device-core: use RCU for list of children of a bus
[qemu.git] / hw / scsi / virtio-scsi.c
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/error-report.h"
22 #include "qemu/iov.h"
23 #include "qemu/module.h"
24 #include "sysemu/block-backend.h"
25 #include "hw/qdev-properties.h"
26 #include "hw/scsi/scsi.h"
27 #include "scsi/constants.h"
28 #include "hw/virtio/virtio-bus.h"
29 #include "hw/virtio/virtio-access.h"
30
31 static inline int virtio_scsi_get_lun(uint8_t *lun)
32 {
33 return ((lun[2] << 8) | lun[3]) & 0x3FFF;
34 }
35
36 static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
37 {
38 if (lun[0] != 1) {
39 return NULL;
40 }
41 if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
42 return NULL;
43 }
44 return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
45 }
46
47 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
48 {
49 VirtIODevice *vdev = VIRTIO_DEVICE(s);
50 const size_t zero_skip =
51 offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
52
53 req->vq = vq;
54 req->dev = s;
55 qemu_sglist_init(&req->qsgl, DEVICE(s), 8, vdev->dma_as);
56 qemu_iovec_init(&req->resp_iov, 1);
57 memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
58 }
59
60 void virtio_scsi_free_req(VirtIOSCSIReq *req)
61 {
62 qemu_iovec_destroy(&req->resp_iov);
63 qemu_sglist_destroy(&req->qsgl);
64 g_free(req);
65 }
66
67 static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
68 {
69 VirtIOSCSI *s = req->dev;
70 VirtQueue *vq = req->vq;
71 VirtIODevice *vdev = VIRTIO_DEVICE(s);
72
73 qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
74 virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
75 if (s->dataplane_started && !s->dataplane_fenced) {
76 virtio_notify_irqfd(vdev, vq);
77 } else {
78 virtio_notify(vdev, vq);
79 }
80
81 if (req->sreq) {
82 req->sreq->hba_private = NULL;
83 scsi_req_unref(req->sreq);
84 }
85 virtio_scsi_free_req(req);
86 }
87
88 static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
89 {
90 virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
91 virtqueue_detach_element(req->vq, &req->elem, 0);
92 virtio_scsi_free_req(req);
93 }
94
95 static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
96 hwaddr *addr, int num, size_t skip)
97 {
98 QEMUSGList *qsgl = &req->qsgl;
99 size_t copied = 0;
100
101 while (num) {
102 if (skip >= iov->iov_len) {
103 skip -= iov->iov_len;
104 } else {
105 qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
106 copied += iov->iov_len - skip;
107 skip = 0;
108 }
109 iov++;
110 addr++;
111 num--;
112 }
113
114 assert(skip == 0);
115 return copied;
116 }
117
118 static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
119 unsigned req_size, unsigned resp_size)
120 {
121 VirtIODevice *vdev = (VirtIODevice *) req->dev;
122 size_t in_size, out_size;
123
124 if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
125 &req->req, req_size) < req_size) {
126 return -EINVAL;
127 }
128
129 if (qemu_iovec_concat_iov(&req->resp_iov,
130 req->elem.in_sg, req->elem.in_num, 0,
131 resp_size) < resp_size) {
132 return -EINVAL;
133 }
134
135 req->resp_size = resp_size;
136
137 /* Old BIOSes left some padding by mistake after the req_size/resp_size.
138 * As a workaround, always consider the first buffer as the virtio-scsi
139 * request/response, making the payload start at the second element
140 * of the iovec.
141 *
142 * The actual length of the response header, stored in req->resp_size,
143 * does not change.
144 *
145 * TODO: always disable this workaround for virtio 1.0 devices.
146 */
147 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
148 if (req->elem.out_num) {
149 req_size = req->elem.out_sg[0].iov_len;
150 }
151 if (req->elem.in_num) {
152 resp_size = req->elem.in_sg[0].iov_len;
153 }
154 }
155
156 out_size = qemu_sgl_concat(req, req->elem.out_sg,
157 &req->elem.out_addr[0], req->elem.out_num,
158 req_size);
159 in_size = qemu_sgl_concat(req, req->elem.in_sg,
160 &req->elem.in_addr[0], req->elem.in_num,
161 resp_size);
162
163 if (out_size && in_size) {
164 return -ENOTSUP;
165 }
166
167 if (out_size) {
168 req->mode = SCSI_XFER_TO_DEV;
169 } else if (in_size) {
170 req->mode = SCSI_XFER_FROM_DEV;
171 }
172
173 return 0;
174 }
175
176 static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
177 {
178 VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
179 VirtIOSCSIReq *req;
180
181 req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
182 if (!req) {
183 return NULL;
184 }
185 virtio_scsi_init_req(s, vq, req);
186 return req;
187 }
188
189 static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
190 {
191 VirtIOSCSIReq *req = sreq->hba_private;
192 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
193 VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
194 uint32_t n = virtio_get_queue_index(req->vq) - VIRTIO_SCSI_VQ_NUM_FIXED;
195
196 assert(n < vs->conf.num_queues);
197 qemu_put_be32s(f, &n);
198 qemu_put_virtqueue_element(vdev, f, &req->elem);
199 }
200
201 static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
202 {
203 SCSIBus *bus = sreq->bus;
204 VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
205 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
206 VirtIODevice *vdev = VIRTIO_DEVICE(s);
207 VirtIOSCSIReq *req;
208 uint32_t n;
209
210 qemu_get_be32s(f, &n);
211 assert(n < vs->conf.num_queues);
212 req = qemu_get_virtqueue_element(vdev, f,
213 sizeof(VirtIOSCSIReq) + vs->cdb_size);
214 virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
215
216 if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
217 sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
218 error_report("invalid SCSI request migration data");
219 exit(1);
220 }
221
222 scsi_req_ref(sreq);
223 req->sreq = sreq;
224 if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
225 assert(req->sreq->cmd.mode == req->mode);
226 }
227 return req;
228 }
229
230 typedef struct {
231 Notifier notifier;
232 VirtIOSCSIReq *tmf_req;
233 } VirtIOSCSICancelNotifier;
234
235 static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
236 {
237 VirtIOSCSICancelNotifier *n = container_of(notifier,
238 VirtIOSCSICancelNotifier,
239 notifier);
240
241 if (--n->tmf_req->remaining == 0) {
242 virtio_scsi_complete_req(n->tmf_req);
243 }
244 g_free(n);
245 }
246
247 static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
248 {
249 if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
250 assert(blk_get_aio_context(d->conf.blk) == s->ctx);
251 }
252 }
253
254 /* Return 0 if the request is ready to be completed and return to guest;
255 * -EINPROGRESS if the request is submitted and will be completed later, in the
256 * case of async cancellation. */
257 static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
258 {
259 SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
260 SCSIRequest *r, *next;
261 BusChild *kid;
262 int target;
263 int ret = 0;
264
265 virtio_scsi_ctx_check(s, d);
266 /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE". */
267 req->resp.tmf.response = VIRTIO_SCSI_S_OK;
268
269 /*
270 * req->req.tmf has the QEMU_PACKED attribute. Don't use virtio_tswap32s()
271 * to avoid compiler errors.
272 */
273 req->req.tmf.subtype =
274 virtio_tswap32(VIRTIO_DEVICE(s), req->req.tmf.subtype);
275
276 switch (req->req.tmf.subtype) {
277 case VIRTIO_SCSI_T_TMF_ABORT_TASK:
278 case VIRTIO_SCSI_T_TMF_QUERY_TASK:
279 if (!d) {
280 goto fail;
281 }
282 if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
283 goto incorrect_lun;
284 }
285 QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
286 VirtIOSCSIReq *cmd_req = r->hba_private;
287 if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
288 break;
289 }
290 }
291 if (r) {
292 /*
293 * Assert that the request has not been completed yet, we
294 * check for it in the loop above.
295 */
296 assert(r->hba_private);
297 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
298 /* "If the specified command is present in the task set, then
299 * return a service response set to FUNCTION SUCCEEDED".
300 */
301 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
302 } else {
303 VirtIOSCSICancelNotifier *notifier;
304
305 req->remaining = 1;
306 notifier = g_new(VirtIOSCSICancelNotifier, 1);
307 notifier->tmf_req = req;
308 notifier->notifier.notify = virtio_scsi_cancel_notify;
309 scsi_req_cancel_async(r, &notifier->notifier);
310 ret = -EINPROGRESS;
311 }
312 }
313 break;
314
315 case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
316 if (!d) {
317 goto fail;
318 }
319 if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
320 goto incorrect_lun;
321 }
322 s->resetting++;
323 qdev_reset_all(&d->qdev);
324 s->resetting--;
325 break;
326
327 case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
328 case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
329 case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
330 if (!d) {
331 goto fail;
332 }
333 if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
334 goto incorrect_lun;
335 }
336
337 /* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
338 * This way, if the bus starts calling back to the notifiers
339 * even before we finish the loop, virtio_scsi_cancel_notify
340 * will not complete the TMF too early.
341 */
342 req->remaining = 1;
343 QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
344 if (r->hba_private) {
345 if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
346 /* "If there is any command present in the task set, then
347 * return a service response set to FUNCTION SUCCEEDED".
348 */
349 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
350 break;
351 } else {
352 VirtIOSCSICancelNotifier *notifier;
353
354 req->remaining++;
355 notifier = g_new(VirtIOSCSICancelNotifier, 1);
356 notifier->notifier.notify = virtio_scsi_cancel_notify;
357 notifier->tmf_req = req;
358 scsi_req_cancel_async(r, &notifier->notifier);
359 }
360 }
361 }
362 if (--req->remaining > 0) {
363 ret = -EINPROGRESS;
364 }
365 break;
366
367 case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
368 target = req->req.tmf.lun[1];
369 s->resetting++;
370
371 rcu_read_lock();
372 QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) {
373 d = SCSI_DEVICE(kid->child);
374 if (d->channel == 0 && d->id == target) {
375 qdev_reset_all(&d->qdev);
376 }
377 }
378 rcu_read_unlock();
379
380 s->resetting--;
381 break;
382
383 case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
384 default:
385 req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
386 break;
387 }
388
389 return ret;
390
391 incorrect_lun:
392 req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
393 return ret;
394
395 fail:
396 req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
397 return ret;
398 }
399
400 static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
401 {
402 VirtIODevice *vdev = (VirtIODevice *)s;
403 uint32_t type;
404 int r = 0;
405
406 if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
407 &type, sizeof(type)) < sizeof(type)) {
408 virtio_scsi_bad_req(req);
409 return;
410 }
411
412 virtio_tswap32s(vdev, &type);
413 if (type == VIRTIO_SCSI_T_TMF) {
414 if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
415 sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
416 virtio_scsi_bad_req(req);
417 return;
418 } else {
419 r = virtio_scsi_do_tmf(s, req);
420 }
421
422 } else if (type == VIRTIO_SCSI_T_AN_QUERY ||
423 type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
424 if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
425 sizeof(VirtIOSCSICtrlANResp)) < 0) {
426 virtio_scsi_bad_req(req);
427 return;
428 } else {
429 req->resp.an.event_actual = 0;
430 req->resp.an.response = VIRTIO_SCSI_S_OK;
431 }
432 }
433 if (r == 0) {
434 virtio_scsi_complete_req(req);
435 } else {
436 assert(r == -EINPROGRESS);
437 }
438 }
439
440 bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
441 {
442 VirtIOSCSIReq *req;
443 bool progress = false;
444
445 while ((req = virtio_scsi_pop_req(s, vq))) {
446 progress = true;
447 virtio_scsi_handle_ctrl_req(s, req);
448 }
449 return progress;
450 }
451
452 static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
453 {
454 VirtIOSCSI *s = (VirtIOSCSI *)vdev;
455
456 if (s->ctx) {
457 virtio_device_start_ioeventfd(vdev);
458 if (!s->dataplane_fenced) {
459 return;
460 }
461 }
462 virtio_scsi_acquire(s);
463 virtio_scsi_handle_ctrl_vq(s, vq);
464 virtio_scsi_release(s);
465 }
466
467 static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
468 {
469 /* Sense data is not in req->resp and is copied separately
470 * in virtio_scsi_command_complete.
471 */
472 req->resp_size = sizeof(VirtIOSCSICmdResp);
473 virtio_scsi_complete_req(req);
474 }
475
476 static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
477 size_t resid)
478 {
479 VirtIOSCSIReq *req = r->hba_private;
480 uint8_t sense[SCSI_SENSE_BUF_SIZE];
481 uint32_t sense_len;
482 VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
483
484 if (r->io_canceled) {
485 return;
486 }
487
488 req->resp.cmd.response = VIRTIO_SCSI_S_OK;
489 req->resp.cmd.status = status;
490 if (req->resp.cmd.status == GOOD) {
491 req->resp.cmd.resid = virtio_tswap32(vdev, resid);
492 } else {
493 req->resp.cmd.resid = 0;
494 sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
495 sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
496 qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
497 sense, sense_len);
498 req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
499 }
500 virtio_scsi_complete_cmd_req(req);
501 }
502
503 static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
504 uint8_t *buf, void *hba_private)
505 {
506 VirtIOSCSIReq *req = hba_private;
507
508 if (cmd->len == 0) {
509 cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
510 memcpy(cmd->buf, buf, cmd->len);
511 }
512
513 /* Extract the direction and mode directly from the request, for
514 * host device passthrough.
515 */
516 cmd->xfer = req->qsgl.size;
517 cmd->mode = req->mode;
518 return 0;
519 }
520
521 static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
522 {
523 VirtIOSCSIReq *req = r->hba_private;
524
525 return &req->qsgl;
526 }
527
528 static void virtio_scsi_request_cancelled(SCSIRequest *r)
529 {
530 VirtIOSCSIReq *req = r->hba_private;
531
532 if (!req) {
533 return;
534 }
535 if (req->dev->resetting) {
536 req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
537 } else {
538 req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
539 }
540 virtio_scsi_complete_cmd_req(req);
541 }
542
543 static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
544 {
545 req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
546 virtio_scsi_complete_cmd_req(req);
547 }
548
549 static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
550 {
551 VirtIOSCSICommon *vs = &s->parent_obj;
552 SCSIDevice *d;
553 int rc;
554
555 rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
556 sizeof(VirtIOSCSICmdResp) + vs->sense_size);
557 if (rc < 0) {
558 if (rc == -ENOTSUP) {
559 virtio_scsi_fail_cmd_req(req);
560 return -ENOTSUP;
561 } else {
562 virtio_scsi_bad_req(req);
563 return -EINVAL;
564 }
565 }
566
567 d = virtio_scsi_device_find(s, req->req.cmd.lun);
568 if (!d) {
569 req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
570 virtio_scsi_complete_cmd_req(req);
571 return -ENOENT;
572 }
573 virtio_scsi_ctx_check(s, d);
574 req->sreq = scsi_req_new(d, req->req.cmd.tag,
575 virtio_scsi_get_lun(req->req.cmd.lun),
576 req->req.cmd.cdb, req);
577
578 if (req->sreq->cmd.mode != SCSI_XFER_NONE
579 && (req->sreq->cmd.mode != req->mode ||
580 req->sreq->cmd.xfer > req->qsgl.size)) {
581 req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
582 virtio_scsi_complete_cmd_req(req);
583 return -ENOBUFS;
584 }
585 scsi_req_ref(req->sreq);
586 blk_io_plug(d->conf.blk);
587 return 0;
588 }
589
590 static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
591 {
592 SCSIRequest *sreq = req->sreq;
593 if (scsi_req_enqueue(sreq)) {
594 scsi_req_continue(sreq);
595 }
596 blk_io_unplug(sreq->dev->conf.blk);
597 scsi_req_unref(sreq);
598 }
599
600 bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
601 {
602 VirtIOSCSIReq *req, *next;
603 int ret = 0;
604 bool suppress_notifications = virtio_queue_get_notification(vq);
605 bool progress = false;
606
607 QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
608
609 do {
610 if (suppress_notifications) {
611 virtio_queue_set_notification(vq, 0);
612 }
613
614 while ((req = virtio_scsi_pop_req(s, vq))) {
615 progress = true;
616 ret = virtio_scsi_handle_cmd_req_prepare(s, req);
617 if (!ret) {
618 QTAILQ_INSERT_TAIL(&reqs, req, next);
619 } else if (ret == -EINVAL) {
620 /* The device is broken and shouldn't process any request */
621 while (!QTAILQ_EMPTY(&reqs)) {
622 req = QTAILQ_FIRST(&reqs);
623 QTAILQ_REMOVE(&reqs, req, next);
624 blk_io_unplug(req->sreq->dev->conf.blk);
625 scsi_req_unref(req->sreq);
626 virtqueue_detach_element(req->vq, &req->elem, 0);
627 virtio_scsi_free_req(req);
628 }
629 }
630 }
631
632 if (suppress_notifications) {
633 virtio_queue_set_notification(vq, 1);
634 }
635 } while (ret != -EINVAL && !virtio_queue_empty(vq));
636
637 QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
638 virtio_scsi_handle_cmd_req_submit(s, req);
639 }
640 return progress;
641 }
642
643 static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
644 {
645 /* use non-QOM casts in the data path */
646 VirtIOSCSI *s = (VirtIOSCSI *)vdev;
647
648 if (s->ctx) {
649 virtio_device_start_ioeventfd(vdev);
650 if (!s->dataplane_fenced) {
651 return;
652 }
653 }
654 virtio_scsi_acquire(s);
655 virtio_scsi_handle_cmd_vq(s, vq);
656 virtio_scsi_release(s);
657 }
658
659 static void virtio_scsi_get_config(VirtIODevice *vdev,
660 uint8_t *config)
661 {
662 VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
663 VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
664
665 virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
666 virtio_stl_p(vdev, &scsiconf->seg_max,
667 s->conf.seg_max_adjust ? s->conf.virtqueue_size - 2 : 128 - 2);
668 virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
669 virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
670 virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
671 virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
672 virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
673 virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
674 virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
675 virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
676 }
677
678 static void virtio_scsi_set_config(VirtIODevice *vdev,
679 const uint8_t *config)
680 {
681 VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
682 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
683
684 if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) >= 65536 ||
685 (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
686 virtio_error(vdev,
687 "bad data written to virtio-scsi configuration space");
688 return;
689 }
690
691 vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
692 vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
693 }
694
695 static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
696 uint64_t requested_features,
697 Error **errp)
698 {
699 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
700
701 /* Firstly sync all virtio-scsi possible supported features */
702 requested_features |= s->host_features;
703 return requested_features;
704 }
705
706 static void virtio_scsi_reset(VirtIODevice *vdev)
707 {
708 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
709 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
710
711 assert(!s->dataplane_started);
712 s->resetting++;
713 qbus_reset_all(BUS(&s->bus));
714 s->resetting--;
715
716 vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
717 vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
718 s->events_dropped = false;
719 }
720
721 void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
722 uint32_t event, uint32_t reason)
723 {
724 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
725 VirtIOSCSIReq *req;
726 VirtIOSCSIEvent *evt;
727 VirtIODevice *vdev = VIRTIO_DEVICE(s);
728
729 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
730 return;
731 }
732
733 req = virtio_scsi_pop_req(s, vs->event_vq);
734 if (!req) {
735 s->events_dropped = true;
736 return;
737 }
738
739 if (s->events_dropped) {
740 event |= VIRTIO_SCSI_T_EVENTS_MISSED;
741 s->events_dropped = false;
742 }
743
744 if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
745 virtio_scsi_bad_req(req);
746 return;
747 }
748
749 evt = &req->resp.event;
750 memset(evt, 0, sizeof(VirtIOSCSIEvent));
751 evt->event = virtio_tswap32(vdev, event);
752 evt->reason = virtio_tswap32(vdev, reason);
753 if (!dev) {
754 assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
755 } else {
756 evt->lun[0] = 1;
757 evt->lun[1] = dev->id;
758
759 /* Linux wants us to keep the same encoding we use for REPORT LUNS. */
760 if (dev->lun >= 256) {
761 evt->lun[2] = (dev->lun >> 8) | 0x40;
762 }
763 evt->lun[3] = dev->lun & 0xFF;
764 }
765 virtio_scsi_complete_req(req);
766 }
767
768 bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
769 {
770 if (s->events_dropped) {
771 virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
772 return true;
773 }
774 return false;
775 }
776
777 static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
778 {
779 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
780
781 if (s->ctx) {
782 virtio_device_start_ioeventfd(vdev);
783 if (!s->dataplane_fenced) {
784 return;
785 }
786 }
787 virtio_scsi_acquire(s);
788 virtio_scsi_handle_event_vq(s, vq);
789 virtio_scsi_release(s);
790 }
791
792 static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
793 {
794 VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
795 VirtIODevice *vdev = VIRTIO_DEVICE(s);
796
797 if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
798 dev->type != TYPE_ROM) {
799 virtio_scsi_acquire(s);
800 virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
801 sense.asc | (sense.ascq << 8));
802 virtio_scsi_release(s);
803 }
804 }
805
806 static void virtio_scsi_pre_hotplug(HotplugHandler *hotplug_dev,
807 DeviceState *dev, Error **errp)
808 {
809 SCSIDevice *sd = SCSI_DEVICE(dev);
810 sd->hba_supports_iothread = true;
811 }
812
813 static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
814 Error **errp)
815 {
816 VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
817 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
818 SCSIDevice *sd = SCSI_DEVICE(dev);
819 int ret;
820
821 if (s->ctx && !s->dataplane_fenced) {
822 if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
823 return;
824 }
825 virtio_scsi_acquire(s);
826 ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
827 virtio_scsi_release(s);
828 if (ret < 0) {
829 return;
830 }
831 }
832
833 if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
834 virtio_scsi_acquire(s);
835 virtio_scsi_push_event(s, sd,
836 VIRTIO_SCSI_T_TRANSPORT_RESET,
837 VIRTIO_SCSI_EVT_RESET_RESCAN);
838 virtio_scsi_release(s);
839 }
840 }
841
842 static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
843 Error **errp)
844 {
845 VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
846 VirtIOSCSI *s = VIRTIO_SCSI(vdev);
847 SCSIDevice *sd = SCSI_DEVICE(dev);
848 AioContext *ctx = s->ctx ?: qemu_get_aio_context();
849
850 if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
851 virtio_scsi_acquire(s);
852 virtio_scsi_push_event(s, sd,
853 VIRTIO_SCSI_T_TRANSPORT_RESET,
854 VIRTIO_SCSI_EVT_RESET_REMOVED);
855 virtio_scsi_release(s);
856 }
857
858 aio_disable_external(ctx);
859 qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
860 aio_enable_external(ctx);
861
862 if (s->ctx) {
863 virtio_scsi_acquire(s);
864 /* If other users keep the BlockBackend in the iothread, that's ok */
865 blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL);
866 virtio_scsi_release(s);
867 }
868 }
869
870 static struct SCSIBusInfo virtio_scsi_scsi_info = {
871 .tcq = true,
872 .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
873 .max_target = VIRTIO_SCSI_MAX_TARGET,
874 .max_lun = VIRTIO_SCSI_MAX_LUN,
875
876 .complete = virtio_scsi_command_complete,
877 .cancel = virtio_scsi_request_cancelled,
878 .change = virtio_scsi_change,
879 .parse_cdb = virtio_scsi_parse_cdb,
880 .get_sg_list = virtio_scsi_get_sg_list,
881 .save_request = virtio_scsi_save_request,
882 .load_request = virtio_scsi_load_request,
883 };
884
885 void virtio_scsi_common_realize(DeviceState *dev,
886 VirtIOHandleOutput ctrl,
887 VirtIOHandleOutput evt,
888 VirtIOHandleOutput cmd,
889 Error **errp)
890 {
891 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
892 VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
893 int i;
894
895 virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
896 sizeof(VirtIOSCSIConfig));
897
898 if (s->conf.num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) {
899 s->conf.num_queues = 1;
900 }
901 if (s->conf.num_queues == 0 ||
902 s->conf.num_queues > VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED) {
903 error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
904 "must be a positive integer less than %d.",
905 s->conf.num_queues,
906 VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED);
907 virtio_cleanup(vdev);
908 return;
909 }
910 if (s->conf.virtqueue_size <= 2) {
911 error_setg(errp, "invalid virtqueue_size property (= %" PRIu32 "), "
912 "must be > 2", s->conf.virtqueue_size);
913 return;
914 }
915 s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
916 s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
917 s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
918
919 s->ctrl_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, ctrl);
920 s->event_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, evt);
921 for (i = 0; i < s->conf.num_queues; i++) {
922 s->cmd_vqs[i] = virtio_add_queue(vdev, s->conf.virtqueue_size, cmd);
923 }
924 }
925
926 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
927 {
928 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
929 VirtIOSCSI *s = VIRTIO_SCSI(dev);
930 Error *err = NULL;
931
932 virtio_scsi_common_realize(dev,
933 virtio_scsi_handle_ctrl,
934 virtio_scsi_handle_event,
935 virtio_scsi_handle_cmd,
936 &err);
937 if (err != NULL) {
938 error_propagate(errp, err);
939 return;
940 }
941
942 scsi_bus_new(&s->bus, sizeof(s->bus), dev,
943 &virtio_scsi_scsi_info, vdev->bus_name);
944 /* override default SCSI bus hotplug-handler, with virtio-scsi's one */
945 qbus_set_hotplug_handler(BUS(&s->bus), OBJECT(dev));
946
947 virtio_scsi_dataplane_setup(s, errp);
948 }
949
950 void virtio_scsi_common_unrealize(DeviceState *dev)
951 {
952 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
953 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
954 int i;
955
956 virtio_delete_queue(vs->ctrl_vq);
957 virtio_delete_queue(vs->event_vq);
958 for (i = 0; i < vs->conf.num_queues; i++) {
959 virtio_delete_queue(vs->cmd_vqs[i]);
960 }
961 g_free(vs->cmd_vqs);
962 virtio_cleanup(vdev);
963 }
964
965 static void virtio_scsi_device_unrealize(DeviceState *dev)
966 {
967 VirtIOSCSI *s = VIRTIO_SCSI(dev);
968
969 qbus_set_hotplug_handler(BUS(&s->bus), NULL);
970 virtio_scsi_common_unrealize(dev);
971 }
972
973 static Property virtio_scsi_properties[] = {
974 DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues,
975 VIRTIO_SCSI_AUTO_NUM_QUEUES),
976 DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
977 parent_obj.conf.virtqueue_size, 256),
978 DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI,
979 parent_obj.conf.seg_max_adjust, true),
980 DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
981 0xFFFF),
982 DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
983 128),
984 DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
985 VIRTIO_SCSI_F_HOTPLUG, true),
986 DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
987 VIRTIO_SCSI_F_CHANGE, true),
988 DEFINE_PROP_LINK("iothread", VirtIOSCSI, parent_obj.conf.iothread,
989 TYPE_IOTHREAD, IOThread *),
990 DEFINE_PROP_END_OF_LIST(),
991 };
992
993 static const VMStateDescription vmstate_virtio_scsi = {
994 .name = "virtio-scsi",
995 .minimum_version_id = 1,
996 .version_id = 1,
997 .fields = (VMStateField[]) {
998 VMSTATE_VIRTIO_DEVICE,
999 VMSTATE_END_OF_LIST()
1000 },
1001 };
1002
1003 static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
1004 {
1005 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1006 DeviceClass *dc = DEVICE_CLASS(klass);
1007
1008 vdc->get_config = virtio_scsi_get_config;
1009 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1010 }
1011
1012 static void virtio_scsi_class_init(ObjectClass *klass, void *data)
1013 {
1014 DeviceClass *dc = DEVICE_CLASS(klass);
1015 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1016 HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1017
1018 device_class_set_props(dc, virtio_scsi_properties);
1019 dc->vmsd = &vmstate_virtio_scsi;
1020 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1021 vdc->realize = virtio_scsi_device_realize;
1022 vdc->unrealize = virtio_scsi_device_unrealize;
1023 vdc->set_config = virtio_scsi_set_config;
1024 vdc->get_features = virtio_scsi_get_features;
1025 vdc->reset = virtio_scsi_reset;
1026 vdc->start_ioeventfd = virtio_scsi_dataplane_start;
1027 vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
1028 hc->pre_plug = virtio_scsi_pre_hotplug;
1029 hc->plug = virtio_scsi_hotplug;
1030 hc->unplug = virtio_scsi_hotunplug;
1031 }
1032
1033 static const TypeInfo virtio_scsi_common_info = {
1034 .name = TYPE_VIRTIO_SCSI_COMMON,
1035 .parent = TYPE_VIRTIO_DEVICE,
1036 .instance_size = sizeof(VirtIOSCSICommon),
1037 .abstract = true,
1038 .class_init = virtio_scsi_common_class_init,
1039 };
1040
1041 static const TypeInfo virtio_scsi_info = {
1042 .name = TYPE_VIRTIO_SCSI,
1043 .parent = TYPE_VIRTIO_SCSI_COMMON,
1044 .instance_size = sizeof(VirtIOSCSI),
1045 .class_init = virtio_scsi_class_init,
1046 .interfaces = (InterfaceInfo[]) {
1047 { TYPE_HOTPLUG_HANDLER },
1048 { }
1049 }
1050 };
1051
1052 static void virtio_register_types(void)
1053 {
1054 type_register_static(&virtio_scsi_common_info);
1055 type_register_static(&virtio_scsi_info);
1056 }
1057
1058 type_init(virtio_register_types)