vmm, vm-allocator: Introduce an allocator for platform devices

This allocator allocates 64-bit MMIO addresses for use with platform
devices e.g. ACPI control devices and ensures there is no overlap with
PCI address space ranges which can cause issues with PCI device
remapping.

Use this allocator the ACPI platform devices.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

vmm/src/device_manager.rs

@@ -975,7 +975,7 @@ impl DeviceManager {
             .allocator
             .lock()
             .unwrap()
-            .allocate_mmio_addresses(None, DEVICE_MANAGER_ACPI_SIZE as u64, None)
+            .allocate_platform_mmio_addresses(None, DEVICE_MANAGER_ACPI_SIZE as u64, None)
             .ok_or(DeviceManagerError::AllocateIoPort)?;
 
         let mut pci_irq_slots = [0; 32];
@@ -1366,7 +1366,11 @@ impl DeviceManager {
             .allocator
             .lock()
             .unwrap()
-            .allocate_mmio_addresses(None, devices::acpi::GED_DEVICE_ACPI_SIZE as u64, None)
+            .allocate_platform_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,