xref: /openbmc/qemu/hw/ide/atapi.c (revision c51a3f5d)
1 /*
2  * QEMU ATAPI Emulation
3  *
4  * Copyright (c) 2003 Fabrice Bellard
5  * Copyright (c) 2006 Openedhand Ltd.
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "hw/ide/internal.h"
28 #include "hw/scsi/scsi.h"
29 #include "sysemu/block-backend.h"
30 #include "trace.h"
31 
32 #define ATAPI_SECTOR_BITS (2 + BDRV_SECTOR_BITS)
33 #define ATAPI_SECTOR_SIZE (1 << ATAPI_SECTOR_BITS)
34 
35 static void ide_atapi_cmd_read_dma_cb(void *opaque, int ret);
36 
37 static void padstr8(uint8_t *buf, int buf_size, const char *src)
38 {
39     int i;
40     for(i = 0; i < buf_size; i++) {
41         if (*src)
42             buf[i] = *src++;
43         else
44             buf[i] = ' ';
45     }
46 }
47 
48 static void lba_to_msf(uint8_t *buf, int lba)
49 {
50     lba += 150;
51     buf[0] = (lba / 75) / 60;
52     buf[1] = (lba / 75) % 60;
53     buf[2] = lba % 75;
54 }
55 
56 static inline int media_present(IDEState *s)
57 {
58     return !s->tray_open && s->nb_sectors > 0;
59 }
60 
61 /* XXX: DVDs that could fit on a CD will be reported as a CD */
62 static inline int media_is_dvd(IDEState *s)
63 {
64     return (media_present(s) && s->nb_sectors > CD_MAX_SECTORS);
65 }
66 
67 static inline int media_is_cd(IDEState *s)
68 {
69     return (media_present(s) && s->nb_sectors <= CD_MAX_SECTORS);
70 }
71 
72 static void cd_data_to_raw(uint8_t *buf, int lba)
73 {
74     /* sync bytes */
75     buf[0] = 0x00;
76     memset(buf + 1, 0xff, 10);
77     buf[11] = 0x00;
78     buf += 12;
79     /* MSF */
80     lba_to_msf(buf, lba);
81     buf[3] = 0x01; /* mode 1 data */
82     buf += 4;
83     /* data */
84     buf += 2048;
85     /* XXX: ECC not computed */
86     memset(buf, 0, 288);
87 }
88 
89 static int
90 cd_read_sector_sync(IDEState *s)
91 {
92     int ret;
93     block_acct_start(blk_get_stats(s->blk), &s->acct,
94                      ATAPI_SECTOR_SIZE, BLOCK_ACCT_READ);
95 
96     trace_cd_read_sector_sync(s->lba);
97 
98     switch (s->cd_sector_size) {
99     case 2048:
100         ret = blk_pread(s->blk, (int64_t)s->lba << ATAPI_SECTOR_BITS,
101                         s->io_buffer, ATAPI_SECTOR_SIZE);
102         break;
103     case 2352:
104         ret = blk_pread(s->blk, (int64_t)s->lba << ATAPI_SECTOR_BITS,
105                         s->io_buffer + 16, ATAPI_SECTOR_SIZE);
106         if (ret >= 0) {
107             cd_data_to_raw(s->io_buffer, s->lba);
108         }
109         break;
110     default:
111         block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_READ);
112         return -EIO;
113     }
114 
115     if (ret < 0) {
116         block_acct_failed(blk_get_stats(s->blk), &s->acct);
117     } else {
118         block_acct_done(blk_get_stats(s->blk), &s->acct);
119         s->lba++;
120         s->io_buffer_index = 0;
121     }
122 
123     return ret;
124 }
125 
126 static void cd_read_sector_cb(void *opaque, int ret)
127 {
128     IDEState *s = opaque;
129 
130     trace_cd_read_sector_cb(s->lba, ret);
131 
132     if (ret < 0) {
133         block_acct_failed(blk_get_stats(s->blk), &s->acct);
134         ide_atapi_io_error(s, ret);
135         return;
136     }
137 
138     block_acct_done(blk_get_stats(s->blk), &s->acct);
139 
140     if (s->cd_sector_size == 2352) {
141         cd_data_to_raw(s->io_buffer, s->lba);
142     }
143 
144     s->lba++;
145     s->io_buffer_index = 0;
146     s->status &= ~BUSY_STAT;
147 
148     ide_atapi_cmd_reply_end(s);
149 }
150 
151 static int cd_read_sector(IDEState *s)
152 {
153     void *buf;
154 
155     if (s->cd_sector_size != 2048 && s->cd_sector_size != 2352) {
156         block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_READ);
157         return -EINVAL;
158     }
159 
160     buf = (s->cd_sector_size == 2352) ? s->io_buffer + 16 : s->io_buffer;
161     qemu_iovec_init_buf(&s->qiov, buf, ATAPI_SECTOR_SIZE);
162 
163     trace_cd_read_sector(s->lba);
164 
165     block_acct_start(blk_get_stats(s->blk), &s->acct,
166                      ATAPI_SECTOR_SIZE, BLOCK_ACCT_READ);
167 
168     ide_buffered_readv(s, (int64_t)s->lba << 2, &s->qiov, 4,
169                        cd_read_sector_cb, s);
170 
171     s->status |= BUSY_STAT;
172     return 0;
173 }
174 
175 void ide_atapi_cmd_ok(IDEState *s)
176 {
177     s->error = 0;
178     s->status = READY_STAT | SEEK_STAT;
179     s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;
180     ide_transfer_stop(s);
181     ide_set_irq(s->bus);
182 }
183 
184 void ide_atapi_cmd_error(IDEState *s, int sense_key, int asc)
185 {
186     trace_ide_atapi_cmd_error(s, sense_key, asc);
187     s->error = sense_key << 4;
188     s->status = READY_STAT | ERR_STAT;
189     s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;
190     s->sense_key = sense_key;
191     s->asc = asc;
192     ide_transfer_stop(s);
193     ide_set_irq(s->bus);
194 }
195 
196 void ide_atapi_io_error(IDEState *s, int ret)
197 {
198     /* XXX: handle more errors */
199     if (ret == -ENOMEDIUM) {
200         ide_atapi_cmd_error(s, NOT_READY,
201                             ASC_MEDIUM_NOT_PRESENT);
202     } else {
203         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
204                             ASC_LOGICAL_BLOCK_OOR);
205     }
206 }
207 
208 static uint16_t atapi_byte_count_limit(IDEState *s)
209 {
210     uint16_t bcl;
211 
212     bcl = s->lcyl | (s->hcyl << 8);
213     if (bcl == 0xffff) {
214         return 0xfffe;
215     }
216     return bcl;
217 }
218 
219 /* The whole ATAPI transfer logic is handled in this function */
220 void ide_atapi_cmd_reply_end(IDEState *s)
221 {
222     int byte_count_limit, size, ret;
223     while (s->packet_transfer_size > 0) {
224         trace_ide_atapi_cmd_reply_end(s, s->packet_transfer_size,
225                                       s->elementary_transfer_size,
226                                       s->io_buffer_index);
227 
228         /* see if a new sector must be read */
229         if (s->lba != -1 && s->io_buffer_index >= s->cd_sector_size) {
230             if (!s->elementary_transfer_size) {
231                 ret = cd_read_sector(s);
232                 if (ret < 0) {
233                     ide_atapi_io_error(s, ret);
234                 }
235                 return;
236             } else {
237                 /* rebuffering within an elementary transfer is
238                  * only possible with a sync request because we
239                  * end up with a race condition otherwise */
240                 ret = cd_read_sector_sync(s);
241                 if (ret < 0) {
242                     ide_atapi_io_error(s, ret);
243                     return;
244                 }
245             }
246         }
247         if (s->elementary_transfer_size > 0) {
248             /* there are some data left to transmit in this elementary
249                transfer */
250             size = s->cd_sector_size - s->io_buffer_index;
251             if (size > s->elementary_transfer_size)
252                 size = s->elementary_transfer_size;
253         } else {
254             /* a new transfer is needed */
255             s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO;
256             ide_set_irq(s->bus);
257             byte_count_limit = atapi_byte_count_limit(s);
258             trace_ide_atapi_cmd_reply_end_bcl(s, byte_count_limit);
259             size = s->packet_transfer_size;
260             if (size > byte_count_limit) {
261                 /* byte count limit must be even if this case */
262                 if (byte_count_limit & 1)
263                     byte_count_limit--;
264                 size = byte_count_limit;
265             }
266             s->lcyl = size;
267             s->hcyl = size >> 8;
268             s->elementary_transfer_size = size;
269             /* we cannot transmit more than one sector at a time */
270             if (s->lba != -1) {
271                 if (size > (s->cd_sector_size - s->io_buffer_index))
272                     size = (s->cd_sector_size - s->io_buffer_index);
273             }
274             trace_ide_atapi_cmd_reply_end_new(s, s->status);
275         }
276         s->packet_transfer_size -= size;
277         s->elementary_transfer_size -= size;
278         s->io_buffer_index += size;
279 
280         /* Some adapters process PIO data right away.  In that case, we need
281          * to avoid mutual recursion between ide_transfer_start
282          * and ide_atapi_cmd_reply_end.
283          */
284         if (!ide_transfer_start_norecurse(s,
285                                           s->io_buffer + s->io_buffer_index - size,
286                                           size, ide_atapi_cmd_reply_end)) {
287             return;
288         }
289     }
290 
291     /* end of transfer */
292     trace_ide_atapi_cmd_reply_end_eot(s, s->status);
293     ide_atapi_cmd_ok(s);
294     ide_set_irq(s->bus);
295 }
296 
297 /* send a reply of 'size' bytes in s->io_buffer to an ATAPI command */
298 static void ide_atapi_cmd_reply(IDEState *s, int size, int max_size)
299 {
300     if (size > max_size)
301         size = max_size;
302     s->lba = -1; /* no sector read */
303     s->packet_transfer_size = size;
304     s->io_buffer_size = size;    /* dma: send the reply data as one chunk */
305     s->elementary_transfer_size = 0;
306 
307     if (s->atapi_dma) {
308         block_acct_start(blk_get_stats(s->blk), &s->acct, size,
309                          BLOCK_ACCT_READ);
310         s->status = READY_STAT | SEEK_STAT | DRQ_STAT;
311         ide_start_dma(s, ide_atapi_cmd_read_dma_cb);
312     } else {
313         s->status = READY_STAT | SEEK_STAT;
314         s->io_buffer_index = 0;
315         ide_atapi_cmd_reply_end(s);
316     }
317 }
318 
319 /* start a CD-CDROM read command */
320 static void ide_atapi_cmd_read_pio(IDEState *s, int lba, int nb_sectors,
321                                    int sector_size)
322 {
323     s->lba = lba;
324     s->packet_transfer_size = nb_sectors * sector_size;
325     s->elementary_transfer_size = 0;
326     s->io_buffer_index = sector_size;
327     s->cd_sector_size = sector_size;
328 
329     ide_atapi_cmd_reply_end(s);
330 }
331 
332 static void ide_atapi_cmd_check_status(IDEState *s)
333 {
334     trace_ide_atapi_cmd_check_status(s);
335     s->error = MC_ERR | (UNIT_ATTENTION << 4);
336     s->status = ERR_STAT;
337     s->nsector = 0;
338     ide_set_irq(s->bus);
339 }
340 /* ATAPI DMA support */
341 
342 static void ide_atapi_cmd_read_dma_cb(void *opaque, int ret)
343 {
344     IDEState *s = opaque;
345     int data_offset, n;
346 
347     if (ret < 0) {
348         if (ide_handle_rw_error(s, -ret, ide_dma_cmd_to_retry(s->dma_cmd))) {
349             if (s->bus->error_status) {
350                 s->bus->dma->aiocb = NULL;
351                 return;
352             }
353             goto eot;
354         }
355     }
356 
357     if (s->io_buffer_size > 0) {
358         /*
359          * For a cdrom read sector command (s->lba != -1),
360          * adjust the lba for the next s->io_buffer_size chunk
361          * and dma the current chunk.
362          * For a command != read (s->lba == -1), just transfer
363          * the reply data.
364          */
365         if (s->lba != -1) {
366             if (s->cd_sector_size == 2352) {
367                 n = 1;
368                 cd_data_to_raw(s->io_buffer, s->lba);
369             } else {
370                 n = s->io_buffer_size >> 11;
371             }
372             s->lba += n;
373         }
374         s->packet_transfer_size -= s->io_buffer_size;
375         if (s->bus->dma->ops->rw_buf(s->bus->dma, 1) == 0)
376             goto eot;
377     }
378 
379     if (s->packet_transfer_size <= 0) {
380         s->status = READY_STAT | SEEK_STAT;
381         s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;
382         ide_set_irq(s->bus);
383         goto eot;
384     }
385 
386     s->io_buffer_index = 0;
387     if (s->cd_sector_size == 2352) {
388         n = 1;
389         s->io_buffer_size = s->cd_sector_size;
390         data_offset = 16;
391     } else {
392         n = s->packet_transfer_size >> 11;
393         if (n > (IDE_DMA_BUF_SECTORS / 4))
394             n = (IDE_DMA_BUF_SECTORS / 4);
395         s->io_buffer_size = n * 2048;
396         data_offset = 0;
397     }
398     trace_ide_atapi_cmd_read_dma_cb_aio(s, s->lba, n);
399     qemu_iovec_init_buf(&s->bus->dma->qiov, s->io_buffer + data_offset,
400                         n * ATAPI_SECTOR_SIZE);
401 
402     s->bus->dma->aiocb = ide_buffered_readv(s, (int64_t)s->lba << 2,
403                                             &s->bus->dma->qiov, n * 4,
404                                             ide_atapi_cmd_read_dma_cb, s);
405     return;
406 
407 eot:
408     if (ret < 0) {
409         block_acct_failed(blk_get_stats(s->blk), &s->acct);
410     } else {
411         block_acct_done(blk_get_stats(s->blk), &s->acct);
412     }
413     ide_set_inactive(s, false);
414 }
415 
416 /* start a CD-CDROM read command with DMA */
417 /* XXX: test if DMA is available */
418 static void ide_atapi_cmd_read_dma(IDEState *s, int lba, int nb_sectors,
419                                    int sector_size)
420 {
421     s->lba = lba;
422     s->packet_transfer_size = nb_sectors * sector_size;
423     s->io_buffer_size = 0;
424     s->cd_sector_size = sector_size;
425 
426     block_acct_start(blk_get_stats(s->blk), &s->acct, s->packet_transfer_size,
427                      BLOCK_ACCT_READ);
428 
429     /* XXX: check if BUSY_STAT should be set */
430     s->status = READY_STAT | SEEK_STAT | DRQ_STAT | BUSY_STAT;
431     ide_start_dma(s, ide_atapi_cmd_read_dma_cb);
432 }
433 
434 static void ide_atapi_cmd_read(IDEState *s, int lba, int nb_sectors,
435                                int sector_size)
436 {
437     trace_ide_atapi_cmd_read(s, s->atapi_dma ? "dma" : "pio",
438                              lba, nb_sectors);
439     if (s->atapi_dma) {
440         ide_atapi_cmd_read_dma(s, lba, nb_sectors, sector_size);
441     } else {
442         ide_atapi_cmd_read_pio(s, lba, nb_sectors, sector_size);
443     }
444 }
445 
446 void ide_atapi_dma_restart(IDEState *s)
447 {
448     /*
449      * At this point we can just re-evaluate the packet command and start over.
450      * The presence of ->dma_cb callback in the pre_save ensures that the packet
451      * command has been completely sent and we can safely restart command.
452      */
453     s->unit = s->bus->retry_unit;
454     s->bus->dma->ops->restart_dma(s->bus->dma);
455     ide_atapi_cmd(s);
456 }
457 
458 static inline uint8_t ide_atapi_set_profile(uint8_t *buf, uint8_t *index,
459                                             uint16_t profile)
460 {
461     uint8_t *buf_profile = buf + 12; /* start of profiles */
462 
463     buf_profile += ((*index) * 4); /* start of indexed profile */
464     stw_be_p(buf_profile, profile);
465     buf_profile[2] = ((buf_profile[0] == buf[6]) && (buf_profile[1] == buf[7]));
466 
467     /* each profile adds 4 bytes to the response */
468     (*index)++;
469     buf[11] += 4; /* Additional Length */
470 
471     return 4;
472 }
473 
474 static int ide_dvd_read_structure(IDEState *s, int format,
475                                   const uint8_t *packet, uint8_t *buf)
476 {
477     switch (format) {
478         case 0x0: /* Physical format information */
479             {
480                 int layer = packet[6];
481                 uint64_t total_sectors;
482 
483                 if (layer != 0)
484                     return -ASC_INV_FIELD_IN_CMD_PACKET;
485 
486                 total_sectors = s->nb_sectors >> 2;
487                 if (total_sectors == 0) {
488                     return -ASC_MEDIUM_NOT_PRESENT;
489                 }
490 
491                 buf[4] = 1;   /* DVD-ROM, part version 1 */
492                 buf[5] = 0xf; /* 120mm disc, minimum rate unspecified */
493                 buf[6] = 1;   /* one layer, read-only (per MMC-2 spec) */
494                 buf[7] = 0;   /* default densities */
495 
496                 /* FIXME: 0x30000 per spec? */
497                 stl_be_p(buf + 8, 0); /* start sector */
498                 stl_be_p(buf + 12, total_sectors - 1); /* end sector */
499                 stl_be_p(buf + 16, total_sectors - 1); /* l0 end sector */
500 
501                 /* Size of buffer, not including 2 byte size field */
502                 stw_be_p(buf, 2048 + 2);
503 
504                 /* 2k data + 4 byte header */
505                 return (2048 + 4);
506             }
507 
508         case 0x01: /* DVD copyright information */
509             buf[4] = 0; /* no copyright data */
510             buf[5] = 0; /* no region restrictions */
511 
512             /* Size of buffer, not including 2 byte size field */
513             stw_be_p(buf, 4 + 2);
514 
515             /* 4 byte header + 4 byte data */
516             return (4 + 4);
517 
518         case 0x03: /* BCA information - invalid field for no BCA info */
519             return -ASC_INV_FIELD_IN_CMD_PACKET;
520 
521         case 0x04: /* DVD disc manufacturing information */
522             /* Size of buffer, not including 2 byte size field */
523             stw_be_p(buf, 2048 + 2);
524 
525             /* 2k data + 4 byte header */
526             return (2048 + 4);
527 
528         case 0xff:
529             /*
530              * This lists all the command capabilities above.  Add new ones
531              * in order and update the length and buffer return values.
532              */
533 
534             buf[4] = 0x00; /* Physical format */
535             buf[5] = 0x40; /* Not writable, is readable */
536             stw_be_p(buf + 6, 2048 + 4);
537 
538             buf[8] = 0x01; /* Copyright info */
539             buf[9] = 0x40; /* Not writable, is readable */
540             stw_be_p(buf + 10, 4 + 4);
541 
542             buf[12] = 0x03; /* BCA info */
543             buf[13] = 0x40; /* Not writable, is readable */
544             stw_be_p(buf + 14, 188 + 4);
545 
546             buf[16] = 0x04; /* Manufacturing info */
547             buf[17] = 0x40; /* Not writable, is readable */
548             stw_be_p(buf + 18, 2048 + 4);
549 
550             /* Size of buffer, not including 2 byte size field */
551             stw_be_p(buf, 16 + 2);
552 
553             /* data written + 4 byte header */
554             return (16 + 4);
555 
556         default: /* TODO: formats beyond DVD-ROM requires */
557             return -ASC_INV_FIELD_IN_CMD_PACKET;
558     }
559 }
560 
561 static unsigned int event_status_media(IDEState *s,
562                                        uint8_t *buf)
563 {
564     uint8_t event_code, media_status;
565 
566     media_status = 0;
567     if (s->tray_open) {
568         media_status = MS_TRAY_OPEN;
569     } else if (blk_is_inserted(s->blk)) {
570         media_status = MS_MEDIA_PRESENT;
571     }
572 
573     /* Event notification descriptor */
574     event_code = MEC_NO_CHANGE;
575     if (media_status != MS_TRAY_OPEN) {
576         if (s->events.new_media) {
577             event_code = MEC_NEW_MEDIA;
578             s->events.new_media = false;
579         } else if (s->events.eject_request) {
580             event_code = MEC_EJECT_REQUESTED;
581             s->events.eject_request = false;
582         }
583     }
584 
585     buf[4] = event_code;
586     buf[5] = media_status;
587 
588     /* These fields are reserved, just clear them. */
589     buf[6] = 0;
590     buf[7] = 0;
591 
592     return 8; /* We wrote to 4 extra bytes from the header */
593 }
594 
595 /*
596  * Before transferring data or otherwise signalling acceptance of a command
597  * marked CONDDATA, we must check the validity of the byte_count_limit.
598  */
599 static bool validate_bcl(IDEState *s)
600 {
601     /* TODO: Check IDENTIFY data word 125 for defacult BCL (currently 0) */
602     if (s->atapi_dma || atapi_byte_count_limit(s)) {
603         return true;
604     }
605 
606     /* TODO: Move abort back into core.c and introduce proper error flow between
607      *       ATAPI layer and IDE core layer */
608     ide_abort_command(s);
609     return false;
610 }
611 
612 static void cmd_get_event_status_notification(IDEState *s,
613                                               uint8_t *buf)
614 {
615     const uint8_t *packet = buf;
616 
617     struct {
618         uint8_t opcode;
619         uint8_t polled;        /* lsb bit is polled; others are reserved */
620         uint8_t reserved2[2];
621         uint8_t class;
622         uint8_t reserved3[2];
623         uint16_t len;
624         uint8_t control;
625     } QEMU_PACKED *gesn_cdb;
626 
627     struct {
628         uint16_t len;
629         uint8_t notification_class;
630         uint8_t supported_events;
631     } QEMU_PACKED *gesn_event_header;
632     unsigned int max_len, used_len;
633 
634     gesn_cdb = (void *)packet;
635     gesn_event_header = (void *)buf;
636 
637     max_len = be16_to_cpu(gesn_cdb->len);
638 
639     /* It is fine by the MMC spec to not support async mode operations */
640     if (!(gesn_cdb->polled & 0x01)) { /* asynchronous mode */
641         /* Only polling is supported, asynchronous mode is not. */
642         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
643                             ASC_INV_FIELD_IN_CMD_PACKET);
644         return;
645     }
646 
647     /* polling mode operation */
648 
649     /*
650      * These are the supported events.
651      *
652      * We currently only support requests of the 'media' type.
653      * Notification class requests and supported event classes are bitmasks,
654      * but they are build from the same values as the "notification class"
655      * field.
656      */
657     gesn_event_header->supported_events = 1 << GESN_MEDIA;
658 
659     /*
660      * We use |= below to set the class field; other bits in this byte
661      * are reserved now but this is useful to do if we have to use the
662      * reserved fields later.
663      */
664     gesn_event_header->notification_class = 0;
665 
666     /*
667      * Responses to requests are to be based on request priority.  The
668      * notification_class_request_type enum above specifies the
669      * priority: upper elements are higher prio than lower ones.
670      */
671     if (gesn_cdb->class & (1 << GESN_MEDIA)) {
672         gesn_event_header->notification_class |= GESN_MEDIA;
673         used_len = event_status_media(s, buf);
674     } else {
675         gesn_event_header->notification_class = 0x80; /* No event available */
676         used_len = sizeof(*gesn_event_header);
677     }
678     gesn_event_header->len = cpu_to_be16(used_len
679                                          - sizeof(*gesn_event_header));
680     ide_atapi_cmd_reply(s, used_len, max_len);
681 }
682 
683 static void cmd_request_sense(IDEState *s, uint8_t *buf)
684 {
685     int max_len = buf[4];
686 
687     memset(buf, 0, 18);
688     buf[0] = 0x70 | (1 << 7);
689     buf[2] = s->sense_key;
690     buf[7] = 10;
691     buf[12] = s->asc;
692 
693     if (s->sense_key == UNIT_ATTENTION) {
694         s->sense_key = NO_SENSE;
695     }
696 
697     ide_atapi_cmd_reply(s, 18, max_len);
698 }
699 
700 static void cmd_inquiry(IDEState *s, uint8_t *buf)
701 {
702     uint8_t page_code = buf[2];
703     int max_len = buf[4];
704 
705     unsigned idx = 0;
706     unsigned size_idx;
707     unsigned preamble_len;
708 
709     /* If the EVPD (Enable Vital Product Data) bit is set in byte 1,
710      * we are being asked for a specific page of info indicated by byte 2. */
711     if (buf[1] & 0x01) {
712         preamble_len = 4;
713         size_idx = 3;
714 
715         buf[idx++] = 0x05;      /* CD-ROM */
716         buf[idx++] = page_code; /* Page Code */
717         buf[idx++] = 0x00;      /* reserved */
718         idx++;                  /* length (set later) */
719 
720         switch (page_code) {
721         case 0x00:
722             /* Supported Pages: List of supported VPD responses. */
723             buf[idx++] = 0x00; /* 0x00: Supported Pages, and: */
724             buf[idx++] = 0x83; /* 0x83: Device Identification. */
725             break;
726 
727         case 0x83:
728             /* Device Identification. Each entry is optional, but the entries
729              * included here are modeled after libata's VPD responses.
730              * If the response is given, at least one entry must be present. */
731 
732             /* Entry 1: Serial */
733             if (idx + 24 > max_len) {
734                 /* Not enough room for even the first entry: */
735                 /* 4 byte header + 20 byte string */
736                 ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
737                                     ASC_DATA_PHASE_ERROR);
738                 return;
739             }
740             buf[idx++] = 0x02; /* Ascii */
741             buf[idx++] = 0x00; /* Vendor Specific */
742             buf[idx++] = 0x00;
743             buf[idx++] = 20;   /* Remaining length */
744             padstr8(buf + idx, 20, s->drive_serial_str);
745             idx += 20;
746 
747             /* Entry 2: Drive Model and Serial */
748             if (idx + 72 > max_len) {
749                 /* 4 (header) + 8 (vendor) + 60 (model & serial) */
750                 goto out;
751             }
752             buf[idx++] = 0x02; /* Ascii */
753             buf[idx++] = 0x01; /* T10 Vendor */
754             buf[idx++] = 0x00;
755             buf[idx++] = 68;
756             padstr8(buf + idx, 8, "ATA"); /* Generic T10 vendor */
757             idx += 8;
758             padstr8(buf + idx, 40, s->drive_model_str);
759             idx += 40;
760             padstr8(buf + idx, 20, s->drive_serial_str);
761             idx += 20;
762 
763             /* Entry 3: WWN */
764             if (s->wwn && (idx + 12 <= max_len)) {
765                 /* 4 byte header + 8 byte wwn */
766                 buf[idx++] = 0x01; /* Binary */
767                 buf[idx++] = 0x03; /* NAA */
768                 buf[idx++] = 0x00;
769                 buf[idx++] = 0x08;
770                 stq_be_p(&buf[idx], s->wwn);
771                 idx += 8;
772             }
773             break;
774 
775         default:
776             /* SPC-3, revision 23 sec. 6.4 */
777             ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
778                                 ASC_INV_FIELD_IN_CMD_PACKET);
779             return;
780         }
781     } else {
782         preamble_len = 5;
783         size_idx = 4;
784 
785         buf[0] = 0x05; /* CD-ROM */
786         buf[1] = 0x80; /* removable */
787         buf[2] = 0x00; /* ISO */
788         buf[3] = 0x21; /* ATAPI-2 (XXX: put ATAPI-4 ?) */
789         /* buf[size_idx] set below. */
790         buf[5] = 0;    /* reserved */
791         buf[6] = 0;    /* reserved */
792         buf[7] = 0;    /* reserved */
793         padstr8(buf + 8, 8, "QEMU");
794         padstr8(buf + 16, 16, "QEMU DVD-ROM");
795         padstr8(buf + 32, 4, s->version);
796         idx = 36;
797     }
798 
799  out:
800     buf[size_idx] = idx - preamble_len;
801     ide_atapi_cmd_reply(s, idx, max_len);
802 }
803 
804 static void cmd_get_configuration(IDEState *s, uint8_t *buf)
805 {
806     uint32_t len;
807     uint8_t index = 0;
808     int max_len;
809 
810     /* only feature 0 is supported */
811     if (buf[2] != 0 || buf[3] != 0) {
812         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
813                             ASC_INV_FIELD_IN_CMD_PACKET);
814         return;
815     }
816 
817     /* XXX: could result in alignment problems in some architectures */
818     max_len = lduw_be_p(buf + 7);
819 
820     /*
821      * XXX: avoid overflow for io_buffer if max_len is bigger than
822      *      the size of that buffer (dimensioned to max number of
823      *      sectors to transfer at once)
824      *
825      *      Only a problem if the feature/profiles grow.
826      */
827     if (max_len > BDRV_SECTOR_SIZE) {
828         /* XXX: assume 1 sector */
829         max_len = BDRV_SECTOR_SIZE;
830     }
831 
832     memset(buf, 0, max_len);
833     /*
834      * the number of sectors from the media tells us which profile
835      * to use as current.  0 means there is no media
836      */
837     if (media_is_dvd(s)) {
838         stw_be_p(buf + 6, MMC_PROFILE_DVD_ROM);
839     } else if (media_is_cd(s)) {
840         stw_be_p(buf + 6, MMC_PROFILE_CD_ROM);
841     }
842 
843     buf[10] = 0x02 | 0x01; /* persistent and current */
844     len = 12; /* headers: 8 + 4 */
845     len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_DVD_ROM);
846     len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_CD_ROM);
847     stl_be_p(buf, len - 4); /* data length */
848 
849     ide_atapi_cmd_reply(s, len, max_len);
850 }
851 
852 static void cmd_mode_sense(IDEState *s, uint8_t *buf)
853 {
854     int action, code;
855     int max_len;
856 
857     max_len = lduw_be_p(buf + 7);
858     action = buf[2] >> 6;
859     code = buf[2] & 0x3f;
860 
861     switch(action) {
862     case 0: /* current values */
863         switch(code) {
864         case MODE_PAGE_R_W_ERROR: /* error recovery */
865             stw_be_p(&buf[0], 16 - 2);
866             buf[2] = 0x70;
867             buf[3] = 0;
868             buf[4] = 0;
869             buf[5] = 0;
870             buf[6] = 0;
871             buf[7] = 0;
872 
873             buf[8] = MODE_PAGE_R_W_ERROR;
874             buf[9] = 16 - 10;
875             buf[10] = 0x00;
876             buf[11] = 0x05;
877             buf[12] = 0x00;
878             buf[13] = 0x00;
879             buf[14] = 0x00;
880             buf[15] = 0x00;
881             ide_atapi_cmd_reply(s, 16, max_len);
882             break;
883         case MODE_PAGE_AUDIO_CTL:
884             stw_be_p(&buf[0], 24 - 2);
885             buf[2] = 0x70;
886             buf[3] = 0;
887             buf[4] = 0;
888             buf[5] = 0;
889             buf[6] = 0;
890             buf[7] = 0;
891 
892             buf[8] = MODE_PAGE_AUDIO_CTL;
893             buf[9] = 24 - 10;
894             /* Fill with CDROM audio volume */
895             buf[17] = 0;
896             buf[19] = 0;
897             buf[21] = 0;
898             buf[23] = 0;
899 
900             ide_atapi_cmd_reply(s, 24, max_len);
901             break;
902         case MODE_PAGE_CAPABILITIES:
903             stw_be_p(&buf[0], 30 - 2);
904             buf[2] = 0x70;
905             buf[3] = 0;
906             buf[4] = 0;
907             buf[5] = 0;
908             buf[6] = 0;
909             buf[7] = 0;
910 
911             buf[8] = MODE_PAGE_CAPABILITIES;
912             buf[9] = 30 - 10;
913             buf[10] = 0x3b; /* read CDR/CDRW/DVDROM/DVDR/DVDRAM */
914             buf[11] = 0x00;
915 
916             /* Claim PLAY_AUDIO capability (0x01) since some Linux
917                code checks for this to automount media. */
918             buf[12] = 0x71;
919             buf[13] = 3 << 5;
920             buf[14] = (1 << 0) | (1 << 3) | (1 << 5);
921             if (s->tray_locked) {
922                 buf[14] |= 1 << 1;
923             }
924             buf[15] = 0x00; /* No volume & mute control, no changer */
925             stw_be_p(&buf[16], 704); /* 4x read speed */
926             buf[18] = 0; /* Two volume levels */
927             buf[19] = 2;
928             stw_be_p(&buf[20], 512); /* 512k buffer */
929             stw_be_p(&buf[22], 704); /* 4x read speed current */
930             buf[24] = 0;
931             buf[25] = 0;
932             buf[26] = 0;
933             buf[27] = 0;
934             buf[28] = 0;
935             buf[29] = 0;
936             ide_atapi_cmd_reply(s, 30, max_len);
937             break;
938         default:
939             goto error_cmd;
940         }
941         break;
942     case 1: /* changeable values */
943         goto error_cmd;
944     case 2: /* default values */
945         goto error_cmd;
946     default:
947     case 3: /* saved values */
948         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
949                             ASC_SAVING_PARAMETERS_NOT_SUPPORTED);
950         break;
951     }
952     return;
953 
954 error_cmd:
955     ide_atapi_cmd_error(s, ILLEGAL_REQUEST, ASC_INV_FIELD_IN_CMD_PACKET);
956 }
957 
958 static void cmd_test_unit_ready(IDEState *s, uint8_t *buf)
959 {
960     /* Not Ready Conditions are already handled in ide_atapi_cmd(), so if we
961      * come here, we know that it's ready. */
962     ide_atapi_cmd_ok(s);
963 }
964 
965 static void cmd_prevent_allow_medium_removal(IDEState *s, uint8_t* buf)
966 {
967     s->tray_locked = buf[4] & 1;
968     blk_lock_medium(s->blk, buf[4] & 1);
969     ide_atapi_cmd_ok(s);
970 }
971 
972 static void cmd_read(IDEState *s, uint8_t* buf)
973 {
974     int nb_sectors, lba;
975 
976     if (buf[0] == GPCMD_READ_10) {
977         nb_sectors = lduw_be_p(buf + 7);
978     } else {
979         nb_sectors = ldl_be_p(buf + 6);
980     }
981 
982     lba = ldl_be_p(buf + 2);
983     if (nb_sectors == 0) {
984         ide_atapi_cmd_ok(s);
985         return;
986     }
987 
988     ide_atapi_cmd_read(s, lba, nb_sectors, 2048);
989 }
990 
991 static void cmd_read_cd(IDEState *s, uint8_t* buf)
992 {
993     int nb_sectors, lba, transfer_request;
994 
995     nb_sectors = (buf[6] << 16) | (buf[7] << 8) | buf[8];
996     lba = ldl_be_p(buf + 2);
997 
998     if (nb_sectors == 0) {
999         ide_atapi_cmd_ok(s);
1000         return;
1001     }
1002 
1003     transfer_request = buf[9] & 0xf8;
1004     if (transfer_request == 0x00) {
1005         /* nothing */
1006         ide_atapi_cmd_ok(s);
1007         return;
1008     }
1009 
1010     /* Check validity of BCL before transferring data */
1011     if (!validate_bcl(s)) {
1012         return;
1013     }
1014 
1015     switch (transfer_request) {
1016     case 0x10:
1017         /* normal read */
1018         ide_atapi_cmd_read(s, lba, nb_sectors, 2048);
1019         break;
1020     case 0xf8:
1021         /* read all data */
1022         ide_atapi_cmd_read(s, lba, nb_sectors, 2352);
1023         break;
1024     default:
1025         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1026                             ASC_INV_FIELD_IN_CMD_PACKET);
1027         break;
1028     }
1029 }
1030 
1031 static void cmd_seek(IDEState *s, uint8_t* buf)
1032 {
1033     unsigned int lba;
1034     uint64_t total_sectors = s->nb_sectors >> 2;
1035 
1036     lba = ldl_be_p(buf + 2);
1037     if (lba >= total_sectors) {
1038         ide_atapi_cmd_error(s, ILLEGAL_REQUEST, ASC_LOGICAL_BLOCK_OOR);
1039         return;
1040     }
1041 
1042     ide_atapi_cmd_ok(s);
1043 }
1044 
1045 static void cmd_start_stop_unit(IDEState *s, uint8_t* buf)
1046 {
1047     int sense;
1048     bool start = buf[4] & 1;
1049     bool loej = buf[4] & 2;     /* load on start, eject on !start */
1050     int pwrcnd = buf[4] & 0xf0;
1051 
1052     if (pwrcnd) {
1053         /* eject/load only happens for power condition == 0 */
1054         ide_atapi_cmd_ok(s);
1055         return;
1056     }
1057 
1058     if (loej) {
1059         if (!start && !s->tray_open && s->tray_locked) {
1060             sense = blk_is_inserted(s->blk)
1061                 ? NOT_READY : ILLEGAL_REQUEST;
1062             ide_atapi_cmd_error(s, sense, ASC_MEDIA_REMOVAL_PREVENTED);
1063             return;
1064         }
1065 
1066         if (s->tray_open != !start) {
1067             blk_eject(s->blk, !start);
1068             s->tray_open = !start;
1069         }
1070     }
1071 
1072     ide_atapi_cmd_ok(s);
1073 }
1074 
1075 static void cmd_mechanism_status(IDEState *s, uint8_t* buf)
1076 {
1077     int max_len = lduw_be_p(buf + 8);
1078 
1079     stw_be_p(buf, 0);
1080     /* no current LBA */
1081     buf[2] = 0;
1082     buf[3] = 0;
1083     buf[4] = 0;
1084     buf[5] = 1;
1085     stw_be_p(buf + 6, 0);
1086     ide_atapi_cmd_reply(s, 8, max_len);
1087 }
1088 
1089 static void cmd_read_toc_pma_atip(IDEState *s, uint8_t* buf)
1090 {
1091     int format, msf, start_track, len;
1092     int max_len;
1093     uint64_t total_sectors = s->nb_sectors >> 2;
1094 
1095     max_len = lduw_be_p(buf + 7);
1096     format = buf[9] >> 6;
1097     msf = (buf[1] >> 1) & 1;
1098     start_track = buf[6];
1099 
1100     switch(format) {
1101     case 0:
1102         len = cdrom_read_toc(total_sectors, buf, msf, start_track);
1103         if (len < 0)
1104             goto error_cmd;
1105         ide_atapi_cmd_reply(s, len, max_len);
1106         break;
1107     case 1:
1108         /* multi session : only a single session defined */
1109         memset(buf, 0, 12);
1110         buf[1] = 0x0a;
1111         buf[2] = 0x01;
1112         buf[3] = 0x01;
1113         ide_atapi_cmd_reply(s, 12, max_len);
1114         break;
1115     case 2:
1116         len = cdrom_read_toc_raw(total_sectors, buf, msf, start_track);
1117         if (len < 0)
1118             goto error_cmd;
1119         ide_atapi_cmd_reply(s, len, max_len);
1120         break;
1121     default:
1122     error_cmd:
1123         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1124                             ASC_INV_FIELD_IN_CMD_PACKET);
1125     }
1126 }
1127 
1128 static void cmd_read_cdvd_capacity(IDEState *s, uint8_t* buf)
1129 {
1130     uint64_t total_sectors = s->nb_sectors >> 2;
1131 
1132     /* NOTE: it is really the number of sectors minus 1 */
1133     stl_be_p(buf, total_sectors - 1);
1134     stl_be_p(buf + 4, 2048);
1135     ide_atapi_cmd_reply(s, 8, 8);
1136 }
1137 
1138 static void cmd_read_disc_information(IDEState *s, uint8_t* buf)
1139 {
1140     uint8_t type = buf[1] & 7;
1141     uint32_t max_len = lduw_be_p(buf + 7);
1142 
1143     /* Types 1/2 are only defined for Blu-Ray.  */
1144     if (type != 0) {
1145         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1146                             ASC_INV_FIELD_IN_CMD_PACKET);
1147         return;
1148     }
1149 
1150     memset(buf, 0, 34);
1151     buf[1] = 32;
1152     buf[2] = 0xe; /* last session complete, disc finalized */
1153     buf[3] = 1;   /* first track on disc */
1154     buf[4] = 1;   /* # of sessions */
1155     buf[5] = 1;   /* first track of last session */
1156     buf[6] = 1;   /* last track of last session */
1157     buf[7] = 0x20; /* unrestricted use */
1158     buf[8] = 0x00; /* CD-ROM or DVD-ROM */
1159     /* 9-10-11: most significant byte corresponding bytes 4-5-6 */
1160     /* 12-23: not meaningful for CD-ROM or DVD-ROM */
1161     /* 24-31: disc bar code */
1162     /* 32: disc application code */
1163     /* 33: number of OPC tables */
1164 
1165     ide_atapi_cmd_reply(s, 34, max_len);
1166 }
1167 
1168 static void cmd_read_dvd_structure(IDEState *s, uint8_t* buf)
1169 {
1170     int max_len;
1171     int media = buf[1];
1172     int format = buf[7];
1173     int ret;
1174 
1175     max_len = lduw_be_p(buf + 8);
1176 
1177     if (format < 0xff) {
1178         if (media_is_cd(s)) {
1179             ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1180                                 ASC_INCOMPATIBLE_FORMAT);
1181             return;
1182         } else if (!media_present(s)) {
1183             ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1184                                 ASC_INV_FIELD_IN_CMD_PACKET);
1185             return;
1186         }
1187     }
1188 
1189     memset(buf, 0, max_len > IDE_DMA_BUF_SECTORS * BDRV_SECTOR_SIZE + 4 ?
1190            IDE_DMA_BUF_SECTORS * BDRV_SECTOR_SIZE + 4 : max_len);
1191 
1192     switch (format) {
1193         case 0x00 ... 0x7f:
1194         case 0xff:
1195             if (media == 0) {
1196                 ret = ide_dvd_read_structure(s, format, buf, buf);
1197 
1198                 if (ret < 0) {
1199                     ide_atapi_cmd_error(s, ILLEGAL_REQUEST, -ret);
1200                 } else {
1201                     ide_atapi_cmd_reply(s, ret, max_len);
1202                 }
1203 
1204                 break;
1205             }
1206             /* TODO: BD support, fall through for now */
1207 
1208         /* Generic disk structures */
1209         case 0x80: /* TODO: AACS volume identifier */
1210         case 0x81: /* TODO: AACS media serial number */
1211         case 0x82: /* TODO: AACS media identifier */
1212         case 0x83: /* TODO: AACS media key block */
1213         case 0x90: /* TODO: List of recognized format layers */
1214         case 0xc0: /* TODO: Write protection status */
1215         default:
1216             ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1217                                 ASC_INV_FIELD_IN_CMD_PACKET);
1218             break;
1219     }
1220 }
1221 
1222 static void cmd_set_speed(IDEState *s, uint8_t* buf)
1223 {
1224     ide_atapi_cmd_ok(s);
1225 }
1226 
1227 enum {
1228     /*
1229      * Only commands flagged as ALLOW_UA are allowed to run under a
1230      * unit attention condition. (See MMC-5, section 4.1.6.1)
1231      */
1232     ALLOW_UA = 0x01,
1233 
1234     /*
1235      * Commands flagged with CHECK_READY can only execute if a medium is present.
1236      * Otherwise they report the Not Ready Condition. (See MMC-5, section
1237      * 4.1.8)
1238      */
1239     CHECK_READY = 0x02,
1240 
1241     /*
1242      * Commands flagged with NONDATA do not in any circumstances return
1243      * any data via ide_atapi_cmd_reply. These commands are exempt from
1244      * the normal byte_count_limit constraints.
1245      * See ATA8-ACS3 "7.21.5 Byte Count Limit"
1246      */
1247     NONDATA = 0x04,
1248 
1249     /*
1250      * CONDDATA implies a command that transfers data only conditionally based
1251      * on the presence of suboptions. It should be exempt from the BCL check at
1252      * command validation time, but it needs to be checked at the command
1253      * handler level instead.
1254      */
1255     CONDDATA = 0x08,
1256 };
1257 
1258 static const struct AtapiCmd {
1259     void (*handler)(IDEState *s, uint8_t *buf);
1260     int flags;
1261 } atapi_cmd_table[0x100] = {
1262     [ 0x00 ] = { cmd_test_unit_ready,               CHECK_READY | NONDATA },
1263     [ 0x03 ] = { cmd_request_sense,                 ALLOW_UA },
1264     [ 0x12 ] = { cmd_inquiry,                       ALLOW_UA },
1265     [ 0x1b ] = { cmd_start_stop_unit,               NONDATA }, /* [1] */
1266     [ 0x1e ] = { cmd_prevent_allow_medium_removal,  NONDATA },
1267     [ 0x25 ] = { cmd_read_cdvd_capacity,            CHECK_READY },
1268     [ 0x28 ] = { cmd_read, /* (10) */               CHECK_READY },
1269     [ 0x2b ] = { cmd_seek,                          CHECK_READY | NONDATA },
1270     [ 0x43 ] = { cmd_read_toc_pma_atip,             CHECK_READY },
1271     [ 0x46 ] = { cmd_get_configuration,             ALLOW_UA },
1272     [ 0x4a ] = { cmd_get_event_status_notification, ALLOW_UA },
1273     [ 0x51 ] = { cmd_read_disc_information,         CHECK_READY },
1274     [ 0x5a ] = { cmd_mode_sense, /* (10) */         0 },
1275     [ 0xa8 ] = { cmd_read, /* (12) */               CHECK_READY },
1276     [ 0xad ] = { cmd_read_dvd_structure,            CHECK_READY },
1277     [ 0xbb ] = { cmd_set_speed,                     NONDATA },
1278     [ 0xbd ] = { cmd_mechanism_status,              0 },
1279     [ 0xbe ] = { cmd_read_cd,                       CHECK_READY | CONDDATA },
1280     /* [1] handler detects and reports not ready condition itself */
1281 };
1282 
1283 void ide_atapi_cmd(IDEState *s)
1284 {
1285     uint8_t *buf = s->io_buffer;
1286     const struct AtapiCmd *cmd = &atapi_cmd_table[s->io_buffer[0]];
1287 
1288     trace_ide_atapi_cmd(s, s->io_buffer[0]);
1289 
1290     if (trace_event_get_state_backends(TRACE_IDE_ATAPI_CMD_PACKET)) {
1291         /* Each pretty-printed byte needs two bytes and a space; */
1292         char *ppacket = g_malloc(ATAPI_PACKET_SIZE * 3 + 1);
1293         int i;
1294         for (i = 0; i < ATAPI_PACKET_SIZE; i++) {
1295             sprintf(ppacket + (i * 3), "%02x ", buf[i]);
1296         }
1297         trace_ide_atapi_cmd_packet(s, s->lcyl | (s->hcyl << 8), ppacket);
1298         g_free(ppacket);
1299     }
1300 
1301     /*
1302      * If there's a UNIT_ATTENTION condition pending, only command flagged with
1303      * ALLOW_UA are allowed to complete. with other commands getting a CHECK
1304      * condition response unless a higher priority status, defined by the drive
1305      * here, is pending.
1306      */
1307     if (s->sense_key == UNIT_ATTENTION && !(cmd->flags & ALLOW_UA)) {
1308         ide_atapi_cmd_check_status(s);
1309         return;
1310     }
1311     /*
1312      * When a CD gets changed, we have to report an ejected state and
1313      * then a loaded state to guests so that they detect tray
1314      * open/close and media change events.  Guests that do not use
1315      * GET_EVENT_STATUS_NOTIFICATION to detect such tray open/close
1316      * states rely on this behavior.
1317      */
1318     if (!(cmd->flags & ALLOW_UA) &&
1319         !s->tray_open && blk_is_inserted(s->blk) && s->cdrom_changed) {
1320 
1321         if (s->cdrom_changed == 1) {
1322             ide_atapi_cmd_error(s, NOT_READY, ASC_MEDIUM_NOT_PRESENT);
1323             s->cdrom_changed = 2;
1324         } else {
1325             ide_atapi_cmd_error(s, UNIT_ATTENTION, ASC_MEDIUM_MAY_HAVE_CHANGED);
1326             s->cdrom_changed = 0;
1327         }
1328 
1329         return;
1330     }
1331 
1332     /* Report a Not Ready condition if appropriate for the command */
1333     if ((cmd->flags & CHECK_READY) &&
1334         (!media_present(s) || !blk_is_inserted(s->blk)))
1335     {
1336         ide_atapi_cmd_error(s, NOT_READY, ASC_MEDIUM_NOT_PRESENT);
1337         return;
1338     }
1339 
1340     /* Commands that don't transfer DATA permit the byte_count_limit to be 0.
1341      * If this is a data-transferring PIO command and BCL is 0,
1342      * we abort at the /ATA/ level, not the ATAPI level.
1343      * See ATA8 ACS3 section 7.17.6.49 and 7.21.5 */
1344     if (cmd->handler && !(cmd->flags & (NONDATA | CONDDATA))) {
1345         if (!validate_bcl(s)) {
1346             return;
1347         }
1348     }
1349 
1350     /* Execute the command */
1351     if (cmd->handler) {
1352         cmd->handler(s, buf);
1353         return;
1354     }
1355 
1356     ide_atapi_cmd_error(s, ILLEGAL_REQUEST, ASC_ILLEGAL_OPCODE);
1357 }
1358