virtio-devices: Version state structures

Version the state for device state for the virtio devices.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

virtio-devices/src/watchdog.rs

@@ -22,7 +22,10 @@ use std::sync::atomic::AtomicBool;
 use std::sync::{Arc, Barrier, Mutex};
 use std::thread;
 use std::time::Instant;
+use versionize::{VersionMap, Versionize, VersionizeResult};
+use versionize_derive::Versionize;
 use vm_memory::{Bytes, GuestAddressSpace, GuestMemoryAtomic, GuestMemoryMmap};
+use vm_migration::VersionMapped;
 use vm_migration::{Migratable, MigratableError, Pausable, Snapshot, Snapshottable, Transportable};
 use vmm_sys_util::eventfd::EventFd;
 
@@ -164,13 +167,15 @@ pub struct Watchdog {
     timer: File,
 }
 
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Versionize)]
 pub struct WatchdogState {
     pub avail_features: u64,
     pub acked_features: u64,
     pub enabled: bool,
 }
 
+impl VersionMapped for WatchdogState {}
+
 impl Watchdog {
     /// Create a new virtio watchdog device that will reboot VM if the guest hangs
     pub fn new(
@@ -392,11 +397,11 @@ impl Snapshottable for Watchdog {
     }
 
     fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
-        Snapshot::new_from_state(&self.id, &self.state())
+        Snapshot::new_from_versioned_state(&self.id, &self.state())
     }
 
     fn restore(&mut self, snapshot: Snapshot) -> std::result::Result<(), MigratableError> {
-        self.set_state(&snapshot.to_state(&self.id)?);
+        self.set_state(&snapshot.to_versioned_state(&self.id)?);
         Ok(())
     }
 }