xref: /openbmc/qemu/hw/scsi/virtio-scsi.c (revision 259ebed4)
1 /*
2  * Virtio SCSI HBA
3  *
4  * Copyright IBM, Corp. 2010
5  * Copyright Red Hat, Inc. 2011
6  *
7  * Authors:
8  *   Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
9  *   Paolo Bonzini      <pbonzini@redhat.com>
10  *
11  * This work is licensed under the terms of the GNU GPL, version 2 or later.
12  * See the COPYING file in the top-level directory.
13  *
14  */
15 
16 #include "qemu/osdep.h"
17 #include "qapi/error.h"
18 #include "standard-headers/linux/virtio_ids.h"
19 #include "hw/virtio/virtio-scsi.h"
20 #include "migration/qemu-file-types.h"
21 #include "qemu/defer-call.h"
22 #include "qemu/error-report.h"
23 #include "qemu/iov.h"
24 #include "qemu/module.h"
25 #include "sysemu/block-backend.h"
26 #include "sysemu/dma.h"
27 #include "hw/qdev-properties.h"
28 #include "hw/scsi/scsi.h"
29 #include "scsi/constants.h"
30 #include "hw/virtio/virtio-bus.h"
31 #include "hw/virtio/virtio-access.h"
32 #include "trace.h"
33 
34 typedef struct VirtIOSCSIReq {
35     /*
36      * Note:
37      * - fields up to resp_iov are initialized by virtio_scsi_init_req;
38      * - fields starting at vring are zeroed by virtio_scsi_init_req.
39      */
40     VirtQueueElement elem;
41 
42     VirtIOSCSI *dev;
43     VirtQueue *vq;
44     QEMUSGList qsgl;
45     QEMUIOVector resp_iov;
46 
47     /* Used for two-stage request submission and TMFs deferred to BH */
48     QTAILQ_ENTRY(VirtIOSCSIReq) next;
49 
50     /* Used for cancellation of request during TMFs */
51     int remaining;
52 
53     SCSIRequest *sreq;
54     size_t resp_size;
55     enum SCSIXferMode mode;
56     union {
57         VirtIOSCSICmdResp     cmd;
58         VirtIOSCSICtrlTMFResp tmf;
59         VirtIOSCSICtrlANResp  an;
60         VirtIOSCSIEvent       event;
61     } resp;
62     union {
63         VirtIOSCSICmdReq      cmd;
64         VirtIOSCSICtrlTMFReq  tmf;
65         VirtIOSCSICtrlANReq   an;
66     } req;
67 } VirtIOSCSIReq;
68 
69 static inline int virtio_scsi_get_lun(uint8_t *lun)
70 {
71     return ((lun[2] << 8) | lun[3]) & 0x3FFF;
72 }
73 
74 static inline SCSIDevice *virtio_scsi_device_get(VirtIOSCSI *s, uint8_t *lun)
75 {
76     if (lun[0] != 1) {
77         return NULL;
78     }
79     if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
80         return NULL;
81     }
82     return scsi_device_get(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
83 }
84 
85 static void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
86 {
87     VirtIODevice *vdev = VIRTIO_DEVICE(s);
88     const size_t zero_skip =
89         offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
90 
91     req->vq = vq;
92     req->dev = s;
93     qemu_sglist_init(&req->qsgl, DEVICE(s), 8, vdev->dma_as);
94     qemu_iovec_init(&req->resp_iov, 1);
95     memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
96 }
97 
98 static void virtio_scsi_free_req(VirtIOSCSIReq *req)
99 {
100     qemu_iovec_destroy(&req->resp_iov);
101     qemu_sglist_destroy(&req->qsgl);
102     g_free(req);
103 }
104 
105 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
106 {
107     VirtIOSCSI *s = req->dev;
108     VirtQueue *vq = req->vq;
109     VirtIODevice *vdev = VIRTIO_DEVICE(s);
110 
111     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
112     virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
113     if (s->dataplane_started && !s->dataplane_fenced) {
114         virtio_notify_irqfd(vdev, vq);
115     } else {
116         virtio_notify(vdev, vq);
117     }
118 
119     if (req->sreq) {
120         req->sreq->hba_private = NULL;
121         scsi_req_unref(req->sreq);
122     }
123     virtio_scsi_free_req(req);
124 }
125 
126 static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
127 {
128     virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
129     virtqueue_detach_element(req->vq, &req->elem, 0);
130     virtio_scsi_free_req(req);
131 }
132 
133 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
134                               hwaddr *addr, int num, size_t skip)
135 {
136     QEMUSGList *qsgl = &req->qsgl;
137     size_t copied = 0;
138 
139     while (num) {
140         if (skip >= iov->iov_len) {
141             skip -= iov->iov_len;
142         } else {
143             qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
144             copied += iov->iov_len - skip;
145             skip = 0;
146         }
147         iov++;
148         addr++;
149         num--;
150     }
151 
152     assert(skip == 0);
153     return copied;
154 }
155 
156 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
157                                  unsigned req_size, unsigned resp_size)
158 {
159     VirtIODevice *vdev = (VirtIODevice *) req->dev;
160     size_t in_size, out_size;
161 
162     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
163                    &req->req, req_size) < req_size) {
164         return -EINVAL;
165     }
166 
167     if (qemu_iovec_concat_iov(&req->resp_iov,
168                               req->elem.in_sg, req->elem.in_num, 0,
169                               resp_size) < resp_size) {
170         return -EINVAL;
171     }
172 
173     req->resp_size = resp_size;
174 
175     /* Old BIOSes left some padding by mistake after the req_size/resp_size.
176      * As a workaround, always consider the first buffer as the virtio-scsi
177      * request/response, making the payload start at the second element
178      * of the iovec.
179      *
180      * The actual length of the response header, stored in req->resp_size,
181      * does not change.
182      *
183      * TODO: always disable this workaround for virtio 1.0 devices.
184      */
185     if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
186         if (req->elem.out_num) {
187             req_size = req->elem.out_sg[0].iov_len;
188         }
189         if (req->elem.in_num) {
190             resp_size = req->elem.in_sg[0].iov_len;
191         }
192     }
193 
194     out_size = qemu_sgl_concat(req, req->elem.out_sg,
195                                &req->elem.out_addr[0], req->elem.out_num,
196                                req_size);
197     in_size = qemu_sgl_concat(req, req->elem.in_sg,
198                               &req->elem.in_addr[0], req->elem.in_num,
199                               resp_size);
200 
201     if (out_size && in_size) {
202         return -ENOTSUP;
203     }
204 
205     if (out_size) {
206         req->mode = SCSI_XFER_TO_DEV;
207     } else if (in_size) {
208         req->mode = SCSI_XFER_FROM_DEV;
209     }
210 
211     return 0;
212 }
213 
214 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
215 {
216     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
217     VirtIOSCSIReq *req;
218 
219     req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
220     if (!req) {
221         return NULL;
222     }
223     virtio_scsi_init_req(s, vq, req);
224     return req;
225 }
226 
227 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
228 {
229     VirtIOSCSIReq *req = sreq->hba_private;
230     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
231     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
232     uint32_t n = virtio_get_queue_index(req->vq) - VIRTIO_SCSI_VQ_NUM_FIXED;
233 
234     assert(n < vs->conf.num_queues);
235     qemu_put_be32s(f, &n);
236     qemu_put_virtqueue_element(vdev, f, &req->elem);
237 }
238 
239 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
240 {
241     SCSIBus *bus = sreq->bus;
242     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
243     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
244     VirtIODevice *vdev = VIRTIO_DEVICE(s);
245     VirtIOSCSIReq *req;
246     uint32_t n;
247 
248     qemu_get_be32s(f, &n);
249     assert(n < vs->conf.num_queues);
250     req = qemu_get_virtqueue_element(vdev, f,
251                                      sizeof(VirtIOSCSIReq) + vs->cdb_size);
252     virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
253 
254     if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
255                               sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
256         error_report("invalid SCSI request migration data");
257         exit(1);
258     }
259 
260     scsi_req_ref(sreq);
261     req->sreq = sreq;
262     if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
263         assert(req->sreq->cmd.mode == req->mode);
264     }
265     return req;
266 }
267 
268 typedef struct {
269     Notifier        notifier;
270     VirtIOSCSIReq  *tmf_req;
271 } VirtIOSCSICancelNotifier;
272 
273 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
274 {
275     VirtIOSCSICancelNotifier *n = container_of(notifier,
276                                                VirtIOSCSICancelNotifier,
277                                                notifier);
278 
279     if (--n->tmf_req->remaining == 0) {
280         VirtIOSCSIReq *req = n->tmf_req;
281 
282         trace_virtio_scsi_tmf_resp(virtio_scsi_get_lun(req->req.tmf.lun),
283                                    req->req.tmf.tag, req->resp.tmf.response);
284         virtio_scsi_complete_req(req);
285     }
286     g_free(n);
287 }
288 
289 static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
290 {
291     if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
292         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
293     }
294 }
295 
296 static void virtio_scsi_do_one_tmf_bh(VirtIOSCSIReq *req)
297 {
298     VirtIOSCSI *s = req->dev;
299     SCSIDevice *d = virtio_scsi_device_get(s, req->req.tmf.lun);
300     BusChild *kid;
301     int target;
302 
303     switch (req->req.tmf.subtype) {
304     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
305         if (!d) {
306             req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
307             goto out;
308         }
309         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
310             req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
311             goto out;
312         }
313         qatomic_inc(&s->resetting);
314         device_cold_reset(&d->qdev);
315         qatomic_dec(&s->resetting);
316         break;
317 
318     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
319         target = req->req.tmf.lun[1];
320         qatomic_inc(&s->resetting);
321 
322         rcu_read_lock();
323         QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) {
324             SCSIDevice *d1 = SCSI_DEVICE(kid->child);
325             if (d1->channel == 0 && d1->id == target) {
326                 device_cold_reset(&d1->qdev);
327             }
328         }
329         rcu_read_unlock();
330 
331         qatomic_dec(&s->resetting);
332         break;
333 
334     default:
335         g_assert_not_reached();
336         break;
337     }
338 
339 out:
340     object_unref(OBJECT(d));
341 
342     virtio_scsi_acquire(s);
343     virtio_scsi_complete_req(req);
344     virtio_scsi_release(s);
345 }
346 
347 /* Some TMFs must be processed from the main loop thread */
348 static void virtio_scsi_do_tmf_bh(void *opaque)
349 {
350     VirtIOSCSI *s = opaque;
351     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
352     VirtIOSCSIReq *req;
353     VirtIOSCSIReq *tmp;
354 
355     GLOBAL_STATE_CODE();
356 
357     virtio_scsi_acquire(s);
358 
359     QTAILQ_FOREACH_SAFE(req, &s->tmf_bh_list, next, tmp) {
360         QTAILQ_REMOVE(&s->tmf_bh_list, req, next);
361         QTAILQ_INSERT_TAIL(&reqs, req, next);
362     }
363 
364     qemu_bh_delete(s->tmf_bh);
365     s->tmf_bh = NULL;
366 
367     virtio_scsi_release(s);
368 
369     QTAILQ_FOREACH_SAFE(req, &reqs, next, tmp) {
370         QTAILQ_REMOVE(&reqs, req, next);
371         virtio_scsi_do_one_tmf_bh(req);
372     }
373 }
374 
375 static void virtio_scsi_reset_tmf_bh(VirtIOSCSI *s)
376 {
377     VirtIOSCSIReq *req;
378     VirtIOSCSIReq *tmp;
379 
380     GLOBAL_STATE_CODE();
381 
382     virtio_scsi_acquire(s);
383 
384     if (s->tmf_bh) {
385         qemu_bh_delete(s->tmf_bh);
386         s->tmf_bh = NULL;
387     }
388 
389     QTAILQ_FOREACH_SAFE(req, &s->tmf_bh_list, next, tmp) {
390         QTAILQ_REMOVE(&s->tmf_bh_list, req, next);
391 
392         /* SAM-6 6.3.2 Hard reset */
393         req->resp.tmf.response = VIRTIO_SCSI_S_TARGET_FAILURE;
394         virtio_scsi_complete_req(req);
395     }
396 
397     virtio_scsi_release(s);
398 }
399 
400 static void virtio_scsi_defer_tmf_to_bh(VirtIOSCSIReq *req)
401 {
402     VirtIOSCSI *s = req->dev;
403 
404     QTAILQ_INSERT_TAIL(&s->tmf_bh_list, req, next);
405 
406     if (!s->tmf_bh) {
407         s->tmf_bh = qemu_bh_new(virtio_scsi_do_tmf_bh, s);
408         qemu_bh_schedule(s->tmf_bh);
409     }
410 }
411 
412 /* Return 0 if the request is ready to be completed and return to guest;
413  * -EINPROGRESS if the request is submitted and will be completed later, in the
414  *  case of async cancellation. */
415 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
416 {
417     SCSIDevice *d = virtio_scsi_device_get(s, req->req.tmf.lun);
418     SCSIRequest *r, *next;
419     int ret = 0;
420 
421     virtio_scsi_ctx_check(s, d);
422     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */
423     req->resp.tmf.response = VIRTIO_SCSI_S_OK;
424 
425     /*
426      * req->req.tmf has the QEMU_PACKED attribute. Don't use virtio_tswap32s()
427      * to avoid compiler errors.
428      */
429     req->req.tmf.subtype =
430         virtio_tswap32(VIRTIO_DEVICE(s), req->req.tmf.subtype);
431 
432     trace_virtio_scsi_tmf_req(virtio_scsi_get_lun(req->req.tmf.lun),
433                               req->req.tmf.tag, req->req.tmf.subtype);
434 
435     switch (req->req.tmf.subtype) {
436     case VIRTIO_SCSI_T_TMF_ABORT_TASK:
437     case VIRTIO_SCSI_T_TMF_QUERY_TASK:
438         if (!d) {
439             goto fail;
440         }
441         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
442             goto incorrect_lun;
443         }
444         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
445             VirtIOSCSIReq *cmd_req = r->hba_private;
446             if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
447                 break;
448             }
449         }
450         if (r) {
451             /*
452              * Assert that the request has not been completed yet, we
453              * check for it in the loop above.
454              */
455             assert(r->hba_private);
456             if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
457                 /* "If the specified command is present in the task set, then
458                  * return a service response set to FUNCTION SUCCEEDED".
459                  */
460                 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
461             } else {
462                 VirtIOSCSICancelNotifier *notifier;
463 
464                 req->remaining = 1;
465                 notifier = g_new(VirtIOSCSICancelNotifier, 1);
466                 notifier->tmf_req = req;
467                 notifier->notifier.notify = virtio_scsi_cancel_notify;
468                 scsi_req_cancel_async(r, &notifier->notifier);
469                 ret = -EINPROGRESS;
470             }
471         }
472         break;
473 
474     case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
475     case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
476         virtio_scsi_defer_tmf_to_bh(req);
477         ret = -EINPROGRESS;
478         break;
479 
480     case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
481     case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
482     case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
483         if (!d) {
484             goto fail;
485         }
486         if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
487             goto incorrect_lun;
488         }
489 
490         /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
491          * This way, if the bus starts calling back to the notifiers
492          * even before we finish the loop, virtio_scsi_cancel_notify
493          * will not complete the TMF too early.
494          */
495         req->remaining = 1;
496         QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
497             if (r->hba_private) {
498                 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
499                     /* "If there is any command present in the task set, then
500                      * return a service response set to FUNCTION SUCCEEDED".
501                      */
502                     req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
503                     break;
504                 } else {
505                     VirtIOSCSICancelNotifier *notifier;
506 
507                     req->remaining++;
508                     notifier = g_new(VirtIOSCSICancelNotifier, 1);
509                     notifier->notifier.notify = virtio_scsi_cancel_notify;
510                     notifier->tmf_req = req;
511                     scsi_req_cancel_async(r, &notifier->notifier);
512                 }
513             }
514         }
515         if (--req->remaining > 0) {
516             ret = -EINPROGRESS;
517         }
518         break;
519 
520     case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
521     default:
522         req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
523         break;
524     }
525 
526     object_unref(OBJECT(d));
527     return ret;
528 
529 incorrect_lun:
530     req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
531     object_unref(OBJECT(d));
532     return ret;
533 
534 fail:
535     req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
536     object_unref(OBJECT(d));
537     return ret;
538 }
539 
540 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
541 {
542     VirtIODevice *vdev = (VirtIODevice *)s;
543     uint32_t type;
544     int r = 0;
545 
546     if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
547                 &type, sizeof(type)) < sizeof(type)) {
548         virtio_scsi_bad_req(req);
549         return;
550     }
551 
552     virtio_tswap32s(vdev, &type);
553     if (type == VIRTIO_SCSI_T_TMF) {
554         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
555                     sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
556             virtio_scsi_bad_req(req);
557             return;
558         } else {
559             r = virtio_scsi_do_tmf(s, req);
560         }
561 
562     } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
563                type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
564         if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
565                     sizeof(VirtIOSCSICtrlANResp)) < 0) {
566             virtio_scsi_bad_req(req);
567             return;
568         } else {
569             req->req.an.event_requested =
570                 virtio_tswap32(VIRTIO_DEVICE(s), req->req.an.event_requested);
571             trace_virtio_scsi_an_req(virtio_scsi_get_lun(req->req.an.lun),
572                                      req->req.an.event_requested);
573             req->resp.an.event_actual = 0;
574             req->resp.an.response = VIRTIO_SCSI_S_OK;
575         }
576     }
577     if (r == 0) {
578         if (type == VIRTIO_SCSI_T_TMF)
579             trace_virtio_scsi_tmf_resp(virtio_scsi_get_lun(req->req.tmf.lun),
580                                        req->req.tmf.tag,
581                                        req->resp.tmf.response);
582         else if (type == VIRTIO_SCSI_T_AN_QUERY ||
583                  type == VIRTIO_SCSI_T_AN_SUBSCRIBE)
584             trace_virtio_scsi_an_resp(virtio_scsi_get_lun(req->req.an.lun),
585                                       req->resp.an.response);
586         virtio_scsi_complete_req(req);
587     } else {
588         assert(r == -EINPROGRESS);
589     }
590 }
591 
592 static void virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
593 {
594     VirtIOSCSIReq *req;
595 
596     while ((req = virtio_scsi_pop_req(s, vq))) {
597         virtio_scsi_handle_ctrl_req(s, req);
598     }
599 }
600 
601 /*
602  * If dataplane is configured but not yet started, do so now and return true on
603  * success.
604  *
605  * Dataplane is started by the core virtio code but virtqueue handler functions
606  * can also be invoked when a guest kicks before DRIVER_OK, so this helper
607  * function helps us deal with manually starting ioeventfd in that case.
608  */
609 static bool virtio_scsi_defer_to_dataplane(VirtIOSCSI *s)
610 {
611     if (!s->ctx || s->dataplane_started) {
612         return false;
613     }
614 
615     virtio_device_start_ioeventfd(&s->parent_obj.parent_obj);
616     return !s->dataplane_fenced;
617 }
618 
619 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
620 {
621     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
622 
623     if (virtio_scsi_defer_to_dataplane(s)) {
624         return;
625     }
626 
627     virtio_scsi_acquire(s);
628     virtio_scsi_handle_ctrl_vq(s, vq);
629     virtio_scsi_release(s);
630 }
631 
632 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
633 {
634     trace_virtio_scsi_cmd_resp(virtio_scsi_get_lun(req->req.cmd.lun),
635                                req->req.cmd.tag,
636                                req->resp.cmd.response,
637                                req->resp.cmd.status);
638     /* Sense data is not in req->resp and is copied separately
639      * in virtio_scsi_command_complete.
640      */
641     req->resp_size = sizeof(VirtIOSCSICmdResp);
642     virtio_scsi_complete_req(req);
643 }
644 
645 static void virtio_scsi_command_failed(SCSIRequest *r)
646 {
647     VirtIOSCSIReq *req = r->hba_private;
648 
649     if (r->io_canceled) {
650         return;
651     }
652 
653     req->resp.cmd.status = GOOD;
654     switch (r->host_status) {
655     case SCSI_HOST_NO_LUN:
656         req->resp.cmd.response = VIRTIO_SCSI_S_INCORRECT_LUN;
657         break;
658     case SCSI_HOST_BUSY:
659         req->resp.cmd.response = VIRTIO_SCSI_S_BUSY;
660         break;
661     case SCSI_HOST_TIME_OUT:
662     case SCSI_HOST_ABORTED:
663         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
664         break;
665     case SCSI_HOST_BAD_RESPONSE:
666         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
667         break;
668     case SCSI_HOST_RESET:
669         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
670         break;
671     case SCSI_HOST_TRANSPORT_DISRUPTED:
672         req->resp.cmd.response = VIRTIO_SCSI_S_TRANSPORT_FAILURE;
673         break;
674     case SCSI_HOST_TARGET_FAILURE:
675         req->resp.cmd.response = VIRTIO_SCSI_S_TARGET_FAILURE;
676         break;
677     case SCSI_HOST_RESERVATION_ERROR:
678         req->resp.cmd.response = VIRTIO_SCSI_S_NEXUS_FAILURE;
679         break;
680     case SCSI_HOST_ALLOCATION_FAILURE:
681     case SCSI_HOST_MEDIUM_ERROR:
682     case SCSI_HOST_ERROR:
683     default:
684         req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
685         break;
686     }
687     virtio_scsi_complete_cmd_req(req);
688 }
689 
690 static void virtio_scsi_command_complete(SCSIRequest *r, size_t resid)
691 {
692     VirtIOSCSIReq *req = r->hba_private;
693     uint8_t sense[SCSI_SENSE_BUF_SIZE];
694     uint32_t sense_len;
695     VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
696 
697     if (r->io_canceled) {
698         return;
699     }
700 
701     req->resp.cmd.response = VIRTIO_SCSI_S_OK;
702     req->resp.cmd.status = r->status;
703     if (req->resp.cmd.status == GOOD) {
704         req->resp.cmd.resid = virtio_tswap32(vdev, resid);
705     } else {
706         req->resp.cmd.resid = 0;
707         sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
708         sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
709         qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
710                             sense, sense_len);
711         req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
712     }
713     virtio_scsi_complete_cmd_req(req);
714 }
715 
716 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
717                                  uint8_t *buf, size_t buf_len,
718                                  void *hba_private)
719 {
720     VirtIOSCSIReq *req = hba_private;
721 
722     if (cmd->len == 0) {
723         cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
724         memcpy(cmd->buf, buf, cmd->len);
725     }
726 
727     /* Extract the direction and mode directly from the request, for
728      * host device passthrough.
729      */
730     cmd->xfer = req->qsgl.size;
731     cmd->mode = req->mode;
732     return 0;
733 }
734 
735 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
736 {
737     VirtIOSCSIReq *req = r->hba_private;
738 
739     return &req->qsgl;
740 }
741 
742 static void virtio_scsi_request_cancelled(SCSIRequest *r)
743 {
744     VirtIOSCSIReq *req = r->hba_private;
745 
746     if (!req) {
747         return;
748     }
749     if (qatomic_read(&req->dev->resetting)) {
750         req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
751     } else {
752         req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
753     }
754     virtio_scsi_complete_cmd_req(req);
755 }
756 
757 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
758 {
759     req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
760     virtio_scsi_complete_cmd_req(req);
761 }
762 
763 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
764 {
765     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
766     SCSIDevice *d;
767     int rc;
768 
769     rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
770                                sizeof(VirtIOSCSICmdResp) + vs->sense_size);
771     if (rc < 0) {
772         if (rc == -ENOTSUP) {
773             virtio_scsi_fail_cmd_req(req);
774             return -ENOTSUP;
775         } else {
776             virtio_scsi_bad_req(req);
777             return -EINVAL;
778         }
779     }
780     trace_virtio_scsi_cmd_req(virtio_scsi_get_lun(req->req.cmd.lun),
781                               req->req.cmd.tag, req->req.cmd.cdb[0]);
782 
783     d = virtio_scsi_device_get(s, req->req.cmd.lun);
784     if (!d) {
785         req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
786         virtio_scsi_complete_cmd_req(req);
787         return -ENOENT;
788     }
789     virtio_scsi_ctx_check(s, d);
790     req->sreq = scsi_req_new(d, req->req.cmd.tag,
791                              virtio_scsi_get_lun(req->req.cmd.lun),
792                              req->req.cmd.cdb, vs->cdb_size, req);
793 
794     if (req->sreq->cmd.mode != SCSI_XFER_NONE
795         && (req->sreq->cmd.mode != req->mode ||
796             req->sreq->cmd.xfer > req->qsgl.size)) {
797         req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
798         virtio_scsi_complete_cmd_req(req);
799         object_unref(OBJECT(d));
800         return -ENOBUFS;
801     }
802     scsi_req_ref(req->sreq);
803     defer_call_begin();
804     object_unref(OBJECT(d));
805     return 0;
806 }
807 
808 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
809 {
810     SCSIRequest *sreq = req->sreq;
811     if (scsi_req_enqueue(sreq)) {
812         scsi_req_continue(sreq);
813     }
814     defer_call_end();
815     scsi_req_unref(sreq);
816 }
817 
818 static void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
819 {
820     VirtIOSCSIReq *req, *next;
821     int ret = 0;
822     bool suppress_notifications = virtio_queue_get_notification(vq);
823 
824     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
825 
826     do {
827         if (suppress_notifications) {
828             virtio_queue_set_notification(vq, 0);
829         }
830 
831         while ((req = virtio_scsi_pop_req(s, vq))) {
832             ret = virtio_scsi_handle_cmd_req_prepare(s, req);
833             if (!ret) {
834                 QTAILQ_INSERT_TAIL(&reqs, req, next);
835             } else if (ret == -EINVAL) {
836                 /* The device is broken and shouldn't process any request */
837                 while (!QTAILQ_EMPTY(&reqs)) {
838                     req = QTAILQ_FIRST(&reqs);
839                     QTAILQ_REMOVE(&reqs, req, next);
840                     defer_call_end();
841                     scsi_req_unref(req->sreq);
842                     virtqueue_detach_element(req->vq, &req->elem, 0);
843                     virtio_scsi_free_req(req);
844                 }
845             }
846         }
847 
848         if (suppress_notifications) {
849             virtio_queue_set_notification(vq, 1);
850         }
851     } while (ret != -EINVAL && !virtio_queue_empty(vq));
852 
853     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
854         virtio_scsi_handle_cmd_req_submit(s, req);
855     }
856 }
857 
858 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
859 {
860     /* use non-QOM casts in the data path */
861     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
862 
863     if (virtio_scsi_defer_to_dataplane(s)) {
864         return;
865     }
866 
867     virtio_scsi_acquire(s);
868     virtio_scsi_handle_cmd_vq(s, vq);
869     virtio_scsi_release(s);
870 }
871 
872 static void virtio_scsi_get_config(VirtIODevice *vdev,
873                                    uint8_t *config)
874 {
875     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
876     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
877 
878     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
879     virtio_stl_p(vdev, &scsiconf->seg_max,
880                  s->conf.seg_max_adjust ? s->conf.virtqueue_size - 2 : 128 - 2);
881     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
882     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
883     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
884     virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
885     virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
886     virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
887     virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
888     virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
889 }
890 
891 static void virtio_scsi_set_config(VirtIODevice *vdev,
892                                    const uint8_t *config)
893 {
894     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
895     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
896 
897     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
898         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
899         virtio_error(vdev,
900                      "bad data written to virtio-scsi configuration space");
901         return;
902     }
903 
904     vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
905     vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
906 }
907 
908 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
909                                          uint64_t requested_features,
910                                          Error **errp)
911 {
912     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
913 
914     /* Firstly sync all virtio-scsi possible supported features */
915     requested_features |= s->host_features;
916     return requested_features;
917 }
918 
919 static void virtio_scsi_reset(VirtIODevice *vdev)
920 {
921     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
922     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
923 
924     assert(!s->dataplane_started);
925 
926     virtio_scsi_reset_tmf_bh(s);
927 
928     qatomic_inc(&s->resetting);
929     bus_cold_reset(BUS(&s->bus));
930     qatomic_dec(&s->resetting);
931 
932     vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
933     vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
934     s->events_dropped = false;
935 }
936 
937 typedef struct {
938     uint32_t event;
939     uint32_t reason;
940     union {
941         /* Used by messages specific to a device */
942         struct {
943             uint32_t id;
944             uint32_t lun;
945         } address;
946     };
947 } VirtIOSCSIEventInfo;
948 
949 static void virtio_scsi_push_event(VirtIOSCSI *s,
950                                    const VirtIOSCSIEventInfo *info)
951 {
952     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
953     VirtIOSCSIReq *req;
954     VirtIOSCSIEvent *evt;
955     VirtIODevice *vdev = VIRTIO_DEVICE(s);
956     uint32_t event = info->event;
957     uint32_t reason = info->reason;
958 
959     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
960         return;
961     }
962 
963     req = virtio_scsi_pop_req(s, vs->event_vq);
964     if (!req) {
965         s->events_dropped = true;
966         return;
967     }
968 
969     if (s->events_dropped) {
970         event |= VIRTIO_SCSI_T_EVENTS_MISSED;
971         s->events_dropped = false;
972     }
973 
974     if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
975         virtio_scsi_bad_req(req);
976         return;
977     }
978 
979     evt = &req->resp.event;
980     memset(evt, 0, sizeof(VirtIOSCSIEvent));
981     evt->event = virtio_tswap32(vdev, event);
982     evt->reason = virtio_tswap32(vdev, reason);
983     if (event != VIRTIO_SCSI_T_EVENTS_MISSED) {
984         evt->lun[0] = 1;
985         evt->lun[1] = info->address.id;
986 
987         /* Linux wants us to keep the same encoding we use for REPORT LUNS.  */
988         if (info->address.lun >= 256) {
989             evt->lun[2] = (info->address.lun >> 8) | 0x40;
990         }
991         evt->lun[3] = info->address.lun & 0xFF;
992     }
993     trace_virtio_scsi_event(virtio_scsi_get_lun(evt->lun), event, reason);
994 
995     virtio_scsi_complete_req(req);
996 }
997 
998 static void virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
999 {
1000     if (s->events_dropped) {
1001         VirtIOSCSIEventInfo info = {
1002             .event = VIRTIO_SCSI_T_NO_EVENT,
1003         };
1004         virtio_scsi_push_event(s, &info);
1005     }
1006 }
1007 
1008 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
1009 {
1010     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
1011 
1012     if (virtio_scsi_defer_to_dataplane(s)) {
1013         return;
1014     }
1015 
1016     virtio_scsi_acquire(s);
1017     virtio_scsi_handle_event_vq(s, vq);
1018     virtio_scsi_release(s);
1019 }
1020 
1021 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
1022 {
1023     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
1024     VirtIODevice *vdev = VIRTIO_DEVICE(s);
1025 
1026     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
1027         dev->type != TYPE_ROM) {
1028         VirtIOSCSIEventInfo info = {
1029             .event   = VIRTIO_SCSI_T_PARAM_CHANGE,
1030             .reason  = sense.asc | (sense.ascq << 8),
1031             .address = {
1032                 .id  = dev->id,
1033                 .lun = dev->lun,
1034             },
1035         };
1036 
1037         virtio_scsi_acquire(s);
1038         virtio_scsi_push_event(s, &info);
1039         virtio_scsi_release(s);
1040     }
1041 }
1042 
1043 static void virtio_scsi_pre_hotplug(HotplugHandler *hotplug_dev,
1044                                     DeviceState *dev, Error **errp)
1045 {
1046     SCSIDevice *sd = SCSI_DEVICE(dev);
1047     sd->hba_supports_iothread = true;
1048 }
1049 
1050 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
1051                                 Error **errp)
1052 {
1053     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
1054     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
1055     SCSIDevice *sd = SCSI_DEVICE(dev);
1056     AioContext *old_context;
1057     int ret;
1058 
1059     if (s->ctx && !s->dataplane_fenced) {
1060         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
1061             return;
1062         }
1063         old_context = blk_get_aio_context(sd->conf.blk);
1064         aio_context_acquire(old_context);
1065         ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
1066         aio_context_release(old_context);
1067         if (ret < 0) {
1068             return;
1069         }
1070     }
1071 
1072     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
1073         VirtIOSCSIEventInfo info = {
1074             .event   = VIRTIO_SCSI_T_TRANSPORT_RESET,
1075             .reason  = VIRTIO_SCSI_EVT_RESET_RESCAN,
1076             .address = {
1077                 .id  = sd->id,
1078                 .lun = sd->lun,
1079             },
1080         };
1081 
1082         virtio_scsi_acquire(s);
1083         virtio_scsi_push_event(s, &info);
1084         scsi_bus_set_ua(&s->bus, SENSE_CODE(REPORTED_LUNS_CHANGED));
1085         virtio_scsi_release(s);
1086     }
1087 }
1088 
1089 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
1090                                   Error **errp)
1091 {
1092     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
1093     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
1094     SCSIDevice *sd = SCSI_DEVICE(dev);
1095     VirtIOSCSIEventInfo info = {
1096         .event   = VIRTIO_SCSI_T_TRANSPORT_RESET,
1097         .reason  = VIRTIO_SCSI_EVT_RESET_REMOVED,
1098         .address = {
1099             .id  = sd->id,
1100             .lun = sd->lun,
1101         },
1102     };
1103 
1104     qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
1105 
1106     if (s->ctx) {
1107         virtio_scsi_acquire(s);
1108         /* If other users keep the BlockBackend in the iothread, that's ok */
1109         blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL);
1110         virtio_scsi_release(s);
1111     }
1112 
1113     if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
1114         virtio_scsi_acquire(s);
1115         virtio_scsi_push_event(s, &info);
1116         scsi_bus_set_ua(&s->bus, SENSE_CODE(REPORTED_LUNS_CHANGED));
1117         virtio_scsi_release(s);
1118     }
1119 }
1120 
1121 /* Suspend virtqueue ioeventfd processing during drain */
1122 static void virtio_scsi_drained_begin(SCSIBus *bus)
1123 {
1124     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
1125     VirtIODevice *vdev = VIRTIO_DEVICE(s);
1126     uint32_t total_queues = VIRTIO_SCSI_VQ_NUM_FIXED +
1127                             s->parent_obj.conf.num_queues;
1128 
1129     /*
1130      * Drain is called when stopping dataplane but the host notifier has
1131      * already been detached. Detaching multiple times is a no-op if nothing
1132      * else is using the monitoring same file descriptor, but avoid it just in
1133      * case.
1134      *
1135      * Also, don't detach if dataplane has not even been started yet because
1136      * the host notifier isn't attached.
1137      */
1138     if (s->dataplane_stopping || !s->dataplane_started) {
1139         return;
1140     }
1141 
1142     for (uint32_t i = 0; i < total_queues; i++) {
1143         VirtQueue *vq = virtio_get_queue(vdev, i);
1144         virtio_queue_aio_detach_host_notifier(vq, s->ctx);
1145     }
1146 }
1147 
1148 /* Resume virtqueue ioeventfd processing after drain */
1149 static void virtio_scsi_drained_end(SCSIBus *bus)
1150 {
1151     VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
1152     VirtIODevice *vdev = VIRTIO_DEVICE(s);
1153     uint32_t total_queues = VIRTIO_SCSI_VQ_NUM_FIXED +
1154                             s->parent_obj.conf.num_queues;
1155 
1156     /*
1157      * Drain is called when stopping dataplane. Keep the host notifier detached
1158      * so it's not left dangling after dataplane is stopped.
1159      *
1160      * Also, don't attach if dataplane has not even been started yet. We're not
1161      * ready.
1162      */
1163     if (s->dataplane_stopping || !s->dataplane_started) {
1164         return;
1165     }
1166 
1167     for (uint32_t i = 0; i < total_queues; i++) {
1168         VirtQueue *vq = virtio_get_queue(vdev, i);
1169         virtio_queue_aio_attach_host_notifier(vq, s->ctx);
1170     }
1171 }
1172 
1173 static struct SCSIBusInfo virtio_scsi_scsi_info = {
1174     .tcq = true,
1175     .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
1176     .max_target = VIRTIO_SCSI_MAX_TARGET,
1177     .max_lun = VIRTIO_SCSI_MAX_LUN,
1178 
1179     .complete = virtio_scsi_command_complete,
1180     .fail = virtio_scsi_command_failed,
1181     .cancel = virtio_scsi_request_cancelled,
1182     .change = virtio_scsi_change,
1183     .parse_cdb = virtio_scsi_parse_cdb,
1184     .get_sg_list = virtio_scsi_get_sg_list,
1185     .save_request = virtio_scsi_save_request,
1186     .load_request = virtio_scsi_load_request,
1187     .drained_begin = virtio_scsi_drained_begin,
1188     .drained_end = virtio_scsi_drained_end,
1189 };
1190 
1191 void virtio_scsi_common_realize(DeviceState *dev,
1192                                 VirtIOHandleOutput ctrl,
1193                                 VirtIOHandleOutput evt,
1194                                 VirtIOHandleOutput cmd,
1195                                 Error **errp)
1196 {
1197     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1198     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
1199     int i;
1200 
1201     virtio_init(vdev, VIRTIO_ID_SCSI, sizeof(VirtIOSCSIConfig));
1202 
1203     if (s->conf.num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) {
1204         s->conf.num_queues = 1;
1205     }
1206     if (s->conf.num_queues == 0 ||
1207             s->conf.num_queues > VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED) {
1208         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
1209                          "must be a positive integer less than %d.",
1210                    s->conf.num_queues,
1211                    VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED);
1212         virtio_cleanup(vdev);
1213         return;
1214     }
1215     if (s->conf.virtqueue_size <= 2) {
1216         error_setg(errp, "invalid virtqueue_size property (= %" PRIu32 "), "
1217                    "must be > 2", s->conf.virtqueue_size);
1218         return;
1219     }
1220     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
1221     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
1222     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
1223 
1224     s->ctrl_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, ctrl);
1225     s->event_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, evt);
1226     for (i = 0; i < s->conf.num_queues; i++) {
1227         s->cmd_vqs[i] = virtio_add_queue(vdev, s->conf.virtqueue_size, cmd);
1228     }
1229 }
1230 
1231 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
1232 {
1233     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1234     VirtIOSCSI *s = VIRTIO_SCSI(dev);
1235     Error *err = NULL;
1236 
1237     QTAILQ_INIT(&s->tmf_bh_list);
1238 
1239     virtio_scsi_common_realize(dev,
1240                                virtio_scsi_handle_ctrl,
1241                                virtio_scsi_handle_event,
1242                                virtio_scsi_handle_cmd,
1243                                &err);
1244     if (err != NULL) {
1245         error_propagate(errp, err);
1246         return;
1247     }
1248 
1249     scsi_bus_init_named(&s->bus, sizeof(s->bus), dev,
1250                        &virtio_scsi_scsi_info, vdev->bus_name);
1251     /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
1252     qbus_set_hotplug_handler(BUS(&s->bus), OBJECT(dev));
1253 
1254     virtio_scsi_dataplane_setup(s, errp);
1255 }
1256 
1257 void virtio_scsi_common_unrealize(DeviceState *dev)
1258 {
1259     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1260     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
1261     int i;
1262 
1263     virtio_delete_queue(vs->ctrl_vq);
1264     virtio_delete_queue(vs->event_vq);
1265     for (i = 0; i < vs->conf.num_queues; i++) {
1266         virtio_delete_queue(vs->cmd_vqs[i]);
1267     }
1268     g_free(vs->cmd_vqs);
1269     virtio_cleanup(vdev);
1270 }
1271 
1272 static void virtio_scsi_device_unrealize(DeviceState *dev)
1273 {
1274     VirtIOSCSI *s = VIRTIO_SCSI(dev);
1275 
1276     virtio_scsi_reset_tmf_bh(s);
1277 
1278     qbus_set_hotplug_handler(BUS(&s->bus), NULL);
1279     virtio_scsi_common_unrealize(dev);
1280 }
1281 
1282 static Property virtio_scsi_properties[] = {
1283     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues,
1284                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
1285     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
1286                                          parent_obj.conf.virtqueue_size, 256),
1287     DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI,
1288                       parent_obj.conf.seg_max_adjust, true),
1289     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
1290                                                   0xFFFF),
1291     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
1292                                                   128),
1293     DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
1294                                            VIRTIO_SCSI_F_HOTPLUG, true),
1295     DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
1296                                                 VIRTIO_SCSI_F_CHANGE, true),
1297     DEFINE_PROP_LINK("iothread", VirtIOSCSI, parent_obj.conf.iothread,
1298                      TYPE_IOTHREAD, IOThread *),
1299     DEFINE_PROP_END_OF_LIST(),
1300 };
1301 
1302 static const VMStateDescription vmstate_virtio_scsi = {
1303     .name = "virtio-scsi",
1304     .minimum_version_id = 1,
1305     .version_id = 1,
1306     .fields = (VMStateField[]) {
1307         VMSTATE_VIRTIO_DEVICE,
1308         VMSTATE_END_OF_LIST()
1309     },
1310 };
1311 
1312 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
1313 {
1314     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1315     DeviceClass *dc = DEVICE_CLASS(klass);
1316 
1317     vdc->get_config = virtio_scsi_get_config;
1318     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1319 }
1320 
1321 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
1322 {
1323     DeviceClass *dc = DEVICE_CLASS(klass);
1324     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1325     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1326 
1327     device_class_set_props(dc, virtio_scsi_properties);
1328     dc->vmsd = &vmstate_virtio_scsi;
1329     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1330     vdc->realize = virtio_scsi_device_realize;
1331     vdc->unrealize = virtio_scsi_device_unrealize;
1332     vdc->set_config = virtio_scsi_set_config;
1333     vdc->get_features = virtio_scsi_get_features;
1334     vdc->reset = virtio_scsi_reset;
1335     vdc->start_ioeventfd = virtio_scsi_dataplane_start;
1336     vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
1337     hc->pre_plug = virtio_scsi_pre_hotplug;
1338     hc->plug = virtio_scsi_hotplug;
1339     hc->unplug = virtio_scsi_hotunplug;
1340 }
1341 
1342 static const TypeInfo virtio_scsi_common_info = {
1343     .name = TYPE_VIRTIO_SCSI_COMMON,
1344     .parent = TYPE_VIRTIO_DEVICE,
1345     .instance_size = sizeof(VirtIOSCSICommon),
1346     .abstract = true,
1347     .class_init = virtio_scsi_common_class_init,
1348 };
1349 
1350 static const TypeInfo virtio_scsi_info = {
1351     .name = TYPE_VIRTIO_SCSI,
1352     .parent = TYPE_VIRTIO_SCSI_COMMON,
1353     .instance_size = sizeof(VirtIOSCSI),
1354     .class_init = virtio_scsi_class_init,
1355     .interfaces = (InterfaceInfo[]) {
1356         { TYPE_HOTPLUG_HANDLER },
1357         { }
1358     }
1359 };
1360 
1361 static void virtio_register_types(void)
1362 {
1363     type_register_static(&virtio_scsi_common_info);
1364     type_register_static(&virtio_scsi_info);
1365 }
1366 
1367 type_init(virtio_register_types)
1368