vm-migration: Make snapshot() mutable

There will be some cases where the implementation of the snapshot()
function from the Snapshottable trait will require to modify some
internal data, therefore we make this possible by updating the trait
definition with snapshot(&mut self).

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

devices/src/gic.rs

@@ -70,7 +70,7 @@ impl Snapshottable for Gic {
         GIC_SNAPSHOT_ID.to_string()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         unimplemented!();
     }
 

devices/src/ioapic.rs

@@ -405,7 +405,7 @@ impl Snapshottable for Ioapic {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

devices/src/legacy/serial.rs

@@ -289,7 +289,7 @@ impl Snapshottable for Serial {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

pci/src/configuration.rs

@@ -889,7 +889,7 @@ impl Snapshottable for PciConfiguration {
         String::from("pci_configuration")
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

pci/src/msix.rs

@@ -437,7 +437,7 @@ impl Snapshottable for MsixConfig {
         String::from("msix_config")
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/block.rs

@@ -620,7 +620,7 @@ impl<T: 'static + DiskFile + Send> Snapshottable for Block<T> {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/block_io_uring.rs

@@ -670,7 +670,7 @@ impl Snapshottable for BlockIoUring {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/console.rs

@@ -552,7 +552,7 @@ impl Snapshottable for Console {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/iommu.rs

@@ -1016,7 +1016,7 @@ impl Snapshottable for Iommu {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/net.rs

@@ -565,7 +565,7 @@ impl Snapshottable for Net {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/pmem.rs

@@ -524,7 +524,7 @@ impl Snapshottable for Pmem {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/rng.rs

@@ -348,7 +348,7 @@ impl Snapshottable for Rng {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/transport/mmio.rs

@@ -462,7 +462,7 @@ impl Snapshottable for MmioDevice {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/transport/pci_common_config.rs

@@ -290,7 +290,7 @@ impl Snapshottable for VirtioPciCommonConfig {
         String::from("virtio_pci_common_config")
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/transport/pci_device.rs

@@ -1040,7 +1040,7 @@ impl Snapshottable for VirtioPciDevice {
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

virtio-devices/src/vsock/device.rs

@@ -535,7 +535,7 @@ where
         self.id.clone()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot =
             serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
 

vm-migration/src/lib.rs

@@ -111,7 +111,7 @@ pub trait Snapshottable: Pausable {
     }
 
     /// Take a component snapshot.
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         Ok(Snapshot::new(""))
     }
 

vmm/src/cpu.rs

@@ -400,7 +400,7 @@ impl Snapshottable for Vcpu {
         VCPU_SNAPSHOT_ID.to_string()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let snapshot = serde_json::to_vec(&self.saved_state)
             .map_err(|e| MigratableError::Snapshot(e.into()))?;
 
@@ -1368,7 +1368,7 @@ impl Snapshottable for CpuManager {
         CPU_MANAGER_SNAPSHOT_ID.to_string()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let mut cpu_manager_snapshot = Snapshot::new(CPU_MANAGER_SNAPSHOT_ID);
 
         // The CpuManager snapshot is a collection of all vCPUs snapshots.

vmm/src/device_manager.rs

@@ -3626,7 +3626,7 @@ impl Snapshottable for DeviceManager {
         DEVICE_MANAGER_SNAPSHOT_ID.to_string()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let mut snapshot = Snapshot::new(DEVICE_MANAGER_SNAPSHOT_ID);
 
         // We aggregate all devices snapshots.

vmm/src/memory_manager.rs

@@ -1526,7 +1526,7 @@ impl Snapshottable for MemoryManager {
         MEMORY_MANAGER_SNAPSHOT_ID.to_string()
     }
 
-    fn snapshot(&self) -> result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> result::Result<Snapshot, MigratableError> {
         if self.use_zones {
             return Err(MigratableError::Snapshot(anyhow!(
                 "Not allowed to snapshot guest memory when backed with user \

vmm/src/vm.rs

@@ -1267,7 +1267,7 @@ impl Snapshottable for Vm {
         VM_SNAPSHOT_ID.to_string()
     }
 
-    fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
+    fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
         let current_state = self.get_state().unwrap();
         if current_state != VmState::Paused {
             return Err(MigratableError::Snapshot(anyhow!(