Refactor: move load_vm_config to associated function on VmConfig.

Bug: 171277638
Test: m virtmanager
Change-Id: I94ff72693dc9e1b654827591bd233e95bd35743e
diff --git a/virtmanager/src/aidl.rs b/virtmanager/src/aidl.rs
index 1b3819f..b7595a9 100644
--- a/virtmanager/src/aidl.rs
+++ b/virtmanager/src/aidl.rs
@@ -14,7 +14,7 @@
 
 //! Implementation of the AIDL interface of the Virt Manager.
 
-use crate::config::load_vm_config;
+use crate::config::VmConfig;
 use crate::crosvm::VmInstance;
 use crate::{Cid, FIRST_GUEST_CID};
 use android_system_virtmanager::aidl::android::system::virtmanager::IVirtManager::IVirtManager;
@@ -141,7 +141,7 @@
 /// Start a new VM instance from the given VM config filename. This assumes the VM is not already
 /// running.
 fn start_vm(config_path: &str, cid: Cid) -> binder::Result<VmInstance> {
-    let config = load_vm_config(config_path).map_err(|e| {
+    let config = VmConfig::load(config_path).map_err(|e| {
         error!("Failed to load VM config {}: {:?}", config_path, e);
         StatusCode::BAD_VALUE
     })?;
diff --git a/virtmanager/src/config.rs b/virtmanager/src/config.rs
index c0d23f0..d8cb06f 100644
--- a/virtmanager/src/config.rs
+++ b/virtmanager/src/config.rs
@@ -49,6 +49,13 @@
         }
         Ok(())
     }
+
+    /// Load the configuration for a VM from the given JSON file.
+    pub fn load(path: &str) -> Result<VmConfig, Error> {
+        let file = File::open(path).with_context(|| format!("Failed to open {}", path))?;
+        let buffered = BufReader::new(file);
+        Ok(serde_json::from_reader(buffered)?)
+    }
 }
 
 /// A disk image to be made available to the VM.
@@ -59,10 +66,3 @@
     /// Whether this disk should be writable by the VM.
     pub writable: bool,
 }
-
-/// Load the configuration for the VM with the given ID from a JSON file.
-pub fn load_vm_config(path: &str) -> Result<VmConfig, Error> {
-    let file = File::open(path).with_context(|| format!("Failed to open {}", path))?;
-    let buffered = BufReader::new(file);
-    Ok(serde_json::from_reader(buffered)?)
-}