diff --git a/hw/acpi.c b/hw/acpi.c
index 37a5d9823b..6eddd0ec5d 100644
--- a/hw/acpi.c
+++ b/hw/acpi.c
@@ -440,46 +440,33 @@ static void pm_write_config(PCIDevice *d,
         pm_io_space_update((PIIX4PMState *)d);
 }
 
-static void pm_save(QEMUFile* f,void *opaque)
+static int vmstate_acpi_after_load(void *opaque)
 {
     PIIX4PMState *s = opaque;
 
-    pci_device_save(&s->dev, f);
-
-    qemu_put_be16s(f, &s->pmsts);
-    qemu_put_be16s(f, &s->pmen);
-    qemu_put_be16s(f, &s->pmcntrl);
-    qemu_put_8s(f, &s->apmc);
-    qemu_put_8s(f, &s->apms);
-    qemu_put_timer(f, s->tmr_timer);
-    qemu_put_be64(f, s->tmr_overflow_time);
-}
-
-static int pm_load(QEMUFile* f,void* opaque,int version_id)
-{
-    PIIX4PMState *s = opaque;
-    int ret;
-
-    if (version_id > 1)
-        return -EINVAL;
-
-    ret = pci_device_load(&s->dev, f);
-    if (ret < 0)
-        return ret;
-
-    qemu_get_be16s(f, &s->pmsts);
-    qemu_get_be16s(f, &s->pmen);
-    qemu_get_be16s(f, &s->pmcntrl);
-    qemu_get_8s(f, &s->apmc);
-    qemu_get_8s(f, &s->apms);
-    qemu_get_timer(f, s->tmr_timer);
-    s->tmr_overflow_time=qemu_get_be64(f);
-
     pm_io_space_update(s);
-
     return 0;
 }
 
+static const VMStateDescription vmstate_acpi = {
+    .name = "piix4_pm",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .run_after_load = vmstate_acpi_after_load,
+    .fields      = (VMStateField []) {
+        VMSTATE_PCI_DEVICE(dev, PIIX4PMState),
+        VMSTATE_UINT16(pmsts, PIIX4PMState),
+        VMSTATE_UINT16(pmen, PIIX4PMState),
+        VMSTATE_UINT16(pmcntrl, PIIX4PMState),
+        VMSTATE_UINT8(apmc, PIIX4PMState),
+        VMSTATE_UINT8(apms, PIIX4PMState),
+        VMSTATE_TIMER(tmr_timer, PIIX4PMState),
+        VMSTATE_INT64(tmr_overflow_time, PIIX4PMState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 static void piix4_reset(void *opaque)
 {
     PIIX4PMState *s = opaque;
@@ -561,7 +548,7 @@ i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
 
     qemu_system_powerdown = *qemu_allocate_irqs(piix4_powerdown, s, 1);
 
-    register_savevm("piix4_pm", 0, 1, pm_save, pm_load, s);
+    vmstate_register(0, &vmstate_acpi, s);
 
     s->smbus = i2c_init_bus(NULL, "i2c");
     s->irq = sci_irq;