xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision c39f95dc)
1 #include "qemu/osdep.h"
2 #include "hw/hw.h"
3 #include "qapi/error.h"
4 #include "qemu/error-report.h"
5 #include "hw/scsi/scsi.h"
6 #include "scsi/constants.h"
7 #include "hw/qdev.h"
8 #include "sysemu/block-backend.h"
9 #include "sysemu/blockdev.h"
10 #include "trace.h"
11 #include "sysemu/dma.h"
12 #include "qemu/cutils.h"
13 
14 static char *scsibus_get_dev_path(DeviceState *dev);
15 static char *scsibus_get_fw_dev_path(DeviceState *dev);
16 static void scsi_req_dequeue(SCSIRequest *req);
17 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len);
18 static void scsi_target_free_buf(SCSIRequest *req);
19 
20 static Property scsi_props[] = {
21     DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
22     DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
23     DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
24     DEFINE_PROP_END_OF_LIST(),
25 };
26 
27 static void scsi_bus_class_init(ObjectClass *klass, void *data)
28 {
29     BusClass *k = BUS_CLASS(klass);
30     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
31 
32     k->get_dev_path = scsibus_get_dev_path;
33     k->get_fw_dev_path = scsibus_get_fw_dev_path;
34     hc->unplug = qdev_simple_device_unplug_cb;
35 }
36 
37 static const TypeInfo scsi_bus_info = {
38     .name = TYPE_SCSI_BUS,
39     .parent = TYPE_BUS,
40     .instance_size = sizeof(SCSIBus),
41     .class_init = scsi_bus_class_init,
42     .interfaces = (InterfaceInfo[]) {
43         { TYPE_HOTPLUG_HANDLER },
44         { }
45     }
46 };
47 static int next_scsi_bus;
48 
49 static void scsi_device_realize(SCSIDevice *s, Error **errp)
50 {
51     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
52     if (sc->realize) {
53         sc->realize(s, errp);
54     }
55 }
56 
57 int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
58                        void *hba_private)
59 {
60     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
61     int rc;
62 
63     assert(cmd->len == 0);
64     rc = scsi_req_parse_cdb(dev, cmd, buf);
65     if (bus->info->parse_cdb) {
66         rc = bus->info->parse_cdb(dev, cmd, buf, hba_private);
67     }
68     return rc;
69 }
70 
71 static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
72                                           uint8_t *buf, void *hba_private)
73 {
74     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
75     if (sc->alloc_req) {
76         return sc->alloc_req(s, tag, lun, buf, hba_private);
77     }
78 
79     return NULL;
80 }
81 
82 void scsi_device_unit_attention_reported(SCSIDevice *s)
83 {
84     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
85     if (sc->unit_attention_reported) {
86         sc->unit_attention_reported(s);
87     }
88 }
89 
90 /* Create a scsi bus, and attach devices to it.  */
91 void scsi_bus_new(SCSIBus *bus, size_t bus_size, DeviceState *host,
92                   const SCSIBusInfo *info, const char *bus_name)
93 {
94     qbus_create_inplace(bus, bus_size, TYPE_SCSI_BUS, host, bus_name);
95     bus->busnr = next_scsi_bus++;
96     bus->info = info;
97     qbus_set_bus_hotplug_handler(BUS(bus), &error_abort);
98 }
99 
100 static void scsi_dma_restart_bh(void *opaque)
101 {
102     SCSIDevice *s = opaque;
103     SCSIRequest *req, *next;
104 
105     qemu_bh_delete(s->bh);
106     s->bh = NULL;
107 
108     aio_context_acquire(blk_get_aio_context(s->conf.blk));
109     QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
110         scsi_req_ref(req);
111         if (req->retry) {
112             req->retry = false;
113             switch (req->cmd.mode) {
114             case SCSI_XFER_FROM_DEV:
115             case SCSI_XFER_TO_DEV:
116                 scsi_req_continue(req);
117                 break;
118             case SCSI_XFER_NONE:
119                 scsi_req_dequeue(req);
120                 scsi_req_enqueue(req);
121                 break;
122             }
123         }
124         scsi_req_unref(req);
125     }
126     aio_context_release(blk_get_aio_context(s->conf.blk));
127 }
128 
129 void scsi_req_retry(SCSIRequest *req)
130 {
131     /* No need to save a reference, because scsi_dma_restart_bh just
132      * looks at the request list.  */
133     req->retry = true;
134 }
135 
136 static void scsi_dma_restart_cb(void *opaque, int running, RunState state)
137 {
138     SCSIDevice *s = opaque;
139 
140     if (!running) {
141         return;
142     }
143     if (!s->bh) {
144         AioContext *ctx = blk_get_aio_context(s->conf.blk);
145         s->bh = aio_bh_new(ctx, scsi_dma_restart_bh, s);
146         qemu_bh_schedule(s->bh);
147     }
148 }
149 
150 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
151 {
152     SCSIDevice *dev = SCSI_DEVICE(qdev);
153     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
154     SCSIDevice *d;
155     Error *local_err = NULL;
156 
157     if (dev->channel > bus->info->max_channel) {
158         error_setg(errp, "bad scsi channel id: %d", dev->channel);
159         return;
160     }
161     if (dev->id != -1 && dev->id > bus->info->max_target) {
162         error_setg(errp, "bad scsi device id: %d", dev->id);
163         return;
164     }
165     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
166         error_setg(errp, "bad scsi device lun: %d", dev->lun);
167         return;
168     }
169 
170     if (dev->id == -1) {
171         int id = -1;
172         if (dev->lun == -1) {
173             dev->lun = 0;
174         }
175         do {
176             d = scsi_device_find(bus, dev->channel, ++id, dev->lun);
177         } while (d && d->lun == dev->lun && id < bus->info->max_target);
178         if (d && d->lun == dev->lun) {
179             error_setg(errp, "no free target");
180             return;
181         }
182         dev->id = id;
183     } else if (dev->lun == -1) {
184         int lun = -1;
185         do {
186             d = scsi_device_find(bus, dev->channel, dev->id, ++lun);
187         } while (d && d->lun == lun && lun < bus->info->max_lun);
188         if (d && d->lun == lun) {
189             error_setg(errp, "no free lun");
190             return;
191         }
192         dev->lun = lun;
193     } else {
194         d = scsi_device_find(bus, dev->channel, dev->id, dev->lun);
195         assert(d);
196         if (d->lun == dev->lun && dev != d) {
197             error_setg(errp, "lun already used by '%s'", d->qdev.id);
198             return;
199         }
200     }
201 
202     QTAILQ_INIT(&dev->requests);
203     scsi_device_realize(dev, &local_err);
204     if (local_err) {
205         error_propagate(errp, local_err);
206         return;
207     }
208     dev->vmsentry = qemu_add_vm_change_state_handler(scsi_dma_restart_cb,
209                                                      dev);
210 }
211 
212 static void scsi_qdev_unrealize(DeviceState *qdev, Error **errp)
213 {
214     SCSIDevice *dev = SCSI_DEVICE(qdev);
215 
216     if (dev->vmsentry) {
217         qemu_del_vm_change_state_handler(dev->vmsentry);
218     }
219 
220     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
221     blockdev_mark_auto_del(dev->conf.blk);
222 }
223 
224 /* handle legacy '-drive if=scsi,...' cmd line args */
225 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
226                                       int unit, bool removable, int bootindex,
227                                       const char *serial, Error **errp)
228 {
229     const char *driver;
230     char *name;
231     DeviceState *dev;
232     Error *err = NULL;
233 
234     driver = blk_is_sg(blk) ? "scsi-generic" : "scsi-disk";
235     dev = qdev_create(&bus->qbus, driver);
236     name = g_strdup_printf("legacy[%d]", unit);
237     object_property_add_child(OBJECT(bus), name, OBJECT(dev), NULL);
238     g_free(name);
239 
240     qdev_prop_set_uint32(dev, "scsi-id", unit);
241     if (bootindex >= 0) {
242         object_property_set_int(OBJECT(dev), bootindex, "bootindex",
243                                 &error_abort);
244     }
245     if (object_property_find(OBJECT(dev), "removable", NULL)) {
246         qdev_prop_set_bit(dev, "removable", removable);
247     }
248     if (serial && object_property_find(OBJECT(dev), "serial", NULL)) {
249         qdev_prop_set_string(dev, "serial", serial);
250     }
251     qdev_prop_set_drive(dev, "drive", blk, &err);
252     if (err) {
253         error_propagate(errp, err);
254         object_unparent(OBJECT(dev));
255         return NULL;
256     }
257     object_property_set_bool(OBJECT(dev), true, "realized", &err);
258     if (err != NULL) {
259         error_propagate(errp, err);
260         object_unparent(OBJECT(dev));
261         return NULL;
262     }
263     return SCSI_DEVICE(dev);
264 }
265 
266 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus, bool deprecated)
267 {
268     Location loc;
269     DriveInfo *dinfo;
270     int unit;
271 
272     loc_push_none(&loc);
273     for (unit = 0; unit <= bus->info->max_target; unit++) {
274         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
275         if (dinfo == NULL) {
276             continue;
277         }
278         qemu_opts_loc_restore(dinfo->opts);
279         if (deprecated) {
280             /* Handling -drive not claimed by machine initialization */
281             if (blk_get_attached_dev(blk_by_legacy_dinfo(dinfo))) {
282                 continue;       /* claimed */
283             }
284             if (!dinfo->is_default) {
285                 warn_report("bus=%d,unit=%d is deprecated with this"
286                             " machine type",
287                             bus->busnr, unit);
288             }
289         }
290         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
291                                   unit, false, -1, NULL, &error_fatal);
292     }
293     loc_pop(&loc);
294 }
295 
296 static bool is_scsi_hba_with_legacy_magic(Object *obj)
297 {
298     static const char *magic[] = {
299         "am53c974", "dc390", "esp", "lsi53c810", "lsi53c895a",
300         "megasas", "megasas-gen2", "mptsas1068", "spapr-vscsi",
301         "virtio-scsi-device",
302         NULL
303     };
304     const char *typename = object_get_typename(obj);
305     int i;
306 
307     for (i = 0; magic[i]; i++)
308         if (!strcmp(typename, magic[i])) {
309             return true;
310     }
311 
312     return false;
313 }
314 
315 static int scsi_legacy_handle_cmdline_cb(Object *obj, void *opaque)
316 {
317     SCSIBus *bus = (SCSIBus *)object_dynamic_cast(obj, TYPE_SCSI_BUS);
318 
319     if (bus && is_scsi_hba_with_legacy_magic(OBJECT(bus->qbus.parent))) {
320         scsi_bus_legacy_handle_cmdline(bus, true);
321     }
322 
323     return 0;
324 }
325 
326 void scsi_legacy_handle_cmdline(void)
327 {
328     object_child_foreach_recursive(object_get_root(),
329                                    scsi_legacy_handle_cmdline_cb, NULL);
330 }
331 
332 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
333 {
334     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
335     scsi_req_complete(req, CHECK_CONDITION);
336     return 0;
337 }
338 
339 static const struct SCSIReqOps reqops_invalid_field = {
340     .size         = sizeof(SCSIRequest),
341     .send_command = scsi_invalid_field
342 };
343 
344 /* SCSIReqOps implementation for invalid commands.  */
345 
346 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
347 {
348     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
349     scsi_req_complete(req, CHECK_CONDITION);
350     return 0;
351 }
352 
353 static const struct SCSIReqOps reqops_invalid_opcode = {
354     .size         = sizeof(SCSIRequest),
355     .send_command = scsi_invalid_command
356 };
357 
358 /* SCSIReqOps implementation for unit attention conditions.  */
359 
360 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
361 {
362     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
363         scsi_req_build_sense(req, req->dev->unit_attention);
364     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
365         scsi_req_build_sense(req, req->bus->unit_attention);
366     }
367     scsi_req_complete(req, CHECK_CONDITION);
368     return 0;
369 }
370 
371 static const struct SCSIReqOps reqops_unit_attention = {
372     .size         = sizeof(SCSIRequest),
373     .send_command = scsi_unit_attention
374 };
375 
376 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
377    an invalid LUN.  */
378 
379 typedef struct SCSITargetReq SCSITargetReq;
380 
381 struct SCSITargetReq {
382     SCSIRequest req;
383     int len;
384     uint8_t *buf;
385     int buf_len;
386 };
387 
388 static void store_lun(uint8_t *outbuf, int lun)
389 {
390     if (lun < 256) {
391         outbuf[1] = lun;
392         return;
393     }
394     outbuf[1] = (lun & 255);
395     outbuf[0] = (lun >> 8) | 0x40;
396 }
397 
398 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
399 {
400     BusChild *kid;
401     int i, len, n;
402     int channel, id;
403     bool found_lun0;
404 
405     if (r->req.cmd.xfer < 16) {
406         return false;
407     }
408     if (r->req.cmd.buf[2] > 2) {
409         return false;
410     }
411     channel = r->req.dev->channel;
412     id = r->req.dev->id;
413     found_lun0 = false;
414     n = 0;
415     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
416         DeviceState *qdev = kid->child;
417         SCSIDevice *dev = SCSI_DEVICE(qdev);
418 
419         if (dev->channel == channel && dev->id == id) {
420             if (dev->lun == 0) {
421                 found_lun0 = true;
422             }
423             n += 8;
424         }
425     }
426     if (!found_lun0) {
427         n += 8;
428     }
429 
430     scsi_target_alloc_buf(&r->req, n + 8);
431 
432     len = MIN(n + 8, r->req.cmd.xfer & ~7);
433     memset(r->buf, 0, len);
434     stl_be_p(&r->buf[0], n);
435     i = found_lun0 ? 8 : 16;
436     QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
437         DeviceState *qdev = kid->child;
438         SCSIDevice *dev = SCSI_DEVICE(qdev);
439 
440         if (dev->channel == channel && dev->id == id) {
441             store_lun(&r->buf[i], dev->lun);
442             i += 8;
443         }
444     }
445     assert(i == n + 8);
446     r->len = len;
447     return true;
448 }
449 
450 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
451 {
452     assert(r->req.dev->lun != r->req.lun);
453 
454     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
455 
456     if (r->req.cmd.buf[1] & 0x2) {
457         /* Command support data - optional, not implemented */
458         return false;
459     }
460 
461     if (r->req.cmd.buf[1] & 0x1) {
462         /* Vital product data */
463         uint8_t page_code = r->req.cmd.buf[2];
464         r->buf[r->len++] = page_code ; /* this page */
465         r->buf[r->len++] = 0x00;
466 
467         switch (page_code) {
468         case 0x00: /* Supported page codes, mandatory */
469         {
470             int pages;
471             pages = r->len++;
472             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
473             r->buf[pages] = r->len - pages - 1; /* number of pages */
474             break;
475         }
476         default:
477             return false;
478         }
479         /* done with EVPD */
480         assert(r->len < r->buf_len);
481         r->len = MIN(r->req.cmd.xfer, r->len);
482         return true;
483     }
484 
485     /* Standard INQUIRY data */
486     if (r->req.cmd.buf[2] != 0) {
487         return false;
488     }
489 
490     /* PAGE CODE == 0 */
491     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
492     memset(r->buf, 0, r->len);
493     if (r->req.lun != 0) {
494         r->buf[0] = TYPE_NO_LUN;
495     } else {
496         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
497         r->buf[2] = 5; /* Version */
498         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
499         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
500         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
501         memcpy(&r->buf[8], "QEMU    ", 8);
502         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
503         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
504     }
505     return true;
506 }
507 
508 static size_t scsi_sense_len(SCSIRequest *req)
509 {
510     if (req->dev->type == TYPE_SCANNER)
511         return SCSI_SENSE_LEN_SCANNER;
512     else
513         return SCSI_SENSE_LEN;
514 }
515 
516 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
517 {
518     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
519     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
520 
521     if (req->lun != 0 &&
522         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
523         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
524         scsi_req_complete(req, CHECK_CONDITION);
525         return 0;
526     }
527     switch (buf[0]) {
528     case REPORT_LUNS:
529         if (!scsi_target_emulate_report_luns(r)) {
530             goto illegal_request;
531         }
532         break;
533     case INQUIRY:
534         if (!scsi_target_emulate_inquiry(r)) {
535             goto illegal_request;
536         }
537         break;
538     case REQUEST_SENSE:
539         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
540         if (req->lun != 0) {
541             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
542 
543             if (fixed_sense) {
544                 r->buf[0] = 0x70;
545                 r->buf[2] = sense.key;
546                 r->buf[10] = 10;
547                 r->buf[12] = sense.asc;
548                 r->buf[13] = sense.ascq;
549                 r->len = MIN(req->cmd.xfer, SCSI_SENSE_LEN);
550             } else {
551                 r->buf[0] = 0x72;
552                 r->buf[1] = sense.key;
553                 r->buf[2] = sense.asc;
554                 r->buf[3] = sense.ascq;
555                 r->len = 8;
556             }
557         } else {
558             r->len = scsi_device_get_sense(r->req.dev, r->buf,
559                                            MIN(req->cmd.xfer, r->buf_len),
560                                            fixed_sense);
561         }
562         if (r->req.dev->sense_is_ua) {
563             scsi_device_unit_attention_reported(req->dev);
564             r->req.dev->sense_len = 0;
565             r->req.dev->sense_is_ua = false;
566         }
567         break;
568     case TEST_UNIT_READY:
569         break;
570     default:
571         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
572         scsi_req_complete(req, CHECK_CONDITION);
573         return 0;
574     illegal_request:
575         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
576         scsi_req_complete(req, CHECK_CONDITION);
577         return 0;
578     }
579 
580     if (!r->len) {
581         scsi_req_complete(req, GOOD);
582     }
583     return r->len;
584 }
585 
586 static void scsi_target_read_data(SCSIRequest *req)
587 {
588     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
589     uint32_t n;
590 
591     n = r->len;
592     if (n > 0) {
593         r->len = 0;
594         scsi_req_data(&r->req, n);
595     } else {
596         scsi_req_complete(&r->req, GOOD);
597     }
598 }
599 
600 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
601 {
602     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
603 
604     return r->buf;
605 }
606 
607 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
608 {
609     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
610 
611     r->buf = g_malloc(len);
612     r->buf_len = len;
613 
614     return r->buf;
615 }
616 
617 static void scsi_target_free_buf(SCSIRequest *req)
618 {
619     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
620 
621     g_free(r->buf);
622 }
623 
624 static const struct SCSIReqOps reqops_target_command = {
625     .size         = sizeof(SCSITargetReq),
626     .send_command = scsi_target_send_command,
627     .read_data    = scsi_target_read_data,
628     .get_buf      = scsi_target_get_buf,
629     .free_req     = scsi_target_free_buf,
630 };
631 
632 
633 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
634                             uint32_t tag, uint32_t lun, void *hba_private)
635 {
636     SCSIRequest *req;
637     SCSIBus *bus = scsi_bus_from_device(d);
638     BusState *qbus = BUS(bus);
639     const int memset_off = offsetof(SCSIRequest, sense)
640                            + sizeof(req->sense);
641 
642     req = g_malloc(reqops->size);
643     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
644     req->refcount = 1;
645     req->bus = bus;
646     req->dev = d;
647     req->tag = tag;
648     req->lun = lun;
649     req->hba_private = hba_private;
650     req->status = -1;
651     req->ops = reqops;
652     object_ref(OBJECT(d));
653     object_ref(OBJECT(qbus->parent));
654     notifier_list_init(&req->cancel_notifiers);
655     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
656     return req;
657 }
658 
659 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
660                           uint8_t *buf, void *hba_private)
661 {
662     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
663     const SCSIReqOps *ops;
664     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
665     SCSIRequest *req;
666     SCSICommand cmd = { .len = 0 };
667     int ret;
668 
669     if ((d->unit_attention.key == UNIT_ATTENTION ||
670          bus->unit_attention.key == UNIT_ATTENTION) &&
671         (buf[0] != INQUIRY &&
672          buf[0] != REPORT_LUNS &&
673          buf[0] != GET_CONFIGURATION &&
674          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
675 
676          /*
677           * If we already have a pending unit attention condition,
678           * report this one before triggering another one.
679           */
680          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
681         ops = &reqops_unit_attention;
682     } else if (lun != d->lun ||
683                buf[0] == REPORT_LUNS ||
684                (buf[0] == REQUEST_SENSE && d->sense_len)) {
685         ops = &reqops_target_command;
686     } else {
687         ops = NULL;
688     }
689 
690     if (ops != NULL || !sc->parse_cdb) {
691         ret = scsi_req_parse_cdb(d, &cmd, buf);
692     } else {
693         ret = sc->parse_cdb(d, &cmd, buf, hba_private);
694     }
695 
696     if (ret != 0) {
697         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
698         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
699     } else {
700         assert(cmd.len != 0);
701         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
702                               cmd.mode, cmd.xfer);
703         if (cmd.lba != -1) {
704             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
705                                       cmd.lba);
706         }
707 
708         if (cmd.xfer > INT32_MAX) {
709             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
710         } else if (ops) {
711             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
712         } else {
713             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
714         }
715     }
716 
717     req->cmd = cmd;
718     req->resid = req->cmd.xfer;
719 
720     switch (buf[0]) {
721     case INQUIRY:
722         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
723         break;
724     case TEST_UNIT_READY:
725         trace_scsi_test_unit_ready(d->id, lun, tag);
726         break;
727     case REPORT_LUNS:
728         trace_scsi_report_luns(d->id, lun, tag);
729         break;
730     case REQUEST_SENSE:
731         trace_scsi_request_sense(d->id, lun, tag);
732         break;
733     default:
734         break;
735     }
736 
737     return req;
738 }
739 
740 uint8_t *scsi_req_get_buf(SCSIRequest *req)
741 {
742     return req->ops->get_buf(req);
743 }
744 
745 static void scsi_clear_unit_attention(SCSIRequest *req)
746 {
747     SCSISense *ua;
748     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
749         req->bus->unit_attention.key != UNIT_ATTENTION) {
750         return;
751     }
752 
753     /*
754      * If an INQUIRY command enters the enabled command state,
755      * the device server shall [not] clear any unit attention condition;
756      * See also MMC-6, paragraphs 6.5 and 6.6.2.
757      */
758     if (req->cmd.buf[0] == INQUIRY ||
759         req->cmd.buf[0] == GET_CONFIGURATION ||
760         req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
761         return;
762     }
763 
764     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
765         ua = &req->dev->unit_attention;
766     } else {
767         ua = &req->bus->unit_attention;
768     }
769 
770     /*
771      * If a REPORT LUNS command enters the enabled command state, [...]
772      * the device server shall clear any pending unit attention condition
773      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
774      */
775     if (req->cmd.buf[0] == REPORT_LUNS &&
776         !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
777           ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
778         return;
779     }
780 
781     *ua = SENSE_CODE(NO_SENSE);
782 }
783 
784 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
785 {
786     int ret;
787 
788     assert(len >= 14);
789     if (!req->sense_len) {
790         return 0;
791     }
792 
793     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
794 
795     /*
796      * FIXME: clearing unit attention conditions upon autosense should be done
797      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
798      * (SAM-5, 5.14).
799      *
800      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
801      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
802      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
803      */
804     if (req->dev->sense_is_ua) {
805         scsi_device_unit_attention_reported(req->dev);
806         req->dev->sense_len = 0;
807         req->dev->sense_is_ua = false;
808     }
809     return ret;
810 }
811 
812 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
813 {
814     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
815 }
816 
817 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
818 {
819     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
820                                sense.key, sense.asc, sense.ascq);
821     req->sense_len = scsi_build_sense(req->sense, sense);
822 }
823 
824 static void scsi_req_enqueue_internal(SCSIRequest *req)
825 {
826     assert(!req->enqueued);
827     scsi_req_ref(req);
828     if (req->bus->info->get_sg_list) {
829         req->sg = req->bus->info->get_sg_list(req);
830     } else {
831         req->sg = NULL;
832     }
833     req->enqueued = true;
834     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
835 }
836 
837 int32_t scsi_req_enqueue(SCSIRequest *req)
838 {
839     int32_t rc;
840 
841     assert(!req->retry);
842     scsi_req_enqueue_internal(req);
843     scsi_req_ref(req);
844     rc = req->ops->send_command(req, req->cmd.buf);
845     scsi_req_unref(req);
846     return rc;
847 }
848 
849 static void scsi_req_dequeue(SCSIRequest *req)
850 {
851     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
852     req->retry = false;
853     if (req->enqueued) {
854         QTAILQ_REMOVE(&req->dev->requests, req, next);
855         req->enqueued = false;
856         scsi_req_unref(req);
857     }
858 }
859 
860 static int scsi_get_performance_length(int num_desc, int type, int data_type)
861 {
862     /* MMC-6, paragraph 6.7.  */
863     switch (type) {
864     case 0:
865         if ((data_type & 3) == 0) {
866             /* Each descriptor is as in Table 295 - Nominal performance.  */
867             return 16 * num_desc + 8;
868         } else {
869             /* Each descriptor is as in Table 296 - Exceptions.  */
870             return 6 * num_desc + 8;
871         }
872     case 1:
873     case 4:
874     case 5:
875         return 8 * num_desc + 8;
876     case 2:
877         return 2048 * num_desc + 8;
878     case 3:
879         return 16 * num_desc + 8;
880     default:
881         return 8;
882     }
883 }
884 
885 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
886 {
887     int byte_block = (buf[2] >> 2) & 0x1;
888     int type = (buf[2] >> 4) & 0x1;
889     int xfer_unit;
890 
891     if (byte_block) {
892         if (type) {
893             xfer_unit = dev->blocksize;
894         } else {
895             xfer_unit = 512;
896         }
897     } else {
898         xfer_unit = 1;
899     }
900 
901     return xfer_unit;
902 }
903 
904 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
905 {
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[3];
918         break;
919     case 2:
920         xfer = buf[4];
921         break;
922     }
923 
924     return xfer * unit;
925 }
926 
927 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
928 {
929     int extend = buf[1] & 0x1;
930     int length = buf[2] & 0x3;
931     int xfer;
932     int unit = ata_passthrough_xfer_unit(dev, buf);
933 
934     switch (length) {
935     case 0:
936     case 3: /* USB-specific.  */
937     default:
938         xfer = 0;
939         break;
940     case 1:
941         xfer = buf[4];
942         xfer |= (extend ? buf[3] << 8 : 0);
943         break;
944     case 2:
945         xfer = buf[6];
946         xfer |= (extend ? buf[5] << 8 : 0);
947         break;
948     }
949 
950     return xfer * unit;
951 }
952 
953 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
954 {
955     cmd->xfer = scsi_cdb_xfer(buf);
956     switch (buf[0]) {
957     case TEST_UNIT_READY:
958     case REWIND:
959     case START_STOP:
960     case SET_CAPACITY:
961     case WRITE_FILEMARKS:
962     case WRITE_FILEMARKS_16:
963     case SPACE:
964     case RESERVE:
965     case RELEASE:
966     case ERASE:
967     case ALLOW_MEDIUM_REMOVAL:
968     case SEEK_10:
969     case SYNCHRONIZE_CACHE:
970     case SYNCHRONIZE_CACHE_16:
971     case LOCATE_16:
972     case LOCK_UNLOCK_CACHE:
973     case SET_CD_SPEED:
974     case SET_LIMITS:
975     case WRITE_LONG_10:
976     case UPDATE_BLOCK:
977     case RESERVE_TRACK:
978     case SET_READ_AHEAD:
979     case PRE_FETCH:
980     case PRE_FETCH_16:
981     case ALLOW_OVERWRITE:
982         cmd->xfer = 0;
983         break;
984     case VERIFY_10:
985     case VERIFY_12:
986     case VERIFY_16:
987         if ((buf[1] & 2) == 0) {
988             cmd->xfer = 0;
989         } else if ((buf[1] & 4) != 0) {
990             cmd->xfer = 1;
991         }
992         cmd->xfer *= dev->blocksize;
993         break;
994     case MODE_SENSE:
995         break;
996     case WRITE_SAME_10:
997     case WRITE_SAME_16:
998         cmd->xfer = dev->blocksize;
999         break;
1000     case READ_CAPACITY_10:
1001         cmd->xfer = 8;
1002         break;
1003     case READ_BLOCK_LIMITS:
1004         cmd->xfer = 6;
1005         break;
1006     case SEND_VOLUME_TAG:
1007         /* GPCMD_SET_STREAMING from multimedia commands.  */
1008         if (dev->type == TYPE_ROM) {
1009             cmd->xfer = buf[10] | (buf[9] << 8);
1010         } else {
1011             cmd->xfer = buf[9] | (buf[8] << 8);
1012         }
1013         break;
1014     case WRITE_6:
1015         /* length 0 means 256 blocks */
1016         if (cmd->xfer == 0) {
1017             cmd->xfer = 256;
1018         }
1019         /* fall through */
1020     case WRITE_10:
1021     case WRITE_VERIFY_10:
1022     case WRITE_12:
1023     case WRITE_VERIFY_12:
1024     case WRITE_16:
1025     case WRITE_VERIFY_16:
1026         cmd->xfer *= dev->blocksize;
1027         break;
1028     case READ_6:
1029     case READ_REVERSE:
1030         /* length 0 means 256 blocks */
1031         if (cmd->xfer == 0) {
1032             cmd->xfer = 256;
1033         }
1034         /* fall through */
1035     case READ_10:
1036     case READ_12:
1037     case READ_16:
1038         cmd->xfer *= dev->blocksize;
1039         break;
1040     case FORMAT_UNIT:
1041         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1042          * for block devices are restricted to the header right now.  */
1043         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1044             cmd->xfer = 12;
1045         } else {
1046             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1047         }
1048         break;
1049     case INQUIRY:
1050     case RECEIVE_DIAGNOSTIC:
1051     case SEND_DIAGNOSTIC:
1052         cmd->xfer = buf[4] | (buf[3] << 8);
1053         break;
1054     case READ_CD:
1055     case READ_BUFFER:
1056     case WRITE_BUFFER:
1057     case SEND_CUE_SHEET:
1058         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1059         break;
1060     case PERSISTENT_RESERVE_OUT:
1061         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1062         break;
1063     case ERASE_12:
1064         if (dev->type == TYPE_ROM) {
1065             /* MMC command GET PERFORMANCE.  */
1066             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1067                                                     buf[10], buf[1] & 0x1f);
1068         }
1069         break;
1070     case MECHANISM_STATUS:
1071     case READ_DVD_STRUCTURE:
1072     case SEND_DVD_STRUCTURE:
1073     case MAINTENANCE_OUT:
1074     case MAINTENANCE_IN:
1075         if (dev->type == TYPE_ROM) {
1076             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1077             cmd->xfer = buf[9] | (buf[8] << 8);
1078         }
1079         break;
1080     case ATA_PASSTHROUGH_12:
1081         if (dev->type == TYPE_ROM) {
1082             /* BLANK command of MMC */
1083             cmd->xfer = 0;
1084         } else {
1085             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1086         }
1087         break;
1088     case ATA_PASSTHROUGH_16:
1089         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1090         break;
1091     }
1092     return 0;
1093 }
1094 
1095 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1096 {
1097     switch (buf[0]) {
1098     /* stream commands */
1099     case ERASE_12:
1100     case ERASE_16:
1101         cmd->xfer = 0;
1102         break;
1103     case READ_6:
1104     case READ_REVERSE:
1105     case RECOVER_BUFFERED_DATA:
1106     case WRITE_6:
1107         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1108         if (buf[1] & 0x01) { /* fixed */
1109             cmd->xfer *= dev->blocksize;
1110         }
1111         break;
1112     case READ_16:
1113     case READ_REVERSE_16:
1114     case VERIFY_16:
1115     case WRITE_16:
1116         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1117         if (buf[1] & 0x01) { /* fixed */
1118             cmd->xfer *= dev->blocksize;
1119         }
1120         break;
1121     case REWIND:
1122     case LOAD_UNLOAD:
1123         cmd->xfer = 0;
1124         break;
1125     case SPACE_16:
1126         cmd->xfer = buf[13] | (buf[12] << 8);
1127         break;
1128     case READ_POSITION:
1129         switch (buf[1] & 0x1f) /* operation code */ {
1130         case SHORT_FORM_BLOCK_ID:
1131         case SHORT_FORM_VENDOR_SPECIFIC:
1132             cmd->xfer = 20;
1133             break;
1134         case LONG_FORM:
1135             cmd->xfer = 32;
1136             break;
1137         case EXTENDED_FORM:
1138             cmd->xfer = buf[8] | (buf[7] << 8);
1139             break;
1140         default:
1141             return -1;
1142         }
1143 
1144         break;
1145     case FORMAT_UNIT:
1146         cmd->xfer = buf[4] | (buf[3] << 8);
1147         break;
1148     /* generic commands */
1149     default:
1150         return scsi_req_xfer(cmd, dev, buf);
1151     }
1152     return 0;
1153 }
1154 
1155 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1156 {
1157     switch (buf[0]) {
1158     /* medium changer commands */
1159     case EXCHANGE_MEDIUM:
1160     case INITIALIZE_ELEMENT_STATUS:
1161     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1162     case MOVE_MEDIUM:
1163     case POSITION_TO_ELEMENT:
1164         cmd->xfer = 0;
1165         break;
1166     case READ_ELEMENT_STATUS:
1167         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1168         break;
1169 
1170     /* generic commands */
1171     default:
1172         return scsi_req_xfer(cmd, dev, buf);
1173     }
1174     return 0;
1175 }
1176 
1177 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1178 {
1179     switch (buf[0]) {
1180     /* Scanner commands */
1181     case OBJECT_POSITION:
1182         cmd->xfer = 0;
1183         break;
1184     case SCAN:
1185         cmd->xfer = buf[4];
1186         break;
1187     case READ_10:
1188     case SEND:
1189     case GET_WINDOW:
1190     case SET_WINDOW:
1191         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1192         break;
1193     default:
1194         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1195         return scsi_req_xfer(cmd, dev, buf);
1196     }
1197 
1198     return 0;
1199 }
1200 
1201 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1202 {
1203     if (!cmd->xfer) {
1204         cmd->mode = SCSI_XFER_NONE;
1205         return;
1206     }
1207     switch (cmd->buf[0]) {
1208     case WRITE_6:
1209     case WRITE_10:
1210     case WRITE_VERIFY_10:
1211     case WRITE_12:
1212     case WRITE_VERIFY_12:
1213     case WRITE_16:
1214     case WRITE_VERIFY_16:
1215     case VERIFY_10:
1216     case VERIFY_12:
1217     case VERIFY_16:
1218     case COPY:
1219     case COPY_VERIFY:
1220     case COMPARE:
1221     case CHANGE_DEFINITION:
1222     case LOG_SELECT:
1223     case MODE_SELECT:
1224     case MODE_SELECT_10:
1225     case SEND_DIAGNOSTIC:
1226     case WRITE_BUFFER:
1227     case FORMAT_UNIT:
1228     case REASSIGN_BLOCKS:
1229     case SEARCH_EQUAL:
1230     case SEARCH_HIGH:
1231     case SEARCH_LOW:
1232     case UPDATE_BLOCK:
1233     case WRITE_LONG_10:
1234     case WRITE_SAME_10:
1235     case WRITE_SAME_16:
1236     case UNMAP:
1237     case SEARCH_HIGH_12:
1238     case SEARCH_EQUAL_12:
1239     case SEARCH_LOW_12:
1240     case MEDIUM_SCAN:
1241     case SEND_VOLUME_TAG:
1242     case SEND_CUE_SHEET:
1243     case SEND_DVD_STRUCTURE:
1244     case PERSISTENT_RESERVE_OUT:
1245     case MAINTENANCE_OUT:
1246     case SET_WINDOW:
1247     case SCAN:
1248         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1249          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1250          */
1251         cmd->mode = SCSI_XFER_TO_DEV;
1252         break;
1253     case ATA_PASSTHROUGH_12:
1254     case ATA_PASSTHROUGH_16:
1255         /* T_DIR */
1256         cmd->mode = (cmd->buf[2] & 0x8) ?
1257                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1258         break;
1259     default:
1260         cmd->mode = SCSI_XFER_FROM_DEV;
1261         break;
1262     }
1263 }
1264 
1265 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf)
1266 {
1267     int rc;
1268     int len;
1269 
1270     cmd->lba = -1;
1271     len = scsi_cdb_length(buf);
1272     if (len < 0) {
1273         return -1;
1274     }
1275 
1276     cmd->len = len;
1277     switch (dev->type) {
1278     case TYPE_TAPE:
1279         rc = scsi_req_stream_xfer(cmd, dev, buf);
1280         break;
1281     case TYPE_MEDIUM_CHANGER:
1282         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1283         break;
1284     case TYPE_SCANNER:
1285         rc = scsi_req_scanner_length(cmd, dev, buf);
1286         break;
1287     default:
1288         rc = scsi_req_xfer(cmd, dev, buf);
1289         break;
1290     }
1291 
1292     if (rc != 0)
1293         return rc;
1294 
1295     memcpy(cmd->buf, buf, cmd->len);
1296     scsi_cmd_xfer_mode(cmd);
1297     cmd->lba = scsi_cmd_lba(cmd);
1298     return 0;
1299 }
1300 
1301 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1302 {
1303     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1304 
1305     scsi_device_set_ua(dev, sense);
1306     if (bus->info->change) {
1307         bus->info->change(bus, dev, sense);
1308     }
1309 }
1310 
1311 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1312 {
1313     assert(req->refcount > 0);
1314     req->refcount++;
1315     return req;
1316 }
1317 
1318 void scsi_req_unref(SCSIRequest *req)
1319 {
1320     assert(req->refcount > 0);
1321     if (--req->refcount == 0) {
1322         BusState *qbus = req->dev->qdev.parent_bus;
1323         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1324 
1325         if (bus->info->free_request && req->hba_private) {
1326             bus->info->free_request(bus, req->hba_private);
1327         }
1328         if (req->ops->free_req) {
1329             req->ops->free_req(req);
1330         }
1331         object_unref(OBJECT(req->dev));
1332         object_unref(OBJECT(qbus->parent));
1333         g_free(req);
1334     }
1335 }
1336 
1337 /* Tell the device that we finished processing this chunk of I/O.  It
1338    will start the next chunk or complete the command.  */
1339 void scsi_req_continue(SCSIRequest *req)
1340 {
1341     if (req->io_canceled) {
1342         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1343         return;
1344     }
1345     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1346     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1347         req->ops->write_data(req);
1348     } else {
1349         req->ops->read_data(req);
1350     }
1351 }
1352 
1353 /* Called by the devices when data is ready for the HBA.  The HBA should
1354    start a DMA operation to read or fill the device's data buffer.
1355    Once it completes, calling scsi_req_continue will restart I/O.  */
1356 void scsi_req_data(SCSIRequest *req, int len)
1357 {
1358     uint8_t *buf;
1359     if (req->io_canceled) {
1360         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1361         return;
1362     }
1363     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1364     assert(req->cmd.mode != SCSI_XFER_NONE);
1365     if (!req->sg) {
1366         req->resid -= len;
1367         req->bus->info->transfer_data(req, len);
1368         return;
1369     }
1370 
1371     /* If the device calls scsi_req_data and the HBA specified a
1372      * scatter/gather list, the transfer has to happen in a single
1373      * step.  */
1374     assert(!req->dma_started);
1375     req->dma_started = true;
1376 
1377     buf = scsi_req_get_buf(req);
1378     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1379         req->resid = dma_buf_read(buf, len, req->sg);
1380     } else {
1381         req->resid = dma_buf_write(buf, len, req->sg);
1382     }
1383     scsi_req_continue(req);
1384 }
1385 
1386 void scsi_req_print(SCSIRequest *req)
1387 {
1388     FILE *fp = stderr;
1389     int i;
1390 
1391     fprintf(fp, "[%s id=%d] %s",
1392             req->dev->qdev.parent_bus->name,
1393             req->dev->id,
1394             scsi_command_name(req->cmd.buf[0]));
1395     for (i = 1; i < req->cmd.len; i++) {
1396         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1397     }
1398     switch (req->cmd.mode) {
1399     case SCSI_XFER_NONE:
1400         fprintf(fp, " - none\n");
1401         break;
1402     case SCSI_XFER_FROM_DEV:
1403         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1404         break;
1405     case SCSI_XFER_TO_DEV:
1406         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1407         break;
1408     default:
1409         fprintf(fp, " - Oops\n");
1410         break;
1411     }
1412 }
1413 
1414 void scsi_req_complete(SCSIRequest *req, int status)
1415 {
1416     assert(req->status == -1);
1417     req->status = status;
1418 
1419     assert(req->sense_len <= sizeof(req->sense));
1420     if (status == GOOD) {
1421         req->sense_len = 0;
1422     }
1423 
1424     if (req->sense_len) {
1425         memcpy(req->dev->sense, req->sense, req->sense_len);
1426         req->dev->sense_len = req->sense_len;
1427         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1428     } else {
1429         req->dev->sense_len = 0;
1430         req->dev->sense_is_ua = false;
1431     }
1432 
1433     /*
1434      * Unit attention state is now stored in the device's sense buffer
1435      * if the HBA didn't do autosense.  Clear the pending unit attention
1436      * flags.
1437      */
1438     scsi_clear_unit_attention(req);
1439 
1440     scsi_req_ref(req);
1441     scsi_req_dequeue(req);
1442     req->bus->info->complete(req, req->status, req->resid);
1443 
1444     /* Cancelled requests might end up being completed instead of cancelled */
1445     notifier_list_notify(&req->cancel_notifiers, req);
1446     scsi_req_unref(req);
1447 }
1448 
1449 /* Called by the devices when the request is canceled. */
1450 void scsi_req_cancel_complete(SCSIRequest *req)
1451 {
1452     assert(req->io_canceled);
1453     if (req->bus->info->cancel) {
1454         req->bus->info->cancel(req);
1455     }
1456     notifier_list_notify(&req->cancel_notifiers, req);
1457     scsi_req_unref(req);
1458 }
1459 
1460 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1461  * notifier list, the bus will be notified the requests cancellation is
1462  * completed.
1463  * */
1464 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1465 {
1466     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1467     if (notifier) {
1468         notifier_list_add(&req->cancel_notifiers, notifier);
1469     }
1470     if (req->io_canceled) {
1471         /* A blk_aio_cancel_async is pending; when it finishes,
1472          * scsi_req_cancel_complete will be called and will
1473          * call the notifier we just added.  Just wait for that.
1474          */
1475         assert(req->aiocb);
1476         return;
1477     }
1478     /* Dropped in scsi_req_cancel_complete.  */
1479     scsi_req_ref(req);
1480     scsi_req_dequeue(req);
1481     req->io_canceled = true;
1482     if (req->aiocb) {
1483         blk_aio_cancel_async(req->aiocb);
1484     } else {
1485         scsi_req_cancel_complete(req);
1486     }
1487 }
1488 
1489 void scsi_req_cancel(SCSIRequest *req)
1490 {
1491     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1492     if (!req->enqueued) {
1493         return;
1494     }
1495     assert(!req->io_canceled);
1496     /* Dropped in scsi_req_cancel_complete.  */
1497     scsi_req_ref(req);
1498     scsi_req_dequeue(req);
1499     req->io_canceled = true;
1500     if (req->aiocb) {
1501         blk_aio_cancel(req->aiocb);
1502     } else {
1503         scsi_req_cancel_complete(req);
1504     }
1505 }
1506 
1507 static int scsi_ua_precedence(SCSISense sense)
1508 {
1509     if (sense.key != UNIT_ATTENTION) {
1510         return INT_MAX;
1511     }
1512     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1513         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1514         return 1;
1515     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1516         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1517         return 2;
1518     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1519         /* These two go with "all others". */
1520         ;
1521     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1522         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1523          * POWER ON OCCURRED = 1
1524          * SCSI BUS RESET OCCURRED = 2
1525          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1526          * I_T NEXUS LOSS OCCURRED = 7
1527          */
1528         return sense.ascq;
1529     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1530         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1531         return 8;
1532     }
1533     return (sense.asc << 8) | sense.ascq;
1534 }
1535 
1536 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1537 {
1538     int prec1, prec2;
1539     if (sense.key != UNIT_ATTENTION) {
1540         return;
1541     }
1542     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1543                              sense.asc, sense.ascq);
1544 
1545     /*
1546      * Override a pre-existing unit attention condition, except for a more
1547      * important reset condition.
1548     */
1549     prec1 = scsi_ua_precedence(sdev->unit_attention);
1550     prec2 = scsi_ua_precedence(sense);
1551     if (prec2 < prec1) {
1552         sdev->unit_attention = sense;
1553     }
1554 }
1555 
1556 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1557 {
1558     SCSIRequest *req;
1559 
1560     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1561     while (!QTAILQ_EMPTY(&sdev->requests)) {
1562         req = QTAILQ_FIRST(&sdev->requests);
1563         scsi_req_cancel_async(req, NULL);
1564     }
1565     blk_drain(sdev->conf.blk);
1566     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1567     scsi_device_set_ua(sdev, sense);
1568 }
1569 
1570 static char *scsibus_get_dev_path(DeviceState *dev)
1571 {
1572     SCSIDevice *d = SCSI_DEVICE(dev);
1573     DeviceState *hba = dev->parent_bus->parent;
1574     char *id;
1575     char *path;
1576 
1577     id = qdev_get_dev_path(hba);
1578     if (id) {
1579         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1580     } else {
1581         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1582     }
1583     g_free(id);
1584     return path;
1585 }
1586 
1587 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1588 {
1589     SCSIDevice *d = SCSI_DEVICE(dev);
1590     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1591                            qdev_fw_name(dev), d->id, d->lun);
1592 }
1593 
1594 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
1595 {
1596     BusChild *kid;
1597     SCSIDevice *target_dev = NULL;
1598 
1599     QTAILQ_FOREACH_REVERSE(kid, &bus->qbus.children, ChildrenHead, sibling) {
1600         DeviceState *qdev = kid->child;
1601         SCSIDevice *dev = SCSI_DEVICE(qdev);
1602 
1603         if (dev->channel == channel && dev->id == id) {
1604             if (dev->lun == lun) {
1605                 return dev;
1606             }
1607             target_dev = dev;
1608         }
1609     }
1610     return target_dev;
1611 }
1612 
1613 /* SCSI request list.  For simplicity, pv points to the whole device */
1614 
1615 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1616                              VMStateField *field, QJSON *vmdesc)
1617 {
1618     SCSIDevice *s = pv;
1619     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1620     SCSIRequest *req;
1621 
1622     QTAILQ_FOREACH(req, &s->requests, next) {
1623         assert(!req->io_canceled);
1624         assert(req->status == -1);
1625         assert(req->enqueued);
1626 
1627         qemu_put_sbyte(f, req->retry ? 1 : 2);
1628         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1629         qemu_put_be32s(f, &req->tag);
1630         qemu_put_be32s(f, &req->lun);
1631         if (bus->info->save_request) {
1632             bus->info->save_request(f, req);
1633         }
1634         if (req->ops->save_request) {
1635             req->ops->save_request(f, req);
1636         }
1637     }
1638     qemu_put_sbyte(f, 0);
1639 
1640     return 0;
1641 }
1642 
1643 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1644                              VMStateField *field)
1645 {
1646     SCSIDevice *s = pv;
1647     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1648     int8_t sbyte;
1649 
1650     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1651         uint8_t buf[SCSI_CMD_BUF_SIZE];
1652         uint32_t tag;
1653         uint32_t lun;
1654         SCSIRequest *req;
1655 
1656         qemu_get_buffer(f, buf, sizeof(buf));
1657         qemu_get_be32s(f, &tag);
1658         qemu_get_be32s(f, &lun);
1659         req = scsi_req_new(s, tag, lun, buf, NULL);
1660         req->retry = (sbyte == 1);
1661         if (bus->info->load_request) {
1662             req->hba_private = bus->info->load_request(f, req);
1663         }
1664         if (req->ops->load_request) {
1665             req->ops->load_request(f, req);
1666         }
1667 
1668         /* Just restart it later.  */
1669         scsi_req_enqueue_internal(req);
1670 
1671         /* At this point, the request will be kept alive by the reference
1672          * added by scsi_req_enqueue_internal, so we can release our reference.
1673          * The HBA of course will add its own reference in the load_request
1674          * callback if it needs to hold on the SCSIRequest.
1675          */
1676         scsi_req_unref(req);
1677     }
1678 
1679     return 0;
1680 }
1681 
1682 static const VMStateInfo vmstate_info_scsi_requests = {
1683     .name = "scsi-requests",
1684     .get  = get_scsi_requests,
1685     .put  = put_scsi_requests,
1686 };
1687 
1688 static bool scsi_sense_state_needed(void *opaque)
1689 {
1690     SCSIDevice *s = opaque;
1691 
1692     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1693 }
1694 
1695 static const VMStateDescription vmstate_scsi_sense_state = {
1696     .name = "SCSIDevice/sense",
1697     .version_id = 1,
1698     .minimum_version_id = 1,
1699     .needed = scsi_sense_state_needed,
1700     .fields = (VMStateField[]) {
1701         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1702                                 SCSI_SENSE_BUF_SIZE_OLD,
1703                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1704         VMSTATE_END_OF_LIST()
1705     }
1706 };
1707 
1708 const VMStateDescription vmstate_scsi_device = {
1709     .name = "SCSIDevice",
1710     .version_id = 1,
1711     .minimum_version_id = 1,
1712     .fields = (VMStateField[]) {
1713         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1714         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1715         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1716         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1717         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1718         VMSTATE_UINT32(sense_len, SCSIDevice),
1719         {
1720             .name         = "requests",
1721             .version_id   = 0,
1722             .field_exists = NULL,
1723             .size         = 0,   /* ouch */
1724             .info         = &vmstate_info_scsi_requests,
1725             .flags        = VMS_SINGLE,
1726             .offset       = 0,
1727         },
1728         VMSTATE_END_OF_LIST()
1729     },
1730     .subsections = (const VMStateDescription*[]) {
1731         &vmstate_scsi_sense_state,
1732         NULL
1733     }
1734 };
1735 
1736 static void scsi_device_class_init(ObjectClass *klass, void *data)
1737 {
1738     DeviceClass *k = DEVICE_CLASS(klass);
1739     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1740     k->bus_type  = TYPE_SCSI_BUS;
1741     k->realize   = scsi_qdev_realize;
1742     k->unrealize = scsi_qdev_unrealize;
1743     k->props     = scsi_props;
1744 }
1745 
1746 static void scsi_dev_instance_init(Object *obj)
1747 {
1748     DeviceState *dev = DEVICE(obj);
1749     SCSIDevice *s = SCSI_DEVICE(dev);
1750 
1751     device_add_bootindex_property(obj, &s->conf.bootindex,
1752                                   "bootindex", NULL,
1753                                   &s->qdev, NULL);
1754 }
1755 
1756 static const TypeInfo scsi_device_type_info = {
1757     .name = TYPE_SCSI_DEVICE,
1758     .parent = TYPE_DEVICE,
1759     .instance_size = sizeof(SCSIDevice),
1760     .abstract = true,
1761     .class_size = sizeof(SCSIDeviceClass),
1762     .class_init = scsi_device_class_init,
1763     .instance_init = scsi_dev_instance_init,
1764 };
1765 
1766 static void scsi_register_types(void)
1767 {
1768     type_register_static(&scsi_bus_info);
1769     type_register_static(&scsi_device_type_info);
1770 }
1771 
1772 type_init(scsi_register_types)
1773