diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 2b5db464c7aa..90414c59f0be 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1275,6 +1275,9 @@ void kvm_apic_send_ipi(struct kvm_lapic *apic, u32 icr_low, u32 icr_high)
 {
 	struct kvm_lapic_irq irq;
 
+	/* KVM has no delay and should always clear the BUSY/PENDING flag. */
+	WARN_ON_ONCE(icr_low & APIC_ICR_BUSY);
+
 	irq.vector = icr_low & APIC_VECTOR_MASK;
 	irq.delivery_mode = icr_low & APIC_MODE_MASK;
 	irq.dest_mode = icr_low & APIC_DEST_MASK;
@@ -2053,7 +2056,7 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
 	}
 	case APIC_ICR:
 		/* No delay here, so we always clear the pending bit */
-		val &= ~(1 << 12);
+		val &= ~APIC_ICR_BUSY;
 		kvm_apic_send_ipi(apic, val, kvm_lapic_get_reg(apic, APIC_ICR2));
 		kvm_lapic_set_reg(apic, APIC_ICR, val);
 		break;
@@ -2131,6 +2134,11 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
 		break;
 	}
 
+	/*
+	 * Recalculate APIC maps if necessary, e.g. if the software enable bit
+	 * was toggled, the APIC ID changed, etc...   The maps are marked dirty
+	 * on relevant changes, i.e. this is a nop for most writes.
+	 */
 	kvm_recalculate_apic_map(apic->vcpu->kvm);
 
 	return ret;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d226012f849f..7a8e8756c016 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2039,11 +2039,10 @@ static int handle_fastpath_set_x2apic_icr_irqoff(struct kvm_vcpu *vcpu, u64 data
 		return 1;
 
 	if (((data & APIC_SHORT_MASK) == APIC_DEST_NOSHORT) &&
-		((data & APIC_DEST_MASK) == APIC_DEST_PHYSICAL) &&
-		((data & APIC_MODE_MASK) == APIC_DM_FIXED) &&
-		((u32)(data >> 32) != X2APIC_BROADCAST)) {
-
-		data &= ~(1 << 12);
+	    ((data & APIC_DEST_MASK) == APIC_DEST_PHYSICAL) &&
+	    ((data & APIC_MODE_MASK) == APIC_DM_FIXED) &&
+	    ((u32)(data >> 32) != X2APIC_BROADCAST)) {
+		data &= ~APIC_ICR_BUSY;
 		kvm_apic_send_ipi(vcpu->arch.apic, (u32)data, (u32)(data >> 32));
 		kvm_lapic_set_reg(vcpu->arch.apic, APIC_ICR2, (u32)(data >> 32));
 		kvm_lapic_set_reg(vcpu->arch.apic, APIC_ICR, (u32)data);