xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision d525f73f)
1 #include "qemu/osdep.h"
2 #include "qapi/error.h"
3 #include "qemu/error-report.h"
4 #include "qemu/module.h"
5 #include "qemu/option.h"
6 #include "qemu/hw-version.h"
7 #include "hw/qdev-properties.h"
8 #include "hw/scsi/scsi.h"
9 #include "migration/qemu-file-types.h"
10 #include "migration/vmstate.h"
11 #include "scsi/constants.h"
12 #include "sysemu/block-backend.h"
13 #include "sysemu/blockdev.h"
14 #include "sysemu/sysemu.h"
15 #include "sysemu/runstate.h"
16 #include "trace.h"
17 #include "sysemu/dma.h"
18 #include "qemu/cutils.h"
19 
20 static char *scsibus_get_dev_path(DeviceState *dev);
21 static char *scsibus_get_fw_dev_path(DeviceState *dev);
22 static void scsi_req_dequeue(SCSIRequest *req);
23 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len);
24 static void scsi_target_free_buf(SCSIRequest *req);
25 
26 static int next_scsi_bus;
27 
28 static SCSIDevice *do_scsi_device_find(SCSIBus *bus,
29                                        int channel, int id, int lun,
30                                        bool include_unrealized)
31 {
32     BusChild *kid;
33     SCSIDevice *retval = NULL;
34 
35     QTAILQ_FOREACH_RCU(kid, &bus->qbus.children, sibling) {
36         DeviceState *qdev = kid->child;
37         SCSIDevice *dev = SCSI_DEVICE(qdev);
38 
39         if (dev->channel == channel && dev->id == id) {
40             if (dev->lun == lun) {
41                 retval = dev;
42                 break;
43             }
44 
45             /*
46              * If we don't find exact match (channel/bus/lun),
47              * we will return the first device which matches channel/bus
48              */
49 
50             if (!retval) {
51                 retval = dev;
52             }
53         }
54     }
55 
56     /*
57      * This function might run on the IO thread and we might race against
58      * main thread hot-plugging the device.
59      * We assume that as soon as .realized is set to true we can let
60      * the user access the device.
61      */
62 
63     if (retval && !include_unrealized &&
64         !qatomic_load_acquire(&retval->qdev.realized)) {
65         retval = NULL;
66     }
67 
68     return retval;
69 }
70 
71 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
72 {
73     RCU_READ_LOCK_GUARD();
74     return do_scsi_device_find(bus, channel, id, lun, false);
75 }
76 
77 SCSIDevice *scsi_device_get(SCSIBus *bus, int channel, int id, int lun)
78 {
79     SCSIDevice *d;
80     RCU_READ_LOCK_GUARD();
81     d = do_scsi_device_find(bus, channel, id, lun, false);
82     if (d) {
83         object_ref(d);
84     }
85     return d;
86 }
87 
88 static void scsi_device_realize(SCSIDevice *s, Error **errp)
89 {
90     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
91     if (sc->realize) {
92         sc->realize(s, errp);
93     }
94 }
95 
96 static void scsi_device_unrealize(SCSIDevice *s)
97 {
98     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
99     if (sc->unrealize) {
100         sc->unrealize(s);
101     }
102 }
103 
104 int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
105                        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(ctx, scsi_dma_restart_bh, s);
197         qemu_bh_schedule(s->bh);
198     }
199 }
200 
201 static bool scsi_bus_is_address_free(SCSIBus *bus,
202 				     int channel, int target, int lun,
203 				     SCSIDevice **p_dev)
204 {
205     SCSIDevice *d;
206 
207     RCU_READ_LOCK_GUARD();
208     d = do_scsi_device_find(bus, channel, target, lun, true);
209     if (d && d->lun == lun) {
210         if (p_dev) {
211             *p_dev = d;
212         }
213         return false;
214     }
215     if (p_dev) {
216         *p_dev = NULL;
217     }
218     return true;
219 }
220 
221 static bool scsi_bus_check_address(BusState *qbus, DeviceState *qdev, Error **errp)
222 {
223     SCSIDevice *dev = SCSI_DEVICE(qdev);
224     SCSIBus *bus = SCSI_BUS(qbus);
225 
226     if (dev->channel > bus->info->max_channel) {
227         error_setg(errp, "bad scsi channel id: %d", dev->channel);
228         return false;
229     }
230     if (dev->id != -1 && dev->id > bus->info->max_target) {
231         error_setg(errp, "bad scsi device id: %d", dev->id);
232         return false;
233     }
234     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
235         error_setg(errp, "bad scsi device lun: %d", dev->lun);
236         return false;
237     }
238 
239     if (dev->id != -1 && dev->lun != -1) {
240         SCSIDevice *d;
241         if (!scsi_bus_is_address_free(bus, dev->channel, dev->id, dev->lun, &d)) {
242             error_setg(errp, "lun already used by '%s'", d->qdev.id);
243             return false;
244         }
245     }
246 
247     return true;
248 }
249 
250 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
251 {
252     SCSIDevice *dev = SCSI_DEVICE(qdev);
253     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
254     bool is_free;
255     Error *local_err = NULL;
256 
257     if (dev->id == -1) {
258         int id = -1;
259         if (dev->lun == -1) {
260             dev->lun = 0;
261         }
262         do {
263             is_free = scsi_bus_is_address_free(bus, dev->channel, ++id, dev->lun, NULL);
264         } while (!is_free && id < bus->info->max_target);
265         if (!is_free) {
266             error_setg(errp, "no free target");
267             return;
268         }
269         dev->id = id;
270     } else if (dev->lun == -1) {
271         int lun = -1;
272         do {
273             is_free = scsi_bus_is_address_free(bus, dev->channel, dev->id, ++lun, NULL);
274         } while (!is_free && lun < bus->info->max_lun);
275         if (!is_free) {
276             error_setg(errp, "no free lun");
277             return;
278         }
279         dev->lun = lun;
280     }
281 
282     QTAILQ_INIT(&dev->requests);
283     scsi_device_realize(dev, &local_err);
284     if (local_err) {
285         error_propagate(errp, local_err);
286         return;
287     }
288     dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
289             scsi_dma_restart_cb, dev);
290 }
291 
292 static void scsi_qdev_unrealize(DeviceState *qdev)
293 {
294     SCSIDevice *dev = SCSI_DEVICE(qdev);
295 
296     if (dev->vmsentry) {
297         qemu_del_vm_change_state_handler(dev->vmsentry);
298     }
299 
300     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
301 
302     scsi_device_unrealize(dev);
303 
304     blockdev_mark_auto_del(dev->conf.blk);
305 }
306 
307 /* handle legacy '-drive if=scsi,...' cmd line args */
308 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
309                                       int unit, bool removable, int bootindex,
310                                       bool share_rw,
311                                       BlockdevOnError rerror,
312                                       BlockdevOnError werror,
313                                       const char *serial, Error **errp)
314 {
315     const char *driver;
316     char *name;
317     DeviceState *dev;
318     DriveInfo *dinfo;
319 
320     if (blk_is_sg(blk)) {
321         driver = "scsi-generic";
322     } else {
323         dinfo = blk_legacy_dinfo(blk);
324         if (dinfo && dinfo->media_cd) {
325             driver = "scsi-cd";
326         } else {
327             driver = "scsi-hd";
328         }
329     }
330     dev = qdev_new(driver);
331     name = g_strdup_printf("legacy[%d]", unit);
332     object_property_add_child(OBJECT(bus), name, OBJECT(dev));
333     g_free(name);
334 
335     qdev_prop_set_uint32(dev, "scsi-id", unit);
336     if (bootindex >= 0) {
337         object_property_set_int(OBJECT(dev), "bootindex", bootindex,
338                                 &error_abort);
339     }
340     if (object_property_find(OBJECT(dev), "removable")) {
341         qdev_prop_set_bit(dev, "removable", removable);
342     }
343     if (serial && object_property_find(OBJECT(dev), "serial")) {
344         qdev_prop_set_string(dev, "serial", serial);
345     }
346     if (!qdev_prop_set_drive_err(dev, "drive", blk, errp)) {
347         object_unparent(OBJECT(dev));
348         return NULL;
349     }
350     if (!object_property_set_bool(OBJECT(dev), "share-rw", share_rw, errp)) {
351         object_unparent(OBJECT(dev));
352         return NULL;
353     }
354 
355     qdev_prop_set_enum(dev, "rerror", rerror);
356     qdev_prop_set_enum(dev, "werror", werror);
357 
358     if (!qdev_realize_and_unref(dev, &bus->qbus, errp)) {
359         object_unparent(OBJECT(dev));
360         return NULL;
361     }
362     return SCSI_DEVICE(dev);
363 }
364 
365 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
366 {
367     Location loc;
368     DriveInfo *dinfo;
369     int unit;
370 
371     loc_push_none(&loc);
372     for (unit = 0; unit <= bus->info->max_target; unit++) {
373         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
374         if (dinfo == NULL) {
375             continue;
376         }
377         qemu_opts_loc_restore(dinfo->opts);
378         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
379                                   unit, false, -1, false,
380                                   BLOCKDEV_ON_ERROR_AUTO,
381                                   BLOCKDEV_ON_ERROR_AUTO,
382                                   NULL, &error_fatal);
383     }
384     loc_pop(&loc);
385 }
386 
387 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
388 {
389     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
390     scsi_req_complete(req, CHECK_CONDITION);
391     return 0;
392 }
393 
394 static const struct SCSIReqOps reqops_invalid_field = {
395     .size         = sizeof(SCSIRequest),
396     .send_command = scsi_invalid_field
397 };
398 
399 /* SCSIReqOps implementation for invalid commands.  */
400 
401 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
402 {
403     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
404     scsi_req_complete(req, CHECK_CONDITION);
405     return 0;
406 }
407 
408 static const struct SCSIReqOps reqops_invalid_opcode = {
409     .size         = sizeof(SCSIRequest),
410     .send_command = scsi_invalid_command
411 };
412 
413 /* SCSIReqOps implementation for unit attention conditions.  */
414 
415 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
416 {
417     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
418         scsi_req_build_sense(req, req->dev->unit_attention);
419     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
420         scsi_req_build_sense(req, req->bus->unit_attention);
421     }
422     scsi_req_complete(req, CHECK_CONDITION);
423     return 0;
424 }
425 
426 static const struct SCSIReqOps reqops_unit_attention = {
427     .size         = sizeof(SCSIRequest),
428     .send_command = scsi_unit_attention
429 };
430 
431 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
432    an invalid LUN.  */
433 
434 typedef struct SCSITargetReq SCSITargetReq;
435 
436 struct SCSITargetReq {
437     SCSIRequest req;
438     int len;
439     uint8_t *buf;
440     int buf_len;
441 };
442 
443 static void store_lun(uint8_t *outbuf, int lun)
444 {
445     if (lun < 256) {
446         /* Simple logical unit addressing method*/
447         outbuf[0] = 0;
448         outbuf[1] = lun;
449     } else {
450         /* Flat space addressing method */
451         outbuf[0] = 0x40 | (lun >> 8);
452         outbuf[1] = (lun & 255);
453     }
454 }
455 
456 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
457 {
458     BusChild *kid;
459     int channel, id;
460     uint8_t tmp[8] = {0};
461     int len = 0;
462     GByteArray *buf;
463 
464     if (r->req.cmd.xfer < 16) {
465         return false;
466     }
467     if (r->req.cmd.buf[2] > 2) {
468         return false;
469     }
470 
471     /* reserve space for 63 LUNs*/
472     buf = g_byte_array_sized_new(512);
473 
474     channel = r->req.dev->channel;
475     id = r->req.dev->id;
476 
477     /* add size (will be updated later to correct value */
478     g_byte_array_append(buf, tmp, 8);
479     len += 8;
480 
481     /* add LUN0 */
482     g_byte_array_append(buf, tmp, 8);
483     len += 8;
484 
485     WITH_RCU_READ_LOCK_GUARD() {
486         QTAILQ_FOREACH_RCU(kid, &r->req.bus->qbus.children, sibling) {
487             DeviceState *qdev = kid->child;
488             SCSIDevice *dev = SCSI_DEVICE(qdev);
489 
490             if (dev->channel == channel && dev->id == id && dev->lun != 0) {
491                 store_lun(tmp, dev->lun);
492                 g_byte_array_append(buf, tmp, 8);
493                 len += 8;
494             }
495         }
496     }
497 
498     r->buf_len = len;
499     r->buf = g_byte_array_free(buf, FALSE);
500     r->len = MIN(len, r->req.cmd.xfer & ~7);
501 
502     /* store the LUN list length */
503     stl_be_p(&r->buf[0], len - 8);
504     return true;
505 }
506 
507 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
508 {
509     assert(r->req.dev->lun != r->req.lun);
510 
511     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
512 
513     if (r->req.cmd.buf[1] & 0x2) {
514         /* Command support data - optional, not implemented */
515         return false;
516     }
517 
518     if (r->req.cmd.buf[1] & 0x1) {
519         /* Vital product data */
520         uint8_t page_code = r->req.cmd.buf[2];
521         r->buf[r->len++] = page_code ; /* this page */
522         r->buf[r->len++] = 0x00;
523 
524         switch (page_code) {
525         case 0x00: /* Supported page codes, mandatory */
526         {
527             int pages;
528             pages = r->len++;
529             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
530             r->buf[pages] = r->len - pages - 1; /* number of pages */
531             break;
532         }
533         default:
534             return false;
535         }
536         /* done with EVPD */
537         assert(r->len < r->buf_len);
538         r->len = MIN(r->req.cmd.xfer, r->len);
539         return true;
540     }
541 
542     /* Standard INQUIRY data */
543     if (r->req.cmd.buf[2] != 0) {
544         return false;
545     }
546 
547     /* PAGE CODE == 0 */
548     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
549     memset(r->buf, 0, r->len);
550     if (r->req.lun != 0) {
551         r->buf[0] = TYPE_NO_LUN;
552     } else {
553         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
554         r->buf[2] = 5; /* Version */
555         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
556         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
557         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
558         memcpy(&r->buf[8], "QEMU    ", 8);
559         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
560         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
561     }
562     return true;
563 }
564 
565 static size_t scsi_sense_len(SCSIRequest *req)
566 {
567     if (req->dev->type == TYPE_SCANNER)
568         return SCSI_SENSE_LEN_SCANNER;
569     else
570         return SCSI_SENSE_LEN;
571 }
572 
573 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
574 {
575     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
576     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
577 
578     if (req->lun != 0 &&
579         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
580         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
581         scsi_req_complete(req, CHECK_CONDITION);
582         return 0;
583     }
584     switch (buf[0]) {
585     case REPORT_LUNS:
586         if (!scsi_target_emulate_report_luns(r)) {
587             goto illegal_request;
588         }
589         break;
590     case INQUIRY:
591         if (!scsi_target_emulate_inquiry(r)) {
592             goto illegal_request;
593         }
594         break;
595     case REQUEST_SENSE:
596         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
597         if (req->lun != 0) {
598             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
599 
600             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
601                                           sense, fixed_sense);
602         } else {
603             r->len = scsi_device_get_sense(r->req.dev, r->buf,
604                                            MIN(req->cmd.xfer, r->buf_len),
605                                            fixed_sense);
606         }
607         if (r->req.dev->sense_is_ua) {
608             scsi_device_unit_attention_reported(req->dev);
609             r->req.dev->sense_len = 0;
610             r->req.dev->sense_is_ua = false;
611         }
612         break;
613     case TEST_UNIT_READY:
614         break;
615     default:
616         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
617         scsi_req_complete(req, CHECK_CONDITION);
618         return 0;
619     illegal_request:
620         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
621         scsi_req_complete(req, CHECK_CONDITION);
622         return 0;
623     }
624 
625     if (!r->len) {
626         scsi_req_complete(req, GOOD);
627     }
628     return r->len;
629 }
630 
631 static void scsi_target_read_data(SCSIRequest *req)
632 {
633     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
634     uint32_t n;
635 
636     n = r->len;
637     if (n > 0) {
638         r->len = 0;
639         scsi_req_data(&r->req, n);
640     } else {
641         scsi_req_complete(&r->req, GOOD);
642     }
643 }
644 
645 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
646 {
647     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
648 
649     return r->buf;
650 }
651 
652 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
653 {
654     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
655 
656     r->buf = g_malloc(len);
657     r->buf_len = len;
658 
659     return r->buf;
660 }
661 
662 static void scsi_target_free_buf(SCSIRequest *req)
663 {
664     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
665 
666     g_free(r->buf);
667 }
668 
669 static const struct SCSIReqOps reqops_target_command = {
670     .size         = sizeof(SCSITargetReq),
671     .send_command = scsi_target_send_command,
672     .read_data    = scsi_target_read_data,
673     .get_buf      = scsi_target_get_buf,
674     .free_req     = scsi_target_free_buf,
675 };
676 
677 
678 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
679                             uint32_t tag, uint32_t lun, void *hba_private)
680 {
681     SCSIRequest *req;
682     SCSIBus *bus = scsi_bus_from_device(d);
683     BusState *qbus = BUS(bus);
684     const int memset_off = offsetof(SCSIRequest, sense)
685                            + sizeof(req->sense);
686 
687     req = g_malloc(reqops->size);
688     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
689     req->refcount = 1;
690     req->bus = bus;
691     req->dev = d;
692     req->tag = tag;
693     req->lun = lun;
694     req->hba_private = hba_private;
695     req->status = -1;
696     req->host_status = -1;
697     req->ops = reqops;
698     object_ref(OBJECT(d));
699     object_ref(OBJECT(qbus->parent));
700     notifier_list_init(&req->cancel_notifiers);
701     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
702     return req;
703 }
704 
705 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
706                           uint8_t *buf, size_t buf_len, void *hba_private)
707 {
708     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
709     const SCSIReqOps *ops;
710     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
711     SCSIRequest *req;
712     SCSICommand cmd = { .len = 0 };
713     int ret;
714 
715     if (buf_len == 0) {
716         trace_scsi_req_parse_bad(d->id, lun, tag, 0);
717         goto invalid_opcode;
718     }
719 
720     if ((d->unit_attention.key == UNIT_ATTENTION ||
721          bus->unit_attention.key == UNIT_ATTENTION) &&
722         (buf[0] != INQUIRY &&
723          buf[0] != REPORT_LUNS &&
724          buf[0] != GET_CONFIGURATION &&
725          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
726 
727          /*
728           * If we already have a pending unit attention condition,
729           * report this one before triggering another one.
730           */
731          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
732         ops = &reqops_unit_attention;
733     } else if (lun != d->lun ||
734                buf[0] == REPORT_LUNS ||
735                (buf[0] == REQUEST_SENSE && d->sense_len)) {
736         ops = &reqops_target_command;
737     } else {
738         ops = NULL;
739     }
740 
741     if (ops != NULL || !sc->parse_cdb) {
742         ret = scsi_req_parse_cdb(d, &cmd, buf, buf_len);
743     } else {
744         ret = sc->parse_cdb(d, &cmd, buf, buf_len, hba_private);
745     }
746 
747     if (ret != 0) {
748         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
749 invalid_opcode:
750         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
751     } else {
752         assert(cmd.len != 0);
753         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
754                               cmd.mode, cmd.xfer);
755         if (cmd.lba != -1) {
756             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
757                                       cmd.lba);
758         }
759 
760         if (cmd.xfer > INT32_MAX) {
761             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
762         } else if (ops) {
763             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
764         } else {
765             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
766         }
767     }
768 
769     req->cmd = cmd;
770     req->residual = req->cmd.xfer;
771 
772     switch (buf[0]) {
773     case INQUIRY:
774         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
775         break;
776     case TEST_UNIT_READY:
777         trace_scsi_test_unit_ready(d->id, lun, tag);
778         break;
779     case REPORT_LUNS:
780         trace_scsi_report_luns(d->id, lun, tag);
781         break;
782     case REQUEST_SENSE:
783         trace_scsi_request_sense(d->id, lun, tag);
784         break;
785     default:
786         break;
787     }
788 
789     return req;
790 }
791 
792 uint8_t *scsi_req_get_buf(SCSIRequest *req)
793 {
794     return req->ops->get_buf(req);
795 }
796 
797 static void scsi_clear_unit_attention(SCSIRequest *req)
798 {
799     SCSISense *ua;
800     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
801         req->bus->unit_attention.key != UNIT_ATTENTION) {
802         return;
803     }
804 
805     /*
806      * If an INQUIRY command enters the enabled command state,
807      * the device server shall [not] clear any unit attention condition;
808      * See also MMC-6, paragraphs 6.5 and 6.6.2.
809      */
810     if (req->cmd.buf[0] == INQUIRY ||
811         req->cmd.buf[0] == GET_CONFIGURATION ||
812         req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
813         return;
814     }
815 
816     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
817         ua = &req->dev->unit_attention;
818     } else {
819         ua = &req->bus->unit_attention;
820     }
821 
822     /*
823      * If a REPORT LUNS command enters the enabled command state, [...]
824      * the device server shall clear any pending unit attention condition
825      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
826      */
827     if (req->cmd.buf[0] == REPORT_LUNS &&
828         !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
829           ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
830         return;
831     }
832 
833     *ua = SENSE_CODE(NO_SENSE);
834 }
835 
836 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
837 {
838     int ret;
839 
840     assert(len >= 14);
841     if (!req->sense_len) {
842         return 0;
843     }
844 
845     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
846 
847     /*
848      * FIXME: clearing unit attention conditions upon autosense should be done
849      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
850      * (SAM-5, 5.14).
851      *
852      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
853      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
854      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
855      */
856     if (req->dev->sense_is_ua) {
857         scsi_device_unit_attention_reported(req->dev);
858         req->dev->sense_len = 0;
859         req->dev->sense_is_ua = false;
860     }
861     return ret;
862 }
863 
864 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
865 {
866     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
867 }
868 
869 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
870 {
871     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
872                                sense.key, sense.asc, sense.ascq);
873     req->sense_len = scsi_build_sense(req->sense, sense);
874 }
875 
876 static void scsi_req_enqueue_internal(SCSIRequest *req)
877 {
878     assert(!req->enqueued);
879     scsi_req_ref(req);
880     if (req->bus->info->get_sg_list) {
881         req->sg = req->bus->info->get_sg_list(req);
882     } else {
883         req->sg = NULL;
884     }
885     req->enqueued = true;
886     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
887 }
888 
889 int32_t scsi_req_enqueue(SCSIRequest *req)
890 {
891     int32_t rc;
892 
893     assert(!req->retry);
894     scsi_req_enqueue_internal(req);
895     scsi_req_ref(req);
896     rc = req->ops->send_command(req, req->cmd.buf);
897     scsi_req_unref(req);
898     return rc;
899 }
900 
901 static void scsi_req_dequeue(SCSIRequest *req)
902 {
903     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
904     req->retry = false;
905     if (req->enqueued) {
906         QTAILQ_REMOVE(&req->dev->requests, req, next);
907         req->enqueued = false;
908         scsi_req_unref(req);
909     }
910 }
911 
912 static int scsi_get_performance_length(int num_desc, int type, int data_type)
913 {
914     /* MMC-6, paragraph 6.7.  */
915     switch (type) {
916     case 0:
917         if ((data_type & 3) == 0) {
918             /* Each descriptor is as in Table 295 - Nominal performance.  */
919             return 16 * num_desc + 8;
920         } else {
921             /* Each descriptor is as in Table 296 - Exceptions.  */
922             return 6 * num_desc + 8;
923         }
924     case 1:
925     case 4:
926     case 5:
927         return 8 * num_desc + 8;
928     case 2:
929         return 2048 * num_desc + 8;
930     case 3:
931         return 16 * num_desc + 8;
932     default:
933         return 8;
934     }
935 }
936 
937 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
938 {
939     int byte_block = (buf[2] >> 2) & 0x1;
940     int type = (buf[2] >> 4) & 0x1;
941     int xfer_unit;
942 
943     if (byte_block) {
944         if (type) {
945             xfer_unit = dev->blocksize;
946         } else {
947             xfer_unit = 512;
948         }
949     } else {
950         xfer_unit = 1;
951     }
952 
953     return xfer_unit;
954 }
955 
956 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
957 {
958     int length = buf[2] & 0x3;
959     int xfer;
960     int unit = ata_passthrough_xfer_unit(dev, buf);
961 
962     switch (length) {
963     case 0:
964     case 3: /* USB-specific.  */
965     default:
966         xfer = 0;
967         break;
968     case 1:
969         xfer = buf[3];
970         break;
971     case 2:
972         xfer = buf[4];
973         break;
974     }
975 
976     return xfer * unit;
977 }
978 
979 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
980 {
981     int extend = buf[1] & 0x1;
982     int length = buf[2] & 0x3;
983     int xfer;
984     int unit = ata_passthrough_xfer_unit(dev, buf);
985 
986     switch (length) {
987     case 0:
988     case 3: /* USB-specific.  */
989     default:
990         xfer = 0;
991         break;
992     case 1:
993         xfer = buf[4];
994         xfer |= (extend ? buf[3] << 8 : 0);
995         break;
996     case 2:
997         xfer = buf[6];
998         xfer |= (extend ? buf[5] << 8 : 0);
999         break;
1000     }
1001 
1002     return xfer * unit;
1003 }
1004 
1005 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1006 {
1007     cmd->xfer = scsi_cdb_xfer(buf);
1008     switch (buf[0]) {
1009     case TEST_UNIT_READY:
1010     case REWIND:
1011     case START_STOP:
1012     case SET_CAPACITY:
1013     case WRITE_FILEMARKS:
1014     case WRITE_FILEMARKS_16:
1015     case SPACE:
1016     case RESERVE:
1017     case RELEASE:
1018     case ERASE:
1019     case ALLOW_MEDIUM_REMOVAL:
1020     case SEEK_10:
1021     case SYNCHRONIZE_CACHE:
1022     case SYNCHRONIZE_CACHE_16:
1023     case LOCATE_16:
1024     case LOCK_UNLOCK_CACHE:
1025     case SET_CD_SPEED:
1026     case SET_LIMITS:
1027     case WRITE_LONG_10:
1028     case UPDATE_BLOCK:
1029     case RESERVE_TRACK:
1030     case SET_READ_AHEAD:
1031     case PRE_FETCH:
1032     case PRE_FETCH_16:
1033     case ALLOW_OVERWRITE:
1034         cmd->xfer = 0;
1035         break;
1036     case VERIFY_10:
1037     case VERIFY_12:
1038     case VERIFY_16:
1039         if ((buf[1] & 2) == 0) {
1040             cmd->xfer = 0;
1041         } else if ((buf[1] & 4) != 0) {
1042             cmd->xfer = 1;
1043         }
1044         cmd->xfer *= dev->blocksize;
1045         break;
1046     case MODE_SENSE:
1047         break;
1048     case WRITE_SAME_10:
1049     case WRITE_SAME_16:
1050         cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
1051         break;
1052     case READ_CAPACITY_10:
1053         cmd->xfer = 8;
1054         break;
1055     case READ_BLOCK_LIMITS:
1056         cmd->xfer = 6;
1057         break;
1058     case SEND_VOLUME_TAG:
1059         /* GPCMD_SET_STREAMING from multimedia commands.  */
1060         if (dev->type == TYPE_ROM) {
1061             cmd->xfer = buf[10] | (buf[9] << 8);
1062         } else {
1063             cmd->xfer = buf[9] | (buf[8] << 8);
1064         }
1065         break;
1066     case WRITE_6:
1067         /* length 0 means 256 blocks */
1068         if (cmd->xfer == 0) {
1069             cmd->xfer = 256;
1070         }
1071         /* fall through */
1072     case WRITE_10:
1073     case WRITE_VERIFY_10:
1074     case WRITE_12:
1075     case WRITE_VERIFY_12:
1076     case WRITE_16:
1077     case WRITE_VERIFY_16:
1078         cmd->xfer *= dev->blocksize;
1079         break;
1080     case READ_6:
1081     case READ_REVERSE:
1082         /* length 0 means 256 blocks */
1083         if (cmd->xfer == 0) {
1084             cmd->xfer = 256;
1085         }
1086         /* fall through */
1087     case READ_10:
1088     case READ_12:
1089     case READ_16:
1090         cmd->xfer *= dev->blocksize;
1091         break;
1092     case FORMAT_UNIT:
1093         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1094          * for block devices are restricted to the header right now.  */
1095         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1096             cmd->xfer = 12;
1097         } else {
1098             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1099         }
1100         break;
1101     case INQUIRY:
1102     case RECEIVE_DIAGNOSTIC:
1103     case SEND_DIAGNOSTIC:
1104         cmd->xfer = buf[4] | (buf[3] << 8);
1105         break;
1106     case READ_CD:
1107     case READ_BUFFER:
1108     case WRITE_BUFFER:
1109     case SEND_CUE_SHEET:
1110         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1111         break;
1112     case PERSISTENT_RESERVE_OUT:
1113         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1114         break;
1115     case ERASE_12:
1116         if (dev->type == TYPE_ROM) {
1117             /* MMC command GET PERFORMANCE.  */
1118             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1119                                                     buf[10], buf[1] & 0x1f);
1120         }
1121         break;
1122     case MECHANISM_STATUS:
1123     case READ_DVD_STRUCTURE:
1124     case SEND_DVD_STRUCTURE:
1125     case MAINTENANCE_OUT:
1126     case MAINTENANCE_IN:
1127         if (dev->type == TYPE_ROM) {
1128             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1129             cmd->xfer = buf[9] | (buf[8] << 8);
1130         }
1131         break;
1132     case ATA_PASSTHROUGH_12:
1133         if (dev->type == TYPE_ROM) {
1134             /* BLANK command of MMC */
1135             cmd->xfer = 0;
1136         } else {
1137             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1138         }
1139         break;
1140     case ATA_PASSTHROUGH_16:
1141         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1142         break;
1143     }
1144     return 0;
1145 }
1146 
1147 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1148 {
1149     switch (buf[0]) {
1150     /* stream commands */
1151     case ERASE_12:
1152     case ERASE_16:
1153         cmd->xfer = 0;
1154         break;
1155     case READ_6:
1156     case READ_REVERSE:
1157     case RECOVER_BUFFERED_DATA:
1158     case WRITE_6:
1159         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1160         if (buf[1] & 0x01) { /* fixed */
1161             cmd->xfer *= dev->blocksize;
1162         }
1163         break;
1164     case READ_16:
1165     case READ_REVERSE_16:
1166     case VERIFY_16:
1167     case WRITE_16:
1168         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1169         if (buf[1] & 0x01) { /* fixed */
1170             cmd->xfer *= dev->blocksize;
1171         }
1172         break;
1173     case REWIND:
1174     case LOAD_UNLOAD:
1175         cmd->xfer = 0;
1176         break;
1177     case SPACE_16:
1178         cmd->xfer = buf[13] | (buf[12] << 8);
1179         break;
1180     case READ_POSITION:
1181         switch (buf[1] & 0x1f) /* operation code */ {
1182         case SHORT_FORM_BLOCK_ID:
1183         case SHORT_FORM_VENDOR_SPECIFIC:
1184             cmd->xfer = 20;
1185             break;
1186         case LONG_FORM:
1187             cmd->xfer = 32;
1188             break;
1189         case EXTENDED_FORM:
1190             cmd->xfer = buf[8] | (buf[7] << 8);
1191             break;
1192         default:
1193             return -1;
1194         }
1195 
1196         break;
1197     case FORMAT_UNIT:
1198         cmd->xfer = buf[4] | (buf[3] << 8);
1199         break;
1200     /* generic commands */
1201     default:
1202         return scsi_req_xfer(cmd, dev, buf);
1203     }
1204     return 0;
1205 }
1206 
1207 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1208 {
1209     switch (buf[0]) {
1210     /* medium changer commands */
1211     case EXCHANGE_MEDIUM:
1212     case INITIALIZE_ELEMENT_STATUS:
1213     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1214     case MOVE_MEDIUM:
1215     case POSITION_TO_ELEMENT:
1216         cmd->xfer = 0;
1217         break;
1218     case READ_ELEMENT_STATUS:
1219         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1220         break;
1221 
1222     /* generic commands */
1223     default:
1224         return scsi_req_xfer(cmd, dev, buf);
1225     }
1226     return 0;
1227 }
1228 
1229 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1230 {
1231     switch (buf[0]) {
1232     /* Scanner commands */
1233     case OBJECT_POSITION:
1234         cmd->xfer = 0;
1235         break;
1236     case SCAN:
1237         cmd->xfer = buf[4];
1238         break;
1239     case READ_10:
1240     case SEND:
1241     case GET_WINDOW:
1242     case SET_WINDOW:
1243         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1244         break;
1245     default:
1246         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1247         return scsi_req_xfer(cmd, dev, buf);
1248     }
1249 
1250     return 0;
1251 }
1252 
1253 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1254 {
1255     if (!cmd->xfer) {
1256         cmd->mode = SCSI_XFER_NONE;
1257         return;
1258     }
1259     switch (cmd->buf[0]) {
1260     case WRITE_6:
1261     case WRITE_10:
1262     case WRITE_VERIFY_10:
1263     case WRITE_12:
1264     case WRITE_VERIFY_12:
1265     case WRITE_16:
1266     case WRITE_VERIFY_16:
1267     case VERIFY_10:
1268     case VERIFY_12:
1269     case VERIFY_16:
1270     case COPY:
1271     case COPY_VERIFY:
1272     case COMPARE:
1273     case CHANGE_DEFINITION:
1274     case LOG_SELECT:
1275     case MODE_SELECT:
1276     case MODE_SELECT_10:
1277     case SEND_DIAGNOSTIC:
1278     case WRITE_BUFFER:
1279     case FORMAT_UNIT:
1280     case REASSIGN_BLOCKS:
1281     case SEARCH_EQUAL:
1282     case SEARCH_HIGH:
1283     case SEARCH_LOW:
1284     case UPDATE_BLOCK:
1285     case WRITE_LONG_10:
1286     case WRITE_SAME_10:
1287     case WRITE_SAME_16:
1288     case UNMAP:
1289     case SEARCH_HIGH_12:
1290     case SEARCH_EQUAL_12:
1291     case SEARCH_LOW_12:
1292     case MEDIUM_SCAN:
1293     case SEND_VOLUME_TAG:
1294     case SEND_CUE_SHEET:
1295     case SEND_DVD_STRUCTURE:
1296     case PERSISTENT_RESERVE_OUT:
1297     case MAINTENANCE_OUT:
1298     case SET_WINDOW:
1299     case SCAN:
1300         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1301          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1302          */
1303         cmd->mode = SCSI_XFER_TO_DEV;
1304         break;
1305     case ATA_PASSTHROUGH_12:
1306     case ATA_PASSTHROUGH_16:
1307         /* T_DIR */
1308         cmd->mode = (cmd->buf[2] & 0x8) ?
1309                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1310         break;
1311     default:
1312         cmd->mode = SCSI_XFER_FROM_DEV;
1313         break;
1314     }
1315 }
1316 
1317 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
1318                        size_t buf_len)
1319 {
1320     int rc;
1321     int len;
1322 
1323     cmd->lba = -1;
1324     len = scsi_cdb_length(buf);
1325     if (len < 0 || len > buf_len) {
1326         return -1;
1327     }
1328 
1329     cmd->len = len;
1330     switch (dev->type) {
1331     case TYPE_TAPE:
1332         rc = scsi_req_stream_xfer(cmd, dev, buf);
1333         break;
1334     case TYPE_MEDIUM_CHANGER:
1335         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1336         break;
1337     case TYPE_SCANNER:
1338         rc = scsi_req_scanner_length(cmd, dev, buf);
1339         break;
1340     default:
1341         rc = scsi_req_xfer(cmd, dev, buf);
1342         break;
1343     }
1344 
1345     if (rc != 0)
1346         return rc;
1347 
1348     memcpy(cmd->buf, buf, cmd->len);
1349     scsi_cmd_xfer_mode(cmd);
1350     cmd->lba = scsi_cmd_lba(cmd);
1351     return 0;
1352 }
1353 
1354 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1355 {
1356     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1357 
1358     scsi_device_set_ua(dev, sense);
1359     if (bus->info->change) {
1360         bus->info->change(bus, dev, sense);
1361     }
1362 }
1363 
1364 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1365 {
1366     assert(req->refcount > 0);
1367     req->refcount++;
1368     return req;
1369 }
1370 
1371 void scsi_req_unref(SCSIRequest *req)
1372 {
1373     assert(req->refcount > 0);
1374     if (--req->refcount == 0) {
1375         BusState *qbus = req->dev->qdev.parent_bus;
1376         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1377 
1378         if (bus->info->free_request && req->hba_private) {
1379             bus->info->free_request(bus, req->hba_private);
1380         }
1381         if (req->ops->free_req) {
1382             req->ops->free_req(req);
1383         }
1384         object_unref(OBJECT(req->dev));
1385         object_unref(OBJECT(qbus->parent));
1386         g_free(req);
1387     }
1388 }
1389 
1390 /* Tell the device that we finished processing this chunk of I/O.  It
1391    will start the next chunk or complete the command.  */
1392 void scsi_req_continue(SCSIRequest *req)
1393 {
1394     if (req->io_canceled) {
1395         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1396         return;
1397     }
1398     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1399     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1400         req->ops->write_data(req);
1401     } else {
1402         req->ops->read_data(req);
1403     }
1404 }
1405 
1406 /* Called by the devices when data is ready for the HBA.  The HBA should
1407    start a DMA operation to read or fill the device's data buffer.
1408    Once it completes, calling scsi_req_continue will restart I/O.  */
1409 void scsi_req_data(SCSIRequest *req, int len)
1410 {
1411     uint8_t *buf;
1412     if (req->io_canceled) {
1413         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1414         return;
1415     }
1416     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1417     assert(req->cmd.mode != SCSI_XFER_NONE);
1418     if (!req->sg) {
1419         req->residual -= len;
1420         req->bus->info->transfer_data(req, len);
1421         return;
1422     }
1423 
1424     /* If the device calls scsi_req_data and the HBA specified a
1425      * scatter/gather list, the transfer has to happen in a single
1426      * step.  */
1427     assert(!req->dma_started);
1428     req->dma_started = true;
1429 
1430     buf = scsi_req_get_buf(req);
1431     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1432         dma_buf_read(buf, len, &req->residual, req->sg,
1433                      MEMTXATTRS_UNSPECIFIED);
1434     } else {
1435         dma_buf_write(buf, len, &req->residual, req->sg,
1436                       MEMTXATTRS_UNSPECIFIED);
1437     }
1438     scsi_req_continue(req);
1439 }
1440 
1441 void scsi_req_print(SCSIRequest *req)
1442 {
1443     FILE *fp = stderr;
1444     int i;
1445 
1446     fprintf(fp, "[%s id=%d] %s",
1447             req->dev->qdev.parent_bus->name,
1448             req->dev->id,
1449             scsi_command_name(req->cmd.buf[0]));
1450     for (i = 1; i < req->cmd.len; i++) {
1451         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1452     }
1453     switch (req->cmd.mode) {
1454     case SCSI_XFER_NONE:
1455         fprintf(fp, " - none\n");
1456         break;
1457     case SCSI_XFER_FROM_DEV:
1458         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1459         break;
1460     case SCSI_XFER_TO_DEV:
1461         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1462         break;
1463     default:
1464         fprintf(fp, " - Oops\n");
1465         break;
1466     }
1467 }
1468 
1469 void scsi_req_complete_failed(SCSIRequest *req, int host_status)
1470 {
1471     SCSISense sense;
1472     int status;
1473 
1474     assert(req->status == -1 && req->host_status == -1);
1475     assert(req->ops != &reqops_unit_attention);
1476 
1477     if (!req->bus->info->fail) {
1478         status = scsi_sense_from_host_status(req->host_status, &sense);
1479         if (status == CHECK_CONDITION) {
1480             scsi_req_build_sense(req, sense);
1481         }
1482         scsi_req_complete(req, status);
1483         return;
1484     }
1485 
1486     req->host_status = host_status;
1487     scsi_req_ref(req);
1488     scsi_req_dequeue(req);
1489     req->bus->info->fail(req);
1490 
1491     /* Cancelled requests might end up being completed instead of cancelled */
1492     notifier_list_notify(&req->cancel_notifiers, req);
1493     scsi_req_unref(req);
1494 }
1495 
1496 void scsi_req_complete(SCSIRequest *req, int status)
1497 {
1498     assert(req->status == -1 && req->host_status == -1);
1499     req->status = status;
1500     req->host_status = SCSI_HOST_OK;
1501 
1502     assert(req->sense_len <= sizeof(req->sense));
1503     if (status == GOOD) {
1504         req->sense_len = 0;
1505     }
1506 
1507     if (req->sense_len) {
1508         memcpy(req->dev->sense, req->sense, req->sense_len);
1509         req->dev->sense_len = req->sense_len;
1510         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1511     } else {
1512         req->dev->sense_len = 0;
1513         req->dev->sense_is_ua = false;
1514     }
1515 
1516     /*
1517      * Unit attention state is now stored in the device's sense buffer
1518      * if the HBA didn't do autosense.  Clear the pending unit attention
1519      * flags.
1520      */
1521     scsi_clear_unit_attention(req);
1522 
1523     scsi_req_ref(req);
1524     scsi_req_dequeue(req);
1525     req->bus->info->complete(req, req->residual);
1526 
1527     /* Cancelled requests might end up being completed instead of cancelled */
1528     notifier_list_notify(&req->cancel_notifiers, req);
1529     scsi_req_unref(req);
1530 }
1531 
1532 /* Called by the devices when the request is canceled. */
1533 void scsi_req_cancel_complete(SCSIRequest *req)
1534 {
1535     assert(req->io_canceled);
1536     if (req->bus->info->cancel) {
1537         req->bus->info->cancel(req);
1538     }
1539     notifier_list_notify(&req->cancel_notifiers, req);
1540     scsi_req_unref(req);
1541 }
1542 
1543 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1544  * notifier list, the bus will be notified the requests cancellation is
1545  * completed.
1546  * */
1547 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1548 {
1549     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1550     if (notifier) {
1551         notifier_list_add(&req->cancel_notifiers, notifier);
1552     }
1553     if (req->io_canceled) {
1554         /* A blk_aio_cancel_async is pending; when it finishes,
1555          * scsi_req_cancel_complete will be called and will
1556          * call the notifier we just added.  Just wait for that.
1557          */
1558         assert(req->aiocb);
1559         return;
1560     }
1561     /* Dropped in scsi_req_cancel_complete.  */
1562     scsi_req_ref(req);
1563     scsi_req_dequeue(req);
1564     req->io_canceled = true;
1565     if (req->aiocb) {
1566         blk_aio_cancel_async(req->aiocb);
1567     } else {
1568         scsi_req_cancel_complete(req);
1569     }
1570 }
1571 
1572 void scsi_req_cancel(SCSIRequest *req)
1573 {
1574     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1575     if (!req->enqueued) {
1576         return;
1577     }
1578     assert(!req->io_canceled);
1579     /* Dropped in scsi_req_cancel_complete.  */
1580     scsi_req_ref(req);
1581     scsi_req_dequeue(req);
1582     req->io_canceled = true;
1583     if (req->aiocb) {
1584         blk_aio_cancel(req->aiocb);
1585     } else {
1586         scsi_req_cancel_complete(req);
1587     }
1588 }
1589 
1590 static int scsi_ua_precedence(SCSISense sense)
1591 {
1592     if (sense.key != UNIT_ATTENTION) {
1593         return INT_MAX;
1594     }
1595     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1596         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1597         return 1;
1598     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1599         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1600         return 2;
1601     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1602         /* These two go with "all others". */
1603         ;
1604     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1605         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1606          * POWER ON OCCURRED = 1
1607          * SCSI BUS RESET OCCURRED = 2
1608          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1609          * I_T NEXUS LOSS OCCURRED = 7
1610          */
1611         return sense.ascq;
1612     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1613         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1614         return 8;
1615     }
1616     return (sense.asc << 8) | sense.ascq;
1617 }
1618 
1619 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1620 {
1621     int prec1, prec2;
1622     if (sense.key != UNIT_ATTENTION) {
1623         return;
1624     }
1625     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1626                              sense.asc, sense.ascq);
1627 
1628     /*
1629      * Override a pre-existing unit attention condition, except for a more
1630      * important reset condition.
1631     */
1632     prec1 = scsi_ua_precedence(sdev->unit_attention);
1633     prec2 = scsi_ua_precedence(sense);
1634     if (prec2 < prec1) {
1635         sdev->unit_attention = sense;
1636     }
1637 }
1638 
1639 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1640 {
1641     SCSIRequest *req;
1642 
1643     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1644     while (!QTAILQ_EMPTY(&sdev->requests)) {
1645         req = QTAILQ_FIRST(&sdev->requests);
1646         scsi_req_cancel_async(req, NULL);
1647     }
1648     blk_drain(sdev->conf.blk);
1649     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1650     scsi_device_set_ua(sdev, sense);
1651 }
1652 
1653 static char *scsibus_get_dev_path(DeviceState *dev)
1654 {
1655     SCSIDevice *d = SCSI_DEVICE(dev);
1656     DeviceState *hba = dev->parent_bus->parent;
1657     char *id;
1658     char *path;
1659 
1660     id = qdev_get_dev_path(hba);
1661     if (id) {
1662         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1663     } else {
1664         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1665     }
1666     g_free(id);
1667     return path;
1668 }
1669 
1670 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1671 {
1672     SCSIDevice *d = SCSI_DEVICE(dev);
1673     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1674                            qdev_fw_name(dev), d->id, d->lun);
1675 }
1676 
1677 /* SCSI request list.  For simplicity, pv points to the whole device */
1678 
1679 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1680                              const VMStateField *field, JSONWriter *vmdesc)
1681 {
1682     SCSIDevice *s = pv;
1683     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1684     SCSIRequest *req;
1685 
1686     QTAILQ_FOREACH(req, &s->requests, next) {
1687         assert(!req->io_canceled);
1688         assert(req->status == -1 && req->host_status == -1);
1689         assert(req->enqueued);
1690 
1691         qemu_put_sbyte(f, req->retry ? 1 : 2);
1692         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1693         qemu_put_be32s(f, &req->tag);
1694         qemu_put_be32s(f, &req->lun);
1695         if (bus->info->save_request) {
1696             bus->info->save_request(f, req);
1697         }
1698         if (req->ops->save_request) {
1699             req->ops->save_request(f, req);
1700         }
1701     }
1702     qemu_put_sbyte(f, 0);
1703 
1704     return 0;
1705 }
1706 
1707 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1708                              const VMStateField *field)
1709 {
1710     SCSIDevice *s = pv;
1711     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1712     int8_t sbyte;
1713 
1714     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1715         uint8_t buf[SCSI_CMD_BUF_SIZE];
1716         uint32_t tag;
1717         uint32_t lun;
1718         SCSIRequest *req;
1719 
1720         qemu_get_buffer(f, buf, sizeof(buf));
1721         qemu_get_be32s(f, &tag);
1722         qemu_get_be32s(f, &lun);
1723         /*
1724          * A too-short CDB would have been rejected by scsi_req_new, so just use
1725          * SCSI_CMD_BUF_SIZE as the CDB length.
1726          */
1727         req = scsi_req_new(s, tag, lun, buf, sizeof(buf), NULL);
1728         req->retry = (sbyte == 1);
1729         if (bus->info->load_request) {
1730             req->hba_private = bus->info->load_request(f, req);
1731         }
1732         if (req->ops->load_request) {
1733             req->ops->load_request(f, req);
1734         }
1735 
1736         /* Just restart it later.  */
1737         scsi_req_enqueue_internal(req);
1738 
1739         /* At this point, the request will be kept alive by the reference
1740          * added by scsi_req_enqueue_internal, so we can release our reference.
1741          * The HBA of course will add its own reference in the load_request
1742          * callback if it needs to hold on the SCSIRequest.
1743          */
1744         scsi_req_unref(req);
1745     }
1746 
1747     return 0;
1748 }
1749 
1750 static const VMStateInfo vmstate_info_scsi_requests = {
1751     .name = "scsi-requests",
1752     .get  = get_scsi_requests,
1753     .put  = put_scsi_requests,
1754 };
1755 
1756 static bool scsi_sense_state_needed(void *opaque)
1757 {
1758     SCSIDevice *s = opaque;
1759 
1760     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1761 }
1762 
1763 static const VMStateDescription vmstate_scsi_sense_state = {
1764     .name = "SCSIDevice/sense",
1765     .version_id = 1,
1766     .minimum_version_id = 1,
1767     .needed = scsi_sense_state_needed,
1768     .fields = (VMStateField[]) {
1769         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1770                                 SCSI_SENSE_BUF_SIZE_OLD,
1771                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1772         VMSTATE_END_OF_LIST()
1773     }
1774 };
1775 
1776 const VMStateDescription vmstate_scsi_device = {
1777     .name = "SCSIDevice",
1778     .version_id = 1,
1779     .minimum_version_id = 1,
1780     .fields = (VMStateField[]) {
1781         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1782         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1783         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1784         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1785         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1786         VMSTATE_UINT32(sense_len, SCSIDevice),
1787         {
1788             .name         = "requests",
1789             .version_id   = 0,
1790             .field_exists = NULL,
1791             .size         = 0,   /* ouch */
1792             .info         = &vmstate_info_scsi_requests,
1793             .flags        = VMS_SINGLE,
1794             .offset       = 0,
1795         },
1796         VMSTATE_END_OF_LIST()
1797     },
1798     .subsections = (const VMStateDescription*[]) {
1799         &vmstate_scsi_sense_state,
1800         NULL
1801     }
1802 };
1803 
1804 static Property scsi_props[] = {
1805     DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
1806     DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
1807     DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
1808     DEFINE_PROP_END_OF_LIST(),
1809 };
1810 
1811 static void scsi_device_class_init(ObjectClass *klass, void *data)
1812 {
1813     DeviceClass *k = DEVICE_CLASS(klass);
1814     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1815     k->bus_type  = TYPE_SCSI_BUS;
1816     k->realize   = scsi_qdev_realize;
1817     k->unrealize = scsi_qdev_unrealize;
1818     device_class_set_props(k, scsi_props);
1819 }
1820 
1821 static void scsi_dev_instance_init(Object *obj)
1822 {
1823     DeviceState *dev = DEVICE(obj);
1824     SCSIDevice *s = SCSI_DEVICE(dev);
1825 
1826     device_add_bootindex_property(obj, &s->conf.bootindex,
1827                                   "bootindex", NULL,
1828                                   &s->qdev);
1829 }
1830 
1831 static const TypeInfo scsi_device_type_info = {
1832     .name = TYPE_SCSI_DEVICE,
1833     .parent = TYPE_DEVICE,
1834     .instance_size = sizeof(SCSIDevice),
1835     .abstract = true,
1836     .class_size = sizeof(SCSIDeviceClass),
1837     .class_init = scsi_device_class_init,
1838     .instance_init = scsi_dev_instance_init,
1839 };
1840 
1841 static void scsi_bus_class_init(ObjectClass *klass, void *data)
1842 {
1843     BusClass *k = BUS_CLASS(klass);
1844     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1845 
1846     k->get_dev_path = scsibus_get_dev_path;
1847     k->get_fw_dev_path = scsibus_get_fw_dev_path;
1848     k->check_address = scsi_bus_check_address;
1849     hc->unplug = qdev_simple_device_unplug_cb;
1850 }
1851 
1852 static const TypeInfo scsi_bus_info = {
1853     .name = TYPE_SCSI_BUS,
1854     .parent = TYPE_BUS,
1855     .instance_size = sizeof(SCSIBus),
1856     .class_init = scsi_bus_class_init,
1857     .interfaces = (InterfaceInfo[]) {
1858         { TYPE_HOTPLUG_HANDLER },
1859         { }
1860     }
1861 };
1862 
1863 static void scsi_register_types(void)
1864 {
1865     type_register_static(&scsi_bus_info);
1866     type_register_static(&scsi_device_type_info);
1867 }
1868 
1869 type_init(scsi_register_types)
1870