perf/x86/intel: Support PERF_PMU_CAP_MEDIATED_VPMU

Apply the PERF_PMU_CAP_MEDIATED_VPMU for Intel core PMU. It only indicates
that the perf side of core PMU is ready to support the mediated vPMU.
Besides the capability, the hypervisor, a.k.a. KVM, still needs to check
the PMU version and other PMU features/capabilities to decide whether to
enable support mediated vPMUs.

[sean: massage changelog]
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Xudong Hao <xudong.hao@intel.com>
Link: https://patch.msgid.link/20251206001720.468579-13-seanjc@google.com

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index bdf3f0d0fe216764cf39f611661cf2d03963af01..0553c1160f15b43486fed0db1d5d8b8f0eeb4153 100644 (file)
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -5695,6 +5695,8 @@ static void intel_pmu_check_hybrid_pmus(struct x86_hybrid_pmu *pmu)
        else
                pmu->intel_ctrl &= ~GLOBAL_CTRL_EN_PERF_METRICS;
 
+       pmu->pmu.capabilities |= PERF_PMU_CAP_MEDIATED_VPMU;
+
        intel_pmu_check_event_constraints_all(&pmu->pmu);
 
        intel_pmu_check_extra_regs(pmu->extra_regs);
@@ -7314,6 +7316,9 @@ __init int intel_pmu_init(void)
                        pr_cont(" AnyThread deprecated, ");
        }
 
+       /* The perf side of core PMU is ready to support the mediated vPMU. */
+       x86_get_pmu(smp_processor_id())->capabilities |= PERF_PMU_CAP_MEDIATED_VPMU;
+
        /*
         * Many features on and after V6 require dynamic constraint,
         * e.g., Arch PEBS, ACR.