURE_XFD)) >> @@ -13468,3 +13485,4 @@ static void __exit kvm_x86_exit(void) >> */ >> } >> module_exit(kvm_x86_exit); >> + > > Extra newline. > > >
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