The entry address for a VM is an IPA.

Change-Id: I9b447796789082c031c8a342a283d3050cf15ccb
diff --git a/src/vm.c b/src/vm.c
index 66be66e..d2da22e 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -22,7 +22,7 @@
 }
 
 /* TODO: Shall we use index or id here? */
-void vm_start_vcpu(struct vm *vm, size_t index, size_t entry, size_t arg,
+void vm_start_vcpu(struct vm *vm, size_t index, ipaddr_t entry, size_t arg,
 		   bool is_primary)
 {
 	struct vcpu *vcpu = vm->vcpus + index;