xref: /openbmc/qemu/scsi/utils.c (revision ba632924)
1 /*
2  *  SCSI helpers
3  *
4  *  Copyright 2017 Red Hat, Inc.
5  *
6  *  Authors:
7  *   Fam Zheng <famz@redhat.com>
8  *   Paolo Bonzini <pbonzini@redhat.com>
9  *
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms of the GNU General Public License as published by the Free
12  * Software Foundation; either version 2 of the License, or (at your option)
13  * any later version.
14  */
15 
16 #include "qemu/osdep.h"
17 #include "scsi/constants.h"
18 #include "scsi/utils.h"
19 #include "qemu/bswap.h"
20 
21 uint32_t scsi_data_cdb_xfer(uint8_t *buf)
22 {
23     if ((buf[0] >> 5) == 0 && buf[4] == 0) {
24         return 256;
25     } else {
26         return scsi_cdb_xfer(buf);
27     }
28 }
29 
30 uint32_t scsi_cdb_xfer(uint8_t *buf)
31 {
32     switch (buf[0] >> 5) {
33     case 0:
34         return buf[4];
35         break;
36     case 1:
37     case 2:
38         return lduw_be_p(&buf[7]);
39         break;
40     case 4:
41         return ldl_be_p(&buf[10]) & 0xffffffffULL;
42         break;
43     case 5:
44         return ldl_be_p(&buf[6]) & 0xffffffffULL;
45         break;
46     default:
47         return -1;
48     }
49 }
50 
51 uint64_t scsi_cmd_lba(SCSICommand *cmd)
52 {
53     uint8_t *buf = cmd->buf;
54     uint64_t lba;
55 
56     switch (buf[0] >> 5) {
57     case 0:
58         lba = ldl_be_p(&buf[0]) & 0x1fffff;
59         break;
60     case 1:
61     case 2:
62     case 5:
63         lba = ldl_be_p(&buf[2]) & 0xffffffffULL;
64         break;
65     case 4:
66         lba = ldq_be_p(&buf[2]);
67         break;
68     default:
69         lba = -1;
70 
71     }
72     return lba;
73 }
74 
75 int scsi_cdb_length(uint8_t *buf)
76 {
77     int cdb_len;
78 
79     switch (buf[0] >> 5) {
80     case 0:
81         cdb_len = 6;
82         break;
83     case 1:
84     case 2:
85         cdb_len = 10;
86         break;
87     case 4:
88         cdb_len = 16;
89         break;
90     case 5:
91         cdb_len = 12;
92         break;
93     default:
94         cdb_len = -1;
95     }
96     return cdb_len;
97 }
98 
99 SCSISense scsi_parse_sense_buf(const uint8_t *in_buf, int in_len)
100 {
101     bool fixed_in;
102     SCSISense sense;
103 
104     assert(in_len > 0);
105     fixed_in = (in_buf[0] & 2) == 0;
106     if (fixed_in) {
107         if (in_len < 14) {
108             return SENSE_CODE(IO_ERROR);
109         }
110         sense.key = in_buf[2];
111         sense.asc = in_buf[12];
112         sense.ascq = in_buf[13];
113     } else {
114         if (in_len < 4) {
115             return SENSE_CODE(IO_ERROR);
116         }
117         sense.key = in_buf[1];
118         sense.asc = in_buf[2];
119         sense.ascq = in_buf[3];
120     }
121 
122     return sense;
123 }
124 
125 int scsi_build_sense_buf(uint8_t *out_buf, size_t size, SCSISense sense,
126                          bool fixed_sense)
127 {
128     int len;
129     uint8_t buf[SCSI_SENSE_LEN] = { 0 };
130 
131     if (fixed_sense) {
132         buf[0] = 0x70;
133         buf[2] = sense.key;
134         buf[7] = 10;
135         buf[12] = sense.asc;
136         buf[13] = sense.ascq;
137         len = 18;
138     } else {
139         buf[0] = 0x72;
140         buf[1] = sense.key;
141         buf[2] = sense.asc;
142         buf[3] = sense.ascq;
143         len = 8;
144     }
145     len = MIN(len, size);
146     memcpy(out_buf, buf, len);
147     return len;
148 }
149 
150 int scsi_build_sense(uint8_t *buf, SCSISense sense)
151 {
152     return scsi_build_sense_buf(buf, SCSI_SENSE_LEN, sense, true);
153 }
154 
155 /*
156  * Predefined sense codes
157  */
158 
159 /* No sense data available */
160 const struct SCSISense sense_code_NO_SENSE = {
161     .key = NO_SENSE , .asc = 0x00 , .ascq = 0x00
162 };
163 
164 /* LUN not ready, Manual intervention required */
165 const struct SCSISense sense_code_LUN_NOT_READY = {
166     .key = NOT_READY, .asc = 0x04, .ascq = 0x03
167 };
168 
169 /* LUN not ready, Medium not present */
170 const struct SCSISense sense_code_NO_MEDIUM = {
171     .key = NOT_READY, .asc = 0x3a, .ascq = 0x00
172 };
173 
174 /* LUN not ready, medium removal prevented */
175 const struct SCSISense sense_code_NOT_READY_REMOVAL_PREVENTED = {
176     .key = NOT_READY, .asc = 0x53, .ascq = 0x02
177 };
178 
179 /* Hardware error, internal target failure */
180 const struct SCSISense sense_code_TARGET_FAILURE = {
181     .key = HARDWARE_ERROR, .asc = 0x44, .ascq = 0x00
182 };
183 
184 /* Illegal request, invalid command operation code */
185 const struct SCSISense sense_code_INVALID_OPCODE = {
186     .key = ILLEGAL_REQUEST, .asc = 0x20, .ascq = 0x00
187 };
188 
189 /* Illegal request, LBA out of range */
190 const struct SCSISense sense_code_LBA_OUT_OF_RANGE = {
191     .key = ILLEGAL_REQUEST, .asc = 0x21, .ascq = 0x00
192 };
193 
194 /* Illegal request, Invalid field in CDB */
195 const struct SCSISense sense_code_INVALID_FIELD = {
196     .key = ILLEGAL_REQUEST, .asc = 0x24, .ascq = 0x00
197 };
198 
199 /* Illegal request, Invalid field in parameter list */
200 const struct SCSISense sense_code_INVALID_PARAM = {
201     .key = ILLEGAL_REQUEST, .asc = 0x26, .ascq = 0x00
202 };
203 
204 /* Illegal request, Parameter list length error */
205 const struct SCSISense sense_code_INVALID_PARAM_LEN = {
206     .key = ILLEGAL_REQUEST, .asc = 0x1a, .ascq = 0x00
207 };
208 
209 /* Illegal request, LUN not supported */
210 const struct SCSISense sense_code_LUN_NOT_SUPPORTED = {
211     .key = ILLEGAL_REQUEST, .asc = 0x25, .ascq = 0x00
212 };
213 
214 /* Illegal request, Saving parameters not supported */
215 const struct SCSISense sense_code_SAVING_PARAMS_NOT_SUPPORTED = {
216     .key = ILLEGAL_REQUEST, .asc = 0x39, .ascq = 0x00
217 };
218 
219 /* Illegal request, Incompatible medium installed */
220 const struct SCSISense sense_code_INCOMPATIBLE_FORMAT = {
221     .key = ILLEGAL_REQUEST, .asc = 0x30, .ascq = 0x00
222 };
223 
224 /* Illegal request, medium removal prevented */
225 const struct SCSISense sense_code_ILLEGAL_REQ_REMOVAL_PREVENTED = {
226     .key = ILLEGAL_REQUEST, .asc = 0x53, .ascq = 0x02
227 };
228 
229 /* Illegal request, Invalid Transfer Tag */
230 const struct SCSISense sense_code_INVALID_TAG = {
231     .key = ILLEGAL_REQUEST, .asc = 0x4b, .ascq = 0x01
232 };
233 
234 /* Command aborted, I/O process terminated */
235 const struct SCSISense sense_code_IO_ERROR = {
236     .key = ABORTED_COMMAND, .asc = 0x00, .ascq = 0x06
237 };
238 
239 /* Command aborted, I_T Nexus loss occurred */
240 const struct SCSISense sense_code_I_T_NEXUS_LOSS = {
241     .key = ABORTED_COMMAND, .asc = 0x29, .ascq = 0x07
242 };
243 
244 /* Command aborted, Logical Unit failure */
245 const struct SCSISense sense_code_LUN_FAILURE = {
246     .key = ABORTED_COMMAND, .asc = 0x3e, .ascq = 0x01
247 };
248 
249 /* Command aborted, Overlapped Commands Attempted */
250 const struct SCSISense sense_code_OVERLAPPED_COMMANDS = {
251     .key = ABORTED_COMMAND, .asc = 0x4e, .ascq = 0x00
252 };
253 
254 /* Command aborted, LUN Communication Failure */
255 const struct SCSISense sense_code_LUN_COMM_FAILURE = {
256     .key = ABORTED_COMMAND, .asc = 0x08, .ascq = 0x00
257 };
258 
259 /* Medium Error, Unrecovered read error */
260 const struct SCSISense sense_code_READ_ERROR = {
261     .key = MEDIUM_ERROR, .asc = 0x11, .ascq = 0x00
262 };
263 
264 /* Not ready, Cause not reportable */
265 const struct SCSISense sense_code_NOT_READY = {
266     .key = NOT_READY, .asc = 0x04, .ascq = 0x00
267 };
268 
269 /* Unit attention, Capacity data has changed */
270 const struct SCSISense sense_code_CAPACITY_CHANGED = {
271     .key = UNIT_ATTENTION, .asc = 0x2a, .ascq = 0x09
272 };
273 
274 /* Unit attention, Power on, reset or bus device reset occurred */
275 const struct SCSISense sense_code_RESET = {
276     .key = UNIT_ATTENTION, .asc = 0x29, .ascq = 0x00
277 };
278 
279 /* Unit attention, SCSI bus reset */
280 const struct SCSISense sense_code_SCSI_BUS_RESET = {
281     .key = UNIT_ATTENTION, .asc = 0x29, .ascq = 0x02
282 };
283 
284 /* Unit attention, No medium */
285 const struct SCSISense sense_code_UNIT_ATTENTION_NO_MEDIUM = {
286     .key = UNIT_ATTENTION, .asc = 0x3a, .ascq = 0x00
287 };
288 
289 /* Unit attention, Medium may have changed */
290 const struct SCSISense sense_code_MEDIUM_CHANGED = {
291     .key = UNIT_ATTENTION, .asc = 0x28, .ascq = 0x00
292 };
293 
294 /* Unit attention, Reported LUNs data has changed */
295 const struct SCSISense sense_code_REPORTED_LUNS_CHANGED = {
296     .key = UNIT_ATTENTION, .asc = 0x3f, .ascq = 0x0e
297 };
298 
299 /* Unit attention, Device internal reset */
300 const struct SCSISense sense_code_DEVICE_INTERNAL_RESET = {
301     .key = UNIT_ATTENTION, .asc = 0x29, .ascq = 0x04
302 };
303 
304 /* Data Protection, Write Protected */
305 const struct SCSISense sense_code_WRITE_PROTECTED = {
306     .key = DATA_PROTECT, .asc = 0x27, .ascq = 0x00
307 };
308 
309 /* Data Protection, Space Allocation Failed Write Protect */
310 const struct SCSISense sense_code_SPACE_ALLOC_FAILED = {
311     .key = DATA_PROTECT, .asc = 0x27, .ascq = 0x07
312 };
313 
314 /*
315  * scsi_convert_sense
316  *
317  * Convert between fixed and descriptor sense buffers
318  */
319 int scsi_convert_sense(uint8_t *in_buf, int in_len,
320                        uint8_t *buf, int len, bool fixed)
321 {
322     SCSISense sense;
323     bool fixed_in;
324 
325     if (in_len == 0) {
326         return scsi_build_sense_buf(buf, len, SENSE_CODE(NO_SENSE), fixed);
327     }
328 
329     fixed_in = (in_buf[0] & 2) == 0;
330     if (fixed == fixed_in) {
331         memcpy(buf, in_buf, MIN(len, in_len));
332         return MIN(len, in_len);
333     } else {
334         sense = scsi_parse_sense_buf(in_buf, in_len);
335         return scsi_build_sense_buf(buf, len, sense, fixed);
336     }
337 }
338 
339 int scsi_sense_to_errno(int key, int asc, int ascq)
340 {
341     switch (key) {
342     case NO_SENSE:
343     case RECOVERED_ERROR:
344     case UNIT_ATTENTION:
345         /* These sense keys are not errors */
346         return 0;
347     case ABORTED_COMMAND: /* COMMAND ABORTED */
348         return ECANCELED;
349     case NOT_READY:
350     case ILLEGAL_REQUEST:
351     case DATA_PROTECT:
352         /* Parse ASCQ */
353         break;
354     default:
355         return EIO;
356     }
357     switch ((asc << 8) | ascq) {
358     case 0x1a00: /* PARAMETER LIST LENGTH ERROR */
359     case 0x2000: /* INVALID OPERATION CODE */
360     case 0x2400: /* INVALID FIELD IN CDB */
361     case 0x2600: /* INVALID FIELD IN PARAMETER LIST */
362         return EINVAL;
363     case 0x2100: /* LBA OUT OF RANGE */
364     case 0x2707: /* SPACE ALLOC FAILED */
365         return ENOSPC;
366     case 0x2500: /* LOGICAL UNIT NOT SUPPORTED */
367         return ENOTSUP;
368     case 0x3a00: /* MEDIUM NOT PRESENT */
369     case 0x3a01: /* MEDIUM NOT PRESENT TRAY CLOSED */
370     case 0x3a02: /* MEDIUM NOT PRESENT TRAY OPEN */
371         return ENOMEDIUM;
372     case 0x2700: /* WRITE PROTECTED */
373         return EACCES;
374     case 0x0401: /* NOT READY, IN PROGRESS OF BECOMING READY */
375         return EAGAIN;
376     case 0x0402: /* NOT READY, INITIALIZING COMMAND REQUIRED */
377         return ENOTCONN;
378     default:
379         return EIO;
380     }
381 }
382 
383 int scsi_sense_buf_to_errno(const uint8_t *in_buf, size_t in_len)
384 {
385     SCSISense sense;
386     if (in_len < 1) {
387         return EIO;
388     }
389 
390     sense = scsi_parse_sense_buf(in_buf, in_len);
391     return scsi_sense_to_errno(sense.key, sense.asc, sense.ascq);
392 }
393 
394 const char *scsi_command_name(uint8_t cmd)
395 {
396     static const char *names[] = {
397         [ TEST_UNIT_READY          ] = "TEST_UNIT_READY",
398         [ REWIND                   ] = "REWIND",
399         [ REQUEST_SENSE            ] = "REQUEST_SENSE",
400         [ FORMAT_UNIT              ] = "FORMAT_UNIT",
401         [ READ_BLOCK_LIMITS        ] = "READ_BLOCK_LIMITS",
402         [ REASSIGN_BLOCKS          ] = "REASSIGN_BLOCKS/INITIALIZE ELEMENT STATUS",
403         /* LOAD_UNLOAD and INITIALIZE_ELEMENT_STATUS use the same operation code */
404         [ READ_6                   ] = "READ_6",
405         [ WRITE_6                  ] = "WRITE_6",
406         [ SET_CAPACITY             ] = "SET_CAPACITY",
407         [ READ_REVERSE             ] = "READ_REVERSE",
408         [ WRITE_FILEMARKS          ] = "WRITE_FILEMARKS",
409         [ SPACE                    ] = "SPACE",
410         [ INQUIRY                  ] = "INQUIRY",
411         [ RECOVER_BUFFERED_DATA    ] = "RECOVER_BUFFERED_DATA",
412         [ MAINTENANCE_IN           ] = "MAINTENANCE_IN",
413         [ MAINTENANCE_OUT          ] = "MAINTENANCE_OUT",
414         [ MODE_SELECT              ] = "MODE_SELECT",
415         [ RESERVE                  ] = "RESERVE",
416         [ RELEASE                  ] = "RELEASE",
417         [ COPY                     ] = "COPY",
418         [ ERASE                    ] = "ERASE",
419         [ MODE_SENSE               ] = "MODE_SENSE",
420         [ START_STOP               ] = "START_STOP/LOAD_UNLOAD",
421         /* LOAD_UNLOAD and START_STOP use the same operation code */
422         [ RECEIVE_DIAGNOSTIC       ] = "RECEIVE_DIAGNOSTIC",
423         [ SEND_DIAGNOSTIC          ] = "SEND_DIAGNOSTIC",
424         [ ALLOW_MEDIUM_REMOVAL     ] = "ALLOW_MEDIUM_REMOVAL",
425         [ READ_CAPACITY_10         ] = "READ_CAPACITY_10",
426         [ READ_10                  ] = "READ_10",
427         [ WRITE_10                 ] = "WRITE_10",
428         [ SEEK_10                  ] = "SEEK_10/POSITION_TO_ELEMENT",
429         /* SEEK_10 and POSITION_TO_ELEMENT use the same operation code */
430         [ WRITE_VERIFY_10          ] = "WRITE_VERIFY_10",
431         [ VERIFY_10                ] = "VERIFY_10",
432         [ SEARCH_HIGH              ] = "SEARCH_HIGH",
433         [ SEARCH_EQUAL             ] = "SEARCH_EQUAL",
434         [ SEARCH_LOW               ] = "SEARCH_LOW",
435         [ SET_LIMITS               ] = "SET_LIMITS",
436         [ PRE_FETCH                ] = "PRE_FETCH/READ_POSITION",
437         /* READ_POSITION and PRE_FETCH use the same operation code */
438         [ SYNCHRONIZE_CACHE        ] = "SYNCHRONIZE_CACHE",
439         [ LOCK_UNLOCK_CACHE        ] = "LOCK_UNLOCK_CACHE",
440         [ READ_DEFECT_DATA         ] = "READ_DEFECT_DATA/INITIALIZE_ELEMENT_STATUS_WITH_RANGE",
441         /* READ_DEFECT_DATA and INITIALIZE_ELEMENT_STATUS_WITH_RANGE use the same operation code */
442         [ MEDIUM_SCAN              ] = "MEDIUM_SCAN",
443         [ COMPARE                  ] = "COMPARE",
444         [ COPY_VERIFY              ] = "COPY_VERIFY",
445         [ WRITE_BUFFER             ] = "WRITE_BUFFER",
446         [ READ_BUFFER              ] = "READ_BUFFER",
447         [ UPDATE_BLOCK             ] = "UPDATE_BLOCK",
448         [ READ_LONG_10             ] = "READ_LONG_10",
449         [ WRITE_LONG_10            ] = "WRITE_LONG_10",
450         [ CHANGE_DEFINITION        ] = "CHANGE_DEFINITION",
451         [ WRITE_SAME_10            ] = "WRITE_SAME_10",
452         [ UNMAP                    ] = "UNMAP",
453         [ READ_TOC                 ] = "READ_TOC",
454         [ REPORT_DENSITY_SUPPORT   ] = "REPORT_DENSITY_SUPPORT",
455         [ SANITIZE                 ] = "SANITIZE",
456         [ GET_CONFIGURATION        ] = "GET_CONFIGURATION",
457         [ LOG_SELECT               ] = "LOG_SELECT",
458         [ LOG_SENSE                ] = "LOG_SENSE",
459         [ MODE_SELECT_10           ] = "MODE_SELECT_10",
460         [ RESERVE_10               ] = "RESERVE_10",
461         [ RELEASE_10               ] = "RELEASE_10",
462         [ MODE_SENSE_10            ] = "MODE_SENSE_10",
463         [ PERSISTENT_RESERVE_IN    ] = "PERSISTENT_RESERVE_IN",
464         [ PERSISTENT_RESERVE_OUT   ] = "PERSISTENT_RESERVE_OUT",
465         [ WRITE_FILEMARKS_16       ] = "WRITE_FILEMARKS_16",
466         [ EXTENDED_COPY            ] = "EXTENDED_COPY",
467         [ ATA_PASSTHROUGH_16       ] = "ATA_PASSTHROUGH_16",
468         [ ACCESS_CONTROL_IN        ] = "ACCESS_CONTROL_IN",
469         [ ACCESS_CONTROL_OUT       ] = "ACCESS_CONTROL_OUT",
470         [ READ_16                  ] = "READ_16",
471         [ COMPARE_AND_WRITE        ] = "COMPARE_AND_WRITE",
472         [ WRITE_16                 ] = "WRITE_16",
473         [ WRITE_VERIFY_16          ] = "WRITE_VERIFY_16",
474         [ VERIFY_16                ] = "VERIFY_16",
475         [ PRE_FETCH_16             ] = "PRE_FETCH_16",
476         [ SYNCHRONIZE_CACHE_16     ] = "SPACE_16/SYNCHRONIZE_CACHE_16",
477         /* SPACE_16 and SYNCHRONIZE_CACHE_16 use the same operation code */
478         [ LOCATE_16                ] = "LOCATE_16",
479         [ WRITE_SAME_16            ] = "ERASE_16/WRITE_SAME_16",
480         /* ERASE_16 and WRITE_SAME_16 use the same operation code */
481         [ SERVICE_ACTION_IN_16     ] = "SERVICE_ACTION_IN_16",
482         [ WRITE_LONG_16            ] = "WRITE_LONG_16",
483         [ REPORT_LUNS              ] = "REPORT_LUNS",
484         [ ATA_PASSTHROUGH_12       ] = "BLANK/ATA_PASSTHROUGH_12",
485         [ MOVE_MEDIUM              ] = "MOVE_MEDIUM",
486         [ EXCHANGE_MEDIUM          ] = "EXCHANGE MEDIUM",
487         [ READ_12                  ] = "READ_12",
488         [ WRITE_12                 ] = "WRITE_12",
489         [ ERASE_12                 ] = "ERASE_12/GET_PERFORMANCE",
490         /* ERASE_12 and GET_PERFORMANCE use the same operation code */
491         [ SERVICE_ACTION_IN_12     ] = "SERVICE_ACTION_IN_12",
492         [ WRITE_VERIFY_12          ] = "WRITE_VERIFY_12",
493         [ VERIFY_12                ] = "VERIFY_12",
494         [ SEARCH_HIGH_12           ] = "SEARCH_HIGH_12",
495         [ SEARCH_EQUAL_12          ] = "SEARCH_EQUAL_12",
496         [ SEARCH_LOW_12            ] = "SEARCH_LOW_12",
497         [ READ_ELEMENT_STATUS      ] = "READ_ELEMENT_STATUS",
498         [ SEND_VOLUME_TAG          ] = "SEND_VOLUME_TAG/SET_STREAMING",
499         /* SEND_VOLUME_TAG and SET_STREAMING use the same operation code */
500         [ READ_CD                  ] = "READ_CD",
501         [ READ_DEFECT_DATA_12      ] = "READ_DEFECT_DATA_12",
502         [ READ_DVD_STRUCTURE       ] = "READ_DVD_STRUCTURE",
503         [ RESERVE_TRACK            ] = "RESERVE_TRACK",
504         [ SEND_CUE_SHEET           ] = "SEND_CUE_SHEET",
505         [ SEND_DVD_STRUCTURE       ] = "SEND_DVD_STRUCTURE",
506         [ SET_CD_SPEED             ] = "SET_CD_SPEED",
507         [ SET_READ_AHEAD           ] = "SET_READ_AHEAD",
508         [ ALLOW_OVERWRITE          ] = "ALLOW_OVERWRITE",
509         [ MECHANISM_STATUS         ] = "MECHANISM_STATUS",
510         [ GET_EVENT_STATUS_NOTIFICATION ] = "GET_EVENT_STATUS_NOTIFICATION",
511         [ READ_DISC_INFORMATION    ] = "READ_DISC_INFORMATION",
512     };
513 
514     if (cmd >= ARRAY_SIZE(names) || names[cmd] == NULL) {
515         return "*UNKNOWN*";
516     }
517     return names[cmd];
518 }
519 
520 #ifdef CONFIG_LINUX
521 int sg_io_sense_from_errno(int errno_value, struct sg_io_hdr *io_hdr,
522                            SCSISense *sense)
523 {
524     if (errno_value != 0) {
525         switch (errno_value) {
526         case EDOM:
527             return TASK_SET_FULL;
528         case ENOMEM:
529             *sense = SENSE_CODE(TARGET_FAILURE);
530             return CHECK_CONDITION;
531         default:
532             *sense = SENSE_CODE(IO_ERROR);
533             return CHECK_CONDITION;
534         }
535     } else {
536         if (io_hdr->host_status == SG_ERR_DID_NO_CONNECT ||
537             io_hdr->host_status == SG_ERR_DID_BUS_BUSY ||
538             io_hdr->host_status == SG_ERR_DID_TIME_OUT ||
539             (io_hdr->driver_status & SG_ERR_DRIVER_TIMEOUT)) {
540             return BUSY;
541         } else if (io_hdr->host_status) {
542             *sense = SENSE_CODE(I_T_NEXUS_LOSS);
543             return CHECK_CONDITION;
544         } else if (io_hdr->status) {
545             return io_hdr->status;
546         } else if (io_hdr->driver_status & SG_ERR_DRIVER_SENSE) {
547             return CHECK_CONDITION;
548         } else {
549             return GOOD;
550         }
551     }
552 }
553 #endif
554