diff --git a/driver/linux b/driver/linux
index 39bf789..6aef655 160000
--- a/driver/linux
+++ b/driver/linux
@@ -1 +1 @@
-Subproject commit 39bf7898ab02d0cda2de33c03838b4ee131b4f65
+Subproject commit 6aef655db80434c776f49ade53d7bf8673b8109a
diff --git a/inc/vmapi/hf/abi.h b/inc/vmapi/hf/abi.h
index 9423442..bdb6705 100644
--- a/inc/vmapi/hf/abi.h
+++ b/inc/vmapi/hf/abi.h
@@ -62,13 +62,3 @@
 	 */
 	HF_MEMORY_SHARE,
 };
-
-static inline spci_vm_id_t wake_up_get_vm_id(struct spci_value v)
-{
-	return v.arg1 & 0xffff;
-}
-
-static inline spci_vcpu_index_t wake_up_get_vcpu(struct spci_value v)
-{
-	return (v.arg1 >> 16) & 0xffff;
-}
diff --git a/inc/vmapi/hf/call.h b/inc/vmapi/hf/call.h
index 94f70e8..d446754 100644
--- a/inc/vmapi/hf/call.h
+++ b/inc/vmapi/hf/call.h
@@ -66,7 +66,7 @@
 					 spci_vcpu_index_t vcpu_idx)
 {
 	return spci_call((struct spci_value){.func = SPCI_RUN_32,
-					     (uint32_t)vm_id << 16 | vcpu_idx});
+					     spci_vm_vcpu(vm_id, vcpu_idx)});
 }
 
 /**
diff --git a/inc/vmapi/hf/spci.h b/inc/vmapi/hf/spci.h
index d5d55ff..fe8e7df 100644
--- a/inc/vmapi/hf/spci.h
+++ b/inc/vmapi/hf/spci.h
@@ -207,6 +207,22 @@
 	return args.arg4;
 }
 
+static inline spci_vm_id_t spci_vm_id(struct spci_value args)
+{
+	return (args.arg1 >> 16) & 0xffff;
+}
+
+static inline spci_vcpu_index_t spci_vcpu_index(struct spci_value args)
+{
+	return args.arg1 & 0xffff;
+}
+
+static inline uint64_t spci_vm_vcpu(spci_vm_id_t vm_id,
+				    spci_vcpu_index_t vcpu_index)
+{
+	return ((uint32_t)vm_id << 16) | vcpu_index;
+}
+
 struct spci_architected_message_header {
 	uint16_t type;
 
diff --git a/src/api.c b/src/api.c
index 7a16436..d73afb2 100644
--- a/src/api.c
+++ b/src/api.c
@@ -125,7 +125,7 @@
 {
 	struct spci_value ret = {
 		.func = SPCI_INTERRUPT_32,
-		.arg1 = ((uint32_t)current->vm->id << 16) | vcpu_index(current),
+		.arg1 = spci_vm_vcpu(current->vm->id, vcpu_index(current)),
 	};
 
 	return api_switch_to_primary(current, ret, VCPU_STATE_READY);
@@ -139,7 +139,7 @@
 {
 	struct spci_value ret = {
 		.func = HF_SPCI_RUN_WAIT_FOR_INTERRUPT,
-		.arg1 = ((uint32_t)vcpu_index(current) << 16) | current->vm->id,
+		.arg1 = spci_vm_vcpu(current->vm->id, vcpu_index(current)),
 	};
 
 	return api_switch_to_primary(current, ret,
@@ -153,7 +153,7 @@
 {
 	struct spci_value ret = {
 		.func = HF_SPCI_RUN_WAIT_FOR_INTERRUPT,
-		.arg1 = ((uint32_t)vcpu_index(current) << 16) | current->vm->id,
+		.arg1 = spci_vm_vcpu(current->vm->id, vcpu_index(current)),
 	};
 
 	/*
@@ -174,7 +174,7 @@
 {
 	struct spci_value primary_ret = {
 		.func = SPCI_YIELD_32,
-		.arg1 = ((uint32_t)vcpu_index(current) << 16) | current->vm->id,
+		.arg1 = spci_vm_vcpu(current->vm->id, vcpu_index(current)),
 	};
 
 	if (current->vm->id == HF_PRIMARY_VM_ID) {
@@ -193,8 +193,8 @@
 {
 	struct spci_value ret = {
 		.func = HF_SPCI_RUN_WAKE_UP,
-		.arg1 = ((uint32_t)vcpu_index(target_vcpu) << 16) |
-			target_vcpu->vm->id,
+		.arg1 = spci_vm_vcpu(target_vcpu->vm->id,
+				     vcpu_index(target_vcpu)),
 	};
 	return api_switch_to_primary(current, ret, VCPU_STATE_READY);
 }
@@ -485,8 +485,8 @@
 				vcpu->state == VCPU_STATE_BLOCKED_MAILBOX
 					? SPCI_MSG_WAIT_32
 					: HF_SPCI_RUN_WAIT_FOR_INTERRUPT;
-			run_ret->arg1 = ((uint32_t)vcpu_index(vcpu) << 16) |
-					vcpu->vm->id;
+			run_ret->arg1 =
+				spci_vm_vcpu(vcpu->vm->id, vcpu_index(vcpu));
 			run_ret->arg2 = timer_remaining_ns;
 		}
 
@@ -583,7 +583,7 @@
 	 * overwritten when the switch back to the primary occurs.
 	 */
 	ret.func = SPCI_INTERRUPT_32;
-	ret.arg1 = ((uint32_t)vm_id << 16) | vcpu_idx;
+	ret.arg1 = spci_vm_vcpu(vm_id, vcpu_idx);
 	ret.arg2 = 0;
 
 out:
@@ -1134,7 +1134,7 @@
 	{
 		struct spci_value run_return = {
 			.func = SPCI_MSG_WAIT_32,
-			.arg1 = ((uint32_t)vcpu_index(current) << 16) | vm->id,
+			.arg1 = spci_vm_vcpu(vm->id, vcpu_index(current)),
 		};
 
 		*next = api_switch_to_primary(current, run_return,
diff --git a/src/arch/aarch64/hypervisor/handler.c b/src/arch/aarch64/hypervisor/handler.c
index f976eee..1125dcf 100644
--- a/src/arch/aarch64/hypervisor/handler.c
+++ b/src/arch/aarch64/hypervisor/handler.c
@@ -345,8 +345,8 @@
 		*args = api_spci_msg_recv(false, current(), next);
 		return true;
 	case SPCI_RUN_32:
-		*args = api_spci_run((args->arg1 >> 16) & 0xffff,
-				     args->arg1 & 0xffff, current(), next);
+		*args = api_spci_run(spci_vm_id(*args), spci_vcpu_index(*args),
+				     current(), next);
 		return true;
 	}
 
diff --git a/test/vmapi/primary_with_secondaries/smp.c b/test/vmapi/primary_with_secondaries/smp.c
index 5ffda15..e0f9c46 100644
--- a/test/vmapi/primary_with_secondaries/smp.c
+++ b/test/vmapi/primary_with_secondaries/smp.c
@@ -40,8 +40,8 @@
 	/* Let the first vCPU start the second vCPU. */
 	run_res = spci_run(SERVICE_VM2, 0);
 	EXPECT_EQ(run_res.func, HF_SPCI_RUN_WAKE_UP);
-	EXPECT_EQ(wake_up_get_vm_id(run_res), SERVICE_VM2);
-	EXPECT_EQ(wake_up_get_vcpu(run_res), 1);
+	EXPECT_EQ(spci_vm_id(run_res), SERVICE_VM2);
+	EXPECT_EQ(spci_vcpu_index(run_res), 1);
 
 	/* Run the second vCPU and wait for a message. */
 	dlog("Run second vCPU for message\n");