KVM: Split IOAPIC reset function and export for kernel RESET

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/ioapic.c b/drivers/kvm/ioapic.c
index e14b7c7..cf1d50b 100644
--- a/drivers/kvm/ioapic.c
+++ b/drivers/kvm/ioapic.c
@@ -371,18 +371,27 @@
 	}
 }
 
+void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
+{
+	int i;
+
+	for (i = 0; i < IOAPIC_NUM_PINS; i++)
+		ioapic->redirtbl[i].fields.mask = 1;
+	ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
+	ioapic->ioregsel = 0;
+	ioapic->irr = 0;
+	ioapic->id = 0;
+}
+
 int kvm_ioapic_init(struct kvm *kvm)
 {
 	struct kvm_ioapic *ioapic;
-	int i;
 
 	ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
 	if (!ioapic)
 		return -ENOMEM;
 	kvm->vioapic = ioapic;
-	for (i = 0; i < IOAPIC_NUM_PINS; i++)
-		ioapic->redirtbl[i].fields.mask = 1;
-	ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
+	kvm_ioapic_reset(ioapic);
 	ioapic->dev.read = ioapic_mmio_read;
 	ioapic->dev.write = ioapic_mmio_write;
 	ioapic->dev.in_range = ioapic_in_range;
diff --git a/drivers/kvm/irq.h b/drivers/kvm/irq.h
index e08ae10..5ad3cfd 100644
--- a/drivers/kvm/irq.h
+++ b/drivers/kvm/irq.h
@@ -140,6 +140,7 @@
 int kvm_create_lapic(struct kvm_vcpu *vcpu);
 void kvm_lapic_reset(struct kvm_vcpu *vcpu);
 void kvm_pic_reset(struct kvm_kpic_state *s);
+void kvm_ioapic_reset(struct kvm_ioapic *ioapic);
 void kvm_free_lapic(struct kvm_vcpu *vcpu);
 u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu);
 void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8);