xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision 7c08eefc)
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 /*
89  * Invoke @fn() for each enqueued request in device @s. Must be called from the
90  * main loop thread while the guest is stopped. This is only suitable for
91  * vmstate ->put(), use scsi_device_for_each_req_async() for other cases.
92  */
93 static void scsi_device_for_each_req_sync(SCSIDevice *s,
94                                           void (*fn)(SCSIRequest *, void *),
95                                           void *opaque)
96 {
97     SCSIRequest *req;
98     SCSIRequest *next_req;
99 
100     assert(!runstate_is_running());
101     assert(qemu_in_main_thread());
102 
103     QTAILQ_FOREACH_SAFE(req, &s->requests, next, next_req) {
104         fn(req, opaque);
105     }
106 }
107 
108 typedef struct {
109     SCSIDevice *s;
110     void (*fn)(SCSIRequest *, void *);
111     void *fn_opaque;
112 } SCSIDeviceForEachReqAsyncData;
113 
114 static void scsi_device_for_each_req_async_bh(void *opaque)
115 {
116     g_autofree SCSIDeviceForEachReqAsyncData *data = opaque;
117     SCSIDevice *s = data->s;
118     AioContext *ctx;
119     SCSIRequest *req;
120     SCSIRequest *next;
121 
122     /*
123      * The BB cannot have changed contexts between this BH being scheduled and
124      * now: BBs' AioContexts, when they have a node attached, can only be
125      * changed via bdrv_try_change_aio_context(), in a drained section.  While
126      * we have the in-flight counter incremented, that drain must block.
127      */
128     ctx = blk_get_aio_context(s->conf.blk);
129     assert(ctx == qemu_get_current_aio_context());
130 
131     QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
132         data->fn(req, data->fn_opaque);
133     }
134 
135     /* Drop the reference taken by scsi_device_for_each_req_async() */
136     object_unref(OBJECT(s));
137 
138     /* Paired with blk_inc_in_flight() in scsi_device_for_each_req_async() */
139     blk_dec_in_flight(s->conf.blk);
140 }
141 
142 /*
143  * Schedule @fn() to be invoked for each enqueued request in device @s. @fn()
144  * runs in the AioContext that is executing the request.
145  * Keeps the BlockBackend's in-flight counter incremented until everything is
146  * done, so draining it will settle all scheduled @fn() calls.
147  */
148 static void scsi_device_for_each_req_async(SCSIDevice *s,
149                                            void (*fn)(SCSIRequest *, void *),
150                                            void *opaque)
151 {
152     assert(qemu_in_main_thread());
153 
154     SCSIDeviceForEachReqAsyncData *data =
155         g_new(SCSIDeviceForEachReqAsyncData, 1);
156 
157     data->s = s;
158     data->fn = fn;
159     data->fn_opaque = opaque;
160 
161     /*
162      * Hold a reference to the SCSIDevice until
163      * scsi_device_for_each_req_async_bh() finishes.
164      */
165     object_ref(OBJECT(s));
166 
167     /* Paired with blk_dec_in_flight() in scsi_device_for_each_req_async_bh() */
168     blk_inc_in_flight(s->conf.blk);
169     aio_bh_schedule_oneshot(blk_get_aio_context(s->conf.blk),
170                             scsi_device_for_each_req_async_bh,
171                             data);
172 }
173 
174 static void scsi_device_realize(SCSIDevice *s, Error **errp)
175 {
176     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
177     if (sc->realize) {
178         sc->realize(s, errp);
179     }
180 }
181 
182 static void scsi_device_unrealize(SCSIDevice *s)
183 {
184     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
185     if (sc->unrealize) {
186         sc->unrealize(s);
187     }
188 }
189 
190 int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
191                        size_t buf_len, void *hba_private)
192 {
193     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
194     int rc;
195 
196     assert(cmd->len == 0);
197     rc = scsi_req_parse_cdb(dev, cmd, buf, buf_len);
198     if (bus->info->parse_cdb) {
199         rc = bus->info->parse_cdb(dev, cmd, buf, buf_len, hba_private);
200     }
201     return rc;
202 }
203 
204 static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
205                                           uint8_t *buf, void *hba_private)
206 {
207     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
208     if (sc->alloc_req) {
209         return sc->alloc_req(s, tag, lun, buf, hba_private);
210     }
211 
212     return NULL;
213 }
214 
215 void scsi_device_unit_attention_reported(SCSIDevice *s)
216 {
217     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
218     if (sc->unit_attention_reported) {
219         sc->unit_attention_reported(s);
220     }
221 }
222 
223 /* Create a scsi bus, and attach devices to it.  */
224 void scsi_bus_init_named(SCSIBus *bus, size_t bus_size, DeviceState *host,
225                          const SCSIBusInfo *info, const char *bus_name)
226 {
227     qbus_init(bus, bus_size, TYPE_SCSI_BUS, host, bus_name);
228     bus->busnr = next_scsi_bus++;
229     bus->info = info;
230     qbus_set_bus_hotplug_handler(BUS(bus));
231 }
232 
233 void scsi_req_retry(SCSIRequest *req)
234 {
235     req->retry = true;
236 }
237 
238 /* Called in the AioContext that is executing the request */
239 static void scsi_dma_restart_req(SCSIRequest *req, void *opaque)
240 {
241     scsi_req_ref(req);
242     if (req->retry) {
243         req->retry = false;
244         switch (req->cmd.mode) {
245             case SCSI_XFER_FROM_DEV:
246             case SCSI_XFER_TO_DEV:
247                 scsi_req_continue(req);
248                 break;
249             case SCSI_XFER_NONE:
250                 scsi_req_dequeue(req);
251                 scsi_req_enqueue(req);
252                 break;
253         }
254     }
255     scsi_req_unref(req);
256 }
257 
258 static void scsi_dma_restart_cb(void *opaque, bool running, RunState state)
259 {
260     SCSIDevice *s = opaque;
261 
262     assert(qemu_in_main_thread());
263 
264     if (!running) {
265         return;
266     }
267 
268     scsi_device_for_each_req_async(s, scsi_dma_restart_req, NULL);
269 }
270 
271 static bool scsi_bus_is_address_free(SCSIBus *bus,
272                                      int channel, int target, int lun,
273                                      SCSIDevice **p_dev)
274 {
275     SCSIDevice *d;
276 
277     RCU_READ_LOCK_GUARD();
278     d = do_scsi_device_find(bus, channel, target, lun, true);
279     if (d && d->lun == lun) {
280         if (p_dev) {
281             *p_dev = d;
282         }
283         return false;
284     }
285     if (p_dev) {
286         *p_dev = NULL;
287     }
288     return true;
289 }
290 
291 static bool scsi_bus_check_address(BusState *qbus, DeviceState *qdev, Error **errp)
292 {
293     SCSIDevice *dev = SCSI_DEVICE(qdev);
294     SCSIBus *bus = SCSI_BUS(qbus);
295 
296     if (dev->channel > bus->info->max_channel) {
297         error_setg(errp, "bad scsi channel id: %d", dev->channel);
298         return false;
299     }
300     if (dev->id != -1 && dev->id > bus->info->max_target) {
301         error_setg(errp, "bad scsi device id: %d", dev->id);
302         return false;
303     }
304     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
305         error_setg(errp, "bad scsi device lun: %d", dev->lun);
306         return false;
307     }
308 
309     if (dev->id != -1 && dev->lun != -1) {
310         SCSIDevice *d;
311         if (!scsi_bus_is_address_free(bus, dev->channel, dev->id, dev->lun, &d)) {
312             error_setg(errp, "lun already used by '%s'", d->qdev.id);
313             return false;
314         }
315     }
316 
317     return true;
318 }
319 
320 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
321 {
322     SCSIDevice *dev = SCSI_DEVICE(qdev);
323     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
324     bool is_free;
325     Error *local_err = NULL;
326 
327     if (dev->id == -1) {
328         int id = -1;
329         if (dev->lun == -1) {
330             dev->lun = 0;
331         }
332         do {
333             is_free = scsi_bus_is_address_free(bus, dev->channel, ++id, dev->lun, NULL);
334         } while (!is_free && id < bus->info->max_target);
335         if (!is_free) {
336             error_setg(errp, "no free target");
337             return;
338         }
339         dev->id = id;
340     } else if (dev->lun == -1) {
341         int lun = -1;
342         do {
343             is_free = scsi_bus_is_address_free(bus, dev->channel, dev->id, ++lun, NULL);
344         } while (!is_free && lun < bus->info->max_lun);
345         if (!is_free) {
346             error_setg(errp, "no free lun");
347             return;
348         }
349         dev->lun = lun;
350     }
351 
352     QTAILQ_INIT(&dev->requests);
353     scsi_device_realize(dev, &local_err);
354     if (local_err) {
355         error_propagate(errp, local_err);
356         return;
357     }
358     dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
359             scsi_dma_restart_cb, dev);
360 }
361 
362 static void scsi_qdev_unrealize(DeviceState *qdev)
363 {
364     SCSIDevice *dev = SCSI_DEVICE(qdev);
365 
366     if (dev->vmsentry) {
367         qemu_del_vm_change_state_handler(dev->vmsentry);
368     }
369 
370     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
371 
372     scsi_device_unrealize(dev);
373 
374     blockdev_mark_auto_del(dev->conf.blk);
375 }
376 
377 /* handle legacy '-drive if=scsi,...' cmd line args */
378 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
379                                       int unit, bool removable, BlockConf *conf,
380                                       const char *serial, Error **errp)
381 {
382     const char *driver;
383     char *name;
384     DeviceState *dev;
385     SCSIDevice *s;
386     DriveInfo *dinfo;
387 
388     if (blk_is_sg(blk)) {
389         driver = "scsi-generic";
390     } else {
391         dinfo = blk_legacy_dinfo(blk);
392         if (dinfo && dinfo->media_cd) {
393             driver = "scsi-cd";
394         } else {
395             driver = "scsi-hd";
396         }
397     }
398     dev = qdev_new(driver);
399     name = g_strdup_printf("legacy[%d]", unit);
400     object_property_add_child(OBJECT(bus), name, OBJECT(dev));
401     g_free(name);
402 
403     s = SCSI_DEVICE(dev);
404     s->conf = *conf;
405 
406     qdev_prop_set_uint32(dev, "scsi-id", unit);
407     if (object_property_find(OBJECT(dev), "removable")) {
408         qdev_prop_set_bit(dev, "removable", removable);
409     }
410     if (serial && object_property_find(OBJECT(dev), "serial")) {
411         qdev_prop_set_string(dev, "serial", serial);
412     }
413     if (!qdev_prop_set_drive_err(dev, "drive", blk, errp)) {
414         object_unparent(OBJECT(dev));
415         return NULL;
416     }
417 
418     if (!qdev_realize_and_unref(dev, &bus->qbus, errp)) {
419         object_unparent(OBJECT(dev));
420         return NULL;
421     }
422     return s;
423 }
424 
425 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
426 {
427     Location loc;
428     DriveInfo *dinfo;
429     int unit;
430     BlockConf conf = {
431         .bootindex = -1,
432         .share_rw = false,
433         .rerror = BLOCKDEV_ON_ERROR_AUTO,
434         .werror = BLOCKDEV_ON_ERROR_AUTO,
435     };
436 
437     loc_push_none(&loc);
438     for (unit = 0; unit <= bus->info->max_target; unit++) {
439         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
440         if (dinfo == NULL) {
441             continue;
442         }
443         qemu_opts_loc_restore(dinfo->opts);
444         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
445                                   unit, false, &conf, NULL, &error_fatal);
446     }
447     loc_pop(&loc);
448 }
449 
450 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
451 {
452     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
453     scsi_req_complete(req, CHECK_CONDITION);
454     return 0;
455 }
456 
457 static const struct SCSIReqOps reqops_invalid_field = {
458     .size         = sizeof(SCSIRequest),
459     .send_command = scsi_invalid_field
460 };
461 
462 /* SCSIReqOps implementation for invalid commands.  */
463 
464 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
465 {
466     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
467     scsi_req_complete(req, CHECK_CONDITION);
468     return 0;
469 }
470 
471 static const struct SCSIReqOps reqops_invalid_opcode = {
472     .size         = sizeof(SCSIRequest),
473     .send_command = scsi_invalid_command
474 };
475 
476 /* SCSIReqOps implementation for unit attention conditions.  */
477 
478 static void scsi_fetch_unit_attention_sense(SCSIRequest *req)
479 {
480     SCSISense *ua = NULL;
481 
482     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
483         ua = &req->dev->unit_attention;
484     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
485         ua = &req->bus->unit_attention;
486     }
487 
488     /*
489      * Fetch the unit attention sense immediately so that another
490      * scsi_req_new does not use reqops_unit_attention.
491      */
492     if (ua) {
493         scsi_req_build_sense(req, *ua);
494         *ua = SENSE_CODE(NO_SENSE);
495     }
496 }
497 
498 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
499 {
500     scsi_req_complete(req, CHECK_CONDITION);
501     return 0;
502 }
503 
504 static const struct SCSIReqOps reqops_unit_attention = {
505     .size         = sizeof(SCSIRequest),
506     .init_req     = scsi_fetch_unit_attention_sense,
507     .send_command = scsi_unit_attention
508 };
509 
510 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
511    an invalid LUN.  */
512 
513 typedef struct SCSITargetReq SCSITargetReq;
514 
515 struct SCSITargetReq {
516     SCSIRequest req;
517     int len;
518     uint8_t *buf;
519     int buf_len;
520 };
521 
522 static void store_lun(uint8_t *outbuf, int lun)
523 {
524     if (lun < 256) {
525         /* Simple logical unit addressing method*/
526         outbuf[0] = 0;
527         outbuf[1] = lun;
528     } else {
529         /* Flat space addressing method */
530         outbuf[0] = 0x40 | (lun >> 8);
531         outbuf[1] = (lun & 255);
532     }
533 }
534 
535 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
536 {
537     BusChild *kid;
538     int channel, id;
539     uint8_t tmp[8] = {0};
540     int len = 0;
541     GByteArray *buf;
542 
543     if (r->req.cmd.xfer < 16) {
544         return false;
545     }
546     if (r->req.cmd.buf[2] > 2) {
547         return false;
548     }
549 
550     /* reserve space for 63 LUNs*/
551     buf = g_byte_array_sized_new(512);
552 
553     channel = r->req.dev->channel;
554     id = r->req.dev->id;
555 
556     /* add size (will be updated later to correct value */
557     g_byte_array_append(buf, tmp, 8);
558     len += 8;
559 
560     /* add LUN0 */
561     g_byte_array_append(buf, tmp, 8);
562     len += 8;
563 
564     WITH_RCU_READ_LOCK_GUARD() {
565         QTAILQ_FOREACH_RCU(kid, &r->req.bus->qbus.children, sibling) {
566             DeviceState *qdev = kid->child;
567             SCSIDevice *dev = SCSI_DEVICE(qdev);
568 
569             if (dev->channel == channel && dev->id == id && dev->lun != 0 &&
570                 qdev_is_realized(&dev->qdev)) {
571                 store_lun(tmp, dev->lun);
572                 g_byte_array_append(buf, tmp, 8);
573                 len += 8;
574             }
575         }
576     }
577 
578     r->buf_len = len;
579     r->buf = g_byte_array_free(buf, FALSE);
580     r->len = MIN(len, r->req.cmd.xfer & ~7);
581 
582     /* store the LUN list length */
583     stl_be_p(&r->buf[0], len - 8);
584 
585     /*
586      * If a REPORT LUNS command enters the enabled command state, [...]
587      * the device server shall clear any pending unit attention condition
588      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
589      */
590     scsi_clear_reported_luns_changed(&r->req);
591 
592     return true;
593 }
594 
595 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
596 {
597     assert(r->req.dev->lun != r->req.lun);
598 
599     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
600 
601     if (r->req.cmd.buf[1] & 0x2) {
602         /* Command support data - optional, not implemented */
603         return false;
604     }
605 
606     if (r->req.cmd.buf[1] & 0x1) {
607         /* Vital product data */
608         uint8_t page_code = r->req.cmd.buf[2];
609         r->buf[r->len++] = page_code ; /* this page */
610         r->buf[r->len++] = 0x00;
611 
612         switch (page_code) {
613         case 0x00: /* Supported page codes, mandatory */
614         {
615             int pages;
616             pages = r->len++;
617             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
618             r->buf[pages] = r->len - pages - 1; /* number of pages */
619             break;
620         }
621         default:
622             return false;
623         }
624         /* done with EVPD */
625         assert(r->len < r->buf_len);
626         r->len = MIN(r->req.cmd.xfer, r->len);
627         return true;
628     }
629 
630     /* Standard INQUIRY data */
631     if (r->req.cmd.buf[2] != 0) {
632         return false;
633     }
634 
635     /* PAGE CODE == 0 */
636     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
637     memset(r->buf, 0, r->len);
638     if (r->req.lun != 0) {
639         r->buf[0] = TYPE_NO_LUN;
640     } else {
641         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
642         r->buf[2] = 5; /* Version */
643         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
644         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
645         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
646         memcpy(&r->buf[8], "QEMU    ", 8);
647         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
648         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
649     }
650     return true;
651 }
652 
653 static size_t scsi_sense_len(SCSIRequest *req)
654 {
655     if (req->dev->type == TYPE_SCANNER)
656         return SCSI_SENSE_LEN_SCANNER;
657     else
658         return SCSI_SENSE_LEN;
659 }
660 
661 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
662 {
663     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
664     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
665 
666     if (req->lun != 0 &&
667         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
668         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
669         scsi_req_complete(req, CHECK_CONDITION);
670         return 0;
671     }
672     switch (buf[0]) {
673     case REPORT_LUNS:
674         if (!scsi_target_emulate_report_luns(r)) {
675             goto illegal_request;
676         }
677         break;
678     case INQUIRY:
679         if (!scsi_target_emulate_inquiry(r)) {
680             goto illegal_request;
681         }
682         break;
683     case REQUEST_SENSE:
684         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
685         if (req->lun != 0) {
686             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
687 
688             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
689                                           sense, fixed_sense);
690         } else {
691             r->len = scsi_device_get_sense(r->req.dev, r->buf,
692                                            MIN(req->cmd.xfer, r->buf_len),
693                                            fixed_sense);
694         }
695         if (r->req.dev->sense_is_ua) {
696             scsi_device_unit_attention_reported(req->dev);
697             r->req.dev->sense_len = 0;
698             r->req.dev->sense_is_ua = false;
699         }
700         break;
701     case TEST_UNIT_READY:
702         break;
703     default:
704         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
705         scsi_req_complete(req, CHECK_CONDITION);
706         return 0;
707     illegal_request:
708         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
709         scsi_req_complete(req, CHECK_CONDITION);
710         return 0;
711     }
712 
713     if (!r->len) {
714         scsi_req_complete(req, GOOD);
715     }
716     return r->len;
717 }
718 
719 static void scsi_target_read_data(SCSIRequest *req)
720 {
721     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
722     uint32_t n;
723 
724     n = r->len;
725     if (n > 0) {
726         r->len = 0;
727         scsi_req_data(&r->req, n);
728     } else {
729         scsi_req_complete(&r->req, GOOD);
730     }
731 }
732 
733 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
734 {
735     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
736 
737     return r->buf;
738 }
739 
740 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
741 {
742     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
743 
744     r->buf = g_malloc(len);
745     r->buf_len = len;
746 
747     return r->buf;
748 }
749 
750 static void scsi_target_free_buf(SCSIRequest *req)
751 {
752     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
753 
754     g_free(r->buf);
755 }
756 
757 static const struct SCSIReqOps reqops_target_command = {
758     .size         = sizeof(SCSITargetReq),
759     .send_command = scsi_target_send_command,
760     .read_data    = scsi_target_read_data,
761     .get_buf      = scsi_target_get_buf,
762     .free_req     = scsi_target_free_buf,
763 };
764 
765 
766 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
767                             uint32_t tag, uint32_t lun, void *hba_private)
768 {
769     SCSIRequest *req;
770     SCSIBus *bus = scsi_bus_from_device(d);
771     BusState *qbus = BUS(bus);
772     const int memset_off = offsetof(SCSIRequest, sense)
773                            + sizeof(req->sense);
774 
775     req = g_malloc(reqops->size);
776     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
777     req->refcount = 1;
778     req->bus = bus;
779     req->dev = d;
780     req->tag = tag;
781     req->lun = lun;
782     req->hba_private = hba_private;
783     req->status = -1;
784     req->host_status = -1;
785     req->ops = reqops;
786     object_ref(OBJECT(d));
787     object_ref(OBJECT(qbus->parent));
788     notifier_list_init(&req->cancel_notifiers);
789 
790     if (reqops->init_req) {
791         reqops->init_req(req);
792     }
793 
794     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
795     return req;
796 }
797 
798 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
799                           uint8_t *buf, size_t buf_len, void *hba_private)
800 {
801     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
802     const SCSIReqOps *ops;
803     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
804     SCSIRequest *req;
805     SCSICommand cmd = { .len = 0 };
806     int ret;
807 
808     if (buf_len == 0) {
809         trace_scsi_req_parse_bad(d->id, lun, tag, 0);
810         goto invalid_opcode;
811     }
812 
813     if ((d->unit_attention.key == UNIT_ATTENTION ||
814          bus->unit_attention.key == UNIT_ATTENTION) &&
815         (buf[0] != INQUIRY &&
816          buf[0] != REPORT_LUNS &&
817          buf[0] != GET_CONFIGURATION &&
818          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
819 
820          /*
821           * If we already have a pending unit attention condition,
822           * report this one before triggering another one.
823           */
824          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
825         ops = &reqops_unit_attention;
826     } else if (lun != d->lun ||
827                buf[0] == REPORT_LUNS ||
828                (buf[0] == REQUEST_SENSE && d->sense_len)) {
829         ops = &reqops_target_command;
830     } else {
831         ops = NULL;
832     }
833 
834     if (ops != NULL || !sc->parse_cdb) {
835         ret = scsi_req_parse_cdb(d, &cmd, buf, buf_len);
836     } else {
837         ret = sc->parse_cdb(d, &cmd, buf, buf_len, hba_private);
838     }
839 
840     if (ret != 0) {
841         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
842 invalid_opcode:
843         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
844     } else {
845         assert(cmd.len != 0);
846         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
847                               cmd.mode, cmd.xfer);
848         if (cmd.lba != -1) {
849             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
850                                       cmd.lba);
851         }
852 
853         if (cmd.xfer > INT32_MAX) {
854             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
855         } else if (ops) {
856             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
857         } else {
858             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
859         }
860     }
861 
862     req->cmd = cmd;
863     req->residual = req->cmd.xfer;
864 
865     switch (buf[0]) {
866     case INQUIRY:
867         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
868         break;
869     case TEST_UNIT_READY:
870         trace_scsi_test_unit_ready(d->id, lun, tag);
871         break;
872     case REPORT_LUNS:
873         trace_scsi_report_luns(d->id, lun, tag);
874         break;
875     case REQUEST_SENSE:
876         trace_scsi_request_sense(d->id, lun, tag);
877         break;
878     default:
879         break;
880     }
881 
882     return req;
883 }
884 
885 uint8_t *scsi_req_get_buf(SCSIRequest *req)
886 {
887     return req->ops->get_buf(req);
888 }
889 
890 static void scsi_clear_reported_luns_changed(SCSIRequest *req)
891 {
892     SCSISense *ua;
893 
894     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
895         ua = &req->dev->unit_attention;
896     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
897         ua = &req->bus->unit_attention;
898     } else {
899         return;
900     }
901 
902     if (ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
903         ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq) {
904         *ua = SENSE_CODE(NO_SENSE);
905     }
906 }
907 
908 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
909 {
910     int ret;
911 
912     assert(len >= 14);
913     if (!req->sense_len) {
914         return 0;
915     }
916 
917     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
918 
919     /*
920      * FIXME: clearing unit attention conditions upon autosense should be done
921      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
922      * (SAM-5, 5.14).
923      *
924      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
925      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
926      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
927      */
928     if (req->dev->sense_is_ua) {
929         scsi_device_unit_attention_reported(req->dev);
930         req->dev->sense_len = 0;
931         req->dev->sense_is_ua = false;
932     }
933     return ret;
934 }
935 
936 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
937 {
938     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
939 }
940 
941 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
942 {
943     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
944                                sense.key, sense.asc, sense.ascq);
945     req->sense_len = scsi_build_sense(req->sense, sense);
946 }
947 
948 static void scsi_req_enqueue_internal(SCSIRequest *req)
949 {
950     assert(!req->enqueued);
951     scsi_req_ref(req);
952     if (req->bus->info->get_sg_list) {
953         req->sg = req->bus->info->get_sg_list(req);
954     } else {
955         req->sg = NULL;
956     }
957     req->enqueued = true;
958     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
959 }
960 
961 int32_t scsi_req_enqueue(SCSIRequest *req)
962 {
963     int32_t rc;
964 
965     assert(!req->retry);
966     scsi_req_enqueue_internal(req);
967     scsi_req_ref(req);
968     rc = req->ops->send_command(req, req->cmd.buf);
969     scsi_req_unref(req);
970     return rc;
971 }
972 
973 static void scsi_req_dequeue(SCSIRequest *req)
974 {
975     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
976     req->retry = false;
977     if (req->enqueued) {
978         QTAILQ_REMOVE(&req->dev->requests, req, next);
979         req->enqueued = false;
980         scsi_req_unref(req);
981     }
982 }
983 
984 static int scsi_get_performance_length(int num_desc, int type, int data_type)
985 {
986     /* MMC-6, paragraph 6.7.  */
987     switch (type) {
988     case 0:
989         if ((data_type & 3) == 0) {
990             /* Each descriptor is as in Table 295 - Nominal performance.  */
991             return 16 * num_desc + 8;
992         } else {
993             /* Each descriptor is as in Table 296 - Exceptions.  */
994             return 6 * num_desc + 8;
995         }
996     case 1:
997     case 4:
998     case 5:
999         return 8 * num_desc + 8;
1000     case 2:
1001         return 2048 * num_desc + 8;
1002     case 3:
1003         return 16 * num_desc + 8;
1004     default:
1005         return 8;
1006     }
1007 }
1008 
1009 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
1010 {
1011     int byte_block = (buf[2] >> 2) & 0x1;
1012     int type = (buf[2] >> 4) & 0x1;
1013     int xfer_unit;
1014 
1015     if (byte_block) {
1016         if (type) {
1017             xfer_unit = dev->blocksize;
1018         } else {
1019             xfer_unit = 512;
1020         }
1021     } else {
1022         xfer_unit = 1;
1023     }
1024 
1025     return xfer_unit;
1026 }
1027 
1028 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
1029 {
1030     int length = buf[2] & 0x3;
1031     int xfer;
1032     int unit = ata_passthrough_xfer_unit(dev, buf);
1033 
1034     switch (length) {
1035     case 0:
1036     case 3: /* USB-specific.  */
1037     default:
1038         xfer = 0;
1039         break;
1040     case 1:
1041         xfer = buf[3];
1042         break;
1043     case 2:
1044         xfer = buf[4];
1045         break;
1046     }
1047 
1048     return xfer * unit;
1049 }
1050 
1051 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
1052 {
1053     int extend = buf[1] & 0x1;
1054     int length = buf[2] & 0x3;
1055     int xfer;
1056     int unit = ata_passthrough_xfer_unit(dev, buf);
1057 
1058     switch (length) {
1059     case 0:
1060     case 3: /* USB-specific.  */
1061     default:
1062         xfer = 0;
1063         break;
1064     case 1:
1065         xfer = buf[4];
1066         xfer |= (extend ? buf[3] << 8 : 0);
1067         break;
1068     case 2:
1069         xfer = buf[6];
1070         xfer |= (extend ? buf[5] << 8 : 0);
1071         break;
1072     }
1073 
1074     return xfer * unit;
1075 }
1076 
1077 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1078 {
1079     cmd->xfer = scsi_cdb_xfer(buf);
1080     switch (buf[0]) {
1081     case TEST_UNIT_READY:
1082     case REWIND:
1083     case START_STOP:
1084     case SET_CAPACITY:
1085     case WRITE_FILEMARKS:
1086     case WRITE_FILEMARKS_16:
1087     case SPACE:
1088     case RESERVE:
1089     case RELEASE:
1090     case ERASE:
1091     case ALLOW_MEDIUM_REMOVAL:
1092     case SEEK_10:
1093     case SYNCHRONIZE_CACHE:
1094     case SYNCHRONIZE_CACHE_16:
1095     case LOCATE_16:
1096     case LOCK_UNLOCK_CACHE:
1097     case SET_CD_SPEED:
1098     case SET_LIMITS:
1099     case WRITE_LONG_10:
1100     case UPDATE_BLOCK:
1101     case RESERVE_TRACK:
1102     case SET_READ_AHEAD:
1103     case PRE_FETCH:
1104     case PRE_FETCH_16:
1105     case ALLOW_OVERWRITE:
1106         cmd->xfer = 0;
1107         break;
1108     case VERIFY_10:
1109     case VERIFY_12:
1110     case VERIFY_16:
1111         if ((buf[1] & 2) == 0) {
1112             cmd->xfer = 0;
1113         } else if ((buf[1] & 4) != 0) {
1114             cmd->xfer = 1;
1115         }
1116         cmd->xfer *= dev->blocksize;
1117         break;
1118     case MODE_SENSE:
1119         break;
1120     case WRITE_SAME_10:
1121     case WRITE_SAME_16:
1122         cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
1123         break;
1124     case READ_CAPACITY_10:
1125         cmd->xfer = 8;
1126         break;
1127     case READ_BLOCK_LIMITS:
1128         cmd->xfer = 6;
1129         break;
1130     case SEND_VOLUME_TAG:
1131         /* GPCMD_SET_STREAMING from multimedia commands.  */
1132         if (dev->type == TYPE_ROM) {
1133             cmd->xfer = buf[10] | (buf[9] << 8);
1134         } else {
1135             cmd->xfer = buf[9] | (buf[8] << 8);
1136         }
1137         break;
1138     case WRITE_6:
1139         /* length 0 means 256 blocks */
1140         if (cmd->xfer == 0) {
1141             cmd->xfer = 256;
1142         }
1143         /* fall through */
1144     case WRITE_10:
1145     case WRITE_VERIFY_10:
1146     case WRITE_12:
1147     case WRITE_VERIFY_12:
1148     case WRITE_16:
1149     case WRITE_VERIFY_16:
1150         cmd->xfer *= dev->blocksize;
1151         break;
1152     case READ_6:
1153     case READ_REVERSE:
1154         /* length 0 means 256 blocks */
1155         if (cmd->xfer == 0) {
1156             cmd->xfer = 256;
1157         }
1158         /* fall through */
1159     case READ_10:
1160     case READ_12:
1161     case READ_16:
1162         cmd->xfer *= dev->blocksize;
1163         break;
1164     case FORMAT_UNIT:
1165         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1166          * for block devices are restricted to the header right now.  */
1167         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1168             cmd->xfer = 12;
1169         } else {
1170             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1171         }
1172         break;
1173     case INQUIRY:
1174     case RECEIVE_DIAGNOSTIC:
1175     case SEND_DIAGNOSTIC:
1176         cmd->xfer = buf[4] | (buf[3] << 8);
1177         break;
1178     case READ_CD:
1179     case READ_BUFFER:
1180     case WRITE_BUFFER:
1181     case SEND_CUE_SHEET:
1182         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1183         break;
1184     case PERSISTENT_RESERVE_OUT:
1185         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1186         break;
1187     case ERASE_12:
1188         if (dev->type == TYPE_ROM) {
1189             /* MMC command GET PERFORMANCE.  */
1190             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1191                                                     buf[10], buf[1] & 0x1f);
1192         }
1193         break;
1194     case MECHANISM_STATUS:
1195     case READ_DVD_STRUCTURE:
1196     case SEND_DVD_STRUCTURE:
1197     case MAINTENANCE_OUT:
1198     case MAINTENANCE_IN:
1199         if (dev->type == TYPE_ROM) {
1200             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1201             cmd->xfer = buf[9] | (buf[8] << 8);
1202         }
1203         break;
1204     case ATA_PASSTHROUGH_12:
1205         if (dev->type == TYPE_ROM) {
1206             /* BLANK command of MMC */
1207             cmd->xfer = 0;
1208         } else {
1209             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1210         }
1211         break;
1212     case ATA_PASSTHROUGH_16:
1213         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1214         break;
1215     }
1216     return 0;
1217 }
1218 
1219 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1220 {
1221     switch (buf[0]) {
1222     /* stream commands */
1223     case ERASE_12:
1224     case ERASE_16:
1225         cmd->xfer = 0;
1226         break;
1227     case READ_6:
1228     case READ_REVERSE:
1229     case RECOVER_BUFFERED_DATA:
1230     case WRITE_6:
1231         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1232         if (buf[1] & 0x01) { /* fixed */
1233             cmd->xfer *= dev->blocksize;
1234         }
1235         break;
1236     case READ_16:
1237     case READ_REVERSE_16:
1238     case VERIFY_16:
1239     case WRITE_16:
1240         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1241         if (buf[1] & 0x01) { /* fixed */
1242             cmd->xfer *= dev->blocksize;
1243         }
1244         break;
1245     case REWIND:
1246     case LOAD_UNLOAD:
1247         cmd->xfer = 0;
1248         break;
1249     case SPACE_16:
1250         cmd->xfer = buf[13] | (buf[12] << 8);
1251         break;
1252     case READ_POSITION:
1253         switch (buf[1] & 0x1f) /* operation code */ {
1254         case SHORT_FORM_BLOCK_ID:
1255         case SHORT_FORM_VENDOR_SPECIFIC:
1256             cmd->xfer = 20;
1257             break;
1258         case LONG_FORM:
1259             cmd->xfer = 32;
1260             break;
1261         case EXTENDED_FORM:
1262             cmd->xfer = buf[8] | (buf[7] << 8);
1263             break;
1264         default:
1265             return -1;
1266         }
1267 
1268         break;
1269     case FORMAT_UNIT:
1270         cmd->xfer = buf[4] | (buf[3] << 8);
1271         break;
1272     /* generic commands */
1273     default:
1274         return scsi_req_xfer(cmd, dev, buf);
1275     }
1276     return 0;
1277 }
1278 
1279 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1280 {
1281     switch (buf[0]) {
1282     /* medium changer commands */
1283     case EXCHANGE_MEDIUM:
1284     case INITIALIZE_ELEMENT_STATUS:
1285     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1286     case MOVE_MEDIUM:
1287     case POSITION_TO_ELEMENT:
1288         cmd->xfer = 0;
1289         break;
1290     case READ_ELEMENT_STATUS:
1291         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1292         break;
1293 
1294     /* generic commands */
1295     default:
1296         return scsi_req_xfer(cmd, dev, buf);
1297     }
1298     return 0;
1299 }
1300 
1301 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1302 {
1303     switch (buf[0]) {
1304     /* Scanner commands */
1305     case OBJECT_POSITION:
1306         cmd->xfer = 0;
1307         break;
1308     case SCAN:
1309         cmd->xfer = buf[4];
1310         break;
1311     case READ_10:
1312     case SEND:
1313     case GET_WINDOW:
1314     case SET_WINDOW:
1315         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1316         break;
1317     default:
1318         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1319         return scsi_req_xfer(cmd, dev, buf);
1320     }
1321 
1322     return 0;
1323 }
1324 
1325 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1326 {
1327     if (!cmd->xfer) {
1328         cmd->mode = SCSI_XFER_NONE;
1329         return;
1330     }
1331     switch (cmd->buf[0]) {
1332     case WRITE_6:
1333     case WRITE_10:
1334     case WRITE_VERIFY_10:
1335     case WRITE_12:
1336     case WRITE_VERIFY_12:
1337     case WRITE_16:
1338     case WRITE_VERIFY_16:
1339     case VERIFY_10:
1340     case VERIFY_12:
1341     case VERIFY_16:
1342     case COPY:
1343     case COPY_VERIFY:
1344     case COMPARE:
1345     case CHANGE_DEFINITION:
1346     case LOG_SELECT:
1347     case MODE_SELECT:
1348     case MODE_SELECT_10:
1349     case SEND_DIAGNOSTIC:
1350     case WRITE_BUFFER:
1351     case FORMAT_UNIT:
1352     case REASSIGN_BLOCKS:
1353     case SEARCH_EQUAL:
1354     case SEARCH_HIGH:
1355     case SEARCH_LOW:
1356     case UPDATE_BLOCK:
1357     case WRITE_LONG_10:
1358     case WRITE_SAME_10:
1359     case WRITE_SAME_16:
1360     case UNMAP:
1361     case SEARCH_HIGH_12:
1362     case SEARCH_EQUAL_12:
1363     case SEARCH_LOW_12:
1364     case MEDIUM_SCAN:
1365     case SEND_VOLUME_TAG:
1366     case SEND_CUE_SHEET:
1367     case SEND_DVD_STRUCTURE:
1368     case PERSISTENT_RESERVE_OUT:
1369     case MAINTENANCE_OUT:
1370     case SET_WINDOW:
1371     case SCAN:
1372         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1373          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1374          */
1375         cmd->mode = SCSI_XFER_TO_DEV;
1376         break;
1377     case ATA_PASSTHROUGH_12:
1378     case ATA_PASSTHROUGH_16:
1379         /* T_DIR */
1380         cmd->mode = (cmd->buf[2] & 0x8) ?
1381                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1382         break;
1383     default:
1384         cmd->mode = SCSI_XFER_FROM_DEV;
1385         break;
1386     }
1387 }
1388 
1389 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
1390                        size_t buf_len)
1391 {
1392     int rc;
1393     int len;
1394 
1395     cmd->lba = -1;
1396     len = scsi_cdb_length(buf);
1397     if (len < 0 || len > buf_len) {
1398         return -1;
1399     }
1400 
1401     cmd->len = len;
1402     switch (dev->type) {
1403     case TYPE_TAPE:
1404         rc = scsi_req_stream_xfer(cmd, dev, buf);
1405         break;
1406     case TYPE_MEDIUM_CHANGER:
1407         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1408         break;
1409     case TYPE_SCANNER:
1410         rc = scsi_req_scanner_length(cmd, dev, buf);
1411         break;
1412     default:
1413         rc = scsi_req_xfer(cmd, dev, buf);
1414         break;
1415     }
1416 
1417     if (rc != 0)
1418         return rc;
1419 
1420     memcpy(cmd->buf, buf, cmd->len);
1421     scsi_cmd_xfer_mode(cmd);
1422     cmd->lba = scsi_cmd_lba(cmd);
1423     return 0;
1424 }
1425 
1426 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1427 {
1428     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1429 
1430     scsi_device_set_ua(dev, sense);
1431     if (bus->info->change) {
1432         bus->info->change(bus, dev, sense);
1433     }
1434 }
1435 
1436 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1437 {
1438     assert(req->refcount > 0);
1439     req->refcount++;
1440     return req;
1441 }
1442 
1443 void scsi_req_unref(SCSIRequest *req)
1444 {
1445     assert(req->refcount > 0);
1446     if (--req->refcount == 0) {
1447         BusState *qbus = req->dev->qdev.parent_bus;
1448         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1449 
1450         if (bus->info->free_request && req->hba_private) {
1451             bus->info->free_request(bus, req->hba_private);
1452         }
1453         if (req->ops->free_req) {
1454             req->ops->free_req(req);
1455         }
1456         object_unref(OBJECT(req->dev));
1457         object_unref(OBJECT(qbus->parent));
1458         g_free(req);
1459     }
1460 }
1461 
1462 /* Tell the device that we finished processing this chunk of I/O.  It
1463    will start the next chunk or complete the command.  */
1464 void scsi_req_continue(SCSIRequest *req)
1465 {
1466     if (req->io_canceled) {
1467         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1468         return;
1469     }
1470     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1471     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1472         req->ops->write_data(req);
1473     } else {
1474         req->ops->read_data(req);
1475     }
1476 }
1477 
1478 /* Called by the devices when data is ready for the HBA.  The HBA should
1479    start a DMA operation to read or fill the device's data buffer.
1480    Once it completes, calling scsi_req_continue will restart I/O.  */
1481 void scsi_req_data(SCSIRequest *req, int len)
1482 {
1483     uint8_t *buf;
1484     if (req->io_canceled) {
1485         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1486         return;
1487     }
1488     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1489     assert(req->cmd.mode != SCSI_XFER_NONE);
1490     if (!req->sg) {
1491         req->residual -= len;
1492         req->bus->info->transfer_data(req, len);
1493         return;
1494     }
1495 
1496     /* If the device calls scsi_req_data and the HBA specified a
1497      * scatter/gather list, the transfer has to happen in a single
1498      * step.  */
1499     assert(!req->dma_started);
1500     req->dma_started = true;
1501 
1502     buf = scsi_req_get_buf(req);
1503     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1504         dma_buf_read(buf, len, &req->residual, req->sg,
1505                      MEMTXATTRS_UNSPECIFIED);
1506     } else {
1507         dma_buf_write(buf, len, &req->residual, req->sg,
1508                       MEMTXATTRS_UNSPECIFIED);
1509     }
1510     scsi_req_continue(req);
1511 }
1512 
1513 void scsi_req_print(SCSIRequest *req)
1514 {
1515     FILE *fp = stderr;
1516     int i;
1517 
1518     fprintf(fp, "[%s id=%d] %s",
1519             req->dev->qdev.parent_bus->name,
1520             req->dev->id,
1521             scsi_command_name(req->cmd.buf[0]));
1522     for (i = 1; i < req->cmd.len; i++) {
1523         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1524     }
1525     switch (req->cmd.mode) {
1526     case SCSI_XFER_NONE:
1527         fprintf(fp, " - none\n");
1528         break;
1529     case SCSI_XFER_FROM_DEV:
1530         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1531         break;
1532     case SCSI_XFER_TO_DEV:
1533         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1534         break;
1535     default:
1536         fprintf(fp, " - Oops\n");
1537         break;
1538     }
1539 }
1540 
1541 void scsi_req_complete_failed(SCSIRequest *req, int host_status)
1542 {
1543     SCSISense sense;
1544     int status;
1545 
1546     assert(req->status == -1 && req->host_status == -1);
1547     assert(req->ops != &reqops_unit_attention);
1548 
1549     if (!req->bus->info->fail) {
1550         status = scsi_sense_from_host_status(req->host_status, &sense);
1551         if (status == CHECK_CONDITION) {
1552             scsi_req_build_sense(req, sense);
1553         }
1554         scsi_req_complete(req, status);
1555         return;
1556     }
1557 
1558     req->host_status = host_status;
1559     scsi_req_ref(req);
1560     scsi_req_dequeue(req);
1561     req->bus->info->fail(req);
1562 
1563     /* Cancelled requests might end up being completed instead of cancelled */
1564     notifier_list_notify(&req->cancel_notifiers, req);
1565     scsi_req_unref(req);
1566 }
1567 
1568 void scsi_req_complete(SCSIRequest *req, int status)
1569 {
1570     assert(req->status == -1 && req->host_status == -1);
1571     req->status = status;
1572     req->host_status = SCSI_HOST_OK;
1573 
1574     assert(req->sense_len <= sizeof(req->sense));
1575     if (status == GOOD) {
1576         req->sense_len = 0;
1577     }
1578 
1579     if (req->sense_len) {
1580         memcpy(req->dev->sense, req->sense, req->sense_len);
1581         req->dev->sense_len = req->sense_len;
1582         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1583     } else {
1584         req->dev->sense_len = 0;
1585         req->dev->sense_is_ua = false;
1586     }
1587 
1588     scsi_req_ref(req);
1589     scsi_req_dequeue(req);
1590     req->bus->info->complete(req, req->residual);
1591 
1592     /* Cancelled requests might end up being completed instead of cancelled */
1593     notifier_list_notify(&req->cancel_notifiers, req);
1594     scsi_req_unref(req);
1595 }
1596 
1597 /* Called by the devices when the request is canceled. */
1598 void scsi_req_cancel_complete(SCSIRequest *req)
1599 {
1600     assert(req->io_canceled);
1601     if (req->bus->info->cancel) {
1602         req->bus->info->cancel(req);
1603     }
1604     notifier_list_notify(&req->cancel_notifiers, req);
1605     scsi_req_unref(req);
1606 }
1607 
1608 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1609  * notifier list, the bus will be notified the requests cancellation is
1610  * completed.
1611  * */
1612 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1613 {
1614     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1615     if (notifier) {
1616         notifier_list_add(&req->cancel_notifiers, notifier);
1617     }
1618     if (req->io_canceled) {
1619         /* A blk_aio_cancel_async is pending; when it finishes,
1620          * scsi_req_cancel_complete will be called and will
1621          * call the notifier we just added.  Just wait for that.
1622          */
1623         assert(req->aiocb);
1624         return;
1625     }
1626     /* Dropped in scsi_req_cancel_complete.  */
1627     scsi_req_ref(req);
1628     scsi_req_dequeue(req);
1629     req->io_canceled = true;
1630     if (req->aiocb) {
1631         blk_aio_cancel_async(req->aiocb);
1632     } else {
1633         scsi_req_cancel_complete(req);
1634     }
1635 }
1636 
1637 void scsi_req_cancel(SCSIRequest *req)
1638 {
1639     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1640     if (!req->enqueued) {
1641         return;
1642     }
1643     assert(!req->io_canceled);
1644     /* Dropped in scsi_req_cancel_complete.  */
1645     scsi_req_ref(req);
1646     scsi_req_dequeue(req);
1647     req->io_canceled = true;
1648     if (req->aiocb) {
1649         blk_aio_cancel(req->aiocb);
1650     } else {
1651         scsi_req_cancel_complete(req);
1652     }
1653 }
1654 
1655 static int scsi_ua_precedence(SCSISense sense)
1656 {
1657     if (sense.key != UNIT_ATTENTION) {
1658         return INT_MAX;
1659     }
1660     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1661         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1662         return 1;
1663     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1664         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1665         return 2;
1666     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1667         /* These two go with "all others". */
1668         ;
1669     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1670         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1671          * POWER ON OCCURRED = 1
1672          * SCSI BUS RESET OCCURRED = 2
1673          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1674          * I_T NEXUS LOSS OCCURRED = 7
1675          */
1676         return sense.ascq;
1677     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1678         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1679         return 8;
1680     }
1681     return (sense.asc << 8) | sense.ascq;
1682 }
1683 
1684 void scsi_bus_set_ua(SCSIBus *bus, SCSISense sense)
1685 {
1686     int prec1, prec2;
1687     if (sense.key != UNIT_ATTENTION) {
1688         return;
1689     }
1690 
1691     /*
1692      * Override a pre-existing unit attention condition, except for a more
1693      * important reset condition.
1694      */
1695     prec1 = scsi_ua_precedence(bus->unit_attention);
1696     prec2 = scsi_ua_precedence(sense);
1697     if (prec2 < prec1) {
1698         bus->unit_attention = sense;
1699     }
1700 }
1701 
1702 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1703 {
1704     int prec1, prec2;
1705     if (sense.key != UNIT_ATTENTION) {
1706         return;
1707     }
1708     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1709                              sense.asc, sense.ascq);
1710 
1711     /*
1712      * Override a pre-existing unit attention condition, except for a more
1713      * important reset condition.
1714     */
1715     prec1 = scsi_ua_precedence(sdev->unit_attention);
1716     prec2 = scsi_ua_precedence(sense);
1717     if (prec2 < prec1) {
1718         sdev->unit_attention = sense;
1719     }
1720 }
1721 
1722 static void scsi_device_purge_one_req(SCSIRequest *req, void *opaque)
1723 {
1724     scsi_req_cancel_async(req, NULL);
1725 }
1726 
1727 /**
1728  * Cancel all requests, and block until they are deleted.
1729  */
1730 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1731 {
1732     scsi_device_for_each_req_async(sdev, scsi_device_purge_one_req, NULL);
1733 
1734     /*
1735      * Await all the scsi_device_purge_one_req() calls scheduled by
1736      * scsi_device_for_each_req_async(), and all I/O requests that were
1737      * cancelled this way, but may still take a bit of time to settle.
1738      */
1739     blk_drain(sdev->conf.blk);
1740 
1741     scsi_device_set_ua(sdev, sense);
1742 }
1743 
1744 void scsi_device_drained_begin(SCSIDevice *sdev)
1745 {
1746     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, sdev->qdev.parent_bus);
1747     if (!bus) {
1748         return;
1749     }
1750 
1751     assert(qemu_get_current_aio_context() == qemu_get_aio_context());
1752     assert(bus->drain_count < INT_MAX);
1753 
1754     /*
1755      * Multiple BlockBackends can be on a SCSIBus and each may begin/end
1756      * draining at any time. Keep a counter so HBAs only see begin/end once.
1757      */
1758     if (bus->drain_count++ == 0) {
1759         trace_scsi_bus_drained_begin(bus, sdev);
1760         if (bus->info->drained_begin) {
1761             bus->info->drained_begin(bus);
1762         }
1763     }
1764 }
1765 
1766 void scsi_device_drained_end(SCSIDevice *sdev)
1767 {
1768     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, sdev->qdev.parent_bus);
1769     if (!bus) {
1770         return;
1771     }
1772 
1773     assert(qemu_get_current_aio_context() == qemu_get_aio_context());
1774     assert(bus->drain_count > 0);
1775 
1776     if (bus->drain_count-- == 1) {
1777         trace_scsi_bus_drained_end(bus, sdev);
1778         if (bus->info->drained_end) {
1779             bus->info->drained_end(bus);
1780         }
1781     }
1782 }
1783 
1784 static char *scsibus_get_dev_path(DeviceState *dev)
1785 {
1786     SCSIDevice *d = SCSI_DEVICE(dev);
1787     DeviceState *hba = dev->parent_bus->parent;
1788     char *id;
1789     char *path;
1790 
1791     id = qdev_get_dev_path(hba);
1792     if (id) {
1793         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1794     } else {
1795         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1796     }
1797     g_free(id);
1798     return path;
1799 }
1800 
1801 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1802 {
1803     SCSIDevice *d = SCSI_DEVICE(dev);
1804     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1805                            qdev_fw_name(dev), d->id, d->lun);
1806 }
1807 
1808 /* SCSI request list.  For simplicity, pv points to the whole device */
1809 
1810 static void put_scsi_req(SCSIRequest *req, void *opaque)
1811 {
1812     QEMUFile *f = opaque;
1813 
1814     assert(!req->io_canceled);
1815     assert(req->status == -1 && req->host_status == -1);
1816     assert(req->enqueued);
1817 
1818     qemu_put_sbyte(f, req->retry ? 1 : 2);
1819     qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1820     qemu_put_be32s(f, &req->tag);
1821     qemu_put_be32s(f, &req->lun);
1822     if (req->bus->info->save_request) {
1823         req->bus->info->save_request(f, req);
1824     }
1825     if (req->ops->save_request) {
1826         req->ops->save_request(f, req);
1827     }
1828 }
1829 
1830 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1831                              const VMStateField *field, JSONWriter *vmdesc)
1832 {
1833     SCSIDevice *s = pv;
1834 
1835     scsi_device_for_each_req_sync(s, put_scsi_req, f);
1836     qemu_put_sbyte(f, 0);
1837     return 0;
1838 }
1839 
1840 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1841                              const VMStateField *field)
1842 {
1843     SCSIDevice *s = pv;
1844     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1845     int8_t sbyte;
1846 
1847     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1848         uint8_t buf[SCSI_CMD_BUF_SIZE];
1849         uint32_t tag;
1850         uint32_t lun;
1851         SCSIRequest *req;
1852 
1853         qemu_get_buffer(f, buf, sizeof(buf));
1854         qemu_get_be32s(f, &tag);
1855         qemu_get_be32s(f, &lun);
1856         /*
1857          * A too-short CDB would have been rejected by scsi_req_new, so just use
1858          * SCSI_CMD_BUF_SIZE as the CDB length.
1859          */
1860         req = scsi_req_new(s, tag, lun, buf, sizeof(buf), NULL);
1861         req->retry = (sbyte == 1);
1862         if (bus->info->load_request) {
1863             req->hba_private = bus->info->load_request(f, req);
1864         }
1865         if (req->ops->load_request) {
1866             req->ops->load_request(f, req);
1867         }
1868 
1869         /* Just restart it later.  */
1870         scsi_req_enqueue_internal(req);
1871 
1872         /* At this point, the request will be kept alive by the reference
1873          * added by scsi_req_enqueue_internal, so we can release our reference.
1874          * The HBA of course will add its own reference in the load_request
1875          * callback if it needs to hold on the SCSIRequest.
1876          */
1877         scsi_req_unref(req);
1878     }
1879 
1880     return 0;
1881 }
1882 
1883 static const VMStateInfo vmstate_info_scsi_requests = {
1884     .name = "scsi-requests",
1885     .get  = get_scsi_requests,
1886     .put  = put_scsi_requests,
1887 };
1888 
1889 static bool scsi_sense_state_needed(void *opaque)
1890 {
1891     SCSIDevice *s = opaque;
1892 
1893     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1894 }
1895 
1896 static const VMStateDescription vmstate_scsi_sense_state = {
1897     .name = "SCSIDevice/sense",
1898     .version_id = 1,
1899     .minimum_version_id = 1,
1900     .needed = scsi_sense_state_needed,
1901     .fields = (const VMStateField[]) {
1902         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1903                                 SCSI_SENSE_BUF_SIZE_OLD,
1904                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1905         VMSTATE_END_OF_LIST()
1906     }
1907 };
1908 
1909 const VMStateDescription vmstate_scsi_device = {
1910     .name = "SCSIDevice",
1911     .version_id = 1,
1912     .minimum_version_id = 1,
1913     .fields = (const VMStateField[]) {
1914         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1915         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1916         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1917         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1918         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1919         VMSTATE_UINT32(sense_len, SCSIDevice),
1920         {
1921             .name         = "requests",
1922             .version_id   = 0,
1923             .field_exists = NULL,
1924             .size         = 0,   /* ouch */
1925             .info         = &vmstate_info_scsi_requests,
1926             .flags        = VMS_SINGLE,
1927             .offset       = 0,
1928         },
1929         VMSTATE_END_OF_LIST()
1930     },
1931     .subsections = (const VMStateDescription * const []) {
1932         &vmstate_scsi_sense_state,
1933         NULL
1934     }
1935 };
1936 
1937 static Property scsi_props[] = {
1938     DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
1939     DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
1940     DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
1941     DEFINE_PROP_END_OF_LIST(),
1942 };
1943 
1944 static void scsi_device_class_init(ObjectClass *klass, void *data)
1945 {
1946     DeviceClass *k = DEVICE_CLASS(klass);
1947     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1948     k->bus_type  = TYPE_SCSI_BUS;
1949     k->realize   = scsi_qdev_realize;
1950     k->unrealize = scsi_qdev_unrealize;
1951     device_class_set_props(k, scsi_props);
1952 }
1953 
1954 static void scsi_dev_instance_init(Object *obj)
1955 {
1956     DeviceState *dev = DEVICE(obj);
1957     SCSIDevice *s = SCSI_DEVICE(dev);
1958 
1959     device_add_bootindex_property(obj, &s->conf.bootindex,
1960                                   "bootindex", NULL,
1961                                   &s->qdev);
1962 }
1963 
1964 static const TypeInfo scsi_device_type_info = {
1965     .name = TYPE_SCSI_DEVICE,
1966     .parent = TYPE_DEVICE,
1967     .instance_size = sizeof(SCSIDevice),
1968     .abstract = true,
1969     .class_size = sizeof(SCSIDeviceClass),
1970     .class_init = scsi_device_class_init,
1971     .instance_init = scsi_dev_instance_init,
1972 };
1973 
1974 static void scsi_bus_class_init(ObjectClass *klass, void *data)
1975 {
1976     BusClass *k = BUS_CLASS(klass);
1977     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1978 
1979     k->get_dev_path = scsibus_get_dev_path;
1980     k->get_fw_dev_path = scsibus_get_fw_dev_path;
1981     k->check_address = scsi_bus_check_address;
1982     hc->unplug = qdev_simple_device_unplug_cb;
1983 }
1984 
1985 static const TypeInfo scsi_bus_info = {
1986     .name = TYPE_SCSI_BUS,
1987     .parent = TYPE_BUS,
1988     .instance_size = sizeof(SCSIBus),
1989     .class_init = scsi_bus_class_init,
1990     .interfaces = (InterfaceInfo[]) {
1991         { TYPE_HOTPLUG_HANDLER },
1992         { }
1993     }
1994 };
1995 
1996 static void scsi_register_types(void)
1997 {
1998     type_register_static(&scsi_bus_info);
1999     type_register_static(&scsi_device_type_info);
2000 }
2001 
2002 type_init(scsi_register_types)
2003