Pass VM config by FD rather than filename.

Bug: 184131756
Test: atest VirtualizationTestCases
Change-Id: Iba739bc8de941b68a88090438743d9f54ba0380c
diff --git a/virtmanager/src/crosvm.rs b/virtmanager/src/crosvm.rs
index 814a1a7..c865357 100644
--- a/virtmanager/src/crosvm.rs
+++ b/virtmanager/src/crosvm.rs
@@ -30,27 +30,19 @@
     child: Child,
     /// The CID assigned to the VM for vsock communication.
     pub cid: Cid,
-    /// The filename of the config file that was used to start the VM. This may have changed since
-    /// it was read so it shouldn't be trusted; it is only stored for debugging purposes.
-    pub config_path: String,
 }
 
 impl VmInstance {
     /// Create a new `VmInstance` for the given process.
-    fn new(child: Child, cid: Cid, config_path: &str) -> VmInstance {
-        VmInstance { child, cid, config_path: config_path.to_owned() }
+    fn new(child: Child, cid: Cid) -> VmInstance {
+        VmInstance { child, cid }
     }
 
     /// Start an instance of `crosvm` to manage a new VM. The `crosvm` instance will be killed when
     /// the `VmInstance` is dropped.
-    pub fn start(
-        config: &VmConfig,
-        cid: Cid,
-        config_path: &str,
-        log_fd: Option<File>,
-    ) -> Result<VmInstance, Error> {
+    pub fn start(config: &VmConfig, cid: Cid, log_fd: Option<File>) -> Result<VmInstance, Error> {
         let child = run_vm(config, cid, log_fd)?;
-        Ok(VmInstance::new(child, cid, config_path))
+        Ok(VmInstance::new(child, cid))
     }
 }