diff --git a/src/dragonball/src/dbs_virtio_devices/src/vhost/vhost_user/connection.rs b/src/dragonball/src/dbs_virtio_devices/src/vhost/vhost_user/connection.rs
index 43b1a96d66..9b3dabd41f 100644
--- a/src/dragonball/src/dbs_virtio_devices/src/vhost/vhost_user/connection.rs
+++ b/src/dragonball/src/dbs_virtio_devices/src/vhost/vhost_user/connection.rs
@@ -25,6 +25,9 @@ use crate::{Error as VirtioError, Result as VirtioResult};
 
 enum EndpointProtocolFlags {
     ProtocolMq = 1,
+    #[allow(dead_code)]
+    #[cfg(feature = "vhost-user-blk")]
+    ProtocolBackend = 2,
 }
 
 pub(super) struct Listener {
diff --git a/src/dragonball/src/device_manager/mod.rs b/src/dragonball/src/device_manager/mod.rs
index d50294471f..f0958b1166 100644
--- a/src/dragonball/src/device_manager/mod.rs
+++ b/src/dragonball/src/device_manager/mod.rs
@@ -1038,9 +1038,7 @@ impl DeviceManager {
     pub fn get_pci_bus_resources(&self) -> Option<PciBusResources> {
         let mut vfio_dev_mgr = self.vfio_manager.lock().unwrap();
         let vfio_pci_mgr = vfio_dev_mgr.get_pci_manager();
-        if vfio_pci_mgr.is_none() {
-            return None;
-        }
+        vfio_pci_mgr.as_ref()?;
         let pci_manager = vfio_pci_mgr.unwrap();
         let ecam_space = pci_manager.get_ecam_space();
         let bar_space = pci_manager.get_bar_space();