xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision e6546342)
1 #include "qemu/osdep.h"
2 #include "qapi/error.h"
3 #include "qemu/error-report.h"
4 #include "qemu/module.h"
5 #include "qemu/option.h"
6 #include "hw/qdev-properties.h"
7 #include "hw/scsi/scsi.h"
8 #include "migration/qemu-file-types.h"
9 #include "migration/vmstate.h"
10 #include "scsi/constants.h"
11 #include "sysemu/block-backend.h"
12 #include "sysemu/blockdev.h"
13 #include "sysemu/sysemu.h"
14 #include "sysemu/runstate.h"
15 #include "trace.h"
16 #include "sysemu/dma.h"
17 #include "qemu/cutils.h"
18 
19 static char *scsibus_get_dev_path(DeviceState *dev);
20 static char *scsibus_get_fw_dev_path(DeviceState *dev);
21 static void scsi_req_dequeue(SCSIRequest *req);
22 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len);
23 static void scsi_target_free_buf(SCSIRequest *req);
24 
25 static Property scsi_props[] = {
26     DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
27     DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
28     DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
29     DEFINE_PROP_END_OF_LIST(),
30 };
31 
32 static void scsi_bus_class_init(ObjectClass *klass, void *data)
33 {
34     BusClass *k = BUS_CLASS(klass);
35     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
36 
37     k->get_dev_path = scsibus_get_dev_path;
38     k->get_fw_dev_path = scsibus_get_fw_dev_path;
39     hc->unplug = qdev_simple_device_unplug_cb;
40 }
41 
42 static const TypeInfo scsi_bus_info = {
43     .name = TYPE_SCSI_BUS,
44     .parent = TYPE_BUS,
45     .instance_size = sizeof(SCSIBus),
46     .class_init = scsi_bus_class_init,
47     .interfaces = (InterfaceInfo[]) {
48         { TYPE_HOTPLUG_HANDLER },
49         { }
50     }
51 };
52 static int next_scsi_bus;
53 
54 static void scsi_device_realize(SCSIDevice *s, Error **errp)
55 {
56     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
57     if (sc->realize) {
58         sc->realize(s, errp);
59     }
60 }
61 
62 static void scsi_device_unrealize(SCSIDevice *s)
63 {
64     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
65     if (sc->unrealize) {
66         sc->unrealize(s);
67     }
68 }
69 
70 int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
71                        void *hba_private)
72 {
73     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
74     int rc;
75 
76     assert(cmd->len == 0);
77     rc = scsi_req_parse_cdb(dev, cmd, buf);
78     if (bus->info->parse_cdb) {
79         rc = bus->info->parse_cdb(dev, cmd, buf, hba_private);
80     }
81     return rc;
82 }
83 
84 static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
85                                           uint8_t *buf, void *hba_private)
86 {
87     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
88     if (sc->alloc_req) {
89         return sc->alloc_req(s, tag, lun, buf, hba_private);
90     }
91 
92     return NULL;
93 }
94 
95 void scsi_device_unit_attention_reported(SCSIDevice *s)
96 {
97     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
98     if (sc->unit_attention_reported) {
99         sc->unit_attention_reported(s);
100     }
101 }
102 
103 /* Create a scsi bus, and attach devices to it.  */
104 void scsi_bus_new(SCSIBus *bus, size_t bus_size, DeviceState *host,
105                   const SCSIBusInfo *info, const char *bus_name)
106 {
107     qbus_create_inplace(bus, bus_size, TYPE_SCSI_BUS, host, bus_name);
108     bus->busnr = next_scsi_bus++;
109     bus->info = info;
110     qbus_set_bus_hotplug_handler(BUS(bus));
111 }
112 
113 static void scsi_dma_restart_bh(void *opaque)
114 {
115     SCSIDevice *s = opaque;
116     SCSIRequest *req, *next;
117 
118     qemu_bh_delete(s->bh);
119     s->bh = NULL;
120 
121     aio_context_acquire(blk_get_aio_context(s->conf.blk));
122     QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
123         scsi_req_ref(req);
124         if (req->retry) {
125             req->retry = false;
126             switch (req->cmd.mode) {
127             case SCSI_XFER_FROM_DEV:
128             case SCSI_XFER_TO_DEV:
129                 scsi_req_continue(req);
130                 break;
131             case SCSI_XFER_NONE:
132                 scsi_req_dequeue(req);
133                 scsi_req_enqueue(req);
134                 break;
135             }
136         }
137         scsi_req_unref(req);
138     }
139     aio_context_release(blk_get_aio_context(s->conf.blk));
140 }
141 
142 void scsi_req_retry(SCSIRequest *req)
143 {
144     /* No need to save a reference, because scsi_dma_restart_bh just
145      * looks at the request list.  */
146     req->retry = true;
147 }
148 
149 static void scsi_dma_restart_cb(void *opaque, int running, RunState state)
150 {
151     SCSIDevice *s = opaque;
152 
153     if (!running) {
154         return;
155     }
156     if (!s->bh) {
157         AioContext *ctx = blk_get_aio_context(s->conf.blk);
158         s->bh = aio_bh_new(ctx, scsi_dma_restart_bh, s);
159         qemu_bh_schedule(s->bh);
160     }
161 }
162 
163 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
164 {
165     SCSIDevice *dev = SCSI_DEVICE(qdev);
166     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
167     SCSIDevice *d;
168     Error *local_err = NULL;
169 
170     if (dev->channel > bus->info->max_channel) {
171         error_setg(errp, "bad scsi channel id: %d", dev->channel);
172         return;
173     }
174     if (dev->id != -1 && dev->id > bus->info->max_target) {
175         error_setg(errp, "bad scsi device id: %d", dev->id);
176         return;
177     }
178     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
179         error_setg(errp, "bad scsi device lun: %d", dev->lun);
180         return;
181     }
182 
183     if (dev->id == -1) {
184         int id = -1;
185         if (dev->lun == -1) {
186             dev->lun = 0;
187         }
188         do {
189             d = scsi_device_find(bus, dev->channel, ++id, dev->lun);
190         } while (d && d->lun == dev->lun && id < bus->info->max_target);
191         if (d && d->lun == dev->lun) {
192             error_setg(errp, "no free target");
193             return;
194         }
195         dev->id = id;
196     } else if (dev->lun == -1) {
197         int lun = -1;
198         do {
199             d = scsi_device_find(bus, dev->channel, dev->id, ++lun);
200         } while (d && d->lun == lun && lun < bus->info->max_lun);
201         if (d && d->lun == lun) {
202             error_setg(errp, "no free lun");
203             return;
204         }
205         dev->lun = lun;
206     } else {
207         d = scsi_device_find(bus, dev->channel, dev->id, dev->lun);
208         assert(d);
209         if (d->lun == dev->lun && dev != d) {
210             error_setg(errp, "lun already used by '%s'", d->qdev.id);
211             return;
212         }
213     }
214 
215     QTAILQ_INIT(&dev->requests);
216     scsi_device_realize(dev, &local_err);
217     if (local_err) {
218         error_propagate(errp, local_err);
219         return;
220     }
221     dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
222             scsi_dma_restart_cb, dev);
223 }
224 
225 static void scsi_qdev_unrealize(DeviceState *qdev)
226 {
227     SCSIDevice *dev = SCSI_DEVICE(qdev);
228 
229     if (dev->vmsentry) {
230         qemu_del_vm_change_state_handler(dev->vmsentry);
231     }
232 
233     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
234 
235     scsi_device_unrealize(dev);
236 
237     blockdev_mark_auto_del(dev->conf.blk);
238 }
239 
240 /* handle legacy '-drive if=scsi,...' cmd line args */
241 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
242                                       int unit, bool removable, int bootindex,
243                                       bool share_rw,
244                                       BlockdevOnError rerror,
245                                       BlockdevOnError werror,
246                                       const char *serial, Error **errp)
247 {
248     const char *driver;
249     char *name;
250     DeviceState *dev;
251     DriveInfo *dinfo;
252 
253     if (blk_is_sg(blk)) {
254         driver = "scsi-generic";
255     } else {
256         dinfo = blk_legacy_dinfo(blk);
257         if (dinfo && dinfo->media_cd) {
258             driver = "scsi-cd";
259         } else {
260             driver = "scsi-hd";
261         }
262     }
263     dev = qdev_new(driver);
264     name = g_strdup_printf("legacy[%d]", unit);
265     object_property_add_child(OBJECT(bus), name, OBJECT(dev));
266     g_free(name);
267 
268     qdev_prop_set_uint32(dev, "scsi-id", unit);
269     if (bootindex >= 0) {
270         object_property_set_int(OBJECT(dev), "bootindex", bootindex,
271                                 &error_abort);
272     }
273     if (object_property_find(OBJECT(dev), "removable")) {
274         qdev_prop_set_bit(dev, "removable", removable);
275     }
276     if (serial && object_property_find(OBJECT(dev), "serial")) {
277         qdev_prop_set_string(dev, "serial", serial);
278     }
279     if (!qdev_prop_set_drive_err(dev, "drive", blk, errp)) {
280         object_unparent(OBJECT(dev));
281         return NULL;
282     }
283     if (!object_property_set_bool(OBJECT(dev), "share-rw", share_rw, errp)) {
284         object_unparent(OBJECT(dev));
285         return NULL;
286     }
287 
288     qdev_prop_set_enum(dev, "rerror", rerror);
289     qdev_prop_set_enum(dev, "werror", werror);
290 
291     if (!qdev_realize_and_unref(dev, &bus->qbus, errp)) {
292         object_unparent(OBJECT(dev));
293         return NULL;
294     }
295     return SCSI_DEVICE(dev);
296 }
297 
298 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
299 {
300     Location loc;
301     DriveInfo *dinfo;
302     int unit;
303 
304     loc_push_none(&loc);
305     for (unit = 0; unit <= bus->info->max_target; unit++) {
306         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
307         if (dinfo == NULL) {
308             continue;
309         }
310         qemu_opts_loc_restore(dinfo->opts);
311         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
312                                   unit, false, -1, false,
313                                   BLOCKDEV_ON_ERROR_AUTO,
314                                   BLOCKDEV_ON_ERROR_AUTO,
315                                   NULL, &error_fatal);
316     }
317     loc_pop(&loc);
318 }
319 
320 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
321 {
322     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
323     scsi_req_complete(req, CHECK_CONDITION);
324     return 0;
325 }
326 
327 static const struct SCSIReqOps reqops_invalid_field = {
328     .size         = sizeof(SCSIRequest),
329     .send_command = scsi_invalid_field
330 };
331 
332 /* SCSIReqOps implementation for invalid commands.  */
333 
334 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
335 {
336     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
337     scsi_req_complete(req, CHECK_CONDITION);
338     return 0;
339 }
340 
341 static const struct SCSIReqOps reqops_invalid_opcode = {
342     .size         = sizeof(SCSIRequest),
343     .send_command = scsi_invalid_command
344 };
345 
346 /* SCSIReqOps implementation for unit attention conditions.  */
347 
348 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
349 {
350     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
351         scsi_req_build_sense(req, req->dev->unit_attention);
352     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
353         scsi_req_build_sense(req, req->bus->unit_attention);
354     }
355     scsi_req_complete(req, CHECK_CONDITION);
356     return 0;
357 }
358 
359 static const struct SCSIReqOps reqops_unit_attention = {
360     .size         = sizeof(SCSIRequest),
361     .send_command = scsi_unit_attention
362 };
363 
364 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
365    an invalid LUN.  */
366 
367 typedef struct SCSITargetReq SCSITargetReq;
368 
369 struct SCSITargetReq {
370     SCSIRequest req;
371     int len;
372     uint8_t *buf;
373     int buf_len;
374 };
375 
376 static void store_lun(uint8_t *outbuf, int lun)
377 {
378     if (lun < 256) {
379         outbuf[1] = lun;
380         return;
381     }
382     outbuf[1] = (lun & 255);
383     outbuf[0] = (lun >> 8) | 0x40;
384 }
385 
386 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
387 {
388     BusChild *kid;
389     int i, len, n;
390     int channel, id;
391     bool found_lun0;
392 
393     if (r->req.cmd.xfer < 16) {
394         return false;
395     }
396     if (r->req.cmd.buf[2] > 2) {
397         return false;
398     }
399     channel = r->req.dev->channel;
400     id = r->req.dev->id;
401     found_lun0 = false;
402     n = 0;
403     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
404         DeviceState *qdev = kid->child;
405         SCSIDevice *dev = SCSI_DEVICE(qdev);
406 
407         if (dev->channel == channel && dev->id == id) {
408             if (dev->lun == 0) {
409                 found_lun0 = true;
410             }
411             n += 8;
412         }
413     }
414     if (!found_lun0) {
415         n += 8;
416     }
417 
418     scsi_target_alloc_buf(&r->req, n + 8);
419 
420     len = MIN(n + 8, r->req.cmd.xfer & ~7);
421     memset(r->buf, 0, len);
422     stl_be_p(&r->buf[0], n);
423     i = found_lun0 ? 8 : 16;
424     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
425         DeviceState *qdev = kid->child;
426         SCSIDevice *dev = SCSI_DEVICE(qdev);
427 
428         if (dev->channel == channel && dev->id == id) {
429             store_lun(&r->buf[i], dev->lun);
430             i += 8;
431         }
432     }
433     assert(i == n + 8);
434     r->len = len;
435     return true;
436 }
437 
438 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
439 {
440     assert(r->req.dev->lun != r->req.lun);
441 
442     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
443 
444     if (r->req.cmd.buf[1] & 0x2) {
445         /* Command support data - optional, not implemented */
446         return false;
447     }
448 
449     if (r->req.cmd.buf[1] & 0x1) {
450         /* Vital product data */
451         uint8_t page_code = r->req.cmd.buf[2];
452         r->buf[r->len++] = page_code ; /* this page */
453         r->buf[r->len++] = 0x00;
454 
455         switch (page_code) {
456         case 0x00: /* Supported page codes, mandatory */
457         {
458             int pages;
459             pages = r->len++;
460             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
461             r->buf[pages] = r->len - pages - 1; /* number of pages */
462             break;
463         }
464         default:
465             return false;
466         }
467         /* done with EVPD */
468         assert(r->len < r->buf_len);
469         r->len = MIN(r->req.cmd.xfer, r->len);
470         return true;
471     }
472 
473     /* Standard INQUIRY data */
474     if (r->req.cmd.buf[2] != 0) {
475         return false;
476     }
477 
478     /* PAGE CODE == 0 */
479     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
480     memset(r->buf, 0, r->len);
481     if (r->req.lun != 0) {
482         r->buf[0] = TYPE_NO_LUN;
483     } else {
484         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
485         r->buf[2] = 5; /* Version */
486         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
487         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
488         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
489         memcpy(&r->buf[8], "QEMU    ", 8);
490         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
491         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
492     }
493     return true;
494 }
495 
496 static size_t scsi_sense_len(SCSIRequest *req)
497 {
498     if (req->dev->type == TYPE_SCANNER)
499         return SCSI_SENSE_LEN_SCANNER;
500     else
501         return SCSI_SENSE_LEN;
502 }
503 
504 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
505 {
506     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
507     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
508 
509     if (req->lun != 0 &&
510         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
511         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
512         scsi_req_complete(req, CHECK_CONDITION);
513         return 0;
514     }
515     switch (buf[0]) {
516     case REPORT_LUNS:
517         if (!scsi_target_emulate_report_luns(r)) {
518             goto illegal_request;
519         }
520         break;
521     case INQUIRY:
522         if (!scsi_target_emulate_inquiry(r)) {
523             goto illegal_request;
524         }
525         break;
526     case REQUEST_SENSE:
527         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
528         if (req->lun != 0) {
529             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
530 
531             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
532                                           sense, fixed_sense);
533         } else {
534             r->len = scsi_device_get_sense(r->req.dev, r->buf,
535                                            MIN(req->cmd.xfer, r->buf_len),
536                                            fixed_sense);
537         }
538         if (r->req.dev->sense_is_ua) {
539             scsi_device_unit_attention_reported(req->dev);
540             r->req.dev->sense_len = 0;
541             r->req.dev->sense_is_ua = false;
542         }
543         break;
544     case TEST_UNIT_READY:
545         break;
546     default:
547         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
548         scsi_req_complete(req, CHECK_CONDITION);
549         return 0;
550     illegal_request:
551         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
552         scsi_req_complete(req, CHECK_CONDITION);
553         return 0;
554     }
555 
556     if (!r->len) {
557         scsi_req_complete(req, GOOD);
558     }
559     return r->len;
560 }
561 
562 static void scsi_target_read_data(SCSIRequest *req)
563 {
564     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
565     uint32_t n;
566 
567     n = r->len;
568     if (n > 0) {
569         r->len = 0;
570         scsi_req_data(&r->req, n);
571     } else {
572         scsi_req_complete(&r->req, GOOD);
573     }
574 }
575 
576 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
577 {
578     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
579 
580     return r->buf;
581 }
582 
583 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
584 {
585     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
586 
587     r->buf = g_malloc(len);
588     r->buf_len = len;
589 
590     return r->buf;
591 }
592 
593 static void scsi_target_free_buf(SCSIRequest *req)
594 {
595     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
596 
597     g_free(r->buf);
598 }
599 
600 static const struct SCSIReqOps reqops_target_command = {
601     .size         = sizeof(SCSITargetReq),
602     .send_command = scsi_target_send_command,
603     .read_data    = scsi_target_read_data,
604     .get_buf      = scsi_target_get_buf,
605     .free_req     = scsi_target_free_buf,
606 };
607 
608 
609 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
610                             uint32_t tag, uint32_t lun, void *hba_private)
611 {
612     SCSIRequest *req;
613     SCSIBus *bus = scsi_bus_from_device(d);
614     BusState *qbus = BUS(bus);
615     const int memset_off = offsetof(SCSIRequest, sense)
616                            + sizeof(req->sense);
617 
618     req = g_malloc(reqops->size);
619     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
620     req->refcount = 1;
621     req->bus = bus;
622     req->dev = d;
623     req->tag = tag;
624     req->lun = lun;
625     req->hba_private = hba_private;
626     req->status = -1;
627     req->ops = reqops;
628     object_ref(OBJECT(d));
629     object_ref(OBJECT(qbus->parent));
630     notifier_list_init(&req->cancel_notifiers);
631     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
632     return req;
633 }
634 
635 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
636                           uint8_t *buf, void *hba_private)
637 {
638     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
639     const SCSIReqOps *ops;
640     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
641     SCSIRequest *req;
642     SCSICommand cmd = { .len = 0 };
643     int ret;
644 
645     if ((d->unit_attention.key == UNIT_ATTENTION ||
646          bus->unit_attention.key == UNIT_ATTENTION) &&
647         (buf[0] != INQUIRY &&
648          buf[0] != REPORT_LUNS &&
649          buf[0] != GET_CONFIGURATION &&
650          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
651 
652          /*
653           * If we already have a pending unit attention condition,
654           * report this one before triggering another one.
655           */
656          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
657         ops = &reqops_unit_attention;
658     } else if (lun != d->lun ||
659                buf[0] == REPORT_LUNS ||
660                (buf[0] == REQUEST_SENSE && d->sense_len)) {
661         ops = &reqops_target_command;
662     } else {
663         ops = NULL;
664     }
665 
666     if (ops != NULL || !sc->parse_cdb) {
667         ret = scsi_req_parse_cdb(d, &cmd, buf);
668     } else {
669         ret = sc->parse_cdb(d, &cmd, buf, hba_private);
670     }
671 
672     if (ret != 0) {
673         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
674         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
675     } else {
676         assert(cmd.len != 0);
677         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
678                               cmd.mode, cmd.xfer);
679         if (cmd.lba != -1) {
680             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
681                                       cmd.lba);
682         }
683 
684         if (cmd.xfer > INT32_MAX) {
685             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
686         } else if (ops) {
687             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
688         } else {
689             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
690         }
691     }
692 
693     req->cmd = cmd;
694     req->resid = req->cmd.xfer;
695 
696     switch (buf[0]) {
697     case INQUIRY:
698         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
699         break;
700     case TEST_UNIT_READY:
701         trace_scsi_test_unit_ready(d->id, lun, tag);
702         break;
703     case REPORT_LUNS:
704         trace_scsi_report_luns(d->id, lun, tag);
705         break;
706     case REQUEST_SENSE:
707         trace_scsi_request_sense(d->id, lun, tag);
708         break;
709     default:
710         break;
711     }
712 
713     return req;
714 }
715 
716 uint8_t *scsi_req_get_buf(SCSIRequest *req)
717 {
718     return req->ops->get_buf(req);
719 }
720 
721 static void scsi_clear_unit_attention(SCSIRequest *req)
722 {
723     SCSISense *ua;
724     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
725         req->bus->unit_attention.key != UNIT_ATTENTION) {
726         return;
727     }
728 
729     /*
730      * If an INQUIRY command enters the enabled command state,
731      * the device server shall [not] clear any unit attention condition;
732      * See also MMC-6, paragraphs 6.5 and 6.6.2.
733      */
734     if (req->cmd.buf[0] == INQUIRY ||
735         req->cmd.buf[0] == GET_CONFIGURATION ||
736         req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
737         return;
738     }
739 
740     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
741         ua = &req->dev->unit_attention;
742     } else {
743         ua = &req->bus->unit_attention;
744     }
745 
746     /*
747      * If a REPORT LUNS command enters the enabled command state, [...]
748      * the device server shall clear any pending unit attention condition
749      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
750      */
751     if (req->cmd.buf[0] == REPORT_LUNS &&
752         !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
753           ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
754         return;
755     }
756 
757     *ua = SENSE_CODE(NO_SENSE);
758 }
759 
760 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
761 {
762     int ret;
763 
764     assert(len >= 14);
765     if (!req->sense_len) {
766         return 0;
767     }
768 
769     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
770 
771     /*
772      * FIXME: clearing unit attention conditions upon autosense should be done
773      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
774      * (SAM-5, 5.14).
775      *
776      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
777      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
778      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
779      */
780     if (req->dev->sense_is_ua) {
781         scsi_device_unit_attention_reported(req->dev);
782         req->dev->sense_len = 0;
783         req->dev->sense_is_ua = false;
784     }
785     return ret;
786 }
787 
788 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
789 {
790     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
791 }
792 
793 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
794 {
795     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
796                                sense.key, sense.asc, sense.ascq);
797     req->sense_len = scsi_build_sense(req->sense, sense);
798 }
799 
800 static void scsi_req_enqueue_internal(SCSIRequest *req)
801 {
802     assert(!req->enqueued);
803     scsi_req_ref(req);
804     if (req->bus->info->get_sg_list) {
805         req->sg = req->bus->info->get_sg_list(req);
806     } else {
807         req->sg = NULL;
808     }
809     req->enqueued = true;
810     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
811 }
812 
813 int32_t scsi_req_enqueue(SCSIRequest *req)
814 {
815     int32_t rc;
816 
817     assert(!req->retry);
818     scsi_req_enqueue_internal(req);
819     scsi_req_ref(req);
820     rc = req->ops->send_command(req, req->cmd.buf);
821     scsi_req_unref(req);
822     return rc;
823 }
824 
825 static void scsi_req_dequeue(SCSIRequest *req)
826 {
827     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
828     req->retry = false;
829     if (req->enqueued) {
830         QTAILQ_REMOVE(&req->dev->requests, req, next);
831         req->enqueued = false;
832         scsi_req_unref(req);
833     }
834 }
835 
836 static int scsi_get_performance_length(int num_desc, int type, int data_type)
837 {
838     /* MMC-6, paragraph 6.7.  */
839     switch (type) {
840     case 0:
841         if ((data_type & 3) == 0) {
842             /* Each descriptor is as in Table 295 - Nominal performance.  */
843             return 16 * num_desc + 8;
844         } else {
845             /* Each descriptor is as in Table 296 - Exceptions.  */
846             return 6 * num_desc + 8;
847         }
848     case 1:
849     case 4:
850     case 5:
851         return 8 * num_desc + 8;
852     case 2:
853         return 2048 * num_desc + 8;
854     case 3:
855         return 16 * num_desc + 8;
856     default:
857         return 8;
858     }
859 }
860 
861 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
862 {
863     int byte_block = (buf[2] >> 2) & 0x1;
864     int type = (buf[2] >> 4) & 0x1;
865     int xfer_unit;
866 
867     if (byte_block) {
868         if (type) {
869             xfer_unit = dev->blocksize;
870         } else {
871             xfer_unit = 512;
872         }
873     } else {
874         xfer_unit = 1;
875     }
876 
877     return xfer_unit;
878 }
879 
880 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
881 {
882     int length = buf[2] & 0x3;
883     int xfer;
884     int unit = ata_passthrough_xfer_unit(dev, buf);
885 
886     switch (length) {
887     case 0:
888     case 3: /* USB-specific.  */
889     default:
890         xfer = 0;
891         break;
892     case 1:
893         xfer = buf[3];
894         break;
895     case 2:
896         xfer = buf[4];
897         break;
898     }
899 
900     return xfer * unit;
901 }
902 
903 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
904 {
905     int extend = buf[1] & 0x1;
906     int length = buf[2] & 0x3;
907     int xfer;
908     int unit = ata_passthrough_xfer_unit(dev, buf);
909 
910     switch (length) {
911     case 0:
912     case 3: /* USB-specific.  */
913     default:
914         xfer = 0;
915         break;
916     case 1:
917         xfer = buf[4];
918         xfer |= (extend ? buf[3] << 8 : 0);
919         break;
920     case 2:
921         xfer = buf[6];
922         xfer |= (extend ? buf[5] << 8 : 0);
923         break;
924     }
925 
926     return xfer * unit;
927 }
928 
929 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
930 {
931     cmd->xfer = scsi_cdb_xfer(buf);
932     switch (buf[0]) {
933     case TEST_UNIT_READY:
934     case REWIND:
935     case START_STOP:
936     case SET_CAPACITY:
937     case WRITE_FILEMARKS:
938     case WRITE_FILEMARKS_16:
939     case SPACE:
940     case RESERVE:
941     case RELEASE:
942     case ERASE:
943     case ALLOW_MEDIUM_REMOVAL:
944     case SEEK_10:
945     case SYNCHRONIZE_CACHE:
946     case SYNCHRONIZE_CACHE_16:
947     case LOCATE_16:
948     case LOCK_UNLOCK_CACHE:
949     case SET_CD_SPEED:
950     case SET_LIMITS:
951     case WRITE_LONG_10:
952     case UPDATE_BLOCK:
953     case RESERVE_TRACK:
954     case SET_READ_AHEAD:
955     case PRE_FETCH:
956     case PRE_FETCH_16:
957     case ALLOW_OVERWRITE:
958         cmd->xfer = 0;
959         break;
960     case VERIFY_10:
961     case VERIFY_12:
962     case VERIFY_16:
963         if ((buf[1] & 2) == 0) {
964             cmd->xfer = 0;
965         } else if ((buf[1] & 4) != 0) {
966             cmd->xfer = 1;
967         }
968         cmd->xfer *= dev->blocksize;
969         break;
970     case MODE_SENSE:
971         break;
972     case WRITE_SAME_10:
973     case WRITE_SAME_16:
974         cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
975         break;
976     case READ_CAPACITY_10:
977         cmd->xfer = 8;
978         break;
979     case READ_BLOCK_LIMITS:
980         cmd->xfer = 6;
981         break;
982     case SEND_VOLUME_TAG:
983         /* GPCMD_SET_STREAMING from multimedia commands.  */
984         if (dev->type == TYPE_ROM) {
985             cmd->xfer = buf[10] | (buf[9] << 8);
986         } else {
987             cmd->xfer = buf[9] | (buf[8] << 8);
988         }
989         break;
990     case WRITE_6:
991         /* length 0 means 256 blocks */
992         if (cmd->xfer == 0) {
993             cmd->xfer = 256;
994         }
995         /* fall through */
996     case WRITE_10:
997     case WRITE_VERIFY_10:
998     case WRITE_12:
999     case WRITE_VERIFY_12:
1000     case WRITE_16:
1001     case WRITE_VERIFY_16:
1002         cmd->xfer *= dev->blocksize;
1003         break;
1004     case READ_6:
1005     case READ_REVERSE:
1006         /* length 0 means 256 blocks */
1007         if (cmd->xfer == 0) {
1008             cmd->xfer = 256;
1009         }
1010         /* fall through */
1011     case READ_10:
1012     case READ_12:
1013     case READ_16:
1014         cmd->xfer *= dev->blocksize;
1015         break;
1016     case FORMAT_UNIT:
1017         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1018          * for block devices are restricted to the header right now.  */
1019         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1020             cmd->xfer = 12;
1021         } else {
1022             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1023         }
1024         break;
1025     case INQUIRY:
1026     case RECEIVE_DIAGNOSTIC:
1027     case SEND_DIAGNOSTIC:
1028         cmd->xfer = buf[4] | (buf[3] << 8);
1029         break;
1030     case READ_CD:
1031     case READ_BUFFER:
1032     case WRITE_BUFFER:
1033     case SEND_CUE_SHEET:
1034         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1035         break;
1036     case PERSISTENT_RESERVE_OUT:
1037         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1038         break;
1039     case ERASE_12:
1040         if (dev->type == TYPE_ROM) {
1041             /* MMC command GET PERFORMANCE.  */
1042             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1043                                                     buf[10], buf[1] & 0x1f);
1044         }
1045         break;
1046     case MECHANISM_STATUS:
1047     case READ_DVD_STRUCTURE:
1048     case SEND_DVD_STRUCTURE:
1049     case MAINTENANCE_OUT:
1050     case MAINTENANCE_IN:
1051         if (dev->type == TYPE_ROM) {
1052             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1053             cmd->xfer = buf[9] | (buf[8] << 8);
1054         }
1055         break;
1056     case ATA_PASSTHROUGH_12:
1057         if (dev->type == TYPE_ROM) {
1058             /* BLANK command of MMC */
1059             cmd->xfer = 0;
1060         } else {
1061             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1062         }
1063         break;
1064     case ATA_PASSTHROUGH_16:
1065         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1066         break;
1067     }
1068     return 0;
1069 }
1070 
1071 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1072 {
1073     switch (buf[0]) {
1074     /* stream commands */
1075     case ERASE_12:
1076     case ERASE_16:
1077         cmd->xfer = 0;
1078         break;
1079     case READ_6:
1080     case READ_REVERSE:
1081     case RECOVER_BUFFERED_DATA:
1082     case WRITE_6:
1083         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1084         if (buf[1] & 0x01) { /* fixed */
1085             cmd->xfer *= dev->blocksize;
1086         }
1087         break;
1088     case READ_16:
1089     case READ_REVERSE_16:
1090     case VERIFY_16:
1091     case WRITE_16:
1092         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1093         if (buf[1] & 0x01) { /* fixed */
1094             cmd->xfer *= dev->blocksize;
1095         }
1096         break;
1097     case REWIND:
1098     case LOAD_UNLOAD:
1099         cmd->xfer = 0;
1100         break;
1101     case SPACE_16:
1102         cmd->xfer = buf[13] | (buf[12] << 8);
1103         break;
1104     case READ_POSITION:
1105         switch (buf[1] & 0x1f) /* operation code */ {
1106         case SHORT_FORM_BLOCK_ID:
1107         case SHORT_FORM_VENDOR_SPECIFIC:
1108             cmd->xfer = 20;
1109             break;
1110         case LONG_FORM:
1111             cmd->xfer = 32;
1112             break;
1113         case EXTENDED_FORM:
1114             cmd->xfer = buf[8] | (buf[7] << 8);
1115             break;
1116         default:
1117             return -1;
1118         }
1119 
1120         break;
1121     case FORMAT_UNIT:
1122         cmd->xfer = buf[4] | (buf[3] << 8);
1123         break;
1124     /* generic commands */
1125     default:
1126         return scsi_req_xfer(cmd, dev, buf);
1127     }
1128     return 0;
1129 }
1130 
1131 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1132 {
1133     switch (buf[0]) {
1134     /* medium changer commands */
1135     case EXCHANGE_MEDIUM:
1136     case INITIALIZE_ELEMENT_STATUS:
1137     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1138     case MOVE_MEDIUM:
1139     case POSITION_TO_ELEMENT:
1140         cmd->xfer = 0;
1141         break;
1142     case READ_ELEMENT_STATUS:
1143         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1144         break;
1145 
1146     /* generic commands */
1147     default:
1148         return scsi_req_xfer(cmd, dev, buf);
1149     }
1150     return 0;
1151 }
1152 
1153 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1154 {
1155     switch (buf[0]) {
1156     /* Scanner commands */
1157     case OBJECT_POSITION:
1158         cmd->xfer = 0;
1159         break;
1160     case SCAN:
1161         cmd->xfer = buf[4];
1162         break;
1163     case READ_10:
1164     case SEND:
1165     case GET_WINDOW:
1166     case SET_WINDOW:
1167         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1168         break;
1169     default:
1170         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1171         return scsi_req_xfer(cmd, dev, buf);
1172     }
1173 
1174     return 0;
1175 }
1176 
1177 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1178 {
1179     if (!cmd->xfer) {
1180         cmd->mode = SCSI_XFER_NONE;
1181         return;
1182     }
1183     switch (cmd->buf[0]) {
1184     case WRITE_6:
1185     case WRITE_10:
1186     case WRITE_VERIFY_10:
1187     case WRITE_12:
1188     case WRITE_VERIFY_12:
1189     case WRITE_16:
1190     case WRITE_VERIFY_16:
1191     case VERIFY_10:
1192     case VERIFY_12:
1193     case VERIFY_16:
1194     case COPY:
1195     case COPY_VERIFY:
1196     case COMPARE:
1197     case CHANGE_DEFINITION:
1198     case LOG_SELECT:
1199     case MODE_SELECT:
1200     case MODE_SELECT_10:
1201     case SEND_DIAGNOSTIC:
1202     case WRITE_BUFFER:
1203     case FORMAT_UNIT:
1204     case REASSIGN_BLOCKS:
1205     case SEARCH_EQUAL:
1206     case SEARCH_HIGH:
1207     case SEARCH_LOW:
1208     case UPDATE_BLOCK:
1209     case WRITE_LONG_10:
1210     case WRITE_SAME_10:
1211     case WRITE_SAME_16:
1212     case UNMAP:
1213     case SEARCH_HIGH_12:
1214     case SEARCH_EQUAL_12:
1215     case SEARCH_LOW_12:
1216     case MEDIUM_SCAN:
1217     case SEND_VOLUME_TAG:
1218     case SEND_CUE_SHEET:
1219     case SEND_DVD_STRUCTURE:
1220     case PERSISTENT_RESERVE_OUT:
1221     case MAINTENANCE_OUT:
1222     case SET_WINDOW:
1223     case SCAN:
1224         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1225          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1226          */
1227         cmd->mode = SCSI_XFER_TO_DEV;
1228         break;
1229     case ATA_PASSTHROUGH_12:
1230     case ATA_PASSTHROUGH_16:
1231         /* T_DIR */
1232         cmd->mode = (cmd->buf[2] & 0x8) ?
1233                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1234         break;
1235     default:
1236         cmd->mode = SCSI_XFER_FROM_DEV;
1237         break;
1238     }
1239 }
1240 
1241 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf)
1242 {
1243     int rc;
1244     int len;
1245 
1246     cmd->lba = -1;
1247     len = scsi_cdb_length(buf);
1248     if (len < 0) {
1249         return -1;
1250     }
1251 
1252     cmd->len = len;
1253     switch (dev->type) {
1254     case TYPE_TAPE:
1255         rc = scsi_req_stream_xfer(cmd, dev, buf);
1256         break;
1257     case TYPE_MEDIUM_CHANGER:
1258         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1259         break;
1260     case TYPE_SCANNER:
1261         rc = scsi_req_scanner_length(cmd, dev, buf);
1262         break;
1263     default:
1264         rc = scsi_req_xfer(cmd, dev, buf);
1265         break;
1266     }
1267 
1268     if (rc != 0)
1269         return rc;
1270 
1271     memcpy(cmd->buf, buf, cmd->len);
1272     scsi_cmd_xfer_mode(cmd);
1273     cmd->lba = scsi_cmd_lba(cmd);
1274     return 0;
1275 }
1276 
1277 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1278 {
1279     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1280 
1281     scsi_device_set_ua(dev, sense);
1282     if (bus->info->change) {
1283         bus->info->change(bus, dev, sense);
1284     }
1285 }
1286 
1287 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1288 {
1289     assert(req->refcount > 0);
1290     req->refcount++;
1291     return req;
1292 }
1293 
1294 void scsi_req_unref(SCSIRequest *req)
1295 {
1296     assert(req->refcount > 0);
1297     if (--req->refcount == 0) {
1298         BusState *qbus = req->dev->qdev.parent_bus;
1299         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1300 
1301         if (bus->info->free_request && req->hba_private) {
1302             bus->info->free_request(bus, req->hba_private);
1303         }
1304         if (req->ops->free_req) {
1305             req->ops->free_req(req);
1306         }
1307         object_unref(OBJECT(req->dev));
1308         object_unref(OBJECT(qbus->parent));
1309         g_free(req);
1310     }
1311 }
1312 
1313 /* Tell the device that we finished processing this chunk of I/O.  It
1314    will start the next chunk or complete the command.  */
1315 void scsi_req_continue(SCSIRequest *req)
1316 {
1317     if (req->io_canceled) {
1318         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1319         return;
1320     }
1321     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1322     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1323         req->ops->write_data(req);
1324     } else {
1325         req->ops->read_data(req);
1326     }
1327 }
1328 
1329 /* Called by the devices when data is ready for the HBA.  The HBA should
1330    start a DMA operation to read or fill the device's data buffer.
1331    Once it completes, calling scsi_req_continue will restart I/O.  */
1332 void scsi_req_data(SCSIRequest *req, int len)
1333 {
1334     uint8_t *buf;
1335     if (req->io_canceled) {
1336         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1337         return;
1338     }
1339     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1340     assert(req->cmd.mode != SCSI_XFER_NONE);
1341     if (!req->sg) {
1342         req->resid -= len;
1343         req->bus->info->transfer_data(req, len);
1344         return;
1345     }
1346 
1347     /* If the device calls scsi_req_data and the HBA specified a
1348      * scatter/gather list, the transfer has to happen in a single
1349      * step.  */
1350     assert(!req->dma_started);
1351     req->dma_started = true;
1352 
1353     buf = scsi_req_get_buf(req);
1354     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1355         req->resid = dma_buf_read(buf, len, req->sg);
1356     } else {
1357         req->resid = dma_buf_write(buf, len, req->sg);
1358     }
1359     scsi_req_continue(req);
1360 }
1361 
1362 void scsi_req_print(SCSIRequest *req)
1363 {
1364     FILE *fp = stderr;
1365     int i;
1366 
1367     fprintf(fp, "[%s id=%d] %s",
1368             req->dev->qdev.parent_bus->name,
1369             req->dev->id,
1370             scsi_command_name(req->cmd.buf[0]));
1371     for (i = 1; i < req->cmd.len; i++) {
1372         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1373     }
1374     switch (req->cmd.mode) {
1375     case SCSI_XFER_NONE:
1376         fprintf(fp, " - none\n");
1377         break;
1378     case SCSI_XFER_FROM_DEV:
1379         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1380         break;
1381     case SCSI_XFER_TO_DEV:
1382         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1383         break;
1384     default:
1385         fprintf(fp, " - Oops\n");
1386         break;
1387     }
1388 }
1389 
1390 void scsi_req_complete(SCSIRequest *req, int status)
1391 {
1392     assert(req->status == -1);
1393     req->status = status;
1394 
1395     assert(req->sense_len <= sizeof(req->sense));
1396     if (status == GOOD) {
1397         req->sense_len = 0;
1398     }
1399 
1400     if (req->sense_len) {
1401         memcpy(req->dev->sense, req->sense, req->sense_len);
1402         req->dev->sense_len = req->sense_len;
1403         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1404     } else {
1405         req->dev->sense_len = 0;
1406         req->dev->sense_is_ua = false;
1407     }
1408 
1409     /*
1410      * Unit attention state is now stored in the device's sense buffer
1411      * if the HBA didn't do autosense.  Clear the pending unit attention
1412      * flags.
1413      */
1414     scsi_clear_unit_attention(req);
1415 
1416     scsi_req_ref(req);
1417     scsi_req_dequeue(req);
1418     req->bus->info->complete(req, req->status, req->resid);
1419 
1420     /* Cancelled requests might end up being completed instead of cancelled */
1421     notifier_list_notify(&req->cancel_notifiers, req);
1422     scsi_req_unref(req);
1423 }
1424 
1425 /* Called by the devices when the request is canceled. */
1426 void scsi_req_cancel_complete(SCSIRequest *req)
1427 {
1428     assert(req->io_canceled);
1429     if (req->bus->info->cancel) {
1430         req->bus->info->cancel(req);
1431     }
1432     notifier_list_notify(&req->cancel_notifiers, req);
1433     scsi_req_unref(req);
1434 }
1435 
1436 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1437  * notifier list, the bus will be notified the requests cancellation is
1438  * completed.
1439  * */
1440 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1441 {
1442     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1443     if (notifier) {
1444         notifier_list_add(&req->cancel_notifiers, notifier);
1445     }
1446     if (req->io_canceled) {
1447         /* A blk_aio_cancel_async is pending; when it finishes,
1448          * scsi_req_cancel_complete will be called and will
1449          * call the notifier we just added.  Just wait for that.
1450          */
1451         assert(req->aiocb);
1452         return;
1453     }
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_async(req->aiocb);
1460     } else {
1461         scsi_req_cancel_complete(req);
1462     }
1463 }
1464 
1465 void scsi_req_cancel(SCSIRequest *req)
1466 {
1467     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1468     if (!req->enqueued) {
1469         return;
1470     }
1471     assert(!req->io_canceled);
1472     /* Dropped in scsi_req_cancel_complete.  */
1473     scsi_req_ref(req);
1474     scsi_req_dequeue(req);
1475     req->io_canceled = true;
1476     if (req->aiocb) {
1477         blk_aio_cancel(req->aiocb);
1478     } else {
1479         scsi_req_cancel_complete(req);
1480     }
1481 }
1482 
1483 static int scsi_ua_precedence(SCSISense sense)
1484 {
1485     if (sense.key != UNIT_ATTENTION) {
1486         return INT_MAX;
1487     }
1488     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1489         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1490         return 1;
1491     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1492         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1493         return 2;
1494     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1495         /* These two go with "all others". */
1496         ;
1497     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1498         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1499          * POWER ON OCCURRED = 1
1500          * SCSI BUS RESET OCCURRED = 2
1501          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1502          * I_T NEXUS LOSS OCCURRED = 7
1503          */
1504         return sense.ascq;
1505     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1506         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1507         return 8;
1508     }
1509     return (sense.asc << 8) | sense.ascq;
1510 }
1511 
1512 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1513 {
1514     int prec1, prec2;
1515     if (sense.key != UNIT_ATTENTION) {
1516         return;
1517     }
1518     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1519                              sense.asc, sense.ascq);
1520 
1521     /*
1522      * Override a pre-existing unit attention condition, except for a more
1523      * important reset condition.
1524     */
1525     prec1 = scsi_ua_precedence(sdev->unit_attention);
1526     prec2 = scsi_ua_precedence(sense);
1527     if (prec2 < prec1) {
1528         sdev->unit_attention = sense;
1529     }
1530 }
1531 
1532 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1533 {
1534     SCSIRequest *req;
1535 
1536     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1537     while (!QTAILQ_EMPTY(&sdev->requests)) {
1538         req = QTAILQ_FIRST(&sdev->requests);
1539         scsi_req_cancel_async(req, NULL);
1540     }
1541     blk_drain(sdev->conf.blk);
1542     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1543     scsi_device_set_ua(sdev, sense);
1544 }
1545 
1546 static char *scsibus_get_dev_path(DeviceState *dev)
1547 {
1548     SCSIDevice *d = SCSI_DEVICE(dev);
1549     DeviceState *hba = dev->parent_bus->parent;
1550     char *id;
1551     char *path;
1552 
1553     id = qdev_get_dev_path(hba);
1554     if (id) {
1555         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1556     } else {
1557         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1558     }
1559     g_free(id);
1560     return path;
1561 }
1562 
1563 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1564 {
1565     SCSIDevice *d = SCSI_DEVICE(dev);
1566     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1567                            qdev_fw_name(dev), d->id, d->lun);
1568 }
1569 
1570 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
1571 {
1572     BusChild *kid;
1573     SCSIDevice *target_dev = NULL;
1574 
1575     QTAILQ_FOREACH_REVERSE(kid, &bus->qbus.children, sibling) {
1576         DeviceState *qdev = kid->child;
1577         SCSIDevice *dev = SCSI_DEVICE(qdev);
1578 
1579         if (dev->channel == channel && dev->id == id) {
1580             if (dev->lun == lun) {
1581                 return dev;
1582             }
1583             target_dev = dev;
1584         }
1585     }
1586     return target_dev;
1587 }
1588 
1589 /* SCSI request list.  For simplicity, pv points to the whole device */
1590 
1591 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1592                              const VMStateField *field, QJSON *vmdesc)
1593 {
1594     SCSIDevice *s = pv;
1595     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1596     SCSIRequest *req;
1597 
1598     QTAILQ_FOREACH(req, &s->requests, next) {
1599         assert(!req->io_canceled);
1600         assert(req->status == -1);
1601         assert(req->enqueued);
1602 
1603         qemu_put_sbyte(f, req->retry ? 1 : 2);
1604         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1605         qemu_put_be32s(f, &req->tag);
1606         qemu_put_be32s(f, &req->lun);
1607         if (bus->info->save_request) {
1608             bus->info->save_request(f, req);
1609         }
1610         if (req->ops->save_request) {
1611             req->ops->save_request(f, req);
1612         }
1613     }
1614     qemu_put_sbyte(f, 0);
1615 
1616     return 0;
1617 }
1618 
1619 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1620                              const VMStateField *field)
1621 {
1622     SCSIDevice *s = pv;
1623     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1624     int8_t sbyte;
1625 
1626     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1627         uint8_t buf[SCSI_CMD_BUF_SIZE];
1628         uint32_t tag;
1629         uint32_t lun;
1630         SCSIRequest *req;
1631 
1632         qemu_get_buffer(f, buf, sizeof(buf));
1633         qemu_get_be32s(f, &tag);
1634         qemu_get_be32s(f, &lun);
1635         req = scsi_req_new(s, tag, lun, buf, NULL);
1636         req->retry = (sbyte == 1);
1637         if (bus->info->load_request) {
1638             req->hba_private = bus->info->load_request(f, req);
1639         }
1640         if (req->ops->load_request) {
1641             req->ops->load_request(f, req);
1642         }
1643 
1644         /* Just restart it later.  */
1645         scsi_req_enqueue_internal(req);
1646 
1647         /* At this point, the request will be kept alive by the reference
1648          * added by scsi_req_enqueue_internal, so we can release our reference.
1649          * The HBA of course will add its own reference in the load_request
1650          * callback if it needs to hold on the SCSIRequest.
1651          */
1652         scsi_req_unref(req);
1653     }
1654 
1655     return 0;
1656 }
1657 
1658 static const VMStateInfo vmstate_info_scsi_requests = {
1659     .name = "scsi-requests",
1660     .get  = get_scsi_requests,
1661     .put  = put_scsi_requests,
1662 };
1663 
1664 static bool scsi_sense_state_needed(void *opaque)
1665 {
1666     SCSIDevice *s = opaque;
1667 
1668     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1669 }
1670 
1671 static const VMStateDescription vmstate_scsi_sense_state = {
1672     .name = "SCSIDevice/sense",
1673     .version_id = 1,
1674     .minimum_version_id = 1,
1675     .needed = scsi_sense_state_needed,
1676     .fields = (VMStateField[]) {
1677         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1678                                 SCSI_SENSE_BUF_SIZE_OLD,
1679                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1680         VMSTATE_END_OF_LIST()
1681     }
1682 };
1683 
1684 const VMStateDescription vmstate_scsi_device = {
1685     .name = "SCSIDevice",
1686     .version_id = 1,
1687     .minimum_version_id = 1,
1688     .fields = (VMStateField[]) {
1689         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1690         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1691         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1692         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1693         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1694         VMSTATE_UINT32(sense_len, SCSIDevice),
1695         {
1696             .name         = "requests",
1697             .version_id   = 0,
1698             .field_exists = NULL,
1699             .size         = 0,   /* ouch */
1700             .info         = &vmstate_info_scsi_requests,
1701             .flags        = VMS_SINGLE,
1702             .offset       = 0,
1703         },
1704         VMSTATE_END_OF_LIST()
1705     },
1706     .subsections = (const VMStateDescription*[]) {
1707         &vmstate_scsi_sense_state,
1708         NULL
1709     }
1710 };
1711 
1712 static void scsi_device_class_init(ObjectClass *klass, void *data)
1713 {
1714     DeviceClass *k = DEVICE_CLASS(klass);
1715     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1716     k->bus_type  = TYPE_SCSI_BUS;
1717     k->realize   = scsi_qdev_realize;
1718     k->unrealize = scsi_qdev_unrealize;
1719     device_class_set_props(k, scsi_props);
1720 }
1721 
1722 static void scsi_dev_instance_init(Object *obj)
1723 {
1724     DeviceState *dev = DEVICE(obj);
1725     SCSIDevice *s = SCSI_DEVICE(dev);
1726 
1727     device_add_bootindex_property(obj, &s->conf.bootindex,
1728                                   "bootindex", NULL,
1729                                   &s->qdev);
1730 }
1731 
1732 static const TypeInfo scsi_device_type_info = {
1733     .name = TYPE_SCSI_DEVICE,
1734     .parent = TYPE_DEVICE,
1735     .instance_size = sizeof(SCSIDevice),
1736     .abstract = true,
1737     .class_size = sizeof(SCSIDeviceClass),
1738     .class_init = scsi_device_class_init,
1739     .instance_init = scsi_dev_instance_init,
1740 };
1741 
1742 static void scsi_register_types(void)
1743 {
1744     type_register_static(&scsi_bus_info);
1745     type_register_static(&scsi_device_type_info);
1746 }
1747 
1748 type_init(scsi_register_types)
1749