On Thu, May 14, 2020 at 04:30:48PM +0800, Like Xu wrote: > @@ -544,7 +562,12 @@ void intel_pmu_lbr_enable_all(bool pmi) > { > struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); > > - if (cpuc->lbr_users) > + /* > + * When the LBR hardware is scheduled for a guest LBR event, > + * the guest will dis/enables LBR itself at the appropriate time, > + * including configuring MSR_LBR_SELECT. > + */ > + if (cpuc->lbr_users && !cpuc->guest_lbr_enabled) > __intel_pmu_lbr_enable(pmi); > } No!, that should be done through perf_event_attr::exclude_host, as I believe all the other KVM event do it.