diff --git a/devices/src/acpi.rs b/devices/src/acpi.rs
index cc640bb1e..395e9b25b 100644
--- a/devices/src/acpi.rs
+++ b/devices/src/acpi.rs
@@ -8,9 +8,12 @@ use std::sync::{Arc, Barrier};
 use std::time::Instant;
 use vm_device::interrupt::InterruptSourceGroup;
 use vm_device::BusDevice;
+use vm_memory::GuestAddress;
 use vmm_sys_util::eventfd::EventFd;
 use AcpiNotificationFlags;
 
+pub const GED_DEVICE_ACPI_SIZE: usize = 0x1;
+
 /// A device for handling ACPI shutdown and reboot
 pub struct AcpiShutdownDevice {
     exit_evt: EventFd,
@@ -63,14 +66,20 @@ pub struct AcpiGEDDevice {
     interrupt: Arc<Box<dyn InterruptSourceGroup>>,
     notification_type: AcpiNotificationFlags,
     ged_irq: u32,
+    address: GuestAddress,
 }
 
 impl AcpiGEDDevice {
-    pub fn new(interrupt: Arc<Box<dyn InterruptSourceGroup>>, ged_irq: u32) -> AcpiGEDDevice {
+    pub fn new(
+        interrupt: Arc<Box<dyn InterruptSourceGroup>>,
+        ged_irq: u32,
+        address: GuestAddress,
+    ) -> AcpiGEDDevice {
         AcpiGEDDevice {
             interrupt,
             notification_type: AcpiNotificationFlags::NO_DEVICES_CHANGED,
             ged_irq,
+            address,
         }
     }
 
@@ -114,7 +123,12 @@ impl Aml for AcpiGEDDevice {
                         self.ged_irq,
                     )]),
                 ),
-                &aml::OpRegion::new("GDST".into(), aml::OpRegionSpace::SystemIO, 0xb000, 0x1),
+                &aml::OpRegion::new(
+                    "GDST".into(),
+                    aml::OpRegionSpace::SystemMemory,
+                    self.address.0 as usize,
+                    GED_DEVICE_ACPI_SIZE,
+                ),
                 &aml::Field::new(
                     "GDST".into(),
                     aml::FieldAccessType::Byte,
diff --git a/devices/src/lib.rs b/devices/src/lib.rs
index 4d2f260a0..0f42f367a 100644
--- a/devices/src/lib.rs
+++ b/devices/src/lib.rs
@@ -26,7 +26,7 @@ extern crate serde_derive;
 extern crate serde_json;
 
 #[cfg(feature = "acpi")]
-mod acpi;
+pub mod acpi;
 #[cfg(target_arch = "aarch64")]
 pub mod gic;
 pub mod interrupt_controller;
diff --git a/vmm/src/device_manager.rs b/vmm/src/device_manager.rs
index 664038f0f..8fc481951 100644
--- a/vmm/src/device_manager.rs
+++ b/vmm/src/device_manager.rs
@@ -244,6 +244,9 @@ pub enum DeviceManagerError {
     /// Failed to allocate IO port
     AllocateIOPort,
 
+    /// Failed to allocate MMIO address
+    AllocateMMIOAddress,
+
     // Failed to make hotplug notification
     HotPlugNotification(io::Error),
 
@@ -1210,32 +1213,33 @@ impl DeviceManager {
             .unwrap()
             .allocate_irq()
             .unwrap();
-
         let interrupt_group = interrupt_manager
             .create_group(LegacyIrqGroupConfig {
                 irq: ged_irq as InterruptIndex,
             })
             .map_err(DeviceManagerError::CreateInterruptGroup)?;
-
-        let ged_device = Arc::new(Mutex::new(devices::AcpiGEDDevice::new(
-            interrupt_group,
-            ged_irq,
-        )));
-
-        self.bus_devices
-            .push(Arc::clone(&ged_device) as Arc<Mutex<dyn BusDevice>>);
-
-        self.address_manager
+        let ged_address = self
+            .address_manager
             .allocator
             .lock()
             .unwrap()
-            .allocate_io_addresses(Some(GuestAddress(0xb000)), 0x1, None)
-            .ok_or(DeviceManagerError::AllocateIOPort)?;
-
+            .allocate_mmio_addresses(None, devices::acpi::GED_DEVICE_ACPI_SIZE as u64, None)
+            .ok_or(DeviceManagerError::AllocateMMIOAddress)?;
+        let ged_device = Arc::new(Mutex::new(devices::AcpiGEDDevice::new(
+            interrupt_group,
+            ged_irq,
+            ged_address,
+        )));
         self.address_manager
-            .io_bus
-            .insert(ged_device.clone(), 0xb000, 0x1)
+            .mmio_bus
+            .insert(
+                ged_device.clone(),
+                ged_address.0,
+                devices::acpi::GED_DEVICE_ACPI_SIZE as u64,
+            )
             .map_err(DeviceManagerError::BusError)?;
+        self.bus_devices
+            .push(Arc::clone(&ged_device) as Arc<Mutex<dyn BusDevice>>);
 
         let pm_timer_device = Arc::new(Mutex::new(devices::AcpiPMTimerDevice::new()));