xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision 9f2d175d)
1 #include "qemu/osdep.h"
2 #include "hw/hw.h"
3 #include "qapi/error.h"
4 #include "qemu/error-report.h"
5 #include "qemu/option.h"
6 #include "hw/scsi/scsi.h"
7 #include "scsi/constants.h"
8 #include "hw/qdev.h"
9 #include "sysemu/block-backend.h"
10 #include "sysemu/blockdev.h"
11 #include "trace.h"
12 #include "sysemu/dma.h"
13 #include "qemu/cutils.h"
14 
15 static char *scsibus_get_dev_path(DeviceState *dev);
16 static char *scsibus_get_fw_dev_path(DeviceState *dev);
17 static void scsi_req_dequeue(SCSIRequest *req);
18 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len);
19 static void scsi_target_free_buf(SCSIRequest *req);
20 
21 static Property scsi_props[] = {
22     DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
23     DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
24     DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
25     DEFINE_PROP_END_OF_LIST(),
26 };
27 
28 static void scsi_bus_class_init(ObjectClass *klass, void *data)
29 {
30     BusClass *k = BUS_CLASS(klass);
31     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
32 
33     k->get_dev_path = scsibus_get_dev_path;
34     k->get_fw_dev_path = scsibus_get_fw_dev_path;
35     hc->unplug = qdev_simple_device_unplug_cb;
36 }
37 
38 static const TypeInfo scsi_bus_info = {
39     .name = TYPE_SCSI_BUS,
40     .parent = TYPE_BUS,
41     .instance_size = sizeof(SCSIBus),
42     .class_init = scsi_bus_class_init,
43     .interfaces = (InterfaceInfo[]) {
44         { TYPE_HOTPLUG_HANDLER },
45         { }
46     }
47 };
48 static int next_scsi_bus;
49 
50 static void scsi_device_realize(SCSIDevice *s, Error **errp)
51 {
52     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
53     if (sc->realize) {
54         sc->realize(s, errp);
55     }
56 }
57 
58 int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
59                        void *hba_private)
60 {
61     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
62     int rc;
63 
64     assert(cmd->len == 0);
65     rc = scsi_req_parse_cdb(dev, cmd, buf);
66     if (bus->info->parse_cdb) {
67         rc = bus->info->parse_cdb(dev, cmd, buf, hba_private);
68     }
69     return rc;
70 }
71 
72 static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
73                                           uint8_t *buf, void *hba_private)
74 {
75     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
76     if (sc->alloc_req) {
77         return sc->alloc_req(s, tag, lun, buf, hba_private);
78     }
79 
80     return NULL;
81 }
82 
83 void scsi_device_unit_attention_reported(SCSIDevice *s)
84 {
85     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
86     if (sc->unit_attention_reported) {
87         sc->unit_attention_reported(s);
88     }
89 }
90 
91 /* Create a scsi bus, and attach devices to it.  */
92 void scsi_bus_new(SCSIBus *bus, size_t bus_size, DeviceState *host,
93                   const SCSIBusInfo *info, const char *bus_name)
94 {
95     qbus_create_inplace(bus, bus_size, TYPE_SCSI_BUS, host, bus_name);
96     bus->busnr = next_scsi_bus++;
97     bus->info = info;
98     qbus_set_bus_hotplug_handler(BUS(bus), &error_abort);
99 }
100 
101 static void scsi_dma_restart_bh(void *opaque)
102 {
103     SCSIDevice *s = opaque;
104     SCSIRequest *req, *next;
105 
106     qemu_bh_delete(s->bh);
107     s->bh = NULL;
108 
109     aio_context_acquire(blk_get_aio_context(s->conf.blk));
110     QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
111         scsi_req_ref(req);
112         if (req->retry) {
113             req->retry = false;
114             switch (req->cmd.mode) {
115             case SCSI_XFER_FROM_DEV:
116             case SCSI_XFER_TO_DEV:
117                 scsi_req_continue(req);
118                 break;
119             case SCSI_XFER_NONE:
120                 scsi_req_dequeue(req);
121                 scsi_req_enqueue(req);
122                 break;
123             }
124         }
125         scsi_req_unref(req);
126     }
127     aio_context_release(blk_get_aio_context(s->conf.blk));
128 }
129 
130 void scsi_req_retry(SCSIRequest *req)
131 {
132     /* No need to save a reference, because scsi_dma_restart_bh just
133      * looks at the request list.  */
134     req->retry = true;
135 }
136 
137 static void scsi_dma_restart_cb(void *opaque, int running, RunState state)
138 {
139     SCSIDevice *s = opaque;
140 
141     if (!running) {
142         return;
143     }
144     if (!s->bh) {
145         AioContext *ctx = blk_get_aio_context(s->conf.blk);
146         s->bh = aio_bh_new(ctx, scsi_dma_restart_bh, s);
147         qemu_bh_schedule(s->bh);
148     }
149 }
150 
151 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
152 {
153     SCSIDevice *dev = SCSI_DEVICE(qdev);
154     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
155     SCSIDevice *d;
156     Error *local_err = NULL;
157 
158     if (dev->channel > bus->info->max_channel) {
159         error_setg(errp, "bad scsi channel id: %d", dev->channel);
160         return;
161     }
162     if (dev->id != -1 && dev->id > bus->info->max_target) {
163         error_setg(errp, "bad scsi device id: %d", dev->id);
164         return;
165     }
166     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
167         error_setg(errp, "bad scsi device lun: %d", dev->lun);
168         return;
169     }
170 
171     if (dev->id == -1) {
172         int id = -1;
173         if (dev->lun == -1) {
174             dev->lun = 0;
175         }
176         do {
177             d = scsi_device_find(bus, dev->channel, ++id, dev->lun);
178         } while (d && d->lun == dev->lun && id < bus->info->max_target);
179         if (d && d->lun == dev->lun) {
180             error_setg(errp, "no free target");
181             return;
182         }
183         dev->id = id;
184     } else if (dev->lun == -1) {
185         int lun = -1;
186         do {
187             d = scsi_device_find(bus, dev->channel, dev->id, ++lun);
188         } while (d && d->lun == lun && lun < bus->info->max_lun);
189         if (d && d->lun == lun) {
190             error_setg(errp, "no free lun");
191             return;
192         }
193         dev->lun = lun;
194     } else {
195         d = scsi_device_find(bus, dev->channel, dev->id, dev->lun);
196         assert(d);
197         if (d->lun == dev->lun && dev != d) {
198             error_setg(errp, "lun already used by '%s'", d->qdev.id);
199             return;
200         }
201     }
202 
203     QTAILQ_INIT(&dev->requests);
204     scsi_device_realize(dev, &local_err);
205     if (local_err) {
206         error_propagate(errp, local_err);
207         return;
208     }
209     dev->vmsentry = qemu_add_vm_change_state_handler(scsi_dma_restart_cb,
210                                                      dev);
211 }
212 
213 static void scsi_qdev_unrealize(DeviceState *qdev, Error **errp)
214 {
215     SCSIDevice *dev = SCSI_DEVICE(qdev);
216 
217     if (dev->vmsentry) {
218         qemu_del_vm_change_state_handler(dev->vmsentry);
219     }
220 
221     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
222     blockdev_mark_auto_del(dev->conf.blk);
223 }
224 
225 /* handle legacy '-drive if=scsi,...' cmd line args */
226 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
227                                       int unit, bool removable, int bootindex,
228                                       bool share_rw,
229                                       const char *serial, Error **errp)
230 {
231     const char *driver;
232     char *name;
233     DeviceState *dev;
234     Error *err = NULL;
235 
236     driver = blk_is_sg(blk) ? "scsi-generic" : "scsi-disk";
237     dev = qdev_create(&bus->qbus, driver);
238     name = g_strdup_printf("legacy[%d]", unit);
239     object_property_add_child(OBJECT(bus), name, OBJECT(dev), NULL);
240     g_free(name);
241 
242     qdev_prop_set_uint32(dev, "scsi-id", unit);
243     if (bootindex >= 0) {
244         object_property_set_int(OBJECT(dev), bootindex, "bootindex",
245                                 &error_abort);
246     }
247     if (object_property_find(OBJECT(dev), "removable", NULL)) {
248         qdev_prop_set_bit(dev, "removable", removable);
249     }
250     if (serial && object_property_find(OBJECT(dev), "serial", NULL)) {
251         qdev_prop_set_string(dev, "serial", serial);
252     }
253     qdev_prop_set_drive(dev, "drive", blk, &err);
254     if (err) {
255         error_propagate(errp, err);
256         object_unparent(OBJECT(dev));
257         return NULL;
258     }
259     object_property_set_bool(OBJECT(dev), share_rw, "share-rw", &err);
260     if (err != NULL) {
261         error_propagate(errp, err);
262         object_unparent(OBJECT(dev));
263         return NULL;
264     }
265     object_property_set_bool(OBJECT(dev), true, "realized", &err);
266     if (err != NULL) {
267         error_propagate(errp, err);
268         object_unparent(OBJECT(dev));
269         return NULL;
270     }
271     return SCSI_DEVICE(dev);
272 }
273 
274 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
275 {
276     Location loc;
277     DriveInfo *dinfo;
278     int unit;
279 
280     loc_push_none(&loc);
281     for (unit = 0; unit <= bus->info->max_target; unit++) {
282         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
283         if (dinfo == NULL) {
284             continue;
285         }
286         qemu_opts_loc_restore(dinfo->opts);
287         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
288                                   unit, false, -1, false, NULL, &error_fatal);
289     }
290     loc_pop(&loc);
291 }
292 
293 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
294 {
295     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
296     scsi_req_complete(req, CHECK_CONDITION);
297     return 0;
298 }
299 
300 static const struct SCSIReqOps reqops_invalid_field = {
301     .size         = sizeof(SCSIRequest),
302     .send_command = scsi_invalid_field
303 };
304 
305 /* SCSIReqOps implementation for invalid commands.  */
306 
307 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
308 {
309     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
310     scsi_req_complete(req, CHECK_CONDITION);
311     return 0;
312 }
313 
314 static const struct SCSIReqOps reqops_invalid_opcode = {
315     .size         = sizeof(SCSIRequest),
316     .send_command = scsi_invalid_command
317 };
318 
319 /* SCSIReqOps implementation for unit attention conditions.  */
320 
321 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
322 {
323     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
324         scsi_req_build_sense(req, req->dev->unit_attention);
325     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
326         scsi_req_build_sense(req, req->bus->unit_attention);
327     }
328     scsi_req_complete(req, CHECK_CONDITION);
329     return 0;
330 }
331 
332 static const struct SCSIReqOps reqops_unit_attention = {
333     .size         = sizeof(SCSIRequest),
334     .send_command = scsi_unit_attention
335 };
336 
337 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
338    an invalid LUN.  */
339 
340 typedef struct SCSITargetReq SCSITargetReq;
341 
342 struct SCSITargetReq {
343     SCSIRequest req;
344     int len;
345     uint8_t *buf;
346     int buf_len;
347 };
348 
349 static void store_lun(uint8_t *outbuf, int lun)
350 {
351     if (lun < 256) {
352         outbuf[1] = lun;
353         return;
354     }
355     outbuf[1] = (lun & 255);
356     outbuf[0] = (lun >> 8) | 0x40;
357 }
358 
359 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
360 {
361     BusChild *kid;
362     int i, len, n;
363     int channel, id;
364     bool found_lun0;
365 
366     if (r->req.cmd.xfer < 16) {
367         return false;
368     }
369     if (r->req.cmd.buf[2] > 2) {
370         return false;
371     }
372     channel = r->req.dev->channel;
373     id = r->req.dev->id;
374     found_lun0 = false;
375     n = 0;
376     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
377         DeviceState *qdev = kid->child;
378         SCSIDevice *dev = SCSI_DEVICE(qdev);
379 
380         if (dev->channel == channel && dev->id == id) {
381             if (dev->lun == 0) {
382                 found_lun0 = true;
383             }
384             n += 8;
385         }
386     }
387     if (!found_lun0) {
388         n += 8;
389     }
390 
391     scsi_target_alloc_buf(&r->req, n + 8);
392 
393     len = MIN(n + 8, r->req.cmd.xfer & ~7);
394     memset(r->buf, 0, len);
395     stl_be_p(&r->buf[0], n);
396     i = found_lun0 ? 8 : 16;
397     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
398         DeviceState *qdev = kid->child;
399         SCSIDevice *dev = SCSI_DEVICE(qdev);
400 
401         if (dev->channel == channel && dev->id == id) {
402             store_lun(&r->buf[i], dev->lun);
403             i += 8;
404         }
405     }
406     assert(i == n + 8);
407     r->len = len;
408     return true;
409 }
410 
411 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
412 {
413     assert(r->req.dev->lun != r->req.lun);
414 
415     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
416 
417     if (r->req.cmd.buf[1] & 0x2) {
418         /* Command support data - optional, not implemented */
419         return false;
420     }
421 
422     if (r->req.cmd.buf[1] & 0x1) {
423         /* Vital product data */
424         uint8_t page_code = r->req.cmd.buf[2];
425         r->buf[r->len++] = page_code ; /* this page */
426         r->buf[r->len++] = 0x00;
427 
428         switch (page_code) {
429         case 0x00: /* Supported page codes, mandatory */
430         {
431             int pages;
432             pages = r->len++;
433             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
434             r->buf[pages] = r->len - pages - 1; /* number of pages */
435             break;
436         }
437         default:
438             return false;
439         }
440         /* done with EVPD */
441         assert(r->len < r->buf_len);
442         r->len = MIN(r->req.cmd.xfer, r->len);
443         return true;
444     }
445 
446     /* Standard INQUIRY data */
447     if (r->req.cmd.buf[2] != 0) {
448         return false;
449     }
450 
451     /* PAGE CODE == 0 */
452     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
453     memset(r->buf, 0, r->len);
454     if (r->req.lun != 0) {
455         r->buf[0] = TYPE_NO_LUN;
456     } else {
457         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
458         r->buf[2] = 5; /* Version */
459         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
460         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
461         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
462         memcpy(&r->buf[8], "QEMU    ", 8);
463         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
464         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
465     }
466     return true;
467 }
468 
469 static size_t scsi_sense_len(SCSIRequest *req)
470 {
471     if (req->dev->type == TYPE_SCANNER)
472         return SCSI_SENSE_LEN_SCANNER;
473     else
474         return SCSI_SENSE_LEN;
475 }
476 
477 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
478 {
479     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
480     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
481 
482     if (req->lun != 0 &&
483         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
484         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
485         scsi_req_complete(req, CHECK_CONDITION);
486         return 0;
487     }
488     switch (buf[0]) {
489     case REPORT_LUNS:
490         if (!scsi_target_emulate_report_luns(r)) {
491             goto illegal_request;
492         }
493         break;
494     case INQUIRY:
495         if (!scsi_target_emulate_inquiry(r)) {
496             goto illegal_request;
497         }
498         break;
499     case REQUEST_SENSE:
500         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
501         if (req->lun != 0) {
502             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
503 
504             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
505                                           sense, fixed_sense);
506         } else {
507             r->len = scsi_device_get_sense(r->req.dev, r->buf,
508                                            MIN(req->cmd.xfer, r->buf_len),
509                                            fixed_sense);
510         }
511         if (r->req.dev->sense_is_ua) {
512             scsi_device_unit_attention_reported(req->dev);
513             r->req.dev->sense_len = 0;
514             r->req.dev->sense_is_ua = false;
515         }
516         break;
517     case TEST_UNIT_READY:
518         break;
519     default:
520         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
521         scsi_req_complete(req, CHECK_CONDITION);
522         return 0;
523     illegal_request:
524         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
525         scsi_req_complete(req, CHECK_CONDITION);
526         return 0;
527     }
528 
529     if (!r->len) {
530         scsi_req_complete(req, GOOD);
531     }
532     return r->len;
533 }
534 
535 static void scsi_target_read_data(SCSIRequest *req)
536 {
537     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
538     uint32_t n;
539 
540     n = r->len;
541     if (n > 0) {
542         r->len = 0;
543         scsi_req_data(&r->req, n);
544     } else {
545         scsi_req_complete(&r->req, GOOD);
546     }
547 }
548 
549 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
550 {
551     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
552 
553     return r->buf;
554 }
555 
556 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
557 {
558     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
559 
560     r->buf = g_malloc(len);
561     r->buf_len = len;
562 
563     return r->buf;
564 }
565 
566 static void scsi_target_free_buf(SCSIRequest *req)
567 {
568     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
569 
570     g_free(r->buf);
571 }
572 
573 static const struct SCSIReqOps reqops_target_command = {
574     .size         = sizeof(SCSITargetReq),
575     .send_command = scsi_target_send_command,
576     .read_data    = scsi_target_read_data,
577     .get_buf      = scsi_target_get_buf,
578     .free_req     = scsi_target_free_buf,
579 };
580 
581 
582 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
583                             uint32_t tag, uint32_t lun, void *hba_private)
584 {
585     SCSIRequest *req;
586     SCSIBus *bus = scsi_bus_from_device(d);
587     BusState *qbus = BUS(bus);
588     const int memset_off = offsetof(SCSIRequest, sense)
589                            + sizeof(req->sense);
590 
591     req = g_malloc(reqops->size);
592     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
593     req->refcount = 1;
594     req->bus = bus;
595     req->dev = d;
596     req->tag = tag;
597     req->lun = lun;
598     req->hba_private = hba_private;
599     req->status = -1;
600     req->ops = reqops;
601     object_ref(OBJECT(d));
602     object_ref(OBJECT(qbus->parent));
603     notifier_list_init(&req->cancel_notifiers);
604     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
605     return req;
606 }
607 
608 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
609                           uint8_t *buf, void *hba_private)
610 {
611     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
612     const SCSIReqOps *ops;
613     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
614     SCSIRequest *req;
615     SCSICommand cmd = { .len = 0 };
616     int ret;
617 
618     if ((d->unit_attention.key == UNIT_ATTENTION ||
619          bus->unit_attention.key == UNIT_ATTENTION) &&
620         (buf[0] != INQUIRY &&
621          buf[0] != REPORT_LUNS &&
622          buf[0] != GET_CONFIGURATION &&
623          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
624 
625          /*
626           * If we already have a pending unit attention condition,
627           * report this one before triggering another one.
628           */
629          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
630         ops = &reqops_unit_attention;
631     } else if (lun != d->lun ||
632                buf[0] == REPORT_LUNS ||
633                (buf[0] == REQUEST_SENSE && d->sense_len)) {
634         ops = &reqops_target_command;
635     } else {
636         ops = NULL;
637     }
638 
639     if (ops != NULL || !sc->parse_cdb) {
640         ret = scsi_req_parse_cdb(d, &cmd, buf);
641     } else {
642         ret = sc->parse_cdb(d, &cmd, buf, hba_private);
643     }
644 
645     if (ret != 0) {
646         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
647         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
648     } else {
649         assert(cmd.len != 0);
650         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
651                               cmd.mode, cmd.xfer);
652         if (cmd.lba != -1) {
653             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
654                                       cmd.lba);
655         }
656 
657         if (cmd.xfer > INT32_MAX) {
658             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
659         } else if (ops) {
660             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
661         } else {
662             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
663         }
664     }
665 
666     req->cmd = cmd;
667     req->resid = req->cmd.xfer;
668 
669     switch (buf[0]) {
670     case INQUIRY:
671         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
672         break;
673     case TEST_UNIT_READY:
674         trace_scsi_test_unit_ready(d->id, lun, tag);
675         break;
676     case REPORT_LUNS:
677         trace_scsi_report_luns(d->id, lun, tag);
678         break;
679     case REQUEST_SENSE:
680         trace_scsi_request_sense(d->id, lun, tag);
681         break;
682     default:
683         break;
684     }
685 
686     return req;
687 }
688 
689 uint8_t *scsi_req_get_buf(SCSIRequest *req)
690 {
691     return req->ops->get_buf(req);
692 }
693 
694 static void scsi_clear_unit_attention(SCSIRequest *req)
695 {
696     SCSISense *ua;
697     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
698         req->bus->unit_attention.key != UNIT_ATTENTION) {
699         return;
700     }
701 
702     /*
703      * If an INQUIRY command enters the enabled command state,
704      * the device server shall [not] clear any unit attention condition;
705      * See also MMC-6, paragraphs 6.5 and 6.6.2.
706      */
707     if (req->cmd.buf[0] == INQUIRY ||
708         req->cmd.buf[0] == GET_CONFIGURATION ||
709         req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
710         return;
711     }
712 
713     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
714         ua = &req->dev->unit_attention;
715     } else {
716         ua = &req->bus->unit_attention;
717     }
718 
719     /*
720      * If a REPORT LUNS command enters the enabled command state, [...]
721      * the device server shall clear any pending unit attention condition
722      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
723      */
724     if (req->cmd.buf[0] == REPORT_LUNS &&
725         !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
726           ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
727         return;
728     }
729 
730     *ua = SENSE_CODE(NO_SENSE);
731 }
732 
733 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
734 {
735     int ret;
736 
737     assert(len >= 14);
738     if (!req->sense_len) {
739         return 0;
740     }
741 
742     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
743 
744     /*
745      * FIXME: clearing unit attention conditions upon autosense should be done
746      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
747      * (SAM-5, 5.14).
748      *
749      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
750      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
751      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
752      */
753     if (req->dev->sense_is_ua) {
754         scsi_device_unit_attention_reported(req->dev);
755         req->dev->sense_len = 0;
756         req->dev->sense_is_ua = false;
757     }
758     return ret;
759 }
760 
761 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
762 {
763     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
764 }
765 
766 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
767 {
768     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
769                                sense.key, sense.asc, sense.ascq);
770     req->sense_len = scsi_build_sense(req->sense, sense);
771 }
772 
773 static void scsi_req_enqueue_internal(SCSIRequest *req)
774 {
775     assert(!req->enqueued);
776     scsi_req_ref(req);
777     if (req->bus->info->get_sg_list) {
778         req->sg = req->bus->info->get_sg_list(req);
779     } else {
780         req->sg = NULL;
781     }
782     req->enqueued = true;
783     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
784 }
785 
786 int32_t scsi_req_enqueue(SCSIRequest *req)
787 {
788     int32_t rc;
789 
790     assert(!req->retry);
791     scsi_req_enqueue_internal(req);
792     scsi_req_ref(req);
793     rc = req->ops->send_command(req, req->cmd.buf);
794     scsi_req_unref(req);
795     return rc;
796 }
797 
798 static void scsi_req_dequeue(SCSIRequest *req)
799 {
800     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
801     req->retry = false;
802     if (req->enqueued) {
803         QTAILQ_REMOVE(&req->dev->requests, req, next);
804         req->enqueued = false;
805         scsi_req_unref(req);
806     }
807 }
808 
809 static int scsi_get_performance_length(int num_desc, int type, int data_type)
810 {
811     /* MMC-6, paragraph 6.7.  */
812     switch (type) {
813     case 0:
814         if ((data_type & 3) == 0) {
815             /* Each descriptor is as in Table 295 - Nominal performance.  */
816             return 16 * num_desc + 8;
817         } else {
818             /* Each descriptor is as in Table 296 - Exceptions.  */
819             return 6 * num_desc + 8;
820         }
821     case 1:
822     case 4:
823     case 5:
824         return 8 * num_desc + 8;
825     case 2:
826         return 2048 * num_desc + 8;
827     case 3:
828         return 16 * num_desc + 8;
829     default:
830         return 8;
831     }
832 }
833 
834 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
835 {
836     int byte_block = (buf[2] >> 2) & 0x1;
837     int type = (buf[2] >> 4) & 0x1;
838     int xfer_unit;
839 
840     if (byte_block) {
841         if (type) {
842             xfer_unit = dev->blocksize;
843         } else {
844             xfer_unit = 512;
845         }
846     } else {
847         xfer_unit = 1;
848     }
849 
850     return xfer_unit;
851 }
852 
853 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
854 {
855     int length = buf[2] & 0x3;
856     int xfer;
857     int unit = ata_passthrough_xfer_unit(dev, buf);
858 
859     switch (length) {
860     case 0:
861     case 3: /* USB-specific.  */
862     default:
863         xfer = 0;
864         break;
865     case 1:
866         xfer = buf[3];
867         break;
868     case 2:
869         xfer = buf[4];
870         break;
871     }
872 
873     return xfer * unit;
874 }
875 
876 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
877 {
878     int extend = buf[1] & 0x1;
879     int length = buf[2] & 0x3;
880     int xfer;
881     int unit = ata_passthrough_xfer_unit(dev, buf);
882 
883     switch (length) {
884     case 0:
885     case 3: /* USB-specific.  */
886     default:
887         xfer = 0;
888         break;
889     case 1:
890         xfer = buf[4];
891         xfer |= (extend ? buf[3] << 8 : 0);
892         break;
893     case 2:
894         xfer = buf[6];
895         xfer |= (extend ? buf[5] << 8 : 0);
896         break;
897     }
898 
899     return xfer * unit;
900 }
901 
902 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
903 {
904     cmd->xfer = scsi_cdb_xfer(buf);
905     switch (buf[0]) {
906     case TEST_UNIT_READY:
907     case REWIND:
908     case START_STOP:
909     case SET_CAPACITY:
910     case WRITE_FILEMARKS:
911     case WRITE_FILEMARKS_16:
912     case SPACE:
913     case RESERVE:
914     case RELEASE:
915     case ERASE:
916     case ALLOW_MEDIUM_REMOVAL:
917     case SEEK_10:
918     case SYNCHRONIZE_CACHE:
919     case SYNCHRONIZE_CACHE_16:
920     case LOCATE_16:
921     case LOCK_UNLOCK_CACHE:
922     case SET_CD_SPEED:
923     case SET_LIMITS:
924     case WRITE_LONG_10:
925     case UPDATE_BLOCK:
926     case RESERVE_TRACK:
927     case SET_READ_AHEAD:
928     case PRE_FETCH:
929     case PRE_FETCH_16:
930     case ALLOW_OVERWRITE:
931         cmd->xfer = 0;
932         break;
933     case VERIFY_10:
934     case VERIFY_12:
935     case VERIFY_16:
936         if ((buf[1] & 2) == 0) {
937             cmd->xfer = 0;
938         } else if ((buf[1] & 4) != 0) {
939             cmd->xfer = 1;
940         }
941         cmd->xfer *= dev->blocksize;
942         break;
943     case MODE_SENSE:
944         break;
945     case WRITE_SAME_10:
946     case WRITE_SAME_16:
947         cmd->xfer = dev->blocksize;
948         break;
949     case READ_CAPACITY_10:
950         cmd->xfer = 8;
951         break;
952     case READ_BLOCK_LIMITS:
953         cmd->xfer = 6;
954         break;
955     case SEND_VOLUME_TAG:
956         /* GPCMD_SET_STREAMING from multimedia commands.  */
957         if (dev->type == TYPE_ROM) {
958             cmd->xfer = buf[10] | (buf[9] << 8);
959         } else {
960             cmd->xfer = buf[9] | (buf[8] << 8);
961         }
962         break;
963     case WRITE_6:
964         /* length 0 means 256 blocks */
965         if (cmd->xfer == 0) {
966             cmd->xfer = 256;
967         }
968         /* fall through */
969     case WRITE_10:
970     case WRITE_VERIFY_10:
971     case WRITE_12:
972     case WRITE_VERIFY_12:
973     case WRITE_16:
974     case WRITE_VERIFY_16:
975         cmd->xfer *= dev->blocksize;
976         break;
977     case READ_6:
978     case READ_REVERSE:
979         /* length 0 means 256 blocks */
980         if (cmd->xfer == 0) {
981             cmd->xfer = 256;
982         }
983         /* fall through */
984     case READ_10:
985     case READ_12:
986     case READ_16:
987         cmd->xfer *= dev->blocksize;
988         break;
989     case FORMAT_UNIT:
990         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
991          * for block devices are restricted to the header right now.  */
992         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
993             cmd->xfer = 12;
994         } else {
995             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
996         }
997         break;
998     case INQUIRY:
999     case RECEIVE_DIAGNOSTIC:
1000     case SEND_DIAGNOSTIC:
1001         cmd->xfer = buf[4] | (buf[3] << 8);
1002         break;
1003     case READ_CD:
1004     case READ_BUFFER:
1005     case WRITE_BUFFER:
1006     case SEND_CUE_SHEET:
1007         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1008         break;
1009     case PERSISTENT_RESERVE_OUT:
1010         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1011         break;
1012     case ERASE_12:
1013         if (dev->type == TYPE_ROM) {
1014             /* MMC command GET PERFORMANCE.  */
1015             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1016                                                     buf[10], buf[1] & 0x1f);
1017         }
1018         break;
1019     case MECHANISM_STATUS:
1020     case READ_DVD_STRUCTURE:
1021     case SEND_DVD_STRUCTURE:
1022     case MAINTENANCE_OUT:
1023     case MAINTENANCE_IN:
1024         if (dev->type == TYPE_ROM) {
1025             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1026             cmd->xfer = buf[9] | (buf[8] << 8);
1027         }
1028         break;
1029     case ATA_PASSTHROUGH_12:
1030         if (dev->type == TYPE_ROM) {
1031             /* BLANK command of MMC */
1032             cmd->xfer = 0;
1033         } else {
1034             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1035         }
1036         break;
1037     case ATA_PASSTHROUGH_16:
1038         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1039         break;
1040     }
1041     return 0;
1042 }
1043 
1044 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1045 {
1046     switch (buf[0]) {
1047     /* stream commands */
1048     case ERASE_12:
1049     case ERASE_16:
1050         cmd->xfer = 0;
1051         break;
1052     case READ_6:
1053     case READ_REVERSE:
1054     case RECOVER_BUFFERED_DATA:
1055     case WRITE_6:
1056         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1057         if (buf[1] & 0x01) { /* fixed */
1058             cmd->xfer *= dev->blocksize;
1059         }
1060         break;
1061     case READ_16:
1062     case READ_REVERSE_16:
1063     case VERIFY_16:
1064     case WRITE_16:
1065         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1066         if (buf[1] & 0x01) { /* fixed */
1067             cmd->xfer *= dev->blocksize;
1068         }
1069         break;
1070     case REWIND:
1071     case LOAD_UNLOAD:
1072         cmd->xfer = 0;
1073         break;
1074     case SPACE_16:
1075         cmd->xfer = buf[13] | (buf[12] << 8);
1076         break;
1077     case READ_POSITION:
1078         switch (buf[1] & 0x1f) /* operation code */ {
1079         case SHORT_FORM_BLOCK_ID:
1080         case SHORT_FORM_VENDOR_SPECIFIC:
1081             cmd->xfer = 20;
1082             break;
1083         case LONG_FORM:
1084             cmd->xfer = 32;
1085             break;
1086         case EXTENDED_FORM:
1087             cmd->xfer = buf[8] | (buf[7] << 8);
1088             break;
1089         default:
1090             return -1;
1091         }
1092 
1093         break;
1094     case FORMAT_UNIT:
1095         cmd->xfer = buf[4] | (buf[3] << 8);
1096         break;
1097     /* generic commands */
1098     default:
1099         return scsi_req_xfer(cmd, dev, buf);
1100     }
1101     return 0;
1102 }
1103 
1104 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1105 {
1106     switch (buf[0]) {
1107     /* medium changer commands */
1108     case EXCHANGE_MEDIUM:
1109     case INITIALIZE_ELEMENT_STATUS:
1110     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1111     case MOVE_MEDIUM:
1112     case POSITION_TO_ELEMENT:
1113         cmd->xfer = 0;
1114         break;
1115     case READ_ELEMENT_STATUS:
1116         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1117         break;
1118 
1119     /* generic commands */
1120     default:
1121         return scsi_req_xfer(cmd, dev, buf);
1122     }
1123     return 0;
1124 }
1125 
1126 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1127 {
1128     switch (buf[0]) {
1129     /* Scanner commands */
1130     case OBJECT_POSITION:
1131         cmd->xfer = 0;
1132         break;
1133     case SCAN:
1134         cmd->xfer = buf[4];
1135         break;
1136     case READ_10:
1137     case SEND:
1138     case GET_WINDOW:
1139     case SET_WINDOW:
1140         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1141         break;
1142     default:
1143         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1144         return scsi_req_xfer(cmd, dev, buf);
1145     }
1146 
1147     return 0;
1148 }
1149 
1150 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1151 {
1152     if (!cmd->xfer) {
1153         cmd->mode = SCSI_XFER_NONE;
1154         return;
1155     }
1156     switch (cmd->buf[0]) {
1157     case WRITE_6:
1158     case WRITE_10:
1159     case WRITE_VERIFY_10:
1160     case WRITE_12:
1161     case WRITE_VERIFY_12:
1162     case WRITE_16:
1163     case WRITE_VERIFY_16:
1164     case VERIFY_10:
1165     case VERIFY_12:
1166     case VERIFY_16:
1167     case COPY:
1168     case COPY_VERIFY:
1169     case COMPARE:
1170     case CHANGE_DEFINITION:
1171     case LOG_SELECT:
1172     case MODE_SELECT:
1173     case MODE_SELECT_10:
1174     case SEND_DIAGNOSTIC:
1175     case WRITE_BUFFER:
1176     case FORMAT_UNIT:
1177     case REASSIGN_BLOCKS:
1178     case SEARCH_EQUAL:
1179     case SEARCH_HIGH:
1180     case SEARCH_LOW:
1181     case UPDATE_BLOCK:
1182     case WRITE_LONG_10:
1183     case WRITE_SAME_10:
1184     case WRITE_SAME_16:
1185     case UNMAP:
1186     case SEARCH_HIGH_12:
1187     case SEARCH_EQUAL_12:
1188     case SEARCH_LOW_12:
1189     case MEDIUM_SCAN:
1190     case SEND_VOLUME_TAG:
1191     case SEND_CUE_SHEET:
1192     case SEND_DVD_STRUCTURE:
1193     case PERSISTENT_RESERVE_OUT:
1194     case MAINTENANCE_OUT:
1195     case SET_WINDOW:
1196     case SCAN:
1197         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1198          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1199          */
1200         cmd->mode = SCSI_XFER_TO_DEV;
1201         break;
1202     case ATA_PASSTHROUGH_12:
1203     case ATA_PASSTHROUGH_16:
1204         /* T_DIR */
1205         cmd->mode = (cmd->buf[2] & 0x8) ?
1206                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1207         break;
1208     default:
1209         cmd->mode = SCSI_XFER_FROM_DEV;
1210         break;
1211     }
1212 }
1213 
1214 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf)
1215 {
1216     int rc;
1217     int len;
1218 
1219     cmd->lba = -1;
1220     len = scsi_cdb_length(buf);
1221     if (len < 0) {
1222         return -1;
1223     }
1224 
1225     cmd->len = len;
1226     switch (dev->type) {
1227     case TYPE_TAPE:
1228         rc = scsi_req_stream_xfer(cmd, dev, buf);
1229         break;
1230     case TYPE_MEDIUM_CHANGER:
1231         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1232         break;
1233     case TYPE_SCANNER:
1234         rc = scsi_req_scanner_length(cmd, dev, buf);
1235         break;
1236     default:
1237         rc = scsi_req_xfer(cmd, dev, buf);
1238         break;
1239     }
1240 
1241     if (rc != 0)
1242         return rc;
1243 
1244     memcpy(cmd->buf, buf, cmd->len);
1245     scsi_cmd_xfer_mode(cmd);
1246     cmd->lba = scsi_cmd_lba(cmd);
1247     return 0;
1248 }
1249 
1250 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1251 {
1252     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1253 
1254     scsi_device_set_ua(dev, sense);
1255     if (bus->info->change) {
1256         bus->info->change(bus, dev, sense);
1257     }
1258 }
1259 
1260 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1261 {
1262     assert(req->refcount > 0);
1263     req->refcount++;
1264     return req;
1265 }
1266 
1267 void scsi_req_unref(SCSIRequest *req)
1268 {
1269     assert(req->refcount > 0);
1270     if (--req->refcount == 0) {
1271         BusState *qbus = req->dev->qdev.parent_bus;
1272         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1273 
1274         if (bus->info->free_request && req->hba_private) {
1275             bus->info->free_request(bus, req->hba_private);
1276         }
1277         if (req->ops->free_req) {
1278             req->ops->free_req(req);
1279         }
1280         object_unref(OBJECT(req->dev));
1281         object_unref(OBJECT(qbus->parent));
1282         g_free(req);
1283     }
1284 }
1285 
1286 /* Tell the device that we finished processing this chunk of I/O.  It
1287    will start the next chunk or complete the command.  */
1288 void scsi_req_continue(SCSIRequest *req)
1289 {
1290     if (req->io_canceled) {
1291         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1292         return;
1293     }
1294     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1295     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1296         req->ops->write_data(req);
1297     } else {
1298         req->ops->read_data(req);
1299     }
1300 }
1301 
1302 /* Called by the devices when data is ready for the HBA.  The HBA should
1303    start a DMA operation to read or fill the device's data buffer.
1304    Once it completes, calling scsi_req_continue will restart I/O.  */
1305 void scsi_req_data(SCSIRequest *req, int len)
1306 {
1307     uint8_t *buf;
1308     if (req->io_canceled) {
1309         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1310         return;
1311     }
1312     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1313     assert(req->cmd.mode != SCSI_XFER_NONE);
1314     if (!req->sg) {
1315         req->resid -= len;
1316         req->bus->info->transfer_data(req, len);
1317         return;
1318     }
1319 
1320     /* If the device calls scsi_req_data and the HBA specified a
1321      * scatter/gather list, the transfer has to happen in a single
1322      * step.  */
1323     assert(!req->dma_started);
1324     req->dma_started = true;
1325 
1326     buf = scsi_req_get_buf(req);
1327     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1328         req->resid = dma_buf_read(buf, len, req->sg);
1329     } else {
1330         req->resid = dma_buf_write(buf, len, req->sg);
1331     }
1332     scsi_req_continue(req);
1333 }
1334 
1335 void scsi_req_print(SCSIRequest *req)
1336 {
1337     FILE *fp = stderr;
1338     int i;
1339 
1340     fprintf(fp, "[%s id=%d] %s",
1341             req->dev->qdev.parent_bus->name,
1342             req->dev->id,
1343             scsi_command_name(req->cmd.buf[0]));
1344     for (i = 1; i < req->cmd.len; i++) {
1345         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1346     }
1347     switch (req->cmd.mode) {
1348     case SCSI_XFER_NONE:
1349         fprintf(fp, " - none\n");
1350         break;
1351     case SCSI_XFER_FROM_DEV:
1352         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1353         break;
1354     case SCSI_XFER_TO_DEV:
1355         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1356         break;
1357     default:
1358         fprintf(fp, " - Oops\n");
1359         break;
1360     }
1361 }
1362 
1363 void scsi_req_complete(SCSIRequest *req, int status)
1364 {
1365     assert(req->status == -1);
1366     req->status = status;
1367 
1368     assert(req->sense_len <= sizeof(req->sense));
1369     if (status == GOOD) {
1370         req->sense_len = 0;
1371     }
1372 
1373     if (req->sense_len) {
1374         memcpy(req->dev->sense, req->sense, req->sense_len);
1375         req->dev->sense_len = req->sense_len;
1376         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1377     } else {
1378         req->dev->sense_len = 0;
1379         req->dev->sense_is_ua = false;
1380     }
1381 
1382     /*
1383      * Unit attention state is now stored in the device's sense buffer
1384      * if the HBA didn't do autosense.  Clear the pending unit attention
1385      * flags.
1386      */
1387     scsi_clear_unit_attention(req);
1388 
1389     scsi_req_ref(req);
1390     scsi_req_dequeue(req);
1391     req->bus->info->complete(req, req->status, req->resid);
1392 
1393     /* Cancelled requests might end up being completed instead of cancelled */
1394     notifier_list_notify(&req->cancel_notifiers, req);
1395     scsi_req_unref(req);
1396 }
1397 
1398 /* Called by the devices when the request is canceled. */
1399 void scsi_req_cancel_complete(SCSIRequest *req)
1400 {
1401     assert(req->io_canceled);
1402     if (req->bus->info->cancel) {
1403         req->bus->info->cancel(req);
1404     }
1405     notifier_list_notify(&req->cancel_notifiers, req);
1406     scsi_req_unref(req);
1407 }
1408 
1409 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1410  * notifier list, the bus will be notified the requests cancellation is
1411  * completed.
1412  * */
1413 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1414 {
1415     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1416     if (notifier) {
1417         notifier_list_add(&req->cancel_notifiers, notifier);
1418     }
1419     if (req->io_canceled) {
1420         /* A blk_aio_cancel_async is pending; when it finishes,
1421          * scsi_req_cancel_complete will be called and will
1422          * call the notifier we just added.  Just wait for that.
1423          */
1424         assert(req->aiocb);
1425         return;
1426     }
1427     /* Dropped in scsi_req_cancel_complete.  */
1428     scsi_req_ref(req);
1429     scsi_req_dequeue(req);
1430     req->io_canceled = true;
1431     if (req->aiocb) {
1432         blk_aio_cancel_async(req->aiocb);
1433     } else {
1434         scsi_req_cancel_complete(req);
1435     }
1436 }
1437 
1438 void scsi_req_cancel(SCSIRequest *req)
1439 {
1440     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1441     if (!req->enqueued) {
1442         return;
1443     }
1444     assert(!req->io_canceled);
1445     /* Dropped in scsi_req_cancel_complete.  */
1446     scsi_req_ref(req);
1447     scsi_req_dequeue(req);
1448     req->io_canceled = true;
1449     if (req->aiocb) {
1450         blk_aio_cancel(req->aiocb);
1451     } else {
1452         scsi_req_cancel_complete(req);
1453     }
1454 }
1455 
1456 static int scsi_ua_precedence(SCSISense sense)
1457 {
1458     if (sense.key != UNIT_ATTENTION) {
1459         return INT_MAX;
1460     }
1461     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1462         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1463         return 1;
1464     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1465         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1466         return 2;
1467     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1468         /* These two go with "all others". */
1469         ;
1470     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1471         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1472          * POWER ON OCCURRED = 1
1473          * SCSI BUS RESET OCCURRED = 2
1474          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1475          * I_T NEXUS LOSS OCCURRED = 7
1476          */
1477         return sense.ascq;
1478     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1479         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1480         return 8;
1481     }
1482     return (sense.asc << 8) | sense.ascq;
1483 }
1484 
1485 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1486 {
1487     int prec1, prec2;
1488     if (sense.key != UNIT_ATTENTION) {
1489         return;
1490     }
1491     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1492                              sense.asc, sense.ascq);
1493 
1494     /*
1495      * Override a pre-existing unit attention condition, except for a more
1496      * important reset condition.
1497     */
1498     prec1 = scsi_ua_precedence(sdev->unit_attention);
1499     prec2 = scsi_ua_precedence(sense);
1500     if (prec2 < prec1) {
1501         sdev->unit_attention = sense;
1502     }
1503 }
1504 
1505 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1506 {
1507     SCSIRequest *req;
1508 
1509     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1510     while (!QTAILQ_EMPTY(&sdev->requests)) {
1511         req = QTAILQ_FIRST(&sdev->requests);
1512         scsi_req_cancel_async(req, NULL);
1513     }
1514     blk_drain(sdev->conf.blk);
1515     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1516     scsi_device_set_ua(sdev, sense);
1517 }
1518 
1519 static char *scsibus_get_dev_path(DeviceState *dev)
1520 {
1521     SCSIDevice *d = SCSI_DEVICE(dev);
1522     DeviceState *hba = dev->parent_bus->parent;
1523     char *id;
1524     char *path;
1525 
1526     id = qdev_get_dev_path(hba);
1527     if (id) {
1528         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1529     } else {
1530         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1531     }
1532     g_free(id);
1533     return path;
1534 }
1535 
1536 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1537 {
1538     SCSIDevice *d = SCSI_DEVICE(dev);
1539     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1540                            qdev_fw_name(dev), d->id, d->lun);
1541 }
1542 
1543 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
1544 {
1545     BusChild *kid;
1546     SCSIDevice *target_dev = NULL;
1547 
1548     QTAILQ_FOREACH_REVERSE(kid, &bus->qbus.children, ChildrenHead, sibling) {
1549         DeviceState *qdev = kid->child;
1550         SCSIDevice *dev = SCSI_DEVICE(qdev);
1551 
1552         if (dev->channel == channel && dev->id == id) {
1553             if (dev->lun == lun) {
1554                 return dev;
1555             }
1556             target_dev = dev;
1557         }
1558     }
1559     return target_dev;
1560 }
1561 
1562 /* SCSI request list.  For simplicity, pv points to the whole device */
1563 
1564 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1565                              VMStateField *field, QJSON *vmdesc)
1566 {
1567     SCSIDevice *s = pv;
1568     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1569     SCSIRequest *req;
1570 
1571     QTAILQ_FOREACH(req, &s->requests, next) {
1572         assert(!req->io_canceled);
1573         assert(req->status == -1);
1574         assert(req->enqueued);
1575 
1576         qemu_put_sbyte(f, req->retry ? 1 : 2);
1577         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1578         qemu_put_be32s(f, &req->tag);
1579         qemu_put_be32s(f, &req->lun);
1580         if (bus->info->save_request) {
1581             bus->info->save_request(f, req);
1582         }
1583         if (req->ops->save_request) {
1584             req->ops->save_request(f, req);
1585         }
1586     }
1587     qemu_put_sbyte(f, 0);
1588 
1589     return 0;
1590 }
1591 
1592 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1593                              VMStateField *field)
1594 {
1595     SCSIDevice *s = pv;
1596     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1597     int8_t sbyte;
1598 
1599     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1600         uint8_t buf[SCSI_CMD_BUF_SIZE];
1601         uint32_t tag;
1602         uint32_t lun;
1603         SCSIRequest *req;
1604 
1605         qemu_get_buffer(f, buf, sizeof(buf));
1606         qemu_get_be32s(f, &tag);
1607         qemu_get_be32s(f, &lun);
1608         req = scsi_req_new(s, tag, lun, buf, NULL);
1609         req->retry = (sbyte == 1);
1610         if (bus->info->load_request) {
1611             req->hba_private = bus->info->load_request(f, req);
1612         }
1613         if (req->ops->load_request) {
1614             req->ops->load_request(f, req);
1615         }
1616 
1617         /* Just restart it later.  */
1618         scsi_req_enqueue_internal(req);
1619 
1620         /* At this point, the request will be kept alive by the reference
1621          * added by scsi_req_enqueue_internal, so we can release our reference.
1622          * The HBA of course will add its own reference in the load_request
1623          * callback if it needs to hold on the SCSIRequest.
1624          */
1625         scsi_req_unref(req);
1626     }
1627 
1628     return 0;
1629 }
1630 
1631 static const VMStateInfo vmstate_info_scsi_requests = {
1632     .name = "scsi-requests",
1633     .get  = get_scsi_requests,
1634     .put  = put_scsi_requests,
1635 };
1636 
1637 static bool scsi_sense_state_needed(void *opaque)
1638 {
1639     SCSIDevice *s = opaque;
1640 
1641     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1642 }
1643 
1644 static const VMStateDescription vmstate_scsi_sense_state = {
1645     .name = "SCSIDevice/sense",
1646     .version_id = 1,
1647     .minimum_version_id = 1,
1648     .needed = scsi_sense_state_needed,
1649     .fields = (VMStateField[]) {
1650         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1651                                 SCSI_SENSE_BUF_SIZE_OLD,
1652                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1653         VMSTATE_END_OF_LIST()
1654     }
1655 };
1656 
1657 const VMStateDescription vmstate_scsi_device = {
1658     .name = "SCSIDevice",
1659     .version_id = 1,
1660     .minimum_version_id = 1,
1661     .fields = (VMStateField[]) {
1662         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1663         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1664         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1665         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1666         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1667         VMSTATE_UINT32(sense_len, SCSIDevice),
1668         {
1669             .name         = "requests",
1670             .version_id   = 0,
1671             .field_exists = NULL,
1672             .size         = 0,   /* ouch */
1673             .info         = &vmstate_info_scsi_requests,
1674             .flags        = VMS_SINGLE,
1675             .offset       = 0,
1676         },
1677         VMSTATE_END_OF_LIST()
1678     },
1679     .subsections = (const VMStateDescription*[]) {
1680         &vmstate_scsi_sense_state,
1681         NULL
1682     }
1683 };
1684 
1685 static void scsi_device_class_init(ObjectClass *klass, void *data)
1686 {
1687     DeviceClass *k = DEVICE_CLASS(klass);
1688     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1689     k->bus_type  = TYPE_SCSI_BUS;
1690     k->realize   = scsi_qdev_realize;
1691     k->unrealize = scsi_qdev_unrealize;
1692     k->props     = scsi_props;
1693 }
1694 
1695 static void scsi_dev_instance_init(Object *obj)
1696 {
1697     DeviceState *dev = DEVICE(obj);
1698     SCSIDevice *s = SCSI_DEVICE(dev);
1699 
1700     device_add_bootindex_property(obj, &s->conf.bootindex,
1701                                   "bootindex", NULL,
1702                                   &s->qdev, NULL);
1703 }
1704 
1705 static const TypeInfo scsi_device_type_info = {
1706     .name = TYPE_SCSI_DEVICE,
1707     .parent = TYPE_DEVICE,
1708     .instance_size = sizeof(SCSIDevice),
1709     .abstract = true,
1710     .class_size = sizeof(SCSIDeviceClass),
1711     .class_init = scsi_device_class_init,
1712     .instance_init = scsi_dev_instance_init,
1713 };
1714 
1715 static void scsi_register_types(void)
1716 {
1717     type_register_static(&scsi_bus_info);
1718     type_register_static(&scsi_device_type_info);
1719 }
1720 
1721 type_init(scsi_register_types)
1722