xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision 0fbb5d2d)
1 #include "qemu/osdep.h"
2 #include "qapi/error.h"
3 #include "qemu/error-report.h"
4 #include "qemu/module.h"
5 #include "qemu/option.h"
6 #include "hw/qdev-properties.h"
7 #include "hw/scsi/scsi.h"
8 #include "migration/qemu-file-types.h"
9 #include "migration/vmstate.h"
10 #include "scsi/constants.h"
11 #include "sysemu/block-backend.h"
12 #include "sysemu/blockdev.h"
13 #include "sysemu/sysemu.h"
14 #include "sysemu/runstate.h"
15 #include "trace.h"
16 #include "sysemu/dma.h"
17 #include "qemu/cutils.h"
18 
19 static char *scsibus_get_dev_path(DeviceState *dev);
20 static char *scsibus_get_fw_dev_path(DeviceState *dev);
21 static void scsi_req_dequeue(SCSIRequest *req);
22 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len);
23 static void scsi_target_free_buf(SCSIRequest *req);
24 
25 static int next_scsi_bus;
26 
27 static SCSIDevice *do_scsi_device_find(SCSIBus *bus,
28                                        int channel, int id, int lun,
29                                        bool include_unrealized)
30 {
31     BusChild *kid;
32     SCSIDevice *retval = NULL;
33 
34     QTAILQ_FOREACH_RCU(kid, &bus->qbus.children, sibling) {
35         DeviceState *qdev = kid->child;
36         SCSIDevice *dev = SCSI_DEVICE(qdev);
37 
38         if (dev->channel == channel && dev->id == id) {
39             if (dev->lun == lun) {
40                 retval = dev;
41                 break;
42             }
43 
44             /*
45              * If we don't find exact match (channel/bus/lun),
46              * we will return the first device which matches channel/bus
47              */
48 
49             if (!retval) {
50                 retval = dev;
51             }
52         }
53     }
54 
55     /*
56      * This function might run on the IO thread and we might race against
57      * main thread hot-plugging the device.
58      * We assume that as soon as .realized is set to true we can let
59      * the user access the device.
60      */
61 
62     if (retval && !include_unrealized &&
63         !qatomic_load_acquire(&retval->qdev.realized)) {
64         retval = NULL;
65     }
66 
67     return retval;
68 }
69 
70 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
71 {
72     RCU_READ_LOCK_GUARD();
73     return do_scsi_device_find(bus, channel, id, lun, false);
74 }
75 
76 SCSIDevice *scsi_device_get(SCSIBus *bus, int channel, int id, int lun)
77 {
78     SCSIDevice *d;
79     RCU_READ_LOCK_GUARD();
80     d = do_scsi_device_find(bus, channel, id, lun, false);
81     if (d) {
82         object_ref(d);
83     }
84     return d;
85 }
86 
87 static void scsi_device_realize(SCSIDevice *s, Error **errp)
88 {
89     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
90     if (sc->realize) {
91         sc->realize(s, errp);
92     }
93 }
94 
95 static void scsi_device_unrealize(SCSIDevice *s)
96 {
97     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
98     if (sc->unrealize) {
99         sc->unrealize(s);
100     }
101 }
102 
103 int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
104                        void *hba_private)
105 {
106     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
107     int rc;
108 
109     assert(cmd->len == 0);
110     rc = scsi_req_parse_cdb(dev, cmd, buf);
111     if (bus->info->parse_cdb) {
112         rc = bus->info->parse_cdb(dev, cmd, buf, hba_private);
113     }
114     return rc;
115 }
116 
117 static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
118                                           uint8_t *buf, void *hba_private)
119 {
120     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
121     if (sc->alloc_req) {
122         return sc->alloc_req(s, tag, lun, buf, hba_private);
123     }
124 
125     return NULL;
126 }
127 
128 void scsi_device_unit_attention_reported(SCSIDevice *s)
129 {
130     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
131     if (sc->unit_attention_reported) {
132         sc->unit_attention_reported(s);
133     }
134 }
135 
136 /* Create a scsi bus, and attach devices to it.  */
137 void scsi_bus_init_named(SCSIBus *bus, size_t bus_size, DeviceState *host,
138                          const SCSIBusInfo *info, const char *bus_name)
139 {
140     qbus_init(bus, bus_size, TYPE_SCSI_BUS, host, bus_name);
141     bus->busnr = next_scsi_bus++;
142     bus->info = info;
143     qbus_set_bus_hotplug_handler(BUS(bus));
144 }
145 
146 static void scsi_dma_restart_bh(void *opaque)
147 {
148     SCSIDevice *s = opaque;
149     SCSIRequest *req, *next;
150 
151     qemu_bh_delete(s->bh);
152     s->bh = NULL;
153 
154     aio_context_acquire(blk_get_aio_context(s->conf.blk));
155     QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
156         scsi_req_ref(req);
157         if (req->retry) {
158             req->retry = false;
159             switch (req->cmd.mode) {
160             case SCSI_XFER_FROM_DEV:
161             case SCSI_XFER_TO_DEV:
162                 scsi_req_continue(req);
163                 break;
164             case SCSI_XFER_NONE:
165                 scsi_req_dequeue(req);
166                 scsi_req_enqueue(req);
167                 break;
168             }
169         }
170         scsi_req_unref(req);
171     }
172     aio_context_release(blk_get_aio_context(s->conf.blk));
173     /* Drop the reference that was acquired in scsi_dma_restart_cb */
174     object_unref(OBJECT(s));
175 }
176 
177 void scsi_req_retry(SCSIRequest *req)
178 {
179     /* No need to save a reference, because scsi_dma_restart_bh just
180      * looks at the request list.  */
181     req->retry = true;
182 }
183 
184 static void scsi_dma_restart_cb(void *opaque, bool running, RunState state)
185 {
186     SCSIDevice *s = opaque;
187 
188     if (!running) {
189         return;
190     }
191     if (!s->bh) {
192         AioContext *ctx = blk_get_aio_context(s->conf.blk);
193         /* The reference is dropped in scsi_dma_restart_bh.*/
194         object_ref(OBJECT(s));
195         s->bh = aio_bh_new(ctx, scsi_dma_restart_bh, s);
196         qemu_bh_schedule(s->bh);
197     }
198 }
199 
200 static bool scsi_bus_is_address_free(SCSIBus *bus,
201 				     int channel, int target, int lun,
202 				     SCSIDevice **p_dev)
203 {
204     SCSIDevice *d;
205 
206     RCU_READ_LOCK_GUARD();
207     d = do_scsi_device_find(bus, channel, target, lun, true);
208     if (d && d->lun == lun) {
209         if (p_dev) {
210             *p_dev = d;
211         }
212         return false;
213     }
214     if (p_dev) {
215         *p_dev = NULL;
216     }
217     return true;
218 }
219 
220 static bool scsi_bus_check_address(BusState *qbus, DeviceState *qdev, Error **errp)
221 {
222     SCSIDevice *dev = SCSI_DEVICE(qdev);
223     SCSIBus *bus = SCSI_BUS(qbus);
224 
225     if (dev->channel > bus->info->max_channel) {
226         error_setg(errp, "bad scsi channel id: %d", dev->channel);
227         return false;
228     }
229     if (dev->id != -1 && dev->id > bus->info->max_target) {
230         error_setg(errp, "bad scsi device id: %d", dev->id);
231         return false;
232     }
233     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
234         error_setg(errp, "bad scsi device lun: %d", dev->lun);
235         return false;
236     }
237 
238     if (dev->id != -1 && dev->lun != -1) {
239         SCSIDevice *d;
240         if (!scsi_bus_is_address_free(bus, dev->channel, dev->id, dev->lun, &d)) {
241             error_setg(errp, "lun already used by '%s'", d->qdev.id);
242             return false;
243         }
244     }
245 
246     return true;
247 }
248 
249 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
250 {
251     SCSIDevice *dev = SCSI_DEVICE(qdev);
252     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
253     bool is_free;
254     Error *local_err = NULL;
255 
256     if (dev->id == -1) {
257         int id = -1;
258         if (dev->lun == -1) {
259             dev->lun = 0;
260         }
261         do {
262             is_free = scsi_bus_is_address_free(bus, dev->channel, ++id, dev->lun, NULL);
263         } while (!is_free && id < bus->info->max_target);
264         if (!is_free) {
265             error_setg(errp, "no free target");
266             return;
267         }
268         dev->id = id;
269     } else if (dev->lun == -1) {
270         int lun = -1;
271         do {
272             is_free = scsi_bus_is_address_free(bus, dev->channel, dev->id, ++lun, NULL);
273         } while (!is_free && lun < bus->info->max_lun);
274         if (!is_free) {
275             error_setg(errp, "no free lun");
276             return;
277         }
278         dev->lun = lun;
279     }
280 
281     QTAILQ_INIT(&dev->requests);
282     scsi_device_realize(dev, &local_err);
283     if (local_err) {
284         error_propagate(errp, local_err);
285         return;
286     }
287     dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
288             scsi_dma_restart_cb, dev);
289 }
290 
291 static void scsi_qdev_unrealize(DeviceState *qdev)
292 {
293     SCSIDevice *dev = SCSI_DEVICE(qdev);
294 
295     if (dev->vmsentry) {
296         qemu_del_vm_change_state_handler(dev->vmsentry);
297     }
298 
299     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
300 
301     scsi_device_unrealize(dev);
302 
303     blockdev_mark_auto_del(dev->conf.blk);
304 }
305 
306 /* handle legacy '-drive if=scsi,...' cmd line args */
307 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
308                                       int unit, bool removable, int bootindex,
309                                       bool share_rw,
310                                       BlockdevOnError rerror,
311                                       BlockdevOnError werror,
312                                       const char *serial, Error **errp)
313 {
314     const char *driver;
315     char *name;
316     DeviceState *dev;
317     DriveInfo *dinfo;
318 
319     if (blk_is_sg(blk)) {
320         driver = "scsi-generic";
321     } else {
322         dinfo = blk_legacy_dinfo(blk);
323         if (dinfo && dinfo->media_cd) {
324             driver = "scsi-cd";
325         } else {
326             driver = "scsi-hd";
327         }
328     }
329     dev = qdev_new(driver);
330     name = g_strdup_printf("legacy[%d]", unit);
331     object_property_add_child(OBJECT(bus), name, OBJECT(dev));
332     g_free(name);
333 
334     qdev_prop_set_uint32(dev, "scsi-id", unit);
335     if (bootindex >= 0) {
336         object_property_set_int(OBJECT(dev), "bootindex", bootindex,
337                                 &error_abort);
338     }
339     if (object_property_find(OBJECT(dev), "removable")) {
340         qdev_prop_set_bit(dev, "removable", removable);
341     }
342     if (serial && object_property_find(OBJECT(dev), "serial")) {
343         qdev_prop_set_string(dev, "serial", serial);
344     }
345     if (!qdev_prop_set_drive_err(dev, "drive", blk, errp)) {
346         object_unparent(OBJECT(dev));
347         return NULL;
348     }
349     if (!object_property_set_bool(OBJECT(dev), "share-rw", share_rw, errp)) {
350         object_unparent(OBJECT(dev));
351         return NULL;
352     }
353 
354     qdev_prop_set_enum(dev, "rerror", rerror);
355     qdev_prop_set_enum(dev, "werror", werror);
356 
357     if (!qdev_realize_and_unref(dev, &bus->qbus, errp)) {
358         object_unparent(OBJECT(dev));
359         return NULL;
360     }
361     return SCSI_DEVICE(dev);
362 }
363 
364 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
365 {
366     Location loc;
367     DriveInfo *dinfo;
368     int unit;
369 
370     loc_push_none(&loc);
371     for (unit = 0; unit <= bus->info->max_target; unit++) {
372         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
373         if (dinfo == NULL) {
374             continue;
375         }
376         qemu_opts_loc_restore(dinfo->opts);
377         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
378                                   unit, false, -1, false,
379                                   BLOCKDEV_ON_ERROR_AUTO,
380                                   BLOCKDEV_ON_ERROR_AUTO,
381                                   NULL, &error_fatal);
382     }
383     loc_pop(&loc);
384 }
385 
386 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
387 {
388     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
389     scsi_req_complete(req, CHECK_CONDITION);
390     return 0;
391 }
392 
393 static const struct SCSIReqOps reqops_invalid_field = {
394     .size         = sizeof(SCSIRequest),
395     .send_command = scsi_invalid_field
396 };
397 
398 /* SCSIReqOps implementation for invalid commands.  */
399 
400 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
401 {
402     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
403     scsi_req_complete(req, CHECK_CONDITION);
404     return 0;
405 }
406 
407 static const struct SCSIReqOps reqops_invalid_opcode = {
408     .size         = sizeof(SCSIRequest),
409     .send_command = scsi_invalid_command
410 };
411 
412 /* SCSIReqOps implementation for unit attention conditions.  */
413 
414 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
415 {
416     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
417         scsi_req_build_sense(req, req->dev->unit_attention);
418     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
419         scsi_req_build_sense(req, req->bus->unit_attention);
420     }
421     scsi_req_complete(req, CHECK_CONDITION);
422     return 0;
423 }
424 
425 static const struct SCSIReqOps reqops_unit_attention = {
426     .size         = sizeof(SCSIRequest),
427     .send_command = scsi_unit_attention
428 };
429 
430 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
431    an invalid LUN.  */
432 
433 typedef struct SCSITargetReq SCSITargetReq;
434 
435 struct SCSITargetReq {
436     SCSIRequest req;
437     int len;
438     uint8_t *buf;
439     int buf_len;
440 };
441 
442 static void store_lun(uint8_t *outbuf, int lun)
443 {
444     if (lun < 256) {
445         /* Simple logical unit addressing method*/
446         outbuf[0] = 0;
447         outbuf[1] = lun;
448     } else {
449         /* Flat space addressing method */
450         outbuf[0] = 0x40 | (lun >> 8);
451         outbuf[1] = (lun & 255);
452     }
453 }
454 
455 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
456 {
457     BusChild *kid;
458     int channel, id;
459     uint8_t tmp[8] = {0};
460     int len = 0;
461     GByteArray *buf;
462 
463     if (r->req.cmd.xfer < 16) {
464         return false;
465     }
466     if (r->req.cmd.buf[2] > 2) {
467         return false;
468     }
469 
470     /* reserve space for 63 LUNs*/
471     buf = g_byte_array_sized_new(512);
472 
473     channel = r->req.dev->channel;
474     id = r->req.dev->id;
475 
476     /* add size (will be updated later to correct value */
477     g_byte_array_append(buf, tmp, 8);
478     len += 8;
479 
480     /* add LUN0 */
481     g_byte_array_append(buf, tmp, 8);
482     len += 8;
483 
484     WITH_RCU_READ_LOCK_GUARD() {
485         QTAILQ_FOREACH_RCU(kid, &r->req.bus->qbus.children, sibling) {
486             DeviceState *qdev = kid->child;
487             SCSIDevice *dev = SCSI_DEVICE(qdev);
488 
489             if (dev->channel == channel && dev->id == id && dev->lun != 0) {
490                 store_lun(tmp, dev->lun);
491                 g_byte_array_append(buf, tmp, 8);
492                 len += 8;
493             }
494         }
495     }
496 
497     r->buf_len = len;
498     r->buf = g_byte_array_free(buf, FALSE);
499     r->len = MIN(len, r->req.cmd.xfer & ~7);
500 
501     /* store the LUN list length */
502     stl_be_p(&r->buf[0], len - 8);
503     return true;
504 }
505 
506 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
507 {
508     assert(r->req.dev->lun != r->req.lun);
509 
510     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
511 
512     if (r->req.cmd.buf[1] & 0x2) {
513         /* Command support data - optional, not implemented */
514         return false;
515     }
516 
517     if (r->req.cmd.buf[1] & 0x1) {
518         /* Vital product data */
519         uint8_t page_code = r->req.cmd.buf[2];
520         r->buf[r->len++] = page_code ; /* this page */
521         r->buf[r->len++] = 0x00;
522 
523         switch (page_code) {
524         case 0x00: /* Supported page codes, mandatory */
525         {
526             int pages;
527             pages = r->len++;
528             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
529             r->buf[pages] = r->len - pages - 1; /* number of pages */
530             break;
531         }
532         default:
533             return false;
534         }
535         /* done with EVPD */
536         assert(r->len < r->buf_len);
537         r->len = MIN(r->req.cmd.xfer, r->len);
538         return true;
539     }
540 
541     /* Standard INQUIRY data */
542     if (r->req.cmd.buf[2] != 0) {
543         return false;
544     }
545 
546     /* PAGE CODE == 0 */
547     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
548     memset(r->buf, 0, r->len);
549     if (r->req.lun != 0) {
550         r->buf[0] = TYPE_NO_LUN;
551     } else {
552         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
553         r->buf[2] = 5; /* Version */
554         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
555         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
556         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
557         memcpy(&r->buf[8], "QEMU    ", 8);
558         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
559         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
560     }
561     return true;
562 }
563 
564 static size_t scsi_sense_len(SCSIRequest *req)
565 {
566     if (req->dev->type == TYPE_SCANNER)
567         return SCSI_SENSE_LEN_SCANNER;
568     else
569         return SCSI_SENSE_LEN;
570 }
571 
572 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
573 {
574     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
575     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
576 
577     if (req->lun != 0 &&
578         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
579         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
580         scsi_req_complete(req, CHECK_CONDITION);
581         return 0;
582     }
583     switch (buf[0]) {
584     case REPORT_LUNS:
585         if (!scsi_target_emulate_report_luns(r)) {
586             goto illegal_request;
587         }
588         break;
589     case INQUIRY:
590         if (!scsi_target_emulate_inquiry(r)) {
591             goto illegal_request;
592         }
593         break;
594     case REQUEST_SENSE:
595         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
596         if (req->lun != 0) {
597             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
598 
599             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
600                                           sense, fixed_sense);
601         } else {
602             r->len = scsi_device_get_sense(r->req.dev, r->buf,
603                                            MIN(req->cmd.xfer, r->buf_len),
604                                            fixed_sense);
605         }
606         if (r->req.dev->sense_is_ua) {
607             scsi_device_unit_attention_reported(req->dev);
608             r->req.dev->sense_len = 0;
609             r->req.dev->sense_is_ua = false;
610         }
611         break;
612     case TEST_UNIT_READY:
613         break;
614     default:
615         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
616         scsi_req_complete(req, CHECK_CONDITION);
617         return 0;
618     illegal_request:
619         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
620         scsi_req_complete(req, CHECK_CONDITION);
621         return 0;
622     }
623 
624     if (!r->len) {
625         scsi_req_complete(req, GOOD);
626     }
627     return r->len;
628 }
629 
630 static void scsi_target_read_data(SCSIRequest *req)
631 {
632     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
633     uint32_t n;
634 
635     n = r->len;
636     if (n > 0) {
637         r->len = 0;
638         scsi_req_data(&r->req, n);
639     } else {
640         scsi_req_complete(&r->req, GOOD);
641     }
642 }
643 
644 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
645 {
646     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
647 
648     return r->buf;
649 }
650 
651 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
652 {
653     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
654 
655     r->buf = g_malloc(len);
656     r->buf_len = len;
657 
658     return r->buf;
659 }
660 
661 static void scsi_target_free_buf(SCSIRequest *req)
662 {
663     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
664 
665     g_free(r->buf);
666 }
667 
668 static const struct SCSIReqOps reqops_target_command = {
669     .size         = sizeof(SCSITargetReq),
670     .send_command = scsi_target_send_command,
671     .read_data    = scsi_target_read_data,
672     .get_buf      = scsi_target_get_buf,
673     .free_req     = scsi_target_free_buf,
674 };
675 
676 
677 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
678                             uint32_t tag, uint32_t lun, void *hba_private)
679 {
680     SCSIRequest *req;
681     SCSIBus *bus = scsi_bus_from_device(d);
682     BusState *qbus = BUS(bus);
683     const int memset_off = offsetof(SCSIRequest, sense)
684                            + sizeof(req->sense);
685 
686     req = g_malloc(reqops->size);
687     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
688     req->refcount = 1;
689     req->bus = bus;
690     req->dev = d;
691     req->tag = tag;
692     req->lun = lun;
693     req->hba_private = hba_private;
694     req->status = -1;
695     req->host_status = -1;
696     req->ops = reqops;
697     object_ref(OBJECT(d));
698     object_ref(OBJECT(qbus->parent));
699     notifier_list_init(&req->cancel_notifiers);
700     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
701     return req;
702 }
703 
704 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
705                           uint8_t *buf, void *hba_private)
706 {
707     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
708     const SCSIReqOps *ops;
709     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
710     SCSIRequest *req;
711     SCSICommand cmd = { .len = 0 };
712     int ret;
713 
714     if ((d->unit_attention.key == UNIT_ATTENTION ||
715          bus->unit_attention.key == UNIT_ATTENTION) &&
716         (buf[0] != INQUIRY &&
717          buf[0] != REPORT_LUNS &&
718          buf[0] != GET_CONFIGURATION &&
719          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
720 
721          /*
722           * If we already have a pending unit attention condition,
723           * report this one before triggering another one.
724           */
725          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
726         ops = &reqops_unit_attention;
727     } else if (lun != d->lun ||
728                buf[0] == REPORT_LUNS ||
729                (buf[0] == REQUEST_SENSE && d->sense_len)) {
730         ops = &reqops_target_command;
731     } else {
732         ops = NULL;
733     }
734 
735     if (ops != NULL || !sc->parse_cdb) {
736         ret = scsi_req_parse_cdb(d, &cmd, buf);
737     } else {
738         ret = sc->parse_cdb(d, &cmd, buf, hba_private);
739     }
740 
741     if (ret != 0) {
742         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
743         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
744     } else {
745         assert(cmd.len != 0);
746         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
747                               cmd.mode, cmd.xfer);
748         if (cmd.lba != -1) {
749             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
750                                       cmd.lba);
751         }
752 
753         if (cmd.xfer > INT32_MAX) {
754             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
755         } else if (ops) {
756             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
757         } else {
758             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
759         }
760     }
761 
762     req->cmd = cmd;
763     req->resid = req->cmd.xfer;
764 
765     switch (buf[0]) {
766     case INQUIRY:
767         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
768         break;
769     case TEST_UNIT_READY:
770         trace_scsi_test_unit_ready(d->id, lun, tag);
771         break;
772     case REPORT_LUNS:
773         trace_scsi_report_luns(d->id, lun, tag);
774         break;
775     case REQUEST_SENSE:
776         trace_scsi_request_sense(d->id, lun, tag);
777         break;
778     default:
779         break;
780     }
781 
782     return req;
783 }
784 
785 uint8_t *scsi_req_get_buf(SCSIRequest *req)
786 {
787     return req->ops->get_buf(req);
788 }
789 
790 static void scsi_clear_unit_attention(SCSIRequest *req)
791 {
792     SCSISense *ua;
793     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
794         req->bus->unit_attention.key != UNIT_ATTENTION) {
795         return;
796     }
797 
798     /*
799      * If an INQUIRY command enters the enabled command state,
800      * the device server shall [not] clear any unit attention condition;
801      * See also MMC-6, paragraphs 6.5 and 6.6.2.
802      */
803     if (req->cmd.buf[0] == INQUIRY ||
804         req->cmd.buf[0] == GET_CONFIGURATION ||
805         req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
806         return;
807     }
808 
809     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
810         ua = &req->dev->unit_attention;
811     } else {
812         ua = &req->bus->unit_attention;
813     }
814 
815     /*
816      * If a REPORT LUNS command enters the enabled command state, [...]
817      * the device server shall clear any pending unit attention condition
818      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
819      */
820     if (req->cmd.buf[0] == REPORT_LUNS &&
821         !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
822           ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
823         return;
824     }
825 
826     *ua = SENSE_CODE(NO_SENSE);
827 }
828 
829 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
830 {
831     int ret;
832 
833     assert(len >= 14);
834     if (!req->sense_len) {
835         return 0;
836     }
837 
838     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
839 
840     /*
841      * FIXME: clearing unit attention conditions upon autosense should be done
842      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
843      * (SAM-5, 5.14).
844      *
845      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
846      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
847      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
848      */
849     if (req->dev->sense_is_ua) {
850         scsi_device_unit_attention_reported(req->dev);
851         req->dev->sense_len = 0;
852         req->dev->sense_is_ua = false;
853     }
854     return ret;
855 }
856 
857 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
858 {
859     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
860 }
861 
862 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
863 {
864     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
865                                sense.key, sense.asc, sense.ascq);
866     req->sense_len = scsi_build_sense(req->sense, sense);
867 }
868 
869 static void scsi_req_enqueue_internal(SCSIRequest *req)
870 {
871     assert(!req->enqueued);
872     scsi_req_ref(req);
873     if (req->bus->info->get_sg_list) {
874         req->sg = req->bus->info->get_sg_list(req);
875     } else {
876         req->sg = NULL;
877     }
878     req->enqueued = true;
879     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
880 }
881 
882 int32_t scsi_req_enqueue(SCSIRequest *req)
883 {
884     int32_t rc;
885 
886     assert(!req->retry);
887     scsi_req_enqueue_internal(req);
888     scsi_req_ref(req);
889     rc = req->ops->send_command(req, req->cmd.buf);
890     scsi_req_unref(req);
891     return rc;
892 }
893 
894 static void scsi_req_dequeue(SCSIRequest *req)
895 {
896     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
897     req->retry = false;
898     if (req->enqueued) {
899         QTAILQ_REMOVE(&req->dev->requests, req, next);
900         req->enqueued = false;
901         scsi_req_unref(req);
902     }
903 }
904 
905 static int scsi_get_performance_length(int num_desc, int type, int data_type)
906 {
907     /* MMC-6, paragraph 6.7.  */
908     switch (type) {
909     case 0:
910         if ((data_type & 3) == 0) {
911             /* Each descriptor is as in Table 295 - Nominal performance.  */
912             return 16 * num_desc + 8;
913         } else {
914             /* Each descriptor is as in Table 296 - Exceptions.  */
915             return 6 * num_desc + 8;
916         }
917     case 1:
918     case 4:
919     case 5:
920         return 8 * num_desc + 8;
921     case 2:
922         return 2048 * num_desc + 8;
923     case 3:
924         return 16 * num_desc + 8;
925     default:
926         return 8;
927     }
928 }
929 
930 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
931 {
932     int byte_block = (buf[2] >> 2) & 0x1;
933     int type = (buf[2] >> 4) & 0x1;
934     int xfer_unit;
935 
936     if (byte_block) {
937         if (type) {
938             xfer_unit = dev->blocksize;
939         } else {
940             xfer_unit = 512;
941         }
942     } else {
943         xfer_unit = 1;
944     }
945 
946     return xfer_unit;
947 }
948 
949 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
950 {
951     int length = buf[2] & 0x3;
952     int xfer;
953     int unit = ata_passthrough_xfer_unit(dev, buf);
954 
955     switch (length) {
956     case 0:
957     case 3: /* USB-specific.  */
958     default:
959         xfer = 0;
960         break;
961     case 1:
962         xfer = buf[3];
963         break;
964     case 2:
965         xfer = buf[4];
966         break;
967     }
968 
969     return xfer * unit;
970 }
971 
972 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
973 {
974     int extend = buf[1] & 0x1;
975     int length = buf[2] & 0x3;
976     int xfer;
977     int unit = ata_passthrough_xfer_unit(dev, buf);
978 
979     switch (length) {
980     case 0:
981     case 3: /* USB-specific.  */
982     default:
983         xfer = 0;
984         break;
985     case 1:
986         xfer = buf[4];
987         xfer |= (extend ? buf[3] << 8 : 0);
988         break;
989     case 2:
990         xfer = buf[6];
991         xfer |= (extend ? buf[5] << 8 : 0);
992         break;
993     }
994 
995     return xfer * unit;
996 }
997 
998 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
999 {
1000     cmd->xfer = scsi_cdb_xfer(buf);
1001     switch (buf[0]) {
1002     case TEST_UNIT_READY:
1003     case REWIND:
1004     case START_STOP:
1005     case SET_CAPACITY:
1006     case WRITE_FILEMARKS:
1007     case WRITE_FILEMARKS_16:
1008     case SPACE:
1009     case RESERVE:
1010     case RELEASE:
1011     case ERASE:
1012     case ALLOW_MEDIUM_REMOVAL:
1013     case SEEK_10:
1014     case SYNCHRONIZE_CACHE:
1015     case SYNCHRONIZE_CACHE_16:
1016     case LOCATE_16:
1017     case LOCK_UNLOCK_CACHE:
1018     case SET_CD_SPEED:
1019     case SET_LIMITS:
1020     case WRITE_LONG_10:
1021     case UPDATE_BLOCK:
1022     case RESERVE_TRACK:
1023     case SET_READ_AHEAD:
1024     case PRE_FETCH:
1025     case PRE_FETCH_16:
1026     case ALLOW_OVERWRITE:
1027         cmd->xfer = 0;
1028         break;
1029     case VERIFY_10:
1030     case VERIFY_12:
1031     case VERIFY_16:
1032         if ((buf[1] & 2) == 0) {
1033             cmd->xfer = 0;
1034         } else if ((buf[1] & 4) != 0) {
1035             cmd->xfer = 1;
1036         }
1037         cmd->xfer *= dev->blocksize;
1038         break;
1039     case MODE_SENSE:
1040         break;
1041     case WRITE_SAME_10:
1042     case WRITE_SAME_16:
1043         cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
1044         break;
1045     case READ_CAPACITY_10:
1046         cmd->xfer = 8;
1047         break;
1048     case READ_BLOCK_LIMITS:
1049         cmd->xfer = 6;
1050         break;
1051     case SEND_VOLUME_TAG:
1052         /* GPCMD_SET_STREAMING from multimedia commands.  */
1053         if (dev->type == TYPE_ROM) {
1054             cmd->xfer = buf[10] | (buf[9] << 8);
1055         } else {
1056             cmd->xfer = buf[9] | (buf[8] << 8);
1057         }
1058         break;
1059     case WRITE_6:
1060         /* length 0 means 256 blocks */
1061         if (cmd->xfer == 0) {
1062             cmd->xfer = 256;
1063         }
1064         /* fall through */
1065     case WRITE_10:
1066     case WRITE_VERIFY_10:
1067     case WRITE_12:
1068     case WRITE_VERIFY_12:
1069     case WRITE_16:
1070     case WRITE_VERIFY_16:
1071         cmd->xfer *= dev->blocksize;
1072         break;
1073     case READ_6:
1074     case READ_REVERSE:
1075         /* length 0 means 256 blocks */
1076         if (cmd->xfer == 0) {
1077             cmd->xfer = 256;
1078         }
1079         /* fall through */
1080     case READ_10:
1081     case READ_12:
1082     case READ_16:
1083         cmd->xfer *= dev->blocksize;
1084         break;
1085     case FORMAT_UNIT:
1086         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1087          * for block devices are restricted to the header right now.  */
1088         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1089             cmd->xfer = 12;
1090         } else {
1091             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1092         }
1093         break;
1094     case INQUIRY:
1095     case RECEIVE_DIAGNOSTIC:
1096     case SEND_DIAGNOSTIC:
1097         cmd->xfer = buf[4] | (buf[3] << 8);
1098         break;
1099     case READ_CD:
1100     case READ_BUFFER:
1101     case WRITE_BUFFER:
1102     case SEND_CUE_SHEET:
1103         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1104         break;
1105     case PERSISTENT_RESERVE_OUT:
1106         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1107         break;
1108     case ERASE_12:
1109         if (dev->type == TYPE_ROM) {
1110             /* MMC command GET PERFORMANCE.  */
1111             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1112                                                     buf[10], buf[1] & 0x1f);
1113         }
1114         break;
1115     case MECHANISM_STATUS:
1116     case READ_DVD_STRUCTURE:
1117     case SEND_DVD_STRUCTURE:
1118     case MAINTENANCE_OUT:
1119     case MAINTENANCE_IN:
1120         if (dev->type == TYPE_ROM) {
1121             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1122             cmd->xfer = buf[9] | (buf[8] << 8);
1123         }
1124         break;
1125     case ATA_PASSTHROUGH_12:
1126         if (dev->type == TYPE_ROM) {
1127             /* BLANK command of MMC */
1128             cmd->xfer = 0;
1129         } else {
1130             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1131         }
1132         break;
1133     case ATA_PASSTHROUGH_16:
1134         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1135         break;
1136     }
1137     return 0;
1138 }
1139 
1140 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1141 {
1142     switch (buf[0]) {
1143     /* stream commands */
1144     case ERASE_12:
1145     case ERASE_16:
1146         cmd->xfer = 0;
1147         break;
1148     case READ_6:
1149     case READ_REVERSE:
1150     case RECOVER_BUFFERED_DATA:
1151     case WRITE_6:
1152         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1153         if (buf[1] & 0x01) { /* fixed */
1154             cmd->xfer *= dev->blocksize;
1155         }
1156         break;
1157     case READ_16:
1158     case READ_REVERSE_16:
1159     case VERIFY_16:
1160     case WRITE_16:
1161         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1162         if (buf[1] & 0x01) { /* fixed */
1163             cmd->xfer *= dev->blocksize;
1164         }
1165         break;
1166     case REWIND:
1167     case LOAD_UNLOAD:
1168         cmd->xfer = 0;
1169         break;
1170     case SPACE_16:
1171         cmd->xfer = buf[13] | (buf[12] << 8);
1172         break;
1173     case READ_POSITION:
1174         switch (buf[1] & 0x1f) /* operation code */ {
1175         case SHORT_FORM_BLOCK_ID:
1176         case SHORT_FORM_VENDOR_SPECIFIC:
1177             cmd->xfer = 20;
1178             break;
1179         case LONG_FORM:
1180             cmd->xfer = 32;
1181             break;
1182         case EXTENDED_FORM:
1183             cmd->xfer = buf[8] | (buf[7] << 8);
1184             break;
1185         default:
1186             return -1;
1187         }
1188 
1189         break;
1190     case FORMAT_UNIT:
1191         cmd->xfer = buf[4] | (buf[3] << 8);
1192         break;
1193     /* generic commands */
1194     default:
1195         return scsi_req_xfer(cmd, dev, buf);
1196     }
1197     return 0;
1198 }
1199 
1200 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1201 {
1202     switch (buf[0]) {
1203     /* medium changer commands */
1204     case EXCHANGE_MEDIUM:
1205     case INITIALIZE_ELEMENT_STATUS:
1206     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1207     case MOVE_MEDIUM:
1208     case POSITION_TO_ELEMENT:
1209         cmd->xfer = 0;
1210         break;
1211     case READ_ELEMENT_STATUS:
1212         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1213         break;
1214 
1215     /* generic commands */
1216     default:
1217         return scsi_req_xfer(cmd, dev, buf);
1218     }
1219     return 0;
1220 }
1221 
1222 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1223 {
1224     switch (buf[0]) {
1225     /* Scanner commands */
1226     case OBJECT_POSITION:
1227         cmd->xfer = 0;
1228         break;
1229     case SCAN:
1230         cmd->xfer = buf[4];
1231         break;
1232     case READ_10:
1233     case SEND:
1234     case GET_WINDOW:
1235     case SET_WINDOW:
1236         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1237         break;
1238     default:
1239         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1240         return scsi_req_xfer(cmd, dev, buf);
1241     }
1242 
1243     return 0;
1244 }
1245 
1246 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1247 {
1248     if (!cmd->xfer) {
1249         cmd->mode = SCSI_XFER_NONE;
1250         return;
1251     }
1252     switch (cmd->buf[0]) {
1253     case WRITE_6:
1254     case WRITE_10:
1255     case WRITE_VERIFY_10:
1256     case WRITE_12:
1257     case WRITE_VERIFY_12:
1258     case WRITE_16:
1259     case WRITE_VERIFY_16:
1260     case VERIFY_10:
1261     case VERIFY_12:
1262     case VERIFY_16:
1263     case COPY:
1264     case COPY_VERIFY:
1265     case COMPARE:
1266     case CHANGE_DEFINITION:
1267     case LOG_SELECT:
1268     case MODE_SELECT:
1269     case MODE_SELECT_10:
1270     case SEND_DIAGNOSTIC:
1271     case WRITE_BUFFER:
1272     case FORMAT_UNIT:
1273     case REASSIGN_BLOCKS:
1274     case SEARCH_EQUAL:
1275     case SEARCH_HIGH:
1276     case SEARCH_LOW:
1277     case UPDATE_BLOCK:
1278     case WRITE_LONG_10:
1279     case WRITE_SAME_10:
1280     case WRITE_SAME_16:
1281     case UNMAP:
1282     case SEARCH_HIGH_12:
1283     case SEARCH_EQUAL_12:
1284     case SEARCH_LOW_12:
1285     case MEDIUM_SCAN:
1286     case SEND_VOLUME_TAG:
1287     case SEND_CUE_SHEET:
1288     case SEND_DVD_STRUCTURE:
1289     case PERSISTENT_RESERVE_OUT:
1290     case MAINTENANCE_OUT:
1291     case SET_WINDOW:
1292     case SCAN:
1293         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1294          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1295          */
1296         cmd->mode = SCSI_XFER_TO_DEV;
1297         break;
1298     case ATA_PASSTHROUGH_12:
1299     case ATA_PASSTHROUGH_16:
1300         /* T_DIR */
1301         cmd->mode = (cmd->buf[2] & 0x8) ?
1302                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1303         break;
1304     default:
1305         cmd->mode = SCSI_XFER_FROM_DEV;
1306         break;
1307     }
1308 }
1309 
1310 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf)
1311 {
1312     int rc;
1313     int len;
1314 
1315     cmd->lba = -1;
1316     len = scsi_cdb_length(buf);
1317     if (len < 0) {
1318         return -1;
1319     }
1320 
1321     cmd->len = len;
1322     switch (dev->type) {
1323     case TYPE_TAPE:
1324         rc = scsi_req_stream_xfer(cmd, dev, buf);
1325         break;
1326     case TYPE_MEDIUM_CHANGER:
1327         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1328         break;
1329     case TYPE_SCANNER:
1330         rc = scsi_req_scanner_length(cmd, dev, buf);
1331         break;
1332     default:
1333         rc = scsi_req_xfer(cmd, dev, buf);
1334         break;
1335     }
1336 
1337     if (rc != 0)
1338         return rc;
1339 
1340     memcpy(cmd->buf, buf, cmd->len);
1341     scsi_cmd_xfer_mode(cmd);
1342     cmd->lba = scsi_cmd_lba(cmd);
1343     return 0;
1344 }
1345 
1346 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1347 {
1348     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1349 
1350     scsi_device_set_ua(dev, sense);
1351     if (bus->info->change) {
1352         bus->info->change(bus, dev, sense);
1353     }
1354 }
1355 
1356 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1357 {
1358     assert(req->refcount > 0);
1359     req->refcount++;
1360     return req;
1361 }
1362 
1363 void scsi_req_unref(SCSIRequest *req)
1364 {
1365     assert(req->refcount > 0);
1366     if (--req->refcount == 0) {
1367         BusState *qbus = req->dev->qdev.parent_bus;
1368         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1369 
1370         if (bus->info->free_request && req->hba_private) {
1371             bus->info->free_request(bus, req->hba_private);
1372         }
1373         if (req->ops->free_req) {
1374             req->ops->free_req(req);
1375         }
1376         object_unref(OBJECT(req->dev));
1377         object_unref(OBJECT(qbus->parent));
1378         g_free(req);
1379     }
1380 }
1381 
1382 /* Tell the device that we finished processing this chunk of I/O.  It
1383    will start the next chunk or complete the command.  */
1384 void scsi_req_continue(SCSIRequest *req)
1385 {
1386     if (req->io_canceled) {
1387         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1388         return;
1389     }
1390     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1391     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1392         req->ops->write_data(req);
1393     } else {
1394         req->ops->read_data(req);
1395     }
1396 }
1397 
1398 /* Called by the devices when data is ready for the HBA.  The HBA should
1399    start a DMA operation to read or fill the device's data buffer.
1400    Once it completes, calling scsi_req_continue will restart I/O.  */
1401 void scsi_req_data(SCSIRequest *req, int len)
1402 {
1403     uint8_t *buf;
1404     if (req->io_canceled) {
1405         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1406         return;
1407     }
1408     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1409     assert(req->cmd.mode != SCSI_XFER_NONE);
1410     if (!req->sg) {
1411         req->resid -= len;
1412         req->bus->info->transfer_data(req, len);
1413         return;
1414     }
1415 
1416     /* If the device calls scsi_req_data and the HBA specified a
1417      * scatter/gather list, the transfer has to happen in a single
1418      * step.  */
1419     assert(!req->dma_started);
1420     req->dma_started = true;
1421 
1422     buf = scsi_req_get_buf(req);
1423     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1424         req->resid = dma_buf_read(buf, len, req->sg, MEMTXATTRS_UNSPECIFIED);
1425     } else {
1426         req->resid = dma_buf_write(buf, len, req->sg, MEMTXATTRS_UNSPECIFIED);
1427     }
1428     scsi_req_continue(req);
1429 }
1430 
1431 void scsi_req_print(SCSIRequest *req)
1432 {
1433     FILE *fp = stderr;
1434     int i;
1435 
1436     fprintf(fp, "[%s id=%d] %s",
1437             req->dev->qdev.parent_bus->name,
1438             req->dev->id,
1439             scsi_command_name(req->cmd.buf[0]));
1440     for (i = 1; i < req->cmd.len; i++) {
1441         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1442     }
1443     switch (req->cmd.mode) {
1444     case SCSI_XFER_NONE:
1445         fprintf(fp, " - none\n");
1446         break;
1447     case SCSI_XFER_FROM_DEV:
1448         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1449         break;
1450     case SCSI_XFER_TO_DEV:
1451         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1452         break;
1453     default:
1454         fprintf(fp, " - Oops\n");
1455         break;
1456     }
1457 }
1458 
1459 void scsi_req_complete_failed(SCSIRequest *req, int host_status)
1460 {
1461     SCSISense sense;
1462     int status;
1463 
1464     assert(req->status == -1 && req->host_status == -1);
1465     assert(req->ops != &reqops_unit_attention);
1466 
1467     if (!req->bus->info->fail) {
1468         status = scsi_sense_from_host_status(req->host_status, &sense);
1469         if (status == CHECK_CONDITION) {
1470             scsi_req_build_sense(req, sense);
1471         }
1472         scsi_req_complete(req, status);
1473         return;
1474     }
1475 
1476     req->host_status = host_status;
1477     scsi_req_ref(req);
1478     scsi_req_dequeue(req);
1479     req->bus->info->fail(req);
1480 
1481     /* Cancelled requests might end up being completed instead of cancelled */
1482     notifier_list_notify(&req->cancel_notifiers, req);
1483     scsi_req_unref(req);
1484 }
1485 
1486 void scsi_req_complete(SCSIRequest *req, int status)
1487 {
1488     assert(req->status == -1 && req->host_status == -1);
1489     req->status = status;
1490     req->host_status = SCSI_HOST_OK;
1491 
1492     assert(req->sense_len <= sizeof(req->sense));
1493     if (status == GOOD) {
1494         req->sense_len = 0;
1495     }
1496 
1497     if (req->sense_len) {
1498         memcpy(req->dev->sense, req->sense, req->sense_len);
1499         req->dev->sense_len = req->sense_len;
1500         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1501     } else {
1502         req->dev->sense_len = 0;
1503         req->dev->sense_is_ua = false;
1504     }
1505 
1506     /*
1507      * Unit attention state is now stored in the device's sense buffer
1508      * if the HBA didn't do autosense.  Clear the pending unit attention
1509      * flags.
1510      */
1511     scsi_clear_unit_attention(req);
1512 
1513     scsi_req_ref(req);
1514     scsi_req_dequeue(req);
1515     req->bus->info->complete(req, req->resid);
1516 
1517     /* Cancelled requests might end up being completed instead of cancelled */
1518     notifier_list_notify(&req->cancel_notifiers, req);
1519     scsi_req_unref(req);
1520 }
1521 
1522 /* Called by the devices when the request is canceled. */
1523 void scsi_req_cancel_complete(SCSIRequest *req)
1524 {
1525     assert(req->io_canceled);
1526     if (req->bus->info->cancel) {
1527         req->bus->info->cancel(req);
1528     }
1529     notifier_list_notify(&req->cancel_notifiers, req);
1530     scsi_req_unref(req);
1531 }
1532 
1533 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1534  * notifier list, the bus will be notified the requests cancellation is
1535  * completed.
1536  * */
1537 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1538 {
1539     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1540     if (notifier) {
1541         notifier_list_add(&req->cancel_notifiers, notifier);
1542     }
1543     if (req->io_canceled) {
1544         /* A blk_aio_cancel_async is pending; when it finishes,
1545          * scsi_req_cancel_complete will be called and will
1546          * call the notifier we just added.  Just wait for that.
1547          */
1548         assert(req->aiocb);
1549         return;
1550     }
1551     /* Dropped in scsi_req_cancel_complete.  */
1552     scsi_req_ref(req);
1553     scsi_req_dequeue(req);
1554     req->io_canceled = true;
1555     if (req->aiocb) {
1556         blk_aio_cancel_async(req->aiocb);
1557     } else {
1558         scsi_req_cancel_complete(req);
1559     }
1560 }
1561 
1562 void scsi_req_cancel(SCSIRequest *req)
1563 {
1564     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1565     if (!req->enqueued) {
1566         return;
1567     }
1568     assert(!req->io_canceled);
1569     /* Dropped in scsi_req_cancel_complete.  */
1570     scsi_req_ref(req);
1571     scsi_req_dequeue(req);
1572     req->io_canceled = true;
1573     if (req->aiocb) {
1574         blk_aio_cancel(req->aiocb);
1575     } else {
1576         scsi_req_cancel_complete(req);
1577     }
1578 }
1579 
1580 static int scsi_ua_precedence(SCSISense sense)
1581 {
1582     if (sense.key != UNIT_ATTENTION) {
1583         return INT_MAX;
1584     }
1585     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1586         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1587         return 1;
1588     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1589         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1590         return 2;
1591     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1592         /* These two go with "all others". */
1593         ;
1594     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1595         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1596          * POWER ON OCCURRED = 1
1597          * SCSI BUS RESET OCCURRED = 2
1598          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1599          * I_T NEXUS LOSS OCCURRED = 7
1600          */
1601         return sense.ascq;
1602     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1603         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1604         return 8;
1605     }
1606     return (sense.asc << 8) | sense.ascq;
1607 }
1608 
1609 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1610 {
1611     int prec1, prec2;
1612     if (sense.key != UNIT_ATTENTION) {
1613         return;
1614     }
1615     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1616                              sense.asc, sense.ascq);
1617 
1618     /*
1619      * Override a pre-existing unit attention condition, except for a more
1620      * important reset condition.
1621     */
1622     prec1 = scsi_ua_precedence(sdev->unit_attention);
1623     prec2 = scsi_ua_precedence(sense);
1624     if (prec2 < prec1) {
1625         sdev->unit_attention = sense;
1626     }
1627 }
1628 
1629 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1630 {
1631     SCSIRequest *req;
1632 
1633     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1634     while (!QTAILQ_EMPTY(&sdev->requests)) {
1635         req = QTAILQ_FIRST(&sdev->requests);
1636         scsi_req_cancel_async(req, NULL);
1637     }
1638     blk_drain(sdev->conf.blk);
1639     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1640     scsi_device_set_ua(sdev, sense);
1641 }
1642 
1643 static char *scsibus_get_dev_path(DeviceState *dev)
1644 {
1645     SCSIDevice *d = SCSI_DEVICE(dev);
1646     DeviceState *hba = dev->parent_bus->parent;
1647     char *id;
1648     char *path;
1649 
1650     id = qdev_get_dev_path(hba);
1651     if (id) {
1652         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1653     } else {
1654         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1655     }
1656     g_free(id);
1657     return path;
1658 }
1659 
1660 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1661 {
1662     SCSIDevice *d = SCSI_DEVICE(dev);
1663     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1664                            qdev_fw_name(dev), d->id, d->lun);
1665 }
1666 
1667 /* SCSI request list.  For simplicity, pv points to the whole device */
1668 
1669 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1670                              const VMStateField *field, JSONWriter *vmdesc)
1671 {
1672     SCSIDevice *s = pv;
1673     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1674     SCSIRequest *req;
1675 
1676     QTAILQ_FOREACH(req, &s->requests, next) {
1677         assert(!req->io_canceled);
1678         assert(req->status == -1 && req->host_status == -1);
1679         assert(req->enqueued);
1680 
1681         qemu_put_sbyte(f, req->retry ? 1 : 2);
1682         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1683         qemu_put_be32s(f, &req->tag);
1684         qemu_put_be32s(f, &req->lun);
1685         if (bus->info->save_request) {
1686             bus->info->save_request(f, req);
1687         }
1688         if (req->ops->save_request) {
1689             req->ops->save_request(f, req);
1690         }
1691     }
1692     qemu_put_sbyte(f, 0);
1693 
1694     return 0;
1695 }
1696 
1697 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1698                              const VMStateField *field)
1699 {
1700     SCSIDevice *s = pv;
1701     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1702     int8_t sbyte;
1703 
1704     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1705         uint8_t buf[SCSI_CMD_BUF_SIZE];
1706         uint32_t tag;
1707         uint32_t lun;
1708         SCSIRequest *req;
1709 
1710         qemu_get_buffer(f, buf, sizeof(buf));
1711         qemu_get_be32s(f, &tag);
1712         qemu_get_be32s(f, &lun);
1713         req = scsi_req_new(s, tag, lun, buf, NULL);
1714         req->retry = (sbyte == 1);
1715         if (bus->info->load_request) {
1716             req->hba_private = bus->info->load_request(f, req);
1717         }
1718         if (req->ops->load_request) {
1719             req->ops->load_request(f, req);
1720         }
1721 
1722         /* Just restart it later.  */
1723         scsi_req_enqueue_internal(req);
1724 
1725         /* At this point, the request will be kept alive by the reference
1726          * added by scsi_req_enqueue_internal, so we can release our reference.
1727          * The HBA of course will add its own reference in the load_request
1728          * callback if it needs to hold on the SCSIRequest.
1729          */
1730         scsi_req_unref(req);
1731     }
1732 
1733     return 0;
1734 }
1735 
1736 static const VMStateInfo vmstate_info_scsi_requests = {
1737     .name = "scsi-requests",
1738     .get  = get_scsi_requests,
1739     .put  = put_scsi_requests,
1740 };
1741 
1742 static bool scsi_sense_state_needed(void *opaque)
1743 {
1744     SCSIDevice *s = opaque;
1745 
1746     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1747 }
1748 
1749 static const VMStateDescription vmstate_scsi_sense_state = {
1750     .name = "SCSIDevice/sense",
1751     .version_id = 1,
1752     .minimum_version_id = 1,
1753     .needed = scsi_sense_state_needed,
1754     .fields = (VMStateField[]) {
1755         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1756                                 SCSI_SENSE_BUF_SIZE_OLD,
1757                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1758         VMSTATE_END_OF_LIST()
1759     }
1760 };
1761 
1762 const VMStateDescription vmstate_scsi_device = {
1763     .name = "SCSIDevice",
1764     .version_id = 1,
1765     .minimum_version_id = 1,
1766     .fields = (VMStateField[]) {
1767         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1768         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1769         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1770         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1771         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1772         VMSTATE_UINT32(sense_len, SCSIDevice),
1773         {
1774             .name         = "requests",
1775             .version_id   = 0,
1776             .field_exists = NULL,
1777             .size         = 0,   /* ouch */
1778             .info         = &vmstate_info_scsi_requests,
1779             .flags        = VMS_SINGLE,
1780             .offset       = 0,
1781         },
1782         VMSTATE_END_OF_LIST()
1783     },
1784     .subsections = (const VMStateDescription*[]) {
1785         &vmstate_scsi_sense_state,
1786         NULL
1787     }
1788 };
1789 
1790 static Property scsi_props[] = {
1791     DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
1792     DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
1793     DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
1794     DEFINE_PROP_END_OF_LIST(),
1795 };
1796 
1797 static void scsi_device_class_init(ObjectClass *klass, void *data)
1798 {
1799     DeviceClass *k = DEVICE_CLASS(klass);
1800     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1801     k->bus_type  = TYPE_SCSI_BUS;
1802     k->realize   = scsi_qdev_realize;
1803     k->unrealize = scsi_qdev_unrealize;
1804     device_class_set_props(k, scsi_props);
1805 }
1806 
1807 static void scsi_dev_instance_init(Object *obj)
1808 {
1809     DeviceState *dev = DEVICE(obj);
1810     SCSIDevice *s = SCSI_DEVICE(dev);
1811 
1812     device_add_bootindex_property(obj, &s->conf.bootindex,
1813                                   "bootindex", NULL,
1814                                   &s->qdev);
1815 }
1816 
1817 static const TypeInfo scsi_device_type_info = {
1818     .name = TYPE_SCSI_DEVICE,
1819     .parent = TYPE_DEVICE,
1820     .instance_size = sizeof(SCSIDevice),
1821     .abstract = true,
1822     .class_size = sizeof(SCSIDeviceClass),
1823     .class_init = scsi_device_class_init,
1824     .instance_init = scsi_dev_instance_init,
1825 };
1826 
1827 static void scsi_bus_class_init(ObjectClass *klass, void *data)
1828 {
1829     BusClass *k = BUS_CLASS(klass);
1830     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1831 
1832     k->get_dev_path = scsibus_get_dev_path;
1833     k->get_fw_dev_path = scsibus_get_fw_dev_path;
1834     k->check_address = scsi_bus_check_address;
1835     hc->unplug = qdev_simple_device_unplug_cb;
1836 }
1837 
1838 static const TypeInfo scsi_bus_info = {
1839     .name = TYPE_SCSI_BUS,
1840     .parent = TYPE_BUS,
1841     .instance_size = sizeof(SCSIBus),
1842     .class_init = scsi_bus_class_init,
1843     .interfaces = (InterfaceInfo[]) {
1844         { TYPE_HOTPLUG_HANDLER },
1845         { }
1846     }
1847 };
1848 
1849 static void scsi_register_types(void)
1850 {
1851     type_register_static(&scsi_bus_info);
1852     type_register_static(&scsi_device_type_info);
1853 }
1854 
1855 type_init(scsi_register_types)
1856