xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision f1733749)
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 int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
63                        void *hba_private)
64 {
65     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
66     int rc;
67 
68     assert(cmd->len == 0);
69     rc = scsi_req_parse_cdb(dev, cmd, buf);
70     if (bus->info->parse_cdb) {
71         rc = bus->info->parse_cdb(dev, cmd, buf, hba_private);
72     }
73     return rc;
74 }
75 
76 static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
77                                           uint8_t *buf, void *hba_private)
78 {
79     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
80     if (sc->alloc_req) {
81         return sc->alloc_req(s, tag, lun, buf, hba_private);
82     }
83 
84     return NULL;
85 }
86 
87 void scsi_device_unit_attention_reported(SCSIDevice *s)
88 {
89     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
90     if (sc->unit_attention_reported) {
91         sc->unit_attention_reported(s);
92     }
93 }
94 
95 /* Create a scsi bus, and attach devices to it.  */
96 void scsi_bus_new(SCSIBus *bus, size_t bus_size, DeviceState *host,
97                   const SCSIBusInfo *info, const char *bus_name)
98 {
99     qbus_create_inplace(bus, bus_size, TYPE_SCSI_BUS, host, bus_name);
100     bus->busnr = next_scsi_bus++;
101     bus->info = info;
102     qbus_set_bus_hotplug_handler(BUS(bus), &error_abort);
103 }
104 
105 static void scsi_dma_restart_bh(void *opaque)
106 {
107     SCSIDevice *s = opaque;
108     SCSIRequest *req, *next;
109 
110     qemu_bh_delete(s->bh);
111     s->bh = NULL;
112 
113     aio_context_acquire(blk_get_aio_context(s->conf.blk));
114     QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
115         scsi_req_ref(req);
116         if (req->retry) {
117             req->retry = false;
118             switch (req->cmd.mode) {
119             case SCSI_XFER_FROM_DEV:
120             case SCSI_XFER_TO_DEV:
121                 scsi_req_continue(req);
122                 break;
123             case SCSI_XFER_NONE:
124                 scsi_req_dequeue(req);
125                 scsi_req_enqueue(req);
126                 break;
127             }
128         }
129         scsi_req_unref(req);
130     }
131     aio_context_release(blk_get_aio_context(s->conf.blk));
132 }
133 
134 void scsi_req_retry(SCSIRequest *req)
135 {
136     /* No need to save a reference, because scsi_dma_restart_bh just
137      * looks at the request list.  */
138     req->retry = true;
139 }
140 
141 static void scsi_dma_restart_cb(void *opaque, int running, RunState state)
142 {
143     SCSIDevice *s = opaque;
144 
145     if (!running) {
146         return;
147     }
148     if (!s->bh) {
149         AioContext *ctx = blk_get_aio_context(s->conf.blk);
150         s->bh = aio_bh_new(ctx, scsi_dma_restart_bh, s);
151         qemu_bh_schedule(s->bh);
152     }
153 }
154 
155 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
156 {
157     SCSIDevice *dev = SCSI_DEVICE(qdev);
158     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
159     SCSIDevice *d;
160     Error *local_err = NULL;
161 
162     if (dev->channel > bus->info->max_channel) {
163         error_setg(errp, "bad scsi channel id: %d", dev->channel);
164         return;
165     }
166     if (dev->id != -1 && dev->id > bus->info->max_target) {
167         error_setg(errp, "bad scsi device id: %d", dev->id);
168         return;
169     }
170     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
171         error_setg(errp, "bad scsi device lun: %d", dev->lun);
172         return;
173     }
174 
175     if (dev->id == -1) {
176         int id = -1;
177         if (dev->lun == -1) {
178             dev->lun = 0;
179         }
180         do {
181             d = scsi_device_find(bus, dev->channel, ++id, dev->lun);
182         } while (d && d->lun == dev->lun && id < bus->info->max_target);
183         if (d && d->lun == dev->lun) {
184             error_setg(errp, "no free target");
185             return;
186         }
187         dev->id = id;
188     } else if (dev->lun == -1) {
189         int lun = -1;
190         do {
191             d = scsi_device_find(bus, dev->channel, dev->id, ++lun);
192         } while (d && d->lun == lun && lun < bus->info->max_lun);
193         if (d && d->lun == lun) {
194             error_setg(errp, "no free lun");
195             return;
196         }
197         dev->lun = lun;
198     } else {
199         d = scsi_device_find(bus, dev->channel, dev->id, dev->lun);
200         assert(d);
201         if (d->lun == dev->lun && dev != d) {
202             error_setg(errp, "lun already used by '%s'", d->qdev.id);
203             return;
204         }
205     }
206 
207     QTAILQ_INIT(&dev->requests);
208     scsi_device_realize(dev, &local_err);
209     if (local_err) {
210         error_propagate(errp, local_err);
211         return;
212     }
213     dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
214             scsi_dma_restart_cb, dev);
215 }
216 
217 static void scsi_qdev_unrealize(DeviceState *qdev, Error **errp)
218 {
219     SCSIDevice *dev = SCSI_DEVICE(qdev);
220 
221     if (dev->vmsentry) {
222         qemu_del_vm_change_state_handler(dev->vmsentry);
223     }
224 
225     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
226     blockdev_mark_auto_del(dev->conf.blk);
227 }
228 
229 /* handle legacy '-drive if=scsi,...' cmd line args */
230 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
231                                       int unit, bool removable, int bootindex,
232                                       bool share_rw,
233                                       BlockdevOnError rerror,
234                                       BlockdevOnError werror,
235                                       const char *serial, Error **errp)
236 {
237     const char *driver;
238     char *name;
239     DeviceState *dev;
240     Error *err = NULL;
241 
242     driver = blk_is_sg(blk) ? "scsi-generic" : "scsi-disk";
243     dev = qdev_create(&bus->qbus, driver);
244     name = g_strdup_printf("legacy[%d]", unit);
245     object_property_add_child(OBJECT(bus), name, OBJECT(dev), NULL);
246     g_free(name);
247 
248     qdev_prop_set_uint32(dev, "scsi-id", unit);
249     if (bootindex >= 0) {
250         object_property_set_int(OBJECT(dev), bootindex, "bootindex",
251                                 &error_abort);
252     }
253     if (object_property_find(OBJECT(dev), "removable", NULL)) {
254         qdev_prop_set_bit(dev, "removable", removable);
255     }
256     if (serial && object_property_find(OBJECT(dev), "serial", NULL)) {
257         qdev_prop_set_string(dev, "serial", serial);
258     }
259     qdev_prop_set_drive(dev, "drive", blk, &err);
260     if (err) {
261         error_propagate(errp, err);
262         object_unparent(OBJECT(dev));
263         return NULL;
264     }
265     object_property_set_bool(OBJECT(dev), share_rw, "share-rw", &err);
266     if (err != NULL) {
267         error_propagate(errp, err);
268         object_unparent(OBJECT(dev));
269         return NULL;
270     }
271 
272     qdev_prop_set_enum(dev, "rerror", rerror);
273     qdev_prop_set_enum(dev, "werror", werror);
274 
275     object_property_set_bool(OBJECT(dev), true, "realized", &err);
276     if (err != NULL) {
277         error_propagate(errp, err);
278         object_unparent(OBJECT(dev));
279         return NULL;
280     }
281     return SCSI_DEVICE(dev);
282 }
283 
284 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
285 {
286     Location loc;
287     DriveInfo *dinfo;
288     int unit;
289 
290     loc_push_none(&loc);
291     for (unit = 0; unit <= bus->info->max_target; unit++) {
292         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
293         if (dinfo == NULL) {
294             continue;
295         }
296         qemu_opts_loc_restore(dinfo->opts);
297         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
298                                   unit, false, -1, false,
299                                   BLOCKDEV_ON_ERROR_AUTO,
300                                   BLOCKDEV_ON_ERROR_AUTO,
301                                   NULL, &error_fatal);
302     }
303     loc_pop(&loc);
304 }
305 
306 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
307 {
308     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
309     scsi_req_complete(req, CHECK_CONDITION);
310     return 0;
311 }
312 
313 static const struct SCSIReqOps reqops_invalid_field = {
314     .size         = sizeof(SCSIRequest),
315     .send_command = scsi_invalid_field
316 };
317 
318 /* SCSIReqOps implementation for invalid commands.  */
319 
320 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
321 {
322     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
323     scsi_req_complete(req, CHECK_CONDITION);
324     return 0;
325 }
326 
327 static const struct SCSIReqOps reqops_invalid_opcode = {
328     .size         = sizeof(SCSIRequest),
329     .send_command = scsi_invalid_command
330 };
331 
332 /* SCSIReqOps implementation for unit attention conditions.  */
333 
334 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
335 {
336     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
337         scsi_req_build_sense(req, req->dev->unit_attention);
338     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
339         scsi_req_build_sense(req, req->bus->unit_attention);
340     }
341     scsi_req_complete(req, CHECK_CONDITION);
342     return 0;
343 }
344 
345 static const struct SCSIReqOps reqops_unit_attention = {
346     .size         = sizeof(SCSIRequest),
347     .send_command = scsi_unit_attention
348 };
349 
350 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
351    an invalid LUN.  */
352 
353 typedef struct SCSITargetReq SCSITargetReq;
354 
355 struct SCSITargetReq {
356     SCSIRequest req;
357     int len;
358     uint8_t *buf;
359     int buf_len;
360 };
361 
362 static void store_lun(uint8_t *outbuf, int lun)
363 {
364     if (lun < 256) {
365         outbuf[1] = lun;
366         return;
367     }
368     outbuf[1] = (lun & 255);
369     outbuf[0] = (lun >> 8) | 0x40;
370 }
371 
372 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
373 {
374     BusChild *kid;
375     int i, len, n;
376     int channel, id;
377     bool found_lun0;
378 
379     if (r->req.cmd.xfer < 16) {
380         return false;
381     }
382     if (r->req.cmd.buf[2] > 2) {
383         return false;
384     }
385     channel = r->req.dev->channel;
386     id = r->req.dev->id;
387     found_lun0 = false;
388     n = 0;
389     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
390         DeviceState *qdev = kid->child;
391         SCSIDevice *dev = SCSI_DEVICE(qdev);
392 
393         if (dev->channel == channel && dev->id == id) {
394             if (dev->lun == 0) {
395                 found_lun0 = true;
396             }
397             n += 8;
398         }
399     }
400     if (!found_lun0) {
401         n += 8;
402     }
403 
404     scsi_target_alloc_buf(&r->req, n + 8);
405 
406     len = MIN(n + 8, r->req.cmd.xfer & ~7);
407     memset(r->buf, 0, len);
408     stl_be_p(&r->buf[0], n);
409     i = found_lun0 ? 8 : 16;
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             store_lun(&r->buf[i], dev->lun);
416             i += 8;
417         }
418     }
419     assert(i == n + 8);
420     r->len = len;
421     return true;
422 }
423 
424 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
425 {
426     assert(r->req.dev->lun != r->req.lun);
427 
428     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
429 
430     if (r->req.cmd.buf[1] & 0x2) {
431         /* Command support data - optional, not implemented */
432         return false;
433     }
434 
435     if (r->req.cmd.buf[1] & 0x1) {
436         /* Vital product data */
437         uint8_t page_code = r->req.cmd.buf[2];
438         r->buf[r->len++] = page_code ; /* this page */
439         r->buf[r->len++] = 0x00;
440 
441         switch (page_code) {
442         case 0x00: /* Supported page codes, mandatory */
443         {
444             int pages;
445             pages = r->len++;
446             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
447             r->buf[pages] = r->len - pages - 1; /* number of pages */
448             break;
449         }
450         default:
451             return false;
452         }
453         /* done with EVPD */
454         assert(r->len < r->buf_len);
455         r->len = MIN(r->req.cmd.xfer, r->len);
456         return true;
457     }
458 
459     /* Standard INQUIRY data */
460     if (r->req.cmd.buf[2] != 0) {
461         return false;
462     }
463 
464     /* PAGE CODE == 0 */
465     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
466     memset(r->buf, 0, r->len);
467     if (r->req.lun != 0) {
468         r->buf[0] = TYPE_NO_LUN;
469     } else {
470         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
471         r->buf[2] = 5; /* Version */
472         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
473         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
474         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
475         memcpy(&r->buf[8], "QEMU    ", 8);
476         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
477         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
478     }
479     return true;
480 }
481 
482 static size_t scsi_sense_len(SCSIRequest *req)
483 {
484     if (req->dev->type == TYPE_SCANNER)
485         return SCSI_SENSE_LEN_SCANNER;
486     else
487         return SCSI_SENSE_LEN;
488 }
489 
490 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
491 {
492     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
493     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
494 
495     if (req->lun != 0 &&
496         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
497         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
498         scsi_req_complete(req, CHECK_CONDITION);
499         return 0;
500     }
501     switch (buf[0]) {
502     case REPORT_LUNS:
503         if (!scsi_target_emulate_report_luns(r)) {
504             goto illegal_request;
505         }
506         break;
507     case INQUIRY:
508         if (!scsi_target_emulate_inquiry(r)) {
509             goto illegal_request;
510         }
511         break;
512     case REQUEST_SENSE:
513         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
514         if (req->lun != 0) {
515             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
516 
517             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
518                                           sense, fixed_sense);
519         } else {
520             r->len = scsi_device_get_sense(r->req.dev, r->buf,
521                                            MIN(req->cmd.xfer, r->buf_len),
522                                            fixed_sense);
523         }
524         if (r->req.dev->sense_is_ua) {
525             scsi_device_unit_attention_reported(req->dev);
526             r->req.dev->sense_len = 0;
527             r->req.dev->sense_is_ua = false;
528         }
529         break;
530     case TEST_UNIT_READY:
531         break;
532     default:
533         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
534         scsi_req_complete(req, CHECK_CONDITION);
535         return 0;
536     illegal_request:
537         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
538         scsi_req_complete(req, CHECK_CONDITION);
539         return 0;
540     }
541 
542     if (!r->len) {
543         scsi_req_complete(req, GOOD);
544     }
545     return r->len;
546 }
547 
548 static void scsi_target_read_data(SCSIRequest *req)
549 {
550     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
551     uint32_t n;
552 
553     n = r->len;
554     if (n > 0) {
555         r->len = 0;
556         scsi_req_data(&r->req, n);
557     } else {
558         scsi_req_complete(&r->req, GOOD);
559     }
560 }
561 
562 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
563 {
564     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
565 
566     return r->buf;
567 }
568 
569 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
570 {
571     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
572 
573     r->buf = g_malloc(len);
574     r->buf_len = len;
575 
576     return r->buf;
577 }
578 
579 static void scsi_target_free_buf(SCSIRequest *req)
580 {
581     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
582 
583     g_free(r->buf);
584 }
585 
586 static const struct SCSIReqOps reqops_target_command = {
587     .size         = sizeof(SCSITargetReq),
588     .send_command = scsi_target_send_command,
589     .read_data    = scsi_target_read_data,
590     .get_buf      = scsi_target_get_buf,
591     .free_req     = scsi_target_free_buf,
592 };
593 
594 
595 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
596                             uint32_t tag, uint32_t lun, void *hba_private)
597 {
598     SCSIRequest *req;
599     SCSIBus *bus = scsi_bus_from_device(d);
600     BusState *qbus = BUS(bus);
601     const int memset_off = offsetof(SCSIRequest, sense)
602                            + sizeof(req->sense);
603 
604     req = g_malloc(reqops->size);
605     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
606     req->refcount = 1;
607     req->bus = bus;
608     req->dev = d;
609     req->tag = tag;
610     req->lun = lun;
611     req->hba_private = hba_private;
612     req->status = -1;
613     req->ops = reqops;
614     object_ref(OBJECT(d));
615     object_ref(OBJECT(qbus->parent));
616     notifier_list_init(&req->cancel_notifiers);
617     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
618     return req;
619 }
620 
621 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
622                           uint8_t *buf, void *hba_private)
623 {
624     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
625     const SCSIReqOps *ops;
626     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
627     SCSIRequest *req;
628     SCSICommand cmd = { .len = 0 };
629     int ret;
630 
631     if ((d->unit_attention.key == UNIT_ATTENTION ||
632          bus->unit_attention.key == UNIT_ATTENTION) &&
633         (buf[0] != INQUIRY &&
634          buf[0] != REPORT_LUNS &&
635          buf[0] != GET_CONFIGURATION &&
636          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
637 
638          /*
639           * If we already have a pending unit attention condition,
640           * report this one before triggering another one.
641           */
642          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
643         ops = &reqops_unit_attention;
644     } else if (lun != d->lun ||
645                buf[0] == REPORT_LUNS ||
646                (buf[0] == REQUEST_SENSE && d->sense_len)) {
647         ops = &reqops_target_command;
648     } else {
649         ops = NULL;
650     }
651 
652     if (ops != NULL || !sc->parse_cdb) {
653         ret = scsi_req_parse_cdb(d, &cmd, buf);
654     } else {
655         ret = sc->parse_cdb(d, &cmd, buf, hba_private);
656     }
657 
658     if (ret != 0) {
659         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
660         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
661     } else {
662         assert(cmd.len != 0);
663         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
664                               cmd.mode, cmd.xfer);
665         if (cmd.lba != -1) {
666             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
667                                       cmd.lba);
668         }
669 
670         if (cmd.xfer > INT32_MAX) {
671             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
672         } else if (ops) {
673             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
674         } else {
675             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
676         }
677     }
678 
679     req->cmd = cmd;
680     req->resid = req->cmd.xfer;
681 
682     switch (buf[0]) {
683     case INQUIRY:
684         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
685         break;
686     case TEST_UNIT_READY:
687         trace_scsi_test_unit_ready(d->id, lun, tag);
688         break;
689     case REPORT_LUNS:
690         trace_scsi_report_luns(d->id, lun, tag);
691         break;
692     case REQUEST_SENSE:
693         trace_scsi_request_sense(d->id, lun, tag);
694         break;
695     default:
696         break;
697     }
698 
699     return req;
700 }
701 
702 uint8_t *scsi_req_get_buf(SCSIRequest *req)
703 {
704     return req->ops->get_buf(req);
705 }
706 
707 static void scsi_clear_unit_attention(SCSIRequest *req)
708 {
709     SCSISense *ua;
710     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
711         req->bus->unit_attention.key != UNIT_ATTENTION) {
712         return;
713     }
714 
715     /*
716      * If an INQUIRY command enters the enabled command state,
717      * the device server shall [not] clear any unit attention condition;
718      * See also MMC-6, paragraphs 6.5 and 6.6.2.
719      */
720     if (req->cmd.buf[0] == INQUIRY ||
721         req->cmd.buf[0] == GET_CONFIGURATION ||
722         req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
723         return;
724     }
725 
726     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
727         ua = &req->dev->unit_attention;
728     } else {
729         ua = &req->bus->unit_attention;
730     }
731 
732     /*
733      * If a REPORT LUNS command enters the enabled command state, [...]
734      * the device server shall clear any pending unit attention condition
735      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
736      */
737     if (req->cmd.buf[0] == REPORT_LUNS &&
738         !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
739           ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
740         return;
741     }
742 
743     *ua = SENSE_CODE(NO_SENSE);
744 }
745 
746 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
747 {
748     int ret;
749 
750     assert(len >= 14);
751     if (!req->sense_len) {
752         return 0;
753     }
754 
755     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
756 
757     /*
758      * FIXME: clearing unit attention conditions upon autosense should be done
759      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
760      * (SAM-5, 5.14).
761      *
762      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
763      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
764      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
765      */
766     if (req->dev->sense_is_ua) {
767         scsi_device_unit_attention_reported(req->dev);
768         req->dev->sense_len = 0;
769         req->dev->sense_is_ua = false;
770     }
771     return ret;
772 }
773 
774 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
775 {
776     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
777 }
778 
779 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
780 {
781     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
782                                sense.key, sense.asc, sense.ascq);
783     req->sense_len = scsi_build_sense(req->sense, sense);
784 }
785 
786 static void scsi_req_enqueue_internal(SCSIRequest *req)
787 {
788     assert(!req->enqueued);
789     scsi_req_ref(req);
790     if (req->bus->info->get_sg_list) {
791         req->sg = req->bus->info->get_sg_list(req);
792     } else {
793         req->sg = NULL;
794     }
795     req->enqueued = true;
796     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
797 }
798 
799 int32_t scsi_req_enqueue(SCSIRequest *req)
800 {
801     int32_t rc;
802 
803     assert(!req->retry);
804     scsi_req_enqueue_internal(req);
805     scsi_req_ref(req);
806     rc = req->ops->send_command(req, req->cmd.buf);
807     scsi_req_unref(req);
808     return rc;
809 }
810 
811 static void scsi_req_dequeue(SCSIRequest *req)
812 {
813     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
814     req->retry = false;
815     if (req->enqueued) {
816         QTAILQ_REMOVE(&req->dev->requests, req, next);
817         req->enqueued = false;
818         scsi_req_unref(req);
819     }
820 }
821 
822 static int scsi_get_performance_length(int num_desc, int type, int data_type)
823 {
824     /* MMC-6, paragraph 6.7.  */
825     switch (type) {
826     case 0:
827         if ((data_type & 3) == 0) {
828             /* Each descriptor is as in Table 295 - Nominal performance.  */
829             return 16 * num_desc + 8;
830         } else {
831             /* Each descriptor is as in Table 296 - Exceptions.  */
832             return 6 * num_desc + 8;
833         }
834     case 1:
835     case 4:
836     case 5:
837         return 8 * num_desc + 8;
838     case 2:
839         return 2048 * num_desc + 8;
840     case 3:
841         return 16 * num_desc + 8;
842     default:
843         return 8;
844     }
845 }
846 
847 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
848 {
849     int byte_block = (buf[2] >> 2) & 0x1;
850     int type = (buf[2] >> 4) & 0x1;
851     int xfer_unit;
852 
853     if (byte_block) {
854         if (type) {
855             xfer_unit = dev->blocksize;
856         } else {
857             xfer_unit = 512;
858         }
859     } else {
860         xfer_unit = 1;
861     }
862 
863     return xfer_unit;
864 }
865 
866 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
867 {
868     int length = buf[2] & 0x3;
869     int xfer;
870     int unit = ata_passthrough_xfer_unit(dev, buf);
871 
872     switch (length) {
873     case 0:
874     case 3: /* USB-specific.  */
875     default:
876         xfer = 0;
877         break;
878     case 1:
879         xfer = buf[3];
880         break;
881     case 2:
882         xfer = buf[4];
883         break;
884     }
885 
886     return xfer * unit;
887 }
888 
889 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
890 {
891     int extend = buf[1] & 0x1;
892     int length = buf[2] & 0x3;
893     int xfer;
894     int unit = ata_passthrough_xfer_unit(dev, buf);
895 
896     switch (length) {
897     case 0:
898     case 3: /* USB-specific.  */
899     default:
900         xfer = 0;
901         break;
902     case 1:
903         xfer = buf[4];
904         xfer |= (extend ? buf[3] << 8 : 0);
905         break;
906     case 2:
907         xfer = buf[6];
908         xfer |= (extend ? buf[5] << 8 : 0);
909         break;
910     }
911 
912     return xfer * unit;
913 }
914 
915 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
916 {
917     cmd->xfer = scsi_cdb_xfer(buf);
918     switch (buf[0]) {
919     case TEST_UNIT_READY:
920     case REWIND:
921     case START_STOP:
922     case SET_CAPACITY:
923     case WRITE_FILEMARKS:
924     case WRITE_FILEMARKS_16:
925     case SPACE:
926     case RESERVE:
927     case RELEASE:
928     case ERASE:
929     case ALLOW_MEDIUM_REMOVAL:
930     case SEEK_10:
931     case SYNCHRONIZE_CACHE:
932     case SYNCHRONIZE_CACHE_16:
933     case LOCATE_16:
934     case LOCK_UNLOCK_CACHE:
935     case SET_CD_SPEED:
936     case SET_LIMITS:
937     case WRITE_LONG_10:
938     case UPDATE_BLOCK:
939     case RESERVE_TRACK:
940     case SET_READ_AHEAD:
941     case PRE_FETCH:
942     case PRE_FETCH_16:
943     case ALLOW_OVERWRITE:
944         cmd->xfer = 0;
945         break;
946     case VERIFY_10:
947     case VERIFY_12:
948     case VERIFY_16:
949         if ((buf[1] & 2) == 0) {
950             cmd->xfer = 0;
951         } else if ((buf[1] & 4) != 0) {
952             cmd->xfer = 1;
953         }
954         cmd->xfer *= dev->blocksize;
955         break;
956     case MODE_SENSE:
957         break;
958     case WRITE_SAME_10:
959     case WRITE_SAME_16:
960         cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
961         break;
962     case READ_CAPACITY_10:
963         cmd->xfer = 8;
964         break;
965     case READ_BLOCK_LIMITS:
966         cmd->xfer = 6;
967         break;
968     case SEND_VOLUME_TAG:
969         /* GPCMD_SET_STREAMING from multimedia commands.  */
970         if (dev->type == TYPE_ROM) {
971             cmd->xfer = buf[10] | (buf[9] << 8);
972         } else {
973             cmd->xfer = buf[9] | (buf[8] << 8);
974         }
975         break;
976     case WRITE_6:
977         /* length 0 means 256 blocks */
978         if (cmd->xfer == 0) {
979             cmd->xfer = 256;
980         }
981         /* fall through */
982     case WRITE_10:
983     case WRITE_VERIFY_10:
984     case WRITE_12:
985     case WRITE_VERIFY_12:
986     case WRITE_16:
987     case WRITE_VERIFY_16:
988         cmd->xfer *= dev->blocksize;
989         break;
990     case READ_6:
991     case READ_REVERSE:
992         /* length 0 means 256 blocks */
993         if (cmd->xfer == 0) {
994             cmd->xfer = 256;
995         }
996         /* fall through */
997     case READ_10:
998     case READ_12:
999     case READ_16:
1000         cmd->xfer *= dev->blocksize;
1001         break;
1002     case FORMAT_UNIT:
1003         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1004          * for block devices are restricted to the header right now.  */
1005         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1006             cmd->xfer = 12;
1007         } else {
1008             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1009         }
1010         break;
1011     case INQUIRY:
1012     case RECEIVE_DIAGNOSTIC:
1013     case SEND_DIAGNOSTIC:
1014         cmd->xfer = buf[4] | (buf[3] << 8);
1015         break;
1016     case READ_CD:
1017     case READ_BUFFER:
1018     case WRITE_BUFFER:
1019     case SEND_CUE_SHEET:
1020         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1021         break;
1022     case PERSISTENT_RESERVE_OUT:
1023         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1024         break;
1025     case ERASE_12:
1026         if (dev->type == TYPE_ROM) {
1027             /* MMC command GET PERFORMANCE.  */
1028             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1029                                                     buf[10], buf[1] & 0x1f);
1030         }
1031         break;
1032     case MECHANISM_STATUS:
1033     case READ_DVD_STRUCTURE:
1034     case SEND_DVD_STRUCTURE:
1035     case MAINTENANCE_OUT:
1036     case MAINTENANCE_IN:
1037         if (dev->type == TYPE_ROM) {
1038             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1039             cmd->xfer = buf[9] | (buf[8] << 8);
1040         }
1041         break;
1042     case ATA_PASSTHROUGH_12:
1043         if (dev->type == TYPE_ROM) {
1044             /* BLANK command of MMC */
1045             cmd->xfer = 0;
1046         } else {
1047             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1048         }
1049         break;
1050     case ATA_PASSTHROUGH_16:
1051         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1052         break;
1053     }
1054     return 0;
1055 }
1056 
1057 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1058 {
1059     switch (buf[0]) {
1060     /* stream commands */
1061     case ERASE_12:
1062     case ERASE_16:
1063         cmd->xfer = 0;
1064         break;
1065     case READ_6:
1066     case READ_REVERSE:
1067     case RECOVER_BUFFERED_DATA:
1068     case WRITE_6:
1069         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1070         if (buf[1] & 0x01) { /* fixed */
1071             cmd->xfer *= dev->blocksize;
1072         }
1073         break;
1074     case READ_16:
1075     case READ_REVERSE_16:
1076     case VERIFY_16:
1077     case WRITE_16:
1078         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1079         if (buf[1] & 0x01) { /* fixed */
1080             cmd->xfer *= dev->blocksize;
1081         }
1082         break;
1083     case REWIND:
1084     case LOAD_UNLOAD:
1085         cmd->xfer = 0;
1086         break;
1087     case SPACE_16:
1088         cmd->xfer = buf[13] | (buf[12] << 8);
1089         break;
1090     case READ_POSITION:
1091         switch (buf[1] & 0x1f) /* operation code */ {
1092         case SHORT_FORM_BLOCK_ID:
1093         case SHORT_FORM_VENDOR_SPECIFIC:
1094             cmd->xfer = 20;
1095             break;
1096         case LONG_FORM:
1097             cmd->xfer = 32;
1098             break;
1099         case EXTENDED_FORM:
1100             cmd->xfer = buf[8] | (buf[7] << 8);
1101             break;
1102         default:
1103             return -1;
1104         }
1105 
1106         break;
1107     case FORMAT_UNIT:
1108         cmd->xfer = buf[4] | (buf[3] << 8);
1109         break;
1110     /* generic commands */
1111     default:
1112         return scsi_req_xfer(cmd, dev, buf);
1113     }
1114     return 0;
1115 }
1116 
1117 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1118 {
1119     switch (buf[0]) {
1120     /* medium changer commands */
1121     case EXCHANGE_MEDIUM:
1122     case INITIALIZE_ELEMENT_STATUS:
1123     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1124     case MOVE_MEDIUM:
1125     case POSITION_TO_ELEMENT:
1126         cmd->xfer = 0;
1127         break;
1128     case READ_ELEMENT_STATUS:
1129         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1130         break;
1131 
1132     /* generic commands */
1133     default:
1134         return scsi_req_xfer(cmd, dev, buf);
1135     }
1136     return 0;
1137 }
1138 
1139 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1140 {
1141     switch (buf[0]) {
1142     /* Scanner commands */
1143     case OBJECT_POSITION:
1144         cmd->xfer = 0;
1145         break;
1146     case SCAN:
1147         cmd->xfer = buf[4];
1148         break;
1149     case READ_10:
1150     case SEND:
1151     case GET_WINDOW:
1152     case SET_WINDOW:
1153         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1154         break;
1155     default:
1156         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1157         return scsi_req_xfer(cmd, dev, buf);
1158     }
1159 
1160     return 0;
1161 }
1162 
1163 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1164 {
1165     if (!cmd->xfer) {
1166         cmd->mode = SCSI_XFER_NONE;
1167         return;
1168     }
1169     switch (cmd->buf[0]) {
1170     case WRITE_6:
1171     case WRITE_10:
1172     case WRITE_VERIFY_10:
1173     case WRITE_12:
1174     case WRITE_VERIFY_12:
1175     case WRITE_16:
1176     case WRITE_VERIFY_16:
1177     case VERIFY_10:
1178     case VERIFY_12:
1179     case VERIFY_16:
1180     case COPY:
1181     case COPY_VERIFY:
1182     case COMPARE:
1183     case CHANGE_DEFINITION:
1184     case LOG_SELECT:
1185     case MODE_SELECT:
1186     case MODE_SELECT_10:
1187     case SEND_DIAGNOSTIC:
1188     case WRITE_BUFFER:
1189     case FORMAT_UNIT:
1190     case REASSIGN_BLOCKS:
1191     case SEARCH_EQUAL:
1192     case SEARCH_HIGH:
1193     case SEARCH_LOW:
1194     case UPDATE_BLOCK:
1195     case WRITE_LONG_10:
1196     case WRITE_SAME_10:
1197     case WRITE_SAME_16:
1198     case UNMAP:
1199     case SEARCH_HIGH_12:
1200     case SEARCH_EQUAL_12:
1201     case SEARCH_LOW_12:
1202     case MEDIUM_SCAN:
1203     case SEND_VOLUME_TAG:
1204     case SEND_CUE_SHEET:
1205     case SEND_DVD_STRUCTURE:
1206     case PERSISTENT_RESERVE_OUT:
1207     case MAINTENANCE_OUT:
1208     case SET_WINDOW:
1209     case SCAN:
1210         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1211          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1212          */
1213         cmd->mode = SCSI_XFER_TO_DEV;
1214         break;
1215     case ATA_PASSTHROUGH_12:
1216     case ATA_PASSTHROUGH_16:
1217         /* T_DIR */
1218         cmd->mode = (cmd->buf[2] & 0x8) ?
1219                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1220         break;
1221     default:
1222         cmd->mode = SCSI_XFER_FROM_DEV;
1223         break;
1224     }
1225 }
1226 
1227 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf)
1228 {
1229     int rc;
1230     int len;
1231 
1232     cmd->lba = -1;
1233     len = scsi_cdb_length(buf);
1234     if (len < 0) {
1235         return -1;
1236     }
1237 
1238     cmd->len = len;
1239     switch (dev->type) {
1240     case TYPE_TAPE:
1241         rc = scsi_req_stream_xfer(cmd, dev, buf);
1242         break;
1243     case TYPE_MEDIUM_CHANGER:
1244         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1245         break;
1246     case TYPE_SCANNER:
1247         rc = scsi_req_scanner_length(cmd, dev, buf);
1248         break;
1249     default:
1250         rc = scsi_req_xfer(cmd, dev, buf);
1251         break;
1252     }
1253 
1254     if (rc != 0)
1255         return rc;
1256 
1257     memcpy(cmd->buf, buf, cmd->len);
1258     scsi_cmd_xfer_mode(cmd);
1259     cmd->lba = scsi_cmd_lba(cmd);
1260     return 0;
1261 }
1262 
1263 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1264 {
1265     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1266 
1267     scsi_device_set_ua(dev, sense);
1268     if (bus->info->change) {
1269         bus->info->change(bus, dev, sense);
1270     }
1271 }
1272 
1273 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1274 {
1275     assert(req->refcount > 0);
1276     req->refcount++;
1277     return req;
1278 }
1279 
1280 void scsi_req_unref(SCSIRequest *req)
1281 {
1282     assert(req->refcount > 0);
1283     if (--req->refcount == 0) {
1284         BusState *qbus = req->dev->qdev.parent_bus;
1285         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1286 
1287         if (bus->info->free_request && req->hba_private) {
1288             bus->info->free_request(bus, req->hba_private);
1289         }
1290         if (req->ops->free_req) {
1291             req->ops->free_req(req);
1292         }
1293         object_unref(OBJECT(req->dev));
1294         object_unref(OBJECT(qbus->parent));
1295         g_free(req);
1296     }
1297 }
1298 
1299 /* Tell the device that we finished processing this chunk of I/O.  It
1300    will start the next chunk or complete the command.  */
1301 void scsi_req_continue(SCSIRequest *req)
1302 {
1303     if (req->io_canceled) {
1304         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1305         return;
1306     }
1307     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1308     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1309         req->ops->write_data(req);
1310     } else {
1311         req->ops->read_data(req);
1312     }
1313 }
1314 
1315 /* Called by the devices when data is ready for the HBA.  The HBA should
1316    start a DMA operation to read or fill the device's data buffer.
1317    Once it completes, calling scsi_req_continue will restart I/O.  */
1318 void scsi_req_data(SCSIRequest *req, int len)
1319 {
1320     uint8_t *buf;
1321     if (req->io_canceled) {
1322         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1323         return;
1324     }
1325     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1326     assert(req->cmd.mode != SCSI_XFER_NONE);
1327     if (!req->sg) {
1328         req->resid -= len;
1329         req->bus->info->transfer_data(req, len);
1330         return;
1331     }
1332 
1333     /* If the device calls scsi_req_data and the HBA specified a
1334      * scatter/gather list, the transfer has to happen in a single
1335      * step.  */
1336     assert(!req->dma_started);
1337     req->dma_started = true;
1338 
1339     buf = scsi_req_get_buf(req);
1340     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1341         req->resid = dma_buf_read(buf, len, req->sg);
1342     } else {
1343         req->resid = dma_buf_write(buf, len, req->sg);
1344     }
1345     scsi_req_continue(req);
1346 }
1347 
1348 void scsi_req_print(SCSIRequest *req)
1349 {
1350     FILE *fp = stderr;
1351     int i;
1352 
1353     fprintf(fp, "[%s id=%d] %s",
1354             req->dev->qdev.parent_bus->name,
1355             req->dev->id,
1356             scsi_command_name(req->cmd.buf[0]));
1357     for (i = 1; i < req->cmd.len; i++) {
1358         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1359     }
1360     switch (req->cmd.mode) {
1361     case SCSI_XFER_NONE:
1362         fprintf(fp, " - none\n");
1363         break;
1364     case SCSI_XFER_FROM_DEV:
1365         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1366         break;
1367     case SCSI_XFER_TO_DEV:
1368         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1369         break;
1370     default:
1371         fprintf(fp, " - Oops\n");
1372         break;
1373     }
1374 }
1375 
1376 void scsi_req_complete(SCSIRequest *req, int status)
1377 {
1378     assert(req->status == -1);
1379     req->status = status;
1380 
1381     assert(req->sense_len <= sizeof(req->sense));
1382     if (status == GOOD) {
1383         req->sense_len = 0;
1384     }
1385 
1386     if (req->sense_len) {
1387         memcpy(req->dev->sense, req->sense, req->sense_len);
1388         req->dev->sense_len = req->sense_len;
1389         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1390     } else {
1391         req->dev->sense_len = 0;
1392         req->dev->sense_is_ua = false;
1393     }
1394 
1395     /*
1396      * Unit attention state is now stored in the device's sense buffer
1397      * if the HBA didn't do autosense.  Clear the pending unit attention
1398      * flags.
1399      */
1400     scsi_clear_unit_attention(req);
1401 
1402     scsi_req_ref(req);
1403     scsi_req_dequeue(req);
1404     req->bus->info->complete(req, req->status, req->resid);
1405 
1406     /* Cancelled requests might end up being completed instead of cancelled */
1407     notifier_list_notify(&req->cancel_notifiers, req);
1408     scsi_req_unref(req);
1409 }
1410 
1411 /* Called by the devices when the request is canceled. */
1412 void scsi_req_cancel_complete(SCSIRequest *req)
1413 {
1414     assert(req->io_canceled);
1415     if (req->bus->info->cancel) {
1416         req->bus->info->cancel(req);
1417     }
1418     notifier_list_notify(&req->cancel_notifiers, req);
1419     scsi_req_unref(req);
1420 }
1421 
1422 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1423  * notifier list, the bus will be notified the requests cancellation is
1424  * completed.
1425  * */
1426 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1427 {
1428     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1429     if (notifier) {
1430         notifier_list_add(&req->cancel_notifiers, notifier);
1431     }
1432     if (req->io_canceled) {
1433         /* A blk_aio_cancel_async is pending; when it finishes,
1434          * scsi_req_cancel_complete will be called and will
1435          * call the notifier we just added.  Just wait for that.
1436          */
1437         assert(req->aiocb);
1438         return;
1439     }
1440     /* Dropped in scsi_req_cancel_complete.  */
1441     scsi_req_ref(req);
1442     scsi_req_dequeue(req);
1443     req->io_canceled = true;
1444     if (req->aiocb) {
1445         blk_aio_cancel_async(req->aiocb);
1446     } else {
1447         scsi_req_cancel_complete(req);
1448     }
1449 }
1450 
1451 void scsi_req_cancel(SCSIRequest *req)
1452 {
1453     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1454     if (!req->enqueued) {
1455         return;
1456     }
1457     assert(!req->io_canceled);
1458     /* Dropped in scsi_req_cancel_complete.  */
1459     scsi_req_ref(req);
1460     scsi_req_dequeue(req);
1461     req->io_canceled = true;
1462     if (req->aiocb) {
1463         blk_aio_cancel(req->aiocb);
1464     } else {
1465         scsi_req_cancel_complete(req);
1466     }
1467 }
1468 
1469 static int scsi_ua_precedence(SCSISense sense)
1470 {
1471     if (sense.key != UNIT_ATTENTION) {
1472         return INT_MAX;
1473     }
1474     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1475         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1476         return 1;
1477     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1478         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1479         return 2;
1480     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1481         /* These two go with "all others". */
1482         ;
1483     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1484         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1485          * POWER ON OCCURRED = 1
1486          * SCSI BUS RESET OCCURRED = 2
1487          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1488          * I_T NEXUS LOSS OCCURRED = 7
1489          */
1490         return sense.ascq;
1491     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1492         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1493         return 8;
1494     }
1495     return (sense.asc << 8) | sense.ascq;
1496 }
1497 
1498 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1499 {
1500     int prec1, prec2;
1501     if (sense.key != UNIT_ATTENTION) {
1502         return;
1503     }
1504     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1505                              sense.asc, sense.ascq);
1506 
1507     /*
1508      * Override a pre-existing unit attention condition, except for a more
1509      * important reset condition.
1510     */
1511     prec1 = scsi_ua_precedence(sdev->unit_attention);
1512     prec2 = scsi_ua_precedence(sense);
1513     if (prec2 < prec1) {
1514         sdev->unit_attention = sense;
1515     }
1516 }
1517 
1518 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1519 {
1520     SCSIRequest *req;
1521 
1522     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1523     while (!QTAILQ_EMPTY(&sdev->requests)) {
1524         req = QTAILQ_FIRST(&sdev->requests);
1525         scsi_req_cancel_async(req, NULL);
1526     }
1527     blk_drain(sdev->conf.blk);
1528     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1529     scsi_device_set_ua(sdev, sense);
1530 }
1531 
1532 static char *scsibus_get_dev_path(DeviceState *dev)
1533 {
1534     SCSIDevice *d = SCSI_DEVICE(dev);
1535     DeviceState *hba = dev->parent_bus->parent;
1536     char *id;
1537     char *path;
1538 
1539     id = qdev_get_dev_path(hba);
1540     if (id) {
1541         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1542     } else {
1543         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1544     }
1545     g_free(id);
1546     return path;
1547 }
1548 
1549 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1550 {
1551     SCSIDevice *d = SCSI_DEVICE(dev);
1552     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1553                            qdev_fw_name(dev), d->id, d->lun);
1554 }
1555 
1556 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
1557 {
1558     BusChild *kid;
1559     SCSIDevice *target_dev = NULL;
1560 
1561     QTAILQ_FOREACH_REVERSE(kid, &bus->qbus.children, sibling) {
1562         DeviceState *qdev = kid->child;
1563         SCSIDevice *dev = SCSI_DEVICE(qdev);
1564 
1565         if (dev->channel == channel && dev->id == id) {
1566             if (dev->lun == lun) {
1567                 return dev;
1568             }
1569             target_dev = dev;
1570         }
1571     }
1572     return target_dev;
1573 }
1574 
1575 /* SCSI request list.  For simplicity, pv points to the whole device */
1576 
1577 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1578                              const VMStateField *field, QJSON *vmdesc)
1579 {
1580     SCSIDevice *s = pv;
1581     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1582     SCSIRequest *req;
1583 
1584     QTAILQ_FOREACH(req, &s->requests, next) {
1585         assert(!req->io_canceled);
1586         assert(req->status == -1);
1587         assert(req->enqueued);
1588 
1589         qemu_put_sbyte(f, req->retry ? 1 : 2);
1590         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1591         qemu_put_be32s(f, &req->tag);
1592         qemu_put_be32s(f, &req->lun);
1593         if (bus->info->save_request) {
1594             bus->info->save_request(f, req);
1595         }
1596         if (req->ops->save_request) {
1597             req->ops->save_request(f, req);
1598         }
1599     }
1600     qemu_put_sbyte(f, 0);
1601 
1602     return 0;
1603 }
1604 
1605 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1606                              const VMStateField *field)
1607 {
1608     SCSIDevice *s = pv;
1609     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1610     int8_t sbyte;
1611 
1612     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1613         uint8_t buf[SCSI_CMD_BUF_SIZE];
1614         uint32_t tag;
1615         uint32_t lun;
1616         SCSIRequest *req;
1617 
1618         qemu_get_buffer(f, buf, sizeof(buf));
1619         qemu_get_be32s(f, &tag);
1620         qemu_get_be32s(f, &lun);
1621         req = scsi_req_new(s, tag, lun, buf, NULL);
1622         req->retry = (sbyte == 1);
1623         if (bus->info->load_request) {
1624             req->hba_private = bus->info->load_request(f, req);
1625         }
1626         if (req->ops->load_request) {
1627             req->ops->load_request(f, req);
1628         }
1629 
1630         /* Just restart it later.  */
1631         scsi_req_enqueue_internal(req);
1632 
1633         /* At this point, the request will be kept alive by the reference
1634          * added by scsi_req_enqueue_internal, so we can release our reference.
1635          * The HBA of course will add its own reference in the load_request
1636          * callback if it needs to hold on the SCSIRequest.
1637          */
1638         scsi_req_unref(req);
1639     }
1640 
1641     return 0;
1642 }
1643 
1644 static const VMStateInfo vmstate_info_scsi_requests = {
1645     .name = "scsi-requests",
1646     .get  = get_scsi_requests,
1647     .put  = put_scsi_requests,
1648 };
1649 
1650 static bool scsi_sense_state_needed(void *opaque)
1651 {
1652     SCSIDevice *s = opaque;
1653 
1654     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1655 }
1656 
1657 static const VMStateDescription vmstate_scsi_sense_state = {
1658     .name = "SCSIDevice/sense",
1659     .version_id = 1,
1660     .minimum_version_id = 1,
1661     .needed = scsi_sense_state_needed,
1662     .fields = (VMStateField[]) {
1663         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1664                                 SCSI_SENSE_BUF_SIZE_OLD,
1665                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1666         VMSTATE_END_OF_LIST()
1667     }
1668 };
1669 
1670 const VMStateDescription vmstate_scsi_device = {
1671     .name = "SCSIDevice",
1672     .version_id = 1,
1673     .minimum_version_id = 1,
1674     .fields = (VMStateField[]) {
1675         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1676         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1677         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1678         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1679         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1680         VMSTATE_UINT32(sense_len, SCSIDevice),
1681         {
1682             .name         = "requests",
1683             .version_id   = 0,
1684             .field_exists = NULL,
1685             .size         = 0,   /* ouch */
1686             .info         = &vmstate_info_scsi_requests,
1687             .flags        = VMS_SINGLE,
1688             .offset       = 0,
1689         },
1690         VMSTATE_END_OF_LIST()
1691     },
1692     .subsections = (const VMStateDescription*[]) {
1693         &vmstate_scsi_sense_state,
1694         NULL
1695     }
1696 };
1697 
1698 static void scsi_device_class_init(ObjectClass *klass, void *data)
1699 {
1700     DeviceClass *k = DEVICE_CLASS(klass);
1701     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1702     k->bus_type  = TYPE_SCSI_BUS;
1703     k->realize   = scsi_qdev_realize;
1704     k->unrealize = scsi_qdev_unrealize;
1705     k->props     = scsi_props;
1706 }
1707 
1708 static void scsi_dev_instance_init(Object *obj)
1709 {
1710     DeviceState *dev = DEVICE(obj);
1711     SCSIDevice *s = SCSI_DEVICE(dev);
1712 
1713     device_add_bootindex_property(obj, &s->conf.bootindex,
1714                                   "bootindex", NULL,
1715                                   &s->qdev, NULL);
1716 }
1717 
1718 static const TypeInfo scsi_device_type_info = {
1719     .name = TYPE_SCSI_DEVICE,
1720     .parent = TYPE_DEVICE,
1721     .instance_size = sizeof(SCSIDevice),
1722     .abstract = true,
1723     .class_size = sizeof(SCSIDeviceClass),
1724     .class_init = scsi_device_class_init,
1725     .instance_init = scsi_dev_instance_init,
1726 };
1727 
1728 static void scsi_register_types(void)
1729 {
1730     type_register_static(&scsi_bus_info);
1731     type_register_static(&scsi_device_type_info);
1732 }
1733 
1734 type_init(scsi_register_types)
1735