snapshot-editor: always create at current version

Have snapshot-editor always create a snapshot at the current version. We
cannot load snapshots that have a different snapshot version than is
supported by the running binary anyway (because strongly-typed
deserialization would fail), so we statically know that the `version`
parameter to `save_vmstate` is always `SNAPSHOT_VERSION`.

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

src/snapshot-editor/src/edit_vmstate.rs

@@ -51,9 +51,9 @@ fn edit(
     output_path: &PathBuf,
     f: impl Fn(MicrovmState) -> Result<MicrovmState, EditVmStateError>,
 ) -> Result<(), EditVmStateError> {
-    let (microvm_state, version) = open_vmstate(vmstate_path)?;
+    let (microvm_state, _) = open_vmstate(vmstate_path)?;
     let microvm_state = f(microvm_state)?;
-    save_vmstate(microvm_state, output_path, version)?;
+    save_vmstate(microvm_state, output_path)?;
     Ok(())
 }
 

src/snapshot-editor/src/utils.rs

@@ -5,7 +5,7 @@ use std::fs::{File, OpenOptions};
 use std::path::PathBuf;
 
 use semver::Version;
-use vmm::persist::MicrovmState;
+use vmm::persist::{MicrovmState, SNAPSHOT_VERSION};
 use vmm::snapshot::Snapshot;
 use vmm::utils::u64_to_usize;
 
@@ -35,18 +35,14 @@ pub fn open_vmstate(snapshot_path: &PathBuf) -> Result<(MicrovmState, Version),
 
 // This method is used only in aarch64 code so far
 #[allow(unused)]
-pub fn save_vmstate(
-    microvm_state: MicrovmState,
-    output_path: &PathBuf,
-    version: Version,
-) -> Result<(), UtilsError> {
+pub fn save_vmstate(microvm_state: MicrovmState, output_path: &PathBuf) -> Result<(), UtilsError> {
     let mut output_file = OpenOptions::new()
         .create(true)
         .write(true)
         .truncate(true)
         .open(output_path)
         .map_err(UtilsError::OutputFileOpen)?;
-    let mut snapshot = Snapshot::new(version);
+    let mut snapshot = Snapshot::new(SNAPSHOT_VERSION);
     snapshot
         .save(&mut output_file, &microvm_state)
         .map_err(UtilsError::VmStateSave)?;