KVM: x86: Eliminate log spam from limited APIC timer periods

SAP's vSMP MemoryONE continuously requests a local APIC timer period
less than 500 us, resulting in the following kernel log spam:

  kvm: vcpu 15: requested 70240 ns lapic timer period limited to 500000 ns
  kvm: vcpu 19: requested 52848 ns lapic timer period limited to 500000 ns
  kvm: vcpu 15: requested 70256 ns lapic timer period limited to 500000 ns
  kvm: vcpu 9: requested 70256 ns lapic timer period limited to 500000 ns
  kvm: vcpu 9: requested 70208 ns lapic timer period limited to 500000 ns
  kvm: vcpu 9: requested 387520 ns lapic timer period limited to 500000 ns
  kvm: vcpu 9: requested 70160 ns lapic timer period limited to 500000 ns
  kvm: vcpu 66: requested 205744 ns lapic timer period limited to 500000 ns
  kvm: vcpu 9: requested 70224 ns lapic timer period limited to 500000 ns
  kvm: vcpu 9: requested 70256 ns lapic timer period limited to 500000 ns
  limit_periodic_timer_frequency: 7569 callbacks suppressed
  ...

To eliminate this spam, change the pr_info_ratelimited() in
limit_periodic_timer_frequency() to pr_info_once().

Reported-by: James Houghton <jthoughton@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Message-ID: <20240724190640.2449291-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index a7172ba59ad2e7e95ae3c63f337310e8aa6cb083..4915acdbfcd8d9808545ae45eccde829cc376919 100644 (file)
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1743,7 +1743,7 @@ static void limit_periodic_timer_frequency(struct kvm_lapic *apic)
                s64 min_period = min_timer_period_us * 1000LL;
 
                if (apic->lapic_timer.period < min_period) {
-                       pr_info_ratelimited(
+                       pr_info_once(
                            "vcpu %i: requested %lld ns "
                            "lapic timer period limited to %lld ns\n",
                            apic->vcpu->vcpu_id,