xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision e4082063)
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 "qemu/hw-version.h"
7 #include "hw/qdev-properties.h"
8 #include "hw/scsi/scsi.h"
9 #include "migration/qemu-file-types.h"
10 #include "migration/vmstate.h"
11 #include "scsi/constants.h"
12 #include "sysemu/block-backend.h"
13 #include "sysemu/blockdev.h"
14 #include "sysemu/sysemu.h"
15 #include "sysemu/runstate.h"
16 #include "trace.h"
17 #include "sysemu/dma.h"
18 #include "qemu/cutils.h"
19 
20 static char *scsibus_get_dev_path(DeviceState *dev);
21 static char *scsibus_get_fw_dev_path(DeviceState *dev);
22 static void scsi_req_dequeue(SCSIRequest *req);
23 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len);
24 static void scsi_target_free_buf(SCSIRequest *req);
25 
26 static int next_scsi_bus;
27 
28 static SCSIDevice *do_scsi_device_find(SCSIBus *bus,
29                                        int channel, int id, int lun,
30                                        bool include_unrealized)
31 {
32     BusChild *kid;
33     SCSIDevice *retval = NULL;
34 
35     QTAILQ_FOREACH_RCU(kid, &bus->qbus.children, sibling) {
36         DeviceState *qdev = kid->child;
37         SCSIDevice *dev = SCSI_DEVICE(qdev);
38 
39         if (dev->channel == channel && dev->id == id) {
40             if (dev->lun == lun) {
41                 retval = dev;
42                 break;
43             }
44 
45             /*
46              * If we don't find exact match (channel/bus/lun),
47              * we will return the first device which matches channel/bus
48              */
49 
50             if (!retval) {
51                 retval = dev;
52             }
53         }
54     }
55 
56     /*
57      * This function might run on the IO thread and we might race against
58      * main thread hot-plugging the device.
59      * We assume that as soon as .realized is set to true we can let
60      * the user access the device.
61      */
62 
63     if (retval && !include_unrealized &&
64         !qatomic_load_acquire(&retval->qdev.realized)) {
65         retval = NULL;
66     }
67 
68     return retval;
69 }
70 
71 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
72 {
73     RCU_READ_LOCK_GUARD();
74     return do_scsi_device_find(bus, channel, id, lun, false);
75 }
76 
77 SCSIDevice *scsi_device_get(SCSIBus *bus, int channel, int id, int lun)
78 {
79     SCSIDevice *d;
80     RCU_READ_LOCK_GUARD();
81     d = do_scsi_device_find(bus, channel, id, lun, false);
82     if (d) {
83         object_ref(d);
84     }
85     return d;
86 }
87 
88 static void scsi_device_realize(SCSIDevice *s, Error **errp)
89 {
90     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
91     if (sc->realize) {
92         sc->realize(s, errp);
93     }
94 }
95 
96 static void scsi_device_unrealize(SCSIDevice *s)
97 {
98     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
99     if (sc->unrealize) {
100         sc->unrealize(s);
101     }
102 }
103 
104 int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
105                        void *hba_private)
106 {
107     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
108     int rc;
109 
110     assert(cmd->len == 0);
111     rc = scsi_req_parse_cdb(dev, cmd, buf);
112     if (bus->info->parse_cdb) {
113         rc = bus->info->parse_cdb(dev, cmd, buf, hba_private);
114     }
115     return rc;
116 }
117 
118 static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
119                                           uint8_t *buf, void *hba_private)
120 {
121     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
122     if (sc->alloc_req) {
123         return sc->alloc_req(s, tag, lun, buf, hba_private);
124     }
125 
126     return NULL;
127 }
128 
129 void scsi_device_unit_attention_reported(SCSIDevice *s)
130 {
131     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
132     if (sc->unit_attention_reported) {
133         sc->unit_attention_reported(s);
134     }
135 }
136 
137 /* Create a scsi bus, and attach devices to it.  */
138 void scsi_bus_init_named(SCSIBus *bus, size_t bus_size, DeviceState *host,
139                          const SCSIBusInfo *info, const char *bus_name)
140 {
141     qbus_init(bus, bus_size, TYPE_SCSI_BUS, host, bus_name);
142     bus->busnr = next_scsi_bus++;
143     bus->info = info;
144     qbus_set_bus_hotplug_handler(BUS(bus));
145 }
146 
147 static void scsi_dma_restart_bh(void *opaque)
148 {
149     SCSIDevice *s = opaque;
150     SCSIRequest *req, *next;
151 
152     qemu_bh_delete(s->bh);
153     s->bh = NULL;
154 
155     aio_context_acquire(blk_get_aio_context(s->conf.blk));
156     QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
157         scsi_req_ref(req);
158         if (req->retry) {
159             req->retry = false;
160             switch (req->cmd.mode) {
161             case SCSI_XFER_FROM_DEV:
162             case SCSI_XFER_TO_DEV:
163                 scsi_req_continue(req);
164                 break;
165             case SCSI_XFER_NONE:
166                 scsi_req_dequeue(req);
167                 scsi_req_enqueue(req);
168                 break;
169             }
170         }
171         scsi_req_unref(req);
172     }
173     aio_context_release(blk_get_aio_context(s->conf.blk));
174     /* Drop the reference that was acquired in scsi_dma_restart_cb */
175     object_unref(OBJECT(s));
176 }
177 
178 void scsi_req_retry(SCSIRequest *req)
179 {
180     /* No need to save a reference, because scsi_dma_restart_bh just
181      * looks at the request list.  */
182     req->retry = true;
183 }
184 
185 static void scsi_dma_restart_cb(void *opaque, bool running, RunState state)
186 {
187     SCSIDevice *s = opaque;
188 
189     if (!running) {
190         return;
191     }
192     if (!s->bh) {
193         AioContext *ctx = blk_get_aio_context(s->conf.blk);
194         /* The reference is dropped in scsi_dma_restart_bh.*/
195         object_ref(OBJECT(s));
196         s->bh = aio_bh_new(ctx, scsi_dma_restart_bh, s);
197         qemu_bh_schedule(s->bh);
198     }
199 }
200 
201 static bool scsi_bus_is_address_free(SCSIBus *bus,
202 				     int channel, int target, int lun,
203 				     SCSIDevice **p_dev)
204 {
205     SCSIDevice *d;
206 
207     RCU_READ_LOCK_GUARD();
208     d = do_scsi_device_find(bus, channel, target, lun, true);
209     if (d && d->lun == lun) {
210         if (p_dev) {
211             *p_dev = d;
212         }
213         return false;
214     }
215     if (p_dev) {
216         *p_dev = NULL;
217     }
218     return true;
219 }
220 
221 static bool scsi_bus_check_address(BusState *qbus, DeviceState *qdev, Error **errp)
222 {
223     SCSIDevice *dev = SCSI_DEVICE(qdev);
224     SCSIBus *bus = SCSI_BUS(qbus);
225 
226     if (dev->channel > bus->info->max_channel) {
227         error_setg(errp, "bad scsi channel id: %d", dev->channel);
228         return false;
229     }
230     if (dev->id != -1 && dev->id > bus->info->max_target) {
231         error_setg(errp, "bad scsi device id: %d", dev->id);
232         return false;
233     }
234     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
235         error_setg(errp, "bad scsi device lun: %d", dev->lun);
236         return false;
237     }
238 
239     if (dev->id != -1 && dev->lun != -1) {
240         SCSIDevice *d;
241         if (!scsi_bus_is_address_free(bus, dev->channel, dev->id, dev->lun, &d)) {
242             error_setg(errp, "lun already used by '%s'", d->qdev.id);
243             return false;
244         }
245     }
246 
247     return true;
248 }
249 
250 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
251 {
252     SCSIDevice *dev = SCSI_DEVICE(qdev);
253     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
254     bool is_free;
255     Error *local_err = NULL;
256 
257     if (dev->id == -1) {
258         int id = -1;
259         if (dev->lun == -1) {
260             dev->lun = 0;
261         }
262         do {
263             is_free = scsi_bus_is_address_free(bus, dev->channel, ++id, dev->lun, NULL);
264         } while (!is_free && id < bus->info->max_target);
265         if (!is_free) {
266             error_setg(errp, "no free target");
267             return;
268         }
269         dev->id = id;
270     } else if (dev->lun == -1) {
271         int lun = -1;
272         do {
273             is_free = scsi_bus_is_address_free(bus, dev->channel, dev->id, ++lun, NULL);
274         } while (!is_free && lun < bus->info->max_lun);
275         if (!is_free) {
276             error_setg(errp, "no free lun");
277             return;
278         }
279         dev->lun = lun;
280     }
281 
282     QTAILQ_INIT(&dev->requests);
283     scsi_device_realize(dev, &local_err);
284     if (local_err) {
285         error_propagate(errp, local_err);
286         return;
287     }
288     dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
289             scsi_dma_restart_cb, dev);
290 }
291 
292 static void scsi_qdev_unrealize(DeviceState *qdev)
293 {
294     SCSIDevice *dev = SCSI_DEVICE(qdev);
295 
296     if (dev->vmsentry) {
297         qemu_del_vm_change_state_handler(dev->vmsentry);
298     }
299 
300     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
301 
302     scsi_device_unrealize(dev);
303 
304     blockdev_mark_auto_del(dev->conf.blk);
305 }
306 
307 /* handle legacy '-drive if=scsi,...' cmd line args */
308 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
309                                       int unit, bool removable, int bootindex,
310                                       bool share_rw,
311                                       BlockdevOnError rerror,
312                                       BlockdevOnError werror,
313                                       const char *serial, Error **errp)
314 {
315     const char *driver;
316     char *name;
317     DeviceState *dev;
318     DriveInfo *dinfo;
319 
320     if (blk_is_sg(blk)) {
321         driver = "scsi-generic";
322     } else {
323         dinfo = blk_legacy_dinfo(blk);
324         if (dinfo && dinfo->media_cd) {
325             driver = "scsi-cd";
326         } else {
327             driver = "scsi-hd";
328         }
329     }
330     dev = qdev_new(driver);
331     name = g_strdup_printf("legacy[%d]", unit);
332     object_property_add_child(OBJECT(bus), name, OBJECT(dev));
333     g_free(name);
334 
335     qdev_prop_set_uint32(dev, "scsi-id", unit);
336     if (bootindex >= 0) {
337         object_property_set_int(OBJECT(dev), "bootindex", bootindex,
338                                 &error_abort);
339     }
340     if (object_property_find(OBJECT(dev), "removable")) {
341         qdev_prop_set_bit(dev, "removable", removable);
342     }
343     if (serial && object_property_find(OBJECT(dev), "serial")) {
344         qdev_prop_set_string(dev, "serial", serial);
345     }
346     if (!qdev_prop_set_drive_err(dev, "drive", blk, errp)) {
347         object_unparent(OBJECT(dev));
348         return NULL;
349     }
350     if (!object_property_set_bool(OBJECT(dev), "share-rw", share_rw, errp)) {
351         object_unparent(OBJECT(dev));
352         return NULL;
353     }
354 
355     qdev_prop_set_enum(dev, "rerror", rerror);
356     qdev_prop_set_enum(dev, "werror", werror);
357 
358     if (!qdev_realize_and_unref(dev, &bus->qbus, errp)) {
359         object_unparent(OBJECT(dev));
360         return NULL;
361     }
362     return SCSI_DEVICE(dev);
363 }
364 
365 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
366 {
367     Location loc;
368     DriveInfo *dinfo;
369     int unit;
370 
371     loc_push_none(&loc);
372     for (unit = 0; unit <= bus->info->max_target; unit++) {
373         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
374         if (dinfo == NULL) {
375             continue;
376         }
377         qemu_opts_loc_restore(dinfo->opts);
378         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
379                                   unit, false, -1, false,
380                                   BLOCKDEV_ON_ERROR_AUTO,
381                                   BLOCKDEV_ON_ERROR_AUTO,
382                                   NULL, &error_fatal);
383     }
384     loc_pop(&loc);
385 }
386 
387 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
388 {
389     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
390     scsi_req_complete(req, CHECK_CONDITION);
391     return 0;
392 }
393 
394 static const struct SCSIReqOps reqops_invalid_field = {
395     .size         = sizeof(SCSIRequest),
396     .send_command = scsi_invalid_field
397 };
398 
399 /* SCSIReqOps implementation for invalid commands.  */
400 
401 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
402 {
403     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
404     scsi_req_complete(req, CHECK_CONDITION);
405     return 0;
406 }
407 
408 static const struct SCSIReqOps reqops_invalid_opcode = {
409     .size         = sizeof(SCSIRequest),
410     .send_command = scsi_invalid_command
411 };
412 
413 /* SCSIReqOps implementation for unit attention conditions.  */
414 
415 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
416 {
417     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
418         scsi_req_build_sense(req, req->dev->unit_attention);
419     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
420         scsi_req_build_sense(req, req->bus->unit_attention);
421     }
422     scsi_req_complete(req, CHECK_CONDITION);
423     return 0;
424 }
425 
426 static const struct SCSIReqOps reqops_unit_attention = {
427     .size         = sizeof(SCSIRequest),
428     .send_command = scsi_unit_attention
429 };
430 
431 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
432    an invalid LUN.  */
433 
434 typedef struct SCSITargetReq SCSITargetReq;
435 
436 struct SCSITargetReq {
437     SCSIRequest req;
438     int len;
439     uint8_t *buf;
440     int buf_len;
441 };
442 
443 static void store_lun(uint8_t *outbuf, int lun)
444 {
445     if (lun < 256) {
446         /* Simple logical unit addressing method*/
447         outbuf[0] = 0;
448         outbuf[1] = lun;
449     } else {
450         /* Flat space addressing method */
451         outbuf[0] = 0x40 | (lun >> 8);
452         outbuf[1] = (lun & 255);
453     }
454 }
455 
456 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
457 {
458     BusChild *kid;
459     int channel, id;
460     uint8_t tmp[8] = {0};
461     int len = 0;
462     GByteArray *buf;
463 
464     if (r->req.cmd.xfer < 16) {
465         return false;
466     }
467     if (r->req.cmd.buf[2] > 2) {
468         return false;
469     }
470 
471     /* reserve space for 63 LUNs*/
472     buf = g_byte_array_sized_new(512);
473 
474     channel = r->req.dev->channel;
475     id = r->req.dev->id;
476 
477     /* add size (will be updated later to correct value */
478     g_byte_array_append(buf, tmp, 8);
479     len += 8;
480 
481     /* add LUN0 */
482     g_byte_array_append(buf, tmp, 8);
483     len += 8;
484 
485     WITH_RCU_READ_LOCK_GUARD() {
486         QTAILQ_FOREACH_RCU(kid, &r->req.bus->qbus.children, sibling) {
487             DeviceState *qdev = kid->child;
488             SCSIDevice *dev = SCSI_DEVICE(qdev);
489 
490             if (dev->channel == channel && dev->id == id && dev->lun != 0) {
491                 store_lun(tmp, dev->lun);
492                 g_byte_array_append(buf, tmp, 8);
493                 len += 8;
494             }
495         }
496     }
497 
498     r->buf_len = len;
499     r->buf = g_byte_array_free(buf, FALSE);
500     r->len = MIN(len, r->req.cmd.xfer & ~7);
501 
502     /* store the LUN list length */
503     stl_be_p(&r->buf[0], len - 8);
504     return true;
505 }
506 
507 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
508 {
509     assert(r->req.dev->lun != r->req.lun);
510 
511     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
512 
513     if (r->req.cmd.buf[1] & 0x2) {
514         /* Command support data - optional, not implemented */
515         return false;
516     }
517 
518     if (r->req.cmd.buf[1] & 0x1) {
519         /* Vital product data */
520         uint8_t page_code = r->req.cmd.buf[2];
521         r->buf[r->len++] = page_code ; /* this page */
522         r->buf[r->len++] = 0x00;
523 
524         switch (page_code) {
525         case 0x00: /* Supported page codes, mandatory */
526         {
527             int pages;
528             pages = r->len++;
529             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
530             r->buf[pages] = r->len - pages - 1; /* number of pages */
531             break;
532         }
533         default:
534             return false;
535         }
536         /* done with EVPD */
537         assert(r->len < r->buf_len);
538         r->len = MIN(r->req.cmd.xfer, r->len);
539         return true;
540     }
541 
542     /* Standard INQUIRY data */
543     if (r->req.cmd.buf[2] != 0) {
544         return false;
545     }
546 
547     /* PAGE CODE == 0 */
548     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
549     memset(r->buf, 0, r->len);
550     if (r->req.lun != 0) {
551         r->buf[0] = TYPE_NO_LUN;
552     } else {
553         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
554         r->buf[2] = 5; /* Version */
555         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
556         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
557         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
558         memcpy(&r->buf[8], "QEMU    ", 8);
559         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
560         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
561     }
562     return true;
563 }
564 
565 static size_t scsi_sense_len(SCSIRequest *req)
566 {
567     if (req->dev->type == TYPE_SCANNER)
568         return SCSI_SENSE_LEN_SCANNER;
569     else
570         return SCSI_SENSE_LEN;
571 }
572 
573 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
574 {
575     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
576     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
577 
578     if (req->lun != 0 &&
579         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
580         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
581         scsi_req_complete(req, CHECK_CONDITION);
582         return 0;
583     }
584     switch (buf[0]) {
585     case REPORT_LUNS:
586         if (!scsi_target_emulate_report_luns(r)) {
587             goto illegal_request;
588         }
589         break;
590     case INQUIRY:
591         if (!scsi_target_emulate_inquiry(r)) {
592             goto illegal_request;
593         }
594         break;
595     case REQUEST_SENSE:
596         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
597         if (req->lun != 0) {
598             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
599 
600             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
601                                           sense, fixed_sense);
602         } else {
603             r->len = scsi_device_get_sense(r->req.dev, r->buf,
604                                            MIN(req->cmd.xfer, r->buf_len),
605                                            fixed_sense);
606         }
607         if (r->req.dev->sense_is_ua) {
608             scsi_device_unit_attention_reported(req->dev);
609             r->req.dev->sense_len = 0;
610             r->req.dev->sense_is_ua = false;
611         }
612         break;
613     case TEST_UNIT_READY:
614         break;
615     default:
616         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
617         scsi_req_complete(req, CHECK_CONDITION);
618         return 0;
619     illegal_request:
620         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
621         scsi_req_complete(req, CHECK_CONDITION);
622         return 0;
623     }
624 
625     if (!r->len) {
626         scsi_req_complete(req, GOOD);
627     }
628     return r->len;
629 }
630 
631 static void scsi_target_read_data(SCSIRequest *req)
632 {
633     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
634     uint32_t n;
635 
636     n = r->len;
637     if (n > 0) {
638         r->len = 0;
639         scsi_req_data(&r->req, n);
640     } else {
641         scsi_req_complete(&r->req, GOOD);
642     }
643 }
644 
645 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
646 {
647     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
648 
649     return r->buf;
650 }
651 
652 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
653 {
654     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
655 
656     r->buf = g_malloc(len);
657     r->buf_len = len;
658 
659     return r->buf;
660 }
661 
662 static void scsi_target_free_buf(SCSIRequest *req)
663 {
664     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
665 
666     g_free(r->buf);
667 }
668 
669 static const struct SCSIReqOps reqops_target_command = {
670     .size         = sizeof(SCSITargetReq),
671     .send_command = scsi_target_send_command,
672     .read_data    = scsi_target_read_data,
673     .get_buf      = scsi_target_get_buf,
674     .free_req     = scsi_target_free_buf,
675 };
676 
677 
678 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
679                             uint32_t tag, uint32_t lun, void *hba_private)
680 {
681     SCSIRequest *req;
682     SCSIBus *bus = scsi_bus_from_device(d);
683     BusState *qbus = BUS(bus);
684     const int memset_off = offsetof(SCSIRequest, sense)
685                            + sizeof(req->sense);
686 
687     req = g_malloc(reqops->size);
688     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
689     req->refcount = 1;
690     req->bus = bus;
691     req->dev = d;
692     req->tag = tag;
693     req->lun = lun;
694     req->hba_private = hba_private;
695     req->status = -1;
696     req->host_status = -1;
697     req->ops = reqops;
698     object_ref(OBJECT(d));
699     object_ref(OBJECT(qbus->parent));
700     notifier_list_init(&req->cancel_notifiers);
701     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
702     return req;
703 }
704 
705 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
706                           uint8_t *buf, void *hba_private)
707 {
708     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
709     const SCSIReqOps *ops;
710     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
711     SCSIRequest *req;
712     SCSICommand cmd = { .len = 0 };
713     int ret;
714 
715     if ((d->unit_attention.key == UNIT_ATTENTION ||
716          bus->unit_attention.key == UNIT_ATTENTION) &&
717         (buf[0] != INQUIRY &&
718          buf[0] != REPORT_LUNS &&
719          buf[0] != GET_CONFIGURATION &&
720          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
721 
722          /*
723           * If we already have a pending unit attention condition,
724           * report this one before triggering another one.
725           */
726          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
727         ops = &reqops_unit_attention;
728     } else if (lun != d->lun ||
729                buf[0] == REPORT_LUNS ||
730                (buf[0] == REQUEST_SENSE && d->sense_len)) {
731         ops = &reqops_target_command;
732     } else {
733         ops = NULL;
734     }
735 
736     if (ops != NULL || !sc->parse_cdb) {
737         ret = scsi_req_parse_cdb(d, &cmd, buf);
738     } else {
739         ret = sc->parse_cdb(d, &cmd, buf, hba_private);
740     }
741 
742     if (ret != 0) {
743         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
744         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
745     } else {
746         assert(cmd.len != 0);
747         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
748                               cmd.mode, cmd.xfer);
749         if (cmd.lba != -1) {
750             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
751                                       cmd.lba);
752         }
753 
754         if (cmd.xfer > INT32_MAX) {
755             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
756         } else if (ops) {
757             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
758         } else {
759             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
760         }
761     }
762 
763     req->cmd = cmd;
764     req->residual = req->cmd.xfer;
765 
766     switch (buf[0]) {
767     case INQUIRY:
768         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
769         break;
770     case TEST_UNIT_READY:
771         trace_scsi_test_unit_ready(d->id, lun, tag);
772         break;
773     case REPORT_LUNS:
774         trace_scsi_report_luns(d->id, lun, tag);
775         break;
776     case REQUEST_SENSE:
777         trace_scsi_request_sense(d->id, lun, tag);
778         break;
779     default:
780         break;
781     }
782 
783     return req;
784 }
785 
786 uint8_t *scsi_req_get_buf(SCSIRequest *req)
787 {
788     return req->ops->get_buf(req);
789 }
790 
791 static void scsi_clear_unit_attention(SCSIRequest *req)
792 {
793     SCSISense *ua;
794     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
795         req->bus->unit_attention.key != UNIT_ATTENTION) {
796         return;
797     }
798 
799     /*
800      * If an INQUIRY command enters the enabled command state,
801      * the device server shall [not] clear any unit attention condition;
802      * See also MMC-6, paragraphs 6.5 and 6.6.2.
803      */
804     if (req->cmd.buf[0] == INQUIRY ||
805         req->cmd.buf[0] == GET_CONFIGURATION ||
806         req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
807         return;
808     }
809 
810     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
811         ua = &req->dev->unit_attention;
812     } else {
813         ua = &req->bus->unit_attention;
814     }
815 
816     /*
817      * If a REPORT LUNS command enters the enabled command state, [...]
818      * the device server shall clear any pending unit attention condition
819      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
820      */
821     if (req->cmd.buf[0] == REPORT_LUNS &&
822         !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
823           ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
824         return;
825     }
826 
827     *ua = SENSE_CODE(NO_SENSE);
828 }
829 
830 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
831 {
832     int ret;
833 
834     assert(len >= 14);
835     if (!req->sense_len) {
836         return 0;
837     }
838 
839     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
840 
841     /*
842      * FIXME: clearing unit attention conditions upon autosense should be done
843      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
844      * (SAM-5, 5.14).
845      *
846      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
847      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
848      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
849      */
850     if (req->dev->sense_is_ua) {
851         scsi_device_unit_attention_reported(req->dev);
852         req->dev->sense_len = 0;
853         req->dev->sense_is_ua = false;
854     }
855     return ret;
856 }
857 
858 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
859 {
860     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
861 }
862 
863 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
864 {
865     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
866                                sense.key, sense.asc, sense.ascq);
867     req->sense_len = scsi_build_sense(req->sense, sense);
868 }
869 
870 static void scsi_req_enqueue_internal(SCSIRequest *req)
871 {
872     assert(!req->enqueued);
873     scsi_req_ref(req);
874     if (req->bus->info->get_sg_list) {
875         req->sg = req->bus->info->get_sg_list(req);
876     } else {
877         req->sg = NULL;
878     }
879     req->enqueued = true;
880     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
881 }
882 
883 int32_t scsi_req_enqueue(SCSIRequest *req)
884 {
885     int32_t rc;
886 
887     assert(!req->retry);
888     scsi_req_enqueue_internal(req);
889     scsi_req_ref(req);
890     rc = req->ops->send_command(req, req->cmd.buf);
891     scsi_req_unref(req);
892     return rc;
893 }
894 
895 static void scsi_req_dequeue(SCSIRequest *req)
896 {
897     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
898     req->retry = false;
899     if (req->enqueued) {
900         QTAILQ_REMOVE(&req->dev->requests, req, next);
901         req->enqueued = false;
902         scsi_req_unref(req);
903     }
904 }
905 
906 static int scsi_get_performance_length(int num_desc, int type, int data_type)
907 {
908     /* MMC-6, paragraph 6.7.  */
909     switch (type) {
910     case 0:
911         if ((data_type & 3) == 0) {
912             /* Each descriptor is as in Table 295 - Nominal performance.  */
913             return 16 * num_desc + 8;
914         } else {
915             /* Each descriptor is as in Table 296 - Exceptions.  */
916             return 6 * num_desc + 8;
917         }
918     case 1:
919     case 4:
920     case 5:
921         return 8 * num_desc + 8;
922     case 2:
923         return 2048 * num_desc + 8;
924     case 3:
925         return 16 * num_desc + 8;
926     default:
927         return 8;
928     }
929 }
930 
931 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
932 {
933     int byte_block = (buf[2] >> 2) & 0x1;
934     int type = (buf[2] >> 4) & 0x1;
935     int xfer_unit;
936 
937     if (byte_block) {
938         if (type) {
939             xfer_unit = dev->blocksize;
940         } else {
941             xfer_unit = 512;
942         }
943     } else {
944         xfer_unit = 1;
945     }
946 
947     return xfer_unit;
948 }
949 
950 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
951 {
952     int length = buf[2] & 0x3;
953     int xfer;
954     int unit = ata_passthrough_xfer_unit(dev, buf);
955 
956     switch (length) {
957     case 0:
958     case 3: /* USB-specific.  */
959     default:
960         xfer = 0;
961         break;
962     case 1:
963         xfer = buf[3];
964         break;
965     case 2:
966         xfer = buf[4];
967         break;
968     }
969 
970     return xfer * unit;
971 }
972 
973 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
974 {
975     int extend = buf[1] & 0x1;
976     int length = buf[2] & 0x3;
977     int xfer;
978     int unit = ata_passthrough_xfer_unit(dev, buf);
979 
980     switch (length) {
981     case 0:
982     case 3: /* USB-specific.  */
983     default:
984         xfer = 0;
985         break;
986     case 1:
987         xfer = buf[4];
988         xfer |= (extend ? buf[3] << 8 : 0);
989         break;
990     case 2:
991         xfer = buf[6];
992         xfer |= (extend ? buf[5] << 8 : 0);
993         break;
994     }
995 
996     return xfer * unit;
997 }
998 
999 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1000 {
1001     cmd->xfer = scsi_cdb_xfer(buf);
1002     switch (buf[0]) {
1003     case TEST_UNIT_READY:
1004     case REWIND:
1005     case START_STOP:
1006     case SET_CAPACITY:
1007     case WRITE_FILEMARKS:
1008     case WRITE_FILEMARKS_16:
1009     case SPACE:
1010     case RESERVE:
1011     case RELEASE:
1012     case ERASE:
1013     case ALLOW_MEDIUM_REMOVAL:
1014     case SEEK_10:
1015     case SYNCHRONIZE_CACHE:
1016     case SYNCHRONIZE_CACHE_16:
1017     case LOCATE_16:
1018     case LOCK_UNLOCK_CACHE:
1019     case SET_CD_SPEED:
1020     case SET_LIMITS:
1021     case WRITE_LONG_10:
1022     case UPDATE_BLOCK:
1023     case RESERVE_TRACK:
1024     case SET_READ_AHEAD:
1025     case PRE_FETCH:
1026     case PRE_FETCH_16:
1027     case ALLOW_OVERWRITE:
1028         cmd->xfer = 0;
1029         break;
1030     case VERIFY_10:
1031     case VERIFY_12:
1032     case VERIFY_16:
1033         if ((buf[1] & 2) == 0) {
1034             cmd->xfer = 0;
1035         } else if ((buf[1] & 4) != 0) {
1036             cmd->xfer = 1;
1037         }
1038         cmd->xfer *= dev->blocksize;
1039         break;
1040     case MODE_SENSE:
1041         break;
1042     case WRITE_SAME_10:
1043     case WRITE_SAME_16:
1044         cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
1045         break;
1046     case READ_CAPACITY_10:
1047         cmd->xfer = 8;
1048         break;
1049     case READ_BLOCK_LIMITS:
1050         cmd->xfer = 6;
1051         break;
1052     case SEND_VOLUME_TAG:
1053         /* GPCMD_SET_STREAMING from multimedia commands.  */
1054         if (dev->type == TYPE_ROM) {
1055             cmd->xfer = buf[10] | (buf[9] << 8);
1056         } else {
1057             cmd->xfer = buf[9] | (buf[8] << 8);
1058         }
1059         break;
1060     case WRITE_6:
1061         /* length 0 means 256 blocks */
1062         if (cmd->xfer == 0) {
1063             cmd->xfer = 256;
1064         }
1065         /* fall through */
1066     case WRITE_10:
1067     case WRITE_VERIFY_10:
1068     case WRITE_12:
1069     case WRITE_VERIFY_12:
1070     case WRITE_16:
1071     case WRITE_VERIFY_16:
1072         cmd->xfer *= dev->blocksize;
1073         break;
1074     case READ_6:
1075     case READ_REVERSE:
1076         /* length 0 means 256 blocks */
1077         if (cmd->xfer == 0) {
1078             cmd->xfer = 256;
1079         }
1080         /* fall through */
1081     case READ_10:
1082     case READ_12:
1083     case READ_16:
1084         cmd->xfer *= dev->blocksize;
1085         break;
1086     case FORMAT_UNIT:
1087         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1088          * for block devices are restricted to the header right now.  */
1089         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1090             cmd->xfer = 12;
1091         } else {
1092             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1093         }
1094         break;
1095     case INQUIRY:
1096     case RECEIVE_DIAGNOSTIC:
1097     case SEND_DIAGNOSTIC:
1098         cmd->xfer = buf[4] | (buf[3] << 8);
1099         break;
1100     case READ_CD:
1101     case READ_BUFFER:
1102     case WRITE_BUFFER:
1103     case SEND_CUE_SHEET:
1104         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1105         break;
1106     case PERSISTENT_RESERVE_OUT:
1107         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1108         break;
1109     case ERASE_12:
1110         if (dev->type == TYPE_ROM) {
1111             /* MMC command GET PERFORMANCE.  */
1112             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1113                                                     buf[10], buf[1] & 0x1f);
1114         }
1115         break;
1116     case MECHANISM_STATUS:
1117     case READ_DVD_STRUCTURE:
1118     case SEND_DVD_STRUCTURE:
1119     case MAINTENANCE_OUT:
1120     case MAINTENANCE_IN:
1121         if (dev->type == TYPE_ROM) {
1122             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1123             cmd->xfer = buf[9] | (buf[8] << 8);
1124         }
1125         break;
1126     case ATA_PASSTHROUGH_12:
1127         if (dev->type == TYPE_ROM) {
1128             /* BLANK command of MMC */
1129             cmd->xfer = 0;
1130         } else {
1131             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1132         }
1133         break;
1134     case ATA_PASSTHROUGH_16:
1135         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1136         break;
1137     }
1138     return 0;
1139 }
1140 
1141 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1142 {
1143     switch (buf[0]) {
1144     /* stream commands */
1145     case ERASE_12:
1146     case ERASE_16:
1147         cmd->xfer = 0;
1148         break;
1149     case READ_6:
1150     case READ_REVERSE:
1151     case RECOVER_BUFFERED_DATA:
1152     case WRITE_6:
1153         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1154         if (buf[1] & 0x01) { /* fixed */
1155             cmd->xfer *= dev->blocksize;
1156         }
1157         break;
1158     case READ_16:
1159     case READ_REVERSE_16:
1160     case VERIFY_16:
1161     case WRITE_16:
1162         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1163         if (buf[1] & 0x01) { /* fixed */
1164             cmd->xfer *= dev->blocksize;
1165         }
1166         break;
1167     case REWIND:
1168     case LOAD_UNLOAD:
1169         cmd->xfer = 0;
1170         break;
1171     case SPACE_16:
1172         cmd->xfer = buf[13] | (buf[12] << 8);
1173         break;
1174     case READ_POSITION:
1175         switch (buf[1] & 0x1f) /* operation code */ {
1176         case SHORT_FORM_BLOCK_ID:
1177         case SHORT_FORM_VENDOR_SPECIFIC:
1178             cmd->xfer = 20;
1179             break;
1180         case LONG_FORM:
1181             cmd->xfer = 32;
1182             break;
1183         case EXTENDED_FORM:
1184             cmd->xfer = buf[8] | (buf[7] << 8);
1185             break;
1186         default:
1187             return -1;
1188         }
1189 
1190         break;
1191     case FORMAT_UNIT:
1192         cmd->xfer = buf[4] | (buf[3] << 8);
1193         break;
1194     /* generic commands */
1195     default:
1196         return scsi_req_xfer(cmd, dev, buf);
1197     }
1198     return 0;
1199 }
1200 
1201 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1202 {
1203     switch (buf[0]) {
1204     /* medium changer commands */
1205     case EXCHANGE_MEDIUM:
1206     case INITIALIZE_ELEMENT_STATUS:
1207     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1208     case MOVE_MEDIUM:
1209     case POSITION_TO_ELEMENT:
1210         cmd->xfer = 0;
1211         break;
1212     case READ_ELEMENT_STATUS:
1213         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1214         break;
1215 
1216     /* generic commands */
1217     default:
1218         return scsi_req_xfer(cmd, dev, buf);
1219     }
1220     return 0;
1221 }
1222 
1223 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1224 {
1225     switch (buf[0]) {
1226     /* Scanner commands */
1227     case OBJECT_POSITION:
1228         cmd->xfer = 0;
1229         break;
1230     case SCAN:
1231         cmd->xfer = buf[4];
1232         break;
1233     case READ_10:
1234     case SEND:
1235     case GET_WINDOW:
1236     case SET_WINDOW:
1237         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1238         break;
1239     default:
1240         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1241         return scsi_req_xfer(cmd, dev, buf);
1242     }
1243 
1244     return 0;
1245 }
1246 
1247 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1248 {
1249     if (!cmd->xfer) {
1250         cmd->mode = SCSI_XFER_NONE;
1251         return;
1252     }
1253     switch (cmd->buf[0]) {
1254     case WRITE_6:
1255     case WRITE_10:
1256     case WRITE_VERIFY_10:
1257     case WRITE_12:
1258     case WRITE_VERIFY_12:
1259     case WRITE_16:
1260     case WRITE_VERIFY_16:
1261     case VERIFY_10:
1262     case VERIFY_12:
1263     case VERIFY_16:
1264     case COPY:
1265     case COPY_VERIFY:
1266     case COMPARE:
1267     case CHANGE_DEFINITION:
1268     case LOG_SELECT:
1269     case MODE_SELECT:
1270     case MODE_SELECT_10:
1271     case SEND_DIAGNOSTIC:
1272     case WRITE_BUFFER:
1273     case FORMAT_UNIT:
1274     case REASSIGN_BLOCKS:
1275     case SEARCH_EQUAL:
1276     case SEARCH_HIGH:
1277     case SEARCH_LOW:
1278     case UPDATE_BLOCK:
1279     case WRITE_LONG_10:
1280     case WRITE_SAME_10:
1281     case WRITE_SAME_16:
1282     case UNMAP:
1283     case SEARCH_HIGH_12:
1284     case SEARCH_EQUAL_12:
1285     case SEARCH_LOW_12:
1286     case MEDIUM_SCAN:
1287     case SEND_VOLUME_TAG:
1288     case SEND_CUE_SHEET:
1289     case SEND_DVD_STRUCTURE:
1290     case PERSISTENT_RESERVE_OUT:
1291     case MAINTENANCE_OUT:
1292     case SET_WINDOW:
1293     case SCAN:
1294         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1295          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1296          */
1297         cmd->mode = SCSI_XFER_TO_DEV;
1298         break;
1299     case ATA_PASSTHROUGH_12:
1300     case ATA_PASSTHROUGH_16:
1301         /* T_DIR */
1302         cmd->mode = (cmd->buf[2] & 0x8) ?
1303                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1304         break;
1305     default:
1306         cmd->mode = SCSI_XFER_FROM_DEV;
1307         break;
1308     }
1309 }
1310 
1311 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf)
1312 {
1313     int rc;
1314     int len;
1315 
1316     cmd->lba = -1;
1317     len = scsi_cdb_length(buf);
1318     if (len < 0) {
1319         return -1;
1320     }
1321 
1322     cmd->len = len;
1323     switch (dev->type) {
1324     case TYPE_TAPE:
1325         rc = scsi_req_stream_xfer(cmd, dev, buf);
1326         break;
1327     case TYPE_MEDIUM_CHANGER:
1328         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1329         break;
1330     case TYPE_SCANNER:
1331         rc = scsi_req_scanner_length(cmd, dev, buf);
1332         break;
1333     default:
1334         rc = scsi_req_xfer(cmd, dev, buf);
1335         break;
1336     }
1337 
1338     if (rc != 0)
1339         return rc;
1340 
1341     memcpy(cmd->buf, buf, cmd->len);
1342     scsi_cmd_xfer_mode(cmd);
1343     cmd->lba = scsi_cmd_lba(cmd);
1344     return 0;
1345 }
1346 
1347 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1348 {
1349     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1350 
1351     scsi_device_set_ua(dev, sense);
1352     if (bus->info->change) {
1353         bus->info->change(bus, dev, sense);
1354     }
1355 }
1356 
1357 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1358 {
1359     assert(req->refcount > 0);
1360     req->refcount++;
1361     return req;
1362 }
1363 
1364 void scsi_req_unref(SCSIRequest *req)
1365 {
1366     assert(req->refcount > 0);
1367     if (--req->refcount == 0) {
1368         BusState *qbus = req->dev->qdev.parent_bus;
1369         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1370 
1371         if (bus->info->free_request && req->hba_private) {
1372             bus->info->free_request(bus, req->hba_private);
1373         }
1374         if (req->ops->free_req) {
1375             req->ops->free_req(req);
1376         }
1377         object_unref(OBJECT(req->dev));
1378         object_unref(OBJECT(qbus->parent));
1379         g_free(req);
1380     }
1381 }
1382 
1383 /* Tell the device that we finished processing this chunk of I/O.  It
1384    will start the next chunk or complete the command.  */
1385 void scsi_req_continue(SCSIRequest *req)
1386 {
1387     if (req->io_canceled) {
1388         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1389         return;
1390     }
1391     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1392     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1393         req->ops->write_data(req);
1394     } else {
1395         req->ops->read_data(req);
1396     }
1397 }
1398 
1399 /* Called by the devices when data is ready for the HBA.  The HBA should
1400    start a DMA operation to read or fill the device's data buffer.
1401    Once it completes, calling scsi_req_continue will restart I/O.  */
1402 void scsi_req_data(SCSIRequest *req, int len)
1403 {
1404     uint8_t *buf;
1405     if (req->io_canceled) {
1406         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1407         return;
1408     }
1409     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1410     assert(req->cmd.mode != SCSI_XFER_NONE);
1411     if (!req->sg) {
1412         req->residual -= len;
1413         req->bus->info->transfer_data(req, len);
1414         return;
1415     }
1416 
1417     /* If the device calls scsi_req_data and the HBA specified a
1418      * scatter/gather list, the transfer has to happen in a single
1419      * step.  */
1420     assert(!req->dma_started);
1421     req->dma_started = true;
1422 
1423     buf = scsi_req_get_buf(req);
1424     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1425         dma_buf_read(buf, len, &req->residual, req->sg,
1426                      MEMTXATTRS_UNSPECIFIED);
1427     } else {
1428         dma_buf_write(buf, len, &req->residual, req->sg,
1429                       MEMTXATTRS_UNSPECIFIED);
1430     }
1431     scsi_req_continue(req);
1432 }
1433 
1434 void scsi_req_print(SCSIRequest *req)
1435 {
1436     FILE *fp = stderr;
1437     int i;
1438 
1439     fprintf(fp, "[%s id=%d] %s",
1440             req->dev->qdev.parent_bus->name,
1441             req->dev->id,
1442             scsi_command_name(req->cmd.buf[0]));
1443     for (i = 1; i < req->cmd.len; i++) {
1444         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1445     }
1446     switch (req->cmd.mode) {
1447     case SCSI_XFER_NONE:
1448         fprintf(fp, " - none\n");
1449         break;
1450     case SCSI_XFER_FROM_DEV:
1451         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1452         break;
1453     case SCSI_XFER_TO_DEV:
1454         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1455         break;
1456     default:
1457         fprintf(fp, " - Oops\n");
1458         break;
1459     }
1460 }
1461 
1462 void scsi_req_complete_failed(SCSIRequest *req, int host_status)
1463 {
1464     SCSISense sense;
1465     int status;
1466 
1467     assert(req->status == -1 && req->host_status == -1);
1468     assert(req->ops != &reqops_unit_attention);
1469 
1470     if (!req->bus->info->fail) {
1471         status = scsi_sense_from_host_status(req->host_status, &sense);
1472         if (status == CHECK_CONDITION) {
1473             scsi_req_build_sense(req, sense);
1474         }
1475         scsi_req_complete(req, status);
1476         return;
1477     }
1478 
1479     req->host_status = host_status;
1480     scsi_req_ref(req);
1481     scsi_req_dequeue(req);
1482     req->bus->info->fail(req);
1483 
1484     /* Cancelled requests might end up being completed instead of cancelled */
1485     notifier_list_notify(&req->cancel_notifiers, req);
1486     scsi_req_unref(req);
1487 }
1488 
1489 void scsi_req_complete(SCSIRequest *req, int status)
1490 {
1491     assert(req->status == -1 && req->host_status == -1);
1492     req->status = status;
1493     req->host_status = SCSI_HOST_OK;
1494 
1495     assert(req->sense_len <= sizeof(req->sense));
1496     if (status == GOOD) {
1497         req->sense_len = 0;
1498     }
1499 
1500     if (req->sense_len) {
1501         memcpy(req->dev->sense, req->sense, req->sense_len);
1502         req->dev->sense_len = req->sense_len;
1503         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1504     } else {
1505         req->dev->sense_len = 0;
1506         req->dev->sense_is_ua = false;
1507     }
1508 
1509     /*
1510      * Unit attention state is now stored in the device's sense buffer
1511      * if the HBA didn't do autosense.  Clear the pending unit attention
1512      * flags.
1513      */
1514     scsi_clear_unit_attention(req);
1515 
1516     scsi_req_ref(req);
1517     scsi_req_dequeue(req);
1518     req->bus->info->complete(req, req->residual);
1519 
1520     /* Cancelled requests might end up being completed instead of cancelled */
1521     notifier_list_notify(&req->cancel_notifiers, req);
1522     scsi_req_unref(req);
1523 }
1524 
1525 /* Called by the devices when the request is canceled. */
1526 void scsi_req_cancel_complete(SCSIRequest *req)
1527 {
1528     assert(req->io_canceled);
1529     if (req->bus->info->cancel) {
1530         req->bus->info->cancel(req);
1531     }
1532     notifier_list_notify(&req->cancel_notifiers, req);
1533     scsi_req_unref(req);
1534 }
1535 
1536 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1537  * notifier list, the bus will be notified the requests cancellation is
1538  * completed.
1539  * */
1540 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1541 {
1542     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1543     if (notifier) {
1544         notifier_list_add(&req->cancel_notifiers, notifier);
1545     }
1546     if (req->io_canceled) {
1547         /* A blk_aio_cancel_async is pending; when it finishes,
1548          * scsi_req_cancel_complete will be called and will
1549          * call the notifier we just added.  Just wait for that.
1550          */
1551         assert(req->aiocb);
1552         return;
1553     }
1554     /* Dropped in scsi_req_cancel_complete.  */
1555     scsi_req_ref(req);
1556     scsi_req_dequeue(req);
1557     req->io_canceled = true;
1558     if (req->aiocb) {
1559         blk_aio_cancel_async(req->aiocb);
1560     } else {
1561         scsi_req_cancel_complete(req);
1562     }
1563 }
1564 
1565 void scsi_req_cancel(SCSIRequest *req)
1566 {
1567     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1568     if (!req->enqueued) {
1569         return;
1570     }
1571     assert(!req->io_canceled);
1572     /* Dropped in scsi_req_cancel_complete.  */
1573     scsi_req_ref(req);
1574     scsi_req_dequeue(req);
1575     req->io_canceled = true;
1576     if (req->aiocb) {
1577         blk_aio_cancel(req->aiocb);
1578     } else {
1579         scsi_req_cancel_complete(req);
1580     }
1581 }
1582 
1583 static int scsi_ua_precedence(SCSISense sense)
1584 {
1585     if (sense.key != UNIT_ATTENTION) {
1586         return INT_MAX;
1587     }
1588     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1589         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1590         return 1;
1591     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1592         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1593         return 2;
1594     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1595         /* These two go with "all others". */
1596         ;
1597     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1598         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1599          * POWER ON OCCURRED = 1
1600          * SCSI BUS RESET OCCURRED = 2
1601          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1602          * I_T NEXUS LOSS OCCURRED = 7
1603          */
1604         return sense.ascq;
1605     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1606         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1607         return 8;
1608     }
1609     return (sense.asc << 8) | sense.ascq;
1610 }
1611 
1612 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1613 {
1614     int prec1, prec2;
1615     if (sense.key != UNIT_ATTENTION) {
1616         return;
1617     }
1618     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1619                              sense.asc, sense.ascq);
1620 
1621     /*
1622      * Override a pre-existing unit attention condition, except for a more
1623      * important reset condition.
1624     */
1625     prec1 = scsi_ua_precedence(sdev->unit_attention);
1626     prec2 = scsi_ua_precedence(sense);
1627     if (prec2 < prec1) {
1628         sdev->unit_attention = sense;
1629     }
1630 }
1631 
1632 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1633 {
1634     SCSIRequest *req;
1635 
1636     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1637     while (!QTAILQ_EMPTY(&sdev->requests)) {
1638         req = QTAILQ_FIRST(&sdev->requests);
1639         scsi_req_cancel_async(req, NULL);
1640     }
1641     blk_drain(sdev->conf.blk);
1642     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1643     scsi_device_set_ua(sdev, sense);
1644 }
1645 
1646 static char *scsibus_get_dev_path(DeviceState *dev)
1647 {
1648     SCSIDevice *d = SCSI_DEVICE(dev);
1649     DeviceState *hba = dev->parent_bus->parent;
1650     char *id;
1651     char *path;
1652 
1653     id = qdev_get_dev_path(hba);
1654     if (id) {
1655         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1656     } else {
1657         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1658     }
1659     g_free(id);
1660     return path;
1661 }
1662 
1663 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1664 {
1665     SCSIDevice *d = SCSI_DEVICE(dev);
1666     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1667                            qdev_fw_name(dev), d->id, d->lun);
1668 }
1669 
1670 /* SCSI request list.  For simplicity, pv points to the whole device */
1671 
1672 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1673                              const VMStateField *field, JSONWriter *vmdesc)
1674 {
1675     SCSIDevice *s = pv;
1676     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1677     SCSIRequest *req;
1678 
1679     QTAILQ_FOREACH(req, &s->requests, next) {
1680         assert(!req->io_canceled);
1681         assert(req->status == -1 && req->host_status == -1);
1682         assert(req->enqueued);
1683 
1684         qemu_put_sbyte(f, req->retry ? 1 : 2);
1685         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1686         qemu_put_be32s(f, &req->tag);
1687         qemu_put_be32s(f, &req->lun);
1688         if (bus->info->save_request) {
1689             bus->info->save_request(f, req);
1690         }
1691         if (req->ops->save_request) {
1692             req->ops->save_request(f, req);
1693         }
1694     }
1695     qemu_put_sbyte(f, 0);
1696 
1697     return 0;
1698 }
1699 
1700 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1701                              const VMStateField *field)
1702 {
1703     SCSIDevice *s = pv;
1704     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1705     int8_t sbyte;
1706 
1707     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1708         uint8_t buf[SCSI_CMD_BUF_SIZE];
1709         uint32_t tag;
1710         uint32_t lun;
1711         SCSIRequest *req;
1712 
1713         qemu_get_buffer(f, buf, sizeof(buf));
1714         qemu_get_be32s(f, &tag);
1715         qemu_get_be32s(f, &lun);
1716         req = scsi_req_new(s, tag, lun, buf, NULL);
1717         req->retry = (sbyte == 1);
1718         if (bus->info->load_request) {
1719             req->hba_private = bus->info->load_request(f, req);
1720         }
1721         if (req->ops->load_request) {
1722             req->ops->load_request(f, req);
1723         }
1724 
1725         /* Just restart it later.  */
1726         scsi_req_enqueue_internal(req);
1727 
1728         /* At this point, the request will be kept alive by the reference
1729          * added by scsi_req_enqueue_internal, so we can release our reference.
1730          * The HBA of course will add its own reference in the load_request
1731          * callback if it needs to hold on the SCSIRequest.
1732          */
1733         scsi_req_unref(req);
1734     }
1735 
1736     return 0;
1737 }
1738 
1739 static const VMStateInfo vmstate_info_scsi_requests = {
1740     .name = "scsi-requests",
1741     .get  = get_scsi_requests,
1742     .put  = put_scsi_requests,
1743 };
1744 
1745 static bool scsi_sense_state_needed(void *opaque)
1746 {
1747     SCSIDevice *s = opaque;
1748 
1749     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1750 }
1751 
1752 static const VMStateDescription vmstate_scsi_sense_state = {
1753     .name = "SCSIDevice/sense",
1754     .version_id = 1,
1755     .minimum_version_id = 1,
1756     .needed = scsi_sense_state_needed,
1757     .fields = (VMStateField[]) {
1758         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1759                                 SCSI_SENSE_BUF_SIZE_OLD,
1760                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1761         VMSTATE_END_OF_LIST()
1762     }
1763 };
1764 
1765 const VMStateDescription vmstate_scsi_device = {
1766     .name = "SCSIDevice",
1767     .version_id = 1,
1768     .minimum_version_id = 1,
1769     .fields = (VMStateField[]) {
1770         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1771         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1772         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1773         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1774         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1775         VMSTATE_UINT32(sense_len, SCSIDevice),
1776         {
1777             .name         = "requests",
1778             .version_id   = 0,
1779             .field_exists = NULL,
1780             .size         = 0,   /* ouch */
1781             .info         = &vmstate_info_scsi_requests,
1782             .flags        = VMS_SINGLE,
1783             .offset       = 0,
1784         },
1785         VMSTATE_END_OF_LIST()
1786     },
1787     .subsections = (const VMStateDescription*[]) {
1788         &vmstate_scsi_sense_state,
1789         NULL
1790     }
1791 };
1792 
1793 static Property scsi_props[] = {
1794     DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
1795     DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
1796     DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
1797     DEFINE_PROP_END_OF_LIST(),
1798 };
1799 
1800 static void scsi_device_class_init(ObjectClass *klass, void *data)
1801 {
1802     DeviceClass *k = DEVICE_CLASS(klass);
1803     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1804     k->bus_type  = TYPE_SCSI_BUS;
1805     k->realize   = scsi_qdev_realize;
1806     k->unrealize = scsi_qdev_unrealize;
1807     device_class_set_props(k, scsi_props);
1808 }
1809 
1810 static void scsi_dev_instance_init(Object *obj)
1811 {
1812     DeviceState *dev = DEVICE(obj);
1813     SCSIDevice *s = SCSI_DEVICE(dev);
1814 
1815     device_add_bootindex_property(obj, &s->conf.bootindex,
1816                                   "bootindex", NULL,
1817                                   &s->qdev);
1818 }
1819 
1820 static const TypeInfo scsi_device_type_info = {
1821     .name = TYPE_SCSI_DEVICE,
1822     .parent = TYPE_DEVICE,
1823     .instance_size = sizeof(SCSIDevice),
1824     .abstract = true,
1825     .class_size = sizeof(SCSIDeviceClass),
1826     .class_init = scsi_device_class_init,
1827     .instance_init = scsi_dev_instance_init,
1828 };
1829 
1830 static void scsi_bus_class_init(ObjectClass *klass, void *data)
1831 {
1832     BusClass *k = BUS_CLASS(klass);
1833     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1834 
1835     k->get_dev_path = scsibus_get_dev_path;
1836     k->get_fw_dev_path = scsibus_get_fw_dev_path;
1837     k->check_address = scsi_bus_check_address;
1838     hc->unplug = qdev_simple_device_unplug_cb;
1839 }
1840 
1841 static const TypeInfo scsi_bus_info = {
1842     .name = TYPE_SCSI_BUS,
1843     .parent = TYPE_BUS,
1844     .instance_size = sizeof(SCSIBus),
1845     .class_init = scsi_bus_class_init,
1846     .interfaces = (InterfaceInfo[]) {
1847         { TYPE_HOTPLUG_HANDLER },
1848         { }
1849     }
1850 };
1851 
1852 static void scsi_register_types(void)
1853 {
1854     type_register_static(&scsi_bus_info);
1855     type_register_static(&scsi_device_type_info);
1856 }
1857 
1858 type_init(scsi_register_types)
1859