diff --git a/hypervisor/arch/x86/guest/vmcall.c b/hypervisor/arch/x86/guest/vmcall.c
index bd06d4ff5..9226e06e6 100644
--- a/hypervisor/arch/x86/guest/vmcall.c
+++ b/hypervisor/arch/x86/guest/vmcall.c
@@ -14,7 +14,7 @@
  */
 int vmcall_vmexit_handler(struct vcpu *vcpu)
 {
-	int64_t ret = -EACCES;
+	int32_t ret = -EACCES;
 	struct vm *vm = vcpu->vm;
 	struct run_context *cur_context =
 		&vcpu->arch_vcpu.contexts[vcpu->arch_vcpu.cur_context];
diff --git a/hypervisor/common/hypercall.c b/hypervisor/common/hypercall.c
index 9d2eec1e0..badcb0d02 100644
--- a/hypervisor/common/hypercall.c
+++ b/hypervisor/common/hypercall.c
@@ -25,7 +25,7 @@ bool is_hypercall_from_ring0(void)
 	return false;
 }
 
-int64_t hcall_get_api_version(struct vm *vm, uint64_t param)
+int32_t hcall_get_api_version(struct vm *vm, uint64_t param)
 {
 	struct hc_api_version version;
 
@@ -44,7 +44,8 @@ int64_t hcall_get_api_version(struct vm *vm, uint64_t param)
 	return 0;
 }
 
-static int handle_vpic_irqline(struct vm *vm, uint32_t irq, enum irq_mode mode)
+static int32_t
+handle_vpic_irqline(struct vm *vm, uint32_t irq, enum irq_mode mode)
 {
 	int32_t ret = -1;
 
@@ -68,7 +69,7 @@ static int handle_vpic_irqline(struct vm *vm, uint32_t irq, enum irq_mode mode)
 	return ret;
 }
 
-static int
+static int32_t
 handle_vioapic_irqline(struct vm *vm, uint32_t irq, enum irq_mode mode)
 {
 	int32_t ret = -1;
@@ -93,7 +94,8 @@ handle_vioapic_irqline(struct vm *vm, uint32_t irq, enum irq_mode mode)
 	return ret;
 }
 
-static int handle_virt_irqline(struct vm *vm, uint16_t target_vmid,
+static int32_t
+handle_virt_irqline(struct vm *vm, uint16_t target_vmid,
 		struct acrn_irqline *param, enum irq_mode mode)
 {
 	int32_t ret = 0;
@@ -131,9 +133,9 @@ static int handle_virt_irqline(struct vm *vm, uint16_t target_vmid,
 	return ret;
 }
 
-int64_t hcall_create_vm(struct vm *vm, uint64_t param)
+int32_t hcall_create_vm(struct vm *vm, uint64_t param)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	struct vm *target_vm = NULL;
 	/* VM are created from hv_main() directly
 	 * Here we just return the vmid for DM
@@ -170,9 +172,9 @@ int64_t hcall_create_vm(struct vm *vm, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_destroy_vm(uint64_t vmid)
+int32_t hcall_destroy_vm(uint64_t vmid)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	struct vm *target_vm = get_vm_from_vmid(vmid);
 
 	if (target_vm == NULL) {
@@ -183,9 +185,9 @@ int64_t hcall_destroy_vm(uint64_t vmid)
 	return ret;
 }
 
-int64_t hcall_resume_vm(uint64_t vmid)
+int32_t hcall_resume_vm(uint64_t vmid)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	struct vm *target_vm = get_vm_from_vmid(vmid);
 
 	if (target_vm == NULL) {
@@ -200,7 +202,7 @@ int64_t hcall_resume_vm(uint64_t vmid)
 	return ret;
 }
 
-int64_t hcall_pause_vm(uint64_t vmid)
+int32_t hcall_pause_vm(uint64_t vmid)
 {
 	struct vm *target_vm = get_vm_from_vmid(vmid);
 
@@ -213,7 +215,7 @@ int64_t hcall_pause_vm(uint64_t vmid)
 	return 0;
 }
 
-int64_t hcall_create_vcpu(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_create_vcpu(struct vm *vm, uint64_t vmid, uint64_t param)
 {
 	int32_t ret;
 	uint16_t pcpu_id;
@@ -240,9 +242,9 @@ int64_t hcall_create_vcpu(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_assert_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_assert_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	struct acrn_irqline irqline;
 
 	if (copy_from_gpa(vm, &irqline, param, sizeof(irqline)) != 0) {
@@ -254,9 +256,9 @@ int64_t hcall_assert_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_deassert_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_deassert_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	struct acrn_irqline irqline;
 
 	if (copy_from_gpa(vm, &irqline, param, sizeof(irqline)) != 0) {
@@ -268,9 +270,9 @@ int64_t hcall_deassert_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_pulse_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_pulse_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	struct acrn_irqline irqline;
 
 	if (copy_from_gpa(vm, &irqline, param, sizeof(irqline)) != 0) {
@@ -282,7 +284,7 @@ int64_t hcall_pulse_irqline(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_inject_msi(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_inject_msi(struct vm *vm, uint64_t vmid, uint64_t param)
 {
 	int32_t ret = 0;
 	struct acrn_msi_entry msi;
@@ -302,9 +304,9 @@ int64_t hcall_inject_msi(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_set_ioreq_buffer(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_set_ioreq_buffer(struct vm *vm, uint64_t vmid, uint64_t param)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	uint64_t hpa = 0UL;
 	struct acrn_set_ioreq_buffer iobuf;
 	struct vm *target_vm = get_vm_from_vmid(vmid);
@@ -368,7 +370,7 @@ static void complete_request(struct vcpu *vcpu)
 	resume_vcpu(vcpu);
 }
 
-int64_t hcall_notify_req_finish(uint64_t vmid, uint64_t vcpu_id)
+int32_t hcall_notify_req_finish(uint64_t vmid, uint64_t vcpu_id)
 {
 	union vhm_request_buffer *req_buf;
 	struct vhm_request *req;
@@ -403,7 +405,8 @@ int64_t hcall_notify_req_finish(uint64_t vmid, uint64_t vcpu_id)
 	return 0;
 }
 
-static int64_t _set_vm_memmap(struct vm *vm, struct vm *target_vm,
+static int32_t
+_set_vm_memmap(struct vm *vm, struct vm *target_vm,
 	struct vm_set_memmap *memmap)
 {
 	uint64_t hpa, base_paddr;
@@ -459,7 +462,7 @@ static int64_t _set_vm_memmap(struct vm *vm, struct vm *target_vm,
 		memmap->remote_gpa, memmap->length, memmap->type, attr);
 }
 
-int64_t hcall_set_vm_memmap(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_set_vm_memmap(struct vm *vm, uint64_t vmid, uint64_t param)
 {
 	struct vm_set_memmap memmap;
 	struct vm *target_vm = get_vm_from_vmid(vmid);
@@ -488,7 +491,7 @@ int64_t hcall_set_vm_memmap(struct vm *vm, uint64_t vmid, uint64_t param)
 	return _set_vm_memmap(vm, target_vm, &memmap);
 }
 
-int64_t hcall_set_vm_memmaps(struct vm *vm, uint64_t param)
+int32_t hcall_set_vm_memmaps(struct vm *vm, uint64_t param)
 {
 	struct set_memmaps set_memmaps;
 	struct memory_map *regions;
@@ -531,9 +534,9 @@ int64_t hcall_set_vm_memmaps(struct vm *vm, uint64_t param)
 	return 0;
 }
 
-int64_t hcall_remap_pci_msix(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_remap_pci_msix(struct vm *vm, uint64_t vmid, uint64_t param)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	struct acrn_vm_pci_msix_remap remap;
 	struct ptdev_msi_info info;
 	struct vm *target_vm = get_vm_from_vmid(vmid);
@@ -572,9 +575,9 @@ int64_t hcall_remap_pci_msix(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_gpa_to_hpa(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_gpa_to_hpa(struct vm *vm, uint64_t vmid, uint64_t param)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	struct vm_gpa2hpa v_gpa2hpa;
 	struct vm *target_vm = get_vm_from_vmid(vmid);
 
@@ -597,9 +600,9 @@ int64_t hcall_gpa_to_hpa(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_assign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_assign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param)
 {
-	int64_t ret;
+	int32_t ret;
 	uint16_t bdf;
 	struct vm *target_vm = get_vm_from_vmid(vmid);
 
@@ -635,9 +638,9 @@ int64_t hcall_assign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_deassign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_deassign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	uint16_t bdf;
 	struct vm *target_vm = get_vm_from_vmid(vmid);
 
@@ -655,9 +658,9 @@ int64_t hcall_deassign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_set_ptdev_intr_info(struct vm *vm, uint64_t vmid, uint64_t param)
+int32_t hcall_set_ptdev_intr_info(struct vm *vm, uint64_t vmid, uint64_t param)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	struct hc_ptdev_irq irq;
 	struct vm *target_vm = get_vm_from_vmid(vmid);
 
@@ -689,10 +692,10 @@ int64_t hcall_set_ptdev_intr_info(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t
+int32_t
 hcall_reset_ptdev_intr_info(struct vm *vm, uint64_t vmid, uint64_t param)
 {
-	int64_t ret = 0;
+	int32_t ret = 0;
 	struct hc_ptdev_irq irq;
 	struct vm *target_vm = get_vm_from_vmid(vmid);
 
@@ -723,7 +726,7 @@ hcall_reset_ptdev_intr_info(struct vm *vm, uint64_t vmid, uint64_t param)
 	return ret;
 }
 
-int64_t hcall_setup_sbuf(struct vm *vm, uint64_t param)
+int32_t hcall_setup_sbuf(struct vm *vm, uint64_t param)
 {
 	struct sbuf_setup_param ssp;
 	uint64_t *hva;
@@ -744,7 +747,7 @@ int64_t hcall_setup_sbuf(struct vm *vm, uint64_t param)
 	return sbuf_share_setup(ssp.pcpu_id, ssp.sbuf_id, hva);
 }
 
-int64_t hcall_get_cpu_pm_state(struct vm *vm, uint64_t cmd, uint64_t param)
+int32_t hcall_get_cpu_pm_state(struct vm *vm, uint64_t cmd, uint64_t param)
 {
 	uint16_t target_vm_id;
 	struct vm *target_vm;
diff --git a/hypervisor/common/trusty_hypercall.c b/hypervisor/common/trusty_hypercall.c
index 204a7db29..f6cbdcebd 100644
--- a/hypervisor/common/trusty_hypercall.c
+++ b/hypervisor/common/trusty_hypercall.c
@@ -10,7 +10,7 @@
 /* this hcall is only come from trusty enabled vcpu itself, and cannot be
  * called from other vcpus
  */
-int64_t hcall_world_switch(struct vcpu *vcpu)
+int32_t hcall_world_switch(struct vcpu *vcpu)
 {
 	int32_t next_world_id = !(vcpu->arch_vcpu.cur_context);
 
@@ -37,7 +37,7 @@ int64_t hcall_world_switch(struct vcpu *vcpu)
 /* this hcall is only come from trusty enabled vcpu itself, and cannot be
  * called from other vcpus
  */
-int64_t hcall_initialize_trusty(struct vcpu *vcpu, uint64_t param)
+int32_t hcall_initialize_trusty(struct vcpu *vcpu, uint64_t param)
 {
 	if (!vcpu->vm->sworld_control.sworld_enabled) {
 		pr_err("%s, Secure World is not enabled!\n", __func__);
diff --git a/hypervisor/include/common/hypercall.h b/hypervisor/include/common/hypercall.h
index d08ecc84e..3fe54324a 100644
--- a/hypervisor/include/common/hypercall.h
+++ b/hypervisor/include/common/hypercall.h
@@ -35,7 +35,7 @@ bool is_hypercall_from_ring0(void);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_get_api_version(struct vm *vm, uint64_t param);
+int32_t hcall_get_api_version(struct vm *vm, uint64_t param);
 
 /**
  * @brief create virtual machine
@@ -50,7 +50,7 @@ int64_t hcall_get_api_version(struct vm *vm, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_create_vm(struct vm *vm, uint64_t param);
+int32_t hcall_create_vm(struct vm *vm, uint64_t param);
 
 /**
  * @brief destroy virtual machine
@@ -62,7 +62,7 @@ int64_t hcall_create_vm(struct vm *vm, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_destroy_vm(uint64_t vmid);
+int32_t hcall_destroy_vm(uint64_t vmid);
 
 /**
  * @brief resume virtual machine
@@ -75,7 +75,7 @@ int64_t hcall_destroy_vm(uint64_t vmid);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_resume_vm(uint64_t vmid);
+int32_t hcall_resume_vm(uint64_t vmid);
 
 /**
  * @brief pause virtual machine
@@ -88,7 +88,7 @@ int64_t hcall_resume_vm(uint64_t vmid);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_pause_vm(uint64_t vmid);
+int32_t hcall_pause_vm(uint64_t vmid);
 
 /**
  * @brief create vcpu
@@ -104,7 +104,7 @@ int64_t hcall_pause_vm(uint64_t vmid);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_create_vcpu(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_create_vcpu(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief assert IRQ line
@@ -119,7 +119,7 @@ int64_t hcall_create_vcpu(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_assert_irqline(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_assert_irqline(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief deassert IRQ line
@@ -134,7 +134,7 @@ int64_t hcall_assert_irqline(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_deassert_irqline(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_deassert_irqline(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief trigger a pulse on IRQ line
@@ -149,7 +149,7 @@ int64_t hcall_deassert_irqline(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_pulse_irqline(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_pulse_irqline(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief inject MSI interrupt
@@ -163,7 +163,7 @@ int64_t hcall_pulse_irqline(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_inject_msi(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_inject_msi(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief set ioreq shared buffer
@@ -178,7 +178,7 @@ int64_t hcall_inject_msi(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_set_ioreq_buffer(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_set_ioreq_buffer(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief notify request done
@@ -191,7 +191,7 @@ int64_t hcall_set_ioreq_buffer(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_notify_req_finish(uint64_t vmid, uint64_t param);
+int32_t hcall_notify_req_finish(uint64_t vmid, uint64_t param);
 
 /**
  * @brief setup ept memory mapping
@@ -206,7 +206,7 @@ int64_t hcall_notify_req_finish(uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_set_vm_memmap(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_set_vm_memmap(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief setup ept memory mapping for multi regions
@@ -217,7 +217,7 @@ int64_t hcall_set_vm_memmap(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_set_vm_memmaps(struct vm *vm, uint64_t param);
+int32_t hcall_set_vm_memmaps(struct vm *vm, uint64_t param);
 
 /**
  * @brief remap PCI MSI interrupt
@@ -232,7 +232,7 @@ int64_t hcall_set_vm_memmaps(struct vm *vm, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_remap_pci_msix(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_remap_pci_msix(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief translate guest physical address to host physical address
@@ -246,7 +246,7 @@ int64_t hcall_remap_pci_msix(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_gpa_to_hpa(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_gpa_to_hpa(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief Assign one passthrough dev to VM.
@@ -258,7 +258,7 @@ int64_t hcall_gpa_to_hpa(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_assign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_assign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief Deassign one passthrough dev from VM.
@@ -270,7 +270,7 @@ int64_t hcall_assign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_deassign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_deassign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief Set interrupt mapping info of ptdev.
@@ -282,7 +282,7 @@ int64_t hcall_deassign_ptdev(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_set_ptdev_intr_info(struct vm *vm, uint64_t vmid, uint64_t param);
+int32_t hcall_set_ptdev_intr_info(struct vm *vm, uint64_t vmid, uint64_t param);
 
 /**
  * @brief Clear interrupt mapping info of ptdev.
@@ -294,7 +294,7 @@ int64_t hcall_set_ptdev_intr_info(struct vm *vm, uint64_t vmid, uint64_t param);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_reset_ptdev_intr_info(struct vm *vm, uint64_t vmid,
+int32_t hcall_reset_ptdev_intr_info(struct vm *vm, uint64_t vmid,
 	uint64_t param);
 
 /**
@@ -306,7 +306,7 @@ int64_t hcall_reset_ptdev_intr_info(struct vm *vm, uint64_t vmid,
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_setup_sbuf(struct vm *vm, uint64_t param);
+int32_t hcall_setup_sbuf(struct vm *vm, uint64_t param);
 
 /**
  * @brief Get VCPU Power state.
@@ -318,7 +318,7 @@ int64_t hcall_setup_sbuf(struct vm *vm, uint64_t param);
  * @return 0 on success, non-zero on error.
  */
 
-int64_t hcall_get_cpu_pm_state(struct vm *vm, uint64_t cmd, uint64_t param);
+int32_t hcall_get_cpu_pm_state(struct vm *vm, uint64_t cmd, uint64_t param);
 
 /**
  * @defgroup trusty_hypercall Trusty Hypercalls
@@ -344,7 +344,7 @@ int64_t hcall_get_cpu_pm_state(struct vm *vm, uint64_t cmd, uint64_t param);
  * @return 0 on success, non-zero on error.
  */
 
-int64_t hcall_world_switch(struct vcpu *vcpu);
+int32_t hcall_world_switch(struct vcpu *vcpu);
 
 /**
  * @brief Initialize environment for Trusty-OS on a vCPU.
@@ -360,7 +360,7 @@ int64_t hcall_world_switch(struct vcpu *vcpu);
  *
  * @return 0 on success, non-zero on error.
  */
-int64_t hcall_initialize_trusty(struct vcpu *vcpu, uint64_t param);
+int32_t hcall_initialize_trusty(struct vcpu *vcpu, uint64_t param);
 
 /**
  * @}