xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision da054c64)
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                                       BlockdevOnError rerror,
230                                       BlockdevOnError werror,
231                                       const char *serial, Error **errp)
232 {
233     const char *driver;
234     char *name;
235     DeviceState *dev;
236     Error *err = NULL;
237 
238     driver = blk_is_sg(blk) ? "scsi-generic" : "scsi-disk";
239     dev = qdev_create(&bus->qbus, driver);
240     name = g_strdup_printf("legacy[%d]", unit);
241     object_property_add_child(OBJECT(bus), name, OBJECT(dev), NULL);
242     g_free(name);
243 
244     qdev_prop_set_uint32(dev, "scsi-id", unit);
245     if (bootindex >= 0) {
246         object_property_set_int(OBJECT(dev), bootindex, "bootindex",
247                                 &error_abort);
248     }
249     if (object_property_find(OBJECT(dev), "removable", NULL)) {
250         qdev_prop_set_bit(dev, "removable", removable);
251     }
252     if (serial && object_property_find(OBJECT(dev), "serial", NULL)) {
253         qdev_prop_set_string(dev, "serial", serial);
254     }
255     qdev_prop_set_drive(dev, "drive", blk, &err);
256     if (err) {
257         error_propagate(errp, err);
258         object_unparent(OBJECT(dev));
259         return NULL;
260     }
261     object_property_set_bool(OBJECT(dev), share_rw, "share-rw", &err);
262     if (err != NULL) {
263         error_propagate(errp, err);
264         object_unparent(OBJECT(dev));
265         return NULL;
266     }
267 
268     qdev_prop_set_enum(dev, "rerror", rerror);
269     qdev_prop_set_enum(dev, "werror", werror);
270 
271     object_property_set_bool(OBJECT(dev), true, "realized", &err);
272     if (err != NULL) {
273         error_propagate(errp, err);
274         object_unparent(OBJECT(dev));
275         return NULL;
276     }
277     return SCSI_DEVICE(dev);
278 }
279 
280 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
281 {
282     Location loc;
283     DriveInfo *dinfo;
284     int unit;
285 
286     loc_push_none(&loc);
287     for (unit = 0; unit <= bus->info->max_target; unit++) {
288         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
289         if (dinfo == NULL) {
290             continue;
291         }
292         qemu_opts_loc_restore(dinfo->opts);
293         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
294                                   unit, false, -1, false,
295                                   BLOCKDEV_ON_ERROR_AUTO,
296                                   BLOCKDEV_ON_ERROR_AUTO,
297                                   NULL, &error_fatal);
298     }
299     loc_pop(&loc);
300 }
301 
302 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
303 {
304     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
305     scsi_req_complete(req, CHECK_CONDITION);
306     return 0;
307 }
308 
309 static const struct SCSIReqOps reqops_invalid_field = {
310     .size         = sizeof(SCSIRequest),
311     .send_command = scsi_invalid_field
312 };
313 
314 /* SCSIReqOps implementation for invalid commands.  */
315 
316 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
317 {
318     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
319     scsi_req_complete(req, CHECK_CONDITION);
320     return 0;
321 }
322 
323 static const struct SCSIReqOps reqops_invalid_opcode = {
324     .size         = sizeof(SCSIRequest),
325     .send_command = scsi_invalid_command
326 };
327 
328 /* SCSIReqOps implementation for unit attention conditions.  */
329 
330 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
331 {
332     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
333         scsi_req_build_sense(req, req->dev->unit_attention);
334     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
335         scsi_req_build_sense(req, req->bus->unit_attention);
336     }
337     scsi_req_complete(req, CHECK_CONDITION);
338     return 0;
339 }
340 
341 static const struct SCSIReqOps reqops_unit_attention = {
342     .size         = sizeof(SCSIRequest),
343     .send_command = scsi_unit_attention
344 };
345 
346 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
347    an invalid LUN.  */
348 
349 typedef struct SCSITargetReq SCSITargetReq;
350 
351 struct SCSITargetReq {
352     SCSIRequest req;
353     int len;
354     uint8_t *buf;
355     int buf_len;
356 };
357 
358 static void store_lun(uint8_t *outbuf, int lun)
359 {
360     if (lun < 256) {
361         outbuf[1] = lun;
362         return;
363     }
364     outbuf[1] = (lun & 255);
365     outbuf[0] = (lun >> 8) | 0x40;
366 }
367 
368 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
369 {
370     BusChild *kid;
371     int i, len, n;
372     int channel, id;
373     bool found_lun0;
374 
375     if (r->req.cmd.xfer < 16) {
376         return false;
377     }
378     if (r->req.cmd.buf[2] > 2) {
379         return false;
380     }
381     channel = r->req.dev->channel;
382     id = r->req.dev->id;
383     found_lun0 = false;
384     n = 0;
385     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
386         DeviceState *qdev = kid->child;
387         SCSIDevice *dev = SCSI_DEVICE(qdev);
388 
389         if (dev->channel == channel && dev->id == id) {
390             if (dev->lun == 0) {
391                 found_lun0 = true;
392             }
393             n += 8;
394         }
395     }
396     if (!found_lun0) {
397         n += 8;
398     }
399 
400     scsi_target_alloc_buf(&r->req, n + 8);
401 
402     len = MIN(n + 8, r->req.cmd.xfer & ~7);
403     memset(r->buf, 0, len);
404     stl_be_p(&r->buf[0], n);
405     i = found_lun0 ? 8 : 16;
406     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
407         DeviceState *qdev = kid->child;
408         SCSIDevice *dev = SCSI_DEVICE(qdev);
409 
410         if (dev->channel == channel && dev->id == id) {
411             store_lun(&r->buf[i], dev->lun);
412             i += 8;
413         }
414     }
415     assert(i == n + 8);
416     r->len = len;
417     return true;
418 }
419 
420 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
421 {
422     assert(r->req.dev->lun != r->req.lun);
423 
424     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
425 
426     if (r->req.cmd.buf[1] & 0x2) {
427         /* Command support data - optional, not implemented */
428         return false;
429     }
430 
431     if (r->req.cmd.buf[1] & 0x1) {
432         /* Vital product data */
433         uint8_t page_code = r->req.cmd.buf[2];
434         r->buf[r->len++] = page_code ; /* this page */
435         r->buf[r->len++] = 0x00;
436 
437         switch (page_code) {
438         case 0x00: /* Supported page codes, mandatory */
439         {
440             int pages;
441             pages = r->len++;
442             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
443             r->buf[pages] = r->len - pages - 1; /* number of pages */
444             break;
445         }
446         default:
447             return false;
448         }
449         /* done with EVPD */
450         assert(r->len < r->buf_len);
451         r->len = MIN(r->req.cmd.xfer, r->len);
452         return true;
453     }
454 
455     /* Standard INQUIRY data */
456     if (r->req.cmd.buf[2] != 0) {
457         return false;
458     }
459 
460     /* PAGE CODE == 0 */
461     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
462     memset(r->buf, 0, r->len);
463     if (r->req.lun != 0) {
464         r->buf[0] = TYPE_NO_LUN;
465     } else {
466         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
467         r->buf[2] = 5; /* Version */
468         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
469         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
470         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
471         memcpy(&r->buf[8], "QEMU    ", 8);
472         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
473         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
474     }
475     return true;
476 }
477 
478 static size_t scsi_sense_len(SCSIRequest *req)
479 {
480     if (req->dev->type == TYPE_SCANNER)
481         return SCSI_SENSE_LEN_SCANNER;
482     else
483         return SCSI_SENSE_LEN;
484 }
485 
486 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
487 {
488     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
489     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
490 
491     if (req->lun != 0 &&
492         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
493         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
494         scsi_req_complete(req, CHECK_CONDITION);
495         return 0;
496     }
497     switch (buf[0]) {
498     case REPORT_LUNS:
499         if (!scsi_target_emulate_report_luns(r)) {
500             goto illegal_request;
501         }
502         break;
503     case INQUIRY:
504         if (!scsi_target_emulate_inquiry(r)) {
505             goto illegal_request;
506         }
507         break;
508     case REQUEST_SENSE:
509         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
510         if (req->lun != 0) {
511             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
512 
513             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
514                                           sense, fixed_sense);
515         } else {
516             r->len = scsi_device_get_sense(r->req.dev, r->buf,
517                                            MIN(req->cmd.xfer, r->buf_len),
518                                            fixed_sense);
519         }
520         if (r->req.dev->sense_is_ua) {
521             scsi_device_unit_attention_reported(req->dev);
522             r->req.dev->sense_len = 0;
523             r->req.dev->sense_is_ua = false;
524         }
525         break;
526     case TEST_UNIT_READY:
527         break;
528     default:
529         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
530         scsi_req_complete(req, CHECK_CONDITION);
531         return 0;
532     illegal_request:
533         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
534         scsi_req_complete(req, CHECK_CONDITION);
535         return 0;
536     }
537 
538     if (!r->len) {
539         scsi_req_complete(req, GOOD);
540     }
541     return r->len;
542 }
543 
544 static void scsi_target_read_data(SCSIRequest *req)
545 {
546     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
547     uint32_t n;
548 
549     n = r->len;
550     if (n > 0) {
551         r->len = 0;
552         scsi_req_data(&r->req, n);
553     } else {
554         scsi_req_complete(&r->req, GOOD);
555     }
556 }
557 
558 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
559 {
560     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
561 
562     return r->buf;
563 }
564 
565 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
566 {
567     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
568 
569     r->buf = g_malloc(len);
570     r->buf_len = len;
571 
572     return r->buf;
573 }
574 
575 static void scsi_target_free_buf(SCSIRequest *req)
576 {
577     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
578 
579     g_free(r->buf);
580 }
581 
582 static const struct SCSIReqOps reqops_target_command = {
583     .size         = sizeof(SCSITargetReq),
584     .send_command = scsi_target_send_command,
585     .read_data    = scsi_target_read_data,
586     .get_buf      = scsi_target_get_buf,
587     .free_req     = scsi_target_free_buf,
588 };
589 
590 
591 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
592                             uint32_t tag, uint32_t lun, void *hba_private)
593 {
594     SCSIRequest *req;
595     SCSIBus *bus = scsi_bus_from_device(d);
596     BusState *qbus = BUS(bus);
597     const int memset_off = offsetof(SCSIRequest, sense)
598                            + sizeof(req->sense);
599 
600     req = g_malloc(reqops->size);
601     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
602     req->refcount = 1;
603     req->bus = bus;
604     req->dev = d;
605     req->tag = tag;
606     req->lun = lun;
607     req->hba_private = hba_private;
608     req->status = -1;
609     req->ops = reqops;
610     object_ref(OBJECT(d));
611     object_ref(OBJECT(qbus->parent));
612     notifier_list_init(&req->cancel_notifiers);
613     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
614     return req;
615 }
616 
617 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
618                           uint8_t *buf, void *hba_private)
619 {
620     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
621     const SCSIReqOps *ops;
622     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
623     SCSIRequest *req;
624     SCSICommand cmd = { .len = 0 };
625     int ret;
626 
627     if ((d->unit_attention.key == UNIT_ATTENTION ||
628          bus->unit_attention.key == UNIT_ATTENTION) &&
629         (buf[0] != INQUIRY &&
630          buf[0] != REPORT_LUNS &&
631          buf[0] != GET_CONFIGURATION &&
632          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
633 
634          /*
635           * If we already have a pending unit attention condition,
636           * report this one before triggering another one.
637           */
638          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
639         ops = &reqops_unit_attention;
640     } else if (lun != d->lun ||
641                buf[0] == REPORT_LUNS ||
642                (buf[0] == REQUEST_SENSE && d->sense_len)) {
643         ops = &reqops_target_command;
644     } else {
645         ops = NULL;
646     }
647 
648     if (ops != NULL || !sc->parse_cdb) {
649         ret = scsi_req_parse_cdb(d, &cmd, buf);
650     } else {
651         ret = sc->parse_cdb(d, &cmd, buf, hba_private);
652     }
653 
654     if (ret != 0) {
655         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
656         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
657     } else {
658         assert(cmd.len != 0);
659         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
660                               cmd.mode, cmd.xfer);
661         if (cmd.lba != -1) {
662             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
663                                       cmd.lba);
664         }
665 
666         if (cmd.xfer > INT32_MAX) {
667             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
668         } else if (ops) {
669             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
670         } else {
671             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
672         }
673     }
674 
675     req->cmd = cmd;
676     req->resid = req->cmd.xfer;
677 
678     switch (buf[0]) {
679     case INQUIRY:
680         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
681         break;
682     case TEST_UNIT_READY:
683         trace_scsi_test_unit_ready(d->id, lun, tag);
684         break;
685     case REPORT_LUNS:
686         trace_scsi_report_luns(d->id, lun, tag);
687         break;
688     case REQUEST_SENSE:
689         trace_scsi_request_sense(d->id, lun, tag);
690         break;
691     default:
692         break;
693     }
694 
695     return req;
696 }
697 
698 uint8_t *scsi_req_get_buf(SCSIRequest *req)
699 {
700     return req->ops->get_buf(req);
701 }
702 
703 static void scsi_clear_unit_attention(SCSIRequest *req)
704 {
705     SCSISense *ua;
706     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
707         req->bus->unit_attention.key != UNIT_ATTENTION) {
708         return;
709     }
710 
711     /*
712      * If an INQUIRY command enters the enabled command state,
713      * the device server shall [not] clear any unit attention condition;
714      * See also MMC-6, paragraphs 6.5 and 6.6.2.
715      */
716     if (req->cmd.buf[0] == INQUIRY ||
717         req->cmd.buf[0] == GET_CONFIGURATION ||
718         req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
719         return;
720     }
721 
722     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
723         ua = &req->dev->unit_attention;
724     } else {
725         ua = &req->bus->unit_attention;
726     }
727 
728     /*
729      * If a REPORT LUNS command enters the enabled command state, [...]
730      * the device server shall clear any pending unit attention condition
731      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
732      */
733     if (req->cmd.buf[0] == REPORT_LUNS &&
734         !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
735           ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
736         return;
737     }
738 
739     *ua = SENSE_CODE(NO_SENSE);
740 }
741 
742 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
743 {
744     int ret;
745 
746     assert(len >= 14);
747     if (!req->sense_len) {
748         return 0;
749     }
750 
751     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
752 
753     /*
754      * FIXME: clearing unit attention conditions upon autosense should be done
755      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
756      * (SAM-5, 5.14).
757      *
758      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
759      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
760      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
761      */
762     if (req->dev->sense_is_ua) {
763         scsi_device_unit_attention_reported(req->dev);
764         req->dev->sense_len = 0;
765         req->dev->sense_is_ua = false;
766     }
767     return ret;
768 }
769 
770 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
771 {
772     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
773 }
774 
775 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
776 {
777     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
778                                sense.key, sense.asc, sense.ascq);
779     req->sense_len = scsi_build_sense(req->sense, sense);
780 }
781 
782 static void scsi_req_enqueue_internal(SCSIRequest *req)
783 {
784     assert(!req->enqueued);
785     scsi_req_ref(req);
786     if (req->bus->info->get_sg_list) {
787         req->sg = req->bus->info->get_sg_list(req);
788     } else {
789         req->sg = NULL;
790     }
791     req->enqueued = true;
792     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
793 }
794 
795 int32_t scsi_req_enqueue(SCSIRequest *req)
796 {
797     int32_t rc;
798 
799     assert(!req->retry);
800     scsi_req_enqueue_internal(req);
801     scsi_req_ref(req);
802     rc = req->ops->send_command(req, req->cmd.buf);
803     scsi_req_unref(req);
804     return rc;
805 }
806 
807 static void scsi_req_dequeue(SCSIRequest *req)
808 {
809     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
810     req->retry = false;
811     if (req->enqueued) {
812         QTAILQ_REMOVE(&req->dev->requests, req, next);
813         req->enqueued = false;
814         scsi_req_unref(req);
815     }
816 }
817 
818 static int scsi_get_performance_length(int num_desc, int type, int data_type)
819 {
820     /* MMC-6, paragraph 6.7.  */
821     switch (type) {
822     case 0:
823         if ((data_type & 3) == 0) {
824             /* Each descriptor is as in Table 295 - Nominal performance.  */
825             return 16 * num_desc + 8;
826         } else {
827             /* Each descriptor is as in Table 296 - Exceptions.  */
828             return 6 * num_desc + 8;
829         }
830     case 1:
831     case 4:
832     case 5:
833         return 8 * num_desc + 8;
834     case 2:
835         return 2048 * num_desc + 8;
836     case 3:
837         return 16 * num_desc + 8;
838     default:
839         return 8;
840     }
841 }
842 
843 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
844 {
845     int byte_block = (buf[2] >> 2) & 0x1;
846     int type = (buf[2] >> 4) & 0x1;
847     int xfer_unit;
848 
849     if (byte_block) {
850         if (type) {
851             xfer_unit = dev->blocksize;
852         } else {
853             xfer_unit = 512;
854         }
855     } else {
856         xfer_unit = 1;
857     }
858 
859     return xfer_unit;
860 }
861 
862 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
863 {
864     int length = buf[2] & 0x3;
865     int xfer;
866     int unit = ata_passthrough_xfer_unit(dev, buf);
867 
868     switch (length) {
869     case 0:
870     case 3: /* USB-specific.  */
871     default:
872         xfer = 0;
873         break;
874     case 1:
875         xfer = buf[3];
876         break;
877     case 2:
878         xfer = buf[4];
879         break;
880     }
881 
882     return xfer * unit;
883 }
884 
885 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
886 {
887     int extend = buf[1] & 0x1;
888     int length = buf[2] & 0x3;
889     int xfer;
890     int unit = ata_passthrough_xfer_unit(dev, buf);
891 
892     switch (length) {
893     case 0:
894     case 3: /* USB-specific.  */
895     default:
896         xfer = 0;
897         break;
898     case 1:
899         xfer = buf[4];
900         xfer |= (extend ? buf[3] << 8 : 0);
901         break;
902     case 2:
903         xfer = buf[6];
904         xfer |= (extend ? buf[5] << 8 : 0);
905         break;
906     }
907 
908     return xfer * unit;
909 }
910 
911 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
912 {
913     cmd->xfer = scsi_cdb_xfer(buf);
914     switch (buf[0]) {
915     case TEST_UNIT_READY:
916     case REWIND:
917     case START_STOP:
918     case SET_CAPACITY:
919     case WRITE_FILEMARKS:
920     case WRITE_FILEMARKS_16:
921     case SPACE:
922     case RESERVE:
923     case RELEASE:
924     case ERASE:
925     case ALLOW_MEDIUM_REMOVAL:
926     case SEEK_10:
927     case SYNCHRONIZE_CACHE:
928     case SYNCHRONIZE_CACHE_16:
929     case LOCATE_16:
930     case LOCK_UNLOCK_CACHE:
931     case SET_CD_SPEED:
932     case SET_LIMITS:
933     case WRITE_LONG_10:
934     case UPDATE_BLOCK:
935     case RESERVE_TRACK:
936     case SET_READ_AHEAD:
937     case PRE_FETCH:
938     case PRE_FETCH_16:
939     case ALLOW_OVERWRITE:
940         cmd->xfer = 0;
941         break;
942     case VERIFY_10:
943     case VERIFY_12:
944     case VERIFY_16:
945         if ((buf[1] & 2) == 0) {
946             cmd->xfer = 0;
947         } else if ((buf[1] & 4) != 0) {
948             cmd->xfer = 1;
949         }
950         cmd->xfer *= dev->blocksize;
951         break;
952     case MODE_SENSE:
953         break;
954     case WRITE_SAME_10:
955     case WRITE_SAME_16:
956         cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
957         break;
958     case READ_CAPACITY_10:
959         cmd->xfer = 8;
960         break;
961     case READ_BLOCK_LIMITS:
962         cmd->xfer = 6;
963         break;
964     case SEND_VOLUME_TAG:
965         /* GPCMD_SET_STREAMING from multimedia commands.  */
966         if (dev->type == TYPE_ROM) {
967             cmd->xfer = buf[10] | (buf[9] << 8);
968         } else {
969             cmd->xfer = buf[9] | (buf[8] << 8);
970         }
971         break;
972     case WRITE_6:
973         /* length 0 means 256 blocks */
974         if (cmd->xfer == 0) {
975             cmd->xfer = 256;
976         }
977         /* fall through */
978     case WRITE_10:
979     case WRITE_VERIFY_10:
980     case WRITE_12:
981     case WRITE_VERIFY_12:
982     case WRITE_16:
983     case WRITE_VERIFY_16:
984         cmd->xfer *= dev->blocksize;
985         break;
986     case READ_6:
987     case READ_REVERSE:
988         /* length 0 means 256 blocks */
989         if (cmd->xfer == 0) {
990             cmd->xfer = 256;
991         }
992         /* fall through */
993     case READ_10:
994     case READ_12:
995     case READ_16:
996         cmd->xfer *= dev->blocksize;
997         break;
998     case FORMAT_UNIT:
999         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1000          * for block devices are restricted to the header right now.  */
1001         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1002             cmd->xfer = 12;
1003         } else {
1004             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1005         }
1006         break;
1007     case INQUIRY:
1008     case RECEIVE_DIAGNOSTIC:
1009     case SEND_DIAGNOSTIC:
1010         cmd->xfer = buf[4] | (buf[3] << 8);
1011         break;
1012     case READ_CD:
1013     case READ_BUFFER:
1014     case WRITE_BUFFER:
1015     case SEND_CUE_SHEET:
1016         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1017         break;
1018     case PERSISTENT_RESERVE_OUT:
1019         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1020         break;
1021     case ERASE_12:
1022         if (dev->type == TYPE_ROM) {
1023             /* MMC command GET PERFORMANCE.  */
1024             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1025                                                     buf[10], buf[1] & 0x1f);
1026         }
1027         break;
1028     case MECHANISM_STATUS:
1029     case READ_DVD_STRUCTURE:
1030     case SEND_DVD_STRUCTURE:
1031     case MAINTENANCE_OUT:
1032     case MAINTENANCE_IN:
1033         if (dev->type == TYPE_ROM) {
1034             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1035             cmd->xfer = buf[9] | (buf[8] << 8);
1036         }
1037         break;
1038     case ATA_PASSTHROUGH_12:
1039         if (dev->type == TYPE_ROM) {
1040             /* BLANK command of MMC */
1041             cmd->xfer = 0;
1042         } else {
1043             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1044         }
1045         break;
1046     case ATA_PASSTHROUGH_16:
1047         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1048         break;
1049     }
1050     return 0;
1051 }
1052 
1053 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1054 {
1055     switch (buf[0]) {
1056     /* stream commands */
1057     case ERASE_12:
1058     case ERASE_16:
1059         cmd->xfer = 0;
1060         break;
1061     case READ_6:
1062     case READ_REVERSE:
1063     case RECOVER_BUFFERED_DATA:
1064     case WRITE_6:
1065         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1066         if (buf[1] & 0x01) { /* fixed */
1067             cmd->xfer *= dev->blocksize;
1068         }
1069         break;
1070     case READ_16:
1071     case READ_REVERSE_16:
1072     case VERIFY_16:
1073     case WRITE_16:
1074         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1075         if (buf[1] & 0x01) { /* fixed */
1076             cmd->xfer *= dev->blocksize;
1077         }
1078         break;
1079     case REWIND:
1080     case LOAD_UNLOAD:
1081         cmd->xfer = 0;
1082         break;
1083     case SPACE_16:
1084         cmd->xfer = buf[13] | (buf[12] << 8);
1085         break;
1086     case READ_POSITION:
1087         switch (buf[1] & 0x1f) /* operation code */ {
1088         case SHORT_FORM_BLOCK_ID:
1089         case SHORT_FORM_VENDOR_SPECIFIC:
1090             cmd->xfer = 20;
1091             break;
1092         case LONG_FORM:
1093             cmd->xfer = 32;
1094             break;
1095         case EXTENDED_FORM:
1096             cmd->xfer = buf[8] | (buf[7] << 8);
1097             break;
1098         default:
1099             return -1;
1100         }
1101 
1102         break;
1103     case FORMAT_UNIT:
1104         cmd->xfer = buf[4] | (buf[3] << 8);
1105         break;
1106     /* generic commands */
1107     default:
1108         return scsi_req_xfer(cmd, dev, buf);
1109     }
1110     return 0;
1111 }
1112 
1113 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1114 {
1115     switch (buf[0]) {
1116     /* medium changer commands */
1117     case EXCHANGE_MEDIUM:
1118     case INITIALIZE_ELEMENT_STATUS:
1119     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1120     case MOVE_MEDIUM:
1121     case POSITION_TO_ELEMENT:
1122         cmd->xfer = 0;
1123         break;
1124     case READ_ELEMENT_STATUS:
1125         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1126         break;
1127 
1128     /* generic commands */
1129     default:
1130         return scsi_req_xfer(cmd, dev, buf);
1131     }
1132     return 0;
1133 }
1134 
1135 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1136 {
1137     switch (buf[0]) {
1138     /* Scanner commands */
1139     case OBJECT_POSITION:
1140         cmd->xfer = 0;
1141         break;
1142     case SCAN:
1143         cmd->xfer = buf[4];
1144         break;
1145     case READ_10:
1146     case SEND:
1147     case GET_WINDOW:
1148     case SET_WINDOW:
1149         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1150         break;
1151     default:
1152         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1153         return scsi_req_xfer(cmd, dev, buf);
1154     }
1155 
1156     return 0;
1157 }
1158 
1159 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1160 {
1161     if (!cmd->xfer) {
1162         cmd->mode = SCSI_XFER_NONE;
1163         return;
1164     }
1165     switch (cmd->buf[0]) {
1166     case WRITE_6:
1167     case WRITE_10:
1168     case WRITE_VERIFY_10:
1169     case WRITE_12:
1170     case WRITE_VERIFY_12:
1171     case WRITE_16:
1172     case WRITE_VERIFY_16:
1173     case VERIFY_10:
1174     case VERIFY_12:
1175     case VERIFY_16:
1176     case COPY:
1177     case COPY_VERIFY:
1178     case COMPARE:
1179     case CHANGE_DEFINITION:
1180     case LOG_SELECT:
1181     case MODE_SELECT:
1182     case MODE_SELECT_10:
1183     case SEND_DIAGNOSTIC:
1184     case WRITE_BUFFER:
1185     case FORMAT_UNIT:
1186     case REASSIGN_BLOCKS:
1187     case SEARCH_EQUAL:
1188     case SEARCH_HIGH:
1189     case SEARCH_LOW:
1190     case UPDATE_BLOCK:
1191     case WRITE_LONG_10:
1192     case WRITE_SAME_10:
1193     case WRITE_SAME_16:
1194     case UNMAP:
1195     case SEARCH_HIGH_12:
1196     case SEARCH_EQUAL_12:
1197     case SEARCH_LOW_12:
1198     case MEDIUM_SCAN:
1199     case SEND_VOLUME_TAG:
1200     case SEND_CUE_SHEET:
1201     case SEND_DVD_STRUCTURE:
1202     case PERSISTENT_RESERVE_OUT:
1203     case MAINTENANCE_OUT:
1204     case SET_WINDOW:
1205     case SCAN:
1206         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1207          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1208          */
1209         cmd->mode = SCSI_XFER_TO_DEV;
1210         break;
1211     case ATA_PASSTHROUGH_12:
1212     case ATA_PASSTHROUGH_16:
1213         /* T_DIR */
1214         cmd->mode = (cmd->buf[2] & 0x8) ?
1215                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1216         break;
1217     default:
1218         cmd->mode = SCSI_XFER_FROM_DEV;
1219         break;
1220     }
1221 }
1222 
1223 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf)
1224 {
1225     int rc;
1226     int len;
1227 
1228     cmd->lba = -1;
1229     len = scsi_cdb_length(buf);
1230     if (len < 0) {
1231         return -1;
1232     }
1233 
1234     cmd->len = len;
1235     switch (dev->type) {
1236     case TYPE_TAPE:
1237         rc = scsi_req_stream_xfer(cmd, dev, buf);
1238         break;
1239     case TYPE_MEDIUM_CHANGER:
1240         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1241         break;
1242     case TYPE_SCANNER:
1243         rc = scsi_req_scanner_length(cmd, dev, buf);
1244         break;
1245     default:
1246         rc = scsi_req_xfer(cmd, dev, buf);
1247         break;
1248     }
1249 
1250     if (rc != 0)
1251         return rc;
1252 
1253     memcpy(cmd->buf, buf, cmd->len);
1254     scsi_cmd_xfer_mode(cmd);
1255     cmd->lba = scsi_cmd_lba(cmd);
1256     return 0;
1257 }
1258 
1259 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1260 {
1261     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1262 
1263     scsi_device_set_ua(dev, sense);
1264     if (bus->info->change) {
1265         bus->info->change(bus, dev, sense);
1266     }
1267 }
1268 
1269 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1270 {
1271     assert(req->refcount > 0);
1272     req->refcount++;
1273     return req;
1274 }
1275 
1276 void scsi_req_unref(SCSIRequest *req)
1277 {
1278     assert(req->refcount > 0);
1279     if (--req->refcount == 0) {
1280         BusState *qbus = req->dev->qdev.parent_bus;
1281         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1282 
1283         if (bus->info->free_request && req->hba_private) {
1284             bus->info->free_request(bus, req->hba_private);
1285         }
1286         if (req->ops->free_req) {
1287             req->ops->free_req(req);
1288         }
1289         object_unref(OBJECT(req->dev));
1290         object_unref(OBJECT(qbus->parent));
1291         g_free(req);
1292     }
1293 }
1294 
1295 /* Tell the device that we finished processing this chunk of I/O.  It
1296    will start the next chunk or complete the command.  */
1297 void scsi_req_continue(SCSIRequest *req)
1298 {
1299     if (req->io_canceled) {
1300         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1301         return;
1302     }
1303     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1304     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1305         req->ops->write_data(req);
1306     } else {
1307         req->ops->read_data(req);
1308     }
1309 }
1310 
1311 /* Called by the devices when data is ready for the HBA.  The HBA should
1312    start a DMA operation to read or fill the device's data buffer.
1313    Once it completes, calling scsi_req_continue will restart I/O.  */
1314 void scsi_req_data(SCSIRequest *req, int len)
1315 {
1316     uint8_t *buf;
1317     if (req->io_canceled) {
1318         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1319         return;
1320     }
1321     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1322     assert(req->cmd.mode != SCSI_XFER_NONE);
1323     if (!req->sg) {
1324         req->resid -= len;
1325         req->bus->info->transfer_data(req, len);
1326         return;
1327     }
1328 
1329     /* If the device calls scsi_req_data and the HBA specified a
1330      * scatter/gather list, the transfer has to happen in a single
1331      * step.  */
1332     assert(!req->dma_started);
1333     req->dma_started = true;
1334 
1335     buf = scsi_req_get_buf(req);
1336     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1337         req->resid = dma_buf_read(buf, len, req->sg);
1338     } else {
1339         req->resid = dma_buf_write(buf, len, req->sg);
1340     }
1341     scsi_req_continue(req);
1342 }
1343 
1344 void scsi_req_print(SCSIRequest *req)
1345 {
1346     FILE *fp = stderr;
1347     int i;
1348 
1349     fprintf(fp, "[%s id=%d] %s",
1350             req->dev->qdev.parent_bus->name,
1351             req->dev->id,
1352             scsi_command_name(req->cmd.buf[0]));
1353     for (i = 1; i < req->cmd.len; i++) {
1354         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1355     }
1356     switch (req->cmd.mode) {
1357     case SCSI_XFER_NONE:
1358         fprintf(fp, " - none\n");
1359         break;
1360     case SCSI_XFER_FROM_DEV:
1361         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1362         break;
1363     case SCSI_XFER_TO_DEV:
1364         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1365         break;
1366     default:
1367         fprintf(fp, " - Oops\n");
1368         break;
1369     }
1370 }
1371 
1372 void scsi_req_complete(SCSIRequest *req, int status)
1373 {
1374     assert(req->status == -1);
1375     req->status = status;
1376 
1377     assert(req->sense_len <= sizeof(req->sense));
1378     if (status == GOOD) {
1379         req->sense_len = 0;
1380     }
1381 
1382     if (req->sense_len) {
1383         memcpy(req->dev->sense, req->sense, req->sense_len);
1384         req->dev->sense_len = req->sense_len;
1385         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1386     } else {
1387         req->dev->sense_len = 0;
1388         req->dev->sense_is_ua = false;
1389     }
1390 
1391     /*
1392      * Unit attention state is now stored in the device's sense buffer
1393      * if the HBA didn't do autosense.  Clear the pending unit attention
1394      * flags.
1395      */
1396     scsi_clear_unit_attention(req);
1397 
1398     scsi_req_ref(req);
1399     scsi_req_dequeue(req);
1400     req->bus->info->complete(req, req->status, req->resid);
1401 
1402     /* Cancelled requests might end up being completed instead of cancelled */
1403     notifier_list_notify(&req->cancel_notifiers, req);
1404     scsi_req_unref(req);
1405 }
1406 
1407 /* Called by the devices when the request is canceled. */
1408 void scsi_req_cancel_complete(SCSIRequest *req)
1409 {
1410     assert(req->io_canceled);
1411     if (req->bus->info->cancel) {
1412         req->bus->info->cancel(req);
1413     }
1414     notifier_list_notify(&req->cancel_notifiers, req);
1415     scsi_req_unref(req);
1416 }
1417 
1418 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1419  * notifier list, the bus will be notified the requests cancellation is
1420  * completed.
1421  * */
1422 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1423 {
1424     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1425     if (notifier) {
1426         notifier_list_add(&req->cancel_notifiers, notifier);
1427     }
1428     if (req->io_canceled) {
1429         /* A blk_aio_cancel_async is pending; when it finishes,
1430          * scsi_req_cancel_complete will be called and will
1431          * call the notifier we just added.  Just wait for that.
1432          */
1433         assert(req->aiocb);
1434         return;
1435     }
1436     /* Dropped in scsi_req_cancel_complete.  */
1437     scsi_req_ref(req);
1438     scsi_req_dequeue(req);
1439     req->io_canceled = true;
1440     if (req->aiocb) {
1441         blk_aio_cancel_async(req->aiocb);
1442     } else {
1443         scsi_req_cancel_complete(req);
1444     }
1445 }
1446 
1447 void scsi_req_cancel(SCSIRequest *req)
1448 {
1449     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1450     if (!req->enqueued) {
1451         return;
1452     }
1453     assert(!req->io_canceled);
1454     /* Dropped in scsi_req_cancel_complete.  */
1455     scsi_req_ref(req);
1456     scsi_req_dequeue(req);
1457     req->io_canceled = true;
1458     if (req->aiocb) {
1459         blk_aio_cancel(req->aiocb);
1460     } else {
1461         scsi_req_cancel_complete(req);
1462     }
1463 }
1464 
1465 static int scsi_ua_precedence(SCSISense sense)
1466 {
1467     if (sense.key != UNIT_ATTENTION) {
1468         return INT_MAX;
1469     }
1470     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1471         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1472         return 1;
1473     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1474         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1475         return 2;
1476     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1477         /* These two go with "all others". */
1478         ;
1479     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1480         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1481          * POWER ON OCCURRED = 1
1482          * SCSI BUS RESET OCCURRED = 2
1483          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1484          * I_T NEXUS LOSS OCCURRED = 7
1485          */
1486         return sense.ascq;
1487     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1488         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1489         return 8;
1490     }
1491     return (sense.asc << 8) | sense.ascq;
1492 }
1493 
1494 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1495 {
1496     int prec1, prec2;
1497     if (sense.key != UNIT_ATTENTION) {
1498         return;
1499     }
1500     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1501                              sense.asc, sense.ascq);
1502 
1503     /*
1504      * Override a pre-existing unit attention condition, except for a more
1505      * important reset condition.
1506     */
1507     prec1 = scsi_ua_precedence(sdev->unit_attention);
1508     prec2 = scsi_ua_precedence(sense);
1509     if (prec2 < prec1) {
1510         sdev->unit_attention = sense;
1511     }
1512 }
1513 
1514 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1515 {
1516     SCSIRequest *req;
1517 
1518     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1519     while (!QTAILQ_EMPTY(&sdev->requests)) {
1520         req = QTAILQ_FIRST(&sdev->requests);
1521         scsi_req_cancel_async(req, NULL);
1522     }
1523     blk_drain(sdev->conf.blk);
1524     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1525     scsi_device_set_ua(sdev, sense);
1526 }
1527 
1528 static char *scsibus_get_dev_path(DeviceState *dev)
1529 {
1530     SCSIDevice *d = SCSI_DEVICE(dev);
1531     DeviceState *hba = dev->parent_bus->parent;
1532     char *id;
1533     char *path;
1534 
1535     id = qdev_get_dev_path(hba);
1536     if (id) {
1537         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1538     } else {
1539         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1540     }
1541     g_free(id);
1542     return path;
1543 }
1544 
1545 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1546 {
1547     SCSIDevice *d = SCSI_DEVICE(dev);
1548     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1549                            qdev_fw_name(dev), d->id, d->lun);
1550 }
1551 
1552 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
1553 {
1554     BusChild *kid;
1555     SCSIDevice *target_dev = NULL;
1556 
1557     QTAILQ_FOREACH_REVERSE(kid, &bus->qbus.children, sibling) {
1558         DeviceState *qdev = kid->child;
1559         SCSIDevice *dev = SCSI_DEVICE(qdev);
1560 
1561         if (dev->channel == channel && dev->id == id) {
1562             if (dev->lun == lun) {
1563                 return dev;
1564             }
1565             target_dev = dev;
1566         }
1567     }
1568     return target_dev;
1569 }
1570 
1571 /* SCSI request list.  For simplicity, pv points to the whole device */
1572 
1573 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1574                              const VMStateField *field, QJSON *vmdesc)
1575 {
1576     SCSIDevice *s = pv;
1577     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1578     SCSIRequest *req;
1579 
1580     QTAILQ_FOREACH(req, &s->requests, next) {
1581         assert(!req->io_canceled);
1582         assert(req->status == -1);
1583         assert(req->enqueued);
1584 
1585         qemu_put_sbyte(f, req->retry ? 1 : 2);
1586         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1587         qemu_put_be32s(f, &req->tag);
1588         qemu_put_be32s(f, &req->lun);
1589         if (bus->info->save_request) {
1590             bus->info->save_request(f, req);
1591         }
1592         if (req->ops->save_request) {
1593             req->ops->save_request(f, req);
1594         }
1595     }
1596     qemu_put_sbyte(f, 0);
1597 
1598     return 0;
1599 }
1600 
1601 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1602                              const VMStateField *field)
1603 {
1604     SCSIDevice *s = pv;
1605     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1606     int8_t sbyte;
1607 
1608     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1609         uint8_t buf[SCSI_CMD_BUF_SIZE];
1610         uint32_t tag;
1611         uint32_t lun;
1612         SCSIRequest *req;
1613 
1614         qemu_get_buffer(f, buf, sizeof(buf));
1615         qemu_get_be32s(f, &tag);
1616         qemu_get_be32s(f, &lun);
1617         req = scsi_req_new(s, tag, lun, buf, NULL);
1618         req->retry = (sbyte == 1);
1619         if (bus->info->load_request) {
1620             req->hba_private = bus->info->load_request(f, req);
1621         }
1622         if (req->ops->load_request) {
1623             req->ops->load_request(f, req);
1624         }
1625 
1626         /* Just restart it later.  */
1627         scsi_req_enqueue_internal(req);
1628 
1629         /* At this point, the request will be kept alive by the reference
1630          * added by scsi_req_enqueue_internal, so we can release our reference.
1631          * The HBA of course will add its own reference in the load_request
1632          * callback if it needs to hold on the SCSIRequest.
1633          */
1634         scsi_req_unref(req);
1635     }
1636 
1637     return 0;
1638 }
1639 
1640 static const VMStateInfo vmstate_info_scsi_requests = {
1641     .name = "scsi-requests",
1642     .get  = get_scsi_requests,
1643     .put  = put_scsi_requests,
1644 };
1645 
1646 static bool scsi_sense_state_needed(void *opaque)
1647 {
1648     SCSIDevice *s = opaque;
1649 
1650     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1651 }
1652 
1653 static const VMStateDescription vmstate_scsi_sense_state = {
1654     .name = "SCSIDevice/sense",
1655     .version_id = 1,
1656     .minimum_version_id = 1,
1657     .needed = scsi_sense_state_needed,
1658     .fields = (VMStateField[]) {
1659         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1660                                 SCSI_SENSE_BUF_SIZE_OLD,
1661                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1662         VMSTATE_END_OF_LIST()
1663     }
1664 };
1665 
1666 const VMStateDescription vmstate_scsi_device = {
1667     .name = "SCSIDevice",
1668     .version_id = 1,
1669     .minimum_version_id = 1,
1670     .fields = (VMStateField[]) {
1671         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1672         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1673         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1674         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1675         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1676         VMSTATE_UINT32(sense_len, SCSIDevice),
1677         {
1678             .name         = "requests",
1679             .version_id   = 0,
1680             .field_exists = NULL,
1681             .size         = 0,   /* ouch */
1682             .info         = &vmstate_info_scsi_requests,
1683             .flags        = VMS_SINGLE,
1684             .offset       = 0,
1685         },
1686         VMSTATE_END_OF_LIST()
1687     },
1688     .subsections = (const VMStateDescription*[]) {
1689         &vmstate_scsi_sense_state,
1690         NULL
1691     }
1692 };
1693 
1694 static void scsi_device_class_init(ObjectClass *klass, void *data)
1695 {
1696     DeviceClass *k = DEVICE_CLASS(klass);
1697     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1698     k->bus_type  = TYPE_SCSI_BUS;
1699     k->realize   = scsi_qdev_realize;
1700     k->unrealize = scsi_qdev_unrealize;
1701     k->props     = scsi_props;
1702 }
1703 
1704 static void scsi_dev_instance_init(Object *obj)
1705 {
1706     DeviceState *dev = DEVICE(obj);
1707     SCSIDevice *s = SCSI_DEVICE(dev);
1708 
1709     device_add_bootindex_property(obj, &s->conf.bootindex,
1710                                   "bootindex", NULL,
1711                                   &s->qdev, NULL);
1712 }
1713 
1714 static const TypeInfo scsi_device_type_info = {
1715     .name = TYPE_SCSI_DEVICE,
1716     .parent = TYPE_DEVICE,
1717     .instance_size = sizeof(SCSIDevice),
1718     .abstract = true,
1719     .class_size = sizeof(SCSIDeviceClass),
1720     .class_init = scsi_device_class_init,
1721     .instance_init = scsi_dev_instance_init,
1722 };
1723 
1724 static void scsi_register_types(void)
1725 {
1726     type_register_static(&scsi_bus_info);
1727     type_register_static(&scsi_device_type_info);
1728 }
1729 
1730 type_init(scsi_register_types)
1731