Add container_snapshot_path to load snapshot request

client/swagger.yaml

@@ -1188,6 +1188,7 @@ definitions:
       the two `mem_*` fields must be present in the body of the request.
     required:
       - snapshot_path
+      - container_snapshot_path
     properties:
       enable_diff_snapshots:
         type: boolean
@@ -1212,6 +1213,10 @@ definitions:
         type: boolean
         description:
           When set to true, the vm is also resumed if the snapshot load is successful.
+      container_snapshot_path:
+        type: string
+        description:
+          Path to the disk device backing the container snapshot.
 
   TokenBucket:
     type: object

handlers.go

@@ -321,7 +321,10 @@ var loadSnapshotHandlerList = HandlerList{}.Append(
 	CreateLogFilesHandler,
 	BootstrapLoggingHandler,
 	LoadSnapshotHandler,
-	AddVsocksHandler,
+	// According to the firecracker OpenAPI specification, creating vsock devices is only a pre-boot request, so adding
+	// vsocks after loading a snapshot fails. It also seems redundant, since the VM loaded from a snapshot restores
+	// vsocks anyways (firecracker-microvm/firecracker-go-sdk#506).
+	// AddVsocksHandler,
 )
 
 var defaultValidationHandlerList = HandlerList{}.Append(

machine.go

@@ -172,7 +172,7 @@ type Config struct {
 }
 
 func (cfg *Config) hasSnapshot() bool {
-	return cfg.Snapshot.GetMemBackendPath() != "" || cfg.Snapshot.SnapshotPath != ""
+	return cfg.Snapshot.GetMemBackendPath() != "" || cfg.Snapshot.SnapshotPath != "" || cfg.Snapshot.ContainerSnapshotPath != ""
 }
 
 // Validate will ensure that the required fields are set and that
@@ -243,6 +243,10 @@ func (cfg *Config) ValidateLoadSnapshot() error {
 		return err
 	}
 
+	if _, err := os.Stat(cfg.Snapshot.ContainerSnapshotPath); err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -1171,11 +1175,12 @@ func (m *Machine) CreateSnapshot(ctx context.Context, memFilePath, snapshotPath
 // loadSnapshot loads a snapshot of the VM
 func (m *Machine) loadSnapshot(ctx context.Context, snapshot *SnapshotConfig) error {
 	snapshotParams := &models.SnapshotLoadParams{
-		MemFilePath:         snapshot.MemFilePath,
-		MemBackend:          snapshot.MemBackend,
-		SnapshotPath:        &snapshot.SnapshotPath,
-		EnableDiffSnapshots: snapshot.EnableDiffSnapshots,
-		ResumeVM:            snapshot.ResumeVM,
+		MemFilePath:           snapshot.MemFilePath,
+		MemBackend:            snapshot.MemBackend,
+		SnapshotPath:          &snapshot.SnapshotPath,
+		EnableDiffSnapshots:   snapshot.EnableDiffSnapshots,
+		ResumeVM:              snapshot.ResumeVM,
+		ContainerSnapshotPath: &snapshot.ContainerSnapshotPath,
 	}
 
 	if _, err := m.client.LoadSnapshot(ctx, snapshotParams); err != nil {

opts.go

@@ -62,10 +62,11 @@ type WithSnapshotOpt func(*SnapshotConfig)
 //	WithSnapshot(
 //	  "", snapshotPath,
 //	  WithMemoryBackend(models.MemoryBackendBackendTypeUffd, "uffd.sock"))
-func WithSnapshot(memFilePath, snapshotPath string, opts ...WithSnapshotOpt) Opt {
+func WithSnapshot(memFilePath, snapshotPath, ContainerSnapshotPath string, opts ...WithSnapshotOpt) Opt {
 	return func(m *Machine) {
 		m.Cfg.Snapshot.MemFilePath = memFilePath
 		m.Cfg.Snapshot.SnapshotPath = snapshotPath
+		m.Cfg.Snapshot.ContainerSnapshotPath = ContainerSnapshotPath
 
 		for _, opt := range opts {
 			opt(&m.Cfg.Snapshot)

snapshot.go

@@ -16,11 +16,12 @@ package firecracker
 import "github.com/firecracker-microvm/firecracker-go-sdk/client/models"
 
 type SnapshotConfig struct {
-	MemFilePath         string
-	MemBackend          *models.MemoryBackend
-	SnapshotPath        string
-	EnableDiffSnapshots bool
-	ResumeVM            bool
+	MemFilePath           string
+	MemBackend            *models.MemoryBackend
+	SnapshotPath          string
+	EnableDiffSnapshots   bool
+	ResumeVM              bool
+	ContainerSnapshotPath string
 }
 
 // GetMemBackendPath returns the effective memory backend path. If MemBackend