vmm: Add "prefault" option when restoring

Now that the restore path uses RestoreConfig structure, we add a new
parameter called "prefault" to it. This will give the user the ability
to populate the pages corresponding to the mapped regions backed by the
snapshotted memory files.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

vmm/src/lib.rs

@@ -331,6 +331,7 @@ impl Vmm {
             reset_evt,
             self.vmm_path.clone(),
             source_url,
+            restore_cfg.prefault,
         )?;
         self.vm = Some(vm);