xref: /openbmc/qemu/hw/scsi/scsi-bus.c (revision 69430111)
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 "hw/qdev-properties.h"
7 #include "hw/scsi/scsi.h"
8 #include "migration/qemu-file-types.h"
9 #include "migration/vmstate.h"
10 #include "scsi/constants.h"
11 #include "sysemu/block-backend.h"
12 #include "sysemu/blockdev.h"
13 #include "sysemu/sysemu.h"
14 #include "sysemu/runstate.h"
15 #include "trace.h"
16 #include "sysemu/dma.h"
17 #include "qemu/cutils.h"
18 
19 static char *scsibus_get_dev_path(DeviceState *dev);
20 static char *scsibus_get_fw_dev_path(DeviceState *dev);
21 static void scsi_req_dequeue(SCSIRequest *req);
22 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len);
23 static void scsi_target_free_buf(SCSIRequest *req);
24 
25 static int next_scsi_bus;
26 
27 static SCSIDevice *do_scsi_device_find(SCSIBus *bus,
28                                        int channel, int id, int lun,
29                                        bool include_unrealized)
30 {
31     BusChild *kid;
32     SCSIDevice *retval = NULL;
33 
34     QTAILQ_FOREACH_RCU(kid, &bus->qbus.children, sibling) {
35         DeviceState *qdev = kid->child;
36         SCSIDevice *dev = SCSI_DEVICE(qdev);
37 
38         if (dev->channel == channel && dev->id == id) {
39             if (dev->lun == lun) {
40                 retval = dev;
41                 break;
42             }
43 
44             /*
45              * If we don't find exact match (channel/bus/lun),
46              * we will return the first device which matches channel/bus
47              */
48 
49             if (!retval) {
50                 retval = dev;
51             }
52         }
53     }
54 
55     /*
56      * This function might run on the IO thread and we might race against
57      * main thread hot-plugging the device.
58      * We assume that as soon as .realized is set to true we can let
59      * the user access the device.
60      */
61 
62     if (retval && !include_unrealized &&
63         !qatomic_load_acquire(&retval->qdev.realized)) {
64         retval = NULL;
65     }
66 
67     return retval;
68 }
69 
70 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
71 {
72     RCU_READ_LOCK_GUARD();
73     return do_scsi_device_find(bus, channel, id, lun, false);
74 }
75 
76 SCSIDevice *scsi_device_get(SCSIBus *bus, int channel, int id, int lun)
77 {
78     SCSIDevice *d;
79     RCU_READ_LOCK_GUARD();
80     d = do_scsi_device_find(bus, channel, id, lun, false);
81     if (d) {
82         object_ref(d);
83     }
84     return d;
85 }
86 
87 static void scsi_device_realize(SCSIDevice *s, Error **errp)
88 {
89     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
90     if (sc->realize) {
91         sc->realize(s, errp);
92     }
93 }
94 
95 static void scsi_device_unrealize(SCSIDevice *s)
96 {
97     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
98     if (sc->unrealize) {
99         sc->unrealize(s);
100     }
101 }
102 
103 int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
104                        void *hba_private)
105 {
106     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
107     int rc;
108 
109     assert(cmd->len == 0);
110     rc = scsi_req_parse_cdb(dev, cmd, buf);
111     if (bus->info->parse_cdb) {
112         rc = bus->info->parse_cdb(dev, cmd, buf, hba_private);
113     }
114     return rc;
115 }
116 
117 static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
118                                           uint8_t *buf, void *hba_private)
119 {
120     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
121     if (sc->alloc_req) {
122         return sc->alloc_req(s, tag, lun, buf, hba_private);
123     }
124 
125     return NULL;
126 }
127 
128 void scsi_device_unit_attention_reported(SCSIDevice *s)
129 {
130     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
131     if (sc->unit_attention_reported) {
132         sc->unit_attention_reported(s);
133     }
134 }
135 
136 /* Create a scsi bus, and attach devices to it.  */
137 void scsi_bus_new(SCSIBus *bus, size_t bus_size, DeviceState *host,
138                   const SCSIBusInfo *info, const char *bus_name)
139 {
140     qbus_create_inplace(bus, bus_size, TYPE_SCSI_BUS, host, bus_name);
141     bus->busnr = next_scsi_bus++;
142     bus->info = info;
143     qbus_set_bus_hotplug_handler(BUS(bus));
144 }
145 
146 static void scsi_dma_restart_bh(void *opaque)
147 {
148     SCSIDevice *s = opaque;
149     SCSIRequest *req, *next;
150 
151     qemu_bh_delete(s->bh);
152     s->bh = NULL;
153 
154     aio_context_acquire(blk_get_aio_context(s->conf.blk));
155     QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
156         scsi_req_ref(req);
157         if (req->retry) {
158             req->retry = false;
159             switch (req->cmd.mode) {
160             case SCSI_XFER_FROM_DEV:
161             case SCSI_XFER_TO_DEV:
162                 scsi_req_continue(req);
163                 break;
164             case SCSI_XFER_NONE:
165                 scsi_req_dequeue(req);
166                 scsi_req_enqueue(req);
167                 break;
168             }
169         }
170         scsi_req_unref(req);
171     }
172     aio_context_release(blk_get_aio_context(s->conf.blk));
173 }
174 
175 void scsi_req_retry(SCSIRequest *req)
176 {
177     /* No need to save a reference, because scsi_dma_restart_bh just
178      * looks at the request list.  */
179     req->retry = true;
180 }
181 
182 static void scsi_dma_restart_cb(void *opaque, int running, RunState state)
183 {
184     SCSIDevice *s = opaque;
185 
186     if (!running) {
187         return;
188     }
189     if (!s->bh) {
190         AioContext *ctx = blk_get_aio_context(s->conf.blk);
191         s->bh = aio_bh_new(ctx, scsi_dma_restart_bh, s);
192         qemu_bh_schedule(s->bh);
193     }
194 }
195 
196 static bool scsi_bus_is_address_free(SCSIBus *bus,
197 				     int channel, int target, int lun,
198 				     SCSIDevice **p_dev)
199 {
200     SCSIDevice *d;
201 
202     RCU_READ_LOCK_GUARD();
203     d = do_scsi_device_find(bus, channel, target, lun, true);
204     if (d && d->lun == lun) {
205         if (p_dev) {
206             *p_dev = d;
207         }
208         return false;
209     }
210     if (p_dev) {
211         *p_dev = NULL;
212     }
213     return true;
214 }
215 
216 static bool scsi_bus_check_address(BusState *qbus, DeviceState *qdev, Error **errp)
217 {
218     SCSIDevice *dev = SCSI_DEVICE(qdev);
219     SCSIBus *bus = SCSI_BUS(qbus);
220 
221     if (dev->channel > bus->info->max_channel) {
222         error_setg(errp, "bad scsi channel id: %d", dev->channel);
223         return false;
224     }
225     if (dev->id != -1 && dev->id > bus->info->max_target) {
226         error_setg(errp, "bad scsi device id: %d", dev->id);
227         return false;
228     }
229     if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
230         error_setg(errp, "bad scsi device lun: %d", dev->lun);
231         return false;
232     }
233 
234     if (dev->id != -1 && dev->lun != -1) {
235         SCSIDevice *d;
236         if (!scsi_bus_is_address_free(bus, dev->channel, dev->id, dev->lun, &d)) {
237             error_setg(errp, "lun already used by '%s'", d->qdev.id);
238             return false;
239         }
240     }
241 
242     return true;
243 }
244 
245 static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
246 {
247     SCSIDevice *dev = SCSI_DEVICE(qdev);
248     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
249     bool is_free;
250     Error *local_err = NULL;
251 
252     if (dev->id == -1) {
253         int id = -1;
254         if (dev->lun == -1) {
255             dev->lun = 0;
256         }
257         do {
258             is_free = scsi_bus_is_address_free(bus, dev->channel, ++id, dev->lun, NULL);
259         } while (!is_free && id < bus->info->max_target);
260         if (!is_free) {
261             error_setg(errp, "no free target");
262             return;
263         }
264         dev->id = id;
265     } else if (dev->lun == -1) {
266         int lun = -1;
267         do {
268             is_free = scsi_bus_is_address_free(bus, dev->channel, dev->id, ++lun, NULL);
269         } while (!is_free && lun < bus->info->max_lun);
270         if (!is_free) {
271             error_setg(errp, "no free lun");
272             return;
273         }
274         dev->lun = lun;
275     }
276 
277     QTAILQ_INIT(&dev->requests);
278     scsi_device_realize(dev, &local_err);
279     if (local_err) {
280         error_propagate(errp, local_err);
281         return;
282     }
283     dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
284             scsi_dma_restart_cb, dev);
285 }
286 
287 static void scsi_qdev_unrealize(DeviceState *qdev)
288 {
289     SCSIDevice *dev = SCSI_DEVICE(qdev);
290 
291     if (dev->vmsentry) {
292         qemu_del_vm_change_state_handler(dev->vmsentry);
293     }
294 
295     scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
296 
297     scsi_device_unrealize(dev);
298 
299     blockdev_mark_auto_del(dev->conf.blk);
300 }
301 
302 /* handle legacy '-drive if=scsi,...' cmd line args */
303 SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
304                                       int unit, bool removable, int bootindex,
305                                       bool share_rw,
306                                       BlockdevOnError rerror,
307                                       BlockdevOnError werror,
308                                       const char *serial, Error **errp)
309 {
310     const char *driver;
311     char *name;
312     DeviceState *dev;
313     DriveInfo *dinfo;
314 
315     if (blk_is_sg(blk)) {
316         driver = "scsi-generic";
317     } else {
318         dinfo = blk_legacy_dinfo(blk);
319         if (dinfo && dinfo->media_cd) {
320             driver = "scsi-cd";
321         } else {
322             driver = "scsi-hd";
323         }
324     }
325     dev = qdev_new(driver);
326     name = g_strdup_printf("legacy[%d]", unit);
327     object_property_add_child(OBJECT(bus), name, OBJECT(dev));
328     g_free(name);
329 
330     qdev_prop_set_uint32(dev, "scsi-id", unit);
331     if (bootindex >= 0) {
332         object_property_set_int(OBJECT(dev), "bootindex", bootindex,
333                                 &error_abort);
334     }
335     if (object_property_find(OBJECT(dev), "removable")) {
336         qdev_prop_set_bit(dev, "removable", removable);
337     }
338     if (serial && object_property_find(OBJECT(dev), "serial")) {
339         qdev_prop_set_string(dev, "serial", serial);
340     }
341     if (!qdev_prop_set_drive_err(dev, "drive", blk, errp)) {
342         object_unparent(OBJECT(dev));
343         return NULL;
344     }
345     if (!object_property_set_bool(OBJECT(dev), "share-rw", share_rw, errp)) {
346         object_unparent(OBJECT(dev));
347         return NULL;
348     }
349 
350     qdev_prop_set_enum(dev, "rerror", rerror);
351     qdev_prop_set_enum(dev, "werror", werror);
352 
353     if (!qdev_realize_and_unref(dev, &bus->qbus, errp)) {
354         object_unparent(OBJECT(dev));
355         return NULL;
356     }
357     return SCSI_DEVICE(dev);
358 }
359 
360 void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
361 {
362     Location loc;
363     DriveInfo *dinfo;
364     int unit;
365 
366     loc_push_none(&loc);
367     for (unit = 0; unit <= bus->info->max_target; unit++) {
368         dinfo = drive_get(IF_SCSI, bus->busnr, unit);
369         if (dinfo == NULL) {
370             continue;
371         }
372         qemu_opts_loc_restore(dinfo->opts);
373         scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
374                                   unit, false, -1, false,
375                                   BLOCKDEV_ON_ERROR_AUTO,
376                                   BLOCKDEV_ON_ERROR_AUTO,
377                                   NULL, &error_fatal);
378     }
379     loc_pop(&loc);
380 }
381 
382 static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
383 {
384     scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
385     scsi_req_complete(req, CHECK_CONDITION);
386     return 0;
387 }
388 
389 static const struct SCSIReqOps reqops_invalid_field = {
390     .size         = sizeof(SCSIRequest),
391     .send_command = scsi_invalid_field
392 };
393 
394 /* SCSIReqOps implementation for invalid commands.  */
395 
396 static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
397 {
398     scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
399     scsi_req_complete(req, CHECK_CONDITION);
400     return 0;
401 }
402 
403 static const struct SCSIReqOps reqops_invalid_opcode = {
404     .size         = sizeof(SCSIRequest),
405     .send_command = scsi_invalid_command
406 };
407 
408 /* SCSIReqOps implementation for unit attention conditions.  */
409 
410 static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
411 {
412     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
413         scsi_req_build_sense(req, req->dev->unit_attention);
414     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
415         scsi_req_build_sense(req, req->bus->unit_attention);
416     }
417     scsi_req_complete(req, CHECK_CONDITION);
418     return 0;
419 }
420 
421 static const struct SCSIReqOps reqops_unit_attention = {
422     .size         = sizeof(SCSIRequest),
423     .send_command = scsi_unit_attention
424 };
425 
426 /* SCSIReqOps implementation for REPORT LUNS and for commands sent to
427    an invalid LUN.  */
428 
429 typedef struct SCSITargetReq SCSITargetReq;
430 
431 struct SCSITargetReq {
432     SCSIRequest req;
433     int len;
434     uint8_t *buf;
435     int buf_len;
436 };
437 
438 static void store_lun(uint8_t *outbuf, int lun)
439 {
440     if (lun < 256) {
441         /* Simple logical unit addressing method*/
442         outbuf[0] = 0;
443         outbuf[1] = lun;
444     } else {
445         /* Flat space addressing method */
446         outbuf[0] = 0x40 | (lun >> 8);
447         outbuf[1] = (lun & 255);
448     }
449 }
450 
451 static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
452 {
453     BusChild *kid;
454     int channel, id;
455     uint8_t tmp[8] = {0};
456     int len = 0;
457     GByteArray *buf;
458 
459     if (r->req.cmd.xfer < 16) {
460         return false;
461     }
462     if (r->req.cmd.buf[2] > 2) {
463         return false;
464     }
465 
466     /* reserve space for 63 LUNs*/
467     buf = g_byte_array_sized_new(512);
468 
469     channel = r->req.dev->channel;
470     id = r->req.dev->id;
471 
472     /* add size (will be updated later to correct value */
473     g_byte_array_append(buf, tmp, 8);
474     len += 8;
475 
476     /* add LUN0 */
477     g_byte_array_append(buf, tmp, 8);
478     len += 8;
479 
480     WITH_RCU_READ_LOCK_GUARD() {
481         QTAILQ_FOREACH_RCU(kid, &r->req.bus->qbus.children, sibling) {
482             DeviceState *qdev = kid->child;
483             SCSIDevice *dev = SCSI_DEVICE(qdev);
484 
485             if (dev->channel == channel && dev->id == id && dev->lun != 0) {
486                 store_lun(tmp, dev->lun);
487                 g_byte_array_append(buf, tmp, 8);
488                 len += 8;
489             }
490         }
491     }
492 
493     r->buf_len = len;
494     r->buf = g_byte_array_free(buf, FALSE);
495     r->len = MIN(len, r->req.cmd.xfer & ~7);
496 
497     /* store the LUN list length */
498     stl_be_p(&r->buf[0], len - 8);
499     return true;
500 }
501 
502 static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
503 {
504     assert(r->req.dev->lun != r->req.lun);
505 
506     scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
507 
508     if (r->req.cmd.buf[1] & 0x2) {
509         /* Command support data - optional, not implemented */
510         return false;
511     }
512 
513     if (r->req.cmd.buf[1] & 0x1) {
514         /* Vital product data */
515         uint8_t page_code = r->req.cmd.buf[2];
516         r->buf[r->len++] = page_code ; /* this page */
517         r->buf[r->len++] = 0x00;
518 
519         switch (page_code) {
520         case 0x00: /* Supported page codes, mandatory */
521         {
522             int pages;
523             pages = r->len++;
524             r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
525             r->buf[pages] = r->len - pages - 1; /* number of pages */
526             break;
527         }
528         default:
529             return false;
530         }
531         /* done with EVPD */
532         assert(r->len < r->buf_len);
533         r->len = MIN(r->req.cmd.xfer, r->len);
534         return true;
535     }
536 
537     /* Standard INQUIRY data */
538     if (r->req.cmd.buf[2] != 0) {
539         return false;
540     }
541 
542     /* PAGE CODE == 0 */
543     r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
544     memset(r->buf, 0, r->len);
545     if (r->req.lun != 0) {
546         r->buf[0] = TYPE_NO_LUN;
547     } else {
548         r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
549         r->buf[2] = 5; /* Version */
550         r->buf[3] = 2 | 0x10; /* HiSup, response data format */
551         r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
552         r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
553         memcpy(&r->buf[8], "QEMU    ", 8);
554         memcpy(&r->buf[16], "QEMU TARGET     ", 16);
555         pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
556     }
557     return true;
558 }
559 
560 static size_t scsi_sense_len(SCSIRequest *req)
561 {
562     if (req->dev->type == TYPE_SCANNER)
563         return SCSI_SENSE_LEN_SCANNER;
564     else
565         return SCSI_SENSE_LEN;
566 }
567 
568 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
569 {
570     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
571     int fixed_sense = (req->cmd.buf[1] & 1) == 0;
572 
573     if (req->lun != 0 &&
574         buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
575         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
576         scsi_req_complete(req, CHECK_CONDITION);
577         return 0;
578     }
579     switch (buf[0]) {
580     case REPORT_LUNS:
581         if (!scsi_target_emulate_report_luns(r)) {
582             goto illegal_request;
583         }
584         break;
585     case INQUIRY:
586         if (!scsi_target_emulate_inquiry(r)) {
587             goto illegal_request;
588         }
589         break;
590     case REQUEST_SENSE:
591         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
592         if (req->lun != 0) {
593             const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
594 
595             r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
596                                           sense, fixed_sense);
597         } else {
598             r->len = scsi_device_get_sense(r->req.dev, r->buf,
599                                            MIN(req->cmd.xfer, r->buf_len),
600                                            fixed_sense);
601         }
602         if (r->req.dev->sense_is_ua) {
603             scsi_device_unit_attention_reported(req->dev);
604             r->req.dev->sense_len = 0;
605             r->req.dev->sense_is_ua = false;
606         }
607         break;
608     case TEST_UNIT_READY:
609         break;
610     default:
611         scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
612         scsi_req_complete(req, CHECK_CONDITION);
613         return 0;
614     illegal_request:
615         scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
616         scsi_req_complete(req, CHECK_CONDITION);
617         return 0;
618     }
619 
620     if (!r->len) {
621         scsi_req_complete(req, GOOD);
622     }
623     return r->len;
624 }
625 
626 static void scsi_target_read_data(SCSIRequest *req)
627 {
628     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
629     uint32_t n;
630 
631     n = r->len;
632     if (n > 0) {
633         r->len = 0;
634         scsi_req_data(&r->req, n);
635     } else {
636         scsi_req_complete(&r->req, GOOD);
637     }
638 }
639 
640 static uint8_t *scsi_target_get_buf(SCSIRequest *req)
641 {
642     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
643 
644     return r->buf;
645 }
646 
647 static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
648 {
649     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
650 
651     r->buf = g_malloc(len);
652     r->buf_len = len;
653 
654     return r->buf;
655 }
656 
657 static void scsi_target_free_buf(SCSIRequest *req)
658 {
659     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
660 
661     g_free(r->buf);
662 }
663 
664 static const struct SCSIReqOps reqops_target_command = {
665     .size         = sizeof(SCSITargetReq),
666     .send_command = scsi_target_send_command,
667     .read_data    = scsi_target_read_data,
668     .get_buf      = scsi_target_get_buf,
669     .free_req     = scsi_target_free_buf,
670 };
671 
672 
673 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
674                             uint32_t tag, uint32_t lun, void *hba_private)
675 {
676     SCSIRequest *req;
677     SCSIBus *bus = scsi_bus_from_device(d);
678     BusState *qbus = BUS(bus);
679     const int memset_off = offsetof(SCSIRequest, sense)
680                            + sizeof(req->sense);
681 
682     req = g_malloc(reqops->size);
683     memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
684     req->refcount = 1;
685     req->bus = bus;
686     req->dev = d;
687     req->tag = tag;
688     req->lun = lun;
689     req->hba_private = hba_private;
690     req->status = -1;
691     req->ops = reqops;
692     object_ref(OBJECT(d));
693     object_ref(OBJECT(qbus->parent));
694     notifier_list_init(&req->cancel_notifiers);
695     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
696     return req;
697 }
698 
699 SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
700                           uint8_t *buf, void *hba_private)
701 {
702     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
703     const SCSIReqOps *ops;
704     SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
705     SCSIRequest *req;
706     SCSICommand cmd = { .len = 0 };
707     int ret;
708 
709     if ((d->unit_attention.key == UNIT_ATTENTION ||
710          bus->unit_attention.key == UNIT_ATTENTION) &&
711         (buf[0] != INQUIRY &&
712          buf[0] != REPORT_LUNS &&
713          buf[0] != GET_CONFIGURATION &&
714          buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
715 
716          /*
717           * If we already have a pending unit attention condition,
718           * report this one before triggering another one.
719           */
720          !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
721         ops = &reqops_unit_attention;
722     } else if (lun != d->lun ||
723                buf[0] == REPORT_LUNS ||
724                (buf[0] == REQUEST_SENSE && d->sense_len)) {
725         ops = &reqops_target_command;
726     } else {
727         ops = NULL;
728     }
729 
730     if (ops != NULL || !sc->parse_cdb) {
731         ret = scsi_req_parse_cdb(d, &cmd, buf);
732     } else {
733         ret = sc->parse_cdb(d, &cmd, buf, hba_private);
734     }
735 
736     if (ret != 0) {
737         trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
738         req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
739     } else {
740         assert(cmd.len != 0);
741         trace_scsi_req_parsed(d->id, lun, tag, buf[0],
742                               cmd.mode, cmd.xfer);
743         if (cmd.lba != -1) {
744             trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
745                                       cmd.lba);
746         }
747 
748         if (cmd.xfer > INT32_MAX) {
749             req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
750         } else if (ops) {
751             req = scsi_req_alloc(ops, d, tag, lun, hba_private);
752         } else {
753             req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
754         }
755     }
756 
757     req->cmd = cmd;
758     req->resid = req->cmd.xfer;
759 
760     switch (buf[0]) {
761     case INQUIRY:
762         trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
763         break;
764     case TEST_UNIT_READY:
765         trace_scsi_test_unit_ready(d->id, lun, tag);
766         break;
767     case REPORT_LUNS:
768         trace_scsi_report_luns(d->id, lun, tag);
769         break;
770     case REQUEST_SENSE:
771         trace_scsi_request_sense(d->id, lun, tag);
772         break;
773     default:
774         break;
775     }
776 
777     return req;
778 }
779 
780 uint8_t *scsi_req_get_buf(SCSIRequest *req)
781 {
782     return req->ops->get_buf(req);
783 }
784 
785 static void scsi_clear_unit_attention(SCSIRequest *req)
786 {
787     SCSISense *ua;
788     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
789         req->bus->unit_attention.key != UNIT_ATTENTION) {
790         return;
791     }
792 
793     /*
794      * If an INQUIRY command enters the enabled command state,
795      * the device server shall [not] clear any unit attention condition;
796      * See also MMC-6, paragraphs 6.5 and 6.6.2.
797      */
798     if (req->cmd.buf[0] == INQUIRY ||
799         req->cmd.buf[0] == GET_CONFIGURATION ||
800         req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
801         return;
802     }
803 
804     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
805         ua = &req->dev->unit_attention;
806     } else {
807         ua = &req->bus->unit_attention;
808     }
809 
810     /*
811      * If a REPORT LUNS command enters the enabled command state, [...]
812      * the device server shall clear any pending unit attention condition
813      * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
814      */
815     if (req->cmd.buf[0] == REPORT_LUNS &&
816         !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
817           ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
818         return;
819     }
820 
821     *ua = SENSE_CODE(NO_SENSE);
822 }
823 
824 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
825 {
826     int ret;
827 
828     assert(len >= 14);
829     if (!req->sense_len) {
830         return 0;
831     }
832 
833     ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
834 
835     /*
836      * FIXME: clearing unit attention conditions upon autosense should be done
837      * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
838      * (SAM-5, 5.14).
839      *
840      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
841      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
842      * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
843      */
844     if (req->dev->sense_is_ua) {
845         scsi_device_unit_attention_reported(req->dev);
846         req->dev->sense_len = 0;
847         req->dev->sense_is_ua = false;
848     }
849     return ret;
850 }
851 
852 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
853 {
854     return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
855 }
856 
857 void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
858 {
859     trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
860                                sense.key, sense.asc, sense.ascq);
861     req->sense_len = scsi_build_sense(req->sense, sense);
862 }
863 
864 static void scsi_req_enqueue_internal(SCSIRequest *req)
865 {
866     assert(!req->enqueued);
867     scsi_req_ref(req);
868     if (req->bus->info->get_sg_list) {
869         req->sg = req->bus->info->get_sg_list(req);
870     } else {
871         req->sg = NULL;
872     }
873     req->enqueued = true;
874     QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
875 }
876 
877 int32_t scsi_req_enqueue(SCSIRequest *req)
878 {
879     int32_t rc;
880 
881     assert(!req->retry);
882     scsi_req_enqueue_internal(req);
883     scsi_req_ref(req);
884     rc = req->ops->send_command(req, req->cmd.buf);
885     scsi_req_unref(req);
886     return rc;
887 }
888 
889 static void scsi_req_dequeue(SCSIRequest *req)
890 {
891     trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
892     req->retry = false;
893     if (req->enqueued) {
894         QTAILQ_REMOVE(&req->dev->requests, req, next);
895         req->enqueued = false;
896         scsi_req_unref(req);
897     }
898 }
899 
900 static int scsi_get_performance_length(int num_desc, int type, int data_type)
901 {
902     /* MMC-6, paragraph 6.7.  */
903     switch (type) {
904     case 0:
905         if ((data_type & 3) == 0) {
906             /* Each descriptor is as in Table 295 - Nominal performance.  */
907             return 16 * num_desc + 8;
908         } else {
909             /* Each descriptor is as in Table 296 - Exceptions.  */
910             return 6 * num_desc + 8;
911         }
912     case 1:
913     case 4:
914     case 5:
915         return 8 * num_desc + 8;
916     case 2:
917         return 2048 * num_desc + 8;
918     case 3:
919         return 16 * num_desc + 8;
920     default:
921         return 8;
922     }
923 }
924 
925 static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
926 {
927     int byte_block = (buf[2] >> 2) & 0x1;
928     int type = (buf[2] >> 4) & 0x1;
929     int xfer_unit;
930 
931     if (byte_block) {
932         if (type) {
933             xfer_unit = dev->blocksize;
934         } else {
935             xfer_unit = 512;
936         }
937     } else {
938         xfer_unit = 1;
939     }
940 
941     return xfer_unit;
942 }
943 
944 static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
945 {
946     int length = buf[2] & 0x3;
947     int xfer;
948     int unit = ata_passthrough_xfer_unit(dev, buf);
949 
950     switch (length) {
951     case 0:
952     case 3: /* USB-specific.  */
953     default:
954         xfer = 0;
955         break;
956     case 1:
957         xfer = buf[3];
958         break;
959     case 2:
960         xfer = buf[4];
961         break;
962     }
963 
964     return xfer * unit;
965 }
966 
967 static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
968 {
969     int extend = buf[1] & 0x1;
970     int length = buf[2] & 0x3;
971     int xfer;
972     int unit = ata_passthrough_xfer_unit(dev, buf);
973 
974     switch (length) {
975     case 0:
976     case 3: /* USB-specific.  */
977     default:
978         xfer = 0;
979         break;
980     case 1:
981         xfer = buf[4];
982         xfer |= (extend ? buf[3] << 8 : 0);
983         break;
984     case 2:
985         xfer = buf[6];
986         xfer |= (extend ? buf[5] << 8 : 0);
987         break;
988     }
989 
990     return xfer * unit;
991 }
992 
993 static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
994 {
995     cmd->xfer = scsi_cdb_xfer(buf);
996     switch (buf[0]) {
997     case TEST_UNIT_READY:
998     case REWIND:
999     case START_STOP:
1000     case SET_CAPACITY:
1001     case WRITE_FILEMARKS:
1002     case WRITE_FILEMARKS_16:
1003     case SPACE:
1004     case RESERVE:
1005     case RELEASE:
1006     case ERASE:
1007     case ALLOW_MEDIUM_REMOVAL:
1008     case SEEK_10:
1009     case SYNCHRONIZE_CACHE:
1010     case SYNCHRONIZE_CACHE_16:
1011     case LOCATE_16:
1012     case LOCK_UNLOCK_CACHE:
1013     case SET_CD_SPEED:
1014     case SET_LIMITS:
1015     case WRITE_LONG_10:
1016     case UPDATE_BLOCK:
1017     case RESERVE_TRACK:
1018     case SET_READ_AHEAD:
1019     case PRE_FETCH:
1020     case PRE_FETCH_16:
1021     case ALLOW_OVERWRITE:
1022         cmd->xfer = 0;
1023         break;
1024     case VERIFY_10:
1025     case VERIFY_12:
1026     case VERIFY_16:
1027         if ((buf[1] & 2) == 0) {
1028             cmd->xfer = 0;
1029         } else if ((buf[1] & 4) != 0) {
1030             cmd->xfer = 1;
1031         }
1032         cmd->xfer *= dev->blocksize;
1033         break;
1034     case MODE_SENSE:
1035         break;
1036     case WRITE_SAME_10:
1037     case WRITE_SAME_16:
1038         cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
1039         break;
1040     case READ_CAPACITY_10:
1041         cmd->xfer = 8;
1042         break;
1043     case READ_BLOCK_LIMITS:
1044         cmd->xfer = 6;
1045         break;
1046     case SEND_VOLUME_TAG:
1047         /* GPCMD_SET_STREAMING from multimedia commands.  */
1048         if (dev->type == TYPE_ROM) {
1049             cmd->xfer = buf[10] | (buf[9] << 8);
1050         } else {
1051             cmd->xfer = buf[9] | (buf[8] << 8);
1052         }
1053         break;
1054     case WRITE_6:
1055         /* length 0 means 256 blocks */
1056         if (cmd->xfer == 0) {
1057             cmd->xfer = 256;
1058         }
1059         /* fall through */
1060     case WRITE_10:
1061     case WRITE_VERIFY_10:
1062     case WRITE_12:
1063     case WRITE_VERIFY_12:
1064     case WRITE_16:
1065     case WRITE_VERIFY_16:
1066         cmd->xfer *= dev->blocksize;
1067         break;
1068     case READ_6:
1069     case READ_REVERSE:
1070         /* length 0 means 256 blocks */
1071         if (cmd->xfer == 0) {
1072             cmd->xfer = 256;
1073         }
1074         /* fall through */
1075     case READ_10:
1076     case READ_12:
1077     case READ_16:
1078         cmd->xfer *= dev->blocksize;
1079         break;
1080     case FORMAT_UNIT:
1081         /* MMC mandates the parameter list to be 12-bytes long.  Parameters
1082          * for block devices are restricted to the header right now.  */
1083         if (dev->type == TYPE_ROM && (buf[1] & 16)) {
1084             cmd->xfer = 12;
1085         } else {
1086             cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
1087         }
1088         break;
1089     case INQUIRY:
1090     case RECEIVE_DIAGNOSTIC:
1091     case SEND_DIAGNOSTIC:
1092         cmd->xfer = buf[4] | (buf[3] << 8);
1093         break;
1094     case READ_CD:
1095     case READ_BUFFER:
1096     case WRITE_BUFFER:
1097     case SEND_CUE_SHEET:
1098         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1099         break;
1100     case PERSISTENT_RESERVE_OUT:
1101         cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
1102         break;
1103     case ERASE_12:
1104         if (dev->type == TYPE_ROM) {
1105             /* MMC command GET PERFORMANCE.  */
1106             cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
1107                                                     buf[10], buf[1] & 0x1f);
1108         }
1109         break;
1110     case MECHANISM_STATUS:
1111     case READ_DVD_STRUCTURE:
1112     case SEND_DVD_STRUCTURE:
1113     case MAINTENANCE_OUT:
1114     case MAINTENANCE_IN:
1115         if (dev->type == TYPE_ROM) {
1116             /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
1117             cmd->xfer = buf[9] | (buf[8] << 8);
1118         }
1119         break;
1120     case ATA_PASSTHROUGH_12:
1121         if (dev->type == TYPE_ROM) {
1122             /* BLANK command of MMC */
1123             cmd->xfer = 0;
1124         } else {
1125             cmd->xfer = ata_passthrough_12_xfer(dev, buf);
1126         }
1127         break;
1128     case ATA_PASSTHROUGH_16:
1129         cmd->xfer = ata_passthrough_16_xfer(dev, buf);
1130         break;
1131     }
1132     return 0;
1133 }
1134 
1135 static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1136 {
1137     switch (buf[0]) {
1138     /* stream commands */
1139     case ERASE_12:
1140     case ERASE_16:
1141         cmd->xfer = 0;
1142         break;
1143     case READ_6:
1144     case READ_REVERSE:
1145     case RECOVER_BUFFERED_DATA:
1146     case WRITE_6:
1147         cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
1148         if (buf[1] & 0x01) { /* fixed */
1149             cmd->xfer *= dev->blocksize;
1150         }
1151         break;
1152     case READ_16:
1153     case READ_REVERSE_16:
1154     case VERIFY_16:
1155     case WRITE_16:
1156         cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
1157         if (buf[1] & 0x01) { /* fixed */
1158             cmd->xfer *= dev->blocksize;
1159         }
1160         break;
1161     case REWIND:
1162     case LOAD_UNLOAD:
1163         cmd->xfer = 0;
1164         break;
1165     case SPACE_16:
1166         cmd->xfer = buf[13] | (buf[12] << 8);
1167         break;
1168     case READ_POSITION:
1169         switch (buf[1] & 0x1f) /* operation code */ {
1170         case SHORT_FORM_BLOCK_ID:
1171         case SHORT_FORM_VENDOR_SPECIFIC:
1172             cmd->xfer = 20;
1173             break;
1174         case LONG_FORM:
1175             cmd->xfer = 32;
1176             break;
1177         case EXTENDED_FORM:
1178             cmd->xfer = buf[8] | (buf[7] << 8);
1179             break;
1180         default:
1181             return -1;
1182         }
1183 
1184         break;
1185     case FORMAT_UNIT:
1186         cmd->xfer = buf[4] | (buf[3] << 8);
1187         break;
1188     /* generic commands */
1189     default:
1190         return scsi_req_xfer(cmd, dev, buf);
1191     }
1192     return 0;
1193 }
1194 
1195 static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1196 {
1197     switch (buf[0]) {
1198     /* medium changer commands */
1199     case EXCHANGE_MEDIUM:
1200     case INITIALIZE_ELEMENT_STATUS:
1201     case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
1202     case MOVE_MEDIUM:
1203     case POSITION_TO_ELEMENT:
1204         cmd->xfer = 0;
1205         break;
1206     case READ_ELEMENT_STATUS:
1207         cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
1208         break;
1209 
1210     /* generic commands */
1211     default:
1212         return scsi_req_xfer(cmd, dev, buf);
1213     }
1214     return 0;
1215 }
1216 
1217 static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
1218 {
1219     switch (buf[0]) {
1220     /* Scanner commands */
1221     case OBJECT_POSITION:
1222         cmd->xfer = 0;
1223         break;
1224     case SCAN:
1225         cmd->xfer = buf[4];
1226         break;
1227     case READ_10:
1228     case SEND:
1229     case GET_WINDOW:
1230     case SET_WINDOW:
1231         cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
1232         break;
1233     default:
1234         /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
1235         return scsi_req_xfer(cmd, dev, buf);
1236     }
1237 
1238     return 0;
1239 }
1240 
1241 static void scsi_cmd_xfer_mode(SCSICommand *cmd)
1242 {
1243     if (!cmd->xfer) {
1244         cmd->mode = SCSI_XFER_NONE;
1245         return;
1246     }
1247     switch (cmd->buf[0]) {
1248     case WRITE_6:
1249     case WRITE_10:
1250     case WRITE_VERIFY_10:
1251     case WRITE_12:
1252     case WRITE_VERIFY_12:
1253     case WRITE_16:
1254     case WRITE_VERIFY_16:
1255     case VERIFY_10:
1256     case VERIFY_12:
1257     case VERIFY_16:
1258     case COPY:
1259     case COPY_VERIFY:
1260     case COMPARE:
1261     case CHANGE_DEFINITION:
1262     case LOG_SELECT:
1263     case MODE_SELECT:
1264     case MODE_SELECT_10:
1265     case SEND_DIAGNOSTIC:
1266     case WRITE_BUFFER:
1267     case FORMAT_UNIT:
1268     case REASSIGN_BLOCKS:
1269     case SEARCH_EQUAL:
1270     case SEARCH_HIGH:
1271     case SEARCH_LOW:
1272     case UPDATE_BLOCK:
1273     case WRITE_LONG_10:
1274     case WRITE_SAME_10:
1275     case WRITE_SAME_16:
1276     case UNMAP:
1277     case SEARCH_HIGH_12:
1278     case SEARCH_EQUAL_12:
1279     case SEARCH_LOW_12:
1280     case MEDIUM_SCAN:
1281     case SEND_VOLUME_TAG:
1282     case SEND_CUE_SHEET:
1283     case SEND_DVD_STRUCTURE:
1284     case PERSISTENT_RESERVE_OUT:
1285     case MAINTENANCE_OUT:
1286     case SET_WINDOW:
1287     case SCAN:
1288         /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
1289          * non-scanner devices, so we only get here for SCAN and not for START_STOP.
1290          */
1291         cmd->mode = SCSI_XFER_TO_DEV;
1292         break;
1293     case ATA_PASSTHROUGH_12:
1294     case ATA_PASSTHROUGH_16:
1295         /* T_DIR */
1296         cmd->mode = (cmd->buf[2] & 0x8) ?
1297                    SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
1298         break;
1299     default:
1300         cmd->mode = SCSI_XFER_FROM_DEV;
1301         break;
1302     }
1303 }
1304 
1305 int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf)
1306 {
1307     int rc;
1308     int len;
1309 
1310     cmd->lba = -1;
1311     len = scsi_cdb_length(buf);
1312     if (len < 0) {
1313         return -1;
1314     }
1315 
1316     cmd->len = len;
1317     switch (dev->type) {
1318     case TYPE_TAPE:
1319         rc = scsi_req_stream_xfer(cmd, dev, buf);
1320         break;
1321     case TYPE_MEDIUM_CHANGER:
1322         rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
1323         break;
1324     case TYPE_SCANNER:
1325         rc = scsi_req_scanner_length(cmd, dev, buf);
1326         break;
1327     default:
1328         rc = scsi_req_xfer(cmd, dev, buf);
1329         break;
1330     }
1331 
1332     if (rc != 0)
1333         return rc;
1334 
1335     memcpy(cmd->buf, buf, cmd->len);
1336     scsi_cmd_xfer_mode(cmd);
1337     cmd->lba = scsi_cmd_lba(cmd);
1338     return 0;
1339 }
1340 
1341 void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
1342 {
1343     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
1344 
1345     scsi_device_set_ua(dev, sense);
1346     if (bus->info->change) {
1347         bus->info->change(bus, dev, sense);
1348     }
1349 }
1350 
1351 SCSIRequest *scsi_req_ref(SCSIRequest *req)
1352 {
1353     assert(req->refcount > 0);
1354     req->refcount++;
1355     return req;
1356 }
1357 
1358 void scsi_req_unref(SCSIRequest *req)
1359 {
1360     assert(req->refcount > 0);
1361     if (--req->refcount == 0) {
1362         BusState *qbus = req->dev->qdev.parent_bus;
1363         SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
1364 
1365         if (bus->info->free_request && req->hba_private) {
1366             bus->info->free_request(bus, req->hba_private);
1367         }
1368         if (req->ops->free_req) {
1369             req->ops->free_req(req);
1370         }
1371         object_unref(OBJECT(req->dev));
1372         object_unref(OBJECT(qbus->parent));
1373         g_free(req);
1374     }
1375 }
1376 
1377 /* Tell the device that we finished processing this chunk of I/O.  It
1378    will start the next chunk or complete the command.  */
1379 void scsi_req_continue(SCSIRequest *req)
1380 {
1381     if (req->io_canceled) {
1382         trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
1383         return;
1384     }
1385     trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
1386     if (req->cmd.mode == SCSI_XFER_TO_DEV) {
1387         req->ops->write_data(req);
1388     } else {
1389         req->ops->read_data(req);
1390     }
1391 }
1392 
1393 /* Called by the devices when data is ready for the HBA.  The HBA should
1394    start a DMA operation to read or fill the device's data buffer.
1395    Once it completes, calling scsi_req_continue will restart I/O.  */
1396 void scsi_req_data(SCSIRequest *req, int len)
1397 {
1398     uint8_t *buf;
1399     if (req->io_canceled) {
1400         trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
1401         return;
1402     }
1403     trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
1404     assert(req->cmd.mode != SCSI_XFER_NONE);
1405     if (!req->sg) {
1406         req->resid -= len;
1407         req->bus->info->transfer_data(req, len);
1408         return;
1409     }
1410 
1411     /* If the device calls scsi_req_data and the HBA specified a
1412      * scatter/gather list, the transfer has to happen in a single
1413      * step.  */
1414     assert(!req->dma_started);
1415     req->dma_started = true;
1416 
1417     buf = scsi_req_get_buf(req);
1418     if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
1419         req->resid = dma_buf_read(buf, len, req->sg);
1420     } else {
1421         req->resid = dma_buf_write(buf, len, req->sg);
1422     }
1423     scsi_req_continue(req);
1424 }
1425 
1426 void scsi_req_print(SCSIRequest *req)
1427 {
1428     FILE *fp = stderr;
1429     int i;
1430 
1431     fprintf(fp, "[%s id=%d] %s",
1432             req->dev->qdev.parent_bus->name,
1433             req->dev->id,
1434             scsi_command_name(req->cmd.buf[0]));
1435     for (i = 1; i < req->cmd.len; i++) {
1436         fprintf(fp, " 0x%02x", req->cmd.buf[i]);
1437     }
1438     switch (req->cmd.mode) {
1439     case SCSI_XFER_NONE:
1440         fprintf(fp, " - none\n");
1441         break;
1442     case SCSI_XFER_FROM_DEV:
1443         fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
1444         break;
1445     case SCSI_XFER_TO_DEV:
1446         fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
1447         break;
1448     default:
1449         fprintf(fp, " - Oops\n");
1450         break;
1451     }
1452 }
1453 
1454 void scsi_req_complete(SCSIRequest *req, int status)
1455 {
1456     assert(req->status == -1);
1457     req->status = status;
1458 
1459     assert(req->sense_len <= sizeof(req->sense));
1460     if (status == GOOD) {
1461         req->sense_len = 0;
1462     }
1463 
1464     if (req->sense_len) {
1465         memcpy(req->dev->sense, req->sense, req->sense_len);
1466         req->dev->sense_len = req->sense_len;
1467         req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
1468     } else {
1469         req->dev->sense_len = 0;
1470         req->dev->sense_is_ua = false;
1471     }
1472 
1473     /*
1474      * Unit attention state is now stored in the device's sense buffer
1475      * if the HBA didn't do autosense.  Clear the pending unit attention
1476      * flags.
1477      */
1478     scsi_clear_unit_attention(req);
1479 
1480     scsi_req_ref(req);
1481     scsi_req_dequeue(req);
1482     req->bus->info->complete(req, req->status, req->resid);
1483 
1484     /* Cancelled requests might end up being completed instead of cancelled */
1485     notifier_list_notify(&req->cancel_notifiers, req);
1486     scsi_req_unref(req);
1487 }
1488 
1489 /* Called by the devices when the request is canceled. */
1490 void scsi_req_cancel_complete(SCSIRequest *req)
1491 {
1492     assert(req->io_canceled);
1493     if (req->bus->info->cancel) {
1494         req->bus->info->cancel(req);
1495     }
1496     notifier_list_notify(&req->cancel_notifiers, req);
1497     scsi_req_unref(req);
1498 }
1499 
1500 /* Cancel @req asynchronously. @notifier is added to @req's cancellation
1501  * notifier list, the bus will be notified the requests cancellation is
1502  * completed.
1503  * */
1504 void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
1505 {
1506     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1507     if (notifier) {
1508         notifier_list_add(&req->cancel_notifiers, notifier);
1509     }
1510     if (req->io_canceled) {
1511         /* A blk_aio_cancel_async is pending; when it finishes,
1512          * scsi_req_cancel_complete will be called and will
1513          * call the notifier we just added.  Just wait for that.
1514          */
1515         assert(req->aiocb);
1516         return;
1517     }
1518     /* Dropped in scsi_req_cancel_complete.  */
1519     scsi_req_ref(req);
1520     scsi_req_dequeue(req);
1521     req->io_canceled = true;
1522     if (req->aiocb) {
1523         blk_aio_cancel_async(req->aiocb);
1524     } else {
1525         scsi_req_cancel_complete(req);
1526     }
1527 }
1528 
1529 void scsi_req_cancel(SCSIRequest *req)
1530 {
1531     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
1532     if (!req->enqueued) {
1533         return;
1534     }
1535     assert(!req->io_canceled);
1536     /* Dropped in scsi_req_cancel_complete.  */
1537     scsi_req_ref(req);
1538     scsi_req_dequeue(req);
1539     req->io_canceled = true;
1540     if (req->aiocb) {
1541         blk_aio_cancel(req->aiocb);
1542     } else {
1543         scsi_req_cancel_complete(req);
1544     }
1545 }
1546 
1547 static int scsi_ua_precedence(SCSISense sense)
1548 {
1549     if (sense.key != UNIT_ATTENTION) {
1550         return INT_MAX;
1551     }
1552     if (sense.asc == 0x29 && sense.ascq == 0x04) {
1553         /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
1554         return 1;
1555     } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
1556         /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
1557         return 2;
1558     } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
1559         /* These two go with "all others". */
1560         ;
1561     } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
1562         /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
1563          * POWER ON OCCURRED = 1
1564          * SCSI BUS RESET OCCURRED = 2
1565          * BUS DEVICE RESET FUNCTION OCCURRED = 3
1566          * I_T NEXUS LOSS OCCURRED = 7
1567          */
1568         return sense.ascq;
1569     } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
1570         /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
1571         return 8;
1572     }
1573     return (sense.asc << 8) | sense.ascq;
1574 }
1575 
1576 void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
1577 {
1578     int prec1, prec2;
1579     if (sense.key != UNIT_ATTENTION) {
1580         return;
1581     }
1582     trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
1583                              sense.asc, sense.ascq);
1584 
1585     /*
1586      * Override a pre-existing unit attention condition, except for a more
1587      * important reset condition.
1588     */
1589     prec1 = scsi_ua_precedence(sdev->unit_attention);
1590     prec2 = scsi_ua_precedence(sense);
1591     if (prec2 < prec1) {
1592         sdev->unit_attention = sense;
1593     }
1594 }
1595 
1596 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
1597 {
1598     SCSIRequest *req;
1599 
1600     aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
1601     while (!QTAILQ_EMPTY(&sdev->requests)) {
1602         req = QTAILQ_FIRST(&sdev->requests);
1603         scsi_req_cancel_async(req, NULL);
1604     }
1605     blk_drain(sdev->conf.blk);
1606     aio_context_release(blk_get_aio_context(sdev->conf.blk));
1607     scsi_device_set_ua(sdev, sense);
1608 }
1609 
1610 static char *scsibus_get_dev_path(DeviceState *dev)
1611 {
1612     SCSIDevice *d = SCSI_DEVICE(dev);
1613     DeviceState *hba = dev->parent_bus->parent;
1614     char *id;
1615     char *path;
1616 
1617     id = qdev_get_dev_path(hba);
1618     if (id) {
1619         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
1620     } else {
1621         path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
1622     }
1623     g_free(id);
1624     return path;
1625 }
1626 
1627 static char *scsibus_get_fw_dev_path(DeviceState *dev)
1628 {
1629     SCSIDevice *d = SCSI_DEVICE(dev);
1630     return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
1631                            qdev_fw_name(dev), d->id, d->lun);
1632 }
1633 
1634 /* SCSI request list.  For simplicity, pv points to the whole device */
1635 
1636 static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
1637                              const VMStateField *field, QJSON *vmdesc)
1638 {
1639     SCSIDevice *s = pv;
1640     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1641     SCSIRequest *req;
1642 
1643     QTAILQ_FOREACH(req, &s->requests, next) {
1644         assert(!req->io_canceled);
1645         assert(req->status == -1);
1646         assert(req->enqueued);
1647 
1648         qemu_put_sbyte(f, req->retry ? 1 : 2);
1649         qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
1650         qemu_put_be32s(f, &req->tag);
1651         qemu_put_be32s(f, &req->lun);
1652         if (bus->info->save_request) {
1653             bus->info->save_request(f, req);
1654         }
1655         if (req->ops->save_request) {
1656             req->ops->save_request(f, req);
1657         }
1658     }
1659     qemu_put_sbyte(f, 0);
1660 
1661     return 0;
1662 }
1663 
1664 static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
1665                              const VMStateField *field)
1666 {
1667     SCSIDevice *s = pv;
1668     SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
1669     int8_t sbyte;
1670 
1671     while ((sbyte = qemu_get_sbyte(f)) > 0) {
1672         uint8_t buf[SCSI_CMD_BUF_SIZE];
1673         uint32_t tag;
1674         uint32_t lun;
1675         SCSIRequest *req;
1676 
1677         qemu_get_buffer(f, buf, sizeof(buf));
1678         qemu_get_be32s(f, &tag);
1679         qemu_get_be32s(f, &lun);
1680         req = scsi_req_new(s, tag, lun, buf, NULL);
1681         req->retry = (sbyte == 1);
1682         if (bus->info->load_request) {
1683             req->hba_private = bus->info->load_request(f, req);
1684         }
1685         if (req->ops->load_request) {
1686             req->ops->load_request(f, req);
1687         }
1688 
1689         /* Just restart it later.  */
1690         scsi_req_enqueue_internal(req);
1691 
1692         /* At this point, the request will be kept alive by the reference
1693          * added by scsi_req_enqueue_internal, so we can release our reference.
1694          * The HBA of course will add its own reference in the load_request
1695          * callback if it needs to hold on the SCSIRequest.
1696          */
1697         scsi_req_unref(req);
1698     }
1699 
1700     return 0;
1701 }
1702 
1703 static const VMStateInfo vmstate_info_scsi_requests = {
1704     .name = "scsi-requests",
1705     .get  = get_scsi_requests,
1706     .put  = put_scsi_requests,
1707 };
1708 
1709 static bool scsi_sense_state_needed(void *opaque)
1710 {
1711     SCSIDevice *s = opaque;
1712 
1713     return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
1714 }
1715 
1716 static const VMStateDescription vmstate_scsi_sense_state = {
1717     .name = "SCSIDevice/sense",
1718     .version_id = 1,
1719     .minimum_version_id = 1,
1720     .needed = scsi_sense_state_needed,
1721     .fields = (VMStateField[]) {
1722         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
1723                                 SCSI_SENSE_BUF_SIZE_OLD,
1724                                 SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
1725         VMSTATE_END_OF_LIST()
1726     }
1727 };
1728 
1729 const VMStateDescription vmstate_scsi_device = {
1730     .name = "SCSIDevice",
1731     .version_id = 1,
1732     .minimum_version_id = 1,
1733     .fields = (VMStateField[]) {
1734         VMSTATE_UINT8(unit_attention.key, SCSIDevice),
1735         VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
1736         VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
1737         VMSTATE_BOOL(sense_is_ua, SCSIDevice),
1738         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
1739         VMSTATE_UINT32(sense_len, SCSIDevice),
1740         {
1741             .name         = "requests",
1742             .version_id   = 0,
1743             .field_exists = NULL,
1744             .size         = 0,   /* ouch */
1745             .info         = &vmstate_info_scsi_requests,
1746             .flags        = VMS_SINGLE,
1747             .offset       = 0,
1748         },
1749         VMSTATE_END_OF_LIST()
1750     },
1751     .subsections = (const VMStateDescription*[]) {
1752         &vmstate_scsi_sense_state,
1753         NULL
1754     }
1755 };
1756 
1757 static Property scsi_props[] = {
1758     DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
1759     DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
1760     DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
1761     DEFINE_PROP_END_OF_LIST(),
1762 };
1763 
1764 static void scsi_device_class_init(ObjectClass *klass, void *data)
1765 {
1766     DeviceClass *k = DEVICE_CLASS(klass);
1767     set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
1768     k->bus_type  = TYPE_SCSI_BUS;
1769     k->realize   = scsi_qdev_realize;
1770     k->unrealize = scsi_qdev_unrealize;
1771     device_class_set_props(k, scsi_props);
1772 }
1773 
1774 static void scsi_dev_instance_init(Object *obj)
1775 {
1776     DeviceState *dev = DEVICE(obj);
1777     SCSIDevice *s = SCSI_DEVICE(dev);
1778 
1779     device_add_bootindex_property(obj, &s->conf.bootindex,
1780                                   "bootindex", NULL,
1781                                   &s->qdev);
1782 }
1783 
1784 static const TypeInfo scsi_device_type_info = {
1785     .name = TYPE_SCSI_DEVICE,
1786     .parent = TYPE_DEVICE,
1787     .instance_size = sizeof(SCSIDevice),
1788     .abstract = true,
1789     .class_size = sizeof(SCSIDeviceClass),
1790     .class_init = scsi_device_class_init,
1791     .instance_init = scsi_dev_instance_init,
1792 };
1793 
1794 static void scsi_bus_class_init(ObjectClass *klass, void *data)
1795 {
1796     BusClass *k = BUS_CLASS(klass);
1797     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1798 
1799     k->get_dev_path = scsibus_get_dev_path;
1800     k->get_fw_dev_path = scsibus_get_fw_dev_path;
1801     k->check_address = scsi_bus_check_address;
1802     hc->unplug = qdev_simple_device_unplug_cb;
1803 }
1804 
1805 static const TypeInfo scsi_bus_info = {
1806     .name = TYPE_SCSI_BUS,
1807     .parent = TYPE_BUS,
1808     .instance_size = sizeof(SCSIBus),
1809     .class_init = scsi_bus_class_init,
1810     .interfaces = (InterfaceInfo[]) {
1811         { TYPE_HOTPLUG_HANDLER },
1812         { }
1813     }
1814 };
1815 
1816 static void scsi_register_types(void)
1817 {
1818     type_register_static(&scsi_bus_info);
1819     type_register_static(&scsi_device_type_info);
1820 }
1821 
1822 type_init(scsi_register_types)
1823