code: func (d *Device) entReqIovCnt(off int) uint32 {
  	return *(*uint32)(unsafe.Pointer(&d.mmap[off+offReqIovCnt]))
  }
docs: /*
  #define TCMU_SENSE_BUFFERSIZE 96
  
  struct tcmu_cmd_entry {
  	  struct tcmu_cmd_entry_hdr hdr;
  
  		union {
  			struct {
  				uint32_t iov_cnt; 0
  				uint32_t iov_bidi_cnt; 4
  				uint32_t iov_dif_cnt; 8
  				uint64_t cdb_off; 12
  				uint64_t __pad1; 20
  				uint64_t __pad2; 28
  				struct iovec iov[0];
  
  			} req;
  			struct {
  				uint8_t scsi_status;
  				uint8_t __pad1;
  				uint16_t __pad2;
  				uint32_t __pad3;
  				char sense_buffer[TCMU_SENSE_BUFFERSIZE];
  
  			} rsp;
  		};
  } __packed;
  */