KVM: Introduce kvm_vcpu_is_bsp() function.

Use it instead of open code "vcpu_id zero is BSP" assumption.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

virt/kvm/ioapic.c

@@ -164,7 +164,9 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
 	/* Always delivery PIT interrupt to vcpu 0 */
 	if (irq == 0) {
 		irqe.dest_mode = 0; /* Physical mode. */
-		irqe.dest_id = ioapic->kvm->vcpus[0]->vcpu_id;
+		/* need to read apic_id from apic regiest since
+		 * it can be rewritten */
+		irqe.dest_id = ioapic->kvm->bsp_vcpu->vcpu_id;
 	}
 #endif
 	return kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe);

virt/kvm/kvm_main.c

@@ -1747,6 +1747,8 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 		goto vcpu_destroy;
 	}
 	kvm->vcpus[n] = vcpu;
+	if (n == 0)
+		kvm->bsp_vcpu = vcpu;
 	mutex_unlock(&kvm->lock);
 
 	/* Now it's all set up, let userspace reach it */