From: Jinrong Liang <cloudliang@xxxxxxxxxxx>
Update test to cover Intel PMU architectural events on fixed counters.
Per Intel SDM, PMU users can also count architecture performance events
on fixed counters (specifically, FIXED_CTR0 for the retired instructions
and FIXED_CTR1 for cpu core cycles event). Therefore, if guest's CPUID
indicates that an architecture event is not available, the corresponding
fixed counter will also not count that event.
Co-developed-by: Like Xu <likexu@xxxxxxxxxxx>
Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
Signed-off-by: Jinrong Liang <cloudliang@xxxxxxxxxxx>
---
.../kvm/x86_64/pmu_basic_functionality_test.c | 21 +++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c b/tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c
index c04eb0bdf69f..daa45aa285bb 100644
--- a/tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c
+++ b/tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c
@@ -47,6 +47,7 @@ static uint64_t run_vcpu(struct kvm_vcpu *vcpu, uint64_t *ucall_arg)
static void guest_measure_loop(uint64_t event_code)
{
+ uint32_t nr_fixed_counter = this_cpu_property(X86_PROPERTY_PMU_NR_FIXED_COUNTERS);
uint32_t nr_gp_counters = this_cpu_property(X86_PROPERTY_PMU_NR_GP_COUNTERS);
uint32_t pmu_version = this_cpu_property(X86_PROPERTY_PMU_VERSION);
uint32_t counter_msr;
@@ -73,6 +74,26 @@ static void guest_measure_loop(uint64_t event_code)
}
}
+ if (pmu_version < 2 || nr_fixed_counter < 1)
+ goto done;
+
+ if (event_code == intel_arch_events[INTEL_ARCH_INSTRUCTIONS_RETIRED])
+ i = 0;
+ else if (event_code == intel_arch_events[INTEL_ARCH_CPU_CYCLES])
+ i = 1;
+ else
+ goto done;
+
+ wrmsr(MSR_CORE_PERF_FIXED_CTR0 + i, 0);
+ wrmsr(MSR_CORE_PERF_FIXED_CTR_CTRL, BIT_ULL(4 * i));
+ wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, BIT_ULL(INTEL_PMC_IDX_FIXED + i));
+
+ __asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES}));
+
+ wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0);
+ GUEST_SYNC(_rdpmc(RDPMC_FIXED_BASE | i));
+
+done:
GUEST_DONE();
}
--
2.39.3
