From: Like Xu like.xu@linux.intel.com
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 joe@perches.com Signed-off-by: Like Xu like.xu@linux.intel.com Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kvm/pmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -128,8 +128,8 @@ static void pmc_reprogram_counter(struct 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; }