diff --git a/hypervisor/arch/x86/assign.c b/hypervisor/arch/x86/assign.c
index 94475decf..1dad43d15 100644
--- a/hypervisor/arch/x86/assign.c
+++ b/hypervisor/arch/x86/assign.c
@@ -537,7 +537,7 @@ void ptirq_intx_ack(struct acrn_vm *vm, uint8_t virt_pin,
  * entry_nr = 0 means first vector
  * user must provide bdf and entry_nr
  */
-int ptirq_msix_remap(struct acrn_vm *vm, uint16_t virt_bdf,
+int32_t ptirq_msix_remap(struct acrn_vm *vm, uint16_t virt_bdf,
 		uint16_t entry_nr, struct ptirq_msi_info *info)
 {
 	struct ptirq_remapping_info *entry;
@@ -625,7 +625,7 @@ static void activate_physical_ioapic(struct acrn_vm *vm,
 /* Main entry for PCI/Legacy device assignment with INTx, calling from vIOAPIC
  * or vPIC
  */
-int ptirq_intx_pin_remap(struct acrn_vm *vm, uint8_t virt_pin,
+int32_t ptirq_intx_pin_remap(struct acrn_vm *vm, uint8_t virt_pin,
 		enum ptirq_vpin_source vpin_src)
 {
 	struct ptirq_remapping_info *entry;
@@ -731,7 +731,7 @@ END:
  * - currently, one phys_pin can only be held by one pin source (vPIC or
  *   vIOAPIC)
  */
-int ptirq_add_intx_remapping(struct acrn_vm *vm, uint8_t virt_pin, uint8_t phys_pin,
+int32_t ptirq_add_intx_remapping(struct acrn_vm *vm, uint8_t virt_pin, uint8_t phys_pin,
 				bool pic_pin)
 {
 	struct ptirq_remapping_info *entry;
@@ -758,7 +758,7 @@ void ptirq_remove_intx_remapping(struct acrn_vm *vm, uint8_t virt_pin, bool pic_
  * - the entry is identified by phys_bdf:msi_idx:
  *   one entry vs. one phys_bdf:msi_idx
  */
-int ptirq_add_msix_remapping(struct acrn_vm *vm, uint16_t virt_bdf,
+int32_t ptirq_add_msix_remapping(struct acrn_vm *vm, uint16_t virt_bdf,
 		uint16_t phys_bdf, uint32_t vector_count)
 {
 	struct ptirq_remapping_info *entry;
diff --git a/hypervisor/arch/x86/cpu.c b/hypervisor/arch/x86/cpu.c
index 2ace517bc..5595bbbe0 100644
--- a/hypervisor/arch/x86/cpu.c
+++ b/hypervisor/arch/x86/cpu.c
@@ -52,7 +52,7 @@ static void cpu_xsave_init(void);
 static void set_current_cpu_id(uint16_t pcpu_id);
 static void print_hv_banner(void);
 static uint16_t get_cpu_id_from_lapic_id(uint32_t lapic_id);
-int ibrs_type;
+int32_t ibrs_type;
 static uint64_t start_tsc __attribute__((__section__(".bss_noinit")));
 
 /* Push sp magic to top of stack for call trace */
@@ -184,9 +184,9 @@ static void get_cpu_capabilities(void)
  * we should supplement which feature/capability we must support
  * here later.
  */
-static int hardware_detect_support(void)
+static int32_t hardware_detect_support(void)
 {
-	int ret;
+	int32_t ret;
 
 	/* Long Mode (x86-64, 64-bit support) */
 	if (!cpu_has_cap(X86_FEATURE_LM)) {
@@ -702,7 +702,7 @@ void cpu_dead(uint16_t pcpu_id)
 	/* For debug purposes, using a stack variable in the while loop enables
 	 * us to modify the value using a JTAG probe and resume if needed.
 	 */
-	int halt = 1;
+	int32_t halt = 1;
 
 	if (bitmap_test_and_clear_lock(pcpu_id, &pcpu_active_bitmap)) {
 		/* clean up native stuff */
diff --git a/hypervisor/arch/x86/cpu_state_tbl.c b/hypervisor/arch/x86/cpu_state_tbl.c
index b3a6582e7..36d74ceb7 100644
--- a/hypervisor/arch/x86/cpu_state_tbl.c
+++ b/hypervisor/arch/x86/cpu_state_tbl.c
@@ -102,10 +102,10 @@ static const struct cpu_state_table {
 	}
 };
 
-static int get_state_tbl_idx(const char *cpuname)
+static int32_t get_state_tbl_idx(const char *cpuname)
 {
-	int i;
-	int count = ARRAY_SIZE(cpu_state_tbl);
+	int32_t i;
+	int32_t count = ARRAY_SIZE(cpu_state_tbl);
 
 	if (cpuname == NULL) {
 		return -1;
@@ -123,7 +123,7 @@ static int get_state_tbl_idx(const char *cpuname)
 
 void load_cpu_state_data(void)
 {
-	int tbl_idx;
+	int32_t tbl_idx;
 	const struct cpu_state_info *state_info;
 
 	(void)memset(&boot_cpu_data.state_info, 0U,
diff --git a/hypervisor/arch/x86/cpuid.c b/hypervisor/arch/x86/cpuid.c
index 1e8188fa9..5a6b0c0dc 100644
--- a/hypervisor/arch/x86/cpuid.c
+++ b/hypervisor/arch/x86/cpuid.c
@@ -176,9 +176,9 @@ static void init_vcpuid_entry(uint32_t leaf, uint32_t subleaf,
 	}
 }
 
-int set_vcpuid_entries(struct acrn_vm *vm)
+int32_t set_vcpuid_entries(struct acrn_vm *vm)
 {
-	int result;
+	int32_t result;
 	struct vcpuid_entry entry;
 	uint32_t limit;
 	uint32_t i, j;
diff --git a/hypervisor/arch/x86/ept.c b/hypervisor/arch/x86/ept.c
index 04a882c9b..5f62c8083 100644
--- a/hypervisor/arch/x86/ept.c
+++ b/hypervisor/arch/x86/ept.c
@@ -71,9 +71,9 @@ uint64_t vm0_hpa2gpa(uint64_t hpa)
 	return hpa;
 }
 
-int ept_violation_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t ept_violation_vmexit_handler(struct acrn_vcpu *vcpu)
 {
-	int status = -EINVAL, ret;
+	int32_t status = -EINVAL, ret;
 	uint64_t exit_qual;
 	uint64_t gpa;
 	struct io_request *io_req = &vcpu->req;
@@ -158,9 +158,9 @@ out:
 	return status;
 }
 
-int ept_misconfig_vmexit_handler(__unused struct acrn_vcpu *vcpu)
+int32_t ept_misconfig_vmexit_handler(__unused struct acrn_vcpu *vcpu)
 {
-	int status;
+	int32_t status;
 
 	status = -EINVAL;
 
diff --git a/hypervisor/arch/x86/guest/guest.c b/hypervisor/arch/x86/guest/guest.c
index fd87821c4..59701f40e 100644
--- a/hypervisor/arch/x86/guest/guest.c
+++ b/hypervisor/arch/x86/guest/guest.c
@@ -68,7 +68,7 @@ enum vm_paging_mode get_vcpu_paging_mode(struct acrn_vcpu *vcpu)
 
 /* TODO: Add code to check for Revserved bits, SMAP and PKE when do translation
  * during page walk */
-static int local_gva2gpa_common(struct acrn_vcpu *vcpu, const struct page_walk_info *pw_info,
+static int32_t local_gva2gpa_common(struct acrn_vcpu *vcpu, const struct page_walk_info *pw_info,
 	uint64_t gva, uint64_t *gpa, uint32_t *err_code)
 {
 	uint32_t i;
@@ -77,8 +77,8 @@ static int local_gva2gpa_common(struct acrn_vcpu *vcpu, const struct page_walk_i
 	void *base;
 	uint64_t entry;
 	uint64_t addr, page_size;
-	int ret = 0;
-	int fault = 0;
+	int32_t ret = 0;
+	int32_t fault = 0;
 	bool is_user_mode_addr = true;
 	bool is_page_rw_flags_on = true;
 
@@ -215,14 +215,14 @@ out:
 	return ret;
 }
 
-static int local_gva2gpa_pae(struct acrn_vcpu *vcpu, struct page_walk_info *pw_info,
+static int32_t local_gva2gpa_pae(struct acrn_vcpu *vcpu, struct page_walk_info *pw_info,
 	uint64_t gva, uint64_t *gpa, uint32_t *err_code)
 {
-	int index;
+	int32_t index;
 	uint64_t *base;
 	uint64_t entry;
 	uint64_t addr;
-	int ret;
+	int32_t ret;
 
 	addr = pw_info->top_entry & 0xFFFFFFF0U;
 	base = (uint64_t *)gpa2hva(vcpu->vm, addr);
@@ -265,12 +265,12 @@ out:
  * - Return -EFAULT for paging fault, and refer to err_code for paging fault
  *   error code.
  */
-int gva2gpa(struct acrn_vcpu *vcpu, uint64_t gva, uint64_t *gpa,
+int32_t gva2gpa(struct acrn_vcpu *vcpu, uint64_t gva, uint64_t *gpa,
 	uint32_t *err_code)
 {
 	enum vm_paging_mode pm = get_vcpu_paging_mode(vcpu);
 	struct page_walk_info pw_info;
-	int ret = 0;
+	int32_t ret = 0;
 
 	if ((gpa == NULL) || (err_code == NULL)) {
 		return -EINVAL;
@@ -356,7 +356,7 @@ static inline uint32_t local_copy_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t
 	return len;
 }
 
-static inline int copy_gpa(struct acrn_vm *vm, void *h_ptr_arg, uint64_t gpa_arg,
+static inline int32_t copy_gpa(struct acrn_vm *vm, void *h_ptr_arg, uint64_t gpa_arg,
 	uint32_t size_arg, bool cp_from_vm)
 {
 	void *h_ptr = h_ptr_arg;
@@ -381,7 +381,7 @@ static inline int copy_gpa(struct acrn_vm *vm, void *h_ptr_arg, uint64_t gpa_arg
 /*
  * @pre vcpu != NULL && err_code != NULL
  */
-static inline int copy_gva(struct acrn_vcpu *vcpu, void *h_ptr_arg, uint64_t gva_arg,
+static inline int32_t copy_gva(struct acrn_vcpu *vcpu, void *h_ptr_arg, uint64_t gva_arg,
 	uint32_t size_arg, uint32_t *err_code, uint64_t *fault_addr,
 	bool cp_from_vm)
 {
@@ -423,7 +423,7 @@ static inline int copy_gva(struct acrn_vcpu *vcpu, void *h_ptr_arg, uint64_t gva
  *   continuous
  * @pre Pointer vm is non-NULL
  */
-int copy_from_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size)
+int32_t copy_from_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size)
 {
 	return copy_gpa(vm, h_ptr, gpa, size, 1);
 }
@@ -434,18 +434,18 @@ int copy_from_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size)
  *   continuous
  * @pre Pointer vm is non-NULL
  */
-int copy_to_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size)
+int32_t copy_to_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size)
 {
 	return copy_gpa(vm, h_ptr, gpa, size, 0);
 }
 
-int copy_from_gva(struct acrn_vcpu *vcpu, void *h_ptr, uint64_t gva,
+int32_t copy_from_gva(struct acrn_vcpu *vcpu, void *h_ptr, uint64_t gva,
 	uint32_t size, uint32_t *err_code, uint64_t *fault_addr)
 {
 	return copy_gva(vcpu, h_ptr, gva, size, err_code, fault_addr, 1);
 }
 
-int copy_to_gva(struct acrn_vcpu *vcpu, void *h_ptr, uint64_t gva,
+int32_t copy_to_gva(struct acrn_vcpu *vcpu, void *h_ptr, uint64_t gva,
 	uint32_t size, uint32_t *err_code, uint64_t *fault_addr)
 {
 	return copy_gva(vcpu, h_ptr, gva, size, err_code, fault_addr, 0);
@@ -459,7 +459,7 @@ int copy_to_gva(struct acrn_vcpu *vcpu, void *h_ptr, uint64_t gva,
  * @pre vm != NULL
  * @pre is_vm0(vm) == true
  */
-int prepare_vm0_memmap(struct acrn_vm *vm)
+int32_t prepare_vm0_memmap(struct acrn_vm *vm)
 {
 	uint32_t i;
 	uint64_t attr_uc = (EPT_RWX | EPT_UNCACHED);
diff --git a/hypervisor/arch/x86/guest/instr_emul.c b/hypervisor/arch/x86/guest/instr_emul.c
index fe442b29a..6f8f74088 100644
--- a/hypervisor/arch/x86/guest/instr_emul.c
+++ b/hypervisor/arch/x86/guest/instr_emul.c
@@ -399,7 +399,7 @@ static void get_guest_paging_info(struct acrn_vcpu *vcpu, struct instr_emul_ctxt
 	emul_ctxt->paging.paging_mode = get_vcpu_paging_mode(vcpu);
 }
 
-static int vie_canonical_check(enum vm_cpu_mode cpu_mode, uint64_t gla)
+static int32_t vie_canonical_check(enum vm_cpu_mode cpu_mode, uint64_t gla)
 {
 	uint64_t mask;
 
@@ -461,7 +461,7 @@ static bool is_desc_valid(struct seg_desc *desc, uint32_t prot)
  *return 0 - on success
  *return -1 - on failure
  */
-static int vie_calculate_gla(enum vm_cpu_mode cpu_mode, enum cpu_reg_name seg,
+static int32_t vie_calculate_gla(enum vm_cpu_mode cpu_mode, enum cpu_reg_name seg,
 	struct seg_desc *desc, uint64_t offset_arg, uint8_t addrsize,
 	uint64_t *gla)
 {
@@ -509,7 +509,7 @@ static inline void vie_mmio_write(struct acrn_vcpu *vcpu, uint64_t wval)
 }
 
 static void vie_calc_bytereg(const struct instr_emul_vie *vie,
-					enum cpu_reg_name *reg, int *lhbr)
+					enum cpu_reg_name *reg, int32_t *lhbr)
 {
 	*lhbr = 0;
 	*reg = (enum cpu_reg_name)(vie->reg);
@@ -536,7 +536,7 @@ static void vie_calc_bytereg(const struct instr_emul_vie *vie,
 
 static uint8_t vie_read_bytereg(const struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
-	int lhbr;
+	int32_t lhbr;
 	uint64_t val;
 	uint8_t reg_val;
 	enum cpu_reg_name reg;
@@ -562,7 +562,7 @@ static void vie_write_bytereg(struct acrn_vcpu *vcpu, const struct instr_emul_vi
 {
 	uint64_t origval, val, mask;
 	enum cpu_reg_name reg;
-	int lhbr;
+	int32_t lhbr;
 
 	vie_calc_bytereg(vie, &reg, &lhbr);
 	origval = vm_get_register(vcpu, reg);
@@ -660,9 +660,9 @@ static uint64_t getcc(uint8_t opsize, uint64_t x, uint64_t y)
 	}
 }
 
-static int emulate_mov(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
+static int32_t emulate_mov(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
-	int error;
+	int32_t error;
 	uint8_t size;
 	enum cpu_reg_name reg;
 	uint8_t byte;
@@ -771,9 +771,9 @@ static int emulate_mov(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 	return error;
 }
 
-static int emulate_movx(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
+static int32_t emulate_movx(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
-	int error;
+	int32_t error;
 	uint8_t size;
 	enum cpu_reg_name reg;
 	uint64_t val;
@@ -890,10 +890,10 @@ static void get_gva_si_nocheck(const struct acrn_vcpu *vcpu, uint8_t addrsize,
  *
  * It's only used by MOVS/STO
  */
-static int get_gva_di_check(struct acrn_vcpu *vcpu, struct instr_emul_vie *vie,
+static int32_t get_gva_di_check(struct acrn_vcpu *vcpu, struct instr_emul_vie *vie,
 		uint8_t addrsize, uint64_t *gva)
 {
-	int ret;
+	int32_t ret;
 	uint32_t err_code;
 	struct seg_desc desc;
 	enum vm_cpu_mode cpu_mode;
@@ -962,14 +962,14 @@ exception_inject:
  * For MOVs instruction, we always check RDI during instruction decoding phase.
  * And access RSI without any check during instruction emulation phase.
  */
-static int emulate_movs(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
+static int32_t emulate_movs(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
 	uint64_t src_gva, gpa, val = 0UL;
 	uint64_t *dst_hva, *src_hva;
 	uint64_t rcx, rdi, rsi, rflags;
 	uint32_t err_code;
 	enum cpu_reg_name seg;
-	int error;
+	int32_t error;
 	uint8_t repeat, opsize = vie->opsize;
 	bool is_mmio_write;
 
@@ -1049,7 +1049,7 @@ done:
 	return error;
 }
 
-static int emulate_stos(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
+static int32_t emulate_stos(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
 	uint8_t repeat, opsize = vie->opsize;
 	uint64_t val;
@@ -1099,9 +1099,9 @@ static int emulate_stos(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie
 	return 0;
 }
 
-static int emulate_test(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
+static int32_t emulate_test(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
-	int error;
+	int32_t error;
 	uint8_t size;
 	enum cpu_reg_name reg;
 	uint64_t result, rflags2, val1, val2;
@@ -1163,9 +1163,9 @@ static int emulate_test(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie
 	return error;
 }
 
-static int emulate_and(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
+static int32_t emulate_and(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
-	int error;
+	int32_t error;
 	uint8_t size;
 	enum cpu_reg_name reg;
 	uint64_t result, rflags2, val1, val2;
@@ -1246,9 +1246,9 @@ static int emulate_and(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 	return error;
 }
 
-static int emulate_or(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
+static int32_t emulate_or(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
-	int error;
+	int32_t error;
 	uint8_t size;
 	enum cpu_reg_name reg;
 	uint64_t val1, val2, result, rflags2;
@@ -1332,9 +1332,9 @@ static int emulate_or(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 	return error;
 }
 
-static int emulate_cmp(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
+static int32_t emulate_cmp(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
-	int error = 0;
+	int32_t error = 0;
 	uint8_t size;
 	uint64_t regop, memop, op1, op2, rflags2;
 	enum cpu_reg_name reg;
@@ -1418,9 +1418,9 @@ static int emulate_cmp(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 	return error;
 }
 
-static int emulate_sub(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
+static int32_t emulate_sub(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
-	int error;
+	int32_t error;
 	uint8_t size;
 	uint64_t nval, rflags2, val1, val2;
 	enum cpu_reg_name reg;
@@ -1468,9 +1468,9 @@ static int emulate_sub(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 	return error;
 }
 
-static int emulate_group1(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
+static int32_t emulate_group1(struct acrn_vcpu *vcpu, const struct instr_emul_vie *vie)
 {
-	int error;
+	int32_t error;
 
 	switch (vie->reg & 7U) {
 	case 0x1U:	/* OR */
@@ -1531,11 +1531,11 @@ static int32_t emulate_bittest(struct acrn_vcpu *vcpu, const struct instr_emul_v
 	return ret;
 }
 
-static int vmm_emulate_instruction(struct instr_emul_ctxt *ctxt)
+static int32_t vmm_emulate_instruction(struct instr_emul_ctxt *ctxt)
 {
 	struct instr_emul_vie *vie = &ctxt->vie;
 	struct acrn_vcpu *vcpu = ctxt->vcpu;
-	int error;
+	int32_t error;
 
 	if (vie->decoded != 0U) {
 		switch (vie->op.op_type) {
@@ -1584,13 +1584,13 @@ static int vmm_emulate_instruction(struct instr_emul_ctxt *ctxt)
 	return error;
 }
 
-static int vie_init(struct instr_emul_vie *vie, struct acrn_vcpu *vcpu)
+static int32_t vie_init(struct instr_emul_vie *vie, struct acrn_vcpu *vcpu)
 {
 	uint64_t guest_rip_gva = vcpu_get_rip(vcpu);
 	uint32_t inst_len = vcpu->arch.inst_len;
 	uint32_t err_code;
 	uint64_t fault_addr;
-	int ret;
+	int32_t ret;
 
 	if ((inst_len > VIE_INST_SIZE) || (inst_len == 0U)) {
 		pr_err("%s: invalid instruction length (%d)",
@@ -1620,7 +1620,7 @@ static int vie_init(struct instr_emul_vie *vie, struct acrn_vcpu *vcpu)
 	return 0;
 }
 
-static int vie_peek(const struct instr_emul_vie *vie, uint8_t *x)
+static int32_t vie_peek(const struct instr_emul_vie *vie, uint8_t *x)
 {
 
 	if (vie->num_processed < vie->num_valid) {
@@ -1665,7 +1665,7 @@ static bool segment_override(uint8_t x, enum cpu_reg_name *seg)
 	return true;
 }
 
-static int decode_prefixes(struct instr_emul_vie *vie,
+static int32_t decode_prefixes(struct instr_emul_vie *vie,
 					enum vm_cpu_mode cpu_mode, bool cs_d)
 {
 	uint8_t x, i;
@@ -1737,7 +1737,7 @@ static int decode_prefixes(struct instr_emul_vie *vie,
 	return 0;
 }
 
-static int decode_two_byte_opcode(struct instr_emul_vie *vie)
+static int32_t decode_two_byte_opcode(struct instr_emul_vie *vie)
 {
 	uint8_t x;
 
@@ -1757,9 +1757,9 @@ static int decode_two_byte_opcode(struct instr_emul_vie *vie)
 	return 0;
 }
 
-static int decode_opcode(struct instr_emul_vie *vie)
+static int32_t decode_opcode(struct instr_emul_vie *vie)
 {
-	int ret = 0;
+	int32_t ret = 0;
 	uint8_t x;
 
 	if (vie_peek(vie, &x) != 0) {
@@ -1792,7 +1792,7 @@ static int decode_opcode(struct instr_emul_vie *vie)
 	return ret;
 }
 
-static int decode_modrm(struct instr_emul_vie *vie, enum vm_cpu_mode cpu_mode)
+static int32_t decode_modrm(struct instr_emul_vie *vie, enum vm_cpu_mode cpu_mode)
 {
 	uint8_t x;
 
@@ -1885,7 +1885,7 @@ done:
 	return 0;
 }
 
-static int decode_sib(struct instr_emul_vie *vie)
+static int32_t decode_sib(struct instr_emul_vie *vie)
 {
 	uint8_t x;
 
@@ -1965,7 +1965,7 @@ static int decode_sib(struct instr_emul_vie *vie)
 	return 0;
 }
 
-static int decode_displacement(struct instr_emul_vie *vie)
+static int32_t decode_displacement(struct instr_emul_vie *vie)
 {
 	uint8_t n, i, x;
 
@@ -2004,7 +2004,7 @@ static int decode_displacement(struct instr_emul_vie *vie)
 	return 0;
 }
 
-static int decode_immediate(struct instr_emul_vie *vie)
+static int32_t decode_immediate(struct instr_emul_vie *vie)
 {
 	uint8_t i, n, x;
 	union {
@@ -2067,7 +2067,7 @@ static int decode_immediate(struct instr_emul_vie *vie)
 	return 0;
 }
 
-static int decode_moffset(struct instr_emul_vie *vie)
+static int32_t decode_moffset(struct instr_emul_vie *vie)
 {
 	uint8_t i, n, x;
 	union {
@@ -2102,7 +2102,7 @@ static int decode_moffset(struct instr_emul_vie *vie)
 	return 0;
 }
 
-static int local_decode_instruction(enum vm_cpu_mode cpu_mode,
+static int32_t local_decode_instruction(enum vm_cpu_mode cpu_mode,
 				bool cs_d, struct instr_emul_vie *vie)
 {
 	if (decode_prefixes(vie, cpu_mode, cs_d) != 0) {
@@ -2156,10 +2156,10 @@ static int32_t instr_check_di(struct acrn_vcpu *vcpu, struct instr_emul_ctxt *em
 	return ret;
 }
 
-static int instr_check_gva(struct acrn_vcpu *vcpu, struct instr_emul_ctxt *emul_ctxt,
+static int32_t instr_check_gva(struct acrn_vcpu *vcpu, struct instr_emul_ctxt *emul_ctxt,
 		enum vm_cpu_mode cpu_mode)
 {
-	int ret;
+	int32_t ret;
 	uint64_t base, segbase, idx, gva, gpa;
 	uint32_t err_code;
 	enum cpu_reg_name seg;
@@ -2242,11 +2242,11 @@ static int instr_check_gva(struct acrn_vcpu *vcpu, struct instr_emul_ctxt *emul_
 	return 0;
 }
 
-int decode_instruction(struct acrn_vcpu *vcpu)
+int32_t decode_instruction(struct acrn_vcpu *vcpu)
 {
 	struct instr_emul_ctxt *emul_ctxt;
 	uint32_t csar;
-	int retval;
+	int32_t retval;
 	enum vm_cpu_mode cpu_mode;
 
 	emul_ctxt = &per_cpu(g_inst_ctxt, vcpu->pcpu_id);
@@ -2302,7 +2302,7 @@ int decode_instruction(struct acrn_vcpu *vcpu)
 		}
 	}
 
-	return (int)(emul_ctxt->vie.opsize);
+	return (int32_t)(emul_ctxt->vie.opsize);
 }
 
 int32_t emulate_instruction(const struct acrn_vcpu *vcpu)
diff --git a/hypervisor/arch/x86/guest/instr_emul.h b/hypervisor/arch/x86/guest/instr_emul.h
index 21e5b7596..481dca260 100644
--- a/hypervisor/arch/x86/guest/instr_emul.h
+++ b/hypervisor/arch/x86/guest/instr_emul.h
@@ -195,6 +195,6 @@ struct instr_emul_ctxt {
 };
 
 int32_t emulate_instruction(const struct acrn_vcpu *vcpu);
-int decode_instruction(struct acrn_vcpu *vcpu);
+int32_t decode_instruction(struct acrn_vcpu *vcpu);
 
 #endif
diff --git a/hypervisor/arch/x86/guest/pm.c b/hypervisor/arch/x86/guest/pm.c
index f21ab23d5..a98f8f2e2 100644
--- a/hypervisor/arch/x86/guest/pm.c
+++ b/hypervisor/arch/x86/guest/pm.c
@@ -6,7 +6,7 @@
 
 #include <hypervisor.h>
 
-int validate_pstate(const struct acrn_vm *vm, uint64_t perf_ctl)
+int32_t validate_pstate(const struct acrn_vm *vm, uint64_t perf_ctl)
 {
 	const struct cpu_px_data *px_data;
 	uint8_t i, px_cnt;
@@ -103,7 +103,7 @@ void vm_setup_cpu_state(struct acrn_vm *vm)
 /* This function is for power management Sx state implementation,
  * VM need to load the Sx state data to implement S3/S5.
  */
-int vm_load_pm_s_state(struct acrn_vm *vm)
+int32_t vm_load_pm_s_state(struct acrn_vm *vm)
 {
 #ifdef ACPI_INFO_VALIDATED
 	vm->pm.sx_state_data = (struct pm_s_state_data *)&host_pm_s_state;
diff --git a/hypervisor/arch/x86/guest/ucode.c b/hypervisor/arch/x86/guest/ucode.c
index b8c7c77a8..332eee7cc 100644
--- a/hypervisor/arch/x86/guest/ucode.c
+++ b/hypervisor/arch/x86/guest/ucode.c
@@ -37,7 +37,7 @@ void acrn_update_ucode(struct acrn_vcpu *vcpu, uint64_t v)
 	uint64_t gva, fault_addr;
 	struct ucode_header uhdr;
 	size_t data_size;
-	int err;
+	int32_t err;
 	uint32_t err_code;
 
 	spinlock_obtain(&micro_code_lock);
diff --git a/hypervisor/arch/x86/guest/vcpu.c b/hypervisor/arch/x86/guest/vcpu.c
index b9dd5e402..f2d442ef6 100644
--- a/hypervisor/arch/x86/guest/vcpu.c
+++ b/hypervisor/arch/x86/guest/vcpu.c
@@ -322,7 +322,7 @@ void set_ap_entry(struct acrn_vcpu *vcpu, uint64_t entry)
  *     for physical CPU 1 : vcpu->pcpu_id = 1, vcpu->vcpu_id = 1, vmid = 1;
  *
  ***********************************************************************/
-int create_vcpu(uint16_t pcpu_id, struct acrn_vm *vm, struct acrn_vcpu **rtn_vcpu_handle)
+int32_t create_vcpu(uint16_t pcpu_id, struct acrn_vm *vm, struct acrn_vcpu **rtn_vcpu_handle)
 {
 	struct acrn_vcpu *vcpu;
 	uint16_t vcpu_id;
@@ -399,7 +399,7 @@ int create_vcpu(uint16_t pcpu_id, struct acrn_vm *vm, struct acrn_vcpu **rtn_vcp
 /*
  *  @pre vcpu != NULL
  */
-int run_vcpu(struct acrn_vcpu *vcpu)
+int32_t run_vcpu(struct acrn_vcpu *vcpu)
 {
 	uint32_t instlen, cs_attr;
 	uint64_t rip, ia32_efer, cr0;
@@ -499,7 +499,7 @@ int run_vcpu(struct acrn_vcpu *vcpu)
 	return status;
 }
 
-int shutdown_vcpu(__unused struct acrn_vcpu *vcpu)
+int32_t shutdown_vcpu(__unused struct acrn_vcpu *vcpu)
 {
 	/* TODO : Implement VCPU shutdown sequence */
 
@@ -522,7 +522,7 @@ void offline_vcpu(struct acrn_vcpu *vcpu)
  */
 void reset_vcpu(struct acrn_vcpu *vcpu)
 {
-	int i;
+	int32_t i;
 	struct acrn_vlapic *vlapic;
 
 	pr_dbg("vcpu%hu reset", vcpu->vcpu_id);
@@ -610,9 +610,9 @@ void schedule_vcpu(struct acrn_vcpu *vcpu)
 }
 
 /* help function for vcpu create */
-int prepare_vcpu(struct acrn_vm *vm, uint16_t pcpu_id)
+int32_t prepare_vcpu(struct acrn_vm *vm, uint16_t pcpu_id)
 {
-	int ret = 0;
+	int32_t ret = 0;
 	struct acrn_vcpu *vcpu = NULL;
 
 	ret = create_vcpu(pcpu_id, vm, &vcpu);
diff --git a/hypervisor/arch/x86/guest/vlapic.c b/hypervisor/arch/x86/guest/vlapic.c
index 614c22abe..8b9ce666d 100644
--- a/hypervisor/arch/x86/guest/vlapic.c
+++ b/hypervisor/arch/x86/guest/vlapic.c
@@ -81,10 +81,10 @@ static inline void vlapic_dump_isr(__unused const struct acrn_vlapic *vlapic, __
 /*APIC-v APIC-access address */
 static uint8_t apicv_apic_access_addr[PAGE_SIZE] __aligned(PAGE_SIZE);
 
-static int
+static int32_t
 apicv_set_intr_ready(struct acrn_vlapic *vlapic, uint32_t vector);
 
-static int
+static int32_t
 apicv_pending_intr(const struct acrn_vlapic *vlapic);
 
 static void
@@ -456,14 +456,14 @@ vlapic_esr_write_handler(struct acrn_vlapic *vlapic)
  * Returns 1 if the vcpu needs to be notified of the interrupt and 0 otherwise.
  * @pre vector >= 16
  */
-static int
+static int32_t
 vlapic_set_intr_ready(struct acrn_vlapic *vlapic, uint32_t vector, bool level)
 {
 	struct lapic_regs *lapic;
 	struct lapic_reg *irrptr, *tmrptr;
 	uint32_t mask;
 	uint32_t idx;
-	int pending_intr;
+	int32_t pending_intr;
 
 	ASSERT(vector <= NR_MAX_VECTOR,
 		"invalid vector %u", vector);
@@ -926,7 +926,7 @@ vlapic_set_error(struct acrn_vlapic *vlapic, uint32_t mask)
 /*
  * @pre vector <= 255
  */
-static int
+static int32_t
 vlapic_trigger_lvt(struct acrn_vlapic *vlapic, uint32_t vector)
 {
 	uint32_t lvt;
@@ -1206,7 +1206,7 @@ vlapic_process_init_sipi(struct acrn_vcpu* target_vcpu, uint32_t mode,
 	}
 }
 
-static int
+static int32_t
 vlapic_icrlo_write_handler(struct acrn_vlapic *vlapic)
 {
 	uint16_t vcpu_id;
@@ -1312,7 +1312,7 @@ vlapic_icrlo_write_handler(struct acrn_vlapic *vlapic)
  * @remark The vector does not automatically transition to the ISR as a
  *	   result of calling this function.
  */
-int
+int32_t
 vlapic_pending_intr(const struct acrn_vlapic *vlapic, uint32_t *vecptr)
 {
 	const struct lapic_regs *lapic = &(vlapic->apic_page);
@@ -1442,7 +1442,7 @@ vlapic_svr_write_handler(struct acrn_vlapic *vlapic)
 	}
 }
 
-static int
+static int32_t
 vlapic_read(struct acrn_vlapic *vlapic, uint32_t offset_arg,
 		uint64_t *data)
 {
@@ -1566,14 +1566,14 @@ done:
 	return 0;
 }
 
-static int
+static int32_t
 vlapic_write(struct acrn_vlapic *vlapic, uint32_t offset,
 		uint64_t data)
 {
 	struct lapic_regs *lapic = &(vlapic->apic_page);
 	uint32_t *regptr;
 	uint32_t data32 = (uint32_t)data;
-	int retval;
+	int32_t retval;
 
 	ASSERT(((offset & 0xfU) == 0U) && (offset < PAGE_SIZE),
 		"%s: invalid offset %#x", __func__, offset);
@@ -1728,7 +1728,7 @@ vlapic_init(struct acrn_vlapic *vlapic)
 void vlapic_restore(struct acrn_vlapic *vlapic, const struct lapic_regs *regs)
 {
 	struct lapic_regs *lapic;
-	int i;
+	int32_t i;
 
 	lapic = &(vlapic->apic_page);
 
@@ -1758,7 +1758,7 @@ vlapic_get_apicbase(const struct acrn_vlapic *vlapic)
 	return vlapic->msr_apicbase;
 }
 
-static int
+static int32_t
 vlapic_set_apicbase(struct acrn_vlapic *vlapic, uint64_t new)
 {
 
@@ -1955,7 +1955,7 @@ vlapic_set_local_intr(struct acrn_vm *vm, uint16_t vcpu_id_arg, uint32_t vector)
 {
 	struct acrn_vlapic *vlapic;
 	uint64_t dmask = 0UL;
-	int error;
+	int32_t error;
 	uint16_t vcpu_id = vcpu_id_arg;
 
 	if ((vcpu_id != BROADCAST_CPU_ID) && (vcpu_id >= vm->hw.created_vcpus)) {
@@ -2082,7 +2082,7 @@ static inline  uint32_t x2apic_msr_to_regoff(uint32_t msr)
  * No shorthand and Physical destination mode are only supported.
  */
 
-static int
+static int32_t
 vlapic_x2apic_pt_icr_access(struct acrn_vm *vm, uint64_t val)
 {
 	uint64_t apic_id = (uint32_t) (val >> 32U);
@@ -2123,12 +2123,12 @@ vlapic_x2apic_pt_icr_access(struct acrn_vm *vm, uint64_t val)
 }
 #endif
 
-static int vlapic_x2apic_access(struct acrn_vcpu *vcpu, uint32_t msr, bool write,
+static int32_t vlapic_x2apic_access(struct acrn_vcpu *vcpu, uint32_t msr, bool write,
 								uint64_t *val)
 {
 	struct acrn_vlapic *vlapic;
 	uint32_t offset;
-	int error = -1;
+	int32_t error = -1;
 
 	/*
 	 * If vLAPIC is in xAPIC mode and guest tries to access x2APIC MSRs
@@ -2159,10 +2159,10 @@ static int vlapic_x2apic_access(struct acrn_vcpu *vcpu, uint32_t msr, bool write
 	return error;
 }
 
-int
+int32_t
 vlapic_rdmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t *rval)
 {
-	int error = 0;
+	int32_t error = 0;
 	struct acrn_vlapic *vlapic;
 
 	dev_dbg(ACRN_DBG_LAPIC, "cpu[%hu] rdmsr: %x", vcpu->vcpu_id, msr);
@@ -2191,10 +2191,10 @@ vlapic_rdmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t *rval)
 	return error;
 }
 
-int
+int32_t
 vlapic_wrmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t wval)
 {
-	int error = 0;
+	int32_t error = 0;
 	struct acrn_vlapic *vlapic;
 
 	vlapic = vcpu_vlapic(vcpu);
@@ -2224,7 +2224,7 @@ vlapic_wrmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t wval)
 	return error;
 }
 
-int vlapic_create(struct acrn_vcpu *vcpu)
+int32_t vlapic_create(struct acrn_vcpu *vcpu)
 {
 	vcpu->arch.vlapic.vm = vcpu->vm;
 	vcpu->arch.vlapic.vcpu = vcpu;
@@ -2264,7 +2264,7 @@ void vlapic_free(struct acrn_vcpu *vcpu)
 /**
  * APIC-v functions
  * **/
-static int
+static int32_t
 apicv_set_intr_ready(struct acrn_vlapic *vlapic, uint32_t vector)
 {
 	struct vlapic_pir_desc *pir_desc;
@@ -2282,7 +2282,7 @@ apicv_set_intr_ready(struct acrn_vlapic *vlapic, uint32_t vector)
 	return notify;
 }
 
-static int
+static int32_t
 apicv_pending_intr(const struct acrn_vlapic *vlapic)
 {
 	const struct vlapic_pir_desc *pir_desc;
@@ -2428,9 +2428,9 @@ vlapic_apicv_inject_pir(struct acrn_vlapic *vlapic)
 	}
 }
 
-int apic_access_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t apic_access_vmexit_handler(struct acrn_vcpu *vcpu)
 {
-	int err = 0;
+	int32_t err = 0;
 	uint32_t offset = 0U;
 	uint64_t qual, access_type;
 	struct acrn_vlapic *vlapic;
@@ -2473,7 +2473,7 @@ int apic_access_vmexit_handler(struct acrn_vcpu *vcpu)
 	return err;
 }
 
-int veoi_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t veoi_vmexit_handler(struct acrn_vcpu *vcpu)
 {
 	struct acrn_vlapic *vlapic = NULL;
 
@@ -2514,10 +2514,10 @@ static void vlapic_x2apic_self_ipi_handler(struct acrn_vlapic *vlapic)
 	vlapic_set_intr(target_vcpu, vector, LAPIC_TRIG_EDGE);
 }
 
-int apic_write_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t apic_write_vmexit_handler(struct acrn_vcpu *vcpu)
 {
 	uint64_t qual;
-	int error, handled;
+	int32_t error, handled;
 	uint32_t offset;
 	struct acrn_vlapic *vlapic = NULL;
 
@@ -2584,7 +2584,7 @@ int apic_write_vmexit_handler(struct acrn_vcpu *vcpu)
 	return handled;
 }
 
-int tpr_below_threshold_vmexit_handler(__unused struct acrn_vcpu *vcpu)
+int32_t tpr_below_threshold_vmexit_handler(__unused struct acrn_vcpu *vcpu)
 {
 	pr_err("Unhandled %s.", __func__);
 	return 0;
diff --git a/hypervisor/arch/x86/guest/vm.c b/hypervisor/arch/x86/guest/vm.c
index 6dfb009af..3f0ebb376 100644
--- a/hypervisor/arch/x86/guest/vm.c
+++ b/hypervisor/arch/x86/guest/vm.c
@@ -60,10 +60,10 @@ struct acrn_vm *get_vm_from_vmid(uint16_t vm_id)
 /**
  * @pre vm_desc != NULL && rtn_vm != NULL
  */
-int create_vm(struct vm_description *vm_desc, struct acrn_vm **rtn_vm)
+int32_t create_vm(struct vm_description *vm_desc, struct acrn_vm **rtn_vm)
 {
 	struct acrn_vm *vm;
-	int status;
+	int32_t status;
 	uint16_t vm_id;
 
 #ifdef CONFIG_PARTITION_MODE
@@ -240,7 +240,7 @@ int32_t shutdown_vm(struct acrn_vm *vm)
 /**
  *  * @pre vm != NULL
  */
-int start_vm(struct acrn_vm *vm)
+int32_t start_vm(struct acrn_vm *vm)
 {
 	struct acrn_vcpu *vcpu = NULL;
 
@@ -348,9 +348,9 @@ void resume_vm_from_s3(struct acrn_vm *vm, uint32_t wakeup_vec)
 
 #ifdef CONFIG_PARTITION_MODE
 /* Create vm/vcpu for vm */
-int prepare_vm(uint16_t pcpu_id)
+int32_t prepare_vm(uint16_t pcpu_id)
 {
-	int ret = 0;
+	int32_t ret = 0;
 	uint16_t i;
 	struct acrn_vm *vm = NULL;
 	struct vm_description *vm_desc = NULL;
@@ -389,9 +389,9 @@ int prepare_vm(uint16_t pcpu_id)
 #else
 
 /* Create vm/vcpu for vm0 */
-static int prepare_vm0(void)
+static int32_t prepare_vm0(void)
 {
-	int err;
+	int32_t err;
 	uint16_t i;
 	struct acrn_vm *vm = NULL;
 	struct vm_description vm0_desc;
@@ -428,9 +428,9 @@ static int prepare_vm0(void)
 	return err;
 }
 
-int prepare_vm(uint16_t pcpu_id)
+int32_t prepare_vm(uint16_t pcpu_id)
 {
-	int err = 0;
+	int32_t err = 0;
 
 	/* prepare vm0 if pcpu_id is BOOT_CPU_ID */
 	if (pcpu_id == BOOT_CPU_ID) {
diff --git a/hypervisor/arch/x86/guest/vmcall.c b/hypervisor/arch/x86/guest/vmcall.c
index 300c4f5d7..4903a7803 100644
--- a/hypervisor/arch/x86/guest/vmcall.c
+++ b/hypervisor/arch/x86/guest/vmcall.c
@@ -16,7 +16,7 @@ static spinlock_t vmm_hypercall_lock = {
  * This function should always return 0 since we shouldn't
  * deal with hypercall error in hypervisor.
  */
-int vmcall_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t vmcall_vmexit_handler(struct acrn_vcpu *vcpu)
 {
 	int32_t ret = -EACCES;
 	struct acrn_vm *vm = vcpu->vm;
diff --git a/hypervisor/arch/x86/guest/vmsr.c b/hypervisor/arch/x86/guest/vmsr.c
index 50191b6ff..4c836e6c2 100644
--- a/hypervisor/arch/x86/guest/vmsr.c
+++ b/hypervisor/arch/x86/guest/vmsr.c
@@ -318,9 +318,9 @@ void init_msr_emulation(struct acrn_vcpu *vcpu)
 	init_msr_area(vcpu);
 }
 
-int rdmsr_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t rdmsr_vmexit_handler(struct acrn_vcpu *vcpu)
 {
-	int err = 0;
+	int32_t err = 0;
 	uint32_t msr;
 	uint64_t v = 0UL;
 
@@ -405,9 +405,9 @@ int rdmsr_vmexit_handler(struct acrn_vcpu *vcpu)
 	return err;
 }
 
-int wrmsr_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t wrmsr_vmexit_handler(struct acrn_vcpu *vcpu)
 {
-	int err = 0;
+	int32_t err = 0;
 	uint32_t msr;
 	uint64_t v;
 
diff --git a/hypervisor/arch/x86/io.c b/hypervisor/arch/x86/io.c
index 75075dc13..012d5860b 100644
--- a/hypervisor/arch/x86/io.c
+++ b/hypervisor/arch/x86/io.c
@@ -241,7 +241,7 @@ hv_emulate_pio(const struct acrn_vcpu *vcpu, struct io_request *io_req)
 static int32_t
 hv_emulate_mmio(struct acrn_vcpu *vcpu, struct io_request *io_req)
 {
-	int status = -ENODEV;
+	int32_t status = -ENODEV;
 	uint16_t idx;
 	uint64_t address, size;
 	struct mmio_request *mmio_req = &io_req->reqs.mmio;
@@ -475,11 +475,11 @@ void register_io_emulation_handler(struct acrn_vm *vm, uint32_t pio_idx,
  * @retval 0 Registration succeeds
  * @retval -EINVAL \p read_write is NULL, \p end is not larger than \p start or \p vm has been launched
  */
-int register_mmio_emulation_handler(struct acrn_vm *vm,
+int32_t register_mmio_emulation_handler(struct acrn_vm *vm,
 	hv_mem_io_handler_t read_write, uint64_t start,
 	uint64_t end, void *handler_private_data)
 {
-	int status = -EINVAL;
+	int32_t status = -EINVAL;
 	struct mem_io_node *mmio_node;
 
 	if ((vm->hw.created_vcpus > 0U) && vm->hw.vcpu_array[0].launched) {
diff --git a/hypervisor/arch/x86/mmu.c b/hypervisor/arch/x86/mmu.c
index 56935ce40..bd170b4f7 100644
--- a/hypervisor/arch/x86/mmu.c
+++ b/hypervisor/arch/x86/mmu.c
@@ -66,7 +66,7 @@ struct invept_desc {
 
 static inline void local_invvpid(uint64_t type, uint16_t vpid, uint64_t gva)
 {
-	int error = 0;
+	int32_t error = 0;
 
 	struct {
 		uint32_t vpid : 16;
@@ -86,7 +86,7 @@ static inline void local_invvpid(uint64_t type, uint16_t vpid, uint64_t gva)
 
 static inline void local_invept(uint64_t type, struct invept_desc desc)
 {
-	int error = 0;
+	int32_t error = 0;
 
 	asm volatile ("invept %1, %2\n"
 			VMFAIL_INVALID_EPT_VPID
@@ -107,7 +107,7 @@ static inline bool cpu_has_vmx_vpid_cap(uint32_t bit_mask)
 	return ((vmx_caps.vpid & bit_mask) != 0U);
 }
 
-int check_vmx_mmu_cap(void)
+int32_t check_vmx_mmu_cap(void)
 {
 	uint64_t val;
 
diff --git a/hypervisor/arch/x86/notify.c b/hypervisor/arch/x86/notify.c
index 2048e3528..7e3ef679d 100644
--- a/hypervisor/arch/x86/notify.c
+++ b/hypervisor/arch/x86/notify.c
@@ -55,7 +55,7 @@ void smp_call_function(uint64_t mask, smp_call_func_t func, void *data)
 	wait_sync_change(&smp_call_mask, 0UL);
 }
 
-static int request_notification_irq(irq_action_t func, void *data)
+static int32_t request_notification_irq(irq_action_t func, void *data)
 {
 	int32_t retval;
 
diff --git a/hypervisor/arch/x86/static_checks.c b/hypervisor/arch/x86/static_checks.c
index dd4584bf3..f0564763c 100644
--- a/hypervisor/arch/x86/static_checks.c
+++ b/hypervisor/arch/x86/static_checks.c
@@ -9,7 +9,7 @@
 #define CAT__(A,B) A ## B
 #define CAT_(A,B) CAT__(A,B)
 #define CTASSERT(expr) \
-typedef int CAT_(CTA_DummyType,__LINE__)[(expr) ? 1 : -1]
+typedef int32_t CAT_(CTA_DummyType,__LINE__)[(expr) ? 1 : -1]
 
 /* Build time sanity checks to make sure hard-coded offset
 *  is matching the actual offset!
diff --git a/hypervisor/arch/x86/timer.c b/hypervisor/arch/x86/timer.c
index 238e35493..ae4d34e62 100644
--- a/hypervisor/arch/x86/timer.c
+++ b/hypervisor/arch/x86/timer.c
@@ -70,7 +70,7 @@ static void local_add_timer(struct per_cpu_timers *cpu_timer,
 	}
 }
 
-int add_timer(struct hv_timer *timer)
+int32_t add_timer(struct hv_timer *timer)
 {
 	struct per_cpu_timers *cpu_timer;
 	uint16_t pcpu_id;
@@ -134,7 +134,7 @@ static void timer_softirq(uint16_t pcpu_id)
 	struct per_cpu_timers *cpu_timer;
 	struct hv_timer *timer;
 	struct list_head *pos, *n;
-	int tries = MAX_TIMER_ACTIONS;
+	int32_t tries = MAX_TIMER_ACTIONS;
 	uint64_t current_tsc = rdtsc();
 
 	/* handle passed timer */
diff --git a/hypervisor/arch/x86/trampoline.c b/hypervisor/arch/x86/trampoline.c
index 010ea22cf..fb0330258 100644
--- a/hypervisor/arch/x86/trampoline.c
+++ b/hypervisor/arch/x86/trampoline.c
@@ -43,7 +43,7 @@ static void update_trampoline_code_refs(uint64_t dest_pa)
 {
 	void *ptr;
 	uint64_t val;
-	int i;
+	int32_t i;
 
 	/*
 	 * calculate the fixup CS:IP according to fixup target address
diff --git a/hypervisor/arch/x86/trusty.c b/hypervisor/arch/x86/trusty.c
index 7385a1c0b..70a0d89cf 100644
--- a/hypervisor/arch/x86/trusty.c
+++ b/hypervisor/arch/x86/trusty.c
@@ -279,7 +279,7 @@ static void copy_smc_param(const struct run_context *prev_ctx,
 	next_ctx->guest_cpu_regs.regs.rbx = prev_ctx->guest_cpu_regs.regs.rbx;
 }
 
-void switch_world(struct acrn_vcpu *vcpu, int next_world)
+void switch_world(struct acrn_vcpu *vcpu, int32_t next_world)
 {
 	struct acrn_vcpu_arch *arch = &vcpu->arch;
 
diff --git a/hypervisor/arch/x86/virq.c b/hypervisor/arch/x86/virq.c
index cebc8ea8e..e669150e4 100644
--- a/hypervisor/arch/x86/virq.c
+++ b/hypervisor/arch/x86/virq.c
@@ -74,7 +74,7 @@ static bool vcpu_pending_request(struct acrn_vcpu *vcpu)
 {
 	struct acrn_vlapic *vlapic;
 	uint32_t vector = 0U;
-	int ret = 0;
+	int32_t ret = 0;
 
 	/* Query vLapic to get vector to inject */
 	vlapic = vcpu_vlapic(vcpu);
@@ -108,11 +108,11 @@ void vcpu_make_request(struct acrn_vcpu *vcpu, uint16_t eventid)
 	}
 }
 
-static int vcpu_inject_vlapic_int(struct acrn_vcpu *vcpu)
+static int32_t vcpu_inject_vlapic_int(struct acrn_vcpu *vcpu)
 {
 	struct acrn_vlapic *vlapic = vcpu_vlapic(vcpu);
 	uint32_t vector = 0U;
-	int ret = 0;
+	int32_t ret = 0;
 
 	/*
 	 * This function used for inject virtual interrupt
@@ -148,7 +148,7 @@ static int vcpu_inject_vlapic_int(struct acrn_vcpu *vcpu)
 	return 0;
 }
 
-static int vcpu_do_pending_extint(const struct acrn_vcpu *vcpu)
+static int32_t vcpu_do_pending_extint(const struct acrn_vcpu *vcpu)
 {
 	struct acrn_vm *vm;
 	struct acrn_vcpu *primary;
@@ -176,7 +176,7 @@ static int vcpu_do_pending_extint(const struct acrn_vcpu *vcpu)
 }
 
 /* SDM Vol3 -6.15, Table 6-4 - interrupt and exception classes */
-static int get_excep_class(uint32_t vector)
+static int32_t get_excep_class(uint32_t vector)
 {
 	if ((vector == IDT_DE) || (vector == IDT_TS) || (vector == IDT_NP) ||
 		(vector == IDT_SS) || (vector == IDT_GP)) {
@@ -188,7 +188,7 @@ static int get_excep_class(uint32_t vector)
 	}
 }
 
-int vcpu_queue_exception(struct acrn_vcpu *vcpu, uint32_t vector, uint32_t err_code)
+int32_t vcpu_queue_exception(struct acrn_vcpu *vcpu, uint32_t vector, uint32_t err_code)
 {
 	struct acrn_vcpu_arch *arch = &vcpu->arch;
 	/* VECTOR_INVALID is also greater than 32 */
@@ -328,7 +328,7 @@ void vcpu_inject_ss(struct acrn_vcpu *vcpu)
 	vcpu_make_request(vcpu, ACRN_REQUEST_EXCP);
 }
 
-int interrupt_window_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t interrupt_window_vmexit_handler(struct acrn_vcpu *vcpu)
 {
 	uint32_t value32;
 
@@ -380,9 +380,9 @@ int32_t external_interrupt_vmexit_handler(struct acrn_vcpu *vcpu)
 	return ret;
 }
 
-int acrn_handle_pending_request(struct acrn_vcpu *vcpu)
+int32_t acrn_handle_pending_request(struct acrn_vcpu *vcpu)
 {
-	int ret = 0;
+	int32_t ret = 0;
 	uint32_t tmp;
 	uint32_t intr_info;
 	uint32_t error_code;
@@ -563,12 +563,12 @@ void cancel_event_injection(struct acrn_vcpu *vcpu)
 /*
  * @pre vcpu != NULL
  */
-int exception_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t exception_vmexit_handler(struct acrn_vcpu *vcpu)
 {
 	uint32_t intinfo, int_err_code = 0U;
 	uint32_t exception_vector = VECTOR_INVALID;
 	uint32_t cpl;
-	int status = 0;
+	int32_t status = 0;
 
 	pr_dbg(" Handling guest exception");
 
diff --git a/hypervisor/arch/x86/vmexit.c b/hypervisor/arch/x86/vmexit.c
index ee7e279a2..fcbc5975e 100644
--- a/hypervisor/arch/x86/vmexit.c
+++ b/hypervisor/arch/x86/vmexit.c
@@ -12,9 +12,9 @@
  */
 #define NR_VMX_EXIT_REASONS	65U
 
-static int unhandled_vmexit_handler(struct acrn_vcpu *vcpu);
-static int xsetbv_vmexit_handler(struct acrn_vcpu *vcpu);
-static int wbinvd_vmexit_handler(struct acrn_vcpu *vcpu);
+static int32_t unhandled_vmexit_handler(struct acrn_vcpu *vcpu);
+static int32_t xsetbv_vmexit_handler(struct acrn_vcpu *vcpu);
+static int32_t wbinvd_vmexit_handler(struct acrn_vcpu *vcpu);
 
 /* VM Dispatch table for Exit condition handling */
 static const struct vm_exit_dispatch dispatch_table[NR_VMX_EXIT_REASONS] = {
@@ -152,11 +152,11 @@ static const struct vm_exit_dispatch dispatch_table[NR_VMX_EXIT_REASONS] = {
 		.handler = unhandled_vmexit_handler}
 };
 
-int vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t vmexit_handler(struct acrn_vcpu *vcpu)
 {
 	struct vm_exit_dispatch *dispatch = NULL;
 	uint16_t basic_exit_reason;
-	int ret;
+	int32_t ret;
 
 	if (get_cpu_id() != vcpu->pcpu_id) {
 		pr_fatal("vcpu is not running on its pcpu!");
@@ -228,7 +228,7 @@ int vmexit_handler(struct acrn_vcpu *vcpu)
 	return ret;
 }
 
-static int unhandled_vmexit_handler(struct acrn_vcpu *vcpu)
+static int32_t unhandled_vmexit_handler(struct acrn_vcpu *vcpu)
 {
 	pr_fatal("Error: Unhandled VM exit condition from guest at 0x%016llx ",
 			exec_vmread(VMX_GUEST_RIP));
@@ -243,7 +243,7 @@ static int unhandled_vmexit_handler(struct acrn_vcpu *vcpu)
 	return 0;
 }
 
-int cpuid_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t cpuid_vmexit_handler(struct acrn_vcpu *vcpu)
 {
 	uint64_t rax, rbx, rcx, rdx;
 
@@ -263,7 +263,7 @@ int cpuid_vmexit_handler(struct acrn_vcpu *vcpu)
 	return 0;
 }
 
-int cr_access_vmexit_handler(struct acrn_vcpu *vcpu)
+int32_t cr_access_vmexit_handler(struct acrn_vcpu *vcpu)
 {
 	uint64_t reg;
 	uint32_t idx;
@@ -318,9 +318,9 @@ int cr_access_vmexit_handler(struct acrn_vcpu *vcpu)
  * XSETBV instruction set's the XCR0 that is used to tell for which
  * components states can be saved on a context switch using xsave.
  */
-static int xsetbv_vmexit_handler(struct acrn_vcpu *vcpu)
+static int32_t xsetbv_vmexit_handler(struct acrn_vcpu *vcpu)
 {
-	int idx;
+	int32_t idx;
 	uint64_t val64;
 
 	val64 = exec_vmread(VMX_GUEST_CR4);
@@ -362,7 +362,7 @@ static int xsetbv_vmexit_handler(struct acrn_vcpu *vcpu)
 	return 0;
 }
 
-static int wbinvd_vmexit_handler(struct acrn_vcpu *vcpu)
+static int32_t wbinvd_vmexit_handler(struct acrn_vcpu *vcpu)
 {
 	if (!iommu_snoop_supported(vcpu->vm)) {
 		cache_flush_invalidate_all();
diff --git a/hypervisor/arch/x86/vmx.c b/hypervisor/arch/x86/vmx.c
index 946930dc9..fc90dcdbf 100644
--- a/hypervisor/arch/x86/vmx.c
+++ b/hypervisor/arch/x86/vmx.c
@@ -267,7 +267,7 @@ uint64_t vmx_rdmsr_pat(const struct acrn_vcpu *vcpu)
 	return vcpu_get_guest_msr(vcpu, MSR_IA32_PAT);
 }
 
-int vmx_wrmsr_pat(struct acrn_vcpu *vcpu, uint64_t value)
+int32_t vmx_wrmsr_pat(struct acrn_vcpu *vcpu, uint64_t value)
 {
 	uint32_t i;
 	uint64_t field;
diff --git a/hypervisor/arch/x86/vmx_asm.S b/hypervisor/arch/x86/vmx_asm.S
index c21f534e7..3bd085a16 100644
--- a/hypervisor/arch/x86/vmx_asm.S
+++ b/hypervisor/arch/x86/vmx_asm.S
@@ -30,7 +30,7 @@
 
     .text
 
-/*int vmx_vmrun(struct run_context *context, int launch, int ibrs_type) */
+/*int vmx_vmrun(struct run_context *context, int32_t launch, int32_t ibrs_type) */
    .code64
    .align       8
    .global      vmx_vmrun
diff --git a/hypervisor/arch/x86/vtd.c b/hypervisor/arch/x86/vtd.c
index d58fa6c36..8b82ce05e 100644
--- a/hypervisor/arch/x86/vtd.c
+++ b/hypervisor/arch/x86/vtd.c
@@ -168,14 +168,14 @@ static inline uint16_t vmid_to_domainid(uint16_t vm_id)
 	return vm_id + 1U;
 }
 
-static int dmar_register_hrhd(struct dmar_drhd_rt *dmar_unit);
+static int32_t dmar_register_hrhd(struct dmar_drhd_rt *dmar_unit);
 static struct dmar_drhd_rt *device_to_dmaru(uint16_t segment, uint8_t bus, uint8_t devfun);
-static int register_hrhd_units(void)
+static int32_t register_hrhd_units(void)
 {
 	struct dmar_info *info = get_dmar_info();
 	struct dmar_drhd_rt *drhd_rt;
 	uint32_t i;
-	int ret = 0;
+	int32_t ret = 0;
 
 	if (info == NULL || info->drhd_count == 0U) {
 		pr_fatal("%s: can't find dmar info\n", __func__);
@@ -392,7 +392,7 @@ static void dmar_disable_translation(struct dmar_drhd_rt *dmar_unit)
 	spinlock_release(&(dmar_unit->lock));
 }
 
-static int dmar_register_hrhd(struct dmar_drhd_rt *dmar_unit)
+static int32_t dmar_register_hrhd(struct dmar_drhd_rt *dmar_unit)
 {
 	dev_dbg(ACRN_DBG_IOMMU, "Register dmar uint [%d] @0x%llx", dmar_unit->index, dmar_unit->drhd->reg_base_addr);
 
@@ -707,7 +707,7 @@ static void dmar_fault_handler(uint32_t irq, void *data)
 	uint32_t index;
 	uint32_t record_reg_offset;
 	uint64_t record[2];
-	int loop = 0;
+	int32_t loop = 0;
 
 	dev_dbg(ACRN_DBG_IOMMU, "%s: irq = %d", __func__, irq);
 
@@ -824,7 +824,7 @@ static void dmar_resume(struct dmar_drhd_rt *dmar_unit)
 	dmar_enable(dmar_unit);
 }
 
-static int add_iommu_device(struct iommu_domain *domain, uint16_t segment, uint8_t bus, uint8_t devfun)
+static int32_t add_iommu_device(struct iommu_domain *domain, uint16_t segment, uint8_t bus, uint8_t devfun)
 {
 	struct dmar_drhd_rt *dmar_unit;
 	struct dmar_root_entry *root_table;
@@ -937,7 +937,7 @@ static int add_iommu_device(struct iommu_domain *domain, uint16_t segment, uint8
 	return 0;
 }
 
-static int remove_iommu_device(const struct iommu_domain *domain, uint16_t segment, uint8_t bus, uint8_t devfun)
+static int32_t remove_iommu_device(const struct iommu_domain *domain, uint16_t segment, uint8_t bus, uint8_t devfun)
 {
 	struct dmar_drhd_rt *dmar_unit;
 	struct dmar_root_entry *root_table;
@@ -1045,9 +1045,9 @@ void destroy_iommu_domain(struct iommu_domain *domain)
 	(void)memset(domain, 0U, sizeof(*domain));
 }
 
-int assign_iommu_device(struct iommu_domain *domain, uint8_t bus, uint8_t devfun)
+int32_t assign_iommu_device(struct iommu_domain *domain, uint8_t bus, uint8_t devfun)
 {
-	int status = 0;
+	int32_t status = 0;
 
 	/* TODO: check if the device assigned */
 
@@ -1061,9 +1061,9 @@ int assign_iommu_device(struct iommu_domain *domain, uint8_t bus, uint8_t devfun
 	return add_iommu_device(domain, 0U, bus, devfun);
 }
 
-int unassign_iommu_device(const struct iommu_domain *domain, uint8_t bus, uint8_t devfun)
+int32_t unassign_iommu_device(const struct iommu_domain *domain, uint8_t bus, uint8_t devfun)
 {
-	int status = 0;
+	int32_t status = 0;
 
 	/* TODO: check if the device assigned */
 	status = remove_iommu_device(domain, 0U, bus, devfun);
@@ -1101,9 +1101,9 @@ void resume_iommu(void)
 	do_action_for_iommus(dmar_resume);
 }
 
-int init_iommu(void)
+int32_t init_iommu(void)
 {
-	int ret;
+	int32_t ret;
 
 	ret = register_hrhd_units();
 	if (ret != 0) {
diff --git a/hypervisor/boot/acpi.c b/hypervisor/boot/acpi.c
index ebec4905e..aeaa5be75 100644
--- a/hypervisor/boot/acpi.c
+++ b/hypervisor/boot/acpi.c
@@ -103,11 +103,11 @@ struct acpi_madt_local_apic {
 static void *global_rsdp;
 
 static struct acpi_table_rsdp*
-biosacpi_search_rsdp(char *base, int length)
+biosacpi_search_rsdp(char *base, int32_t length)
 {
 	struct acpi_table_rsdp *rsdp;
 	uint8_t *cp, sum;
-	int ofs, idx;
+	int32_t ofs, idx;
 
 	/* search on 16-byte boundaries */
 	for (ofs = 0; ofs < length; ofs += 16) {
diff --git a/hypervisor/boot/dmar_parse.c b/hypervisor/boot/dmar_parse.c
index 022258fed..2f38c5d31 100644
--- a/hypervisor/boot/dmar_parse.c
+++ b/hypervisor/boot/dmar_parse.c
@@ -55,7 +55,7 @@ struct acpi_dmar_hardware_unit {
 };
 
 struct find_iter_args {
-	int i;
+	int32_t i;
 	struct acpi_dmar_hardware_unit *res;
 };
 
@@ -72,10 +72,10 @@ struct acpi_dmar_device_scope {
 	uint8_t                   bus;
 };
 
-typedef int (*dmar_iter_t)(struct acpi_dmar_header*, void*);
+typedef int32_t (*dmar_iter_t)(struct acpi_dmar_header*, void*);
 
 static struct dmar_info dmar_info_parsed;
-static int dmar_unit_cnt;
+static int32_t dmar_unit_cnt;
 
 static void
 dmar_iterate_tbl(dmar_iter_t iter, void *arg)
@@ -105,7 +105,7 @@ dmar_iterate_tbl(dmar_iter_t iter, void *arg)
 	}
 }
 
-static int
+static int32_t
 drhd_count_iter(struct acpi_dmar_header *dmar_header, __unused void *arg)
 {
 	if (dmar_header->type == ACPI_DMAR_TYPE_HARDWARE_UNIT)
@@ -113,7 +113,7 @@ drhd_count_iter(struct acpi_dmar_header *dmar_header, __unused void *arg)
 	return 1;
 }
 
-static int
+static int32_t
 drhd_find_iter(struct acpi_dmar_header *dmar_header, void *arg)
 {
 	struct find_iter_args *args;
@@ -131,7 +131,7 @@ drhd_find_iter(struct acpi_dmar_header *dmar_header, void *arg)
 }
 
 static struct acpi_dmar_hardware_unit *
-drhd_find_by_index(int idx)
+drhd_find_by_index(int32_t idx)
 {
 	struct find_iter_args args;
 
@@ -154,10 +154,10 @@ static uint8_t get_secondary_bus(uint8_t bus, uint8_t dev, uint8_t func)
 }
 
 static uint16_t
-dmar_path_bdf(int path_len, int busno,
+dmar_path_bdf(int32_t path_len, int32_t busno,
 	const struct acpi_dmar_pci_path *path)
 {
-	int i;
+	int32_t i;
 	uint8_t bus;
 	uint8_t dev;
 	uint8_t fun;
@@ -177,16 +177,16 @@ dmar_path_bdf(int path_len, int busno,
 }
 
 
-static int
+static int32_t
 handle_dmar_devscope(struct dmar_dev_scope *dev_scope,
-	void *addr, int remaining)
+	void *addr, int32_t remaining)
 {
-	int path_len;
+	int32_t path_len;
 	uint16_t bdf;
 	struct acpi_dmar_pci_path *path;
 	struct acpi_dmar_device_scope *apci_devscope = addr;
 
-	if (remaining < (int)sizeof(struct acpi_dmar_device_scope))
+	if (remaining < (int32_t)sizeof(struct acpi_dmar_device_scope))
 		return -1;
 
 	if (remaining < apci_devscope->length)
@@ -226,13 +226,13 @@ get_drhd_dev_scope_cnt(struct acpi_dmar_hardware_unit *drhd)
 	return count;
 }
 
-static int
+static int32_t
 handle_one_drhd(struct acpi_dmar_hardware_unit *acpi_drhd,
 		struct dmar_drhd *drhd)
 {
 	struct dmar_dev_scope *dev_scope;
 	struct acpi_dmar_device_scope *ads;
-	int remaining, consumed;
+	int32_t remaining, consumed;
 	char *cp;
 	uint32_t dev_count;
 
@@ -291,9 +291,9 @@ handle_one_drhd(struct acpi_dmar_hardware_unit *acpi_drhd,
 	return 0;
 }
 
-int parse_dmar_table(void)
+int32_t parse_dmar_table(void)
 {
-	int i;
+	int32_t i;
 	struct acpi_dmar_hardware_unit *acpi_drhd;
 
 	/* find out how many dmar units */
diff --git a/hypervisor/boot/sbl/multiboot.c b/hypervisor/boot/sbl/multiboot.c
index 89a86c793..f97084ac5 100644
--- a/hypervisor/boot/sbl/multiboot.c
+++ b/hypervisor/boot/sbl/multiboot.c
@@ -17,7 +17,7 @@
 #define MAX_BOOT_PARAMS_LEN 64U
 
 #ifdef CONFIG_PARTITION_MODE
-int init_vm_boot_info(struct acrn_vm *vm)
+int32_t init_vm_boot_info(struct acrn_vm *vm)
 {
 	struct multiboot_module *mods = NULL;
 	struct multiboot_info *mbi = NULL;
@@ -104,7 +104,7 @@ static void parse_other_modules(struct acrn_vm *vm,
 			void *load_addr = gpa2hva(vm,
 				(uint64_t)vm->sw.linux_info.bootargs_load_addr);
 			uint32_t args_size = vm->sw.linux_info.bootargs_size;
-			static int copy_once = 1;
+			static int32_t copy_once = 1;
 
 			start = end + 1; /*it is fw name for boot args */
 			snprintf(dyn_bootargs, 100U, " %s=0x%x@0x%x ",
@@ -164,7 +164,7 @@ static void *get_kernel_load_addr(void *kernel_src_addr)
  * @pre vm != NULL
  * @pre is_vm0(vm) == true
  */
-int init_vm_boot_info(struct acrn_vm *vm)
+int32_t init_vm_boot_info(struct acrn_vm *vm)
 {
 	struct multiboot_module *mods = NULL;
 	struct multiboot_info *mbi = NULL;
diff --git a/hypervisor/bsp/uefi/cmdline.c b/hypervisor/bsp/uefi/cmdline.c
index 01d2b35fe..68dd3dfdc 100644
--- a/hypervisor/bsp/uefi/cmdline.c
+++ b/hypervisor/bsp/uefi/cmdline.c
@@ -28,12 +28,12 @@ enum IDX_CMD {
 	IDX_MAX_CMD,
 };
 
-static void handle_cmd(const char *cmd, int len)
+static void handle_cmd(const char *cmd, int32_t len)
 {
-	int i;
+	int32_t i;
 
 	for (i = 0; i < IDX_MAX_CMD; i++) {
-		int tmp = strnlen_s(cmd_list[i], MAX_CMD_LEN);
+		int32_t tmp = strnlen_s(cmd_list[i], MAX_CMD_LEN);
 
 		/*cmd prefix should be same with one in cmd_list */
 		if (len < tmp)
@@ -62,7 +62,7 @@ static void handle_cmd(const char *cmd, int len)
 	}
 }
 
-int parse_hv_cmdline(void)
+int32_t parse_hv_cmdline(void)
 {
 	const char *start;
 	const char *end;
diff --git a/hypervisor/bsp/uefi/efi/boot.c b/hypervisor/bsp/uefi/efi/boot.c
index b922e9452..8604385ca 100644
--- a/hypervisor/bsp/uefi/efi/boot.c
+++ b/hypervisor/bsp/uefi/efi/boot.c
@@ -77,7 +77,7 @@ EFI_STATUS construct_mbi(EFI_PHYSICAL_ADDRESS hv_hpa)
 	struct multiboot_info *mbi;
 	struct multiboot_mmap *mmap;
 	struct efi_context *efi_ctx;
-	int i, j;
+	int32_t i, j;
 
 	mbi = MBOOT_INFO_PTR(hv_hpa);
 	mmap = MBOOT_MMAP_PTR(hv_hpa);
@@ -202,7 +202,7 @@ switch_to_guest_mode(EFI_HANDLE image, EFI_PHYSICAL_ADDRESS hv_hpa)
 	struct multiboot_info *mbi;
 	struct efi_context *efi_ctx;
 	struct acpi_table_rsdp *rsdp = NULL;
-	int i;
+	int32_t i;
 	EFI_CONFIGURATION_TABLE *config_table;
 
 	mbi = MBOOT_INFO_PTR(hv_hpa);
diff --git a/hypervisor/bsp/uefi/efi/boot.h b/hypervisor/bsp/uefi/efi/boot.h
index 94107129a..d1c5f29dd 100644
--- a/hypervisor/bsp/uefi/efi/boot.h
+++ b/hypervisor/bsp/uefi/efi/boot.h
@@ -67,7 +67,7 @@
 }
 
 EFI_STATUS get_pe_section(CHAR8 *base, char *section, UINTN *vaddr, UINTN *size);
-typedef void(*hv_func)(int, struct multiboot_info*);
+typedef void(*hv_func)(int32_t, struct multiboot_info*);
 
 /*
  * We allocate memory for the following struct together with hyperivosr itself
diff --git a/hypervisor/bsp/uefi/efi/stdlib.h b/hypervisor/bsp/uefi/efi/stdlib.h
index 7106acf18..fa1d8e748 100644
--- a/hypervisor/bsp/uefi/efi/stdlib.h
+++ b/hypervisor/bsp/uefi/efi/stdlib.h
@@ -48,7 +48,7 @@
 static inline void memset(void *dstv, char ch, UINTN size)
 {
 	char *dst = dstv;
-	int i;
+	int32_t i;
 
 	for (i = 0; i < size; i++)
 		dst[i] = ch;
@@ -56,15 +56,15 @@ static inline void memset(void *dstv, char ch, UINTN size)
 
 static inline void memcpy(char *dst, const char *src, UINTN size)
 {
-	int i;
+	int32_t i;
 
 	for (i = 0; i < size; i++)
 		*dst++ = *src++;
 }
 
-static inline int strlen(const char *str)
+static inline int32_t strlen(const char *str)
 {
-	int len;
+	int32_t len;
 
 	len = 0;
 	while (*str++)
diff --git a/hypervisor/bsp/uefi/uefi.c b/hypervisor/bsp/uefi/uefi.c
index f753d09fd..2c3217e83 100644
--- a/hypervisor/bsp/uefi/uefi.c
+++ b/hypervisor/bsp/uefi/uefi.c
@@ -14,9 +14,9 @@ static void efi_init(void);
 
 struct efi_context* efi_ctx = NULL;
 struct lapic_regs uefi_lapic_regs;
-static int efi_initialized;
+static int32_t efi_initialized;
 
-void efi_spurious_handler(int vector)
+void efi_spurious_handler(int32_t vector)
 {
 	struct acrn_vcpu* vcpu;
 
@@ -33,9 +33,9 @@ void efi_spurious_handler(int vector)
 	return;
 }
 
-int uefi_sw_loader(struct acrn_vm *vm)
+int32_t uefi_sw_loader(struct acrn_vm *vm)
 {
-	int ret = 0;
+	int32_t ret = 0;
 	struct acrn_vcpu *vcpu = get_primary_vcpu(vm);
 	struct acrn_vcpu_regs *vcpu_regs = &boot_context;
 
diff --git a/hypervisor/common/hypercall.c b/hypervisor/common/hypercall.c
index 67fa8cda4..746466649 100644
--- a/hypervisor/common/hypercall.c
+++ b/hypervisor/common/hypercall.c
@@ -613,7 +613,7 @@ int32_t hcall_set_vm_memory_regions(struct acrn_vm *vm, uint64_t param)
 
 	idx = 0U;
 	while (idx < regions.mr_num) {
-		int ret;
+		int32_t ret;
 
 		if (copy_from_gpa(vm, &mr, regions.regions_gpa + idx * sizeof(mr), sizeof(mr)) != 0) {
 			pr_err("%s: Copy mr entry fail from vm\n", __func__);
diff --git a/hypervisor/common/schedule.c b/hypervisor/common/schedule.c
index d00fb759a..bf17edfb8 100644
--- a/hypervisor/common/schedule.c
+++ b/hypervisor/common/schedule.c
@@ -106,7 +106,7 @@ void make_reschedule_request(const struct acrn_vcpu *vcpu)
 	}
 }
 
-int need_reschedule(uint16_t pcpu_id)
+int32_t need_reschedule(uint16_t pcpu_id)
 {
 	struct sched_context *ctx = &per_cpu(sched_ctx, pcpu_id);
 
@@ -160,7 +160,7 @@ void make_pcpu_offline(uint16_t pcpu_id)
 	}
 }
 
-int need_offline(uint16_t pcpu_id)
+int32_t need_offline(uint16_t pcpu_id)
 {
 	struct sched_context *ctx = &per_cpu(sched_ctx, pcpu_id);
 
diff --git a/hypervisor/common/static_checks.c b/hypervisor/common/static_checks.c
index c194d0088..730c3eb39 100644
--- a/hypervisor/common/static_checks.c
+++ b/hypervisor/common/static_checks.c
@@ -8,6 +8,6 @@
 #define CAT__(A,B) A ## B
 #define CAT_(A,B) CAT__(A,B)
 #define CTASSERT(expr) \
-typedef int CAT_(CTA_DummyType,__LINE__)[(expr) ? 1 : -1]
+typedef int32_t CAT_(CTA_DummyType,__LINE__)[(expr) ? 1 : -1]
 
 CTASSERT(sizeof(struct vhm_request) == (4096U/VHM_REQUEST_MAX));
diff --git a/hypervisor/common/vm_load.c b/hypervisor/common/vm_load.c
index f7d812552..88dbff997 100644
--- a/hypervisor/common/vm_load.c
+++ b/hypervisor/common/vm_load.c
@@ -73,7 +73,7 @@ static uint64_t create_zero_page(struct acrn_vm *vm)
 	return gpa;
 }
 
-int general_sw_loader(struct acrn_vm *vm)
+int32_t general_sw_loader(struct acrn_vm *vm)
 {
 	int32_t ret = 0;
 	void *hva;
diff --git a/hypervisor/debug/dump.c b/hypervisor/debug/dump.c
index 75ca914aa..38dd40a20 100644
--- a/hypervisor/debug/dump.c
+++ b/hypervisor/debug/dump.c
@@ -133,7 +133,7 @@ static void show_guest_call_trace(struct acrn_vcpu *vcpu)
 {
 	uint64_t bp;
 	uint64_t count = 0UL;
-	int err;
+	int32_t err;
 	uint32_t err_code;
 
 	bp = vcpu_get_gpreg(vcpu, CPU_REG_RBP);
diff --git a/hypervisor/debug/npk_log.c b/hypervisor/debug/npk_log.c
index 1cb82efde..3a05b1f26 100644
--- a/hypervisor/debug/npk_log.c
+++ b/hypervisor/debug/npk_log.c
@@ -42,9 +42,9 @@ struct npk_chan {
 	uint32_t unused;
 } __packed;
 
-static inline int npk_write(const char *value, void *addr, size_t sz)
+static inline int32_t npk_write(const char *value, void *addr, size_t sz)
 {
-	int ret = -1;
+	int32_t ret = -1;
 
 	if (sz >= 8U) {
 		mmio_write64(*(uint64_t *)value, addr);
@@ -123,7 +123,7 @@ void npk_log_write(const char *buf, size_t buf_len)
 	uint32_t cpu_id = get_cpu_id();
 	struct npk_chan *channel = (struct npk_chan *)base;
 	const char *p = buf;
-	int sz;
+	int32_t sz;
 	uint32_t ref;
 	uint16_t len;
 
diff --git a/hypervisor/debug/profiling.c b/hypervisor/debug/profiling.c
index d81cab635..9c1490417 100644
--- a/hypervisor/debug/profiling.c
+++ b/hypervisor/debug/profiling.c
@@ -215,7 +215,7 @@ static void profiling_disable_pmu(void)
 /*
  * Writes specified size of data into sbuf
  */
-static int profiling_sbuf_put_variable(struct shared_buf *sbuf,
+static int32_t profiling_sbuf_put_variable(struct shared_buf *sbuf,
 					uint8_t *data, uint32_t size)
 {
 	uint32_t remaining_space, offset, next_tail;
@@ -287,18 +287,18 @@ static int profiling_sbuf_put_variable(struct shared_buf *sbuf,
 
 	sbuf->tail = next_tail;
 
-	return (int)size;
+	return (int32_t)size;
 }
 
 /*
  * Read profiling data and transferred to SOS
  * Drop transfer of profiling data if sbuf is full/insufficient and log it
  */
-static int profiling_generate_data(int32_t collector, uint32_t type)
+static int32_t profiling_generate_data(int32_t collector, uint32_t type)
 {
 	uint64_t i;
 	uint32_t remaining_space = 0U;
-	int 	ret = 0;
+	int32_t 	ret = 0;
 	struct data_header pkt_header;
 	uint64_t payload_size = 0UL;
 	void *payload = NULL;
diff --git a/hypervisor/debug/sbuf.c b/hypervisor/debug/sbuf.c
index 0182f6a69..33b1e7eec 100644
--- a/hypervisor/debug/sbuf.c
+++ b/hypervisor/debug/sbuf.c
@@ -92,7 +92,7 @@ uint32_t sbuf_put(struct shared_buf *sbuf, uint8_t *data)
 	return sbuf->ele_size;
 }
 
-int sbuf_share_setup(uint16_t pcpu_id, uint32_t sbuf_id, uint64_t *hva)
+int32_t sbuf_share_setup(uint16_t pcpu_id, uint32_t sbuf_id, uint64_t *hva)
 {
 	if ((pcpu_id >= phys_cpu_num) ||
 			(sbuf_id >= ACRN_SBUF_ID_MAX)) {
diff --git a/hypervisor/debug/shell.c b/hypervisor/debug/shell.c
index 5bca53c89..5270eb724 100644
--- a/hypervisor/debug/shell.c
+++ b/hypervisor/debug/shell.c
@@ -19,19 +19,19 @@ static char shell_log_buf[SHELL_LOG_BUF_SIZE];
  */
 #define SHELL_INPUT_LINE_OTHER(v)	(((v) + 1U) & 0x1U)
 
-static int shell_cmd_help(__unused int argc, __unused char **argv);
-static int shell_list_vm(__unused int argc, __unused char **argv);
-static int shell_list_vcpu(__unused int argc, __unused char **argv);
-static int shell_vcpu_dumpreg(int argc, char **argv);
-static int shell_dumpmem(int argc, char **argv);
-static int shell_to_sos_console(int argc, char **argv);
-static int shell_show_cpu_int(__unused int argc, __unused char **argv);
-static int shell_show_ptdev_info(__unused int argc, __unused char **argv);
-static int shell_show_vioapic_info(int argc, char **argv);
-static int shell_show_ioapic_info(__unused int argc, __unused char **argv);
-static int shell_loglevel(int argc, char **argv);
-static int shell_cpuid(int argc, char **argv);
-static int shell_trigger_crash(int argc, char **argv);
+static int32_t shell_cmd_help(__unused int32_t argc, __unused char **argv);
+static int32_t shell_list_vm(__unused int32_t argc, __unused char **argv);
+static int32_t shell_list_vcpu(__unused int32_t argc, __unused char **argv);
+static int32_t shell_vcpu_dumpreg(int32_t argc, char **argv);
+static int32_t shell_dumpmem(int32_t argc, char **argv);
+static int32_t shell_to_sos_console(int32_t argc, char **argv);
+static int32_t shell_show_cpu_int(__unused int32_t argc, __unused char **argv);
+static int32_t shell_show_ptdev_info(__unused int32_t argc, __unused char **argv);
+static int32_t shell_show_vioapic_info(int32_t argc, char **argv);
+static int32_t shell_show_ioapic_info(__unused int32_t argc, __unused char **argv);
+static int32_t shell_loglevel(int32_t argc, char **argv);
+static int32_t shell_cpuid(int32_t argc, char **argv);
+static int32_t shell_trigger_crash(int32_t argc, char **argv);
 
 static struct shell_cmd shell_cmds[] = {
 	{
@@ -122,7 +122,7 @@ uint16_t npk_loglevel = CONFIG_NPK_LOGLEVEL_DEFAULT;
 static struct shell hv_shell;
 static struct shell *p_shell = &hv_shell;
 
-static int string_to_argv(char *argv_str, void *p_argv_mem,
+static int32_t string_to_argv(char *argv_str, void *p_argv_mem,
 		__unused uint32_t argv_mem_size,
 		uint32_t *p_argc, char ***p_argv)
 {
@@ -316,13 +316,13 @@ static bool shell_input_line(void)
 	return done;
 }
 
-static int shell_process_cmd(const char *p_input_line)
+static int32_t shell_process_cmd(const char *p_input_line)
 {
-	int status = -EINVAL;
+	int32_t status = -EINVAL;
 	struct shell_cmd *p_cmd;
 	char cmd_argv_str[SHELL_CMD_MAX_LEN + 1U];
-	int cmd_argv_mem[sizeof(char *) * ((SHELL_CMD_MAX_LEN + 1U) >> 1U)];
-	int cmd_argc;
+	int32_t cmd_argv_mem[sizeof(char *) * ((SHELL_CMD_MAX_LEN + 1U) >> 1U)];
+	int32_t cmd_argc;
 	char **cmd_argv;
 
 	/* Copy the input line INTo an argument string to become part of the
@@ -361,9 +361,9 @@ static int shell_process_cmd(const char *p_input_line)
 	return status;
 }
 
-static int shell_process(void)
+static int32_t shell_process(void)
 {
-	int status;
+	int32_t status;
 	char *p_input_line;
 
 	/* Check for the repeat command character in active input line.
@@ -435,7 +435,7 @@ void shell_init(void)
 
 #define SHELL_ROWS	10
 #define MAX_INDENT_LEN	16U
-static int shell_cmd_help(__unused int argc, __unused char **argv)
+static int32_t shell_cmd_help(__unused int32_t argc, __unused char **argv)
 {
 	uint16_t spaces;
 	struct shell_cmd *p_cmd = NULL;
@@ -508,7 +508,7 @@ static int shell_cmd_help(__unused int argc, __unused char **argv)
 	return 0;
 }
 
-static int shell_list_vm(__unused int argc, __unused char **argv)
+static int32_t shell_list_vm(__unused int32_t argc, __unused char **argv)
 {
 	char temp_str[MAX_STR_SIZE];
 	struct acrn_vm *vm;
@@ -550,7 +550,7 @@ static int shell_list_vm(__unused int argc, __unused char **argv)
 	return 0;
 }
 
-static int shell_list_vcpu(__unused int argc, __unused char **argv)
+static int32_t shell_list_vcpu(__unused int32_t argc, __unused char **argv)
 {
 	char temp_str[MAX_STR_SIZE];
 	struct acrn_vm *vm;
@@ -607,7 +607,7 @@ static int shell_list_vcpu(__unused int argc, __unused char **argv)
 /* the input 'data' must != NULL and indicate a vcpu structure pointer */
 static void vcpu_dumpreg(void *data)
 {
-	int status;
+	int32_t status;
 	uint64_t i, fault_addr, tmp[DUMPREG_SP_SIZE];
 	uint32_t err_code = 0;
 	struct vcpu_dump *dump = data;
@@ -689,9 +689,9 @@ overflow:
 	printf("buffer size could not be enough! please check!\n");
 }
 
-static int shell_vcpu_dumpreg(int argc, char **argv)
+static int32_t shell_vcpu_dumpreg(int32_t argc, char **argv)
 {
-	int status = 0;
+	int32_t status = 0;
 	uint16_t vm_id;
 	uint16_t vcpu_id;
 	struct acrn_vm *vm;
@@ -744,7 +744,7 @@ out:
 }
 
 #define MAX_MEMDUMP_LEN		(32U * 8U)
-static int shell_dumpmem(int argc, char **argv)
+static int32_t shell_dumpmem(int32_t argc, char **argv)
 {
 	uint64_t addr;
 	uint64_t *ptr;
@@ -788,7 +788,7 @@ static int shell_dumpmem(int argc, char **argv)
 	return 0;
 }
 
-static int shell_to_sos_console(__unused int argc, __unused char **argv)
+static int32_t shell_to_sos_console(__unused int32_t argc, __unused char **argv)
 {
 	char temp_str[TEMP_STR_SIZE];
 	uint16_t guest_no = 0U;
@@ -894,7 +894,7 @@ overflow:
 	printf("buffer size could not be enough! please check!\n");
 }
 
-static int shell_show_cpu_int(__unused int argc, __unused char **argv)
+static int32_t shell_show_cpu_int(__unused int32_t argc, __unused char **argv)
 {
 	get_cpu_interrupt_info(shell_log_buf, SHELL_LOG_BUF_SIZE);
 	shell_puts(shell_log_buf);
@@ -1010,7 +1010,7 @@ overflow:
 	printf("buffer size could not be enough! please check!\n");
 }
 
-static int shell_show_ptdev_info(__unused int argc, __unused char **argv)
+static int32_t shell_show_ptdev_info(__unused int32_t argc, __unused char **argv)
 {
 	get_ptdev_info(shell_log_buf, SHELL_LOG_BUF_SIZE);
 	shell_puts(shell_log_buf);
@@ -1074,7 +1074,7 @@ overflow:
 	printf("buffer size could not be enough! please check!\n");
 }
 
-static int shell_show_vioapic_info(int argc, char **argv)
+static int32_t shell_show_vioapic_info(int32_t argc, char **argv)
 {
 	uint16_t vmid;
 	int32_t ret;
@@ -1115,7 +1115,7 @@ static void get_rte_info(union ioapic_rte rte, bool *mask, bool *irr,
  *				interrupt info
  * @param[inout]	str_arg	Pointer to the output information
  */
-static int get_ioapic_info(char *str_arg, size_t str_max_len)
+static int32_t get_ioapic_info(char *str_arg, size_t str_max_len)
 {
 	char *str = str_arg;
 	uint32_t irq;
@@ -1164,9 +1164,9 @@ overflow:
 	return 0;
 }
 
-static int shell_show_ioapic_info(__unused int argc, __unused char **argv)
+static int32_t shell_show_ioapic_info(__unused int32_t argc, __unused char **argv)
 {
-	int err = 0;
+	int32_t err = 0;
 
 	err = get_ioapic_info(shell_log_buf, SHELL_LOG_BUF_SIZE);
 	shell_puts(shell_log_buf);
@@ -1174,7 +1174,7 @@ static int shell_show_ioapic_info(__unused int argc, __unused char **argv)
 	return err;
 }
 
-static int shell_loglevel(int argc, char **argv)
+static int32_t shell_loglevel(int32_t argc, char **argv)
 {
 	char str[MAX_STR_SIZE] = {0};
 
@@ -1201,7 +1201,7 @@ static int shell_loglevel(int argc, char **argv)
 	return 0;
 }
 
-static int shell_cpuid(int argc, char **argv)
+static int32_t shell_cpuid(int32_t argc, char **argv)
 {
 	char str[MAX_STR_SIZE] = {0};
 	uint32_t leaf, subleaf = 0;
@@ -1228,7 +1228,7 @@ static int shell_cpuid(int argc, char **argv)
 	return 0;
 }
 
-static int shell_trigger_crash(int argc, char **argv)
+static int32_t shell_trigger_crash(int32_t argc, char **argv)
 {
 	char str[MAX_STR_SIZE] = {0};
 
diff --git a/hypervisor/debug/shell_priv.h b/hypervisor/debug/shell_priv.h
index 35bede3bb..17d46ebf6 100644
--- a/hypervisor/debug/shell_priv.h
+++ b/hypervisor/debug/shell_priv.h
@@ -13,7 +13,7 @@
 #define SHELL_STRING_MAX_LEN		(PAGE_SIZE << 2U)
 
 /* Shell Command Function */
-typedef int (*shell_cmd_fn_t)(int argc, char **argv);
+typedef int32_t (*shell_cmd_fn_t)(int32_t argc, char **argv);
 
 /* Shell Command */
 struct shell_cmd {
diff --git a/hypervisor/dm/vioapic.c b/hypervisor/dm/vioapic.c
index 7f10e9964..242eea0cf 100644
--- a/hypervisor/dm/vioapic.c
+++ b/hypervisor/dm/vioapic.c
@@ -536,13 +536,13 @@ vioapic_pincount(const struct acrn_vm *vm)
 	return ret;
 }
 
-int vioapic_mmio_access_handler(struct io_request *io_req, void *handler_private_data)
+int32_t vioapic_mmio_access_handler(struct io_request *io_req, void *handler_private_data)
 {
 	struct acrn_vm *vm = (struct acrn_vm *)handler_private_data;
 	struct acrn_vioapic *vioapic;
 	struct mmio_request *mmio = &io_req->reqs.mmio;
 	uint64_t gpa = mmio->address;
-	int ret = 0;
+	int32_t ret = 0;
 
 	vioapic = vm_ioapic(vm);
 
diff --git a/hypervisor/dm/vpci/hostbridge.c b/hypervisor/dm/vpci/hostbridge.c
index e0f7f3eb9..fc9b90145 100644
--- a/hypervisor/dm/vpci/hostbridge.c
+++ b/hypervisor/dm/vpci/hostbridge.c
@@ -37,7 +37,7 @@
 #include <hypervisor.h>
 #include "pci_priv.h"
 
-static int vdev_hostbridge_init(struct pci_vdev *vdev)
+static int32_t vdev_hostbridge_init(struct pci_vdev *vdev)
 {
 	/* PCI config space */
 	pci_vdev_write_cfg_u16(vdev, PCIR_VENDOR, (uint16_t)0x8086U);
@@ -84,12 +84,12 @@ static int vdev_hostbridge_init(struct pci_vdev *vdev)
 	return 0;
 }
 
-static int vdev_hostbridge_deinit(__unused struct pci_vdev *vdev)
+static int32_t vdev_hostbridge_deinit(__unused struct pci_vdev *vdev)
 {
 	return 0;
 }
 
-static int vdev_hostbridge_cfgread(struct pci_vdev *vdev, uint32_t offset,
+static int32_t vdev_hostbridge_cfgread(struct pci_vdev *vdev, uint32_t offset,
 	uint32_t bytes, uint32_t *val)
 {
 	/* Assumption: access needed to be aligned on 1/2/4 bytes */
@@ -103,7 +103,7 @@ static int vdev_hostbridge_cfgread(struct pci_vdev *vdev, uint32_t offset,
 	return 0;
 }
 
-static int vdev_hostbridge_cfgwrite(struct pci_vdev *vdev, uint32_t offset,
+static int32_t vdev_hostbridge_cfgwrite(struct pci_vdev *vdev, uint32_t offset,
 	uint32_t bytes, uint32_t val)
 {
 	/* Assumption: access needed to be aligned on 1/2/4 bytes */
diff --git a/hypervisor/dm/vpci/msix.c b/hypervisor/dm/vpci/msix.c
index eb58bc19d..e2a0ac4f8 100644
--- a/hypervisor/dm/vpci/msix.c
+++ b/hypervisor/dm/vpci/msix.c
@@ -48,12 +48,12 @@ static inline bool msixtable_access(struct pci_vdev *vdev, uint32_t offset)
 	return in_range(offset, vdev->msix.table_offset, vdev->msix.table_count * MSIX_TABLE_ENTRY_SIZE);
 }
 
-static int vmsix_remap_entry(struct pci_vdev *vdev, uint32_t index, bool enable)
+static int32_t vmsix_remap_entry(struct pci_vdev *vdev, uint32_t index, bool enable)
 {
 	struct msix_table_entry *pentry;
 	struct ptirq_msi_info info;
 	uint64_t hva;
-	int ret;
+	int32_t ret;
 
 	info.is_msix = 1;
 	info.vmsi_addr = vdev->msix.tables[index].addr;
@@ -94,10 +94,10 @@ static inline void enable_disable_msix(struct pci_vdev *vdev, bool enable)
 }
 
 /* Do MSI-X remap for all MSI-X table entries in the target device */
-static int vmsix_remap(struct pci_vdev *vdev, bool enable)
+static int32_t vmsix_remap(struct pci_vdev *vdev, bool enable)
 {
 	uint32_t index;
-	int ret;
+	int32_t ret;
 
 	/* disable MSI-X during configuration */
 	enable_disable_msix(vdev, false);
@@ -119,10 +119,10 @@ static int vmsix_remap(struct pci_vdev *vdev, bool enable)
 }
 
 /* Do MSI-X remap for one MSI-X table entry only */
-static int vmsix_remap_one_entry(struct pci_vdev *vdev, uint32_t index, bool enable)
+static int32_t vmsix_remap_one_entry(struct pci_vdev *vdev, uint32_t index, bool enable)
 {
 	uint32_t msgctrl;
-	int ret;
+	int32_t ret;
 
 	/* disable MSI-X during configuration */
 	enable_disable_msix(vdev, false);
@@ -144,7 +144,7 @@ static int vmsix_remap_one_entry(struct pci_vdev *vdev, uint32_t index, bool ena
 	return ret;
 }
 
-static int vmsix_cfgread(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t *val)
+static int32_t vmsix_cfgread(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t *val)
 {
 	int32_t ret;
 	/* For PIO access, we emulate Capability Structures only */
@@ -159,7 +159,7 @@ static int vmsix_cfgread(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes,
 	return ret;
 }
 
-static int vmsix_cfgwrite(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t val)
+static int32_t vmsix_cfgwrite(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t val)
 {
 	uint32_t msgctrl;
 	int32_t ret;
@@ -257,7 +257,7 @@ static void vmsix_table_rw(struct pci_vdev *vdev, struct mmio_request *mmio, uin
 	}
 }
 
-static int vmsix_table_mmio_access_handler(struct io_request *io_req, void *handler_private_data)
+static int32_t vmsix_table_mmio_access_handler(struct io_request *io_req, void *handler_private_data)
 {
 	struct mmio_request *mmio = &io_req->reqs.mmio;
 	struct pci_vdev *vdev;
@@ -344,7 +344,7 @@ static void decode_msix_table_bar(struct pci_vdev *vdev)
 	}
 }
 
-static int vmsix_init(struct pci_vdev *vdev)
+static int32_t vmsix_init(struct pci_vdev *vdev)
 {
 	uint32_t msgctrl;
 	uint32_t table_info, i;
@@ -407,7 +407,7 @@ static int vmsix_init(struct pci_vdev *vdev)
 	return ret;
 }
 
-static int vmsix_deinit(struct pci_vdev *vdev)
+static int32_t vmsix_deinit(struct pci_vdev *vdev)
 {
 	vdev->msix.intercepted_size = 0U;
 
diff --git a/hypervisor/dm/vpci/partition_mode.c b/hypervisor/dm/vpci/partition_mode.c
index c4e72ab41..be2392065 100644
--- a/hypervisor/dm/vpci/partition_mode.c
+++ b/hypervisor/dm/vpci/partition_mode.c
@@ -36,7 +36,7 @@ static struct pci_vdev *partition_mode_find_vdev(struct vpci *vpci, union pci_bd
 {
 	struct vpci_vdev_array *vdev_array;
 	struct pci_vdev *vdev;
-	int i;
+	int32_t i;
 
 	vdev_array = vpci->vm->vm_desc->vpci_vdev_array;
 	for (i = 0; i < vdev_array->num_pci_vdev; i++) {
@@ -49,12 +49,12 @@ static struct pci_vdev *partition_mode_find_vdev(struct vpci *vpci, union pci_bd
 	return NULL;
 }
 
-static int partition_mode_vpci_init(struct acrn_vm *vm)
+static int32_t partition_mode_vpci_init(struct acrn_vm *vm)
 {
 	struct vpci_vdev_array *vdev_array;
 	struct vpci *vpci = &vm->vpci;
 	struct pci_vdev *vdev;
-	int i;
+	int32_t i;
 
 	vdev_array = vm->vm_desc->vpci_vdev_array;
 
@@ -77,7 +77,7 @@ static void partition_mode_vpci_deinit(struct acrn_vm *vm)
 {
 	struct vpci_vdev_array *vdev_array;
 	struct pci_vdev *vdev;
-	int i;
+	int32_t i;
 
 	vdev_array = vm->vm_desc->vpci_vdev_array;
 
diff --git a/hypervisor/dm/vpci/pci_pt.c b/hypervisor/dm/vpci/pci_pt.c
index 36f2ee00f..e66e1e341 100644
--- a/hypervisor/dm/vpci/pci_pt.c
+++ b/hypervisor/dm/vpci/pci_pt.c
@@ -37,7 +37,7 @@ static inline uint32_t pci_bar_base(uint32_t bar)
 	return bar & PCIM_BAR_MEM_BASE;
 }
 
-static int vdev_pt_init_validate(struct pci_vdev *vdev)
+static int32_t vdev_pt_init_validate(struct pci_vdev *vdev)
 {
 	uint32_t idx;
 
@@ -53,9 +53,9 @@ static int vdev_pt_init_validate(struct pci_vdev *vdev)
 	return 0;
 }
 
-static int vdev_pt_init(struct pci_vdev *vdev)
+static int32_t vdev_pt_init(struct pci_vdev *vdev)
 {
-	int ret;
+	int32_t ret;
 	struct acrn_vm *vm = vdev->vpci->vm;
 	uint16_t pci_command;
 
@@ -86,9 +86,9 @@ static int vdev_pt_init(struct pci_vdev *vdev)
 	return ret;
 }
 
-static int vdev_pt_deinit(struct pci_vdev *vdev)
+static int32_t vdev_pt_deinit(struct pci_vdev *vdev)
 {
-	int ret;
+	int32_t ret;
 	struct acrn_vm *vm = vdev->vpci->vm;
 
 	ret = unassign_iommu_device(vm->iommu, (uint8_t)vdev->pdev.bdf.bits.b,
@@ -97,7 +97,7 @@ static int vdev_pt_deinit(struct pci_vdev *vdev)
 	return ret;
 }
 
-static int vdev_pt_cfgread(struct pci_vdev *vdev, uint32_t offset,
+static int32_t vdev_pt_cfgread(struct pci_vdev *vdev, uint32_t offset,
 	uint32_t bytes, uint32_t *val)
 {
 	/* Assumption: access needed to be aligned on 1/2/4 bytes */
@@ -176,7 +176,7 @@ static void vdev_pt_cfgwrite_bar(struct pci_vdev *vdev, uint32_t offset,
 	pci_vdev_write_cfg_u32(vdev, offset, new_bar);
 }
 
-static int vdev_pt_cfgwrite(struct pci_vdev *vdev, uint32_t offset,
+static int32_t vdev_pt_cfgwrite(struct pci_vdev *vdev, uint32_t offset,
 	uint32_t bytes, uint32_t val)
 {
 	/* Assumption: access needed to be aligned on 1/2/4 bytes */
diff --git a/hypervisor/dm/vpic.c b/hypervisor/dm/vpic.c
index 039a510e9..a437f6a47 100644
--- a/hypervisor/dm/vpic.c
+++ b/hypervisor/dm/vpic.c
@@ -241,7 +241,7 @@ static int32_t vpic_icw1(const struct acrn_vpic *vpic, struct i8259_reg_state *i
 	return ret;
 }
 
-static int vpic_icw2(const struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint8_t val)
+static int32_t vpic_icw2(const struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint8_t val)
 {
 	dev_dbg(ACRN_DBG_PIC, "vm 0x%x: i8259 icw2 0x%x\n",
 		vpic->vm, val);
@@ -253,7 +253,7 @@ static int vpic_icw2(const struct acrn_vpic *vpic, struct i8259_reg_state *i8259
 	return 0;
 }
 
-static int vpic_icw3(const struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint8_t val)
+static int32_t vpic_icw3(const struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint8_t val)
 {
 	dev_dbg(ACRN_DBG_PIC, "vm 0x%x: i8259 icw3 0x%x\n",
 		vpic->vm, val);
@@ -297,7 +297,7 @@ static int32_t vpic_icw4(const struct acrn_vpic *vpic, struct i8259_reg_state *i
 	return ret;
 }
 
-static int vpic_ocw1(const struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint8_t val)
+static int32_t vpic_ocw1(const struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint8_t val)
 {
 	uint8_t pin, i, bit;
 	uint8_t old = i8259->mask;
@@ -337,7 +337,7 @@ static int vpic_ocw1(const struct acrn_vpic *vpic, struct i8259_reg_state *i8259
 	return 0;
 }
 
-static int vpic_ocw2(struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint8_t val)
+static int32_t vpic_ocw2(struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint8_t val)
 {
 	dev_dbg(ACRN_DBG_PIC, "vm 0x%x: i8259 ocw2 0x%x\n",
 		vpic->vm, val);
@@ -379,7 +379,7 @@ static int vpic_ocw2(struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint
 	return 0;
 }
 
-static int vpic_ocw3(struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint8_t val)
+static int32_t vpic_ocw3(struct acrn_vpic *vpic, struct i8259_reg_state *i8259, uint8_t val)
 {
 	dev_dbg(ACRN_DBG_PIC, "vm 0x%x: i8259 ocw3 0x%x\n",
 		vpic->vm, val);
@@ -616,7 +616,7 @@ void vpic_intr_accepted(struct acrn_vm *vm, uint32_t vector)
 	spinlock_release(&(vpic->lock));
 }
 
-static int vpic_read(struct acrn_vpic *vpic, struct i8259_reg_state *i8259,
+static int32_t vpic_read(struct acrn_vpic *vpic, struct i8259_reg_state *i8259,
 		uint16_t port, uint32_t *eax)
 {
 	uint8_t pin;
@@ -652,10 +652,10 @@ static int vpic_read(struct acrn_vpic *vpic, struct i8259_reg_state *i8259,
 	return 0;
 }
 
-static int vpic_write(struct acrn_vpic *vpic, struct i8259_reg_state *i8259,
+static int32_t vpic_write(struct acrn_vpic *vpic, struct i8259_reg_state *i8259,
 		uint16_t port, uint32_t *eax)
 {
-	int error;
+	int32_t error;
 	uint8_t val;
 
 	error = 0;
diff --git a/hypervisor/dm/vrtc.c b/hypervisor/dm/vrtc.c
index 195835e23..862364d01 100644
--- a/hypervisor/dm/vrtc.c
+++ b/hypervisor/dm/vrtc.c
@@ -28,7 +28,7 @@ static bool cmos_update_in_progress(void)
 static uint8_t cmos_get_reg_val(uint8_t addr)
 {
 	uint8_t reg;
-	int tries = 2000U;
+	int32_t tries = 2000U;
 
 	spinlock_obtain(&cmos_lock);
 
diff --git a/hypervisor/include/arch/x86/assign.h b/hypervisor/include/arch/x86/assign.h
index 3ddb37013..ec15531d4 100644
--- a/hypervisor/include/arch/x86/assign.h
+++ b/hypervisor/include/arch/x86/assign.h
@@ -59,7 +59,7 @@ void ptirq_intx_ack(struct acrn_vm *vm, uint8_t virt_pin, enum ptirq_vpin_source
  * @pre info != NULL
  *
  */
-int ptirq_msix_remap(struct acrn_vm *vm, uint16_t virt_bdf, uint16_t entry_nr, struct ptirq_msi_info *info);
+int32_t ptirq_msix_remap(struct acrn_vm *vm, uint16_t virt_bdf, uint16_t entry_nr, struct ptirq_msi_info *info);
 
 
 /**
@@ -81,7 +81,7 @@ int ptirq_msix_remap(struct acrn_vm *vm, uint16_t virt_bdf, uint16_t entry_nr, s
  * @pre vm != NULL
  *
  */
-int ptirq_intx_pin_remap(struct acrn_vm *vm, uint8_t virt_pin, enum ptirq_vpin_source vpin_src);
+int32_t ptirq_intx_pin_remap(struct acrn_vm *vm, uint8_t virt_pin, enum ptirq_vpin_source vpin_src);
 
 /**
  * @brief Add an interrupt remapping entry for INTx as pre-hold mapping.
@@ -103,7 +103,7 @@ int ptirq_intx_pin_remap(struct acrn_vm *vm, uint8_t virt_pin, enum ptirq_vpin_s
  * @pre vm != NULL
  *
  */
-int ptirq_add_intx_remapping(struct acrn_vm *vm, uint8_t virt_pin, uint8_t phys_pin, bool pic_pin);
+int32_t ptirq_add_intx_remapping(struct acrn_vm *vm, uint8_t virt_pin, uint8_t phys_pin, bool pic_pin);
 
 /**
  * @brief Remove an interrupt remapping entry for INTx.
@@ -140,7 +140,7 @@ void ptirq_remove_intx_remapping(struct acrn_vm *vm, uint8_t virt_pin, bool pic_
  * @pre vm != NULL
  *
  */
-int ptirq_add_msix_remapping(struct acrn_vm *vm, uint16_t virt_bdf, uint16_t phys_bdf, uint32_t vector_count);
+int32_t ptirq_add_msix_remapping(struct acrn_vm *vm, uint16_t virt_bdf, uint16_t phys_bdf, uint32_t vector_count);
 
 /**
  * @brief Remove interrupt remapping entry/entries for MSI/MSI-x.
diff --git a/hypervisor/include/arch/x86/cpu.h b/hypervisor/include/arch/x86/cpu.h
index 179764e34..dec9c72c3 100644
--- a/hypervisor/include/arch/x86/cpu.h
+++ b/hypervisor/include/arch/x86/cpu.h
@@ -211,7 +211,7 @@ extern uint8_t		ld_bss_end;
 /* In trampoline range, hold the jump target which trampline will jump to */
 extern uint64_t               main_entry[1];
 
-extern int ibrs_type;
+extern int32_t ibrs_type;
 extern spinlock_t trampoline_spinlock;
 
 /*
@@ -526,7 +526,7 @@ msr_write(uint32_t reg_num, uint64_t value64)
 }
 
 static inline void
-write_xcr(int reg, uint64_t val)
+write_xcr(int32_t reg, uint64_t val)
 {
 	uint32_t low, high;
 
diff --git a/hypervisor/include/arch/x86/cpuid.h b/hypervisor/include/arch/x86/cpuid.h
index 7bd70749f..5034ca0df 100644
--- a/hypervisor/include/arch/x86/cpuid.h
+++ b/hypervisor/include/arch/x86/cpuid.h
@@ -135,7 +135,7 @@ static inline void cpuid_subleaf(uint32_t leaf, uint32_t subleaf,
 	asm_cpuid(eax, ebx, ecx, edx);
 }
 
-int set_vcpuid_entries(struct acrn_vm *vm);
+int32_t set_vcpuid_entries(struct acrn_vm *vm);
 void guest_cpuid(struct acrn_vcpu *vcpu,
 			uint32_t *eax, uint32_t *ebx,
 			uint32_t *ecx, uint32_t *edx);
diff --git a/hypervisor/include/arch/x86/guest/guest.h b/hypervisor/include/arch/x86/guest/guest.h
index 4da6ff210..0f9ad8714 100644
--- a/hypervisor/include/arch/x86/guest/guest.h
+++ b/hypervisor/include/arch/x86/guest/guest.h
@@ -70,7 +70,8 @@
 #define LDTR_AR                         (0x0082U) /* LDT, type must be 2, refer to SDM Vol3 26.3.1.2 */
 #define TR_AR                           (0x008bU) /* TSS (busy), refer to SDM Vol3 26.3.1.2 */
 
-int prepare_vm0_memmap(struct acrn_vm *vm);
+int32_t prepare_vm0_memmap(struct acrn_vm *vm);
+
 /* Definition for a mem map lookup */
 struct vm_lu_mem_map {
 	struct list_head list;                 /* EPT mem map lookup list*/
@@ -93,22 +94,22 @@ enum vm_paging_mode {
  */
 uint64_t vcpumask2pcpumask(struct acrn_vm *vm, uint64_t vdmask);
 
-int gva2gpa(struct acrn_vcpu *vcpu, uint64_t gva, uint64_t *gpa, uint32_t *err_code);
+int32_t gva2gpa(struct acrn_vcpu *vcpu, uint64_t gva, uint64_t *gpa, uint32_t *err_code);
 
 enum vm_paging_mode get_vcpu_paging_mode(struct acrn_vcpu *vcpu);
 
-int rdmsr_vmexit_handler(struct acrn_vcpu *vcpu);
-int wrmsr_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t rdmsr_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t wrmsr_vmexit_handler(struct acrn_vcpu *vcpu);
 void init_msr_emulation(struct acrn_vcpu *vcpu);
 
 uint32_t vmsr_get_guest_msr_index(uint32_t msr);
 
 struct run_context;
-int vmx_vmrun(struct run_context *context, int ops, int ibrs);
+int32_t vmx_vmrun(struct run_context *context, int32_t ops, int32_t ibrs);
 
-int general_sw_loader(struct acrn_vm *vm);
+int32_t general_sw_loader(struct acrn_vm *vm);
 
-typedef int (*vm_sw_loader_t)(struct acrn_vm *vm);
+typedef int32_t (*vm_sw_loader_t)(struct acrn_vm *vm);
 extern vm_sw_loader_t vm_sw_loader;
 /**
  * @brief Data transfering between hypervisor and VM
@@ -134,7 +135,7 @@ extern vm_sw_loader_t vm_sw_loader;
  *   continuous
  * @pre Pointer vm is non-NULL
  */
-int copy_from_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size);
+int32_t copy_from_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size);
 /**
  * @brief Copy data from HV address space to VM GPA space
  *
@@ -153,7 +154,7 @@ int copy_from_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size);
  *   continuous
  * @pre Pointer vm is non-NULL
  */
-int copy_to_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size);
+int32_t copy_to_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size);
 /**
  * @brief Copy data from VM GVA space to HV address space
  *
@@ -167,7 +168,7 @@ int copy_to_gpa(struct acrn_vm *vm, void *h_ptr, uint64_t gpa, uint32_t size);
  * @param[out] err_code The page fault flags
  * @param[out] fault_addr The GVA address that causes a page fault
  */
-int copy_from_gva(struct acrn_vcpu *vcpu, void *h_ptr, uint64_t gva,
+int32_t copy_from_gva(struct acrn_vcpu *vcpu, void *h_ptr, uint64_t gva,
 	uint32_t size, uint32_t *err_code, uint64_t *fault_addr);
 /**
  * @brief Copy data from HV address space to VM GVA space
@@ -182,7 +183,7 @@ int copy_from_gva(struct acrn_vcpu *vcpu, void *h_ptr, uint64_t gva,
  * @param[out] err_code The page fault flags
  * @param[out] fault_addr The GVA address that causes a page fault
  */
-int copy_to_gva(struct acrn_vcpu *vcpu, void *h_ptr, uint64_t gva,
+int32_t copy_to_gva(struct acrn_vcpu *vcpu, void *h_ptr, uint64_t gva,
 	uint32_t size, uint32_t *err_code, uint64_t *fault_addr);
 /**
  * @}
diff --git a/hypervisor/include/arch/x86/guest/guest_pm.h b/hypervisor/include/arch/x86/guest/guest_pm.h
index c4385dff8..0730620d1 100644
--- a/hypervisor/include/arch/x86/guest/guest_pm.h
+++ b/hypervisor/include/arch/x86/guest/guest_pm.h
@@ -8,8 +8,8 @@
 #define GUEST_PM_H
 
 void vm_setup_cpu_state(struct acrn_vm *vm);
-int vm_load_pm_s_state(struct acrn_vm *vm);
-int validate_pstate(const struct acrn_vm *vm, uint64_t perf_ctl);
+int32_t vm_load_pm_s_state(struct acrn_vm *vm);
+int32_t validate_pstate(const struct acrn_vm *vm, uint64_t perf_ctl);
 void register_pm1ab_handler(struct acrn_vm *vm);
 
 #endif /* PM_H */
diff --git a/hypervisor/include/arch/x86/guest/mptable.h b/hypervisor/include/arch/x86/guest/mptable.h
index 6febde547..ec0065277 100644
--- a/hypervisor/include/arch/x86/guest/mptable.h
+++ b/hypervisor/include/arch/x86/guest/mptable.h
@@ -26,6 +26,6 @@ struct mptable_info;
 extern struct mptable_info mptable_vm1;
 extern struct mptable_info mptable_vm2;
 
-int mptable_build(struct acrn_vm *vm);
+int32_t mptable_build(struct acrn_vm *vm);
 
 #endif /* MPTABLE_H */
diff --git a/hypervisor/include/arch/x86/guest/vcpu.h b/hypervisor/include/arch/x86/guest/vcpu.h
index 03352883a..e2f3e717e 100644
--- a/hypervisor/include/arch/x86/guest/vcpu.h
+++ b/hypervisor/include/arch/x86/guest/vcpu.h
@@ -204,7 +204,7 @@ struct acrn_vcpu_arch {
 	uint8_t vmcs[PAGE_SIZE];
 	/* per vcpu lapic */
 	struct acrn_vlapic vlapic;
-	int cur_context;
+	int32_t cur_context;
 	struct cpu_context contexts[NR_WORLD];
 
 	/* common MSRs, world_msrs[] is a subset of it */
@@ -551,7 +551,7 @@ struct acrn_vcpu* get_ever_run_vcpu(uint16_t pcpu_id);
  *
  * @retval 0 vcpu created successfully, other values failed.
  */
-int create_vcpu(uint16_t pcpu_id, struct acrn_vm *vm, struct acrn_vcpu **rtn_vcpu_handle);
+int32_t create_vcpu(uint16_t pcpu_id, struct acrn_vm *vm, struct acrn_vcpu **rtn_vcpu_handle);
 
 /**
  * @brief run into non-root mode based on vcpu setting
@@ -564,9 +564,9 @@ int create_vcpu(uint16_t pcpu_id, struct acrn_vm *vm, struct acrn_vcpu **rtn_vcp
  *
  * @retval 0 vcpu run successfully, other values failed.
  */
-int run_vcpu(struct acrn_vcpu *vcpu);
+int32_t run_vcpu(struct acrn_vcpu *vcpu);
 
-int shutdown_vcpu(struct acrn_vcpu *vcpu);
+int32_t shutdown_vcpu(struct acrn_vcpu *vcpu);
 
 /**
  * @brief unmap the vcpu with pcpu and free its vlapic
@@ -623,7 +623,7 @@ void schedule_vcpu(struct acrn_vcpu *vcpu);
  * @param[inout] vm pointer to vm data structure
  * @param[in] pcpu_id which the vcpu will be mapped
  */
-int prepare_vcpu(struct acrn_vm *vm, uint16_t pcpu_id);
+int32_t prepare_vcpu(struct acrn_vm *vm, uint16_t pcpu_id);
 
 void request_vcpu_pre_work(struct acrn_vcpu *vcpu, uint16_t pre_work_id);
 
diff --git a/hypervisor/include/arch/x86/guest/vioapic.h b/hypervisor/include/arch/x86/guest/vioapic.h
index 404d09d6a..08b823ef3 100644
--- a/hypervisor/include/arch/x86/guest/vioapic.h
+++ b/hypervisor/include/arch/x86/guest/vioapic.h
@@ -104,7 +104,7 @@ void	vioapic_update_tmr(struct acrn_vcpu *vcpu);
 uint32_t	vioapic_pincount(const struct acrn_vm *vm);
 void	vioapic_process_eoi(struct acrn_vm *vm, uint32_t vector);
 void	vioapic_get_rte(struct acrn_vm *vm, uint32_t pin, union ioapic_rte *rte);
-int		vioapic_mmio_access_handler(struct io_request *io_req, void *handler_private_data);
+int32_t	vioapic_mmio_access_handler(struct io_request *io_req, void *handler_private_data);
 
 /**
  * @}
diff --git a/hypervisor/include/arch/x86/guest/vlapic.h b/hypervisor/include/arch/x86/guest/vlapic.h
index ee1a47d08..3a96ef07f 100644
--- a/hypervisor/include/arch/x86/guest/vlapic.h
+++ b/hypervisor/include/arch/x86/guest/vlapic.h
@@ -75,7 +75,7 @@ struct acrn_vlapic {
 	struct acrn_vcpu		*vcpu;
 
 	uint32_t		esr_pending;
-	int			esr_firing;
+	int32_t			esr_firing;
 
 	struct vlapic_timer	vtimer;
 
@@ -134,7 +134,7 @@ uint64_t vlapic_get_cr8(const struct acrn_vlapic *vlapic);
  * @remark The vector does not automatically transition to the ISR as a
  *	   result of calling this function.
  */
-int vlapic_pending_intr(const struct acrn_vlapic *vlapic, uint32_t *vecptr);
+int32_t vlapic_pending_intr(const struct acrn_vlapic *vlapic, uint32_t *vecptr);
 
 /**
  * @brief Accept virtual interrupt.
@@ -181,8 +181,8 @@ void vlapic_post_intr(uint16_t dest_pcpu_id);
  */
 uint64_t apicv_get_pir_desc_paddr(struct acrn_vcpu *vcpu);
 
-int vlapic_rdmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t *rval);
-int vlapic_wrmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t wval);
+int32_t vlapic_rdmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t *rval);
+int32_t vlapic_wrmsr(struct acrn_vcpu *vcpu, uint32_t msr, uint64_t wval);
 
 /*
  * Signals to the LAPIC that an interrupt at 'vector' needs to be generated
@@ -265,7 +265,7 @@ void vlapic_set_tmr_one_vec(struct acrn_vlapic *vlapic, uint32_t delmode,
 
 void vlapic_apicv_batch_set_tmr(struct acrn_vlapic *vlapic);
 uint32_t vlapic_get_apicid(struct acrn_vlapic *vlapic);
-int vlapic_create(struct acrn_vcpu *vcpu);
+int32_t vlapic_create(struct acrn_vcpu *vcpu);
 /*
  *  @pre vcpu != NULL
  */
@@ -277,10 +277,10 @@ bool vlapic_enabled(const struct acrn_vlapic *vlapic);
 uint64_t vlapic_apicv_get_apic_access_addr(void);
 uint64_t vlapic_apicv_get_apic_page_addr(struct acrn_vlapic *vlapic);
 void vlapic_apicv_inject_pir(struct acrn_vlapic *vlapic);
-int apic_access_vmexit_handler(struct acrn_vcpu *vcpu);
-int apic_write_vmexit_handler(struct acrn_vcpu *vcpu);
-int veoi_vmexit_handler(struct acrn_vcpu *vcpu);
-int tpr_below_threshold_vmexit_handler(__unused struct acrn_vcpu *vcpu);
+int32_t apic_access_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t apic_write_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t veoi_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t tpr_below_threshold_vmexit_handler(__unused struct acrn_vcpu *vcpu);
 void calcvdest(struct acrn_vm *vm, uint64_t *dmask, uint32_t dest, bool phys);
 
 /**
diff --git a/hypervisor/include/arch/x86/guest/vm.h b/hypervisor/include/arch/x86/guest/vm.h
index 367d0cfef..ebccbd30d 100644
--- a/hypervisor/include/arch/x86/guest/vm.h
+++ b/hypervisor/include/arch/x86/guest/vm.h
@@ -48,7 +48,7 @@ struct sw_kernel_info {
 };
 
 struct vm_sw_info {
-	int kernel_type;	/* Guest kernel type */
+	int32_t kernel_type;	/* Guest kernel type */
 	/* Kernel information (common for all guest types) */
 	struct sw_kernel_info kernel_info;
 	/* Additional information specific to Linux guests */
@@ -164,7 +164,7 @@ struct acrn_vm {
 
 #ifdef CONFIG_PARTITION_MODE
 struct vpci_vdev_array {
-	int num_pci_vdev;
+	int32_t num_pci_vdev;
 	struct pci_vdev vpci_vdev_list[];
 };
 #endif
@@ -257,14 +257,14 @@ vm_ioapic(struct acrn_vm *vm)
 	return (struct acrn_vioapic *)&(vm->arch_vm.vioapic);
 }
 
-int shutdown_vm(struct acrn_vm *vm);
+int32_t shutdown_vm(struct acrn_vm *vm);
 void pause_vm(struct acrn_vm *vm);
 void resume_vm(struct acrn_vm *vm);
 void resume_vm_from_s3(struct acrn_vm *vm, uint32_t wakeup_vec);
-int start_vm(struct acrn_vm *vm);
-int reset_vm(struct acrn_vm *vm);
-int create_vm(struct vm_description *vm_desc, struct acrn_vm **rtn_vm);
-int prepare_vm(uint16_t pcpu_id);
+int32_t start_vm(struct acrn_vm *vm);
+int32_t reset_vm(struct acrn_vm *vm);
+int32_t create_vm(struct vm_description *vm_desc, struct acrn_vm **rtn_vm);
+int32_t prepare_vm(uint16_t pcpu_id);
 
 #ifdef CONFIG_PARTITION_MODE
 const struct vm_description_array *get_vm_desc_base(void);
@@ -274,7 +274,7 @@ struct acrn_vm *get_vm_from_vmid(uint16_t vm_id);
 
 #ifdef CONFIG_PARTITION_MODE
 struct vm_description_array {
-	int                     num_vm_desc;
+	int32_t                     num_vm_desc;
 	struct vm_description   vm_desc_array[];
 };
 
diff --git a/hypervisor/include/arch/x86/ioreq.h b/hypervisor/include/arch/x86/ioreq.h
index 8912c41af..463e30eb0 100644
--- a/hypervisor/include/arch/x86/ioreq.h
+++ b/hypervisor/include/arch/x86/ioreq.h
@@ -115,7 +115,7 @@ struct vm_io_handler_desc {
 
 /* Typedef for MMIO handler and range check routine */
 struct mmio_request;
-typedef int (*hv_mem_io_handler_t)(struct io_request *io_req, void *handler_private_data);
+typedef int32_t (*hv_mem_io_handler_t)(struct io_request *io_req, void *handler_private_data);
 
 /**
  * @brief Structure for MMIO handler node
@@ -223,7 +223,7 @@ void   register_io_emulation_handler(struct acrn_vm *vm, uint32_t pio_idx,
  * @retval 0 Registration succeeds
  * @retval -EINVAL \p read_write is NULL, \p end is not larger than \p start or \p vm has been launched
  */
-int register_mmio_emulation_handler(struct acrn_vm *vm,
+int32_t register_mmio_emulation_handler(struct acrn_vm *vm,
 	hv_mem_io_handler_t read_write, uint64_t start,
 	uint64_t end, void *handler_private_data);
 
diff --git a/hypervisor/include/arch/x86/irq.h b/hypervisor/include/arch/x86/irq.h
index 5bc541355..e47bae980 100644
--- a/hypervisor/include/arch/x86/irq.h
+++ b/hypervisor/include/arch/x86/irq.h
@@ -137,7 +137,7 @@ uint32_t irq_to_vector(uint32_t irq);
  *
  * @pre vcpu != NULL
  */
-int vcpu_queue_exception(struct acrn_vcpu *vcpu, uint32_t vector, uint32_t err_code);
+int32_t vcpu_queue_exception(struct acrn_vcpu *vcpu, uint32_t vector, uint32_t err_code);
 
 /**
  * @brief Inject external interrupt to guest.
@@ -223,10 +223,10 @@ void vcpu_make_request(struct acrn_vcpu *vcpu, uint16_t eventid);
 /*
  * @pre vcpu != NULL
  */
-int exception_vmexit_handler(struct acrn_vcpu *vcpu);
-int interrupt_window_vmexit_handler(struct acrn_vcpu *vcpu);
-int external_interrupt_vmexit_handler(struct acrn_vcpu *vcpu);
-int acrn_handle_pending_request(struct acrn_vcpu *vcpu);
+int32_t exception_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t interrupt_window_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t external_interrupt_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t acrn_handle_pending_request(struct acrn_vcpu *vcpu);
 
 /**
  * @brief Initialize the interrupt
diff --git a/hypervisor/include/arch/x86/mmu.h b/hypervisor/include/arch/x86/mmu.h
index ab4df43c4..627925e55 100644
--- a/hypervisor/include/arch/x86/mmu.h
+++ b/hypervisor/include/arch/x86/mmu.h
@@ -122,7 +122,7 @@ void mmu_modify_or_del(uint64_t *pml4_page, uint64_t vaddr_base, uint64_t size,
  * @retval 0 on success
  * @retval -ENODEV Don't support EPT or VPID capability
  */
-int check_vmx_mmu_cap(void);
+int32_t check_vmx_mmu_cap(void);
 /**
  * @brief VPID allocation
  *
@@ -293,7 +293,7 @@ void ept_mr_del(struct acrn_vm *vm, uint64_t *pml4_page, uint64_t gpa,
  * @retval -EINVAL fail to handle the EPT violation
  * @retval 0 Success to handle the EPT violation
  */
-int ept_violation_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t ept_violation_vmexit_handler(struct acrn_vcpu *vcpu);
 /**
  * @brief EPT misconfiguration handling
  *
@@ -302,7 +302,7 @@ int ept_violation_vmexit_handler(struct acrn_vcpu *vcpu);
  * @retval -EINVAL fail to handle the EPT misconfig
  * @retval 0 Success to handle the EPT misconfig
  */
-int ept_misconfig_vmexit_handler(__unused struct acrn_vcpu *vcpu);
+int32_t ept_misconfig_vmexit_handler(__unused struct acrn_vcpu *vcpu);
 
 /**
  * @}
diff --git a/hypervisor/include/arch/x86/multiboot.h b/hypervisor/include/arch/x86/multiboot.h
index e20656a0a..4ec19e945 100644
--- a/hypervisor/include/arch/x86/multiboot.h
+++ b/hypervisor/include/arch/x86/multiboot.h
@@ -78,8 +78,8 @@ struct multiboot_module {
 	uint32_t	mm_reserved;
 };
 
-int parse_hv_cmdline(void);
-int init_vm_boot_info(struct acrn_vm *vm);
+int32_t parse_hv_cmdline(void);
+int32_t init_vm_boot_info(struct acrn_vm *vm);
 
 /* boot_regs store the multiboot header address */
 extern uint32_t boot_regs[2];
diff --git a/hypervisor/include/arch/x86/timer.h b/hypervisor/include/arch/x86/timer.h
index c28cd5853..e90179776 100644
--- a/hypervisor/include/arch/x86/timer.h
+++ b/hypervisor/include/arch/x86/timer.h
@@ -62,7 +62,7 @@ struct hv_timer {
  */
 static inline void initialize_timer(struct hv_timer *timer,
 				timer_handle_t func, void *priv_data,
-				uint64_t fire_tsc, int mode, uint64_t period_in_cycle)
+				uint64_t fire_tsc, int32_t mode, uint64_t period_in_cycle)
 {
 	if (timer != NULL) {
 		timer->func = func;
@@ -96,7 +96,7 @@ static inline bool timer_expired(const struct hv_timer *timer)
  *
  * @remark Don't call it in the timer callback function or interrupt content.
  */
-int add_timer(struct hv_timer *timer);
+int32_t add_timer(struct hv_timer *timer);
 
 /**
  * @brief Delete a timer.
diff --git a/hypervisor/include/arch/x86/trusty.h b/hypervisor/include/arch/x86/trusty.h
index 7282cc5ba..271c0e86f 100644
--- a/hypervisor/include/arch/x86/trusty.h
+++ b/hypervisor/include/arch/x86/trusty.h
@@ -126,7 +126,7 @@ struct trusty_startup_param {
 	uint8_t padding[4];
 };
 
-void switch_world(struct acrn_vcpu *vcpu, int next_world);
+void switch_world(struct acrn_vcpu *vcpu, int32_t next_world);
 bool initialize_trusty(struct acrn_vcpu *vcpu, uint64_t param);
 void destroy_secure_world(struct acrn_vm *vm, bool need_clr_mem);
 void save_sworld_context(struct acrn_vcpu *vcpu);
diff --git a/hypervisor/include/arch/x86/vmexit.h b/hypervisor/include/arch/x86/vmexit.h
index 29b2cde72..bb409567a 100644
--- a/hypervisor/include/arch/x86/vmexit.h
+++ b/hypervisor/include/arch/x86/vmexit.h
@@ -8,14 +8,14 @@
 #define VMEXIT_H_
 
 struct vm_exit_dispatch {
-	int (*handler)(struct acrn_vcpu *);
+	int32_t (*handler)(struct acrn_vcpu *);
 	uint32_t need_exit_qualification;
 };
 
-int vmexit_handler(struct acrn_vcpu *vcpu);
-int vmcall_vmexit_handler(struct acrn_vcpu *vcpu);
-int cpuid_vmexit_handler(struct acrn_vcpu *vcpu);
-int cr_access_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t vmcall_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t cpuid_vmexit_handler(struct acrn_vcpu *vcpu);
+int32_t cr_access_vmexit_handler(struct acrn_vcpu *vcpu);
 extern void vm_exit(void);
 static inline uint64_t
 vm_exit_qualification_bit_mask(uint64_t exit_qual, uint32_t msb, uint32_t lsb)
diff --git a/hypervisor/include/arch/x86/vmx.h b/hypervisor/include/arch/x86/vmx.h
index b0a5e29de..00b6fa1ba 100644
--- a/hypervisor/include/arch/x86/vmx.h
+++ b/hypervisor/include/arch/x86/vmx.h
@@ -459,7 +459,7 @@ void exec_vmclear(void *addr);
 void exec_vmptrld(void *addr);
 
 uint64_t vmx_rdmsr_pat(const struct acrn_vcpu *vcpu);
-int vmx_wrmsr_pat(struct acrn_vcpu *vcpu, uint64_t value);
+int32_t vmx_wrmsr_pat(struct acrn_vcpu *vcpu, uint64_t value);
 
 void vmx_write_cr0(struct acrn_vcpu *vcpu, uint64_t cr0);
 void vmx_write_cr4(struct acrn_vcpu *vcpu, uint64_t cr4);
diff --git a/hypervisor/include/arch/x86/vtd.h b/hypervisor/include/arch/x86/vtd.h
index 02f704c19..7efe001a8 100644
--- a/hypervisor/include/arch/x86/vtd.h
+++ b/hypervisor/include/arch/x86/vtd.h
@@ -502,7 +502,7 @@ struct iommu_domain;
  * @pre domain != NULL
  *
  */
-int assign_iommu_device(struct iommu_domain *domain, uint8_t bus, uint8_t devfun);
+int32_t assign_iommu_device(struct iommu_domain *domain, uint8_t bus, uint8_t devfun);
 
 /**
  * @brief Unassign a device specified by bus & devfun from a iommu domain .
@@ -519,7 +519,7 @@ int assign_iommu_device(struct iommu_domain *domain, uint8_t bus, uint8_t devfun
  * @pre domain != NULL
  *
  */
-int unassign_iommu_device(const struct iommu_domain *domain, uint8_t bus, uint8_t devfun);
+int32_t unassign_iommu_device(const struct iommu_domain *domain, uint8_t bus, uint8_t devfun);
 
 /**
  * @brief Create a iommu domain for a VM specified by vm_id.
@@ -596,7 +596,7 @@ void resume_iommu(void);
  * @retval <0 on failure
  *
  */
-int init_iommu(void);
+int32_t init_iommu(void);
 
 /**
  * @brief Init VM0 domain of iommu.
diff --git a/hypervisor/include/common/ptdev.h b/hypervisor/include/common/ptdev.h
index 91d4eb966..5fa2095d4 100644
--- a/hypervisor/include/common/ptdev.h
+++ b/hypervisor/include/common/ptdev.h
@@ -44,7 +44,7 @@ struct ptirq_msi_info {
 	uint32_t vmsi_data; /* virt msi_data */
 	uint64_t pmsi_addr; /* phys msi_addr */
 	uint32_t pmsi_data; /* phys msi_data */
-	int is_msix;	/* 0-MSI, 1-MSIX */
+	int32_t is_msix;	/* 0-MSI, 1-MSIX */
 };
 
 /* entry per each allocated irq/vector
diff --git a/hypervisor/include/common/schedule.h b/hypervisor/include/common/schedule.h
index 44ae67978..990b838ab 100644
--- a/hypervisor/include/common/schedule.h
+++ b/hypervisor/include/common/schedule.h
@@ -32,9 +32,9 @@ void remove_vcpu_from_runqueue(struct acrn_vcpu *vcpu);
 void default_idle(void);
 
 void make_reschedule_request(const struct acrn_vcpu *vcpu);
-int need_reschedule(uint16_t pcpu_id);
+int32_t need_reschedule(uint16_t pcpu_id);
 void make_pcpu_offline(uint16_t pcpu_id);
-int need_offline(uint16_t pcpu_id);
+int32_t need_offline(uint16_t pcpu_id);
 
 void schedule(void);
 
diff --git a/hypervisor/include/debug/sbuf.h b/hypervisor/include/debug/sbuf.h
index c5d74fe15..393e39499 100644
--- a/hypervisor/include/debug/sbuf.h
+++ b/hypervisor/include/debug/sbuf.h
@@ -64,7 +64,7 @@ struct shared_buf {
  *@pre data != NULL
  */
 uint32_t sbuf_put(struct shared_buf *sbuf, uint8_t *data);
-int sbuf_share_setup(uint16_t pcpu_id, uint32_t sbuf_id, uint64_t *hva);
+int32_t sbuf_share_setup(uint16_t pcpu_id, uint32_t sbuf_id, uint64_t *hva);
 uint32_t sbuf_next_ptr(uint32_t pos, uint32_t span, uint32_t scope);
 
 #endif /* SHARED_BUFFER_H */
diff --git a/hypervisor/include/dm/vpci.h b/hypervisor/include/dm/vpci.h
index 0028df558..edebcfdb5 100644
--- a/hypervisor/include/dm/vpci.h
+++ b/hypervisor/include/dm/vpci.h
@@ -38,7 +38,7 @@ struct pci_vdev_ops {
 
 	int32_t (*deinit)(struct pci_vdev *vdev);
 
-	int (*cfgwrite)(struct pci_vdev *vdev, uint32_t offset,
+	int32_t (*cfgwrite)(struct pci_vdev *vdev, uint32_t offset,
 		uint32_t bytes, uint32_t val);
 
 	int32_t (*cfgread)(struct pci_vdev *vdev, uint32_t offset,
diff --git a/hypervisor/include/lib/crypto/crypto_api.h b/hypervisor/include/lib/crypto/crypto_api.h
index f052e6f2f..eb9dfe473 100644
--- a/hypervisor/include/lib/crypto/crypto_api.h
+++ b/hypervisor/include/lib/crypto/crypto_api.h
@@ -32,9 +32,9 @@
  *                     optional. Ignored if info == NULL or a zero-length string
  * @param   info_len:  The length of the info, ignored if info is NULL
  *
- * @return int 1 - Success  0 - Failure
+ * @return int32_t 1 - Success  0 - Failure
  */
-int hkdf_sha256(uint8_t *out_key, size_t out_len,
+int32_t hkdf_sha256(uint8_t *out_key, size_t out_len,
 		const uint8_t *secret, size_t secret_len,
 		const uint8_t *salt, size_t salt_len,
 		const uint8_t *info, size_t info_len);
@@ -55,9 +55,9 @@ int hkdf_sha256(uint8_t *out_key, size_t out_len,
  * @param   salt        The buffer holding the input data
  * @param   salt_len    The length of the input data
  *
- * @return int 1 - Success  0 - Failure
+ * @return int32_t 1 - Success  0 - Failure
  */
-int hmac_sha256(uint8_t *out_key,
+int32_t hmac_sha256(uint8_t *out_key,
 		const uint8_t *secret, size_t secret_len,
 		const uint8_t *salt, size_t salt_len);
 
diff --git a/hypervisor/include/lib/rtl.h b/hypervisor/include/lib/rtl.h
index c79a6d31b..6ba21cc5e 100644
--- a/hypervisor/include/lib/rtl.h
+++ b/hypervisor/include/lib/rtl.h
@@ -21,16 +21,16 @@ union u_qword {
 
 /* Function prototypes */
 void udelay(uint32_t us);
-void *memchr(const void *void_s, int c, size_t n);
-int strcmp(const char *s1_arg, const char *s2_arg);
-int strncmp(const char *s1_arg, const char *s2_arg, size_t n_arg);
+void *memchr(const void *void_s, int32_t c, size_t n);
+int32_t strcmp(const char *s1_arg, const char *s2_arg);
+int32_t strncmp(const char *s1_arg, const char *s2_arg, size_t n_arg);
 char *strcpy_s(char *d_arg, size_t dmax, const char *s_arg);
 char *strncpy_s(char *d_arg, size_t dmax, const char *s_arg, size_t slen_arg);
 char *strchr(char *s_arg, char ch);
 size_t strnlen_s(const char *str_arg, size_t maxlen_arg);
 void *memset(void *base, uint8_t v, size_t n);
 void *memcpy_s(void *d, size_t dmax, const void *s, size_t slen_arg);
-int atoi(const char *str);
+int32_t atoi(const char *str);
 long strtol_deci(const char *nptr);
 uint64_t strtoul_hex(const char *nptr);
 char *strstr_s(const char *str1, size_t maxlen1,
diff --git a/hypervisor/lib/crypto/crypto_api.c b/hypervisor/lib/crypto/crypto_api.c
index 03c0dd8e7..0053ce40d 100644
--- a/hypervisor/lib/crypto/crypto_api.c
+++ b/hypervisor/lib/crypto/crypto_api.c
@@ -8,7 +8,7 @@
 #include "mbedtls/hkdf.h"
 #include "mbedtls/md.h"
 
-int hkdf_sha256(uint8_t *out_key, size_t out_len,
+int32_t hkdf_sha256(uint8_t *out_key, size_t out_len,
 		const uint8_t *secret, size_t secret_len,
 		const uint8_t *salt, size_t salt_len,
 		const uint8_t *info, size_t info_len)
@@ -36,7 +36,7 @@ int hkdf_sha256(uint8_t *out_key, size_t out_len,
 	return 1;
 }
 
-int hmac_sha256(uint8_t *out_key,
+int32_t hmac_sha256(uint8_t *out_key,
 		const uint8_t *secret, size_t secret_len,
 		const uint8_t *salt, size_t salt_len)
 {
diff --git a/hypervisor/lib/crypto/mbedtls/ChangeLog b/hypervisor/lib/crypto/mbedtls/ChangeLog
index 74583e165..c3bf1f1ed 100644
--- a/hypervisor/lib/crypto/mbedtls/ChangeLog
+++ b/hypervisor/lib/crypto/mbedtls/ChangeLog
@@ -451,7 +451,7 @@ API Changes
      implementations of the RSA interface declared in rsa.h.
    * The following functions in the message digest modules (MD2, MD4, MD5,
      SHA1, SHA256, SHA512) have been deprecated and replaced as shown below.
-     The new functions change the return type from void to int to allow
+     The new functions change the return type from void to int32_t to allow
      returning error codes when using MBEDTLS_<MODULE>_ALT.
      mbedtls_<MODULE>_starts() -> mbedtls_<MODULE>_starts_ret()
      mbedtls_<MODULE>_update() -> mbedtls_<MODULE>_update_ret()
@@ -718,7 +718,7 @@ Features
 API Changes
    * The following functions in the AES module have been deprecated and replaced
      by the functions shown below. The new functions change the return type from
-     void to int to allow returning error codes when using MBEDTLS_AES_ALT,
+     void to int32_t to allow returning error codes when using MBEDTLS_AES_ALT,
      MBEDTLS_AES_DECRYPT_ALT or MBEDTLS_AES_ENCRYPT_ALT.
      mbedtls_aes_decrypt() -> mbedtls_internal_aes_decrypt()
      mbedtls_aes_encrypt() -> mbedtls_internal_aes_encrypt()
@@ -1213,7 +1213,7 @@ API Changes
      ecdsa_write_signature_det() was deprecated.
    * pk_sign() no longer accepts md_alg == POLARSSL_MD_NONE with ECDSA.
    * Last argument of x509_crt_check_key_usage() and
-     mbedtls_x509write_crt_set_key_usage() changed from int to unsigned.
+     mbedtls_x509write_crt_set_key_usage() changed from int32_t to unsigned.
    * test_ca_list (from certs.h) is renamed to test_cas_pem and is only
      available if POLARSSL_PEM_PARSE_C is defined (it never worked without).
    * Test certificates in certs.c are no longer guaranteed to be nul-terminated
@@ -1788,7 +1788,7 @@ Changes
    * Removed POLARSSL_THREADING_DUMMY
 
 Bugfix
-   * Fixed bug in mpi_set_bit() on platforms where t_uint is wider than int
+   * Fixed bug in mpi_set_bit() on platforms where t_uint is wider than int32_t
    * Fixed X.509 hostname comparison (with non-regular characters)
    * SSL now gracefully handles missing RNG
    * Missing defines / cases for RSA_PSK key exchange
@@ -2472,7 +2472,7 @@ Features
 
 Changes
    * Major argument / variable rewrite. Introduced use of size_t
-     instead of int for buffer lengths and loop variables for
+     instead of int32_t for buffer lengths and loop variables for
      better unsigned / signed use. Renamed internal bigint types
      t_int and t_dbl to t_uint and t_udbl in the process
    * mpi_init() and mpi_free() now only accept a single MPI
@@ -2618,7 +2618,7 @@ Changes
    * X509 signature algorithm determination is now
      in a function to allow easy future expansion
    * Changed symmetric cipher functions to
-     identical interface (returning int result values)
+     identical interface (returning int32_t result values)
    * Changed ARC4 to use separate input/output buffer
    * Added reset function for HMAC context as speed-up
      for specific use-cases
diff --git a/hypervisor/lib/crypto/mbedtls/hkdf.c b/hypervisor/lib/crypto/mbedtls/hkdf.c
index fc8caa3b6..9c2b1c9a9 100644
--- a/hypervisor/lib/crypto/mbedtls/hkdf.c
+++ b/hypervisor/lib/crypto/mbedtls/hkdf.c
@@ -21,12 +21,12 @@
 
 #include "hkdf.h"
 
-int mbedtls_hkdf( const mbedtls_md_info_t *md, const uint8_t *salt,
+int32_t mbedtls_hkdf( const mbedtls_md_info_t *md, const uint8_t *salt,
                   size_t salt_len, const uint8_t *ikm, size_t ikm_len,
                   const uint8_t *info, size_t info_len,
                   uint8_t *okm, size_t okm_len )
 {
-    int ret;
+    int32_t ret;
     uint8_t prk[MBEDTLS_MD_MAX_SIZE];
 
     ret = mbedtls_hkdf_extract( md, salt, salt_len, ikm, ikm_len, prk );
@@ -42,7 +42,7 @@ int mbedtls_hkdf( const mbedtls_md_info_t *md, const uint8_t *salt,
     return( ret );
 }
 
-int mbedtls_hkdf_extract( const mbedtls_md_info_t *md,
+int32_t mbedtls_hkdf_extract( const mbedtls_md_info_t *md,
                           const uint8_t *salt, size_t salt_len,
                           const uint8_t *ikm, size_t ikm_len,
                           uint8_t *prk )
@@ -72,7 +72,7 @@ int mbedtls_hkdf_extract( const mbedtls_md_info_t *md,
     return( mbedtls_md_hmac( md, salt, salt_len, ikm, ikm_len, prk ) );
 }
 
-int mbedtls_hkdf_expand( const mbedtls_md_info_t *md, const uint8_t *prk,
+int32_t mbedtls_hkdf_expand( const mbedtls_md_info_t *md, const uint8_t *prk,
                          size_t prk_len, const uint8_t *info,
                          size_t info_len, uint8_t *okm, size_t okm_len )
 {
@@ -81,7 +81,7 @@ int mbedtls_hkdf_expand( const mbedtls_md_info_t *md, const uint8_t *prk,
     size_t n;
     size_t t_len = 0;
     size_t i;
-    int ret = 0;
+    int32_t ret = 0;
     mbedtls_md_context_t ctx;
     uint8_t t[MBEDTLS_MD_MAX_SIZE];
 
diff --git a/hypervisor/lib/crypto/mbedtls/hkdf.h b/hypervisor/lib/crypto/mbedtls/hkdf.h
index a59edbc0f..b2e446ce1 100644
--- a/hypervisor/lib/crypto/mbedtls/hkdf.h
+++ b/hypervisor/lib/crypto/mbedtls/hkdf.h
@@ -60,7 +60,7 @@
  *  \return An MBEDTLS_ERR_MD_* error for errors returned from the underlying
  *          MD layer.
  */
-int mbedtls_hkdf( const mbedtls_md_info_t *md, const uint8_t *salt,
+int32_t mbedtls_hkdf( const mbedtls_md_info_t *md, const uint8_t *salt,
                   size_t salt_len, const uint8_t *ikm, size_t ikm_len,
                   const uint8_t *info, size_t info_len,
                   uint8_t *okm, size_t okm_len );
@@ -84,7 +84,7 @@ int mbedtls_hkdf( const mbedtls_md_info_t *md, const uint8_t *salt,
  *  \return An MBEDTLS_ERR_MD_* error for errors returned from the underlying
  *          MD layer.
  */
-int mbedtls_hkdf_extract( const mbedtls_md_info_t *md,
+int32_t mbedtls_hkdf_extract( const mbedtls_md_info_t *md,
                           const uint8_t *salt, size_t salt_len,
                           const uint8_t *ikm, size_t ikm_len,
                           uint8_t *prk );
@@ -110,7 +110,7 @@ int mbedtls_hkdf_extract( const mbedtls_md_info_t *md,
  *  \return An MBEDTLS_ERR_MD_* error for errors returned from the underlying
  *          MD layer.
  */
-int mbedtls_hkdf_expand( const mbedtls_md_info_t *md, const uint8_t *prk,
+int32_t mbedtls_hkdf_expand( const mbedtls_md_info_t *md, const uint8_t *prk,
                          size_t prk_len, const uint8_t *info,
                          size_t info_len, uint8_t *okm, size_t okm_len );
 
diff --git a/hypervisor/lib/crypto/mbedtls/md.c b/hypervisor/lib/crypto/mbedtls/md.c
index 2b323a409..1ccdf022e 100644
--- a/hypervisor/lib/crypto/mbedtls/md.c
+++ b/hypervisor/lib/crypto/mbedtls/md.c
@@ -31,12 +31,12 @@
 /*
  * Reminder: update profiles in x509_crt.c when adding a new hash!
  */
-static const int supported_digests[] = {
+static const int32_t supported_digests[] = {
         MBEDTLS_MD_SHA256,
         MBEDTLS_MD_NONE
 };
 
-const int *mbedtls_md_list( void )
+const int32_t *mbedtls_md_list( void )
 {
     return( supported_digests );
 }
@@ -65,7 +65,7 @@ void mbedtls_md_free( mbedtls_md_context_t *ctx )
     mbedtls_platform_zeroize( ctx, sizeof( mbedtls_md_context_t ) );
 }
 
-int mbedtls_md_clone( mbedtls_md_context_t *dst,
+int32_t mbedtls_md_clone( mbedtls_md_context_t *dst,
                       const mbedtls_md_context_t *src )
 {
     if( dst == NULL || dst->md_info == NULL ||
@@ -80,7 +80,7 @@ int mbedtls_md_clone( mbedtls_md_context_t *dst,
     return( 0 );
 }
 
-int mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info )
+int32_t mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info )
 {
     if( md_info == NULL || ctx == NULL )
         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
@@ -90,7 +90,7 @@ int mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_inf
     return( 0 );
 }
 
-int mbedtls_md_starts( mbedtls_md_context_t *ctx )
+int32_t mbedtls_md_starts( mbedtls_md_context_t *ctx )
 {
     if( ctx == NULL || ctx->md_info == NULL )
         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
@@ -98,7 +98,7 @@ int mbedtls_md_starts( mbedtls_md_context_t *ctx )
     return( ctx->md_info->starts_func( ctx->md_ctx ) );
 }
 
-int mbedtls_md_update( mbedtls_md_context_t *ctx, const uint8_t *input, size_t ilen )
+int32_t mbedtls_md_update( mbedtls_md_context_t *ctx, const uint8_t *input, size_t ilen )
 {
     if( ctx == NULL || ctx->md_info == NULL )
         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
@@ -106,7 +106,7 @@ int mbedtls_md_update( mbedtls_md_context_t *ctx, const uint8_t *input, size_t i
     return( ctx->md_info->update_func( ctx->md_ctx, input, ilen ) );
 }
 
-int mbedtls_md_finish( mbedtls_md_context_t *ctx, uint8_t *output )
+int32_t mbedtls_md_finish( mbedtls_md_context_t *ctx, uint8_t *output )
 {
     if( ctx == NULL || ctx->md_info == NULL )
         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
@@ -114,7 +114,7 @@ int mbedtls_md_finish( mbedtls_md_context_t *ctx, uint8_t *output )
     return( ctx->md_info->finish_func( ctx->md_ctx, output ) );
 }
 
-int mbedtls_md( const mbedtls_md_info_t *md_info, const uint8_t *input, size_t ilen,
+int32_t mbedtls_md( const mbedtls_md_info_t *md_info, const uint8_t *input, size_t ilen,
             uint8_t *output )
 {
     if( md_info == NULL )
@@ -123,9 +123,9 @@ int mbedtls_md( const mbedtls_md_info_t *md_info, const uint8_t *input, size_t i
     return( md_info->digest_func( input, ilen, output ) );
 }
 
-int mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const uint8_t *key, size_t keylen )
+int32_t mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const uint8_t *key, size_t keylen )
 {
-    int ret;
+    int32_t ret;
     uint8_t sum[MBEDTLS_MD_MAX_SIZE];
     uint8_t *ipad, *opad;
     size_t i;
@@ -170,7 +170,7 @@ cleanup:
     return( ret );
 }
 
-int mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const uint8_t *input, size_t ilen )
+int32_t mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const uint8_t *input, size_t ilen )
 {
     if( ctx == NULL || ctx->md_info == NULL || ctx->hmac_ctx == NULL )
         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
@@ -178,9 +178,9 @@ int mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const uint8_t *input, siz
     return( ctx->md_info->update_func( ctx->md_ctx, input, ilen ) );
 }
 
-int mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, uint8_t *output )
+int32_t mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, uint8_t *output )
 {
-    int ret;
+    int32_t ret;
     uint8_t tmp[MBEDTLS_MD_MAX_SIZE];
     uint8_t *opad;
 
@@ -202,9 +202,9 @@ int mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, uint8_t *output )
     return( ctx->md_info->finish_func( ctx->md_ctx, output ) );
 }
 
-int mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx )
+int32_t mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx )
 {
-    int ret;
+    int32_t ret;
     uint8_t *ipad;
 
     if( ctx == NULL || ctx->md_info == NULL || ctx->hmac_ctx == NULL )
@@ -218,13 +218,13 @@ int mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx )
                                        ctx->md_info->block_size ) );
 }
 
-int mbedtls_md_hmac( const mbedtls_md_info_t *md_info,
+int32_t mbedtls_md_hmac( const mbedtls_md_info_t *md_info,
                      const uint8_t *key, size_t keylen,
                      const uint8_t *input, size_t ilen,
                      uint8_t *output )
 {
     mbedtls_md_context_t ctx;
-    int ret;
+    int32_t ret;
 
     if( md_info == NULL )
         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
@@ -247,7 +247,7 @@ cleanup:
     return( ret );
 }
 
-int mbedtls_md_process( mbedtls_md_context_t *ctx, const uint8_t *data )
+int32_t mbedtls_md_process( mbedtls_md_context_t *ctx, const uint8_t *data )
 {
     if( ctx == NULL || ctx->md_info == NULL )
         return( MBEDTLS_ERR_MD_BAD_INPUT_DATA );
diff --git a/hypervisor/lib/crypto/mbedtls/md.h b/hypervisor/lib/crypto/mbedtls/md.h
index 883c57a17..8c766c636 100644
--- a/hypervisor/lib/crypto/mbedtls/md.h
+++ b/hypervisor/lib/crypto/mbedtls/md.h
@@ -80,7 +80,7 @@ typedef struct {
  *                  message-digest enumeration #mbedtls_md_type_t.
  *                  The last entry is 0.
  */
-const int *mbedtls_md_list( void );
+const int32_t *mbedtls_md_list( void );
 
 /**
  * \brief           This function returns the message-digest information
@@ -135,7 +135,7 @@ void mbedtls_md_free( mbedtls_md_context_t *ctx );
  *                  failure.
  * \return          #MBEDTLS_ERR_MD_ALLOC_FAILED on memory-allocation failure.
  */
-int mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info );
+int32_t mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info );
 
 /**
  * \brief           This function clones the state of an message-digest
@@ -156,7 +156,7 @@ int mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_inf
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.
  */
-int mbedtls_md_clone( mbedtls_md_context_t *dst,
+int32_t mbedtls_md_clone( mbedtls_md_context_t *dst,
                       const mbedtls_md_context_t *src );
 
 /**
@@ -194,7 +194,7 @@ mbedtls_md_type_t mbedtls_md_get_type( const mbedtls_md_info_t *md_info );
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
-int mbedtls_md_starts( mbedtls_md_context_t *ctx );
+int32_t mbedtls_md_starts( mbedtls_md_context_t *ctx );
 
 /**
  * \brief           This function feeds an input buffer into an ongoing
@@ -212,7 +212,7 @@ int mbedtls_md_starts( mbedtls_md_context_t *ctx );
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
-int mbedtls_md_update( mbedtls_md_context_t *ctx, const uint8_t *input, size_t ilen );
+int32_t mbedtls_md_update( mbedtls_md_context_t *ctx, const uint8_t *input, size_t ilen );
 
 /**
  * \brief           This function finishes the digest operation,
@@ -232,7 +232,7 @@ int mbedtls_md_update( mbedtls_md_context_t *ctx, const uint8_t *input, size_t i
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
-int mbedtls_md_finish( mbedtls_md_context_t *ctx, uint8_t *output );
+int32_t mbedtls_md_finish( mbedtls_md_context_t *ctx, uint8_t *output );
 
 /**
  * \brief          This function calculates the message-digest of a buffer,
@@ -252,7 +252,7 @@ int mbedtls_md_finish( mbedtls_md_context_t *ctx, uint8_t *output );
  * \return         #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                 failure.
  */
-int mbedtls_md( const mbedtls_md_info_t *md_info, const uint8_t *input, size_t ilen,
+int32_t mbedtls_md( const mbedtls_md_info_t *md_info, const uint8_t *input, size_t ilen,
         uint8_t *output );
 
 /**
@@ -273,7 +273,7 @@ int mbedtls_md( const mbedtls_md_info_t *md_info, const uint8_t *input, size_t i
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
-int mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const uint8_t *key,
+int32_t mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const uint8_t *key,
                     size_t keylen );
 
 /**
@@ -295,7 +295,7 @@ int mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const uint8_t *key,
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
-int mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const uint8_t *input,
+int32_t mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const uint8_t *input,
                     size_t ilen );
 
 /**
@@ -316,7 +316,7 @@ int mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const uint8_t *input,
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
-int mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, uint8_t *output);
+int32_t mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, uint8_t *output);
 
 /**
  * \brief           This function prepares to authenticate a new message with
@@ -333,7 +333,7 @@ int mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, uint8_t *output);
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
-int mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx );
+int32_t mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx );
 
 /**
  * \brief          This function calculates the full generic HMAC
@@ -357,11 +357,11 @@ int mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx );
  * \return         #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                 failure.
  */
-int mbedtls_md_hmac( const mbedtls_md_info_t *md_info, const uint8_t *key, size_t keylen,
+int32_t mbedtls_md_hmac( const mbedtls_md_info_t *md_info, const uint8_t *key, size_t keylen,
                 const uint8_t *input, size_t ilen,
                 uint8_t *output );
 
 /* Internal use */
-int mbedtls_md_process( mbedtls_md_context_t *ctx, const uint8_t *data );
+int32_t mbedtls_md_process( mbedtls_md_context_t *ctx, const uint8_t *data );
 
 #endif /* MBEDTLS_MD_H */
diff --git a/hypervisor/lib/crypto/mbedtls/md_internal.h b/hypervisor/lib/crypto/mbedtls/md_internal.h
index 9f2053039..c2c58b80f 100644
--- a/hypervisor/lib/crypto/mbedtls/md_internal.h
+++ b/hypervisor/lib/crypto/mbedtls/md_internal.h
@@ -44,29 +44,29 @@ struct mbedtls_md_info_t
     const char * name;
 
     /** Output length of the digest function in bytes */
-    int size;
+    int32_t size;
 
     /** Block length of the digest function in bytes */
-    int block_size;
+    int32_t block_size;
 
     /** Digest initialisation function */
-    int (*starts_func)( void *ctx );
+    int32_t (*starts_func)( void *ctx );
 
     /** Digest update function */
-    int (*update_func)( void *ctx, const uint8_t *input, size_t ilen );
+    int32_t (*update_func)( void *ctx, const uint8_t *input, size_t ilen );
 
     /** Digest finalisation function */
-    int (*finish_func)( void *ctx, uint8_t *output );
+    int32_t (*finish_func)( void *ctx, uint8_t *output );
 
     /** Generic digest function */
-    int (*digest_func)( const uint8_t *input, size_t ilen,
+    int32_t (*digest_func)( const uint8_t *input, size_t ilen,
                         uint8_t *output );
 
     /** Clone state from a context */
     void (*clone_func)( void *dst, const void *src );
 
     /** Internal use only */
-    int (*process_func)( void *ctx, const uint8_t *input );
+    int32_t (*process_func)( void *ctx, const uint8_t *input );
 };
 
 extern const mbedtls_md_info_t mbedtls_sha256_info;
diff --git a/hypervisor/lib/crypto/mbedtls/md_wrap.c b/hypervisor/lib/crypto/mbedtls/md_wrap.c
index 0505e4bba..a9f02327f 100644
--- a/hypervisor/lib/crypto/mbedtls/md_wrap.c
+++ b/hypervisor/lib/crypto/mbedtls/md_wrap.c
@@ -32,14 +32,14 @@
  * Wrappers for generic message digests
  */
 
-static int sha256_update_wrap( void *ctx, const uint8_t *input,
+static int32_t sha256_update_wrap( void *ctx, const uint8_t *input,
                                 size_t ilen )
 {
     return( mbedtls_sha256_update_ret( (mbedtls_sha256_context *) ctx,
                                        input, ilen ) );
 }
 
-static int sha256_finish_wrap( void *ctx, uint8_t *output )
+static int32_t sha256_finish_wrap( void *ctx, uint8_t *output )
 {
     return( mbedtls_sha256_finish_ret( (mbedtls_sha256_context *) ctx,
                                        output ) );
@@ -51,18 +51,18 @@ static void sha256_clone_wrap( void *dst, const void *src )
                     (const mbedtls_sha256_context *) src );
 }
 
-static int sha256_process_wrap( void *ctx, const uint8_t *data )
+static int32_t sha256_process_wrap( void *ctx, const uint8_t *data )
 {
     return( mbedtls_internal_sha256_process( (mbedtls_sha256_context *) ctx,
                                              data ) );
 }
 
-static int sha256_starts_wrap( void *ctx )
+static int32_t sha256_starts_wrap( void *ctx )
 {
     return( mbedtls_sha256_starts_ret( (mbedtls_sha256_context *) ctx, 0 ) );
 }
 
-static int sha256_wrap( const uint8_t *input, size_t ilen,
+static int32_t sha256_wrap( const uint8_t *input, size_t ilen,
                         uint8_t *output )
 {
     return( mbedtls_sha256_ret( input, ilen, output, 0 ) );
diff --git a/hypervisor/lib/crypto/mbedtls/sha256.c b/hypervisor/lib/crypto/mbedtls/sha256.c
index af6ca21ea..f397f0933 100644
--- a/hypervisor/lib/crypto/mbedtls/sha256.c
+++ b/hypervisor/lib/crypto/mbedtls/sha256.c
@@ -73,7 +73,7 @@ void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
 /*
  * SHA-256 context setup
  */
-int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 )
+int32_t mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int32_t is224 )
 {
     ctx->total[0] = 0;
     ctx->total[1] = 0;
@@ -153,7 +153,7 @@ static const uint32_t K[] =
     d += temp1; h = temp1 + temp2;              \
 }
 
-int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
+int32_t mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
                                 const uint8_t data[64] )
 {
     uint32_t temp1, temp2, W[64];
@@ -199,11 +199,11 @@ int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
 /*
  * SHA-256 process buffer
  */
-int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
+int32_t mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
                                const uint8_t *input,
                                size_t ilen )
 {
-    int ret;
+    int32_t ret;
     size_t fill;
     uint32_t left;
 
@@ -249,10 +249,10 @@ int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
 /*
  * SHA-256 final digest
  */
-int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
+int32_t mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
                                uint8_t output[32] )
 {
-    int ret;
+    int32_t ret;
     uint32_t used;
     uint32_t high, low;
 
@@ -312,12 +312,12 @@ int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
 /*
  * output = SHA-256( input buffer )
  */
-int mbedtls_sha256_ret( const uint8_t *input,
+int32_t mbedtls_sha256_ret( const uint8_t *input,
                         size_t ilen,
                         uint8_t output[32],
-                        int is224 )
+                        int32_t is224 )
 {
-    int ret;
+    int32_t ret;
     mbedtls_sha256_context ctx;
 
     mbedtls_sha256_init( &ctx );
diff --git a/hypervisor/lib/crypto/mbedtls/sha256.h b/hypervisor/lib/crypto/mbedtls/sha256.h
index a6f2662c8..16ce106ff 100644
--- a/hypervisor/lib/crypto/mbedtls/sha256.h
+++ b/hypervisor/lib/crypto/mbedtls/sha256.h
@@ -43,7 +43,7 @@ typedef struct
     uint32_t total[2];          /*!< The number of Bytes processed.  */
     uint32_t state[8];          /*!< The intermediate digest state.  */
     uint8_t buffer[64];   /*!< The data block being processed. */
-    int is224;                  /*!< Determines which function to use:
+    int32_t is224;                  /*!< Determines which function to use:
                                      0: Use SHA-256, or 1: Use SHA-224. */
 }
 mbedtls_sha256_context;
@@ -81,7 +81,7 @@ void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
  *
  * \return         \c 0 on success.
  */
-int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 );
+int32_t mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int32_t is224 );
 
 /**
  * \brief          This function feeds an input buffer into an ongoing
@@ -93,7 +93,7 @@ int mbedtls_sha256_starts_ret( mbedtls_sha256_context *ctx, int is224 );
  *
  * \return         \c 0 on success.
  */
-int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
+int32_t mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
                                const uint8_t *input,
                                size_t ilen );
 
@@ -106,7 +106,7 @@ int mbedtls_sha256_update_ret( mbedtls_sha256_context *ctx,
  *
  * \return         \c 0 on success.
  */
-int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
+int32_t mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
                                uint8_t output[32] );
 
 /**
@@ -119,7 +119,7 @@ int mbedtls_sha256_finish_ret( mbedtls_sha256_context *ctx,
  *
  * \return         \c 0 on success.
  */
-int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
+int32_t mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
                                      const uint8_t data[64] );
 
 /**
@@ -138,9 +138,9 @@ int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
  * \param is224    Determines which function to use:
  *                 0: Use SHA-256, or 1: Use SHA-224.
  */
-int mbedtls_sha256_ret( const uint8_t *input,
+int32_t mbedtls_sha256_ret( const uint8_t *input,
                         size_t ilen,
                         uint8_t output[32],
-                        int is224 );
+                        int32_t is224 );
 
 #endif /* mbedtls_sha256.h */
diff --git a/hypervisor/lib/memory.c b/hypervisor/lib/memory.c
index 9197f4e8a..9b0974e1b 100644
--- a/hypervisor/lib/memory.c
+++ b/hypervisor/lib/memory.c
@@ -259,7 +259,7 @@ void free(const void *ptr)
 	}
 }
 
-void *memchr(const void *void_s, int c, size_t n)
+void *memchr(const void *void_s, int32_t c, size_t n)
 {
 	uint8_t val = (uint8_t)c;
 	uint8_t *ptr = (uint8_t *)void_s;
diff --git a/hypervisor/lib/string.c b/hypervisor/lib/string.c
index a9c566fb5..8c51b1ca6 100644
--- a/hypervisor/lib/string.c
+++ b/hypervisor/lib/string.c
@@ -37,7 +37,7 @@ long strtol_deci(const char *nptr)
 	const char *s = nptr;
 	char c;
 	uint64_t acc, cutoff, cutlim;
-	int neg = 0, any;
+	int32_t neg = 0, any;
 	uint64_t base = 10UL;
 
 	/*
@@ -117,7 +117,7 @@ uint64_t strtoul_hex(const char *nptr)
 	char c, digit;
 	uint64_t acc, cutoff, cutlim;
 	uint64_t base = 16UL;
-	int any;
+	int32_t any;
 
 	/*
 	 * See strtol for comments as to the logic used.
@@ -157,9 +157,9 @@ uint64_t strtoul_hex(const char *nptr)
 	return acc;
 }
 
-int atoi(const char *str)
+int32_t atoi(const char *str)
 {
-	return (int)strtol_deci(str);
+	return (int32_t)strtol_deci(str);
 }
 
 char *strchr(char *s_arg, char ch)
@@ -377,7 +377,7 @@ size_t strnlen_s(const char *str_arg, size_t maxlen_arg)
 	return count;
 }
 
-int strcmp(const char *s1_arg, const char *s2_arg)
+int32_t strcmp(const char *s1_arg, const char *s2_arg)
 {
 	const char *s1 = s1_arg;
 	const char *s2 = s2_arg;
@@ -389,7 +389,7 @@ int strcmp(const char *s1_arg, const char *s2_arg)
 	return *s1 - *s2;
 }
 
-int strncmp(const char *s1_arg, const char *s2_arg, size_t n_arg)
+int32_t strncmp(const char *s1_arg, const char *s2_arg, size_t n_arg)
 {
 	const char *s1 = s1_arg;
 	const char *s2 = s2_arg;
diff --git a/hypervisor/partition/apl-mrb/mptable.c b/hypervisor/partition/apl-mrb/mptable.c
index 04fe4503d..4359e9726 100644
--- a/hypervisor/partition/apl-mrb/mptable.c
+++ b/hypervisor/partition/apl-mrb/mptable.c
@@ -288,7 +288,7 @@ static uint8_t mpt_compute_checksum(void *base, size_t len)
 	return (256U - sum);
 }
 
-int mptable_build(struct acrn_vm *vm)
+int32_t mptable_build(struct acrn_vm *vm)
 {
 	char                    *startaddr;
 	char                    *curraddr;
diff --git a/hypervisor/partition/cb2_dnv/mptable.c b/hypervisor/partition/cb2_dnv/mptable.c
index 0888cf2c9..cc92730af 100644
--- a/hypervisor/partition/cb2_dnv/mptable.c
+++ b/hypervisor/partition/cb2_dnv/mptable.c
@@ -320,7 +320,7 @@ static uint8_t mpt_compute_checksum(void *base, size_t len)
 	return (256U - sum);
 }
 
-int mptable_build(struct acrn_vm *vm)
+int32_t mptable_build(struct acrn_vm *vm)
 {
 	char                    *startaddr;
 	char                    *curraddr;