xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision de15df5e)
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 Property scsi_props[] = {
26     DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
27     DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
28     DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
29     DEFINE_PROP_END_OF_LIST(),
30 };
31 
32 static void scsi_bus_class_init(ObjectClass *klass, void *data)
33 {
34     BusClass *k = BUS_CLASS(klass);
35     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
36 
37     k->get_dev_path = scsibus_get_dev_path;
38     k->get_fw_dev_path = scsibus_get_fw_dev_path;
39     hc->unplug = qdev_simple_device_unplug_cb;
40 }
41 
42 static const TypeInfo scsi_bus_info = {
43     .name = TYPE_SCSI_BUS,
44     .parent = TYPE_BUS,
45     .instance_size = sizeof(SCSIBus),
46     .class_init = scsi_bus_class_init,
47     .interfaces = (InterfaceInfo[]) {
48         { TYPE_HOTPLUG_HANDLER },
49         { }
50     }
51 };
52 static int next_scsi_bus;
53 
54 static void scsi_device_realize(SCSIDevice *s, Error **errp)
55 {
56     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
57     if (sc->realize) {
58         sc->realize(s, errp);
59     }
60 }
61 
62 static void scsi_device_unrealize(SCSIDevice *s)
63 {
64     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
65     if (sc->unrealize) {
66         sc->unrealize(s);
67     }
68 }
69 
70 int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
71                        void *hba_private)
72 {
73     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
74     int rc;
75 
76     assert(cmd->len == 0);
77     rc = scsi_req_parse_cdb(dev, cmd, buf);
78     if (bus->info->parse_cdb) {
79         rc = bus->info->parse_cdb(dev, cmd, buf, hba_private);
80     }
81     return rc;
82 }
83 
84 static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
85                                           uint8_t *buf, void *hba_private)
86 {
87     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
88     if (sc->alloc_req) {
89         return sc->alloc_req(s, tag, lun, buf, hba_private);
90     }
91 
92     return NULL;
93 }
94 
95 void scsi_device_unit_attention_reported(SCSIDevice *s)
96 {
97     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
98     if (sc->unit_attention_reported) {
99         sc->unit_attention_reported(s);
100     }
101 }
102 
103 /* Create a scsi bus, and attach devices to it.  */
104 void scsi_bus_new(SCSIBus *bus, size_t bus_size, DeviceState *host,
105                   const SCSIBusInfo *info, const char *bus_name)
106 {
107     qbus_create_inplace(bus, bus_size, TYPE_SCSI_BUS, host, bus_name);
108     bus->busnr = next_scsi_bus++;
109     bus->info = info;
110     qbus_set_bus_hotplug_handler(BUS(bus), &error_abort);
111 }
112 
113 static void scsi_dma_restart_bh(void *opaque)
114 {
115     SCSIDevice *s = opaque;
116     SCSIRequest *req, *next;
117 
118     qemu_bh_delete(s->bh);
119     s->bh = NULL;
120 
121     aio_context_acquire(blk_get_aio_context(s->conf.blk));
122     QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
123         scsi_req_ref(req);
124         if (req->retry) {
125             req->retry = false;
126             switch (req->cmd.mode) {
127             case SCSI_XFER_FROM_DEV:
128             case SCSI_XFER_TO_DEV:
129                 scsi_req_continue(req);
130                 break;
131             case SCSI_XFER_NONE:
132                 scsi_req_dequeue(req);
133                 scsi_req_enqueue(req);
134                 break;
135             }
136         }
137         scsi_req_unref(req);
138     }
139     aio_context_release(blk_get_aio_context(s->conf.blk));
140 }
141 
142 void scsi_req_retry(SCSIRequest *req)
143 {
144     /* No need to save a reference, because scsi_dma_restart_bh just
145      * looks at the request list.  */
146     req->retry = true;
147 }
148 
149 static void scsi_dma_restart_cb(void *opaque, int running, RunState state)
150 {
151     SCSIDevice *s = opaque;
152 
153     if (!running) {
154         return;
155     }
156     if (!s->bh) {
157         AioContext *ctx = blk_get_aio_context(s->conf.blk);
158         s->bh = aio_bh_new(ctx, scsi_dma_restart_bh, s);
159         qemu_bh_schedule(s->bh);
160     }
161 }
162 
163 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
164 {
165     SCSIDevice *dev = SCSI_DEVICE(qdev);
166     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
167     SCSIDevice *d;
168     Error *local_err = NULL;
169 
170     if (dev->channel > bus->info->max_channel) {
171         error_setg(errp, "bad scsi channel id: %d", dev->channel);
172         return;
173     }
174     if (dev->id != -1 && dev->id > bus->info->max_target) {
175         error_setg(errp, "bad scsi device id: %d", dev->id);
176         return;
177     }
178     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
179         error_setg(errp, "bad scsi device lun: %d", dev->lun);
180         return;
181     }
182 
183     if (dev->id == -1) {
184         int id = -1;
185         if (dev->lun == -1) {
186             dev->lun = 0;
187         }
188         do {
189             d = scsi_device_find(bus, dev->channel, ++id, dev->lun);
190         } while (d && d->lun == dev->lun && id < bus->info->max_target);
191         if (d && d->lun == dev->lun) {
192             error_setg(errp, "no free target");
193             return;
194         }
195         dev->id = id;
196     } else if (dev->lun == -1) {
197         int lun = -1;
198         do {
199             d = scsi_device_find(bus, dev->channel, dev->id, ++lun);
200         } while (d && d->lun == lun && lun < bus->info->max_lun);
201         if (d && d->lun == lun) {
202             error_setg(errp, "no free lun");
203             return;
204         }
205         dev->lun = lun;
206     } else {
207         d = scsi_device_find(bus, dev->channel, dev->id, dev->lun);
208         assert(d);
209         if (d->lun == dev->lun && dev != d) {
210             error_setg(errp, "lun already used by '%s'", d->qdev.id);
211             return;
212         }
213     }
214 
215     QTAILQ_INIT(&dev->requests);
216     scsi_device_realize(dev, &local_err);
217     if (local_err) {
218         error_propagate(errp, local_err);
219         return;
220     }
221     dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
222             scsi_dma_restart_cb, dev);
223 }
224 
225 static void scsi_qdev_unrealize(DeviceState *qdev)
226 {
227     SCSIDevice *dev = SCSI_DEVICE(qdev);
228 
229     if (dev->vmsentry) {
230         qemu_del_vm_change_state_handler(dev->vmsentry);
231     }
232 
233     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
234 
235     scsi_device_unrealize(dev);
236 
237     blockdev_mark_auto_del(dev->conf.blk);
238 }
239 
240 /* handle legacy '-drive if=scsi,...' cmd line args */
241 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
242                                       int unit, bool removable, int bootindex,
243                                       bool share_rw,
244                                       BlockdevOnError rerror,
245                                       BlockdevOnError werror,
246                                       const char *serial, Error **errp)
247 {
248     const char *driver;
249     char *name;
250     DeviceState *dev;
251     Error *err = NULL;
252     DriveInfo *dinfo;
253 
254     if (blk_is_sg(blk)) {
255         driver = "scsi-generic";
256     } else {
257         dinfo = blk_legacy_dinfo(blk);
258         if (dinfo && dinfo->media_cd) {
259             driver = "scsi-cd";
260         } else {
261             driver = "scsi-hd";
262         }
263     }
264     dev = qdev_new(driver);
265     name = g_strdup_printf("legacy[%d]", unit);
266     object_property_add_child(OBJECT(bus), name, OBJECT(dev));
267     g_free(name);
268 
269     qdev_prop_set_uint32(dev, "scsi-id", unit);
270     if (bootindex >= 0) {
271         object_property_set_int(OBJECT(dev), bootindex, "bootindex",
272                                 &error_abort);
273     }
274     if (object_property_find(OBJECT(dev), "removable", NULL)) {
275         qdev_prop_set_bit(dev, "removable", removable);
276     }
277     if (serial && object_property_find(OBJECT(dev), "serial", NULL)) {
278         qdev_prop_set_string(dev, "serial", serial);
279     }
280     qdev_prop_set_drive_err(dev, "drive", blk, &err);
281     if (err) {
282         error_propagate(errp, err);
283         object_unparent(OBJECT(dev));
284         return NULL;
285     }
286     object_property_set_bool(OBJECT(dev), share_rw, "share-rw", &err);
287     if (err != NULL) {
288         error_propagate(errp, err);
289         object_unparent(OBJECT(dev));
290         return NULL;
291     }
292 
293     qdev_prop_set_enum(dev, "rerror", rerror);
294     qdev_prop_set_enum(dev, "werror", werror);
295 
296     qdev_realize_and_unref(dev, &bus->qbus, &err);
297     if (err != NULL) {
298         error_propagate(errp, err);
299         object_unparent(OBJECT(dev));
300         return NULL;
301     }
302     return SCSI_DEVICE(dev);
303 }
304 
305 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
306 {
307     Location loc;
308     DriveInfo *dinfo;
309     int unit;
310 
311     loc_push_none(&loc);
312     for (unit = 0; unit <= bus->info->max_target; unit++) {
313         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
314         if (dinfo == NULL) {
315             continue;
316         }
317         qemu_opts_loc_restore(dinfo->opts);
318         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
319                                   unit, false, -1, false,
320                                   BLOCKDEV_ON_ERROR_AUTO,
321                                   BLOCKDEV_ON_ERROR_AUTO,
322                                   NULL, &error_fatal);
323     }
324     loc_pop(&loc);
325 }
326 
327 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
328 {
329     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
330     scsi_req_complete(req, CHECK_CONDITION);
331     return 0;
332 }
333 
334 static const struct SCSIReqOps reqops_invalid_field = {
335     .size         = sizeof(SCSIRequest),
336     .send_command = scsi_invalid_field
337 };
338 
339 /* SCSIReqOps implementation for invalid commands.  */
340 
341 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
342 {
343     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
344     scsi_req_complete(req, CHECK_CONDITION);
345     return 0;
346 }
347 
348 static const struct SCSIReqOps reqops_invalid_opcode = {
349     .size         = sizeof(SCSIRequest),
350     .send_command = scsi_invalid_command
351 };
352 
353 /* SCSIReqOps implementation for unit attention conditions.  */
354 
355 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
356 {
357     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
358         scsi_req_build_sense(req, req->dev->unit_attention);
359     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
360         scsi_req_build_sense(req, req->bus->unit_attention);
361     }
362     scsi_req_complete(req, CHECK_CONDITION);
363     return 0;
364 }
365 
366 static const struct SCSIReqOps reqops_unit_attention = {
367     .size         = sizeof(SCSIRequest),
368     .send_command = scsi_unit_attention
369 };
370 
371 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
372    an invalid LUN.  */
373 
374 typedef struct SCSITargetReq SCSITargetReq;
375 
376 struct SCSITargetReq {
377     SCSIRequest req;
378     int len;
379     uint8_t *buf;
380     int buf_len;
381 };
382 
383 static void store_lun(uint8_t *outbuf, int lun)
384 {
385     if (lun < 256) {
386         outbuf[1] = lun;
387         return;
388     }
389     outbuf[1] = (lun & 255);
390     outbuf[0] = (lun >> 8) | 0x40;
391 }
392 
393 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
394 {
395     BusChild *kid;
396     int i, len, n;
397     int channel, id;
398     bool found_lun0;
399 
400     if (r->req.cmd.xfer < 16) {
401         return false;
402     }
403     if (r->req.cmd.buf[2] > 2) {
404         return false;
405     }
406     channel = r->req.dev->channel;
407     id = r->req.dev->id;
408     found_lun0 = false;
409     n = 0;
410     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
411         DeviceState *qdev = kid->child;
412         SCSIDevice *dev = SCSI_DEVICE(qdev);
413 
414         if (dev->channel == channel && dev->id == id) {
415             if (dev->lun == 0) {
416                 found_lun0 = true;
417             }
418             n += 8;
419         }
420     }
421     if (!found_lun0) {
422         n += 8;
423     }
424 
425     scsi_target_alloc_buf(&r->req, n + 8);
426 
427     len = MIN(n + 8, r->req.cmd.xfer & ~7);
428     memset(r->buf, 0, len);
429     stl_be_p(&r->buf[0], n);
430     i = found_lun0 ? 8 : 16;
431     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
432         DeviceState *qdev = kid->child;
433         SCSIDevice *dev = SCSI_DEVICE(qdev);
434 
435         if (dev->channel == channel && dev->id == id) {
436             store_lun(&r->buf[i], dev->lun);
437             i += 8;
438         }
439     }
440     assert(i == n + 8);
441     r->len = len;
442     return true;
443 }
444 
445 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
446 {
447     assert(r->req.dev->lun != r->req.lun);
448 
449     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
450 
451     if (r->req.cmd.buf[1] & 0x2) {
452         /* Command support data - optional, not implemented */
453         return false;
454     }
455 
456     if (r->req.cmd.buf[1] & 0x1) {
457         /* Vital product data */
458         uint8_t page_code = r->req.cmd.buf[2];
459         r->buf[r->len++] = page_code ; /* this page */
460         r->buf[r->len++] = 0x00;
461 
462         switch (page_code) {
463         case 0x00: /* Supported page codes, mandatory */
464         {
465             int pages;
466             pages = r->len++;
467             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
468             r->buf[pages] = r->len - pages - 1; /* number of pages */
469             break;
470         }
471         default:
472             return false;
473         }
474         /* done with EVPD */
475         assert(r->len < r->buf_len);
476         r->len = MIN(r->req.cmd.xfer, r->len);
477         return true;
478     }
479 
480     /* Standard INQUIRY data */
481     if (r->req.cmd.buf[2] != 0) {
482         return false;
483     }
484 
485     /* PAGE CODE == 0 */
486     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
487     memset(r->buf, 0, r->len);
488     if (r->req.lun != 0) {
489         r->buf[0] = TYPE_NO_LUN;
490     } else {
491         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
492         r->buf[2] = 5; /* Version */
493         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
494         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
495         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
496         memcpy(&r->buf[8], "QEMU    ", 8);
497         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
498         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
499     }
500     return true;
501 }
502 
503 static size_t scsi_sense_len(SCSIRequest *req)
504 {
505     if (req->dev->type == TYPE_SCANNER)
506         return SCSI_SENSE_LEN_SCANNER;
507     else
508         return SCSI_SENSE_LEN;
509 }
510 
511 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
512 {
513     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
514     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
515 
516     if (req->lun != 0 &&
517         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
518         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
519         scsi_req_complete(req, CHECK_CONDITION);
520         return 0;
521     }
522     switch (buf[0]) {
523     case REPORT_LUNS:
524         if (!scsi_target_emulate_report_luns(r)) {
525             goto illegal_request;
526         }
527         break;
528     case INQUIRY:
529         if (!scsi_target_emulate_inquiry(r)) {
530             goto illegal_request;
531         }
532         break;
533     case REQUEST_SENSE:
534         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
535         if (req->lun != 0) {
536             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
537 
538             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
539                                           sense, fixed_sense);
540         } else {
541             r->len = scsi_device_get_sense(r->req.dev, r->buf,
542                                            MIN(req->cmd.xfer, r->buf_len),
543                                            fixed_sense);
544         }
545         if (r->req.dev->sense_is_ua) {
546             scsi_device_unit_attention_reported(req->dev);
547             r->req.dev->sense_len = 0;
548             r->req.dev->sense_is_ua = false;
549         }
550         break;
551     case TEST_UNIT_READY:
552         break;
553     default:
554         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
555         scsi_req_complete(req, CHECK_CONDITION);
556         return 0;
557     illegal_request:
558         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
559         scsi_req_complete(req, CHECK_CONDITION);
560         return 0;
561     }
562 
563     if (!r->len) {
564         scsi_req_complete(req, GOOD);
565     }
566     return r->len;
567 }
568 
569 static void scsi_target_read_data(SCSIRequest *req)
570 {
571     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
572     uint32_t n;
573 
574     n = r->len;
575     if (n > 0) {
576         r->len = 0;
577         scsi_req_data(&r->req, n);
578     } else {
579         scsi_req_complete(&r->req, GOOD);
580     }
581 }
582 
583 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
584 {
585     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
586 
587     return r->buf;
588 }
589 
590 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
591 {
592     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
593 
594     r->buf = g_malloc(len);
595     r->buf_len = len;
596 
597     return r->buf;
598 }
599 
600 static void scsi_target_free_buf(SCSIRequest *req)
601 {
602     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
603 
604     g_free(r->buf);
605 }
606 
607 static const struct SCSIReqOps reqops_target_command = {
608     .size         = sizeof(SCSITargetReq),
609     .send_command = scsi_target_send_command,
610     .read_data    = scsi_target_read_data,
611     .get_buf      = scsi_target_get_buf,
612     .free_req     = scsi_target_free_buf,
613 };
614 
615 
616 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
617                             uint32_t tag, uint32_t lun, void *hba_private)
618 {
619     SCSIRequest *req;
620     SCSIBus *bus = scsi_bus_from_device(d);
621     BusState *qbus = BUS(bus);
622     const int memset_off = offsetof(SCSIRequest, sense)
623                            + sizeof(req->sense);
624 
625     req = g_malloc(reqops->size);
626     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
627     req->refcount = 1;
628     req->bus = bus;
629     req->dev = d;
630     req->tag = tag;
631     req->lun = lun;
632     req->hba_private = hba_private;
633     req->status = -1;
634     req->ops = reqops;
635     object_ref(OBJECT(d));
636     object_ref(OBJECT(qbus->parent));
637     notifier_list_init(&req->cancel_notifiers);
638     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
639     return req;
640 }
641 
642 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
643                           uint8_t *buf, void *hba_private)
644 {
645     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
646     const SCSIReqOps *ops;
647     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
648     SCSIRequest *req;
649     SCSICommand cmd = { .len = 0 };
650     int ret;
651 
652     if ((d->unit_attention.key == UNIT_ATTENTION ||
653          bus->unit_attention.key == UNIT_ATTENTION) &&
654         (buf[0] != INQUIRY &&
655          buf[0] != REPORT_LUNS &&
656          buf[0] != GET_CONFIGURATION &&
657          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
658 
659          /*
660           * If we already have a pending unit attention condition,
661           * report this one before triggering another one.
662           */
663          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
664         ops = &reqops_unit_attention;
665     } else if (lun != d->lun ||
666                buf[0] == REPORT_LUNS ||
667                (buf[0] == REQUEST_SENSE && d->sense_len)) {
668         ops = &reqops_target_command;
669     } else {
670         ops = NULL;
671     }
672 
673     if (ops != NULL || !sc->parse_cdb) {
674         ret = scsi_req_parse_cdb(d, &cmd, buf);
675     } else {
676         ret = sc->parse_cdb(d, &cmd, buf, hba_private);
677     }
678 
679     if (ret != 0) {
680         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
681         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
682     } else {
683         assert(cmd.len != 0);
684         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
685                               cmd.mode, cmd.xfer);
686         if (cmd.lba != -1) {
687             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
688                                       cmd.lba);
689         }
690 
691         if (cmd.xfer > INT32_MAX) {
692             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
693         } else if (ops) {
694             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
695         } else {
696             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
697         }
698     }
699 
700     req->cmd = cmd;
701     req->resid = req->cmd.xfer;
702 
703     switch (buf[0]) {
704     case INQUIRY:
705         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
706         break;
707     case TEST_UNIT_READY:
708         trace_scsi_test_unit_ready(d->id, lun, tag);
709         break;
710     case REPORT_LUNS:
711         trace_scsi_report_luns(d->id, lun, tag);
712         break;
713     case REQUEST_SENSE:
714         trace_scsi_request_sense(d->id, lun, tag);
715         break;
716     default:
717         break;
718     }
719 
720     return req;
721 }
722 
723 uint8_t *scsi_req_get_buf(SCSIRequest *req)
724 {
725     return req->ops->get_buf(req);
726 }
727 
728 static void scsi_clear_unit_attention(SCSIRequest *req)
729 {
730     SCSISense *ua;
731     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
732         req->bus->unit_attention.key != UNIT_ATTENTION) {
733         return;
734     }
735 
736     /*
737      * If an INQUIRY command enters the enabled command state,
738      * the device server shall [not] clear any unit attention condition;
739      * See also MMC-6, paragraphs 6.5 and 6.6.2.
740      */
741     if (req->cmd.buf[0] == INQUIRY ||
742         req->cmd.buf[0] == GET_CONFIGURATION ||
743         req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
744         return;
745     }
746 
747     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
748         ua = &req->dev->unit_attention;
749     } else {
750         ua = &req->bus->unit_attention;
751     }
752 
753     /*
754      * If a REPORT LUNS command enters the enabled command state, [...]
755      * the device server shall clear any pending unit attention condition
756      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
757      */
758     if (req->cmd.buf[0] == REPORT_LUNS &&
759         !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
760           ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
761         return;
762     }
763 
764     *ua = SENSE_CODE(NO_SENSE);
765 }
766 
767 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
768 {
769     int ret;
770 
771     assert(len >= 14);
772     if (!req->sense_len) {
773         return 0;
774     }
775 
776     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
777 
778     /*
779      * FIXME: clearing unit attention conditions upon autosense should be done
780      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
781      * (SAM-5, 5.14).
782      *
783      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
784      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
785      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
786      */
787     if (req->dev->sense_is_ua) {
788         scsi_device_unit_attention_reported(req->dev);
789         req->dev->sense_len = 0;
790         req->dev->sense_is_ua = false;
791     }
792     return ret;
793 }
794 
795 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
796 {
797     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
798 }
799 
800 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
801 {
802     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
803                                sense.key, sense.asc, sense.ascq);
804     req->sense_len = scsi_build_sense(req->sense, sense);
805 }
806 
807 static void scsi_req_enqueue_internal(SCSIRequest *req)
808 {
809     assert(!req->enqueued);
810     scsi_req_ref(req);
811     if (req->bus->info->get_sg_list) {
812         req->sg = req->bus->info->get_sg_list(req);
813     } else {
814         req->sg = NULL;
815     }
816     req->enqueued = true;
817     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
818 }
819 
820 int32_t scsi_req_enqueue(SCSIRequest *req)
821 {
822     int32_t rc;
823 
824     assert(!req->retry);
825     scsi_req_enqueue_internal(req);
826     scsi_req_ref(req);
827     rc = req->ops->send_command(req, req->cmd.buf);
828     scsi_req_unref(req);
829     return rc;
830 }
831 
832 static void scsi_req_dequeue(SCSIRequest *req)
833 {
834     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
835     req->retry = false;
836     if (req->enqueued) {
837         QTAILQ_REMOVE(&req->dev->requests, req, next);
838         req->enqueued = false;
839         scsi_req_unref(req);
840     }
841 }
842 
843 static int scsi_get_performance_length(int num_desc, int type, int data_type)
844 {
845     /* MMC-6, paragraph 6.7.  */
846     switch (type) {
847     case 0:
848         if ((data_type & 3) == 0) {
849             /* Each descriptor is as in Table 295 - Nominal performance.  */
850             return 16 * num_desc + 8;
851         } else {
852             /* Each descriptor is as in Table 296 - Exceptions.  */
853             return 6 * num_desc + 8;
854         }
855     case 1:
856     case 4:
857     case 5:
858         return 8 * num_desc + 8;
859     case 2:
860         return 2048 * num_desc + 8;
861     case 3:
862         return 16 * num_desc + 8;
863     default:
864         return 8;
865     }
866 }
867 
868 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
869 {
870     int byte_block = (buf[2] >> 2) & 0x1;
871     int type = (buf[2] >> 4) & 0x1;
872     int xfer_unit;
873 
874     if (byte_block) {
875         if (type) {
876             xfer_unit = dev->blocksize;
877         } else {
878             xfer_unit = 512;
879         }
880     } else {
881         xfer_unit = 1;
882     }
883 
884     return xfer_unit;
885 }
886 
887 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
888 {
889     int length = buf[2] & 0x3;
890     int xfer;
891     int unit = ata_passthrough_xfer_unit(dev, buf);
892 
893     switch (length) {
894     case 0:
895     case 3: /* USB-specific.  */
896     default:
897         xfer = 0;
898         break;
899     case 1:
900         xfer = buf[3];
901         break;
902     case 2:
903         xfer = buf[4];
904         break;
905     }
906 
907     return xfer * unit;
908 }
909 
910 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
911 {
912     int extend = buf[1] & 0x1;
913     int length = buf[2] & 0x3;
914     int xfer;
915     int unit = ata_passthrough_xfer_unit(dev, buf);
916 
917     switch (length) {
918     case 0:
919     case 3: /* USB-specific.  */
920     default:
921         xfer = 0;
922         break;
923     case 1:
924         xfer = buf[4];
925         xfer |= (extend ? buf[3] << 8 : 0);
926         break;
927     case 2:
928         xfer = buf[6];
929         xfer |= (extend ? buf[5] << 8 : 0);
930         break;
931     }
932 
933     return xfer * unit;
934 }
935 
936 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
937 {
938     cmd->xfer = scsi_cdb_xfer(buf);
939     switch (buf[0]) {
940     case TEST_UNIT_READY:
941     case REWIND:
942     case START_STOP:
943     case SET_CAPACITY:
944     case WRITE_FILEMARKS:
945     case WRITE_FILEMARKS_16:
946     case SPACE:
947     case RESERVE:
948     case RELEASE:
949     case ERASE:
950     case ALLOW_MEDIUM_REMOVAL:
951     case SEEK_10:
952     case SYNCHRONIZE_CACHE:
953     case SYNCHRONIZE_CACHE_16:
954     case LOCATE_16:
955     case LOCK_UNLOCK_CACHE:
956     case SET_CD_SPEED:
957     case SET_LIMITS:
958     case WRITE_LONG_10:
959     case UPDATE_BLOCK:
960     case RESERVE_TRACK:
961     case SET_READ_AHEAD:
962     case PRE_FETCH:
963     case PRE_FETCH_16:
964     case ALLOW_OVERWRITE:
965         cmd->xfer = 0;
966         break;
967     case VERIFY_10:
968     case VERIFY_12:
969     case VERIFY_16:
970         if ((buf[1] & 2) == 0) {
971             cmd->xfer = 0;
972         } else if ((buf[1] & 4) != 0) {
973             cmd->xfer = 1;
974         }
975         cmd->xfer *= dev->blocksize;
976         break;
977     case MODE_SENSE:
978         break;
979     case WRITE_SAME_10:
980     case WRITE_SAME_16:
981         cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
982         break;
983     case READ_CAPACITY_10:
984         cmd->xfer = 8;
985         break;
986     case READ_BLOCK_LIMITS:
987         cmd->xfer = 6;
988         break;
989     case SEND_VOLUME_TAG:
990         /* GPCMD_SET_STREAMING from multimedia commands.  */
991         if (dev->type == TYPE_ROM) {
992             cmd->xfer = buf[10] | (buf[9] << 8);
993         } else {
994             cmd->xfer = buf[9] | (buf[8] << 8);
995         }
996         break;
997     case WRITE_6:
998         /* length 0 means 256 blocks */
999         if (cmd->xfer == 0) {
1000             cmd->xfer = 256;
1001         }
1002         /* fall through */
1003     case WRITE_10:
1004     case WRITE_VERIFY_10:
1005     case WRITE_12:
1006     case WRITE_VERIFY_12:
1007     case WRITE_16:
1008     case WRITE_VERIFY_16:
1009         cmd->xfer *= dev->blocksize;
1010         break;
1011     case READ_6:
1012     case READ_REVERSE:
1013         /* length 0 means 256 blocks */
1014         if (cmd->xfer == 0) {
1015             cmd->xfer = 256;
1016         }
1017         /* fall through */
1018     case READ_10:
1019     case READ_12:
1020     case READ_16:
1021         cmd->xfer *= dev->blocksize;
1022         break;
1023     case FORMAT_UNIT:
1024         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1025          * for block devices are restricted to the header right now.  */
1026         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1027             cmd->xfer = 12;
1028         } else {
1029             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1030         }
1031         break;
1032     case INQUIRY:
1033     case RECEIVE_DIAGNOSTIC:
1034     case SEND_DIAGNOSTIC:
1035         cmd->xfer = buf[4] | (buf[3] << 8);
1036         break;
1037     case READ_CD:
1038     case READ_BUFFER:
1039     case WRITE_BUFFER:
1040     case SEND_CUE_SHEET:
1041         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1042         break;
1043     case PERSISTENT_RESERVE_OUT:
1044         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1045         break;
1046     case ERASE_12:
1047         if (dev->type == TYPE_ROM) {
1048             /* MMC command GET PERFORMANCE.  */
1049             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1050                                                     buf[10], buf[1] & 0x1f);
1051         }
1052         break;
1053     case MECHANISM_STATUS:
1054     case READ_DVD_STRUCTURE:
1055     case SEND_DVD_STRUCTURE:
1056     case MAINTENANCE_OUT:
1057     case MAINTENANCE_IN:
1058         if (dev->type == TYPE_ROM) {
1059             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1060             cmd->xfer = buf[9] | (buf[8] << 8);
1061         }
1062         break;
1063     case ATA_PASSTHROUGH_12:
1064         if (dev->type == TYPE_ROM) {
1065             /* BLANK command of MMC */
1066             cmd->xfer = 0;
1067         } else {
1068             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1069         }
1070         break;
1071     case ATA_PASSTHROUGH_16:
1072         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1073         break;
1074     }
1075     return 0;
1076 }
1077 
1078 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1079 {
1080     switch (buf[0]) {
1081     /* stream commands */
1082     case ERASE_12:
1083     case ERASE_16:
1084         cmd->xfer = 0;
1085         break;
1086     case READ_6:
1087     case READ_REVERSE:
1088     case RECOVER_BUFFERED_DATA:
1089     case WRITE_6:
1090         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1091         if (buf[1] & 0x01) { /* fixed */
1092             cmd->xfer *= dev->blocksize;
1093         }
1094         break;
1095     case READ_16:
1096     case READ_REVERSE_16:
1097     case VERIFY_16:
1098     case WRITE_16:
1099         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1100         if (buf[1] & 0x01) { /* fixed */
1101             cmd->xfer *= dev->blocksize;
1102         }
1103         break;
1104     case REWIND:
1105     case LOAD_UNLOAD:
1106         cmd->xfer = 0;
1107         break;
1108     case SPACE_16:
1109         cmd->xfer = buf[13] | (buf[12] << 8);
1110         break;
1111     case READ_POSITION:
1112         switch (buf[1] & 0x1f) /* operation code */ {
1113         case SHORT_FORM_BLOCK_ID:
1114         case SHORT_FORM_VENDOR_SPECIFIC:
1115             cmd->xfer = 20;
1116             break;
1117         case LONG_FORM:
1118             cmd->xfer = 32;
1119             break;
1120         case EXTENDED_FORM:
1121             cmd->xfer = buf[8] | (buf[7] << 8);
1122             break;
1123         default:
1124             return -1;
1125         }
1126 
1127         break;
1128     case FORMAT_UNIT:
1129         cmd->xfer = buf[4] | (buf[3] << 8);
1130         break;
1131     /* generic commands */
1132     default:
1133         return scsi_req_xfer(cmd, dev, buf);
1134     }
1135     return 0;
1136 }
1137 
1138 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1139 {
1140     switch (buf[0]) {
1141     /* medium changer commands */
1142     case EXCHANGE_MEDIUM:
1143     case INITIALIZE_ELEMENT_STATUS:
1144     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1145     case MOVE_MEDIUM:
1146     case POSITION_TO_ELEMENT:
1147         cmd->xfer = 0;
1148         break;
1149     case READ_ELEMENT_STATUS:
1150         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1151         break;
1152 
1153     /* generic commands */
1154     default:
1155         return scsi_req_xfer(cmd, dev, buf);
1156     }
1157     return 0;
1158 }
1159 
1160 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1161 {
1162     switch (buf[0]) {
1163     /* Scanner commands */
1164     case OBJECT_POSITION:
1165         cmd->xfer = 0;
1166         break;
1167     case SCAN:
1168         cmd->xfer = buf[4];
1169         break;
1170     case READ_10:
1171     case SEND:
1172     case GET_WINDOW:
1173     case SET_WINDOW:
1174         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1175         break;
1176     default:
1177         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1178         return scsi_req_xfer(cmd, dev, buf);
1179     }
1180 
1181     return 0;
1182 }
1183 
1184 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1185 {
1186     if (!cmd->xfer) {
1187         cmd->mode = SCSI_XFER_NONE;
1188         return;
1189     }
1190     switch (cmd->buf[0]) {
1191     case WRITE_6:
1192     case WRITE_10:
1193     case WRITE_VERIFY_10:
1194     case WRITE_12:
1195     case WRITE_VERIFY_12:
1196     case WRITE_16:
1197     case WRITE_VERIFY_16:
1198     case VERIFY_10:
1199     case VERIFY_12:
1200     case VERIFY_16:
1201     case COPY:
1202     case COPY_VERIFY:
1203     case COMPARE:
1204     case CHANGE_DEFINITION:
1205     case LOG_SELECT:
1206     case MODE_SELECT:
1207     case MODE_SELECT_10:
1208     case SEND_DIAGNOSTIC:
1209     case WRITE_BUFFER:
1210     case FORMAT_UNIT:
1211     case REASSIGN_BLOCKS:
1212     case SEARCH_EQUAL:
1213     case SEARCH_HIGH:
1214     case SEARCH_LOW:
1215     case UPDATE_BLOCK:
1216     case WRITE_LONG_10:
1217     case WRITE_SAME_10:
1218     case WRITE_SAME_16:
1219     case UNMAP:
1220     case SEARCH_HIGH_12:
1221     case SEARCH_EQUAL_12:
1222     case SEARCH_LOW_12:
1223     case MEDIUM_SCAN:
1224     case SEND_VOLUME_TAG:
1225     case SEND_CUE_SHEET:
1226     case SEND_DVD_STRUCTURE:
1227     case PERSISTENT_RESERVE_OUT:
1228     case MAINTENANCE_OUT:
1229     case SET_WINDOW:
1230     case SCAN:
1231         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1232          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1233          */
1234         cmd->mode = SCSI_XFER_TO_DEV;
1235         break;
1236     case ATA_PASSTHROUGH_12:
1237     case ATA_PASSTHROUGH_16:
1238         /* T_DIR */
1239         cmd->mode = (cmd->buf[2] & 0x8) ?
1240                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1241         break;
1242     default:
1243         cmd->mode = SCSI_XFER_FROM_DEV;
1244         break;
1245     }
1246 }
1247 
1248 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf)
1249 {
1250     int rc;
1251     int len;
1252 
1253     cmd->lba = -1;
1254     len = scsi_cdb_length(buf);
1255     if (len < 0) {
1256         return -1;
1257     }
1258 
1259     cmd->len = len;
1260     switch (dev->type) {
1261     case TYPE_TAPE:
1262         rc = scsi_req_stream_xfer(cmd, dev, buf);
1263         break;
1264     case TYPE_MEDIUM_CHANGER:
1265         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1266         break;
1267     case TYPE_SCANNER:
1268         rc = scsi_req_scanner_length(cmd, dev, buf);
1269         break;
1270     default:
1271         rc = scsi_req_xfer(cmd, dev, buf);
1272         break;
1273     }
1274 
1275     if (rc != 0)
1276         return rc;
1277 
1278     memcpy(cmd->buf, buf, cmd->len);
1279     scsi_cmd_xfer_mode(cmd);
1280     cmd->lba = scsi_cmd_lba(cmd);
1281     return 0;
1282 }
1283 
1284 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1285 {
1286     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1287 
1288     scsi_device_set_ua(dev, sense);
1289     if (bus->info->change) {
1290         bus->info->change(bus, dev, sense);
1291     }
1292 }
1293 
1294 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1295 {
1296     assert(req->refcount > 0);
1297     req->refcount++;
1298     return req;
1299 }
1300 
1301 void scsi_req_unref(SCSIRequest *req)
1302 {
1303     assert(req->refcount > 0);
1304     if (--req->refcount == 0) {
1305         BusState *qbus = req->dev->qdev.parent_bus;
1306         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1307 
1308         if (bus->info->free_request && req->hba_private) {
1309             bus->info->free_request(bus, req->hba_private);
1310         }
1311         if (req->ops->free_req) {
1312             req->ops->free_req(req);
1313         }
1314         object_unref(OBJECT(req->dev));
1315         object_unref(OBJECT(qbus->parent));
1316         g_free(req);
1317     }
1318 }
1319 
1320 /* Tell the device that we finished processing this chunk of I/O.  It
1321    will start the next chunk or complete the command.  */
1322 void scsi_req_continue(SCSIRequest *req)
1323 {
1324     if (req->io_canceled) {
1325         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1326         return;
1327     }
1328     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1329     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1330         req->ops->write_data(req);
1331     } else {
1332         req->ops->read_data(req);
1333     }
1334 }
1335 
1336 /* Called by the devices when data is ready for the HBA.  The HBA should
1337    start a DMA operation to read or fill the device's data buffer.
1338    Once it completes, calling scsi_req_continue will restart I/O.  */
1339 void scsi_req_data(SCSIRequest *req, int len)
1340 {
1341     uint8_t *buf;
1342     if (req->io_canceled) {
1343         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1344         return;
1345     }
1346     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1347     assert(req->cmd.mode != SCSI_XFER_NONE);
1348     if (!req->sg) {
1349         req->resid -= len;
1350         req->bus->info->transfer_data(req, len);
1351         return;
1352     }
1353 
1354     /* If the device calls scsi_req_data and the HBA specified a
1355      * scatter/gather list, the transfer has to happen in a single
1356      * step.  */
1357     assert(!req->dma_started);
1358     req->dma_started = true;
1359 
1360     buf = scsi_req_get_buf(req);
1361     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1362         req->resid = dma_buf_read(buf, len, req->sg);
1363     } else {
1364         req->resid = dma_buf_write(buf, len, req->sg);
1365     }
1366     scsi_req_continue(req);
1367 }
1368 
1369 void scsi_req_print(SCSIRequest *req)
1370 {
1371     FILE *fp = stderr;
1372     int i;
1373 
1374     fprintf(fp, "[%s id=%d] %s",
1375             req->dev->qdev.parent_bus->name,
1376             req->dev->id,
1377             scsi_command_name(req->cmd.buf[0]));
1378     for (i = 1; i < req->cmd.len; i++) {
1379         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1380     }
1381     switch (req->cmd.mode) {
1382     case SCSI_XFER_NONE:
1383         fprintf(fp, " - none\n");
1384         break;
1385     case SCSI_XFER_FROM_DEV:
1386         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1387         break;
1388     case SCSI_XFER_TO_DEV:
1389         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1390         break;
1391     default:
1392         fprintf(fp, " - Oops\n");
1393         break;
1394     }
1395 }
1396 
1397 void scsi_req_complete(SCSIRequest *req, int status)
1398 {
1399     assert(req->status == -1);
1400     req->status = status;
1401 
1402     assert(req->sense_len <= sizeof(req->sense));
1403     if (status == GOOD) {
1404         req->sense_len = 0;
1405     }
1406 
1407     if (req->sense_len) {
1408         memcpy(req->dev->sense, req->sense, req->sense_len);
1409         req->dev->sense_len = req->sense_len;
1410         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1411     } else {
1412         req->dev->sense_len = 0;
1413         req->dev->sense_is_ua = false;
1414     }
1415 
1416     /*
1417      * Unit attention state is now stored in the device's sense buffer
1418      * if the HBA didn't do autosense.  Clear the pending unit attention
1419      * flags.
1420      */
1421     scsi_clear_unit_attention(req);
1422 
1423     scsi_req_ref(req);
1424     scsi_req_dequeue(req);
1425     req->bus->info->complete(req, req->status, req->resid);
1426 
1427     /* Cancelled requests might end up being completed instead of cancelled */
1428     notifier_list_notify(&req->cancel_notifiers, req);
1429     scsi_req_unref(req);
1430 }
1431 
1432 /* Called by the devices when the request is canceled. */
1433 void scsi_req_cancel_complete(SCSIRequest *req)
1434 {
1435     assert(req->io_canceled);
1436     if (req->bus->info->cancel) {
1437         req->bus->info->cancel(req);
1438     }
1439     notifier_list_notify(&req->cancel_notifiers, req);
1440     scsi_req_unref(req);
1441 }
1442 
1443 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1444  * notifier list, the bus will be notified the requests cancellation is
1445  * completed.
1446  * */
1447 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1448 {
1449     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1450     if (notifier) {
1451         notifier_list_add(&req->cancel_notifiers, notifier);
1452     }
1453     if (req->io_canceled) {
1454         /* A blk_aio_cancel_async is pending; when it finishes,
1455          * scsi_req_cancel_complete will be called and will
1456          * call the notifier we just added.  Just wait for that.
1457          */
1458         assert(req->aiocb);
1459         return;
1460     }
1461     /* Dropped in scsi_req_cancel_complete.  */
1462     scsi_req_ref(req);
1463     scsi_req_dequeue(req);
1464     req->io_canceled = true;
1465     if (req->aiocb) {
1466         blk_aio_cancel_async(req->aiocb);
1467     } else {
1468         scsi_req_cancel_complete(req);
1469     }
1470 }
1471 
1472 void scsi_req_cancel(SCSIRequest *req)
1473 {
1474     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1475     if (!req->enqueued) {
1476         return;
1477     }
1478     assert(!req->io_canceled);
1479     /* Dropped in scsi_req_cancel_complete.  */
1480     scsi_req_ref(req);
1481     scsi_req_dequeue(req);
1482     req->io_canceled = true;
1483     if (req->aiocb) {
1484         blk_aio_cancel(req->aiocb);
1485     } else {
1486         scsi_req_cancel_complete(req);
1487     }
1488 }
1489 
1490 static int scsi_ua_precedence(SCSISense sense)
1491 {
1492     if (sense.key != UNIT_ATTENTION) {
1493         return INT_MAX;
1494     }
1495     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1496         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1497         return 1;
1498     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1499         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1500         return 2;
1501     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1502         /* These two go with "all others". */
1503         ;
1504     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1505         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1506          * POWER ON OCCURRED = 1
1507          * SCSI BUS RESET OCCURRED = 2
1508          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1509          * I_T NEXUS LOSS OCCURRED = 7
1510          */
1511         return sense.ascq;
1512     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1513         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1514         return 8;
1515     }
1516     return (sense.asc << 8) | sense.ascq;
1517 }
1518 
1519 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1520 {
1521     int prec1, prec2;
1522     if (sense.key != UNIT_ATTENTION) {
1523         return;
1524     }
1525     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1526                              sense.asc, sense.ascq);
1527 
1528     /*
1529      * Override a pre-existing unit attention condition, except for a more
1530      * important reset condition.
1531     */
1532     prec1 = scsi_ua_precedence(sdev->unit_attention);
1533     prec2 = scsi_ua_precedence(sense);
1534     if (prec2 < prec1) {
1535         sdev->unit_attention = sense;
1536     }
1537 }
1538 
1539 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1540 {
1541     SCSIRequest *req;
1542 
1543     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1544     while (!QTAILQ_EMPTY(&sdev->requests)) {
1545         req = QTAILQ_FIRST(&sdev->requests);
1546         scsi_req_cancel_async(req, NULL);
1547     }
1548     blk_drain(sdev->conf.blk);
1549     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1550     scsi_device_set_ua(sdev, sense);
1551 }
1552 
1553 static char *scsibus_get_dev_path(DeviceState *dev)
1554 {
1555     SCSIDevice *d = SCSI_DEVICE(dev);
1556     DeviceState *hba = dev->parent_bus->parent;
1557     char *id;
1558     char *path;
1559 
1560     id = qdev_get_dev_path(hba);
1561     if (id) {
1562         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1563     } else {
1564         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1565     }
1566     g_free(id);
1567     return path;
1568 }
1569 
1570 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1571 {
1572     SCSIDevice *d = SCSI_DEVICE(dev);
1573     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1574                            qdev_fw_name(dev), d->id, d->lun);
1575 }
1576 
1577 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
1578 {
1579     BusChild *kid;
1580     SCSIDevice *target_dev = NULL;
1581 
1582     QTAILQ_FOREACH_REVERSE(kid, &bus->qbus.children, sibling) {
1583         DeviceState *qdev = kid->child;
1584         SCSIDevice *dev = SCSI_DEVICE(qdev);
1585 
1586         if (dev->channel == channel && dev->id == id) {
1587             if (dev->lun == lun) {
1588                 return dev;
1589             }
1590             target_dev = dev;
1591         }
1592     }
1593     return target_dev;
1594 }
1595 
1596 /* SCSI request list.  For simplicity, pv points to the whole device */
1597 
1598 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1599                              const VMStateField *field, QJSON *vmdesc)
1600 {
1601     SCSIDevice *s = pv;
1602     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1603     SCSIRequest *req;
1604 
1605     QTAILQ_FOREACH(req, &s->requests, next) {
1606         assert(!req->io_canceled);
1607         assert(req->status == -1);
1608         assert(req->enqueued);
1609 
1610         qemu_put_sbyte(f, req->retry ? 1 : 2);
1611         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1612         qemu_put_be32s(f, &req->tag);
1613         qemu_put_be32s(f, &req->lun);
1614         if (bus->info->save_request) {
1615             bus->info->save_request(f, req);
1616         }
1617         if (req->ops->save_request) {
1618             req->ops->save_request(f, req);
1619         }
1620     }
1621     qemu_put_sbyte(f, 0);
1622 
1623     return 0;
1624 }
1625 
1626 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1627                              const VMStateField *field)
1628 {
1629     SCSIDevice *s = pv;
1630     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1631     int8_t sbyte;
1632 
1633     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1634         uint8_t buf[SCSI_CMD_BUF_SIZE];
1635         uint32_t tag;
1636         uint32_t lun;
1637         SCSIRequest *req;
1638 
1639         qemu_get_buffer(f, buf, sizeof(buf));
1640         qemu_get_be32s(f, &tag);
1641         qemu_get_be32s(f, &lun);
1642         req = scsi_req_new(s, tag, lun, buf, NULL);
1643         req->retry = (sbyte == 1);
1644         if (bus->info->load_request) {
1645             req->hba_private = bus->info->load_request(f, req);
1646         }
1647         if (req->ops->load_request) {
1648             req->ops->load_request(f, req);
1649         }
1650 
1651         /* Just restart it later.  */
1652         scsi_req_enqueue_internal(req);
1653 
1654         /* At this point, the request will be kept alive by the reference
1655          * added by scsi_req_enqueue_internal, so we can release our reference.
1656          * The HBA of course will add its own reference in the load_request
1657          * callback if it needs to hold on the SCSIRequest.
1658          */
1659         scsi_req_unref(req);
1660     }
1661 
1662     return 0;
1663 }
1664 
1665 static const VMStateInfo vmstate_info_scsi_requests = {
1666     .name = "scsi-requests",
1667     .get  = get_scsi_requests,
1668     .put  = put_scsi_requests,
1669 };
1670 
1671 static bool scsi_sense_state_needed(void *opaque)
1672 {
1673     SCSIDevice *s = opaque;
1674 
1675     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1676 }
1677 
1678 static const VMStateDescription vmstate_scsi_sense_state = {
1679     .name = "SCSIDevice/sense",
1680     .version_id = 1,
1681     .minimum_version_id = 1,
1682     .needed = scsi_sense_state_needed,
1683     .fields = (VMStateField[]) {
1684         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1685                                 SCSI_SENSE_BUF_SIZE_OLD,
1686                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1687         VMSTATE_END_OF_LIST()
1688     }
1689 };
1690 
1691 const VMStateDescription vmstate_scsi_device = {
1692     .name = "SCSIDevice",
1693     .version_id = 1,
1694     .minimum_version_id = 1,
1695     .fields = (VMStateField[]) {
1696         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1697         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1698         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1699         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1700         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1701         VMSTATE_UINT32(sense_len, SCSIDevice),
1702         {
1703             .name         = "requests",
1704             .version_id   = 0,
1705             .field_exists = NULL,
1706             .size         = 0,   /* ouch */
1707             .info         = &vmstate_info_scsi_requests,
1708             .flags        = VMS_SINGLE,
1709             .offset       = 0,
1710         },
1711         VMSTATE_END_OF_LIST()
1712     },
1713     .subsections = (const VMStateDescription*[]) {
1714         &vmstate_scsi_sense_state,
1715         NULL
1716     }
1717 };
1718 
1719 static void scsi_device_class_init(ObjectClass *klass, void *data)
1720 {
1721     DeviceClass *k = DEVICE_CLASS(klass);
1722     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1723     k->bus_type  = TYPE_SCSI_BUS;
1724     k->realize   = scsi_qdev_realize;
1725     k->unrealize = scsi_qdev_unrealize;
1726     device_class_set_props(k, scsi_props);
1727 }
1728 
1729 static void scsi_dev_instance_init(Object *obj)
1730 {
1731     DeviceState *dev = DEVICE(obj);
1732     SCSIDevice *s = SCSI_DEVICE(dev);
1733 
1734     device_add_bootindex_property(obj, &s->conf.bootindex,
1735                                   "bootindex", NULL,
1736                                   &s->qdev);
1737 }
1738 
1739 static const TypeInfo scsi_device_type_info = {
1740     .name = TYPE_SCSI_DEVICE,
1741     .parent = TYPE_DEVICE,
1742     .instance_size = sizeof(SCSIDevice),
1743     .abstract = true,
1744     .class_size = sizeof(SCSIDeviceClass),
1745     .class_init = scsi_device_class_init,
1746     .instance_init = scsi_dev_instance_init,
1747 };
1748 
1749 static void scsi_register_types(void)
1750 {
1751     type_register_static(&scsi_bus_info);
1752     type_register_static(&scsi_device_type_info);
1753 }
1754 
1755 type_init(scsi_register_types)
1756