[kvm-unit-tests PATCH 2/3] x86: Skip running test when pmu is disabled

[Yang Weijiang <weijiang.yang@intel.com>]

Read MSR_IA32_PERF_CAPABILITIES triggers #GP when pmu is disabled
by enable_pmu=0 in KVM. Let's check whether pmu is available before
issue msr reading to avoid the #GP.

Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
 x86/pmu_lbr.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/x86/pmu_lbr.c b/x86/pmu_lbr.c
index 688634d..835a7bb 100644
--- a/x86/pmu_lbr.c
+++ b/x86/pmu_lbr.c
@@ -74,13 +74,15 @@ int main(int ac, char **av)
 		return 0;
 	}
 
-	perf_cap = rdmsr(MSR_IA32_PERF_CAPABILITIES);
 	eax.full = id.a;
 
 	if (!eax.split.version_id) {
 		printf("No pmu is detected!\n");
 		return report_summary();
 	}
+
+	perf_cap = rdmsr(MSR_IA32_PERF_CAPABILITIES);
+
 	if (!(perf_cap & PMU_CAP_LBR_FMT)) {
 		printf("No LBR is detected!\n");
 		return report_summary();
-- 
2.31.1