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Like Xu authored
If IA32_PERF_CAPABILITIES.PEBS_BASELINE [bit 14] is set, the adaptive PEBS is supported. The PEBS_DATA_CFG MSR and adaptive record enable bits (IA32_PERFEVTSELx.Adaptive_Record and IA32_FIXED_CTR_CTRL. FCx_Adaptive_Record) are also supported. Adaptive PEBS provides software the capability to configure the PEBS records to capture only the data of interest, keeping the record size compact. An overflow of PMCx results in generation of an adaptive PEBS record with state information based on the selections specified in MSR_PEBS_DATA_CFG.By default, the record only contain the Basic group. When guest adaptive PEBS is enabled, the IA32_PEBS_ENABLE MSR will be added to the perf_guest_switch_msr() and switched during the VMX transitions just like CORE_PERF_GLOBAL_CTRL MSR. According to Intel SDM, software is recommended to PEBS Baseline when the following is true. IA32_PERF_CAPABILITIES.PEBS_BASELINE[14] && IA32_PERF_CAPABILITIES.PEBS_FMT[11:8] ≥ 4. Co-developed-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Like Xu <likexu@tencent.com> Message-Id: <20220411101946.20262-12-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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