1
2
3
4
5
6
7
8
9
10
11
12
13
14#include "qemu/osdep.h"
15#include "qapi/error.h"
16#include "qemu/iov.h"
17#include "qemu/module.h"
18#include "qemu/error-report.h"
19#include "qemu/main-loop.h"
20#include "trace.h"
21#include "hw/block/block.h"
22#include "hw/qdev-properties.h"
23#include "sysemu/blockdev.h"
24#include "sysemu/block-ram-registrar.h"
25#include "sysemu/sysemu.h"
26#include "sysemu/runstate.h"
27#include "hw/virtio/virtio-blk.h"
28#include "dataplane/virtio-blk.h"
29#include "scsi/constants.h"
30#ifdef __linux__
31# include <scsi/sg.h>
32#endif
33#include "hw/virtio/virtio-bus.h"
34#include "migration/qemu-file-types.h"
35#include "hw/virtio/virtio-access.h"
36#include "hw/virtio/virtio-blk-common.h"
37#include "qemu/coroutine.h"
38
39static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
40 VirtIOBlockReq *req)
41{
42 req->dev = s;
43 req->vq = vq;
44 req->qiov.size = 0;
45 req->in_len = 0;
46 req->next = NULL;
47 req->mr_next = NULL;
48}
49
50static void virtio_blk_free_request(VirtIOBlockReq *req)
51{
52 g_free(req);
53}
54
55static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status)
56{
57 VirtIOBlock *s = req->dev;
58 VirtIODevice *vdev = VIRTIO_DEVICE(s);
59
60 trace_virtio_blk_req_complete(vdev, req, status);
61
62 stb_p(&req->in->status, status);
63 iov_discard_undo(&req->inhdr_undo);
64 iov_discard_undo(&req->outhdr_undo);
65 virtqueue_push(req->vq, &req->elem, req->in_len);
66 if (s->dataplane_started && !s->dataplane_disabled) {
67 virtio_blk_data_plane_notify(s->dataplane, req->vq);
68 } else {
69 virtio_notify(vdev, req->vq);
70 }
71}
72
73static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
74 bool is_read, bool acct_failed)
75{
76 VirtIOBlock *s = req->dev;
77 BlockErrorAction action = blk_get_error_action(s->blk, is_read, error);
78
79 if (action == BLOCK_ERROR_ACTION_STOP) {
80
81
82 req->mr_next = NULL;
83 req->next = s->rq;
84 s->rq = req;
85 } else if (action == BLOCK_ERROR_ACTION_REPORT) {
86 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
87 if (acct_failed) {
88 block_acct_failed(blk_get_stats(s->blk), &req->acct);
89 }
90 virtio_blk_free_request(req);
91 }
92
93 blk_error_action(s->blk, action, is_read, error);
94 return action != BLOCK_ERROR_ACTION_IGNORE;
95}
96
97static void virtio_blk_rw_complete(void *opaque, int ret)
98{
99 VirtIOBlockReq *next = opaque;
100 VirtIOBlock *s = next->dev;
101 VirtIODevice *vdev = VIRTIO_DEVICE(s);
102
103 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
104 while (next) {
105 VirtIOBlockReq *req = next;
106 next = req->mr_next;
107 trace_virtio_blk_rw_complete(vdev, req, ret);
108
109 if (req->qiov.nalloc != -1) {
110
111
112
113 qemu_iovec_destroy(&req->qiov);
114 }
115
116 if (ret) {
117 int p = virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type);
118 bool is_read = !(p & VIRTIO_BLK_T_OUT);
119
120
121
122
123
124
125
126
127 if (virtio_blk_handle_rw_error(req, -ret, is_read, true)) {
128 continue;
129 }
130 }
131
132 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
133 block_acct_done(blk_get_stats(s->blk), &req->acct);
134 virtio_blk_free_request(req);
135 }
136 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
137}
138
139static void virtio_blk_flush_complete(void *opaque, int ret)
140{
141 VirtIOBlockReq *req = opaque;
142 VirtIOBlock *s = req->dev;
143
144 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
145 if (ret) {
146 if (virtio_blk_handle_rw_error(req, -ret, 0, true)) {
147 goto out;
148 }
149 }
150
151 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
152 block_acct_done(blk_get_stats(s->blk), &req->acct);
153 virtio_blk_free_request(req);
154
155out:
156 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
157}
158
159static void virtio_blk_discard_write_zeroes_complete(void *opaque, int ret)
160{
161 VirtIOBlockReq *req = opaque;
162 VirtIOBlock *s = req->dev;
163 bool is_write_zeroes = (virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type) &
164 ~VIRTIO_BLK_T_BARRIER) == VIRTIO_BLK_T_WRITE_ZEROES;
165
166 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
167 if (ret) {
168 if (virtio_blk_handle_rw_error(req, -ret, false, is_write_zeroes)) {
169 goto out;
170 }
171 }
172
173 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
174 if (is_write_zeroes) {
175 block_acct_done(blk_get_stats(s->blk), &req->acct);
176 }
177 virtio_blk_free_request(req);
178
179out:
180 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
181}
182
183#ifdef __linux__
184
185typedef struct {
186 VirtIOBlockReq *req;
187 struct sg_io_hdr hdr;
188} VirtIOBlockIoctlReq;
189
190static void virtio_blk_ioctl_complete(void *opaque, int status)
191{
192 VirtIOBlockIoctlReq *ioctl_req = opaque;
193 VirtIOBlockReq *req = ioctl_req->req;
194 VirtIOBlock *s = req->dev;
195 VirtIODevice *vdev = VIRTIO_DEVICE(s);
196 struct virtio_scsi_inhdr *scsi;
197 struct sg_io_hdr *hdr;
198
199 scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base;
200
201 if (status) {
202 status = VIRTIO_BLK_S_UNSUPP;
203 virtio_stl_p(vdev, &scsi->errors, 255);
204 goto out;
205 }
206
207 hdr = &ioctl_req->hdr;
208
209
210
211
212
213
214
215 if (hdr->status == 0 && hdr->sb_len_wr > 0) {
216 hdr->status = CHECK_CONDITION;
217 }
218
219 virtio_stl_p(vdev, &scsi->errors,
220 hdr->status | (hdr->msg_status << 8) |
221 (hdr->host_status << 16) | (hdr->driver_status << 24));
222 virtio_stl_p(vdev, &scsi->residual, hdr->resid);
223 virtio_stl_p(vdev, &scsi->sense_len, hdr->sb_len_wr);
224 virtio_stl_p(vdev, &scsi->data_len, hdr->dxfer_len);
225
226out:
227 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
228 virtio_blk_req_complete(req, status);
229 virtio_blk_free_request(req);
230 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
231 g_free(ioctl_req);
232}
233
234#endif
235
236static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s, VirtQueue *vq)
237{
238 VirtIOBlockReq *req = virtqueue_pop(vq, sizeof(VirtIOBlockReq));
239
240 if (req) {
241 virtio_blk_init_request(s, vq, req);
242 }
243 return req;
244}
245
246static int virtio_blk_handle_scsi_req(VirtIOBlockReq *req)
247{
248 int status = VIRTIO_BLK_S_OK;
249 struct virtio_scsi_inhdr *scsi = NULL;
250 VirtIOBlock *blk = req->dev;
251 VirtIODevice *vdev = VIRTIO_DEVICE(blk);
252 VirtQueueElement *elem = &req->elem;
253
254#ifdef __linux__
255 int i;
256 VirtIOBlockIoctlReq *ioctl_req;
257 BlockAIOCB *acb;
258#endif
259
260
261
262
263
264
265
266
267 if (elem->out_num < 2 || elem->in_num < 3) {
268 status = VIRTIO_BLK_S_IOERR;
269 goto fail;
270 }
271
272
273
274
275
276 scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base;
277
278 if (!virtio_has_feature(blk->host_features, VIRTIO_BLK_F_SCSI)) {
279 status = VIRTIO_BLK_S_UNSUPP;
280 goto fail;
281 }
282
283
284
285
286 if (elem->out_num > 2 && elem->in_num > 3) {
287 status = VIRTIO_BLK_S_UNSUPP;
288 goto fail;
289 }
290
291#ifdef __linux__
292 ioctl_req = g_new0(VirtIOBlockIoctlReq, 1);
293 ioctl_req->req = req;
294 ioctl_req->hdr.interface_id = 'S';
295 ioctl_req->hdr.cmd_len = elem->out_sg[1].iov_len;
296 ioctl_req->hdr.cmdp = elem->out_sg[1].iov_base;
297 ioctl_req->hdr.dxfer_len = 0;
298
299 if (elem->out_num > 2) {
300
301
302
303
304 ioctl_req->hdr.dxfer_direction = SG_DXFER_TO_DEV;
305 ioctl_req->hdr.iovec_count = elem->out_num - 2;
306
307 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) {
308 ioctl_req->hdr.dxfer_len += elem->out_sg[i + 2].iov_len;
309 }
310
311 ioctl_req->hdr.dxferp = elem->out_sg + 2;
312
313 } else if (elem->in_num > 3) {
314
315
316
317
318 ioctl_req->hdr.dxfer_direction = SG_DXFER_FROM_DEV;
319 ioctl_req->hdr.iovec_count = elem->in_num - 3;
320 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) {
321 ioctl_req->hdr.dxfer_len += elem->in_sg[i].iov_len;
322 }
323
324 ioctl_req->hdr.dxferp = elem->in_sg;
325 } else {
326
327
328
329 ioctl_req->hdr.dxfer_direction = SG_DXFER_NONE;
330 }
331
332 ioctl_req->hdr.sbp = elem->in_sg[elem->in_num - 3].iov_base;
333 ioctl_req->hdr.mx_sb_len = elem->in_sg[elem->in_num - 3].iov_len;
334
335 acb = blk_aio_ioctl(blk->blk, SG_IO, &ioctl_req->hdr,
336 virtio_blk_ioctl_complete, ioctl_req);
337 if (!acb) {
338 g_free(ioctl_req);
339 status = VIRTIO_BLK_S_UNSUPP;
340 goto fail;
341 }
342 return -EINPROGRESS;
343#else
344 abort();
345#endif
346
347fail:
348
349 if (scsi) {
350 virtio_stl_p(vdev, &scsi->errors, 255);
351 }
352 return status;
353}
354
355static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
356{
357 int status;
358
359 status = virtio_blk_handle_scsi_req(req);
360 if (status != -EINPROGRESS) {
361 virtio_blk_req_complete(req, status);
362 virtio_blk_free_request(req);
363 }
364}
365
366static inline void submit_requests(VirtIOBlock *s, MultiReqBuffer *mrb,
367 int start, int num_reqs, int niov)
368{
369 BlockBackend *blk = s->blk;
370 QEMUIOVector *qiov = &mrb->reqs[start]->qiov;
371 int64_t sector_num = mrb->reqs[start]->sector_num;
372 bool is_write = mrb->is_write;
373 BdrvRequestFlags flags = 0;
374
375 if (num_reqs > 1) {
376 int i;
377 struct iovec *tmp_iov = qiov->iov;
378 int tmp_niov = qiov->niov;
379
380
381
382
383 qemu_iovec_init(qiov, niov);
384
385 for (i = 0; i < tmp_niov; i++) {
386 qemu_iovec_add(qiov, tmp_iov[i].iov_base, tmp_iov[i].iov_len);
387 }
388
389 for (i = start + 1; i < start + num_reqs; i++) {
390 qemu_iovec_concat(qiov, &mrb->reqs[i]->qiov, 0,
391 mrb->reqs[i]->qiov.size);
392 mrb->reqs[i - 1]->mr_next = mrb->reqs[i];
393 }
394
395 trace_virtio_blk_submit_multireq(VIRTIO_DEVICE(mrb->reqs[start]->dev),
396 mrb, start, num_reqs,
397 sector_num << BDRV_SECTOR_BITS,
398 qiov->size, is_write);
399 block_acct_merge_done(blk_get_stats(blk),
400 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ,
401 num_reqs - 1);
402 }
403
404 if (blk_ram_registrar_ok(&s->blk_ram_registrar)) {
405 flags |= BDRV_REQ_REGISTERED_BUF;
406 }
407
408 if (is_write) {
409 blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov,
410 flags, virtio_blk_rw_complete,
411 mrb->reqs[start]);
412 } else {
413 blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov,
414 flags, virtio_blk_rw_complete,
415 mrb->reqs[start]);
416 }
417}
418
419static int multireq_compare(const void *a, const void *b)
420{
421 const VirtIOBlockReq *req1 = *(VirtIOBlockReq **)a,
422 *req2 = *(VirtIOBlockReq **)b;
423
424
425
426
427
428 if (req1->sector_num > req2->sector_num) {
429 return 1;
430 } else if (req1->sector_num < req2->sector_num) {
431 return -1;
432 } else {
433 return 0;
434 }
435}
436
437static void virtio_blk_submit_multireq(VirtIOBlock *s, MultiReqBuffer *mrb)
438{
439 int i = 0, start = 0, num_reqs = 0, niov = 0, nb_sectors = 0;
440 uint32_t max_transfer;
441 int64_t sector_num = 0;
442
443 if (mrb->num_reqs == 1) {
444 submit_requests(s, mrb, 0, 1, -1);
445 mrb->num_reqs = 0;
446 return;
447 }
448
449 max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk);
450
451 qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs),
452 &multireq_compare);
453
454 for (i = 0; i < mrb->num_reqs; i++) {
455 VirtIOBlockReq *req = mrb->reqs[i];
456 if (num_reqs > 0) {
457
458
459
460
461
462
463 if (sector_num + nb_sectors != req->sector_num ||
464 niov > blk_get_max_iov(s->blk) - req->qiov.niov ||
465 req->qiov.size > max_transfer ||
466 nb_sectors > (max_transfer -
467 req->qiov.size) / BDRV_SECTOR_SIZE) {
468 submit_requests(s, mrb, start, num_reqs, niov);
469 num_reqs = 0;
470 }
471 }
472
473 if (num_reqs == 0) {
474 sector_num = req->sector_num;
475 nb_sectors = niov = 0;
476 start = i;
477 }
478
479 nb_sectors += req->qiov.size / BDRV_SECTOR_SIZE;
480 niov += req->qiov.niov;
481 num_reqs++;
482 }
483
484 submit_requests(s, mrb, start, num_reqs, niov);
485 mrb->num_reqs = 0;
486}
487
488static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb)
489{
490 VirtIOBlock *s = req->dev;
491
492 block_acct_start(blk_get_stats(s->blk), &req->acct, 0,
493 BLOCK_ACCT_FLUSH);
494
495
496
497
498 if (mrb->is_write && mrb->num_reqs > 0) {
499 virtio_blk_submit_multireq(s, mrb);
500 }
501 blk_aio_flush(s->blk, virtio_blk_flush_complete, req);
502}
503
504static bool virtio_blk_sect_range_ok(VirtIOBlock *dev,
505 uint64_t sector, size_t size)
506{
507 uint64_t nb_sectors = size >> BDRV_SECTOR_BITS;
508 uint64_t total_sectors;
509
510 if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
511 return false;
512 }
513 if (sector & dev->sector_mask) {
514 return false;
515 }
516 if (size % dev->conf.conf.logical_block_size) {
517 return false;
518 }
519 blk_get_geometry(dev->blk, &total_sectors);
520 if (sector > total_sectors || nb_sectors > total_sectors - sector) {
521 return false;
522 }
523 return true;
524}
525
526static uint8_t virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq *req,
527 struct virtio_blk_discard_write_zeroes *dwz_hdr, bool is_write_zeroes)
528{
529 VirtIOBlock *s = req->dev;
530 VirtIODevice *vdev = VIRTIO_DEVICE(s);
531 uint64_t sector;
532 uint32_t num_sectors, flags, max_sectors;
533 uint8_t err_status;
534 int bytes;
535
536 sector = virtio_ldq_p(vdev, &dwz_hdr->sector);
537 num_sectors = virtio_ldl_p(vdev, &dwz_hdr->num_sectors);
538 flags = virtio_ldl_p(vdev, &dwz_hdr->flags);
539 max_sectors = is_write_zeroes ? s->conf.max_write_zeroes_sectors :
540 s->conf.max_discard_sectors;
541
542
543
544
545
546
547 if (unlikely(num_sectors > max_sectors)) {
548 err_status = VIRTIO_BLK_S_IOERR;
549 goto err;
550 }
551
552 bytes = num_sectors << BDRV_SECTOR_BITS;
553
554 if (unlikely(!virtio_blk_sect_range_ok(s, sector, bytes))) {
555 err_status = VIRTIO_BLK_S_IOERR;
556 goto err;
557 }
558
559
560
561
562
563 if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
564 err_status = VIRTIO_BLK_S_UNSUPP;
565 goto err;
566 }
567
568 if (is_write_zeroes) {
569 int blk_aio_flags = 0;
570
571 if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) {
572 blk_aio_flags |= BDRV_REQ_MAY_UNMAP;
573 }
574
575 block_acct_start(blk_get_stats(s->blk), &req->acct, bytes,
576 BLOCK_ACCT_WRITE);
577
578 blk_aio_pwrite_zeroes(s->blk, sector << BDRV_SECTOR_BITS,
579 bytes, blk_aio_flags,
580 virtio_blk_discard_write_zeroes_complete, req);
581 } else {
582
583
584
585
586 if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
587 err_status = VIRTIO_BLK_S_UNSUPP;
588 goto err;
589 }
590
591 blk_aio_pdiscard(s->blk, sector << BDRV_SECTOR_BITS, bytes,
592 virtio_blk_discard_write_zeroes_complete, req);
593 }
594
595 return VIRTIO_BLK_S_OK;
596
597err:
598 if (is_write_zeroes) {
599 block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_WRITE);
600 }
601 return err_status;
602}
603
604static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
605{
606 uint32_t type;
607 struct iovec *in_iov = req->elem.in_sg;
608 struct iovec *out_iov = req->elem.out_sg;
609 unsigned in_num = req->elem.in_num;
610 unsigned out_num = req->elem.out_num;
611 VirtIOBlock *s = req->dev;
612 VirtIODevice *vdev = VIRTIO_DEVICE(s);
613
614 if (req->elem.out_num < 1 || req->elem.in_num < 1) {
615 virtio_error(vdev, "virtio-blk missing headers");
616 return -1;
617 }
618
619 if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
620 sizeof(req->out)) != sizeof(req->out))) {
621 virtio_error(vdev, "virtio-blk request outhdr too short");
622 return -1;
623 }
624
625 iov_discard_front_undoable(&out_iov, &out_num, sizeof(req->out),
626 &req->outhdr_undo);
627
628 if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
629 virtio_error(vdev, "virtio-blk request inhdr too short");
630 iov_discard_undo(&req->outhdr_undo);
631 return -1;
632 }
633
634
635 req->in_len = iov_size(in_iov, in_num);
636 req->in = (void *)in_iov[in_num - 1].iov_base
637 + in_iov[in_num - 1].iov_len
638 - sizeof(struct virtio_blk_inhdr);
639 iov_discard_back_undoable(in_iov, &in_num, sizeof(struct virtio_blk_inhdr),
640 &req->inhdr_undo);
641
642 type = virtio_ldl_p(vdev, &req->out.type);
643
644
645
646
647 switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) {
648 case VIRTIO_BLK_T_IN:
649 {
650 bool is_write = type & VIRTIO_BLK_T_OUT;
651 req->sector_num = virtio_ldq_p(vdev, &req->out.sector);
652
653 if (is_write) {
654 qemu_iovec_init_external(&req->qiov, out_iov, out_num);
655 trace_virtio_blk_handle_write(vdev, req, req->sector_num,
656 req->qiov.size / BDRV_SECTOR_SIZE);
657 } else {
658 qemu_iovec_init_external(&req->qiov, in_iov, in_num);
659 trace_virtio_blk_handle_read(vdev, req, req->sector_num,
660 req->qiov.size / BDRV_SECTOR_SIZE);
661 }
662
663 if (!virtio_blk_sect_range_ok(s, req->sector_num, req->qiov.size)) {
664 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
665 block_acct_invalid(blk_get_stats(s->blk),
666 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
667 virtio_blk_free_request(req);
668 return 0;
669 }
670
671 block_acct_start(blk_get_stats(s->blk), &req->acct, req->qiov.size,
672 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
673
674
675
676 if (mrb->num_reqs > 0 && (mrb->num_reqs == VIRTIO_BLK_MAX_MERGE_REQS ||
677 is_write != mrb->is_write ||
678 !s->conf.request_merging)) {
679 virtio_blk_submit_multireq(s, mrb);
680 }
681
682 assert(mrb->num_reqs < VIRTIO_BLK_MAX_MERGE_REQS);
683 mrb->reqs[mrb->num_reqs++] = req;
684 mrb->is_write = is_write;
685 break;
686 }
687 case VIRTIO_BLK_T_FLUSH:
688 virtio_blk_handle_flush(req, mrb);
689 break;
690 case VIRTIO_BLK_T_SCSI_CMD:
691 virtio_blk_handle_scsi(req);
692 break;
693 case VIRTIO_BLK_T_GET_ID:
694 {
695
696
697
698
699 const char *serial = s->conf.serial ? s->conf.serial : "";
700 size_t size = MIN(strlen(serial) + 1,
701 MIN(iov_size(in_iov, in_num),
702 VIRTIO_BLK_ID_BYTES));
703 iov_from_buf(in_iov, in_num, 0, serial, size);
704 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
705 virtio_blk_free_request(req);
706 break;
707 }
708
709
710
711
712
713 case VIRTIO_BLK_T_DISCARD & ~VIRTIO_BLK_T_OUT:
714 case VIRTIO_BLK_T_WRITE_ZEROES & ~VIRTIO_BLK_T_OUT:
715 {
716 struct virtio_blk_discard_write_zeroes dwz_hdr;
717 size_t out_len = iov_size(out_iov, out_num);
718 bool is_write_zeroes = (type & ~VIRTIO_BLK_T_BARRIER) ==
719 VIRTIO_BLK_T_WRITE_ZEROES;
720 uint8_t err_status;
721
722
723
724
725
726 if (unlikely(!(type & VIRTIO_BLK_T_OUT) ||
727 out_len > sizeof(dwz_hdr))) {
728 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
729 virtio_blk_free_request(req);
730 return 0;
731 }
732
733 if (unlikely(iov_to_buf(out_iov, out_num, 0, &dwz_hdr,
734 sizeof(dwz_hdr)) != sizeof(dwz_hdr))) {
735 iov_discard_undo(&req->inhdr_undo);
736 iov_discard_undo(&req->outhdr_undo);
737 virtio_error(vdev, "virtio-blk discard/write_zeroes header"
738 " too short");
739 return -1;
740 }
741
742 err_status = virtio_blk_handle_discard_write_zeroes(req, &dwz_hdr,
743 is_write_zeroes);
744 if (err_status != VIRTIO_BLK_S_OK) {
745 virtio_blk_req_complete(req, err_status);
746 virtio_blk_free_request(req);
747 }
748
749 break;
750 }
751 default:
752 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
753 virtio_blk_free_request(req);
754 }
755 return 0;
756}
757
758void virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq)
759{
760 VirtIOBlockReq *req;
761 MultiReqBuffer mrb = {};
762 bool suppress_notifications = virtio_queue_get_notification(vq);
763
764 aio_context_acquire(blk_get_aio_context(s->blk));
765 blk_io_plug(s->blk);
766
767 do {
768 if (suppress_notifications) {
769 virtio_queue_set_notification(vq, 0);
770 }
771
772 while ((req = virtio_blk_get_request(s, vq))) {
773 if (virtio_blk_handle_request(req, &mrb)) {
774 virtqueue_detach_element(req->vq, &req->elem, 0);
775 virtio_blk_free_request(req);
776 break;
777 }
778 }
779
780 if (suppress_notifications) {
781 virtio_queue_set_notification(vq, 1);
782 }
783 } while (!virtio_queue_empty(vq));
784
785 if (mrb.num_reqs) {
786 virtio_blk_submit_multireq(s, &mrb);
787 }
788
789 blk_io_unplug(s->blk);
790 aio_context_release(blk_get_aio_context(s->blk));
791}
792
793static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
794{
795 VirtIOBlock *s = (VirtIOBlock *)vdev;
796
797 if (s->dataplane && !s->dataplane_started) {
798
799
800
801 virtio_device_start_ioeventfd(vdev);
802 if (!s->dataplane_disabled) {
803 return;
804 }
805 }
806 virtio_blk_handle_vq(s, vq);
807}
808
809void virtio_blk_process_queued_requests(VirtIOBlock *s, bool is_bh)
810{
811 VirtIOBlockReq *req = s->rq;
812 MultiReqBuffer mrb = {};
813
814 s->rq = NULL;
815
816 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
817 while (req) {
818 VirtIOBlockReq *next = req->next;
819 if (virtio_blk_handle_request(req, &mrb)) {
820
821
822
823 while (req) {
824 next = req->next;
825 virtqueue_detach_element(req->vq, &req->elem, 0);
826 virtio_blk_free_request(req);
827 req = next;
828 }
829 break;
830 }
831 req = next;
832 }
833
834 if (mrb.num_reqs) {
835 virtio_blk_submit_multireq(s, &mrb);
836 }
837 if (is_bh) {
838 blk_dec_in_flight(s->conf.conf.blk);
839 }
840 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
841}
842
843static void virtio_blk_dma_restart_bh(void *opaque)
844{
845 VirtIOBlock *s = opaque;
846
847 qemu_bh_delete(s->bh);
848 s->bh = NULL;
849
850 virtio_blk_process_queued_requests(s, true);
851}
852
853static void virtio_blk_dma_restart_cb(void *opaque, bool running,
854 RunState state)
855{
856 VirtIOBlock *s = opaque;
857 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
858 VirtioBusState *bus = VIRTIO_BUS(qbus);
859
860 if (!running) {
861 return;
862 }
863
864
865
866
867
868 if (!s->bh && !virtio_bus_ioeventfd_enabled(bus)) {
869 s->bh = aio_bh_new(blk_get_aio_context(s->conf.conf.blk),
870 virtio_blk_dma_restart_bh, s);
871 blk_inc_in_flight(s->conf.conf.blk);
872 qemu_bh_schedule(s->bh);
873 }
874}
875
876static void virtio_blk_reset(VirtIODevice *vdev)
877{
878 VirtIOBlock *s = VIRTIO_BLK(vdev);
879 AioContext *ctx;
880 VirtIOBlockReq *req;
881
882 ctx = blk_get_aio_context(s->blk);
883 aio_context_acquire(ctx);
884 blk_drain(s->blk);
885
886
887
888 while (s->rq) {
889 req = s->rq;
890 s->rq = req->next;
891 virtqueue_detach_element(req->vq, &req->elem, 0);
892 virtio_blk_free_request(req);
893 }
894
895 aio_context_release(ctx);
896
897 assert(!s->dataplane_started);
898 blk_set_enable_write_cache(s->blk, s->original_wce);
899}
900
901
902
903static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
904{
905 VirtIOBlock *s = VIRTIO_BLK(vdev);
906 BlockConf *conf = &s->conf.conf;
907 struct virtio_blk_config blkcfg;
908 uint64_t capacity;
909 int64_t length;
910 int blk_size = conf->logical_block_size;
911
912 blk_get_geometry(s->blk, &capacity);
913 memset(&blkcfg, 0, sizeof(blkcfg));
914 virtio_stq_p(vdev, &blkcfg.capacity, capacity);
915 virtio_stl_p(vdev, &blkcfg.seg_max,
916 s->conf.seg_max_adjust ? s->conf.queue_size - 2 : 128 - 2);
917 virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls);
918 virtio_stl_p(vdev, &blkcfg.blk_size, blk_size);
919 virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size);
920 virtio_stl_p(vdev, &blkcfg.opt_io_size, conf->opt_io_size / blk_size);
921 blkcfg.geometry.heads = conf->heads;
922
923
924
925
926
927
928
929
930
931
932
933 length = blk_getlength(s->blk);
934 if (length > 0 && length / conf->heads / conf->secs % blk_size) {
935 blkcfg.geometry.sectors = conf->secs & ~s->sector_mask;
936 } else {
937 blkcfg.geometry.sectors = conf->secs;
938 }
939 blkcfg.size_max = 0;
940 blkcfg.physical_block_exp = get_physical_block_exp(conf);
941 blkcfg.alignment_offset = 0;
942 blkcfg.wce = blk_enable_write_cache(s->blk);
943 virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues);
944 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD)) {
945 uint32_t discard_granularity = conf->discard_granularity;
946 if (discard_granularity == -1 || !s->conf.report_discard_granularity) {
947 discard_granularity = blk_size;
948 }
949 virtio_stl_p(vdev, &blkcfg.max_discard_sectors,
950 s->conf.max_discard_sectors);
951 virtio_stl_p(vdev, &blkcfg.discard_sector_alignment,
952 discard_granularity >> BDRV_SECTOR_BITS);
953
954
955
956
957
958 virtio_stl_p(vdev, &blkcfg.max_discard_seg, 1);
959 }
960 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES)) {
961 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_sectors,
962 s->conf.max_write_zeroes_sectors);
963 blkcfg.write_zeroes_may_unmap = 1;
964 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_seg, 1);
965 }
966 memcpy(config, &blkcfg, s->config_size);
967}
968
969static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
970{
971 VirtIOBlock *s = VIRTIO_BLK(vdev);
972 struct virtio_blk_config blkcfg;
973
974 memcpy(&blkcfg, config, s->config_size);
975
976 aio_context_acquire(blk_get_aio_context(s->blk));
977 blk_set_enable_write_cache(s->blk, blkcfg.wce != 0);
978 aio_context_release(blk_get_aio_context(s->blk));
979}
980
981static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features,
982 Error **errp)
983{
984 VirtIOBlock *s = VIRTIO_BLK(vdev);
985
986
987 features |= s->host_features;
988
989 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
990 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
991 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
992 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
993 if (virtio_has_feature(features, VIRTIO_F_VERSION_1)) {
994 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_SCSI)) {
995 error_setg(errp, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0");
996 return 0;
997 }
998 } else {
999 virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT);
1000 virtio_add_feature(&features, VIRTIO_BLK_F_SCSI);
1001 }
1002
1003 if (blk_enable_write_cache(s->blk) ||
1004 (s->conf.x_enable_wce_if_config_wce &&
1005 virtio_has_feature(features, VIRTIO_BLK_F_CONFIG_WCE))) {
1006 virtio_add_feature(&features, VIRTIO_BLK_F_WCE);
1007 }
1008 if (!blk_is_writable(s->blk)) {
1009 virtio_add_feature(&features, VIRTIO_BLK_F_RO);
1010 }
1011 if (s->conf.num_queues > 1) {
1012 virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
1013 }
1014
1015 return features;
1016}
1017
1018static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
1019{
1020 VirtIOBlock *s = VIRTIO_BLK(vdev);
1021
1022 if (!(status & (VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK))) {
1023 assert(!s->dataplane_started);
1024 }
1025
1026 if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
1027 return;
1028 }
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045 if (!virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) {
1046 aio_context_acquire(blk_get_aio_context(s->blk));
1047 blk_set_enable_write_cache(s->blk,
1048 virtio_vdev_has_feature(vdev,
1049 VIRTIO_BLK_F_WCE));
1050 aio_context_release(blk_get_aio_context(s->blk));
1051 }
1052}
1053
1054static void virtio_blk_save_device(VirtIODevice *vdev, QEMUFile *f)
1055{
1056 VirtIOBlock *s = VIRTIO_BLK(vdev);
1057 VirtIOBlockReq *req = s->rq;
1058
1059 while (req) {
1060 qemu_put_sbyte(f, 1);
1061
1062 if (s->conf.num_queues > 1) {
1063 qemu_put_be32(f, virtio_get_queue_index(req->vq));
1064 }
1065
1066 qemu_put_virtqueue_element(vdev, f, &req->elem);
1067 req = req->next;
1068 }
1069 qemu_put_sbyte(f, 0);
1070}
1071
1072static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f,
1073 int version_id)
1074{
1075 VirtIOBlock *s = VIRTIO_BLK(vdev);
1076
1077 while (qemu_get_sbyte(f)) {
1078 unsigned nvqs = s->conf.num_queues;
1079 unsigned vq_idx = 0;
1080 VirtIOBlockReq *req;
1081
1082 if (nvqs > 1) {
1083 vq_idx = qemu_get_be32(f);
1084
1085 if (vq_idx >= nvqs) {
1086 error_report("Invalid virtqueue index in request list: %#x",
1087 vq_idx);
1088 return -EINVAL;
1089 }
1090 }
1091
1092 req = qemu_get_virtqueue_element(vdev, f, sizeof(VirtIOBlockReq));
1093 virtio_blk_init_request(s, virtio_get_queue(vdev, vq_idx), req);
1094 req->next = s->rq;
1095 s->rq = req;
1096 }
1097
1098 return 0;
1099}
1100
1101static void virtio_resize_cb(void *opaque)
1102{
1103 VirtIODevice *vdev = opaque;
1104
1105 assert(qemu_get_current_aio_context() == qemu_get_aio_context());
1106 virtio_notify_config(vdev);
1107}
1108
1109static void virtio_blk_resize(void *opaque)
1110{
1111 VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
1112
1113
1114
1115
1116
1117
1118 aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev);
1119}
1120
1121static const BlockDevOps virtio_block_ops = {
1122 .resize_cb = virtio_blk_resize,
1123};
1124
1125static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
1126{
1127 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1128 VirtIOBlock *s = VIRTIO_BLK(dev);
1129 VirtIOBlkConf *conf = &s->conf;
1130 Error *err = NULL;
1131 unsigned i;
1132
1133 if (!conf->conf.blk) {
1134 error_setg(errp, "drive property not set");
1135 return;
1136 }
1137 if (!blk_is_inserted(conf->conf.blk)) {
1138 error_setg(errp, "Device needs media, but drive is empty");
1139 return;
1140 }
1141 if (conf->num_queues == VIRTIO_BLK_AUTO_NUM_QUEUES) {
1142 conf->num_queues = 1;
1143 }
1144 if (!conf->num_queues) {
1145 error_setg(errp, "num-queues property must be larger than 0");
1146 return;
1147 }
1148 if (conf->queue_size <= 2) {
1149 error_setg(errp, "invalid queue-size property (%" PRIu16 "), "
1150 "must be > 2", conf->queue_size);
1151 return;
1152 }
1153 if (!is_power_of_2(conf->queue_size) ||
1154 conf->queue_size > VIRTQUEUE_MAX_SIZE) {
1155 error_setg(errp, "invalid queue-size property (%" PRIu16 "), "
1156 "must be a power of 2 (max %d)",
1157 conf->queue_size, VIRTQUEUE_MAX_SIZE);
1158 return;
1159 }
1160
1161 if (!blkconf_apply_backend_options(&conf->conf,
1162 !blk_supports_write_perm(conf->conf.blk),
1163 true, errp)) {
1164 return;
1165 }
1166 s->original_wce = blk_enable_write_cache(conf->conf.blk);
1167 if (!blkconf_geometry(&conf->conf, NULL, 65535, 255, 255, errp)) {
1168 return;
1169 }
1170
1171 if (!blkconf_blocksizes(&conf->conf, errp)) {
1172 return;
1173 }
1174
1175 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD) &&
1176 (!conf->max_discard_sectors ||
1177 conf->max_discard_sectors > BDRV_REQUEST_MAX_SECTORS)) {
1178 error_setg(errp, "invalid max-discard-sectors property (%" PRIu32 ")"
1179 ", must be between 1 and %d",
1180 conf->max_discard_sectors, (int)BDRV_REQUEST_MAX_SECTORS);
1181 return;
1182 }
1183
1184 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES) &&
1185 (!conf->max_write_zeroes_sectors ||
1186 conf->max_write_zeroes_sectors > BDRV_REQUEST_MAX_SECTORS)) {
1187 error_setg(errp, "invalid max-write-zeroes-sectors property (%" PRIu32
1188 "), must be between 1 and %d",
1189 conf->max_write_zeroes_sectors,
1190 (int)BDRV_REQUEST_MAX_SECTORS);
1191 return;
1192 }
1193
1194 s->config_size = virtio_get_config_size(&virtio_blk_cfg_size_params,
1195 s->host_features);
1196 virtio_init(vdev, VIRTIO_ID_BLOCK, s->config_size);
1197
1198 s->blk = conf->conf.blk;
1199 s->rq = NULL;
1200 s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1;
1201
1202 for (i = 0; i < conf->num_queues; i++) {
1203 virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output);
1204 }
1205 qemu_coroutine_inc_pool_size(conf->num_queues * conf->queue_size / 2);
1206 virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err);
1207 if (err != NULL) {
1208 error_propagate(errp, err);
1209 for (i = 0; i < conf->num_queues; i++) {
1210 virtio_del_queue(vdev, i);
1211 }
1212 virtio_cleanup(vdev);
1213 return;
1214 }
1215
1216 s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
1217 blk_ram_registrar_init(&s->blk_ram_registrar, s->blk);
1218 blk_set_dev_ops(s->blk, &virtio_block_ops, s);
1219
1220 blk_iostatus_enable(s->blk);
1221
1222 add_boot_device_lchs(dev, "/disk@0,0",
1223 conf->conf.lcyls,
1224 conf->conf.lheads,
1225 conf->conf.lsecs);
1226}
1227
1228static void virtio_blk_device_unrealize(DeviceState *dev)
1229{
1230 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1231 VirtIOBlock *s = VIRTIO_BLK(dev);
1232 VirtIOBlkConf *conf = &s->conf;
1233 unsigned i;
1234
1235 blk_drain(s->blk);
1236 del_boot_device_lchs(dev, "/disk@0,0");
1237 virtio_blk_data_plane_destroy(s->dataplane);
1238 s->dataplane = NULL;
1239 for (i = 0; i < conf->num_queues; i++) {
1240 virtio_del_queue(vdev, i);
1241 }
1242 qemu_coroutine_dec_pool_size(conf->num_queues * conf->queue_size / 2);
1243 blk_ram_registrar_destroy(&s->blk_ram_registrar);
1244 qemu_del_vm_change_state_handler(s->change);
1245 blockdev_mark_auto_del(s->blk);
1246 virtio_cleanup(vdev);
1247}
1248
1249static void virtio_blk_instance_init(Object *obj)
1250{
1251 VirtIOBlock *s = VIRTIO_BLK(obj);
1252
1253 device_add_bootindex_property(obj, &s->conf.conf.bootindex,
1254 "bootindex", "/disk@0,0",
1255 DEVICE(obj));
1256}
1257
1258static const VMStateDescription vmstate_virtio_blk = {
1259 .name = "virtio-blk",
1260 .minimum_version_id = 2,
1261 .version_id = 2,
1262 .fields = (VMStateField[]) {
1263 VMSTATE_VIRTIO_DEVICE,
1264 VMSTATE_END_OF_LIST()
1265 },
1266};
1267
1268static Property virtio_blk_properties[] = {
1269 DEFINE_BLOCK_PROPERTIES(VirtIOBlock, conf.conf),
1270 DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock, conf.conf),
1271 DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, conf.conf),
1272 DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial),
1273 DEFINE_PROP_BIT64("config-wce", VirtIOBlock, host_features,
1274 VIRTIO_BLK_F_CONFIG_WCE, true),
1275#ifdef __linux__
1276 DEFINE_PROP_BIT64("scsi", VirtIOBlock, host_features,
1277 VIRTIO_BLK_F_SCSI, false),
1278#endif
1279 DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0,
1280 true),
1281 DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues,
1282 VIRTIO_BLK_AUTO_NUM_QUEUES),
1283 DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 256),
1284 DEFINE_PROP_BOOL("seg-max-adjust", VirtIOBlock, conf.seg_max_adjust, true),
1285 DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD,
1286 IOThread *),
1287 DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features,
1288 VIRTIO_BLK_F_DISCARD, true),
1289 DEFINE_PROP_BOOL("report-discard-granularity", VirtIOBlock,
1290 conf.report_discard_granularity, true),
1291 DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock, host_features,
1292 VIRTIO_BLK_F_WRITE_ZEROES, true),
1293 DEFINE_PROP_UINT32("max-discard-sectors", VirtIOBlock,
1294 conf.max_discard_sectors, BDRV_REQUEST_MAX_SECTORS),
1295 DEFINE_PROP_UINT32("max-write-zeroes-sectors", VirtIOBlock,
1296 conf.max_write_zeroes_sectors, BDRV_REQUEST_MAX_SECTORS),
1297 DEFINE_PROP_BOOL("x-enable-wce-if-config-wce", VirtIOBlock,
1298 conf.x_enable_wce_if_config_wce, true),
1299 DEFINE_PROP_END_OF_LIST(),
1300};
1301
1302static void virtio_blk_class_init(ObjectClass *klass, void *data)
1303{
1304 DeviceClass *dc = DEVICE_CLASS(klass);
1305 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1306
1307 device_class_set_props(dc, virtio_blk_properties);
1308 dc->vmsd = &vmstate_virtio_blk;
1309 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1310 vdc->realize = virtio_blk_device_realize;
1311 vdc->unrealize = virtio_blk_device_unrealize;
1312 vdc->get_config = virtio_blk_update_config;
1313 vdc->set_config = virtio_blk_set_config;
1314 vdc->get_features = virtio_blk_get_features;
1315 vdc->set_status = virtio_blk_set_status;
1316 vdc->reset = virtio_blk_reset;
1317 vdc->save = virtio_blk_save_device;
1318 vdc->load = virtio_blk_load_device;
1319 vdc->start_ioeventfd = virtio_blk_data_plane_start;
1320 vdc->stop_ioeventfd = virtio_blk_data_plane_stop;
1321}
1322
1323static const TypeInfo virtio_blk_info = {
1324 .name = TYPE_VIRTIO_BLK,
1325 .parent = TYPE_VIRTIO_DEVICE,
1326 .instance_size = sizeof(VirtIOBlock),
1327 .instance_init = virtio_blk_instance_init,
1328 .class_init = virtio_blk_class_init,
1329};
1330
1331static void virtio_register_types(void)
1332{
1333 type_register_static(&virtio_blk_info);
1334}
1335
1336type_init(virtio_register_types)
1337