From 902caeb6841a64072791b1c18f9f56089566865d Mon Sep 17 00:00:00 2001 From: Like Xu Date: Mon, 11 Apr 2022 18:19:40 +0800 Subject: KVM: x86/pmu: Add PEBS_DATA_CFG MSR emulation to support adaptive PEBS 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 Signed-off-by: Luwei Kang Signed-off-by: Like Xu Message-Id: <20220411101946.20262-12-likexu@tencent.com> Signed-off-by: Paolo Bonzini --- arch/x86/events/intel/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/x86/events') diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index e5e624cae957..8f6189f2fbf3 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -4033,6 +4033,14 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data) .guest = kvm_pmu->ds_area, }; + if (x86_pmu.intel_cap.pebs_baseline) { + arr[(*nr)++] = (struct perf_guest_switch_msr){ + .msr = MSR_PEBS_DATA_CFG, + .host = cpuc->pebs_data_cfg, + .guest = kvm_pmu->pebs_data_cfg, + }; + } + pebs_enable = (*nr)++; arr[pebs_enable] = (struct perf_guest_switch_msr){ .msr = MSR_IA32_PEBS_ENABLE, -- cgit v1.2.3