diff --git a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c index 2feef25ba691..13eca9357252 100644 --- a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c +++ b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c @@ -100,6 +100,15 @@ static void check_msr(uint32_t msr, uint64_t bits_to_flip) GUEST_SYNC(0); } +static uint64_t run_and_measure_loop(uint32_t msr_base) +{ + uint64_t branches_retired = rdmsr(msr_base + 0); + + __asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES})); + + return rdmsr(msr_base + 0) - branches_retired; +} + static void intel_guest_code(void) { check_msr(MSR_CORE_PERF_GLOBAL_CTRL, 1); @@ -108,16 +117,15 @@ static void intel_guest_code(void) GUEST_SYNC(1); for (;;) { - uint64_t br0, br1; + uint64_t count; wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0); wrmsr(MSR_P6_EVNTSEL0, ARCH_PERFMON_EVENTSEL_ENABLE | ARCH_PERFMON_EVENTSEL_OS | INTEL_BR_RETIRED); - wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 1); - br0 = rdmsr(MSR_IA32_PMC0); - __asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES})); - br1 = rdmsr(MSR_IA32_PMC0); - GUEST_SYNC(br1 - br0); + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0x1); + + count = run_and_measure_loop(MSR_IA32_PMC0); + GUEST_SYNC(count); } } @@ -133,15 +141,14 @@ static void amd_guest_code(void) GUEST_SYNC(1); for (;;) { - uint64_t br0, br1; + uint64_t count; wrmsr(MSR_K7_EVNTSEL0, 0); wrmsr(MSR_K7_EVNTSEL0, ARCH_PERFMON_EVENTSEL_ENABLE | ARCH_PERFMON_EVENTSEL_OS | AMD_ZEN_BR_RETIRED); - br0 = rdmsr(MSR_K7_PERFCTR0); - __asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES})); - br1 = rdmsr(MSR_K7_PERFCTR0); - GUEST_SYNC(br1 - br0); + + count = run_and_measure_loop(MSR_K7_PERFCTR0); + GUEST_SYNC(count); } }