syntax = "proto3";

package hcsshim.controller.vm.save.v1;

option go_package = "github.com/Microsoft/hcsshim/internal/controller/vm/save;save";

import "google/protobuf/any.proto";

// Payload is the migration payload owned by the VM controller. It is the
// top-level message wrapped in an [anypb.Any] when handed off between source
// and destination shims. The SCSI sub-controller is carried as an opaque
// [anypb.Any] so it fully owns its own schema and versioning.
message Payload {
  // schema_version is bumped whenever a field's semantics change. The
  // destination MUST reject states whose version it does not recognise.
  uint32 schema_version = 1;

  // vm_id is the HCS identifier of the running VM.
  string vm_id = 2;

  // sandbox_options is the original set of options the VM was built from,
  // so the destination can recreate an equivalent VM.
  SandboxOptions sandbox_options = 3;

  // scsi is the SCSI sub-controller's [anypb.Any] envelope (attached
  // disks, mounts and outstanding reservations).
  google.protobuf.Any scsi = 4;

  // gcs_next_port is the next free vsock port in the GCS port allocator.
  // The destination seeds its allocator with this value so newly opened
  // IO channels do not collide with per-process ports restored elsewhere.
  uint32 gcs_next_port = 5;

  // compat_info is the opaque, host-emitted compatibility blob describing
  // the source VM's compatibility surface. The destination passes it back
  // to HCS when starting the target VM so the platform can verify that the
  // two VMs can interchange live-migration state.
  bytes compat_info = 6;

  // hcs_document is the JSON-encoded HCS [hcsschema.ComputeSystem] document
  // that was used to create the source VM. The destination reuses this
  // document verbatim (with [hcsschema.VirtualMachine.MigrationOptions]
  // set) when creating the destination VM, ensuring the two VMs have
  // identical hardware topology required for live-migration compatibility.
  bytes hcs_document = 7;

  // bridge_next_id is the source bridge's next request-id. The destination
  // seeds its bridge above this so newly issued ids cannot collide with
  // requests the guest still has outstanding from the source.
  int64 bridge_next_id = 8;
}

// SandboxOptions is the set of VM-creation options preserved verbatim so the
// destination can build an equivalent VM.
message SandboxOptions {
  // no_writable_file_shares disallows read/write file shares into the guest.
  bool no_writable_file_shares = 1;

  // enable_scratch_encryption enables dm-crypt on the scratch disk.
  bool enable_scratch_encryption = 2;

  // policy_based_routing enables policy-based routing in the guest network
  // stack.
  bool policy_based_routing = 3;

  // architecture is the guest CPU architecture (e.g. "amd64", "arm64").
  string architecture = 4;

  // fully_physically_backed forces all guest memory to be backed by physical
  // memory (disables hot-add) and, as a side effect, disables VPMEM.
  bool fully_physically_backed = 5;
}