syntax = "proto3";

import "nvme.proto";
import "virtio_blk.proto";
import "nvmf_tcp.proto";
import "nvmf.proto";

// This file provides the generic definitions for the Storage Management Agent
// gRPC calls.  All of the methods are supposed to be idempotent.  Errors are
// reported as standard gRPC status codes.

package sma;

option go_package = "spdk.io/sma";

// Enumeration defining types of devices
enum DeviceType {
  DEVICE_TYPE_INVALID = 0;
  DEVICE_TYPE_NVME = 1;
  DEVICE_TYPE_VIRTIO_BLK = 2;
  DEVICE_TYPE_NVMF_TCP = 3;
}

// Volume's crypto parameters
message VolumeCryptoParameters {
  // Key to be used for encryption
  bytes key = 1;
  // Second key (only required by some ciphers)
  bytes key2 = 2;
  enum Cipher {
    AES_CBC = 0;
    AES_XTS = 1;
  }
  // Cipher to use
  Cipher cipher = 3;
}

// Parameters describing a volume
message VolumeParameters {
  // Volume GUID/UUID
  bytes volume_id = 1;
  oneof connection_params {
    // NVMeoF volume
    nvmf.VolumeConnectionParameters nvmf = 2;
  }
  // Crypto parameters (optional)
  VolumeCryptoParameters crypto = 3;
}

// Create device request
message CreateDeviceRequest {
  // Volume to immediately attach to the created device.  This field may be
  // optional for some device types (e.g. NVMe), while it may be required for
  // others (e.g. virtio-blk).
  VolumeParameters volume = 1;
  // Device-specific parameters
  oneof params {
    // NVMe parameters
    nvme.DeviceParameters nvme = 2;
    // Virtio-blk parameters
    virtio_blk.DeviceParameters virtio_blk = 3;
    // NVMe/TCP parameters
    nvmf_tcp.DeviceParameters nvmf_tcp = 4;
  }
}

// Create device response
message CreateDeviceResponse {
  // Device handle that can uniquely identify a device within an instance of
  // Storage Management Agent
  string handle = 1;
}

// Delete device request
message DeleteDeviceRequest {
  // Device handle
  string handle = 1;
}

// Delete device response
message DeleteDeviceResponse {}

// Attach volume request
message AttachVolumeRequest {
  // Volume parameters
  VolumeParameters volume = 1;
  // Device handle
  string device_handle = 2;
}

// Attach volume response
message AttachVolumeResponse {}

// Detach volume request
message DetachVolumeRequest {
  // Volume GUID/UUID
  bytes volume_id = 1;
  // Device handle
  string device_handle = 2;
}

// Detach volume response
message DetachVolumeResponse {}

// QoS limit values.  0 means unlimited, while UINT64_MAX means to leave the
// current limit value unchanged.  If one of the limits isn't supported by a
// given device/volume, it must be set to 0.
message QosLimit {
  // Read kIOPS
  uint64 rd_iops = 1;
  // Write kIOPS
  uint64 wr_iops = 2;
  // Read/write kIOPS
  uint64 rw_iops = 3;
  // Read bandwidth (MB/s)
  uint64 rd_bandwidth = 4;
  // Write bandwidth (MB/s)
  uint64 wr_bandwidth = 5;
  // Read/write bandwidth (MB/s)
  uint64 rw_bandwidth = 6;
}

// SetQos request
message SetQosRequest {
  // Device handle
  string device_handle = 1;
  // GUID/UUID of a volume to configure QoS on.  If this parameter is omitted,
  // the QoS will be set up on the whole device (all volumes attached to that
  // device will share QoS settings).  Some device types might only support
  // configuring QoS on per-device (volume_id must be empty) or per-volume level
  // (volume_id cannot be empty).  This information can be obtained by sending a
  // GetQosCapabilities request.
  bytes volume_id = 2;
  // Maximum allowed IOPS/bandwidth
  QosLimit maximum = 3;
}

// SetQos response
message SetQosResponse {}

// Get QoS capabilities request
message GetQosCapabilitiesRequest {
  // Type of a device to query for QoS capabilities
  DeviceType device_type = 1;
}

// Get QoS capabilities response
message GetQosCapabilitiesResponse {
  message QosCapabilities {
    // Read IOPS
    bool rd_iops = 1;
    // Write IOPS
    bool wr_iops = 2;
    // Read/write IOPS
    bool rw_iops = 3;
    // Read bandwidth
    bool rd_bandwidth = 4;
    // Write bandwidth
    bool wr_bandwidth = 5;
    // Read/write bandwidth
    bool rw_bandwidth = 6;
  }
  // Device level maximum QoS limits
  QosCapabilities max_device_caps = 1;
  // Volume level maximum QoS limits
  QosCapabilities max_volume_caps = 2;
};

// Storage Management Agent gRPC service definition
service StorageManagementAgent {
  // Creates a new device.  A device is an entity that can be used to expose
  // volumes (e.g. an NVMeoF subsystem).
  rpc CreateDevice (CreateDeviceRequest)
    returns (CreateDeviceResponse) {}
  // Deletes a device.  It is only allowed to delete a device with volumes still
  // attached if that device doesn't support attaching volumes through
  // AttachVolume (e.g. virtio-blk).   In other cases, it is forbidden and
  // FAILED_PRECONDITION status will be returned.
  rpc DeleteDevice (DeleteDeviceRequest)
    returns (DeleteDeviceResponse) {}
  // Attaches a volume to a specified device making it available through that
  // device (e.g. for NVMeoF this results in adding a namespace to an NVMeoF
  // subsystem).  The type of volume doesn't need to match the type of device
  // (e.g. it's perfectly fine to attach an NVMe/TCP volume to a virtio-blk
  // device).
  rpc AttachVolume (AttachVolumeRequest)
    returns (AttachVolumeResponse) {}
  // Detaches a volume from a device
  rpc DetachVolume (DetachVolumeRequest)
    returns (DetachVolumeResponse) {}
  // Configures QoS on a device/volume
  rpc SetQos (SetQosRequest)
    returns (SetQosResponse) {}
  // Returns QoS capabilities of a given device type
  rpc GetQosCapabilities (GetQosCapabilitiesRequest)
    returns (GetQosCapabilitiesResponse) {}
}