diff --git a/hypervisor/arch/x86/guest/guest.c b/hypervisor/arch/x86/guest/guest.c
index aff939997..5f143093a 100644
--- a/hypervisor/arch/x86/guest/guest.c
+++ b/hypervisor/arch/x86/guest/guest.c
@@ -79,7 +79,8 @@ inline uint64_t vcpumask2pcpumask(struct vm *vm, uint64_t vdmask)
 	uint64_t dmask = 0;
 	struct vcpu *vcpu;
 
-	while ((vcpu_id = ffs64(vdmask)) != INVALID_BIT_INDEX) {
+	for (vcpu_id = ffs64(vdmask); vcpu_id != INVALID_BIT_INDEX;
+		vcpu_id = ffs64(vdmask)) {
 		bitmap_clear(vcpu_id, &vdmask);
 		vcpu = vcpu_from_vid(vm, vcpu_id);
 		ASSERT(vcpu != NULL, "vcpu_from_vid failed");
diff --git a/hypervisor/arch/x86/guest/vlapic.c b/hypervisor/arch/x86/guest/vlapic.c
index baca397c8..64d4c15e9 100644
--- a/hypervisor/arch/x86/guest/vlapic.c
+++ b/hypervisor/arch/x86/guest/vlapic.c
@@ -912,7 +912,8 @@ vlapic_calcdest(struct vm *vm, uint64_t *dmask, uint32_t dest,
 		 */
 		*dmask = 0UL;
 		amask = vm_active_cpus(vm);
-		while ((vcpu_id = ffs64(amask)) != INVALID_BIT_INDEX) {
+		for (vcpu_id = ffs64(amask); vcpu_id != INVALID_BIT_INDEX;
+			vcpu_id = ffs64(amask)) {
 			bitmap_clear(vcpu_id, &amask);
 
 			vlapic = vm_lapic_from_vcpu_id(vm, vcpu_id);
@@ -1613,7 +1614,8 @@ vlapic_deliver_intr(struct vm *vm, bool level, uint32_t dest, bool phys,
 	 */
 	vlapic_calcdest(vm, &dmask, dest, phys, lowprio);
 
-	while ((vcpu_id = ffs64(dmask)) != INVALID_BIT_INDEX) {
+	for (vcpu_id = ffs64(dmask); vcpu_id != INVALID_BIT_INDEX;
+		vcpu_id = ffs64(dmask)) {
 		bitmap_clear(vcpu_id, &dmask);
 		target_vcpu = vcpu_from_vid(vm, vcpu_id);
 		if (target_vcpu == NULL)
@@ -1759,7 +1761,8 @@ vlapic_set_local_intr(struct vm *vm, uint16_t vcpu_id, uint32_t vector)
 	else
 		bitmap_set(vcpu_id, &dmask);
 	error = 0;
-	while ((vcpu_id = ffs64(dmask)) != INVALID_BIT_INDEX) {
+	for (vcpu_id = ffs64(dmask); vcpu_id != INVALID_BIT_INDEX;
+		vcpu_id = ffs64(dmask)) {
 		bitmap_clear(vcpu_id, &dmask);
 		vlapic = vm_lapic_from_vcpu_id(vm, vcpu_id);
 		error = vlapic_trigger_lvt(vlapic, vector);
diff --git a/hypervisor/debug/serial.c b/hypervisor/debug/serial.c
index 5386654e0..b71e4cd3a 100644
--- a/hypervisor/debug/serial.c
+++ b/hypervisor/debug/serial.c
@@ -143,8 +143,9 @@ uint32_t serial_get_rx_data(uint32_t uart_handle)
 		return 0U;
 
 	/* Place all the data available in RX FIFO, in circular buffer */
-	while ((data_avail = uart->tgt_uart->rx_data_is_avail(
-				uart->tgt_uart, &lsr_reg)) != 0) {
+	data_avail = uart->tgt_uart->rx_data_is_avail(
+				uart->tgt_uart, &lsr_reg);
+	while (data_avail != 0) {
 
 		/* Read the byte */
 		uart->tgt_uart->read(uart->tgt_uart, (void *)&ch, &bytes_read);
@@ -178,6 +179,8 @@ uint32_t serial_get_rx_data(uint32_t uart_handle)
 		}
 		/* Update the total bytes read */
 		total_bytes_read += bytes_read;
+		data_avail = uart->tgt_uart->rx_data_is_avail(
+				uart->tgt_uart, &lsr_reg);
 	}
 	return total_bytes_read;
 }