KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed

commit 6fc3977ccc5d3c22e851f2dce2d3ce2a0a843842 upstream. If a perf_event creation fails due to any reason of the host perf subsystem, it has no chance to log the corresponding event for guest which may cause abnormal sampling data in guest result. In debug mode, this message helps to understand the state of vPMC and we may not limit the number of occurrences but not in a spamming style. Suggested-by: Joe Perches <[email protected]> Signed-off-by: Like Xu <[email protected]> Cc: [email protected] Signed-off-by: Paolo Bonzini <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
akeromi · Jul 26, 2019 · ba27a25 · ba27a25
1 parent 87bae91
commit ba27a25
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
@@ -131,8 +131,8 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
 						 intr ? kvm_perf_overflow_intr :
 						 kvm_perf_overflow, pmc);
 	if (IS_ERR(event)) {
-		printk_once("kvm_pmu: event creation failed %ld\n",
-			    PTR_ERR(event));
+		pr_debug_ratelimited("kvm_pmu: event creation failed %ld for pmc->idx = %d\n",
+			    PTR_ERR(event), pmc->idx);
 		return;
 	}