diff options
| -rw-r--r-- | arch/x86/kvm/pmu.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 02f9e4f245bd..390d697efde1 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -106,9 +106,19 @@ static inline void __kvm_perf_overflow(struct kvm_pmc *pmc, bool in_pmi) return; if (pmc->perf_event && pmc->perf_event->attr.precise_ip) { - /* Indicate PEBS overflow PMI to guest. */ - skip_pmi = __test_and_set_bit(GLOBAL_STATUS_BUFFER_OVF_BIT, - (unsigned long *)&pmu->global_status); + if (!in_pmi) { + /* + * TODO: KVM is currently _choosing_ to not generate records + * for emulated instructions, avoiding BUFFER_OVF PMI when + * there are no records. Strictly speaking, it should be done + * as well in the right context to improve sampling accuracy. + */ + skip_pmi = true; + } else { + /* Indicate PEBS overflow PMI to guest. */ + skip_pmi = __test_and_set_bit(GLOBAL_STATUS_BUFFER_OVF_BIT, + (unsigned long *)&pmu->global_status); + } } else { __set_bit(pmc->idx, (unsigned long *)&pmu->global_status); } |