diff --git a/hw/serial.c b/hw/serial.c
index 0ee61dd..7a63b7d 100644
--- a/hw/serial.c
+++ b/hw/serial.c
@@ -161,6 +161,8 @@ typedef struct ISASerialState {
     uint32_t iobase;
     uint32_t isairq;
     SerialState state;
+    uint32_t initial_iobase;
+    uint32_t initial_isairq;
 } ISASerialState;
 
 static void serial_receive1(void *opaque, const uint8_t *buf, int size);
@@ -752,6 +754,31 @@ void serial_set_frequency(SerialState *s, uint32_t frequency)
     serial_update_parameters(s);
 }
 
+static int serial_isa_enable(ISADevice *dev)
+{
+    ISASerialState *isa = DO_UPCAST(ISASerialState, dev, dev);
+    SerialState *s = &isa->state;
+
+    isa_init_irq(dev, &s->irq, isa->isairq);
+
+    register_ioport_write(isa->iobase, 8, 1, serial_ioport_write, s);
+    register_ioport_read(isa->iobase, 8, 1, serial_ioport_read, s);
+    isa_init_ioport_range(dev, isa->iobase, 8);
+    return 0;
+}
+
+static int serial_isa_disable(ISADevice *dev)
+{
+    ISASerialState *isa = DO_UPCAST(ISASerialState, dev, dev);
+    SerialState *s = &isa->state;
+
+    isa_uninit_irq(dev, &s->irq, isa->isairq);
+
+    isa_discard_ioport_range(dev, isa->iobase, 8);
+    isa_unassign_ioport(isa->iobase, 8);
+    return 0;
+}
+
 static const int isa_serial_io[MAX_SERIAL_PORTS] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8 };
 static const int isa_serial_irq[MAX_SERIAL_PORTS] = { 4, 3, 4, 3 };
 
@@ -771,25 +798,76 @@ static int serial_isa_initfn(ISADevice *dev)
         isa->isairq = isa_serial_irq[isa->index];
     index++;
 
+    isa->initial_iobase = isa->iobase;
+    isa->initial_isairq = isa->isairq;
+
     s->baudbase = 115200;
-    isa_init_irq(dev, &s->irq, isa->isairq);
     serial_init_core(s);
     qdev_set_legacy_instance_id(&dev->qdev, isa->iobase, 3);
 
-    register_ioport_write(isa->iobase, 8, 1, serial_ioport_write, s);
-    register_ioport_read(isa->iobase, 8, 1, serial_ioport_read, s);
-    isa_init_ioport_range(dev, isa->iobase, 8);
+    if (dev->enabled) {
+        serial_isa_enable(dev);
+    }
     return 0;
 }
 
+static int serial_isa_pre_load(void *opaque)
+{
+    ISASerialState *s = opaque;
+
+    isa_set_state(&s->dev, false);
+    return 0;
+}
+
+static int serial_isa_post_load(void *opaque, int version_id)
+{
+    ISASerialState *s = opaque;
+    ISADevice *dev = &s->dev;
+
+    if (dev->enabled) {
+        serial_isa_enable(dev);
+    }
+    return 0;
+}
+
+static bool serial_isa_config_needed(void *opaque)
+{
+    ISASerialState *s = opaque;
+
+    return isa_vmstate_needed(&s->dev) ||
+        s->initial_iobase != s->iobase ||
+        s->initial_isairq != s->isairq;
+}
+
+static const VMStateDescription vmstate_isa_serial_isaconfig = {
+    .name = "serial/isa-config",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField []) {
+        VMSTATE_ISA_DEVICE(dev, ISASerialState),
+        VMSTATE_UINT32(iobase, ISASerialState),
+        VMSTATE_UINT32(isairq, ISASerialState),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
 static const VMStateDescription vmstate_isa_serial = {
     .name = "serial",
     .version_id = 3,
     .minimum_version_id = 2,
+    .pre_load  = serial_isa_pre_load,
+    .post_load = serial_isa_post_load,
     .fields      = (VMStateField []) {
         VMSTATE_STRUCT(state, ISASerialState, 0, vmstate_serial, SerialState),
         VMSTATE_END_OF_LIST()
-    }
+    },
+    .subsections = (VMStateSubsection []) {
+        {
+            .vmsd = &vmstate_isa_serial_isaconfig,
+            .needed = serial_isa_config_needed,
+        }, {
+        }
+    },
 };
 
 SerialState *serial_init(int base, qemu_irq irq, int baudbase,
@@ -962,11 +1040,14 @@ static ISADeviceInfo serial_isa_info = {
     .qdev.size  = sizeof(ISASerialState),
     .qdev.vmsd  = &vmstate_isa_serial,
     .init       = serial_isa_initfn,
+    .enable     = serial_isa_enable,
+    .disable    = serial_isa_disable,
     .qdev.props = (Property[]) {
         DEFINE_PROP_UINT32("index", ISASerialState, index,   -1),
         DEFINE_PROP_HEX32("iobase", ISASerialState, iobase,  -1),
         DEFINE_PROP_UINT32("irq",   ISASerialState, isairq,  -1),
         DEFINE_PROP_CHR("chardev",  ISASerialState, state.chr),
+        DEFINE_PROP_BOOL("enabled", ISASerialState, dev.enabled, true),
         DEFINE_PROP_END_OF_LIST(),
     },
 };
