xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision 19ac7b29)
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 static void scsi_clear_reported_luns_changed(SCSIRequest *req);
26 
27 static int next_scsi_bus;
28 
29 static SCSIDevice *do_scsi_device_find(SCSIBus *bus,
30                                        int channel, int id, int lun,
31                                        bool include_unrealized)
32 {
33     BusChild *kid;
34     SCSIDevice *retval = NULL;
35 
36     QTAILQ_FOREACH_RCU(kid, &bus->qbus.children, sibling) {
37         DeviceState *qdev = kid->child;
38         SCSIDevice *dev = SCSI_DEVICE(qdev);
39 
40         if (dev->channel == channel && dev->id == id) {
41             if (dev->lun == lun) {
42                 retval = dev;
43                 break;
44             }
45 
46             /*
47              * If we don't find exact match (channel/bus/lun),
48              * we will return the first device which matches channel/bus
49              */
50 
51             if (!retval) {
52                 retval = dev;
53             }
54         }
55     }
56 
57     /*
58      * This function might run on the IO thread and we might race against
59      * main thread hot-plugging the device.
60      * We assume that as soon as .realized is set to true we can let
61      * the user access the device.
62      */
63 
64     if (retval && !include_unrealized && !qdev_is_realized(&retval->qdev)) {
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                        size_t buf_len, 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, buf_len);
112     if (bus->info->parse_cdb) {
113         rc = bus->info->parse_cdb(dev, cmd, buf, buf_len, 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_guarded(ctx, scsi_dma_restart_bh, s,
197                                    &DEVICE(s)->mem_reentrancy_guard);
198         qemu_bh_schedule(s->bh);
199     }
200 }
201 
202 static bool scsi_bus_is_address_free(SCSIBus *bus,
203                                      int channel, int target, int lun,
204                                      SCSIDevice **p_dev)
205 {
206     SCSIDevice *d;
207 
208     RCU_READ_LOCK_GUARD();
209     d = do_scsi_device_find(bus, channel, target, lun, true);
210     if (d && d->lun == lun) {
211         if (p_dev) {
212             *p_dev = d;
213         }
214         return false;
215     }
216     if (p_dev) {
217         *p_dev = NULL;
218     }
219     return true;
220 }
221 
222 static bool scsi_bus_check_address(BusState *qbus, DeviceState *qdev, Error **errp)
223 {
224     SCSIDevice *dev = SCSI_DEVICE(qdev);
225     SCSIBus *bus = SCSI_BUS(qbus);
226 
227     if (dev->channel > bus->info->max_channel) {
228         error_setg(errp, "bad scsi channel id: %d", dev->channel);
229         return false;
230     }
231     if (dev->id != -1 && dev->id > bus->info->max_target) {
232         error_setg(errp, "bad scsi device id: %d", dev->id);
233         return false;
234     }
235     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
236         error_setg(errp, "bad scsi device lun: %d", dev->lun);
237         return false;
238     }
239 
240     if (dev->id != -1 && dev->lun != -1) {
241         SCSIDevice *d;
242         if (!scsi_bus_is_address_free(bus, dev->channel, dev->id, dev->lun, &d)) {
243             error_setg(errp, "lun already used by '%s'", d->qdev.id);
244             return false;
245         }
246     }
247 
248     return true;
249 }
250 
251 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
252 {
253     SCSIDevice *dev = SCSI_DEVICE(qdev);
254     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
255     bool is_free;
256     Error *local_err = NULL;
257 
258     if (dev->id == -1) {
259         int id = -1;
260         if (dev->lun == -1) {
261             dev->lun = 0;
262         }
263         do {
264             is_free = scsi_bus_is_address_free(bus, dev->channel, ++id, dev->lun, NULL);
265         } while (!is_free && id < bus->info->max_target);
266         if (!is_free) {
267             error_setg(errp, "no free target");
268             return;
269         }
270         dev->id = id;
271     } else if (dev->lun == -1) {
272         int lun = -1;
273         do {
274             is_free = scsi_bus_is_address_free(bus, dev->channel, dev->id, ++lun, NULL);
275         } while (!is_free && lun < bus->info->max_lun);
276         if (!is_free) {
277             error_setg(errp, "no free lun");
278             return;
279         }
280         dev->lun = lun;
281     }
282 
283     QTAILQ_INIT(&dev->requests);
284     scsi_device_realize(dev, &local_err);
285     if (local_err) {
286         error_propagate(errp, local_err);
287         return;
288     }
289     dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
290             scsi_dma_restart_cb, dev);
291 }
292 
293 static void scsi_qdev_unrealize(DeviceState *qdev)
294 {
295     SCSIDevice *dev = SCSI_DEVICE(qdev);
296 
297     if (dev->vmsentry) {
298         qemu_del_vm_change_state_handler(dev->vmsentry);
299     }
300 
301     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
302 
303     scsi_device_unrealize(dev);
304 
305     blockdev_mark_auto_del(dev->conf.blk);
306 }
307 
308 /* handle legacy '-drive if=scsi,...' cmd line args */
309 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
310                                       int unit, bool removable, int bootindex,
311                                       bool share_rw,
312                                       BlockdevOnError rerror,
313                                       BlockdevOnError werror,
314                                       const char *serial, Error **errp)
315 {
316     const char *driver;
317     char *name;
318     DeviceState *dev;
319     DriveInfo *dinfo;
320 
321     if (blk_is_sg(blk)) {
322         driver = "scsi-generic";
323     } else {
324         dinfo = blk_legacy_dinfo(blk);
325         if (dinfo && dinfo->media_cd) {
326             driver = "scsi-cd";
327         } else {
328             driver = "scsi-hd";
329         }
330     }
331     dev = qdev_new(driver);
332     name = g_strdup_printf("legacy[%d]", unit);
333     object_property_add_child(OBJECT(bus), name, OBJECT(dev));
334     g_free(name);
335 
336     qdev_prop_set_uint32(dev, "scsi-id", unit);
337     if (bootindex >= 0) {
338         object_property_set_int(OBJECT(dev), "bootindex", bootindex,
339                                 &error_abort);
340     }
341     if (object_property_find(OBJECT(dev), "removable")) {
342         qdev_prop_set_bit(dev, "removable", removable);
343     }
344     if (serial && object_property_find(OBJECT(dev), "serial")) {
345         qdev_prop_set_string(dev, "serial", serial);
346     }
347     if (!qdev_prop_set_drive_err(dev, "drive", blk, errp)) {
348         object_unparent(OBJECT(dev));
349         return NULL;
350     }
351     if (!object_property_set_bool(OBJECT(dev), "share-rw", share_rw, errp)) {
352         object_unparent(OBJECT(dev));
353         return NULL;
354     }
355 
356     qdev_prop_set_enum(dev, "rerror", rerror);
357     qdev_prop_set_enum(dev, "werror", werror);
358 
359     if (!qdev_realize_and_unref(dev, &bus->qbus, errp)) {
360         object_unparent(OBJECT(dev));
361         return NULL;
362     }
363     return SCSI_DEVICE(dev);
364 }
365 
366 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
367 {
368     Location loc;
369     DriveInfo *dinfo;
370     int unit;
371 
372     loc_push_none(&loc);
373     for (unit = 0; unit <= bus->info->max_target; unit++) {
374         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
375         if (dinfo == NULL) {
376             continue;
377         }
378         qemu_opts_loc_restore(dinfo->opts);
379         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
380                                   unit, false, -1, false,
381                                   BLOCKDEV_ON_ERROR_AUTO,
382                                   BLOCKDEV_ON_ERROR_AUTO,
383                                   NULL, &error_fatal);
384     }
385     loc_pop(&loc);
386 }
387 
388 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
389 {
390     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
391     scsi_req_complete(req, CHECK_CONDITION);
392     return 0;
393 }
394 
395 static const struct SCSIReqOps reqops_invalid_field = {
396     .size         = sizeof(SCSIRequest),
397     .send_command = scsi_invalid_field
398 };
399 
400 /* SCSIReqOps implementation for invalid commands.  */
401 
402 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
403 {
404     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
405     scsi_req_complete(req, CHECK_CONDITION);
406     return 0;
407 }
408 
409 static const struct SCSIReqOps reqops_invalid_opcode = {
410     .size         = sizeof(SCSIRequest),
411     .send_command = scsi_invalid_command
412 };
413 
414 /* SCSIReqOps implementation for unit attention conditions.  */
415 
416 static void scsi_fetch_unit_attention_sense(SCSIRequest *req)
417 {
418     SCSISense *ua = NULL;
419 
420     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
421         ua = &req->dev->unit_attention;
422     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
423         ua = &req->bus->unit_attention;
424     }
425 
426     /*
427      * Fetch the unit attention sense immediately so that another
428      * scsi_req_new does not use reqops_unit_attention.
429      */
430     if (ua) {
431         scsi_req_build_sense(req, *ua);
432         *ua = SENSE_CODE(NO_SENSE);
433     }
434 }
435 
436 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
437 {
438     scsi_req_complete(req, CHECK_CONDITION);
439     return 0;
440 }
441 
442 static const struct SCSIReqOps reqops_unit_attention = {
443     .size         = sizeof(SCSIRequest),
444     .init_req     = scsi_fetch_unit_attention_sense,
445     .send_command = scsi_unit_attention
446 };
447 
448 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
449    an invalid LUN.  */
450 
451 typedef struct SCSITargetReq SCSITargetReq;
452 
453 struct SCSITargetReq {
454     SCSIRequest req;
455     int len;
456     uint8_t *buf;
457     int buf_len;
458 };
459 
460 static void store_lun(uint8_t *outbuf, int lun)
461 {
462     if (lun < 256) {
463         /* Simple logical unit addressing method*/
464         outbuf[0] = 0;
465         outbuf[1] = lun;
466     } else {
467         /* Flat space addressing method */
468         outbuf[0] = 0x40 | (lun >> 8);
469         outbuf[1] = (lun & 255);
470     }
471 }
472 
473 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
474 {
475     BusChild *kid;
476     int channel, id;
477     uint8_t tmp[8] = {0};
478     int len = 0;
479     GByteArray *buf;
480 
481     if (r->req.cmd.xfer < 16) {
482         return false;
483     }
484     if (r->req.cmd.buf[2] > 2) {
485         return false;
486     }
487 
488     /* reserve space for 63 LUNs*/
489     buf = g_byte_array_sized_new(512);
490 
491     channel = r->req.dev->channel;
492     id = r->req.dev->id;
493 
494     /* add size (will be updated later to correct value */
495     g_byte_array_append(buf, tmp, 8);
496     len += 8;
497 
498     /* add LUN0 */
499     g_byte_array_append(buf, tmp, 8);
500     len += 8;
501 
502     WITH_RCU_READ_LOCK_GUARD() {
503         QTAILQ_FOREACH_RCU(kid, &r->req.bus->qbus.children, sibling) {
504             DeviceState *qdev = kid->child;
505             SCSIDevice *dev = SCSI_DEVICE(qdev);
506 
507             if (dev->channel == channel && dev->id == id && dev->lun != 0 &&
508                 qdev_is_realized(&dev->qdev)) {
509                 store_lun(tmp, dev->lun);
510                 g_byte_array_append(buf, tmp, 8);
511                 len += 8;
512             }
513         }
514     }
515 
516     r->buf_len = len;
517     r->buf = g_byte_array_free(buf, FALSE);
518     r->len = MIN(len, r->req.cmd.xfer & ~7);
519 
520     /* store the LUN list length */
521     stl_be_p(&r->buf[0], len - 8);
522 
523     /*
524      * If a REPORT LUNS command enters the enabled command state, [...]
525      * the device server shall clear any pending unit attention condition
526      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
527      */
528     scsi_clear_reported_luns_changed(&r->req);
529 
530     return true;
531 }
532 
533 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
534 {
535     assert(r->req.dev->lun != r->req.lun);
536 
537     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
538 
539     if (r->req.cmd.buf[1] & 0x2) {
540         /* Command support data - optional, not implemented */
541         return false;
542     }
543 
544     if (r->req.cmd.buf[1] & 0x1) {
545         /* Vital product data */
546         uint8_t page_code = r->req.cmd.buf[2];
547         r->buf[r->len++] = page_code ; /* this page */
548         r->buf[r->len++] = 0x00;
549 
550         switch (page_code) {
551         case 0x00: /* Supported page codes, mandatory */
552         {
553             int pages;
554             pages = r->len++;
555             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
556             r->buf[pages] = r->len - pages - 1; /* number of pages */
557             break;
558         }
559         default:
560             return false;
561         }
562         /* done with EVPD */
563         assert(r->len < r->buf_len);
564         r->len = MIN(r->req.cmd.xfer, r->len);
565         return true;
566     }
567 
568     /* Standard INQUIRY data */
569     if (r->req.cmd.buf[2] != 0) {
570         return false;
571     }
572 
573     /* PAGE CODE == 0 */
574     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
575     memset(r->buf, 0, r->len);
576     if (r->req.lun != 0) {
577         r->buf[0] = TYPE_NO_LUN;
578     } else {
579         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
580         r->buf[2] = 5; /* Version */
581         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
582         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
583         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
584         memcpy(&r->buf[8], "QEMU    ", 8);
585         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
586         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
587     }
588     return true;
589 }
590 
591 static size_t scsi_sense_len(SCSIRequest *req)
592 {
593     if (req->dev->type == TYPE_SCANNER)
594         return SCSI_SENSE_LEN_SCANNER;
595     else
596         return SCSI_SENSE_LEN;
597 }
598 
599 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
600 {
601     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
602     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
603 
604     if (req->lun != 0 &&
605         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
606         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
607         scsi_req_complete(req, CHECK_CONDITION);
608         return 0;
609     }
610     switch (buf[0]) {
611     case REPORT_LUNS:
612         if (!scsi_target_emulate_report_luns(r)) {
613             goto illegal_request;
614         }
615         break;
616     case INQUIRY:
617         if (!scsi_target_emulate_inquiry(r)) {
618             goto illegal_request;
619         }
620         break;
621     case REQUEST_SENSE:
622         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
623         if (req->lun != 0) {
624             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
625 
626             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
627                                           sense, fixed_sense);
628         } else {
629             r->len = scsi_device_get_sense(r->req.dev, r->buf,
630                                            MIN(req->cmd.xfer, r->buf_len),
631                                            fixed_sense);
632         }
633         if (r->req.dev->sense_is_ua) {
634             scsi_device_unit_attention_reported(req->dev);
635             r->req.dev->sense_len = 0;
636             r->req.dev->sense_is_ua = false;
637         }
638         break;
639     case TEST_UNIT_READY:
640         break;
641     default:
642         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
643         scsi_req_complete(req, CHECK_CONDITION);
644         return 0;
645     illegal_request:
646         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
647         scsi_req_complete(req, CHECK_CONDITION);
648         return 0;
649     }
650 
651     if (!r->len) {
652         scsi_req_complete(req, GOOD);
653     }
654     return r->len;
655 }
656 
657 static void scsi_target_read_data(SCSIRequest *req)
658 {
659     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
660     uint32_t n;
661 
662     n = r->len;
663     if (n > 0) {
664         r->len = 0;
665         scsi_req_data(&r->req, n);
666     } else {
667         scsi_req_complete(&r->req, GOOD);
668     }
669 }
670 
671 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
672 {
673     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
674 
675     return r->buf;
676 }
677 
678 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
679 {
680     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
681 
682     r->buf = g_malloc(len);
683     r->buf_len = len;
684 
685     return r->buf;
686 }
687 
688 static void scsi_target_free_buf(SCSIRequest *req)
689 {
690     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
691 
692     g_free(r->buf);
693 }
694 
695 static const struct SCSIReqOps reqops_target_command = {
696     .size         = sizeof(SCSITargetReq),
697     .send_command = scsi_target_send_command,
698     .read_data    = scsi_target_read_data,
699     .get_buf      = scsi_target_get_buf,
700     .free_req     = scsi_target_free_buf,
701 };
702 
703 
704 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
705                             uint32_t tag, uint32_t lun, void *hba_private)
706 {
707     SCSIRequest *req;
708     SCSIBus *bus = scsi_bus_from_device(d);
709     BusState *qbus = BUS(bus);
710     const int memset_off = offsetof(SCSIRequest, sense)
711                            + sizeof(req->sense);
712 
713     req = g_malloc(reqops->size);
714     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
715     req->refcount = 1;
716     req->bus = bus;
717     req->dev = d;
718     req->tag = tag;
719     req->lun = lun;
720     req->hba_private = hba_private;
721     req->status = -1;
722     req->host_status = -1;
723     req->ops = reqops;
724     object_ref(OBJECT(d));
725     object_ref(OBJECT(qbus->parent));
726     notifier_list_init(&req->cancel_notifiers);
727 
728     if (reqops->init_req) {
729         reqops->init_req(req);
730     }
731 
732     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
733     return req;
734 }
735 
736 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
737                           uint8_t *buf, size_t buf_len, void *hba_private)
738 {
739     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
740     const SCSIReqOps *ops;
741     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
742     SCSIRequest *req;
743     SCSICommand cmd = { .len = 0 };
744     int ret;
745 
746     if (buf_len == 0) {
747         trace_scsi_req_parse_bad(d->id, lun, tag, 0);
748         goto invalid_opcode;
749     }
750 
751     if ((d->unit_attention.key == UNIT_ATTENTION ||
752          bus->unit_attention.key == UNIT_ATTENTION) &&
753         (buf[0] != INQUIRY &&
754          buf[0] != REPORT_LUNS &&
755          buf[0] != GET_CONFIGURATION &&
756          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
757 
758          /*
759           * If we already have a pending unit attention condition,
760           * report this one before triggering another one.
761           */
762          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
763         ops = &reqops_unit_attention;
764     } else if (lun != d->lun ||
765                buf[0] == REPORT_LUNS ||
766                (buf[0] == REQUEST_SENSE && d->sense_len)) {
767         ops = &reqops_target_command;
768     } else {
769         ops = NULL;
770     }
771 
772     if (ops != NULL || !sc->parse_cdb) {
773         ret = scsi_req_parse_cdb(d, &cmd, buf, buf_len);
774     } else {
775         ret = sc->parse_cdb(d, &cmd, buf, buf_len, hba_private);
776     }
777 
778     if (ret != 0) {
779         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
780 invalid_opcode:
781         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
782     } else {
783         assert(cmd.len != 0);
784         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
785                               cmd.mode, cmd.xfer);
786         if (cmd.lba != -1) {
787             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
788                                       cmd.lba);
789         }
790 
791         if (cmd.xfer > INT32_MAX) {
792             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
793         } else if (ops) {
794             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
795         } else {
796             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
797         }
798     }
799 
800     req->cmd = cmd;
801     req->residual = req->cmd.xfer;
802 
803     switch (buf[0]) {
804     case INQUIRY:
805         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
806         break;
807     case TEST_UNIT_READY:
808         trace_scsi_test_unit_ready(d->id, lun, tag);
809         break;
810     case REPORT_LUNS:
811         trace_scsi_report_luns(d->id, lun, tag);
812         break;
813     case REQUEST_SENSE:
814         trace_scsi_request_sense(d->id, lun, tag);
815         break;
816     default:
817         break;
818     }
819 
820     return req;
821 }
822 
823 uint8_t *scsi_req_get_buf(SCSIRequest *req)
824 {
825     return req->ops->get_buf(req);
826 }
827 
828 static void scsi_clear_reported_luns_changed(SCSIRequest *req)
829 {
830     SCSISense *ua;
831 
832     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
833         ua = &req->dev->unit_attention;
834     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
835         ua = &req->bus->unit_attention;
836     } else {
837         return;
838     }
839 
840     if (ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
841         ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq) {
842         *ua = SENSE_CODE(NO_SENSE);
843     }
844 }
845 
846 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
847 {
848     int ret;
849 
850     assert(len >= 14);
851     if (!req->sense_len) {
852         return 0;
853     }
854 
855     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
856 
857     /*
858      * FIXME: clearing unit attention conditions upon autosense should be done
859      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
860      * (SAM-5, 5.14).
861      *
862      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
863      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
864      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
865      */
866     if (req->dev->sense_is_ua) {
867         scsi_device_unit_attention_reported(req->dev);
868         req->dev->sense_len = 0;
869         req->dev->sense_is_ua = false;
870     }
871     return ret;
872 }
873 
874 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
875 {
876     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
877 }
878 
879 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
880 {
881     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
882                                sense.key, sense.asc, sense.ascq);
883     req->sense_len = scsi_build_sense(req->sense, sense);
884 }
885 
886 static void scsi_req_enqueue_internal(SCSIRequest *req)
887 {
888     assert(!req->enqueued);
889     scsi_req_ref(req);
890     if (req->bus->info->get_sg_list) {
891         req->sg = req->bus->info->get_sg_list(req);
892     } else {
893         req->sg = NULL;
894     }
895     req->enqueued = true;
896     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
897 }
898 
899 int32_t scsi_req_enqueue(SCSIRequest *req)
900 {
901     int32_t rc;
902 
903     assert(!req->retry);
904     scsi_req_enqueue_internal(req);
905     scsi_req_ref(req);
906     rc = req->ops->send_command(req, req->cmd.buf);
907     scsi_req_unref(req);
908     return rc;
909 }
910 
911 static void scsi_req_dequeue(SCSIRequest *req)
912 {
913     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
914     req->retry = false;
915     if (req->enqueued) {
916         QTAILQ_REMOVE(&req->dev->requests, req, next);
917         req->enqueued = false;
918         scsi_req_unref(req);
919     }
920 }
921 
922 static int scsi_get_performance_length(int num_desc, int type, int data_type)
923 {
924     /* MMC-6, paragraph 6.7.  */
925     switch (type) {
926     case 0:
927         if ((data_type & 3) == 0) {
928             /* Each descriptor is as in Table 295 - Nominal performance.  */
929             return 16 * num_desc + 8;
930         } else {
931             /* Each descriptor is as in Table 296 - Exceptions.  */
932             return 6 * num_desc + 8;
933         }
934     case 1:
935     case 4:
936     case 5:
937         return 8 * num_desc + 8;
938     case 2:
939         return 2048 * num_desc + 8;
940     case 3:
941         return 16 * num_desc + 8;
942     default:
943         return 8;
944     }
945 }
946 
947 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
948 {
949     int byte_block = (buf[2] >> 2) & 0x1;
950     int type = (buf[2] >> 4) & 0x1;
951     int xfer_unit;
952 
953     if (byte_block) {
954         if (type) {
955             xfer_unit = dev->blocksize;
956         } else {
957             xfer_unit = 512;
958         }
959     } else {
960         xfer_unit = 1;
961     }
962 
963     return xfer_unit;
964 }
965 
966 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
967 {
968     int length = buf[2] & 0x3;
969     int xfer;
970     int unit = ata_passthrough_xfer_unit(dev, buf);
971 
972     switch (length) {
973     case 0:
974     case 3: /* USB-specific.  */
975     default:
976         xfer = 0;
977         break;
978     case 1:
979         xfer = buf[3];
980         break;
981     case 2:
982         xfer = buf[4];
983         break;
984     }
985 
986     return xfer * unit;
987 }
988 
989 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
990 {
991     int extend = buf[1] & 0x1;
992     int length = buf[2] & 0x3;
993     int xfer;
994     int unit = ata_passthrough_xfer_unit(dev, buf);
995 
996     switch (length) {
997     case 0:
998     case 3: /* USB-specific.  */
999     default:
1000         xfer = 0;
1001         break;
1002     case 1:
1003         xfer = buf[4];
1004         xfer |= (extend ? buf[3] << 8 : 0);
1005         break;
1006     case 2:
1007         xfer = buf[6];
1008         xfer |= (extend ? buf[5] << 8 : 0);
1009         break;
1010     }
1011 
1012     return xfer * unit;
1013 }
1014 
1015 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1016 {
1017     cmd->xfer = scsi_cdb_xfer(buf);
1018     switch (buf[0]) {
1019     case TEST_UNIT_READY:
1020     case REWIND:
1021     case START_STOP:
1022     case SET_CAPACITY:
1023     case WRITE_FILEMARKS:
1024     case WRITE_FILEMARKS_16:
1025     case SPACE:
1026     case RESERVE:
1027     case RELEASE:
1028     case ERASE:
1029     case ALLOW_MEDIUM_REMOVAL:
1030     case SEEK_10:
1031     case SYNCHRONIZE_CACHE:
1032     case SYNCHRONIZE_CACHE_16:
1033     case LOCATE_16:
1034     case LOCK_UNLOCK_CACHE:
1035     case SET_CD_SPEED:
1036     case SET_LIMITS:
1037     case WRITE_LONG_10:
1038     case UPDATE_BLOCK:
1039     case RESERVE_TRACK:
1040     case SET_READ_AHEAD:
1041     case PRE_FETCH:
1042     case PRE_FETCH_16:
1043     case ALLOW_OVERWRITE:
1044         cmd->xfer = 0;
1045         break;
1046     case VERIFY_10:
1047     case VERIFY_12:
1048     case VERIFY_16:
1049         if ((buf[1] & 2) == 0) {
1050             cmd->xfer = 0;
1051         } else if ((buf[1] & 4) != 0) {
1052             cmd->xfer = 1;
1053         }
1054         cmd->xfer *= dev->blocksize;
1055         break;
1056     case MODE_SENSE:
1057         break;
1058     case WRITE_SAME_10:
1059     case WRITE_SAME_16:
1060         cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
1061         break;
1062     case READ_CAPACITY_10:
1063         cmd->xfer = 8;
1064         break;
1065     case READ_BLOCK_LIMITS:
1066         cmd->xfer = 6;
1067         break;
1068     case SEND_VOLUME_TAG:
1069         /* GPCMD_SET_STREAMING from multimedia commands.  */
1070         if (dev->type == TYPE_ROM) {
1071             cmd->xfer = buf[10] | (buf[9] << 8);
1072         } else {
1073             cmd->xfer = buf[9] | (buf[8] << 8);
1074         }
1075         break;
1076     case WRITE_6:
1077         /* length 0 means 256 blocks */
1078         if (cmd->xfer == 0) {
1079             cmd->xfer = 256;
1080         }
1081         /* fall through */
1082     case WRITE_10:
1083     case WRITE_VERIFY_10:
1084     case WRITE_12:
1085     case WRITE_VERIFY_12:
1086     case WRITE_16:
1087     case WRITE_VERIFY_16:
1088         cmd->xfer *= dev->blocksize;
1089         break;
1090     case READ_6:
1091     case READ_REVERSE:
1092         /* length 0 means 256 blocks */
1093         if (cmd->xfer == 0) {
1094             cmd->xfer = 256;
1095         }
1096         /* fall through */
1097     case READ_10:
1098     case READ_12:
1099     case READ_16:
1100         cmd->xfer *= dev->blocksize;
1101         break;
1102     case FORMAT_UNIT:
1103         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1104          * for block devices are restricted to the header right now.  */
1105         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1106             cmd->xfer = 12;
1107         } else {
1108             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1109         }
1110         break;
1111     case INQUIRY:
1112     case RECEIVE_DIAGNOSTIC:
1113     case SEND_DIAGNOSTIC:
1114         cmd->xfer = buf[4] | (buf[3] << 8);
1115         break;
1116     case READ_CD:
1117     case READ_BUFFER:
1118     case WRITE_BUFFER:
1119     case SEND_CUE_SHEET:
1120         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1121         break;
1122     case PERSISTENT_RESERVE_OUT:
1123         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1124         break;
1125     case ERASE_12:
1126         if (dev->type == TYPE_ROM) {
1127             /* MMC command GET PERFORMANCE.  */
1128             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1129                                                     buf[10], buf[1] & 0x1f);
1130         }
1131         break;
1132     case MECHANISM_STATUS:
1133     case READ_DVD_STRUCTURE:
1134     case SEND_DVD_STRUCTURE:
1135     case MAINTENANCE_OUT:
1136     case MAINTENANCE_IN:
1137         if (dev->type == TYPE_ROM) {
1138             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1139             cmd->xfer = buf[9] | (buf[8] << 8);
1140         }
1141         break;
1142     case ATA_PASSTHROUGH_12:
1143         if (dev->type == TYPE_ROM) {
1144             /* BLANK command of MMC */
1145             cmd->xfer = 0;
1146         } else {
1147             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1148         }
1149         break;
1150     case ATA_PASSTHROUGH_16:
1151         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1152         break;
1153     }
1154     return 0;
1155 }
1156 
1157 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1158 {
1159     switch (buf[0]) {
1160     /* stream commands */
1161     case ERASE_12:
1162     case ERASE_16:
1163         cmd->xfer = 0;
1164         break;
1165     case READ_6:
1166     case READ_REVERSE:
1167     case RECOVER_BUFFERED_DATA:
1168     case WRITE_6:
1169         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1170         if (buf[1] & 0x01) { /* fixed */
1171             cmd->xfer *= dev->blocksize;
1172         }
1173         break;
1174     case READ_16:
1175     case READ_REVERSE_16:
1176     case VERIFY_16:
1177     case WRITE_16:
1178         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1179         if (buf[1] & 0x01) { /* fixed */
1180             cmd->xfer *= dev->blocksize;
1181         }
1182         break;
1183     case REWIND:
1184     case LOAD_UNLOAD:
1185         cmd->xfer = 0;
1186         break;
1187     case SPACE_16:
1188         cmd->xfer = buf[13] | (buf[12] << 8);
1189         break;
1190     case READ_POSITION:
1191         switch (buf[1] & 0x1f) /* operation code */ {
1192         case SHORT_FORM_BLOCK_ID:
1193         case SHORT_FORM_VENDOR_SPECIFIC:
1194             cmd->xfer = 20;
1195             break;
1196         case LONG_FORM:
1197             cmd->xfer = 32;
1198             break;
1199         case EXTENDED_FORM:
1200             cmd->xfer = buf[8] | (buf[7] << 8);
1201             break;
1202         default:
1203             return -1;
1204         }
1205 
1206         break;
1207     case FORMAT_UNIT:
1208         cmd->xfer = buf[4] | (buf[3] << 8);
1209         break;
1210     /* generic commands */
1211     default:
1212         return scsi_req_xfer(cmd, dev, buf);
1213     }
1214     return 0;
1215 }
1216 
1217 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1218 {
1219     switch (buf[0]) {
1220     /* medium changer commands */
1221     case EXCHANGE_MEDIUM:
1222     case INITIALIZE_ELEMENT_STATUS:
1223     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1224     case MOVE_MEDIUM:
1225     case POSITION_TO_ELEMENT:
1226         cmd->xfer = 0;
1227         break;
1228     case READ_ELEMENT_STATUS:
1229         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1230         break;
1231 
1232     /* generic commands */
1233     default:
1234         return scsi_req_xfer(cmd, dev, buf);
1235     }
1236     return 0;
1237 }
1238 
1239 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1240 {
1241     switch (buf[0]) {
1242     /* Scanner commands */
1243     case OBJECT_POSITION:
1244         cmd->xfer = 0;
1245         break;
1246     case SCAN:
1247         cmd->xfer = buf[4];
1248         break;
1249     case READ_10:
1250     case SEND:
1251     case GET_WINDOW:
1252     case SET_WINDOW:
1253         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1254         break;
1255     default:
1256         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1257         return scsi_req_xfer(cmd, dev, buf);
1258     }
1259 
1260     return 0;
1261 }
1262 
1263 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1264 {
1265     if (!cmd->xfer) {
1266         cmd->mode = SCSI_XFER_NONE;
1267         return;
1268     }
1269     switch (cmd->buf[0]) {
1270     case WRITE_6:
1271     case WRITE_10:
1272     case WRITE_VERIFY_10:
1273     case WRITE_12:
1274     case WRITE_VERIFY_12:
1275     case WRITE_16:
1276     case WRITE_VERIFY_16:
1277     case VERIFY_10:
1278     case VERIFY_12:
1279     case VERIFY_16:
1280     case COPY:
1281     case COPY_VERIFY:
1282     case COMPARE:
1283     case CHANGE_DEFINITION:
1284     case LOG_SELECT:
1285     case MODE_SELECT:
1286     case MODE_SELECT_10:
1287     case SEND_DIAGNOSTIC:
1288     case WRITE_BUFFER:
1289     case FORMAT_UNIT:
1290     case REASSIGN_BLOCKS:
1291     case SEARCH_EQUAL:
1292     case SEARCH_HIGH:
1293     case SEARCH_LOW:
1294     case UPDATE_BLOCK:
1295     case WRITE_LONG_10:
1296     case WRITE_SAME_10:
1297     case WRITE_SAME_16:
1298     case UNMAP:
1299     case SEARCH_HIGH_12:
1300     case SEARCH_EQUAL_12:
1301     case SEARCH_LOW_12:
1302     case MEDIUM_SCAN:
1303     case SEND_VOLUME_TAG:
1304     case SEND_CUE_SHEET:
1305     case SEND_DVD_STRUCTURE:
1306     case PERSISTENT_RESERVE_OUT:
1307     case MAINTENANCE_OUT:
1308     case SET_WINDOW:
1309     case SCAN:
1310         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1311          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1312          */
1313         cmd->mode = SCSI_XFER_TO_DEV;
1314         break;
1315     case ATA_PASSTHROUGH_12:
1316     case ATA_PASSTHROUGH_16:
1317         /* T_DIR */
1318         cmd->mode = (cmd->buf[2] & 0x8) ?
1319                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1320         break;
1321     default:
1322         cmd->mode = SCSI_XFER_FROM_DEV;
1323         break;
1324     }
1325 }
1326 
1327 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
1328                        size_t buf_len)
1329 {
1330     int rc;
1331     int len;
1332 
1333     cmd->lba = -1;
1334     len = scsi_cdb_length(buf);
1335     if (len < 0 || len > buf_len) {
1336         return -1;
1337     }
1338 
1339     cmd->len = len;
1340     switch (dev->type) {
1341     case TYPE_TAPE:
1342         rc = scsi_req_stream_xfer(cmd, dev, buf);
1343         break;
1344     case TYPE_MEDIUM_CHANGER:
1345         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1346         break;
1347     case TYPE_SCANNER:
1348         rc = scsi_req_scanner_length(cmd, dev, buf);
1349         break;
1350     default:
1351         rc = scsi_req_xfer(cmd, dev, buf);
1352         break;
1353     }
1354 
1355     if (rc != 0)
1356         return rc;
1357 
1358     memcpy(cmd->buf, buf, cmd->len);
1359     scsi_cmd_xfer_mode(cmd);
1360     cmd->lba = scsi_cmd_lba(cmd);
1361     return 0;
1362 }
1363 
1364 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1365 {
1366     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1367 
1368     scsi_device_set_ua(dev, sense);
1369     if (bus->info->change) {
1370         bus->info->change(bus, dev, sense);
1371     }
1372 }
1373 
1374 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1375 {
1376     assert(req->refcount > 0);
1377     req->refcount++;
1378     return req;
1379 }
1380 
1381 void scsi_req_unref(SCSIRequest *req)
1382 {
1383     assert(req->refcount > 0);
1384     if (--req->refcount == 0) {
1385         BusState *qbus = req->dev->qdev.parent_bus;
1386         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1387 
1388         if (bus->info->free_request && req->hba_private) {
1389             bus->info->free_request(bus, req->hba_private);
1390         }
1391         if (req->ops->free_req) {
1392             req->ops->free_req(req);
1393         }
1394         object_unref(OBJECT(req->dev));
1395         object_unref(OBJECT(qbus->parent));
1396         g_free(req);
1397     }
1398 }
1399 
1400 /* Tell the device that we finished processing this chunk of I/O.  It
1401    will start the next chunk or complete the command.  */
1402 void scsi_req_continue(SCSIRequest *req)
1403 {
1404     if (req->io_canceled) {
1405         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1406         return;
1407     }
1408     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1409     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1410         req->ops->write_data(req);
1411     } else {
1412         req->ops->read_data(req);
1413     }
1414 }
1415 
1416 /* Called by the devices when data is ready for the HBA.  The HBA should
1417    start a DMA operation to read or fill the device's data buffer.
1418    Once it completes, calling scsi_req_continue will restart I/O.  */
1419 void scsi_req_data(SCSIRequest *req, int len)
1420 {
1421     uint8_t *buf;
1422     if (req->io_canceled) {
1423         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1424         return;
1425     }
1426     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1427     assert(req->cmd.mode != SCSI_XFER_NONE);
1428     if (!req->sg) {
1429         req->residual -= len;
1430         req->bus->info->transfer_data(req, len);
1431         return;
1432     }
1433 
1434     /* If the device calls scsi_req_data and the HBA specified a
1435      * scatter/gather list, the transfer has to happen in a single
1436      * step.  */
1437     assert(!req->dma_started);
1438     req->dma_started = true;
1439 
1440     buf = scsi_req_get_buf(req);
1441     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1442         dma_buf_read(buf, len, &req->residual, req->sg,
1443                      MEMTXATTRS_UNSPECIFIED);
1444     } else {
1445         dma_buf_write(buf, len, &req->residual, req->sg,
1446                       MEMTXATTRS_UNSPECIFIED);
1447     }
1448     scsi_req_continue(req);
1449 }
1450 
1451 void scsi_req_print(SCSIRequest *req)
1452 {
1453     FILE *fp = stderr;
1454     int i;
1455 
1456     fprintf(fp, "[%s id=%d] %s",
1457             req->dev->qdev.parent_bus->name,
1458             req->dev->id,
1459             scsi_command_name(req->cmd.buf[0]));
1460     for (i = 1; i < req->cmd.len; i++) {
1461         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1462     }
1463     switch (req->cmd.mode) {
1464     case SCSI_XFER_NONE:
1465         fprintf(fp, " - none\n");
1466         break;
1467     case SCSI_XFER_FROM_DEV:
1468         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1469         break;
1470     case SCSI_XFER_TO_DEV:
1471         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1472         break;
1473     default:
1474         fprintf(fp, " - Oops\n");
1475         break;
1476     }
1477 }
1478 
1479 void scsi_req_complete_failed(SCSIRequest *req, int host_status)
1480 {
1481     SCSISense sense;
1482     int status;
1483 
1484     assert(req->status == -1 && req->host_status == -1);
1485     assert(req->ops != &reqops_unit_attention);
1486 
1487     if (!req->bus->info->fail) {
1488         status = scsi_sense_from_host_status(req->host_status, &sense);
1489         if (status == CHECK_CONDITION) {
1490             scsi_req_build_sense(req, sense);
1491         }
1492         scsi_req_complete(req, status);
1493         return;
1494     }
1495 
1496     req->host_status = host_status;
1497     scsi_req_ref(req);
1498     scsi_req_dequeue(req);
1499     req->bus->info->fail(req);
1500 
1501     /* Cancelled requests might end up being completed instead of cancelled */
1502     notifier_list_notify(&req->cancel_notifiers, req);
1503     scsi_req_unref(req);
1504 }
1505 
1506 void scsi_req_complete(SCSIRequest *req, int status)
1507 {
1508     assert(req->status == -1 && req->host_status == -1);
1509     req->status = status;
1510     req->host_status = SCSI_HOST_OK;
1511 
1512     assert(req->sense_len <= sizeof(req->sense));
1513     if (status == GOOD) {
1514         req->sense_len = 0;
1515     }
1516 
1517     if (req->sense_len) {
1518         memcpy(req->dev->sense, req->sense, req->sense_len);
1519         req->dev->sense_len = req->sense_len;
1520         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1521     } else {
1522         req->dev->sense_len = 0;
1523         req->dev->sense_is_ua = false;
1524     }
1525 
1526     scsi_req_ref(req);
1527     scsi_req_dequeue(req);
1528     req->bus->info->complete(req, req->residual);
1529 
1530     /* Cancelled requests might end up being completed instead of cancelled */
1531     notifier_list_notify(&req->cancel_notifiers, req);
1532     scsi_req_unref(req);
1533 }
1534 
1535 /* Called by the devices when the request is canceled. */
1536 void scsi_req_cancel_complete(SCSIRequest *req)
1537 {
1538     assert(req->io_canceled);
1539     if (req->bus->info->cancel) {
1540         req->bus->info->cancel(req);
1541     }
1542     notifier_list_notify(&req->cancel_notifiers, req);
1543     scsi_req_unref(req);
1544 }
1545 
1546 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1547  * notifier list, the bus will be notified the requests cancellation is
1548  * completed.
1549  * */
1550 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1551 {
1552     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1553     if (notifier) {
1554         notifier_list_add(&req->cancel_notifiers, notifier);
1555     }
1556     if (req->io_canceled) {
1557         /* A blk_aio_cancel_async is pending; when it finishes,
1558          * scsi_req_cancel_complete will be called and will
1559          * call the notifier we just added.  Just wait for that.
1560          */
1561         assert(req->aiocb);
1562         return;
1563     }
1564     /* Dropped in scsi_req_cancel_complete.  */
1565     scsi_req_ref(req);
1566     scsi_req_dequeue(req);
1567     req->io_canceled = true;
1568     if (req->aiocb) {
1569         blk_aio_cancel_async(req->aiocb);
1570     } else {
1571         scsi_req_cancel_complete(req);
1572     }
1573 }
1574 
1575 void scsi_req_cancel(SCSIRequest *req)
1576 {
1577     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1578     if (!req->enqueued) {
1579         return;
1580     }
1581     assert(!req->io_canceled);
1582     /* Dropped in scsi_req_cancel_complete.  */
1583     scsi_req_ref(req);
1584     scsi_req_dequeue(req);
1585     req->io_canceled = true;
1586     if (req->aiocb) {
1587         blk_aio_cancel(req->aiocb);
1588     } else {
1589         scsi_req_cancel_complete(req);
1590     }
1591 }
1592 
1593 static int scsi_ua_precedence(SCSISense sense)
1594 {
1595     if (sense.key != UNIT_ATTENTION) {
1596         return INT_MAX;
1597     }
1598     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1599         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1600         return 1;
1601     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1602         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1603         return 2;
1604     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1605         /* These two go with "all others". */
1606         ;
1607     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1608         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1609          * POWER ON OCCURRED = 1
1610          * SCSI BUS RESET OCCURRED = 2
1611          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1612          * I_T NEXUS LOSS OCCURRED = 7
1613          */
1614         return sense.ascq;
1615     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1616         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1617         return 8;
1618     }
1619     return (sense.asc << 8) | sense.ascq;
1620 }
1621 
1622 void scsi_bus_set_ua(SCSIBus *bus, SCSISense sense)
1623 {
1624     int prec1, prec2;
1625     if (sense.key != UNIT_ATTENTION) {
1626         return;
1627     }
1628 
1629     /*
1630      * Override a pre-existing unit attention condition, except for a more
1631      * important reset condition.
1632      */
1633     prec1 = scsi_ua_precedence(bus->unit_attention);
1634     prec2 = scsi_ua_precedence(sense);
1635     if (prec2 < prec1) {
1636         bus->unit_attention = sense;
1637     }
1638 }
1639 
1640 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1641 {
1642     int prec1, prec2;
1643     if (sense.key != UNIT_ATTENTION) {
1644         return;
1645     }
1646     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1647                              sense.asc, sense.ascq);
1648 
1649     /*
1650      * Override a pre-existing unit attention condition, except for a more
1651      * important reset condition.
1652     */
1653     prec1 = scsi_ua_precedence(sdev->unit_attention);
1654     prec2 = scsi_ua_precedence(sense);
1655     if (prec2 < prec1) {
1656         sdev->unit_attention = sense;
1657     }
1658 }
1659 
1660 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1661 {
1662     SCSIRequest *req;
1663 
1664     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1665     while (!QTAILQ_EMPTY(&sdev->requests)) {
1666         req = QTAILQ_FIRST(&sdev->requests);
1667         scsi_req_cancel_async(req, NULL);
1668     }
1669     blk_drain(sdev->conf.blk);
1670     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1671     scsi_device_set_ua(sdev, sense);
1672 }
1673 
1674 void scsi_device_drained_begin(SCSIDevice *sdev)
1675 {
1676     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, sdev->qdev.parent_bus);
1677     if (!bus) {
1678         return;
1679     }
1680 
1681     assert(qemu_get_current_aio_context() == qemu_get_aio_context());
1682     assert(bus->drain_count < INT_MAX);
1683 
1684     /*
1685      * Multiple BlockBackends can be on a SCSIBus and each may begin/end
1686      * draining at any time. Keep a counter so HBAs only see begin/end once.
1687      */
1688     if (bus->drain_count++ == 0) {
1689         trace_scsi_bus_drained_begin(bus, sdev);
1690         if (bus->info->drained_begin) {
1691             bus->info->drained_begin(bus);
1692         }
1693     }
1694 }
1695 
1696 void scsi_device_drained_end(SCSIDevice *sdev)
1697 {
1698     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, sdev->qdev.parent_bus);
1699     if (!bus) {
1700         return;
1701     }
1702 
1703     assert(qemu_get_current_aio_context() == qemu_get_aio_context());
1704     assert(bus->drain_count > 0);
1705 
1706     if (bus->drain_count-- == 1) {
1707         trace_scsi_bus_drained_end(bus, sdev);
1708         if (bus->info->drained_end) {
1709             bus->info->drained_end(bus);
1710         }
1711     }
1712 }
1713 
1714 static char *scsibus_get_dev_path(DeviceState *dev)
1715 {
1716     SCSIDevice *d = SCSI_DEVICE(dev);
1717     DeviceState *hba = dev->parent_bus->parent;
1718     char *id;
1719     char *path;
1720 
1721     id = qdev_get_dev_path(hba);
1722     if (id) {
1723         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1724     } else {
1725         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1726     }
1727     g_free(id);
1728     return path;
1729 }
1730 
1731 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1732 {
1733     SCSIDevice *d = SCSI_DEVICE(dev);
1734     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1735                            qdev_fw_name(dev), d->id, d->lun);
1736 }
1737 
1738 /* SCSI request list.  For simplicity, pv points to the whole device */
1739 
1740 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1741                              const VMStateField *field, JSONWriter *vmdesc)
1742 {
1743     SCSIDevice *s = pv;
1744     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1745     SCSIRequest *req;
1746 
1747     QTAILQ_FOREACH(req, &s->requests, next) {
1748         assert(!req->io_canceled);
1749         assert(req->status == -1 && req->host_status == -1);
1750         assert(req->enqueued);
1751 
1752         qemu_put_sbyte(f, req->retry ? 1 : 2);
1753         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1754         qemu_put_be32s(f, &req->tag);
1755         qemu_put_be32s(f, &req->lun);
1756         if (bus->info->save_request) {
1757             bus->info->save_request(f, req);
1758         }
1759         if (req->ops->save_request) {
1760             req->ops->save_request(f, req);
1761         }
1762     }
1763     qemu_put_sbyte(f, 0);
1764 
1765     return 0;
1766 }
1767 
1768 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1769                              const VMStateField *field)
1770 {
1771     SCSIDevice *s = pv;
1772     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1773     int8_t sbyte;
1774 
1775     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1776         uint8_t buf[SCSI_CMD_BUF_SIZE];
1777         uint32_t tag;
1778         uint32_t lun;
1779         SCSIRequest *req;
1780 
1781         qemu_get_buffer(f, buf, sizeof(buf));
1782         qemu_get_be32s(f, &tag);
1783         qemu_get_be32s(f, &lun);
1784         /*
1785          * A too-short CDB would have been rejected by scsi_req_new, so just use
1786          * SCSI_CMD_BUF_SIZE as the CDB length.
1787          */
1788         req = scsi_req_new(s, tag, lun, buf, sizeof(buf), NULL);
1789         req->retry = (sbyte == 1);
1790         if (bus->info->load_request) {
1791             req->hba_private = bus->info->load_request(f, req);
1792         }
1793         if (req->ops->load_request) {
1794             req->ops->load_request(f, req);
1795         }
1796 
1797         /* Just restart it later.  */
1798         scsi_req_enqueue_internal(req);
1799 
1800         /* At this point, the request will be kept alive by the reference
1801          * added by scsi_req_enqueue_internal, so we can release our reference.
1802          * The HBA of course will add its own reference in the load_request
1803          * callback if it needs to hold on the SCSIRequest.
1804          */
1805         scsi_req_unref(req);
1806     }
1807 
1808     return 0;
1809 }
1810 
1811 static const VMStateInfo vmstate_info_scsi_requests = {
1812     .name = "scsi-requests",
1813     .get  = get_scsi_requests,
1814     .put  = put_scsi_requests,
1815 };
1816 
1817 static bool scsi_sense_state_needed(void *opaque)
1818 {
1819     SCSIDevice *s = opaque;
1820 
1821     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1822 }
1823 
1824 static const VMStateDescription vmstate_scsi_sense_state = {
1825     .name = "SCSIDevice/sense",
1826     .version_id = 1,
1827     .minimum_version_id = 1,
1828     .needed = scsi_sense_state_needed,
1829     .fields = (VMStateField[]) {
1830         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1831                                 SCSI_SENSE_BUF_SIZE_OLD,
1832                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1833         VMSTATE_END_OF_LIST()
1834     }
1835 };
1836 
1837 const VMStateDescription vmstate_scsi_device = {
1838     .name = "SCSIDevice",
1839     .version_id = 1,
1840     .minimum_version_id = 1,
1841     .fields = (VMStateField[]) {
1842         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1843         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1844         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1845         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1846         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1847         VMSTATE_UINT32(sense_len, SCSIDevice),
1848         {
1849             .name         = "requests",
1850             .version_id   = 0,
1851             .field_exists = NULL,
1852             .size         = 0,   /* ouch */
1853             .info         = &vmstate_info_scsi_requests,
1854             .flags        = VMS_SINGLE,
1855             .offset       = 0,
1856         },
1857         VMSTATE_END_OF_LIST()
1858     },
1859     .subsections = (const VMStateDescription*[]) {
1860         &vmstate_scsi_sense_state,
1861         NULL
1862     }
1863 };
1864 
1865 static Property scsi_props[] = {
1866     DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
1867     DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
1868     DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
1869     DEFINE_PROP_END_OF_LIST(),
1870 };
1871 
1872 static void scsi_device_class_init(ObjectClass *klass, void *data)
1873 {
1874     DeviceClass *k = DEVICE_CLASS(klass);
1875     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1876     k->bus_type  = TYPE_SCSI_BUS;
1877     k->realize   = scsi_qdev_realize;
1878     k->unrealize = scsi_qdev_unrealize;
1879     device_class_set_props(k, scsi_props);
1880 }
1881 
1882 static void scsi_dev_instance_init(Object *obj)
1883 {
1884     DeviceState *dev = DEVICE(obj);
1885     SCSIDevice *s = SCSI_DEVICE(dev);
1886 
1887     device_add_bootindex_property(obj, &s->conf.bootindex,
1888                                   "bootindex", NULL,
1889                                   &s->qdev);
1890 }
1891 
1892 static const TypeInfo scsi_device_type_info = {
1893     .name = TYPE_SCSI_DEVICE,
1894     .parent = TYPE_DEVICE,
1895     .instance_size = sizeof(SCSIDevice),
1896     .abstract = true,
1897     .class_size = sizeof(SCSIDeviceClass),
1898     .class_init = scsi_device_class_init,
1899     .instance_init = scsi_dev_instance_init,
1900 };
1901 
1902 static void scsi_bus_class_init(ObjectClass *klass, void *data)
1903 {
1904     BusClass *k = BUS_CLASS(klass);
1905     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1906 
1907     k->get_dev_path = scsibus_get_dev_path;
1908     k->get_fw_dev_path = scsibus_get_fw_dev_path;
1909     k->check_address = scsi_bus_check_address;
1910     hc->unplug = qdev_simple_device_unplug_cb;
1911 }
1912 
1913 static const TypeInfo scsi_bus_info = {
1914     .name = TYPE_SCSI_BUS,
1915     .parent = TYPE_BUS,
1916     .instance_size = sizeof(SCSIBus),
1917     .class_init = scsi_bus_class_init,
1918     .interfaces = (InterfaceInfo[]) {
1919         { TYPE_HOTPLUG_HANDLER },
1920         { }
1921     }
1922 };
1923 
1924 static void scsi_register_types(void)
1925 {
1926     type_register_static(&scsi_bus_info);
1927     type_register_static(&scsi_device_type_info);
1928 }
1929 
1930 type_init(scsi_register_types)
1931