[kvm-unit-tests PATCH v3 08/13] x86/pmu: Add PDCM check before accessing PERF_CAP register

[Like Xu <like.xu.linux@xxxxxxxxx>]

From: Like Xu <likexu@xxxxxxxxxxx>

On virtual platforms without PDCM support (e.g. AMD), #GP
failure on MSR_IA32_PERF_CAPABILITIES is completely avoidable.

Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
---
 x86/pmu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/x86/pmu.c b/x86/pmu.c
index 4eb92d8..25fafbe 100644
--- a/x86/pmu.c
+++ b/x86/pmu.c
@@ -669,7 +669,8 @@ int main(int ac, char **av)
 
 	check_counters();
 
-	if (rdmsr(MSR_IA32_PERF_CAPABILITIES) & PMU_CAP_FW_WRITES) {
+	if (this_cpu_has(X86_FEATURE_PDCM) &&
+	    (rdmsr(MSR_IA32_PERF_CAPABILITIES) & PMU_CAP_FW_WRITES)) {
 		gp_counter_base = MSR_IA32_PMC0;
 		report_prefix_push("full-width writes");
 		check_counters();
-- 
2.37.2