xref: /openbmc/qemu/hw/ide/atapi.c (revision c63ca4ff)
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         assert(size <= s->io_buffer_total_len);
280         assert(s->io_buffer_index <= s->io_buffer_total_len);
281 
282         /* Some adapters process PIO data right away.  In that case, we need
283          * to avoid mutual recursion between ide_transfer_start
284          * and ide_atapi_cmd_reply_end.
285          */
286         if (!ide_transfer_start_norecurse(s,
287                                           s->io_buffer + s->io_buffer_index - size,
288                                           size, ide_atapi_cmd_reply_end)) {
289             return;
290         }
291     }
292 
293     /* end of transfer */
294     trace_ide_atapi_cmd_reply_end_eot(s, s->status);
295     ide_atapi_cmd_ok(s);
296     ide_set_irq(s->bus);
297 }
298 
299 /* send a reply of 'size' bytes in s->io_buffer to an ATAPI command */
300 static void ide_atapi_cmd_reply(IDEState *s, int size, int max_size)
301 {
302     if (size > max_size)
303         size = max_size;
304     s->lba = -1; /* no sector read */
305     s->packet_transfer_size = size;
306     s->io_buffer_size = size;    /* dma: send the reply data as one chunk */
307     s->elementary_transfer_size = 0;
308 
309     if (s->atapi_dma) {
310         block_acct_start(blk_get_stats(s->blk), &s->acct, size,
311                          BLOCK_ACCT_READ);
312         s->status = READY_STAT | SEEK_STAT | DRQ_STAT;
313         ide_start_dma(s, ide_atapi_cmd_read_dma_cb);
314     } else {
315         s->status = READY_STAT | SEEK_STAT;
316         s->io_buffer_index = 0;
317         ide_atapi_cmd_reply_end(s);
318     }
319 }
320 
321 /* start a CD-CDROM read command */
322 static void ide_atapi_cmd_read_pio(IDEState *s, int lba, int nb_sectors,
323                                    int sector_size)
324 {
325     s->lba = lba;
326     s->packet_transfer_size = nb_sectors * sector_size;
327     s->elementary_transfer_size = 0;
328     s->io_buffer_index = sector_size;
329     s->cd_sector_size = sector_size;
330 
331     ide_atapi_cmd_reply_end(s);
332 }
333 
334 static void ide_atapi_cmd_check_status(IDEState *s)
335 {
336     trace_ide_atapi_cmd_check_status(s);
337     s->error = MC_ERR | (UNIT_ATTENTION << 4);
338     s->status = ERR_STAT;
339     s->nsector = 0;
340     ide_set_irq(s->bus);
341 }
342 /* ATAPI DMA support */
343 
344 static void ide_atapi_cmd_read_dma_cb(void *opaque, int ret)
345 {
346     IDEState *s = opaque;
347     int data_offset, n;
348 
349     if (ret < 0) {
350         if (ide_handle_rw_error(s, -ret, ide_dma_cmd_to_retry(s->dma_cmd))) {
351             if (s->bus->error_status) {
352                 s->bus->dma->aiocb = NULL;
353                 return;
354             }
355             goto eot;
356         }
357     }
358 
359     if (s->io_buffer_size > 0) {
360         /*
361          * For a cdrom read sector command (s->lba != -1),
362          * adjust the lba for the next s->io_buffer_size chunk
363          * and dma the current chunk.
364          * For a command != read (s->lba == -1), just transfer
365          * the reply data.
366          */
367         if (s->lba != -1) {
368             if (s->cd_sector_size == 2352) {
369                 n = 1;
370                 cd_data_to_raw(s->io_buffer, s->lba);
371             } else {
372                 n = s->io_buffer_size >> 11;
373             }
374             s->lba += n;
375         }
376         s->packet_transfer_size -= s->io_buffer_size;
377         if (s->bus->dma->ops->rw_buf(s->bus->dma, 1) == 0)
378             goto eot;
379     }
380 
381     if (s->packet_transfer_size <= 0) {
382         s->status = READY_STAT | SEEK_STAT;
383         s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;
384         ide_set_irq(s->bus);
385         goto eot;
386     }
387 
388     s->io_buffer_index = 0;
389     if (s->cd_sector_size == 2352) {
390         n = 1;
391         s->io_buffer_size = s->cd_sector_size;
392         data_offset = 16;
393     } else {
394         n = s->packet_transfer_size >> 11;
395         if (n > (IDE_DMA_BUF_SECTORS / 4))
396             n = (IDE_DMA_BUF_SECTORS / 4);
397         s->io_buffer_size = n * 2048;
398         data_offset = 0;
399     }
400     trace_ide_atapi_cmd_read_dma_cb_aio(s, s->lba, n);
401     qemu_iovec_init_buf(&s->bus->dma->qiov, s->io_buffer + data_offset,
402                         n * ATAPI_SECTOR_SIZE);
403 
404     s->bus->dma->aiocb = ide_buffered_readv(s, (int64_t)s->lba << 2,
405                                             &s->bus->dma->qiov, n * 4,
406                                             ide_atapi_cmd_read_dma_cb, s);
407     return;
408 
409 eot:
410     if (ret < 0) {
411         block_acct_failed(blk_get_stats(s->blk), &s->acct);
412     } else {
413         block_acct_done(blk_get_stats(s->blk), &s->acct);
414     }
415     ide_set_inactive(s, false);
416 }
417 
418 /* start a CD-CDROM read command with DMA */
419 /* XXX: test if DMA is available */
420 static void ide_atapi_cmd_read_dma(IDEState *s, int lba, int nb_sectors,
421                                    int sector_size)
422 {
423     s->lba = lba;
424     s->packet_transfer_size = nb_sectors * sector_size;
425     s->io_buffer_size = 0;
426     s->cd_sector_size = sector_size;
427 
428     block_acct_start(blk_get_stats(s->blk), &s->acct, s->packet_transfer_size,
429                      BLOCK_ACCT_READ);
430 
431     /* XXX: check if BUSY_STAT should be set */
432     s->status = READY_STAT | SEEK_STAT | DRQ_STAT | BUSY_STAT;
433     ide_start_dma(s, ide_atapi_cmd_read_dma_cb);
434 }
435 
436 static void ide_atapi_cmd_read(IDEState *s, int lba, int nb_sectors,
437                                int sector_size)
438 {
439     trace_ide_atapi_cmd_read(s, s->atapi_dma ? "dma" : "pio",
440                              lba, nb_sectors);
441     if (s->atapi_dma) {
442         ide_atapi_cmd_read_dma(s, lba, nb_sectors, sector_size);
443     } else {
444         ide_atapi_cmd_read_pio(s, lba, nb_sectors, sector_size);
445     }
446 }
447 
448 void ide_atapi_dma_restart(IDEState *s)
449 {
450     /*
451      * At this point we can just re-evaluate the packet command and start over.
452      * The presence of ->dma_cb callback in the pre_save ensures that the packet
453      * command has been completely sent and we can safely restart command.
454      */
455     s->unit = s->bus->retry_unit;
456     s->bus->dma->ops->restart_dma(s->bus->dma);
457     ide_atapi_cmd(s);
458 }
459 
460 static inline uint8_t ide_atapi_set_profile(uint8_t *buf, uint8_t *index,
461                                             uint16_t profile)
462 {
463     uint8_t *buf_profile = buf + 12; /* start of profiles */
464 
465     buf_profile += ((*index) * 4); /* start of indexed profile */
466     stw_be_p(buf_profile, profile);
467     buf_profile[2] = ((buf_profile[0] == buf[6]) && (buf_profile[1] == buf[7]));
468 
469     /* each profile adds 4 bytes to the response */
470     (*index)++;
471     buf[11] += 4; /* Additional Length */
472 
473     return 4;
474 }
475 
476 static int ide_dvd_read_structure(IDEState *s, int format,
477                                   const uint8_t *packet, uint8_t *buf)
478 {
479     switch (format) {
480         case 0x0: /* Physical format information */
481             {
482                 int layer = packet[6];
483                 uint64_t total_sectors;
484 
485                 if (layer != 0)
486                     return -ASC_INV_FIELD_IN_CMD_PACKET;
487 
488                 total_sectors = s->nb_sectors >> 2;
489                 if (total_sectors == 0) {
490                     return -ASC_MEDIUM_NOT_PRESENT;
491                 }
492 
493                 buf[4] = 1;   /* DVD-ROM, part version 1 */
494                 buf[5] = 0xf; /* 120mm disc, minimum rate unspecified */
495                 buf[6] = 1;   /* one layer, read-only (per MMC-2 spec) */
496                 buf[7] = 0;   /* default densities */
497 
498                 /* FIXME: 0x30000 per spec? */
499                 stl_be_p(buf + 8, 0); /* start sector */
500                 stl_be_p(buf + 12, total_sectors - 1); /* end sector */
501                 stl_be_p(buf + 16, total_sectors - 1); /* l0 end sector */
502 
503                 /* Size of buffer, not including 2 byte size field */
504                 stw_be_p(buf, 2048 + 2);
505 
506                 /* 2k data + 4 byte header */
507                 return (2048 + 4);
508             }
509 
510         case 0x01: /* DVD copyright information */
511             buf[4] = 0; /* no copyright data */
512             buf[5] = 0; /* no region restrictions */
513 
514             /* Size of buffer, not including 2 byte size field */
515             stw_be_p(buf, 4 + 2);
516 
517             /* 4 byte header + 4 byte data */
518             return (4 + 4);
519 
520         case 0x03: /* BCA information - invalid field for no BCA info */
521             return -ASC_INV_FIELD_IN_CMD_PACKET;
522 
523         case 0x04: /* DVD disc manufacturing information */
524             /* Size of buffer, not including 2 byte size field */
525             stw_be_p(buf, 2048 + 2);
526 
527             /* 2k data + 4 byte header */
528             return (2048 + 4);
529 
530         case 0xff:
531             /*
532              * This lists all the command capabilities above.  Add new ones
533              * in order and update the length and buffer return values.
534              */
535 
536             buf[4] = 0x00; /* Physical format */
537             buf[5] = 0x40; /* Not writable, is readable */
538             stw_be_p(buf + 6, 2048 + 4);
539 
540             buf[8] = 0x01; /* Copyright info */
541             buf[9] = 0x40; /* Not writable, is readable */
542             stw_be_p(buf + 10, 4 + 4);
543 
544             buf[12] = 0x03; /* BCA info */
545             buf[13] = 0x40; /* Not writable, is readable */
546             stw_be_p(buf + 14, 188 + 4);
547 
548             buf[16] = 0x04; /* Manufacturing info */
549             buf[17] = 0x40; /* Not writable, is readable */
550             stw_be_p(buf + 18, 2048 + 4);
551 
552             /* Size of buffer, not including 2 byte size field */
553             stw_be_p(buf, 16 + 2);
554 
555             /* data written + 4 byte header */
556             return (16 + 4);
557 
558         default: /* TODO: formats beyond DVD-ROM requires */
559             return -ASC_INV_FIELD_IN_CMD_PACKET;
560     }
561 }
562 
563 static unsigned int event_status_media(IDEState *s,
564                                        uint8_t *buf)
565 {
566     uint8_t event_code, media_status;
567 
568     media_status = 0;
569     if (s->tray_open) {
570         media_status = MS_TRAY_OPEN;
571     } else if (blk_is_inserted(s->blk)) {
572         media_status = MS_MEDIA_PRESENT;
573     }
574 
575     /* Event notification descriptor */
576     event_code = MEC_NO_CHANGE;
577     if (media_status != MS_TRAY_OPEN) {
578         if (s->events.new_media) {
579             event_code = MEC_NEW_MEDIA;
580             s->events.new_media = false;
581         } else if (s->events.eject_request) {
582             event_code = MEC_EJECT_REQUESTED;
583             s->events.eject_request = false;
584         }
585     }
586 
587     buf[4] = event_code;
588     buf[5] = media_status;
589 
590     /* These fields are reserved, just clear them. */
591     buf[6] = 0;
592     buf[7] = 0;
593 
594     return 8; /* We wrote to 4 extra bytes from the header */
595 }
596 
597 /*
598  * Before transferring data or otherwise signalling acceptance of a command
599  * marked CONDDATA, we must check the validity of the byte_count_limit.
600  */
601 static bool validate_bcl(IDEState *s)
602 {
603     /* TODO: Check IDENTIFY data word 125 for defacult BCL (currently 0) */
604     if (s->atapi_dma || atapi_byte_count_limit(s)) {
605         return true;
606     }
607 
608     /* TODO: Move abort back into core.c and introduce proper error flow between
609      *       ATAPI layer and IDE core layer */
610     ide_abort_command(s);
611     return false;
612 }
613 
614 static void cmd_get_event_status_notification(IDEState *s,
615                                               uint8_t *buf)
616 {
617     const uint8_t *packet = buf;
618 
619     struct {
620         uint8_t opcode;
621         uint8_t polled;        /* lsb bit is polled; others are reserved */
622         uint8_t reserved2[2];
623         uint8_t class;
624         uint8_t reserved3[2];
625         uint16_t len;
626         uint8_t control;
627     } QEMU_PACKED *gesn_cdb;
628 
629     struct {
630         uint16_t len;
631         uint8_t notification_class;
632         uint8_t supported_events;
633     } QEMU_PACKED *gesn_event_header;
634     unsigned int max_len, used_len;
635 
636     gesn_cdb = (void *)packet;
637     gesn_event_header = (void *)buf;
638 
639     max_len = be16_to_cpu(gesn_cdb->len);
640 
641     /* It is fine by the MMC spec to not support async mode operations */
642     if (!(gesn_cdb->polled & 0x01)) { /* asynchronous mode */
643         /* Only polling is supported, asynchronous mode is not. */
644         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
645                             ASC_INV_FIELD_IN_CMD_PACKET);
646         return;
647     }
648 
649     /* polling mode operation */
650 
651     /*
652      * These are the supported events.
653      *
654      * We currently only support requests of the 'media' type.
655      * Notification class requests and supported event classes are bitmasks,
656      * but they are build from the same values as the "notification class"
657      * field.
658      */
659     gesn_event_header->supported_events = 1 << GESN_MEDIA;
660 
661     /*
662      * We use |= below to set the class field; other bits in this byte
663      * are reserved now but this is useful to do if we have to use the
664      * reserved fields later.
665      */
666     gesn_event_header->notification_class = 0;
667 
668     /*
669      * Responses to requests are to be based on request priority.  The
670      * notification_class_request_type enum above specifies the
671      * priority: upper elements are higher prio than lower ones.
672      */
673     if (gesn_cdb->class & (1 << GESN_MEDIA)) {
674         gesn_event_header->notification_class |= GESN_MEDIA;
675         used_len = event_status_media(s, buf);
676     } else {
677         gesn_event_header->notification_class = 0x80; /* No event available */
678         used_len = sizeof(*gesn_event_header);
679     }
680     gesn_event_header->len = cpu_to_be16(used_len
681                                          - sizeof(*gesn_event_header));
682     ide_atapi_cmd_reply(s, used_len, max_len);
683 }
684 
685 static void cmd_request_sense(IDEState *s, uint8_t *buf)
686 {
687     int max_len = buf[4];
688 
689     memset(buf, 0, 18);
690     buf[0] = 0x70 | (1 << 7);
691     buf[2] = s->sense_key;
692     buf[7] = 10;
693     buf[12] = s->asc;
694 
695     if (s->sense_key == UNIT_ATTENTION) {
696         s->sense_key = NO_SENSE;
697     }
698 
699     ide_atapi_cmd_reply(s, 18, max_len);
700 }
701 
702 static void cmd_inquiry(IDEState *s, uint8_t *buf)
703 {
704     uint8_t page_code = buf[2];
705     int max_len = buf[4];
706 
707     unsigned idx = 0;
708     unsigned size_idx;
709     unsigned preamble_len;
710 
711     /* If the EVPD (Enable Vital Product Data) bit is set in byte 1,
712      * we are being asked for a specific page of info indicated by byte 2. */
713     if (buf[1] & 0x01) {
714         preamble_len = 4;
715         size_idx = 3;
716 
717         buf[idx++] = 0x05;      /* CD-ROM */
718         buf[idx++] = page_code; /* Page Code */
719         buf[idx++] = 0x00;      /* reserved */
720         idx++;                  /* length (set later) */
721 
722         switch (page_code) {
723         case 0x00:
724             /* Supported Pages: List of supported VPD responses. */
725             buf[idx++] = 0x00; /* 0x00: Supported Pages, and: */
726             buf[idx++] = 0x83; /* 0x83: Device Identification. */
727             break;
728 
729         case 0x83:
730             /* Device Identification. Each entry is optional, but the entries
731              * included here are modeled after libata's VPD responses.
732              * If the response is given, at least one entry must be present. */
733 
734             /* Entry 1: Serial */
735             if (idx + 24 > max_len) {
736                 /* Not enough room for even the first entry: */
737                 /* 4 byte header + 20 byte string */
738                 ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
739                                     ASC_DATA_PHASE_ERROR);
740                 return;
741             }
742             buf[idx++] = 0x02; /* Ascii */
743             buf[idx++] = 0x00; /* Vendor Specific */
744             buf[idx++] = 0x00;
745             buf[idx++] = 20;   /* Remaining length */
746             padstr8(buf + idx, 20, s->drive_serial_str);
747             idx += 20;
748 
749             /* Entry 2: Drive Model and Serial */
750             if (idx + 72 > max_len) {
751                 /* 4 (header) + 8 (vendor) + 60 (model & serial) */
752                 goto out;
753             }
754             buf[idx++] = 0x02; /* Ascii */
755             buf[idx++] = 0x01; /* T10 Vendor */
756             buf[idx++] = 0x00;
757             buf[idx++] = 68;
758             padstr8(buf + idx, 8, "ATA"); /* Generic T10 vendor */
759             idx += 8;
760             padstr8(buf + idx, 40, s->drive_model_str);
761             idx += 40;
762             padstr8(buf + idx, 20, s->drive_serial_str);
763             idx += 20;
764 
765             /* Entry 3: WWN */
766             if (s->wwn && (idx + 12 <= max_len)) {
767                 /* 4 byte header + 8 byte wwn */
768                 buf[idx++] = 0x01; /* Binary */
769                 buf[idx++] = 0x03; /* NAA */
770                 buf[idx++] = 0x00;
771                 buf[idx++] = 0x08;
772                 stq_be_p(&buf[idx], s->wwn);
773                 idx += 8;
774             }
775             break;
776 
777         default:
778             /* SPC-3, revision 23 sec. 6.4 */
779             ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
780                                 ASC_INV_FIELD_IN_CMD_PACKET);
781             return;
782         }
783     } else {
784         preamble_len = 5;
785         size_idx = 4;
786 
787         buf[0] = 0x05; /* CD-ROM */
788         buf[1] = 0x80; /* removable */
789         buf[2] = 0x00; /* ISO */
790         buf[3] = 0x21; /* ATAPI-2 (XXX: put ATAPI-4 ?) */
791         /* buf[size_idx] set below. */
792         buf[5] = 0;    /* reserved */
793         buf[6] = 0;    /* reserved */
794         buf[7] = 0;    /* reserved */
795         padstr8(buf + 8, 8, "QEMU");
796         padstr8(buf + 16, 16, "QEMU DVD-ROM");
797         padstr8(buf + 32, 4, s->version);
798         idx = 36;
799     }
800 
801  out:
802     buf[size_idx] = idx - preamble_len;
803     ide_atapi_cmd_reply(s, idx, max_len);
804 }
805 
806 static void cmd_get_configuration(IDEState *s, uint8_t *buf)
807 {
808     uint32_t len;
809     uint8_t index = 0;
810     int max_len;
811 
812     /* only feature 0 is supported */
813     if (buf[2] != 0 || buf[3] != 0) {
814         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
815                             ASC_INV_FIELD_IN_CMD_PACKET);
816         return;
817     }
818 
819     /* XXX: could result in alignment problems in some architectures */
820     max_len = lduw_be_p(buf + 7);
821 
822     /*
823      * XXX: avoid overflow for io_buffer if max_len is bigger than
824      *      the size of that buffer (dimensioned to max number of
825      *      sectors to transfer at once)
826      *
827      *      Only a problem if the feature/profiles grow.
828      */
829     if (max_len > BDRV_SECTOR_SIZE) {
830         /* XXX: assume 1 sector */
831         max_len = BDRV_SECTOR_SIZE;
832     }
833 
834     memset(buf, 0, max_len);
835     /*
836      * the number of sectors from the media tells us which profile
837      * to use as current.  0 means there is no media
838      */
839     if (media_is_dvd(s)) {
840         stw_be_p(buf + 6, MMC_PROFILE_DVD_ROM);
841     } else if (media_is_cd(s)) {
842         stw_be_p(buf + 6, MMC_PROFILE_CD_ROM);
843     }
844 
845     buf[10] = 0x02 | 0x01; /* persistent and current */
846     len = 12; /* headers: 8 + 4 */
847     len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_DVD_ROM);
848     len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_CD_ROM);
849     stl_be_p(buf, len - 4); /* data length */
850 
851     ide_atapi_cmd_reply(s, len, max_len);
852 }
853 
854 static void cmd_mode_sense(IDEState *s, uint8_t *buf)
855 {
856     int action, code;
857     int max_len;
858 
859     max_len = lduw_be_p(buf + 7);
860     action = buf[2] >> 6;
861     code = buf[2] & 0x3f;
862 
863     switch(action) {
864     case 0: /* current values */
865         switch(code) {
866         case MODE_PAGE_R_W_ERROR: /* error recovery */
867             stw_be_p(&buf[0], 16 - 2);
868             buf[2] = 0x70;
869             buf[3] = 0;
870             buf[4] = 0;
871             buf[5] = 0;
872             buf[6] = 0;
873             buf[7] = 0;
874 
875             buf[8] = MODE_PAGE_R_W_ERROR;
876             buf[9] = 16 - 10;
877             buf[10] = 0x00;
878             buf[11] = 0x05;
879             buf[12] = 0x00;
880             buf[13] = 0x00;
881             buf[14] = 0x00;
882             buf[15] = 0x00;
883             ide_atapi_cmd_reply(s, 16, max_len);
884             break;
885         case MODE_PAGE_AUDIO_CTL:
886             stw_be_p(&buf[0], 24 - 2);
887             buf[2] = 0x70;
888             buf[3] = 0;
889             buf[4] = 0;
890             buf[5] = 0;
891             buf[6] = 0;
892             buf[7] = 0;
893 
894             buf[8] = MODE_PAGE_AUDIO_CTL;
895             buf[9] = 24 - 10;
896             /* Fill with CDROM audio volume */
897             buf[17] = 0;
898             buf[19] = 0;
899             buf[21] = 0;
900             buf[23] = 0;
901 
902             ide_atapi_cmd_reply(s, 24, max_len);
903             break;
904         case MODE_PAGE_CAPABILITIES:
905             stw_be_p(&buf[0], 30 - 2);
906             buf[2] = 0x70;
907             buf[3] = 0;
908             buf[4] = 0;
909             buf[5] = 0;
910             buf[6] = 0;
911             buf[7] = 0;
912 
913             buf[8] = MODE_PAGE_CAPABILITIES;
914             buf[9] = 30 - 10;
915             buf[10] = 0x3b; /* read CDR/CDRW/DVDROM/DVDR/DVDRAM */
916             buf[11] = 0x00;
917 
918             /* Claim PLAY_AUDIO capability (0x01) since some Linux
919                code checks for this to automount media. */
920             buf[12] = 0x71;
921             buf[13] = 3 << 5;
922             buf[14] = (1 << 0) | (1 << 3) | (1 << 5);
923             if (s->tray_locked) {
924                 buf[14] |= 1 << 1;
925             }
926             buf[15] = 0x00; /* No volume & mute control, no changer */
927             stw_be_p(&buf[16], 704); /* 4x read speed */
928             buf[18] = 0; /* Two volume levels */
929             buf[19] = 2;
930             stw_be_p(&buf[20], 512); /* 512k buffer */
931             stw_be_p(&buf[22], 704); /* 4x read speed current */
932             buf[24] = 0;
933             buf[25] = 0;
934             buf[26] = 0;
935             buf[27] = 0;
936             buf[28] = 0;
937             buf[29] = 0;
938             ide_atapi_cmd_reply(s, 30, max_len);
939             break;
940         default:
941             goto error_cmd;
942         }
943         break;
944     case 1: /* changeable values */
945         goto error_cmd;
946     case 2: /* default values */
947         goto error_cmd;
948     default:
949     case 3: /* saved values */
950         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
951                             ASC_SAVING_PARAMETERS_NOT_SUPPORTED);
952         break;
953     }
954     return;
955 
956 error_cmd:
957     ide_atapi_cmd_error(s, ILLEGAL_REQUEST, ASC_INV_FIELD_IN_CMD_PACKET);
958 }
959 
960 static void cmd_test_unit_ready(IDEState *s, uint8_t *buf)
961 {
962     /* Not Ready Conditions are already handled in ide_atapi_cmd(), so if we
963      * come here, we know that it's ready. */
964     ide_atapi_cmd_ok(s);
965 }
966 
967 static void cmd_prevent_allow_medium_removal(IDEState *s, uint8_t* buf)
968 {
969     s->tray_locked = buf[4] & 1;
970     blk_lock_medium(s->blk, buf[4] & 1);
971     ide_atapi_cmd_ok(s);
972 }
973 
974 static void cmd_read(IDEState *s, uint8_t* buf)
975 {
976     int nb_sectors, lba;
977 
978     if (buf[0] == GPCMD_READ_10) {
979         nb_sectors = lduw_be_p(buf + 7);
980     } else {
981         nb_sectors = ldl_be_p(buf + 6);
982     }
983 
984     lba = ldl_be_p(buf + 2);
985     if (nb_sectors == 0) {
986         ide_atapi_cmd_ok(s);
987         return;
988     }
989 
990     ide_atapi_cmd_read(s, lba, nb_sectors, 2048);
991 }
992 
993 static void cmd_read_cd(IDEState *s, uint8_t* buf)
994 {
995     int nb_sectors, lba, transfer_request;
996 
997     nb_sectors = (buf[6] << 16) | (buf[7] << 8) | buf[8];
998     lba = ldl_be_p(buf + 2);
999 
1000     if (nb_sectors == 0) {
1001         ide_atapi_cmd_ok(s);
1002         return;
1003     }
1004 
1005     transfer_request = buf[9] & 0xf8;
1006     if (transfer_request == 0x00) {
1007         /* nothing */
1008         ide_atapi_cmd_ok(s);
1009         return;
1010     }
1011 
1012     /* Check validity of BCL before transferring data */
1013     if (!validate_bcl(s)) {
1014         return;
1015     }
1016 
1017     switch (transfer_request) {
1018     case 0x10:
1019         /* normal read */
1020         ide_atapi_cmd_read(s, lba, nb_sectors, 2048);
1021         break;
1022     case 0xf8:
1023         /* read all data */
1024         ide_atapi_cmd_read(s, lba, nb_sectors, 2352);
1025         break;
1026     default:
1027         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1028                             ASC_INV_FIELD_IN_CMD_PACKET);
1029         break;
1030     }
1031 }
1032 
1033 static void cmd_seek(IDEState *s, uint8_t* buf)
1034 {
1035     unsigned int lba;
1036     uint64_t total_sectors = s->nb_sectors >> 2;
1037 
1038     lba = ldl_be_p(buf + 2);
1039     if (lba >= total_sectors) {
1040         ide_atapi_cmd_error(s, ILLEGAL_REQUEST, ASC_LOGICAL_BLOCK_OOR);
1041         return;
1042     }
1043 
1044     ide_atapi_cmd_ok(s);
1045 }
1046 
1047 static void cmd_start_stop_unit(IDEState *s, uint8_t* buf)
1048 {
1049     int sense;
1050     bool start = buf[4] & 1;
1051     bool loej = buf[4] & 2;     /* load on start, eject on !start */
1052     int pwrcnd = buf[4] & 0xf0;
1053 
1054     if (pwrcnd) {
1055         /* eject/load only happens for power condition == 0 */
1056         ide_atapi_cmd_ok(s);
1057         return;
1058     }
1059 
1060     if (loej) {
1061         if (!start && !s->tray_open && s->tray_locked) {
1062             sense = blk_is_inserted(s->blk)
1063                 ? NOT_READY : ILLEGAL_REQUEST;
1064             ide_atapi_cmd_error(s, sense, ASC_MEDIA_REMOVAL_PREVENTED);
1065             return;
1066         }
1067 
1068         if (s->tray_open != !start) {
1069             blk_eject(s->blk, !start);
1070             s->tray_open = !start;
1071         }
1072     }
1073 
1074     ide_atapi_cmd_ok(s);
1075 }
1076 
1077 static void cmd_mechanism_status(IDEState *s, uint8_t* buf)
1078 {
1079     int max_len = lduw_be_p(buf + 8);
1080 
1081     stw_be_p(buf, 0);
1082     /* no current LBA */
1083     buf[2] = 0;
1084     buf[3] = 0;
1085     buf[4] = 0;
1086     buf[5] = 1;
1087     stw_be_p(buf + 6, 0);
1088     ide_atapi_cmd_reply(s, 8, max_len);
1089 }
1090 
1091 static void cmd_read_toc_pma_atip(IDEState *s, uint8_t* buf)
1092 {
1093     int format, msf, start_track, len;
1094     int max_len;
1095     uint64_t total_sectors = s->nb_sectors >> 2;
1096 
1097     max_len = lduw_be_p(buf + 7);
1098     format = buf[9] >> 6;
1099     msf = (buf[1] >> 1) & 1;
1100     start_track = buf[6];
1101 
1102     switch(format) {
1103     case 0:
1104         len = cdrom_read_toc(total_sectors, buf, msf, start_track);
1105         if (len < 0)
1106             goto error_cmd;
1107         ide_atapi_cmd_reply(s, len, max_len);
1108         break;
1109     case 1:
1110         /* multi session : only a single session defined */
1111         memset(buf, 0, 12);
1112         buf[1] = 0x0a;
1113         buf[2] = 0x01;
1114         buf[3] = 0x01;
1115         ide_atapi_cmd_reply(s, 12, max_len);
1116         break;
1117     case 2:
1118         len = cdrom_read_toc_raw(total_sectors, buf, msf, start_track);
1119         if (len < 0)
1120             goto error_cmd;
1121         ide_atapi_cmd_reply(s, len, max_len);
1122         break;
1123     default:
1124     error_cmd:
1125         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1126                             ASC_INV_FIELD_IN_CMD_PACKET);
1127     }
1128 }
1129 
1130 static void cmd_read_cdvd_capacity(IDEState *s, uint8_t* buf)
1131 {
1132     uint64_t total_sectors = s->nb_sectors >> 2;
1133 
1134     /* NOTE: it is really the number of sectors minus 1 */
1135     stl_be_p(buf, total_sectors - 1);
1136     stl_be_p(buf + 4, 2048);
1137     ide_atapi_cmd_reply(s, 8, 8);
1138 }
1139 
1140 static void cmd_read_disc_information(IDEState *s, uint8_t* buf)
1141 {
1142     uint8_t type = buf[1] & 7;
1143     uint32_t max_len = lduw_be_p(buf + 7);
1144 
1145     /* Types 1/2 are only defined for Blu-Ray.  */
1146     if (type != 0) {
1147         ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1148                             ASC_INV_FIELD_IN_CMD_PACKET);
1149         return;
1150     }
1151 
1152     memset(buf, 0, 34);
1153     buf[1] = 32;
1154     buf[2] = 0xe; /* last session complete, disc finalized */
1155     buf[3] = 1;   /* first track on disc */
1156     buf[4] = 1;   /* # of sessions */
1157     buf[5] = 1;   /* first track of last session */
1158     buf[6] = 1;   /* last track of last session */
1159     buf[7] = 0x20; /* unrestricted use */
1160     buf[8] = 0x00; /* CD-ROM or DVD-ROM */
1161     /* 9-10-11: most significant byte corresponding bytes 4-5-6 */
1162     /* 12-23: not meaningful for CD-ROM or DVD-ROM */
1163     /* 24-31: disc bar code */
1164     /* 32: disc application code */
1165     /* 33: number of OPC tables */
1166 
1167     ide_atapi_cmd_reply(s, 34, max_len);
1168 }
1169 
1170 static void cmd_read_dvd_structure(IDEState *s, uint8_t* buf)
1171 {
1172     int max_len;
1173     int media = buf[1];
1174     int format = buf[7];
1175     int ret;
1176 
1177     max_len = lduw_be_p(buf + 8);
1178 
1179     if (format < 0xff) {
1180         if (media_is_cd(s)) {
1181             ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1182                                 ASC_INCOMPATIBLE_FORMAT);
1183             return;
1184         } else if (!media_present(s)) {
1185             ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1186                                 ASC_INV_FIELD_IN_CMD_PACKET);
1187             return;
1188         }
1189     }
1190 
1191     memset(buf, 0, max_len > IDE_DMA_BUF_SECTORS * BDRV_SECTOR_SIZE + 4 ?
1192            IDE_DMA_BUF_SECTORS * BDRV_SECTOR_SIZE + 4 : max_len);
1193 
1194     switch (format) {
1195         case 0x00 ... 0x7f:
1196         case 0xff:
1197             if (media == 0) {
1198                 ret = ide_dvd_read_structure(s, format, buf, buf);
1199 
1200                 if (ret < 0) {
1201                     ide_atapi_cmd_error(s, ILLEGAL_REQUEST, -ret);
1202                 } else {
1203                     ide_atapi_cmd_reply(s, ret, max_len);
1204                 }
1205 
1206                 break;
1207             }
1208             /* TODO: BD support, fall through for now */
1209 
1210         /* Generic disk structures */
1211         case 0x80: /* TODO: AACS volume identifier */
1212         case 0x81: /* TODO: AACS media serial number */
1213         case 0x82: /* TODO: AACS media identifier */
1214         case 0x83: /* TODO: AACS media key block */
1215         case 0x90: /* TODO: List of recognized format layers */
1216         case 0xc0: /* TODO: Write protection status */
1217         default:
1218             ide_atapi_cmd_error(s, ILLEGAL_REQUEST,
1219                                 ASC_INV_FIELD_IN_CMD_PACKET);
1220             break;
1221     }
1222 }
1223 
1224 static void cmd_set_speed(IDEState *s, uint8_t* buf)
1225 {
1226     ide_atapi_cmd_ok(s);
1227 }
1228 
1229 enum {
1230     /*
1231      * Only commands flagged as ALLOW_UA are allowed to run under a
1232      * unit attention condition. (See MMC-5, section 4.1.6.1)
1233      */
1234     ALLOW_UA = 0x01,
1235 
1236     /*
1237      * Commands flagged with CHECK_READY can only execute if a medium is present.
1238      * Otherwise they report the Not Ready Condition. (See MMC-5, section
1239      * 4.1.8)
1240      */
1241     CHECK_READY = 0x02,
1242 
1243     /*
1244      * Commands flagged with NONDATA do not in any circumstances return
1245      * any data via ide_atapi_cmd_reply. These commands are exempt from
1246      * the normal byte_count_limit constraints.
1247      * See ATA8-ACS3 "7.21.5 Byte Count Limit"
1248      */
1249     NONDATA = 0x04,
1250 
1251     /*
1252      * CONDDATA implies a command that transfers data only conditionally based
1253      * on the presence of suboptions. It should be exempt from the BCL check at
1254      * command validation time, but it needs to be checked at the command
1255      * handler level instead.
1256      */
1257     CONDDATA = 0x08,
1258 };
1259 
1260 static const struct AtapiCmd {
1261     void (*handler)(IDEState *s, uint8_t *buf);
1262     int flags;
1263 } atapi_cmd_table[0x100] = {
1264     [ 0x00 ] = { cmd_test_unit_ready,               CHECK_READY | NONDATA },
1265     [ 0x03 ] = { cmd_request_sense,                 ALLOW_UA },
1266     [ 0x12 ] = { cmd_inquiry,                       ALLOW_UA },
1267     [ 0x1b ] = { cmd_start_stop_unit,               NONDATA }, /* [1] */
1268     [ 0x1e ] = { cmd_prevent_allow_medium_removal,  NONDATA },
1269     [ 0x25 ] = { cmd_read_cdvd_capacity,            CHECK_READY },
1270     [ 0x28 ] = { cmd_read, /* (10) */               CHECK_READY },
1271     [ 0x2b ] = { cmd_seek,                          CHECK_READY | NONDATA },
1272     [ 0x43 ] = { cmd_read_toc_pma_atip,             CHECK_READY },
1273     [ 0x46 ] = { cmd_get_configuration,             ALLOW_UA },
1274     [ 0x4a ] = { cmd_get_event_status_notification, ALLOW_UA },
1275     [ 0x51 ] = { cmd_read_disc_information,         CHECK_READY },
1276     [ 0x5a ] = { cmd_mode_sense, /* (10) */         0 },
1277     [ 0xa8 ] = { cmd_read, /* (12) */               CHECK_READY },
1278     [ 0xad ] = { cmd_read_dvd_structure,            CHECK_READY },
1279     [ 0xbb ] = { cmd_set_speed,                     NONDATA },
1280     [ 0xbd ] = { cmd_mechanism_status,              0 },
1281     [ 0xbe ] = { cmd_read_cd,                       CHECK_READY | CONDDATA },
1282     /* [1] handler detects and reports not ready condition itself */
1283 };
1284 
1285 void ide_atapi_cmd(IDEState *s)
1286 {
1287     uint8_t *buf = s->io_buffer;
1288     const struct AtapiCmd *cmd = &atapi_cmd_table[s->io_buffer[0]];
1289 
1290     trace_ide_atapi_cmd(s, s->io_buffer[0]);
1291 
1292     if (trace_event_get_state_backends(TRACE_IDE_ATAPI_CMD_PACKET)) {
1293         /* Each pretty-printed byte needs two bytes and a space; */
1294         char *ppacket = g_malloc(ATAPI_PACKET_SIZE * 3 + 1);
1295         int i;
1296         for (i = 0; i < ATAPI_PACKET_SIZE; i++) {
1297             sprintf(ppacket + (i * 3), "%02x ", buf[i]);
1298         }
1299         trace_ide_atapi_cmd_packet(s, s->lcyl | (s->hcyl << 8), ppacket);
1300         g_free(ppacket);
1301     }
1302 
1303     /*
1304      * If there's a UNIT_ATTENTION condition pending, only command flagged with
1305      * ALLOW_UA are allowed to complete. with other commands getting a CHECK
1306      * condition response unless a higher priority status, defined by the drive
1307      * here, is pending.
1308      */
1309     if (s->sense_key == UNIT_ATTENTION && !(cmd->flags & ALLOW_UA)) {
1310         ide_atapi_cmd_check_status(s);
1311         return;
1312     }
1313     /*
1314      * When a CD gets changed, we have to report an ejected state and
1315      * then a loaded state to guests so that they detect tray
1316      * open/close and media change events.  Guests that do not use
1317      * GET_EVENT_STATUS_NOTIFICATION to detect such tray open/close
1318      * states rely on this behavior.
1319      */
1320     if (!(cmd->flags & ALLOW_UA) &&
1321         !s->tray_open && blk_is_inserted(s->blk) && s->cdrom_changed) {
1322 
1323         if (s->cdrom_changed == 1) {
1324             ide_atapi_cmd_error(s, NOT_READY, ASC_MEDIUM_NOT_PRESENT);
1325             s->cdrom_changed = 2;
1326         } else {
1327             ide_atapi_cmd_error(s, UNIT_ATTENTION, ASC_MEDIUM_MAY_HAVE_CHANGED);
1328             s->cdrom_changed = 0;
1329         }
1330 
1331         return;
1332     }
1333 
1334     /* Report a Not Ready condition if appropriate for the command */
1335     if ((cmd->flags & CHECK_READY) &&
1336         (!media_present(s) || !blk_is_inserted(s->blk)))
1337     {
1338         ide_atapi_cmd_error(s, NOT_READY, ASC_MEDIUM_NOT_PRESENT);
1339         return;
1340     }
1341 
1342     /* Commands that don't transfer DATA permit the byte_count_limit to be 0.
1343      * If this is a data-transferring PIO command and BCL is 0,
1344      * we abort at the /ATA/ level, not the ATAPI level.
1345      * See ATA8 ACS3 section 7.17.6.49 and 7.21.5 */
1346     if (cmd->handler && !(cmd->flags & (NONDATA | CONDDATA))) {
1347         if (!validate_bcl(s)) {
1348             return;
1349         }
1350     }
1351 
1352     /* Execute the command */
1353     if (cmd->handler) {
1354         cmd->handler(s, buf);
1355         return;
1356     }
1357 
1358     ide_atapi_cmd_error(s, ILLEGAL_REQUEST, ASC_ILLEGAL_OPCODE);
1359 }
1360