[PATCH] KVM: x86: Silence various LAPIC-related host kernel messages

[Jan Kiszka <jan.kiszka@siemens.com>]

KVM-x86 dumps a lot of debug messages that have no meaning for normal
operation:
 - INIT de-assertion is ignored
 - SIPIs are sent and received
 - APIC writes are unaligned or < 4 byte long
   (Windows Server 2003 triggers this on SMP)

Degrade them to true debug messages, keeping the host kernel log clean
for real problems.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 arch/x86/kvm/lapic.c |   16 +++++++---------
 arch/x86/kvm/x86.c   |    4 ++--
 2 files changed, 9 insertions(+), 11 deletions(-)

Index: b/arch/x86/kvm/lapic.c
===================================================================
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -365,16 +365,14 @@ static int __apic_accept_irq(struct kvm_
 			vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
 			kvm_vcpu_kick(vcpu);
 		} else {
-			printk(KERN_DEBUG
-			       "Ignoring de-assert INIT to vcpu %d\n",
-			       vcpu->vcpu_id);
+			apic_debug("Ignoring de-assert INIT to vcpu %d\n",
+				   vcpu->vcpu_id);
 		}
-
 		break;
 
 	case APIC_DM_STARTUP:
-		printk(KERN_DEBUG "SIPI to vcpu %d vector 0x%02x\n",
-		       vcpu->vcpu_id, vector);
+		apic_debug("SIPI to vcpu %d vector 0x%02x\n",
+			   vcpu->vcpu_id, vector);
 		if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
 			vcpu->arch.sipi_vector = vector;
 			vcpu->arch.mp_state = KVM_MP_STATE_SIPI_RECEIVED;
@@ -679,9 +677,9 @@ static void apic_mmio_write(struct kvm_i
 	 * Refer SDM 8.4.1
 	 */
 	if (len != 4 || alignment) {
-		if (printk_ratelimit())
-			printk(KERN_ERR "apic write: bad size=%d %lx\n",
-			       len, (long)address);
+		/* Don't shout loud, $infamous_os would cause only noise. */
+		apic_debug("apic write: bad size=%d %lx\n",
+			   len, (long)address);
 		return;
 	}
 
Index: b/arch/x86/kvm/x86.c
===================================================================
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3224,8 +3224,8 @@ static int __vcpu_run(struct kvm_vcpu *v
 	int r;
 
 	if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_SIPI_RECEIVED)) {
-		printk("vcpu %d received sipi with vector # %x\n",
-		       vcpu->vcpu_id, vcpu->arch.sipi_vector);
+		pr_debug("vcpu %d received sipi with vector # %x\n",
+			 vcpu->vcpu_id, vcpu->arch.sipi_vector);
 		kvm_lapic_reset(vcpu);
 		r = kvm_x86_ops->vcpu_reset(vcpu);
 		if (r)