kvm tools: Fixes for serial module

Fixes include:
 - Error handling
 - Cleanup
 - Standard init/uninit

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>

builtin-run.c

@@ -1115,7 +1115,11 @@ static int kvm_cmd_run_init(int argc, const char **argv)
 
 	rtc__init();
 
-	serial8250__init(kvm);
+	r = serial8250__init(kvm);
+	if (r < 0) {
+		pr_err("serial__init() failed with error %d\n", r);
+		goto fail;
+	}
 
 	if (active_console == CONSOLE_VIRTIO)
 		virtio_console__init(kvm);
@@ -1224,6 +1228,7 @@ static int kvm_cmd_run_work(void)
 		r = 0;
 
 	kvm_cpu__delete(kvm_cpus[0]);
+	kvm_cpus[0] = NULL;
 
 	for (i = 1; i < nrcpus; i++) {
 		if (kvm_cpus[i]->is_running) {
@@ -1261,6 +1266,10 @@ static void kvm_cmd_run_exit(int guest_ret)
 	disk_image__close_all(kvm->disks, image_count);
 	free(kvm_cpus);
 
+	r = serial8250__exit(kvm);
+	if (r < 0)
+		pr_warning("serial8250__exit() failed with error %d\n", r);
+
 	r = ioport__exit(kvm);
 	if (r < 0)
 		pr_warning("ioport__exit() failed with error %d\n", r);

hw/serial.c

@@ -396,19 +396,52 @@ static struct ioport_operations serial8250_ops = {
 	.io_out		= serial8250_out,
 };
 
-static void serial8250__device_init(struct kvm *kvm, struct serial8250_device *dev)
+static int serial8250__device_init(struct kvm *kvm, struct serial8250_device *dev)
 {
-	ioport__register(dev->iobase, &serial8250_ops, 8, NULL);
+	int r;
+
+	r = ioport__register(dev->iobase, &serial8250_ops, 8, NULL);
 	kvm__irq_line(kvm, dev->irq, 0);
+
+	return r;
 }
 
-void serial8250__init(struct kvm *kvm)
+int serial8250__init(struct kvm *kvm)
 {
-	unsigned int i;
+	unsigned int i, j;
+	int r = 0;
 
 	for (i = 0; i < ARRAY_SIZE(devices); i++) {
 		struct serial8250_device *dev = &devices[i];
 
-		serial8250__device_init(kvm, dev);
+		r = serial8250__device_init(kvm, dev);
+		if (r < 0)
+			goto cleanup;
 	}
+
+	return r;
+cleanup:
+	for (j = 0; j <= i; j++) {
+		struct serial8250_device *dev = &devices[j];
+
+		ioport__unregister(dev->iobase);
+	}
+
+	return r;
+}
+
+int serial8250__exit(struct kvm *kvm)
+{
+	unsigned int i;
+	int r;
+
+	for (i = 0; i < ARRAY_SIZE(devices); i++) {
+		struct serial8250_device *dev = &devices[i];
+
+		r = ioport__unregister(dev->iobase);
+		if (r < 0)
+			return r;
+	}
+
+	return 0;
 }

include/kvm/8250-serial.h

@@ -3,7 +3,8 @@
 
 struct kvm;
 
-void serial8250__init(struct kvm *kvm);
+int serial8250__init(struct kvm *kvm);
+int serial8250__exit(struct kvm *kvm);
 void serial8250__update_consoles(struct kvm *kvm);
 void serial8250__inject_sysrq(struct kvm *kvm);