When load KVM module in Intel hybrid platforms, the warning below is observed. <4>[ 10.973827] ------------[ cut here ]------------ <4>[ 10.973841] WARNING: arch/x86/events/core.c:3089 at perf_get_x86_pmu_capability+0xd/0xc0, CPU#15: (udev-worker)/386 ... <4>[ 10.974028] Call Trace: <4>[ 10.974030] <4>[ 10.974033] ? kvm_init_pmu_capability+0x2b/0x190 [kvm] <4>[ 10.974154] kvm_x86_vendor_init+0x1b0/0x1a40 [kvm] <4>[ 10.974248] vmx_init+0xdb/0x260 [kvm_intel] <4>[ 10.974278] ? __pfx_vt_init+0x10/0x10 [kvm_intel] <4>[ 10.974296] vt_init+0x12/0x9d0 [kvm_intel] <4>[ 10.974309] ? __pfx_vt_init+0x10/0x10 [kvm_intel] <4>[ 10.974322] do_one_initcall+0x60/0x3f0 <4>[ 10.974335] do_init_module+0x97/0x2b0 <4>[ 10.974345] load_module+0x2d08/0x2e30 <4>[ 10.974349] ? __kernel_read+0x158/0x2f0 <4>[ 10.974370] ? kernel_read_file+0x2b1/0x320 <4>[ 10.974381] init_module_from_file+0x96/0xe0 <4>[ 10.974384] ? init_module_from_file+0x96/0xe0 <4>[ 10.974399] idempotent_init_module+0x117/0x330 <4>[ 10.974415] __x64_sys_finit_module+0x73/0xe0 The root cause is the helper perf_get_x86_pmu_capability() is called unconditionally but it's supposed to be called only on non-hybrid platforms. This patch fixes this warning by only calling perf_get_x86_pmu_capability() on non-hybrid platforms. Reported-by: Chaitanya Kumar Borah Closes: https://lore.kernel.org/all/70b64347-2aca-4511-af78-a767d5fa8226@intel.com/ Fixes: 51f34b1e650f ("KVM: x86/pmu: Snapshot host (i.e. perf's) reported PMU capabilities") Suggested-by: Sean Christopherson Signed-off-by: Dapeng Mi --- arch/x86/kvm/pmu.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 40ac4cb44ed2..487ad19a236e 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -108,16 +108,18 @@ void kvm_init_pmu_capability(const struct kvm_pmu_ops *pmu_ops) bool is_intel = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL; int min_nr_gp_ctrs = pmu_ops->MIN_NR_GP_COUNTERS; - perf_get_x86_pmu_capability(&kvm_host_pmu); - /* * Hybrid PMUs don't play nice with virtualization without careful * configuration by userspace, and KVM's APIs for reporting supported * vPMU features do not account for hybrid PMUs. Disable vPMU support * for hybrid PMUs until KVM gains a way to let userspace opt-in. */ - if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) + if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) { enable_pmu = false; + memset(&kvm_host_pmu, 0, sizeof(kvm_host_pmu)); + } else { + perf_get_x86_pmu_capability(&kvm_host_pmu); + } if (enable_pmu) { /* -- 2.34.1