diff --git a/doc/developer-guides/hld/hv-io-emulation.rst b/doc/developer-guides/hld/hv-io-emulation.rst
index fccedf42e..9b674a9e9 100644
--- a/doc/developer-guides/hld/hv-io-emulation.rst
+++ b/doc/developer-guides/hld/hv-io-emulation.rst
@@ -310,9 +310,6 @@ The following structure represents a MMIO handler.
 The following APIs are provided to initialize, deinitialize or configure
 I/O bitmaps and register or unregister I/O handlers:
 
-.. doxygenfunction:: setup_io_bitmap
-   :project: Project ACRN
-
 .. doxygenfunction:: allow_guest_pio_access
    :project: Project ACRN
 
diff --git a/hypervisor/arch/x86/guest/vm.c b/hypervisor/arch/x86/guest/vm.c
index d3ad6a93a..f5fcb46f2 100644
--- a/hypervisor/arch/x86/guest/vm.c
+++ b/hypervisor/arch/x86/guest/vm.c
@@ -42,6 +42,21 @@ static inline bool is_vm_valid(uint16_t vm_id)
 	return bitmap_test(vm_id, &vmid_bitmap);
 }
 
+/**
+ * @brief Initialize the I/O bitmap for \p vm
+ *
+ * @param vm The VM whose I/O bitmap is to be initialized
+ */
+static void setup_io_bitmap(struct acrn_vm *vm)
+{
+	if (is_vm0(vm)) {
+		(void)memset(vm->arch_vm.io_bitmap, 0x00U, PAGE_SIZE * 2U);
+	} else {
+		/* block all IO port access from Guest */
+		(void)memset(vm->arch_vm.io_bitmap, 0xFFU, PAGE_SIZE * 2U);
+	}
+}
+
 /* return a pointer to the virtual machine structure associated with
  * this VM ID
  */
diff --git a/hypervisor/arch/x86/io_emul.c b/hypervisor/arch/x86/io_emul.c
index 165acb430..2d4ac857c 100644
--- a/hypervisor/arch/x86/io_emul.c
+++ b/hypervisor/arch/x86/io_emul.c
@@ -442,21 +442,6 @@ static void deny_guest_pio_access(struct acrn_vm *vm, uint16_t port_address,
 	}
 }
 
-/**
- * @brief Initialize the I/O bitmap for \p vm
- *
- * @param vm The VM whose I/O bitmap is to be initialized
- */
-void setup_io_bitmap(struct acrn_vm *vm)
-{
-	if (is_vm0(vm)) {
-		(void)memset(vm->arch_vm.io_bitmap, 0x00U, PAGE_SIZE * 2U);
-	} else {
-		/* block all IO port access from Guest */
-		(void)memset(vm->arch_vm.io_bitmap, 0xFFU, PAGE_SIZE * 2U);
-	}
-}
-
 /**
  * @brief Register a port I/O handler
  *
diff --git a/hypervisor/include/arch/x86/io_emul.h b/hypervisor/include/arch/x86/io_emul.h
index 5934a55e3..86086d47a 100644
--- a/hypervisor/include/arch/x86/io_emul.h
+++ b/hypervisor/include/arch/x86/io_emul.h
@@ -91,13 +91,6 @@ int32_t pio_instr_vmexit_handler(struct acrn_vcpu *vcpu);
  */
 void   allow_guest_pio_access(struct acrn_vm *vm, uint16_t port_address, uint32_t nbytes);
 
-/**
- * @brief Initialize the I/O bitmap for \p vm
- *
- * @param vm The VM whose I/O bitmap is to be initialized
- */
-void setup_io_bitmap(struct acrn_vm *vm);
-
 /**
  * @brief Register a port I/O handler
  *