text: #ifndef QEMU_HW_SCSI_H
  #define QEMU_HW_SCSI_H
  
  #include "hw/qdev.h"
  #include "qemu/typedefs.h"
  #include "hw/block/block.h"
  #include "sysemu/sysemu.h"
  #include "qemu/notify.h"
  
  #define MAX_SCSI_DEVS	255
  
  #define SCSI_CMD_BUF_SIZE     16
  #define SCSI_SENSE_LEN      18
  #define SCSI_INQUIRY_LEN    36
  
  typedef struct SCSIBus SCSIBus;
  typedef struct SCSIBusInfo SCSIBusInfo;
  typedef struct SCSICommand SCSICommand;
  typedef struct SCSIDevice SCSIDevice;
  typedef struct SCSIRequest SCSIRequest;
  typedef struct SCSIReqOps SCSIReqOps;
  
  enum SCSIXferMode {
      SCSI_XFER_NONE,      /*  TEST_UNIT_READY, ...            */
      SCSI_XFER_FROM_DEV,  /*  READ, INQUIRY, MODE_SENSE, ...  */
      SCSI_XFER_TO_DEV,    /*  WRITE, MODE_SELECT, ...         */
  };
  
  typedef struct SCSISense {
      uint8_t key;
      uint8_t asc;
      uint8_t ascq;
  } SCSISense;
  
  #define SCSI_SENSE_BUF_SIZE_OLD 96
  #define SCSI_SENSE_BUF_SIZE 252
  
  struct SCSICommand {
      uint8_t buf[SCSI_CMD_BUF_SIZE];
      int len;
      size_t xfer;
      uint64_t lba;
      enum SCSIXferMode mode;
  };
  
  struct SCSIRequest {
      SCSIBus           *bus;
      SCSIDevice        *dev;
      const SCSIReqOps  *ops;
      uint32_t          refcount;
      uint32_t          tag;
      uint32_t          lun;
      uint32_t          status;
      void              *hba_private;
      size_t            resid;
      SCSICommand       cmd;
      NotifierList      cancel_notifiers;
  
      /* Note:
       * - fields before sense are initialized by scsi_req_alloc;
       * - sense[] is uninitialized;
       * - fields after sense are memset to 0 by scsi_req_alloc.
       * */
  
      uint8_t           sense[SCSI_SENSE_BUF_SIZE];
      uint32_t          sense_len;
      bool              enqueued;
      bool              io_canceled;
      bool              retry;
      bool              dma_started;
      BlockAIOCB        *aiocb;
      QEMUSGList        *sg;
      QTAILQ_ENTRY(SCSIRequest) next;
  };
  
  #define TYPE_SCSI_DEVICE "scsi-device"
  #define SCSI_DEVICE(obj) \
       OBJECT_CHECK(SCSIDevice, (obj), TYPE_SCSI_DEVICE)
  #define SCSI_DEVICE_CLASS(klass) \
       OBJECT_CLASS_CHECK(SCSIDeviceClass, (klass), TYPE_SCSI_DEVICE)
  #define SCSI_DEVICE_GET_CLASS(obj) \
       OBJECT_GET_CLASS(SCSIDeviceClass, (obj), TYPE_SCSI_DEVICE)
  
  typedef struct SCSIDeviceClass {
      DeviceClass parent_class;
      void (*realize)(SCSIDevice *dev, Error **errp);
      int (*parse_cdb)(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
                       void *hba_private);
      SCSIRequest *(*alloc_req)(SCSIDevice *s, uint32_t tag, uint32_t lun,
                                uint8_t *buf, void *hba_private);
      void (*unit_attention_reported)(SCSIDevice *s);
  } SCSIDeviceClass;
  
  struct SCSIDevice
  {
      DeviceState qdev;
      VMChangeStateEntry *vmsentry;
      QEMUBH *bh;
      uint32_t id;
      BlockConf conf;
      SCSISense unit_attention;
      bool sense_is_ua;
      uint8_t sense[SCSI_SENSE_BUF_SIZE];
      uint32_t sense_len;
      QTAILQ_HEAD(, SCSIRequest) requests;
      uint32_t channel;
      uint32_t lun;
      int blocksize;
      int type;
      uint64_t max_lba;
  };
  
  extern const VMStateDescription vmstate_scsi_device;
  
  #define VMSTATE_SCSI_DEVICE(_field, _state) {                        \
      .name       = (stringify(_field)),                               \
      .size       = sizeof(SCSIDevice),                                \
      .vmsd       = &vmstate_scsi_device,                              \
      .flags      = VMS_STRUCT,                                        \
      .offset     = vmstate_offset_value(_state, _field, SCSIDevice),  \
  }
  
  /* cdrom.c */
  int cdrom_read_toc(int nb_sectors, uint8_t *buf, int msf, int start_track);
  int cdrom_read_toc_raw(int nb_sectors, uint8_t *buf, int msf, int session_num);
  
  /* scsi-bus.c */
  struct SCSIReqOps {
      size_t size;
      void (*free_req)(SCSIRequest *req);
      int32_t (*send_command)(SCSIRequest *req, uint8_t *buf);
      void (*read_data)(SCSIRequest *req);
      void (*write_data)(SCSIRequest *req);
      uint8_t *(*get_buf)(SCSIRequest *req);
  
      void (*save_request)(QEMUFile *f, SCSIRequest *req);
      void (*load_request)(QEMUFile *f, SCSIRequest *req);
  };
  
  struct SCSIBusInfo {
      int tcq;
      int max_channel, max_target, max_lun;
      int (*parse_cdb)(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
                       void *hba_private);
      void (*transfer_data)(SCSIRequest *req, uint32_t arg);
      void (*complete)(SCSIRequest *req, uint32_t arg, size_t resid);
      void (*cancel)(SCSIRequest *req);
      void (*change)(SCSIBus *bus, SCSIDevice *dev, SCSISense sense);
      QEMUSGList *(*get_sg_list)(SCSIRequest *req);
  
      void (*save_request)(QEMUFile *f, SCSIRequest *req);
      void *(*load_request)(QEMUFile *f, SCSIRequest *req);
      void (*free_request)(SCSIBus *bus, void *priv);
  };
  
  #define TYPE_SCSI_BUS "SCSI"
  #define SCSI_BUS(obj) OBJECT_CHECK(SCSIBus, (obj), TYPE_SCSI_BUS)
  
  struct SCSIBus {
      BusState qbus;
      int busnr;
  
      SCSISense unit_attention;
      const SCSIBusInfo *info;
  };
  
  void scsi_bus_new(SCSIBus *bus, size_t bus_size, DeviceState *host,
                    const SCSIBusInfo *info, const char *bus_name);
  
  static inline SCSIBus *scsi_bus_from_device(SCSIDevice *d)
  {
      return DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
  }
  
  SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
                                        int unit, bool removable, int bootindex,
                                        const char *serial, Error **errp);
  void scsi_bus_legacy_handle_cmdline(SCSIBus *bus, Error **errp);
  
  /*
   * Predefined sense codes
   */
  
  /* No sense data available */
  extern const struct SCSISense sense_code_NO_SENSE;
  /* LUN not ready, Manual intervention required */
  extern const struct SCSISense sense_code_LUN_NOT_READY;
  /* LUN not ready, Medium not present */
  extern const struct SCSISense sense_code_NO_MEDIUM;
  /* LUN not ready, medium removal prevented */
  extern const struct SCSISense sense_code_NOT_READY_REMOVAL_PREVENTED;
  /* Hardware error, internal target failure */
  extern const struct SCSISense sense_code_TARGET_FAILURE;
  /* Illegal request, invalid command operation code */
  extern const struct SCSISense sense_code_INVALID_OPCODE;
  /* Illegal request, LBA out of range */
  extern const struct SCSISense sense_code_LBA_OUT_OF_RANGE;
  /* Illegal request, Invalid field in CDB */
  extern const struct SCSISense sense_code_INVALID_FIELD;
  /* Illegal request, Invalid field in parameter list */
  extern const struct SCSISense sense_code_INVALID_PARAM;
  /* Illegal request, Parameter list length error */
  extern const struct SCSISense sense_code_INVALID_PARAM_LEN;
  /* Illegal request, LUN not supported */
  extern const struct SCSISense sense_code_LUN_NOT_SUPPORTED;
  /* Illegal request, Saving parameters not supported */
  extern const struct SCSISense sense_code_SAVING_PARAMS_NOT_SUPPORTED;
  /* Illegal request, Incompatible format */
  extern const struct SCSISense sense_code_INCOMPATIBLE_FORMAT;
  /* Illegal request, medium removal prevented */
  extern const struct SCSISense sense_code_ILLEGAL_REQ_REMOVAL_PREVENTED;
  /* Illegal request, Invalid Transfer Tag */
  extern const struct SCSISense sense_code_INVALID_TAG;
  /* Command aborted, I/O process terminated */
  extern const struct SCSISense sense_code_IO_ERROR;
  /* Command aborted, I_T Nexus loss occurred */
  extern const struct SCSISense sense_code_I_T_NEXUS_LOSS;
  /* Command aborted, Logical Unit failure */
  extern const struct SCSISense sense_code_LUN_FAILURE;
  /* Command aborted, Overlapped Commands Attempted */
  extern const struct SCSISense sense_code_OVERLAPPED_COMMANDS;
  /* LUN not ready, Capacity data has changed */
  extern const struct SCSISense sense_code_CAPACITY_CHANGED;
  /* LUN not ready, Medium not present */
  extern const struct SCSISense sense_code_UNIT_ATTENTION_NO_MEDIUM;
  /* Unit attention, Power on, reset or bus device reset occurred */
  extern const struct SCSISense sense_code_RESET;
  /* Unit attention, Medium may have changed*/
  extern const struct SCSISense sense_code_MEDIUM_CHANGED;
  /* Unit attention, Reported LUNs data has changed */
  extern const struct SCSISense sense_code_REPORTED_LUNS_CHANGED;
  /* Unit attention, Device internal reset */
  extern const struct SCSISense sense_code_DEVICE_INTERNAL_RESET;
  /* Data Protection, Write Protected */
  extern const struct SCSISense sense_code_WRITE_PROTECTED;
  /* Data Protection, Space Allocation Failed Write Protect */
  extern const struct SCSISense sense_code_SPACE_ALLOC_FAILED;
  
  #define SENSE_CODE(x) sense_code_ ## x
  
  uint32_t scsi_data_cdb_xfer(uint8_t *buf);
  uint32_t scsi_cdb_xfer(uint8_t *buf);
  int scsi_cdb_length(uint8_t *buf);
  int scsi_sense_valid(SCSISense sense);
  int scsi_build_sense(uint8_t *in_buf, int in_len,
                       uint8_t *buf, int len, bool fixed);
  
  SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
                              uint32_t tag, uint32_t lun, void *hba_private);
  SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
                            uint8_t *buf, void *hba_private);
  int32_t scsi_req_enqueue(SCSIRequest *req);
  void scsi_req_free(SCSIRequest *req);
  SCSIRequest *scsi_req_ref(SCSIRequest *req);
  void scsi_req_unref(SCSIRequest *req);
  
  int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
                         void *hba_private);
  int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf);
  void scsi_req_build_sense(SCSIRequest *req, SCSISense sense);
  void scsi_req_print(SCSIRequest *req);
  void scsi_req_continue(SCSIRequest *req);
  void scsi_req_data(SCSIRequest *req, int len);
  void scsi_req_complete(SCSIRequest *req, int status);
  uint8_t *scsi_req_get_buf(SCSIRequest *req);
  int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len);
  void scsi_req_cancel_complete(SCSIRequest *req);
  void scsi_req_cancel(SCSIRequest *req);
  void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier);
  void scsi_req_retry(SCSIRequest *req);
  void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense);
  void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense);
  void scsi_device_report_change(SCSIDevice *dev, SCSISense sense);
  void scsi_device_unit_attention_reported(SCSIDevice *dev);
  int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed);
  SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int target, int lun);
  
  /* scsi-generic.c. */
  extern const SCSIReqOps scsi_generic_req_ops;
  
  #endif
  