1/*
2 * Virtio Block Device
3 *
4 * Copyright IBM, Corp. 2007
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
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 "trace.h"
20#include "hw/block/block.h"
21#include "hw/qdev-properties.h"
22#include "sysemu/blockdev.h"
23#include "sysemu/sysemu.h"
24#include "sysemu/runstate.h"
25#include "hw/virtio/virtio-blk.h"
26#include "dataplane/virtio-blk.h"
27#include "scsi/constants.h"
28#ifdef __linux__
29# include <scsi/sg.h>
30#endif
31#include "hw/virtio/virtio-bus.h"
32#include "migration/qemu-file-types.h"
33#include "hw/virtio/virtio-access.h"
34
35/* Config size before the discard support (hide associated config fields) */
36#define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \
37 max_discard_sectors)
38/*
39 * Starting from the discard feature, we can use this array to properly
40 * set the config size depending on the features enabled.
41 */
42static VirtIOFeature feature_sizes[] = {
43 {.flags = 1ULL << VIRTIO_BLK_F_DISCARD,
44 .end = virtio_endof(struct virtio_blk_config, discard_sector_alignment)},
45 {.flags = 1ULL << VIRTIO_BLK_F_WRITE_ZEROES,
46 .end = virtio_endof(struct virtio_blk_config, write_zeroes_may_unmap)},
47 {}
48};
49
50static void virtio_blk_set_config_size(VirtIOBlock *s, uint64_t host_features)
51{
52 s->config_size = MAX(VIRTIO_BLK_CFG_SIZE,
53 virtio_feature_get_config_size(feature_sizes, host_features));
54
55 assert(s->config_size <= sizeof(struct virtio_blk_config));
56}
57
58static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
59 VirtIOBlockReq *req)
60{
61 req->dev = s;
62 req->vq = vq;
63 req->qiov.size = 0;
64 req->in_len = 0;
65 req->next = NULL;
66 req->mr_next = NULL;
67}
68
69static void virtio_blk_free_request(VirtIOBlockReq *req)
70{
71 g_free(req);
72}
73
74static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status)
75{
76 VirtIOBlock *s = req->dev;
77 VirtIODevice *vdev = VIRTIO_DEVICE(s);
78
79 trace_virtio_blk_req_complete(vdev, req, status);
80
81 stb_p(&req->in->status, status);
82 virtqueue_push(req->vq, &req->elem, req->in_len);
83 if (s->dataplane_started && !s->dataplane_disabled) {
84 virtio_blk_data_plane_notify(s->dataplane, req->vq);
85 } else {
86 virtio_notify(vdev, req->vq);
87 }
88}
89
90static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
91 bool is_read, bool acct_failed)
92{
93 VirtIOBlock *s = req->dev;
94 BlockErrorAction action = blk_get_error_action(s->blk, is_read, error);
95
96 if (action == BLOCK_ERROR_ACTION_STOP) {
97 /* Break the link as the next request is going to be parsed from the
98 * ring again. Otherwise we may end up doing a double completion! */
99 req->mr_next = NULL;
100 req->next = s->rq;
101 s->rq = req;
102 } else if (action == BLOCK_ERROR_ACTION_REPORT) {
103 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
104 if (acct_failed) {
105 block_acct_failed(blk_get_stats(s->blk), &req->acct);
106 }
107 virtio_blk_free_request(req);
108 }
109
110 blk_error_action(s->blk, action, is_read, error);
111 return action != BLOCK_ERROR_ACTION_IGNORE;
112}
113
114static void virtio_blk_rw_complete(void *opaque, int ret)
115{
116 VirtIOBlockReq *next = opaque;
117 VirtIOBlock *s = next->dev;
118 VirtIODevice *vdev = VIRTIO_DEVICE(s);
119
120 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
121 while (next) {
122 VirtIOBlockReq *req = next;
123 next = req->mr_next;
124 trace_virtio_blk_rw_complete(vdev, req, ret);
125
126 if (req->qiov.nalloc != -1) {
127 /* If nalloc is != -1 req->qiov is a local copy of the original
128 * external iovec. It was allocated in submit_requests to be
129 * able to merge requests. */
130 qemu_iovec_destroy(&req->qiov);
131 }
132
133 if (ret) {
134 int p = virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type);
135 bool is_read = !(p & VIRTIO_BLK_T_OUT);
136 /* Note that memory may be dirtied on read failure. If the
137 * virtio request is not completed here, as is the case for
138 * BLOCK_ERROR_ACTION_STOP, the memory may not be copied
139 * correctly during live migration. While this is ugly,
140 * it is acceptable because the device is free to write to
141 * the memory until the request is completed (which will
142 * happen on the other side of the migration).
143 */
144 if (virtio_blk_handle_rw_error(req, -ret, is_read, true)) {
145 continue;
146 }
147 }
148
149 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
150 block_acct_done(blk_get_stats(s->blk), &req->acct);
151 virtio_blk_free_request(req);
152 }
153 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
154}
155
156static void virtio_blk_flush_complete(void *opaque, int ret)
157{
158 VirtIOBlockReq *req = opaque;
159 VirtIOBlock *s = req->dev;
160
161 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
162 if (ret) {
163 if (virtio_blk_handle_rw_error(req, -ret, 0, true)) {
164 goto out;
165 }
166 }
167
168 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
169 block_acct_done(blk_get_stats(s->blk), &req->acct);
170 virtio_blk_free_request(req);
171
172out:
173 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
174}
175
176static void virtio_blk_discard_write_zeroes_complete(void *opaque, int ret)
177{
178 VirtIOBlockReq *req = opaque;
179 VirtIOBlock *s = req->dev;
180 bool is_write_zeroes = (virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type) &
181 ~VIRTIO_BLK_T_BARRIER) == VIRTIO_BLK_T_WRITE_ZEROES;
182
183 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
184 if (ret) {
185 if (virtio_blk_handle_rw_error(req, -ret, false, is_write_zeroes)) {
186 goto out;
187 }
188 }
189
190 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
191 if (is_write_zeroes) {
192 block_acct_done(blk_get_stats(s->blk), &req->acct);
193 }
194 virtio_blk_free_request(req);
195
196out:
197 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
198}
199
200#ifdef __linux__
201
202typedef struct {
203 VirtIOBlockReq *req;
204 struct sg_io_hdr hdr;
205} VirtIOBlockIoctlReq;
206
207static void virtio_blk_ioctl_complete(void *opaque, int status)
208{
209 VirtIOBlockIoctlReq *ioctl_req = opaque;
210 VirtIOBlockReq *req = ioctl_req->req;
211 VirtIOBlock *s = req->dev;
212 VirtIODevice *vdev = VIRTIO_DEVICE(s);
213 struct virtio_scsi_inhdr *scsi;
214 struct sg_io_hdr *hdr;
215
216 scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base;
217
218 if (status) {
219 status = VIRTIO_BLK_S_UNSUPP;
220 virtio_stl_p(vdev, &scsi->errors, 255);
221 goto out;
222 }
223
224 hdr = &ioctl_req->hdr;
225 /*
226 * From SCSI-Generic-HOWTO: "Some lower level drivers (e.g. ide-scsi)
227 * clear the masked_status field [hence status gets cleared too, see
228 * block/scsi_ioctl.c] even when a CHECK_CONDITION or COMMAND_TERMINATED
229 * status has occurred. However they do set DRIVER_SENSE in driver_status
230 * field. Also a (sb_len_wr > 0) indicates there is a sense buffer.
231 */
232 if (hdr->status == 0 && hdr->sb_len_wr > 0) {
233 hdr->status = CHECK_CONDITION;
234 }
235
236 virtio_stl_p(vdev, &scsi->errors,
237 hdr->status | (hdr->msg_status << 8) |
238 (hdr->host_status << 16) | (hdr->driver_status << 24));
239 virtio_stl_p(vdev, &scsi->residual, hdr->resid);
240 virtio_stl_p(vdev, &scsi->sense_len, hdr->sb_len_wr);
241 virtio_stl_p(vdev, &scsi->data_len, hdr->dxfer_len);
242
243out:
244 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
245 virtio_blk_req_complete(req, status);
246 virtio_blk_free_request(req);
247 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
248 g_free(ioctl_req);
249}
250
251#endif
252
253static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s, VirtQueue *vq)
254{
255 VirtIOBlockReq *req = virtqueue_pop(vq, sizeof(VirtIOBlockReq));
256
257 if (req) {
258 virtio_blk_init_request(s, vq, req);
259 }
260 return req;
261}
262
263static int virtio_blk_handle_scsi_req(VirtIOBlockReq *req)
264{
265 int status = VIRTIO_BLK_S_OK;
266 struct virtio_scsi_inhdr *scsi = NULL;
267 VirtIOBlock *blk = req->dev;
268 VirtIODevice *vdev = VIRTIO_DEVICE(blk);
269 VirtQueueElement *elem = &req->elem;
270
271#ifdef __linux__
272 int i;
273 VirtIOBlockIoctlReq *ioctl_req;
274 BlockAIOCB *acb;
275#endif
276
277 /*
278 * We require at least one output segment each for the virtio_blk_outhdr
279 * and the SCSI command block.
280 *
281 * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr
282 * and the sense buffer pointer in the input segments.
283 */
284 if (elem->out_num < 2 || elem->in_num < 3) {
285 status = VIRTIO_BLK_S_IOERR;
286 goto fail;
287 }
288
289 /*
290 * The scsi inhdr is placed in the second-to-last input segment, just
291 * before the regular inhdr.
292 */
293 scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base;
294
295 if (!virtio_has_feature(blk->host_features, VIRTIO_BLK_F_SCSI)) {
296 status = VIRTIO_BLK_S_UNSUPP;
297 goto fail;
298 }
299
300 /*
301 * No support for bidirection commands yet.
302 */
303 if (elem->out_num > 2 && elem->in_num > 3) {
304 status = VIRTIO_BLK_S_UNSUPP;
305 goto fail;
306 }
307
308#ifdef __linux__
309 ioctl_req = g_new0(VirtIOBlockIoctlReq, 1);
310 ioctl_req->req = req;
311 ioctl_req->hdr.interface_id = 'S';
312 ioctl_req->hdr.cmd_len = elem->out_sg[1].iov_len;
313 ioctl_req->hdr.cmdp = elem->out_sg[1].iov_base;
314 ioctl_req->hdr.dxfer_len = 0;
315
316 if (elem->out_num > 2) {
317 /*
318 * If there are more than the minimally required 2 output segments
319 * there is write payload starting from the third iovec.
320 */
321 ioctl_req->hdr.dxfer_direction = SG_DXFER_TO_DEV;
322 ioctl_req->hdr.iovec_count = elem->out_num - 2;
323
324 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) {
325 ioctl_req->hdr.dxfer_len += elem->out_sg[i + 2].iov_len;
326 }
327
328 ioctl_req->hdr.dxferp = elem->out_sg + 2;
329
330 } else if (elem->in_num > 3) {
331 /*
332 * If we have more than 3 input segments the guest wants to actually
333 * read data.
334 */
335 ioctl_req->hdr.dxfer_direction = SG_DXFER_FROM_DEV;
336 ioctl_req->hdr.iovec_count = elem->in_num - 3;
337 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) {
338 ioctl_req->hdr.dxfer_len += elem->in_sg[i].iov_len;
339 }
340
341 ioctl_req->hdr.dxferp = elem->in_sg;
342 } else {
343 /*
344 * Some SCSI commands don't actually transfer any data.
345 */
346 ioctl_req->hdr.dxfer_direction = SG_DXFER_NONE;
347 }
348
349 ioctl_req->hdr.sbp = elem->in_sg[elem->in_num - 3].iov_base;
350 ioctl_req->hdr.mx_sb_len = elem->in_sg[elem->in_num - 3].iov_len;
351
352 acb = blk_aio_ioctl(blk->blk, SG_IO, &ioctl_req->hdr,
353 virtio_blk_ioctl_complete, ioctl_req);
354 if (!acb) {
355 g_free(ioctl_req);
356 status = VIRTIO_BLK_S_UNSUPP;
357 goto fail;
358 }
359 return -EINPROGRESS;
360#else
361 abort();
362#endif
363
364fail:
365 /* Just put anything nonzero so that the ioctl fails in the guest. */
366 if (scsi) {
367 virtio_stl_p(vdev, &scsi->errors, 255);
368 }
369 return status;
370}
371
372static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
373{
374 int status;
375
376 status = virtio_blk_handle_scsi_req(req);
377 if (status != -EINPROGRESS) {
378 virtio_blk_req_complete(req, status);
379 virtio_blk_free_request(req);
380 }
381}
382
383static inline void submit_requests(BlockBackend *blk, MultiReqBuffer *mrb,
384 int start, int num_reqs, int niov)
385{
386 QEMUIOVector *qiov = &mrb->reqs[start]->qiov;
387 int64_t sector_num = mrb->reqs[start]->sector_num;
388 bool is_write = mrb->is_write;
389
390 if (num_reqs > 1) {
391 int i;
392 struct iovec *tmp_iov = qiov->iov;
393 int tmp_niov = qiov->niov;
394
395 /* mrb->reqs[start]->qiov was initialized from external so we can't
396 * modify it here. We need to initialize it locally and then add the
397 * external iovecs. */
398 qemu_iovec_init(qiov, niov);
399
400 for (i = 0; i < tmp_niov; i++) {
401 qemu_iovec_add(qiov, tmp_iov[i].iov_base, tmp_iov[i].iov_len);
402 }
403
404 for (i = start + 1; i < start + num_reqs; i++) {
405 qemu_iovec_concat(qiov, &mrb->reqs[i]->qiov, 0,
406 mrb->reqs[i]->qiov.size);
407 mrb->reqs[i - 1]->mr_next = mrb->reqs[i];
408 }
409
410 trace_virtio_blk_submit_multireq(VIRTIO_DEVICE(mrb->reqs[start]->dev),
411 mrb, start, num_reqs,
412 sector_num << BDRV_SECTOR_BITS,
413 qiov->size, is_write);
414 block_acct_merge_done(blk_get_stats(blk),
415 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ,
416 num_reqs - 1);
417 }
418
419 if (is_write) {
420 blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0,
421 virtio_blk_rw_complete, mrb->reqs[start]);
422 } else {
423 blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0,
424 virtio_blk_rw_complete, mrb->reqs[start]);
425 }
426}
427
428static int multireq_compare(const void *a, const void *b)
429{
430 const VirtIOBlockReq *req1 = *(VirtIOBlockReq **)a,
431 *req2 = *(VirtIOBlockReq **)b;
432
433 /*
434 * Note that we can't simply subtract sector_num1 from sector_num2
435 * here as that could overflow the return value.
436 */
437 if (req1->sector_num > req2->sector_num) {
438 return 1;
439 } else if (req1->sector_num < req2->sector_num) {
440 return -1;
441 } else {
442 return 0;
443 }
444}
445
446static void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb)
447{
448 int i = 0, start = 0, num_reqs = 0, niov = 0, nb_sectors = 0;
449 uint32_t max_transfer;
450 int64_t sector_num = 0;
451
452 if (mrb->num_reqs == 1) {
453 submit_requests(blk, mrb, 0, 1, -1);
454 mrb->num_reqs = 0;
455 return;
456 }
457
458 max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk);
459
460 qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs),
461 &multireq_compare);
462
463 for (i = 0; i < mrb->num_reqs; i++) {
464 VirtIOBlockReq *req = mrb->reqs[i];
465 if (num_reqs > 0) {
466 /*
467 * NOTE: We cannot merge the requests in below situations:
468 * 1. requests are not sequential
469 * 2. merge would exceed maximum number of IOVs
470 * 3. merge would exceed maximum transfer length of backend device
471 */
472 if (sector_num + nb_sectors != req->sector_num ||
473 niov > blk_get_max_iov(blk) - req->qiov.niov ||
474 req->qiov.size > max_transfer ||
475 nb_sectors > (max_transfer -
476 req->qiov.size) / BDRV_SECTOR_SIZE) {
477 submit_requests(blk, mrb, start, num_reqs, niov);
478 num_reqs = 0;
479 }
480 }
481
482 if (num_reqs == 0) {
483 sector_num = req->sector_num;
484 nb_sectors = niov = 0;
485 start = i;
486 }
487
488 nb_sectors += req->qiov.size / BDRV_SECTOR_SIZE;
489 niov += req->qiov.niov;
490 num_reqs++;
491 }
492
493 submit_requests(blk, mrb, start, num_reqs, niov);
494 mrb->num_reqs = 0;
495}
496
497static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb)
498{
499 VirtIOBlock *s = req->dev;
500
501 block_acct_start(blk_get_stats(s->blk), &req->acct, 0,
502 BLOCK_ACCT_FLUSH);
503
504 /*
505 * Make sure all outstanding writes are posted to the backing device.
506 */
507 if (mrb->is_write && mrb->num_reqs > 0) {
508 virtio_blk_submit_multireq(s->blk, mrb);
509 }
510 blk_aio_flush(s->blk, virtio_blk_flush_complete, req);
511}
512
513static bool virtio_blk_sect_range_ok(VirtIOBlock *dev,
514 uint64_t sector, size_t size)
515{
516 uint64_t nb_sectors = size >> BDRV_SECTOR_BITS;
517 uint64_t total_sectors;
518
519 if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
520 return false;
521 }
522 if (sector & dev->sector_mask) {
523 return false;
524 }
525 if (size % dev->conf.conf.logical_block_size) {
526 return false;
527 }
528 blk_get_geometry(dev->blk, &total_sectors);
529 if (sector > total_sectors || nb_sectors > total_sectors - sector) {
530 return false;
531 }
532 return true;
533}
534
535static uint8_t virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq *req,
536 struct virtio_blk_discard_write_zeroes *dwz_hdr, bool is_write_zeroes)
537{
538 VirtIOBlock *s = req->dev;
539 VirtIODevice *vdev = VIRTIO_DEVICE(s);
540 uint64_t sector;
541 uint32_t num_sectors, flags, max_sectors;
542 uint8_t err_status;
543 int bytes;
544
545 sector = virtio_ldq_p(vdev, &dwz_hdr->sector);
546 num_sectors = virtio_ldl_p(vdev, &dwz_hdr->num_sectors);
547 flags = virtio_ldl_p(vdev, &dwz_hdr->flags);
548 max_sectors = is_write_zeroes ? s->conf.max_write_zeroes_sectors :
549 s->conf.max_discard_sectors;
550
551 /*
552 * max_sectors is at most BDRV_REQUEST_MAX_SECTORS, this check
553 * make us sure that "num_sectors << BDRV_SECTOR_BITS" can fit in
554 * the integer variable.
555 */
556 if (unlikely(num_sectors > max_sectors)) {
557 err_status = VIRTIO_BLK_S_IOERR;
558 goto err;
559 }
560
561 bytes = num_sectors << BDRV_SECTOR_BITS;
562
563 if (unlikely(!virtio_blk_sect_range_ok(s, sector, bytes))) {
564 err_status = VIRTIO_BLK_S_IOERR;
565 goto err;
566 }
567
568 /*
569 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard
570 * and write zeroes commands if any unknown flag is set.
571 */
572 if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
573 err_status = VIRTIO_BLK_S_UNSUPP;
574 goto err;
575 }
576
577 if (is_write_zeroes) { /* VIRTIO_BLK_T_WRITE_ZEROES */
578 int blk_aio_flags = 0;
579
580 if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) {
581 blk_aio_flags |= BDRV_REQ_MAY_UNMAP;
582 }
583
584 block_acct_start(blk_get_stats(s->blk), &req->acct, bytes,
585 BLOCK_ACCT_WRITE);
586
587 blk_aio_pwrite_zeroes(s->blk, sector << BDRV_SECTOR_BITS,
588 bytes, blk_aio_flags,
589 virtio_blk_discard_write_zeroes_complete, req);
590 } else { /* VIRTIO_BLK_T_DISCARD */
591 /*
592 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for
593 * discard commands if the unmap flag is set.
594 */
595 if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
596 err_status = VIRTIO_BLK_S_UNSUPP;
597 goto err;
598 }
599
600 blk_aio_pdiscard(s->blk, sector << BDRV_SECTOR_BITS, bytes,
601 virtio_blk_discard_write_zeroes_complete, req);
602 }
603
604 return VIRTIO_BLK_S_OK;
605
606err:
607 if (is_write_zeroes) {
608 block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_WRITE);
609 }
610 return err_status;
611}
612
613static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
614{
615 uint32_t type;
616 struct iovec *in_iov = req->elem.in_sg;
617 struct iovec *out_iov = req->elem.out_sg;
618 unsigned in_num = req->elem.in_num;
619 unsigned out_num = req->elem.out_num;
620 VirtIOBlock *s = req->dev;
621 VirtIODevice *vdev = VIRTIO_DEVICE(s);
622
623 if (req->elem.out_num < 1 || req->elem.in_num < 1) {
624 virtio_error(vdev, "virtio-blk missing headers");
625 return -1;
626 }
627
628 if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
629 sizeof(req->out)) != sizeof(req->out))) {
630 virtio_error(vdev, "virtio-blk request outhdr too short");
631 return -1;
632 }
633
634 iov_discard_front(&out_iov, &out_num, sizeof(req->out));
635
636 if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
637 virtio_error(vdev, "virtio-blk request inhdr too short");
638 return -1;
639 }
640
641 /* We always touch the last byte, so just see how big in_iov is. */
642 req->in_len = iov_size(in_iov, in_num);
643 req->in = (void *)in_iov[in_num - 1].iov_base
644 + in_iov[in_num - 1].iov_len
645 - sizeof(struct virtio_blk_inhdr);
646 iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr));
647
648 type = virtio_ldl_p(vdev, &req->out.type);
649
650 /* VIRTIO_BLK_T_OUT defines the command direction. VIRTIO_BLK_T_BARRIER
651 * is an optional flag. Although a guest should not send this flag if
652 * not negotiated we ignored it in the past. So keep ignoring it. */
653 switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) {
654 case VIRTIO_BLK_T_IN:
655 {
656 bool is_write = type & VIRTIO_BLK_T_OUT;
657 req->sector_num = virtio_ldq_p(vdev, &req->out.sector);
658
659 if (is_write) {
660 qemu_iovec_init_external(&req->qiov, out_iov, out_num);
661 trace_virtio_blk_handle_write(vdev, req, req->sector_num,
662 req->qiov.size / BDRV_SECTOR_SIZE);
663 } else {
664 qemu_iovec_init_external(&req->qiov, in_iov, in_num);
665 trace_virtio_blk_handle_read(vdev, req, req->sector_num,
666 req->qiov.size / BDRV_SECTOR_SIZE);
667 }
668
669 if (!virtio_blk_sect_range_ok(s, req->sector_num, req->qiov.size)) {
670 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
671 block_acct_invalid(blk_get_stats(s->blk),
672 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
673 virtio_blk_free_request(req);
674 return 0;
675 }
676
677 block_acct_start(blk_get_stats(s->blk), &req->acct, req->qiov.size,
678 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
679
680 /* merge would exceed maximum number of requests or IO direction
681 * changes */
682 if (mrb->num_reqs > 0 && (mrb->num_reqs == VIRTIO_BLK_MAX_MERGE_REQS ||
683 is_write != mrb->is_write ||
684 !s->conf.request_merging)) {
685 virtio_blk_submit_multireq(s->blk, mrb);
686 }
687
688 assert(mrb->num_reqs < VIRTIO_BLK_MAX_MERGE_REQS);
689 mrb->reqs[mrb->num_reqs++] = req;
690 mrb->is_write = is_write;
691 break;
692 }
693 case VIRTIO_BLK_T_FLUSH:
694 virtio_blk_handle_flush(req, mrb);
695 break;
696 case VIRTIO_BLK_T_SCSI_CMD:
697 virtio_blk_handle_scsi(req);
698 break;
699 case VIRTIO_BLK_T_GET_ID:
700 {
701 /*
702 * NB: per existing s/n string convention the string is
703 * terminated by '\0' only when shorter than buffer.
704 */
705 const char *serial = s->conf.serial ? s->conf.serial : "";
706 size_t size = MIN(strlen(serial) + 1,
707 MIN(iov_size(in_iov, in_num),
708 VIRTIO_BLK_ID_BYTES));
709 iov_from_buf(in_iov, in_num, 0, serial, size);
710 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
711 virtio_blk_free_request(req);
712 break;
713 }
714 /*
715 * VIRTIO_BLK_T_DISCARD and VIRTIO_BLK_T_WRITE_ZEROES are defined with
716 * VIRTIO_BLK_T_OUT flag set. We masked this flag in the switch statement,
717 * so we must mask it for these requests, then we will check if it is set.
718 */
719 case VIRTIO_BLK_T_DISCARD & ~VIRTIO_BLK_T_OUT:
720 case VIRTIO_BLK_T_WRITE_ZEROES & ~VIRTIO_BLK_T_OUT:
721 {
722 struct virtio_blk_discard_write_zeroes dwz_hdr;
723 size_t out_len = iov_size(out_iov, out_num);
724 bool is_write_zeroes = (type & ~VIRTIO_BLK_T_BARRIER) ==
725 VIRTIO_BLK_T_WRITE_ZEROES;
726 uint8_t err_status;
727
728 /*
729 * Unsupported if VIRTIO_BLK_T_OUT is not set or the request contains
730 * more than one segment.
731 */
732 if (unlikely(!(type & VIRTIO_BLK_T_OUT) ||
733 out_len > sizeof(dwz_hdr))) {
734 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
735 virtio_blk_free_request(req);
736 return 0;
737 }
738
739 if (unlikely(iov_to_buf(out_iov, out_num, 0, &dwz_hdr,
740 sizeof(dwz_hdr)) != sizeof(dwz_hdr))) {
741 virtio_error(vdev, "virtio-blk discard/write_zeroes header"
742 " too short");
743 return -1;
744 }
745
746 err_status = virtio_blk_handle_discard_write_zeroes(req, &dwz_hdr,
747 is_write_zeroes);
748 if (err_status != VIRTIO_BLK_S_OK) {
749 virtio_blk_req_complete(req, err_status);
750 virtio_blk_free_request(req);
751 }
752
753 break;
754 }
755 default:
756 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
757 virtio_blk_free_request(req);
758 }
759 return 0;
760}
761
762bool virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq)
763{
764 VirtIOBlockReq *req;
765 MultiReqBuffer mrb = {};
766 bool progress = false;
767
768 aio_context_acquire(blk_get_aio_context(s->blk));
769 blk_io_plug(s->blk);
770
771 do {
772 virtio_queue_set_notification(vq, 0);
773
774 while ((req = virtio_blk_get_request(s, vq))) {
775 progress = true;
776 if (virtio_blk_handle_request(req, &mrb)) {
777 virtqueue_detach_element(req->vq, &req->elem, 0);
778 virtio_blk_free_request(req);
779 break;
780 }
781 }
782
783 virtio_queue_set_notification(vq, 1);
784 } while (!virtio_queue_empty(vq));
785
786 if (mrb.num_reqs) {
787 virtio_blk_submit_multireq(s->blk, &mrb);
788 }
789
790 blk_io_unplug(s->blk);
791 aio_context_release(blk_get_aio_context(s->blk));
792 return progress;
793}
794
795static void virtio_blk_handle_output_do(VirtIOBlock *s, VirtQueue *vq)
796{
797 virtio_blk_handle_vq(s, vq);
798}
799
800static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
801{
802 VirtIOBlock *s = (VirtIOBlock *)vdev;
803
804 if (s->dataplane) {
805 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
806 * dataplane here instead of waiting for .set_status().
807 */
808 virtio_device_start_ioeventfd(vdev);
809 if (!s->dataplane_disabled) {
810 return;
811 }
812 }
813 virtio_blk_handle_output_do(s, vq);
814}
815
816static void virtio_blk_dma_restart_bh(void *opaque)
817{
818 VirtIOBlock *s = opaque;
819 VirtIOBlockReq *req = s->rq;
820 MultiReqBuffer mrb = {};
821
822 qemu_bh_delete(s->bh);
823 s->bh = NULL;
824
825 s->rq = NULL;
826
827 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
828 while (req) {
829 VirtIOBlockReq *next = req->next;
830 if (virtio_blk_handle_request(req, &mrb)) {
831 /* Device is now broken and won't do any processing until it gets
832 * reset. Already queued requests will be lost: let's purge them.
833 */
834 while (req) {
835 next = req->next;
836 virtqueue_detach_element(req->vq, &req->elem, 0);
837 virtio_blk_free_request(req);
838 req = next;
839 }
840 break;
841 }
842 req = next;
843 }
844
845 if (mrb.num_reqs) {
846 virtio_blk_submit_multireq(s->blk, &mrb);
847 }
848 blk_dec_in_flight(s->conf.conf.blk);
849 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
850}
851
852static void virtio_blk_dma_restart_cb(void *opaque, int running,
853 RunState state)
854{
855 VirtIOBlock *s = opaque;
856
857 if (!running) {
858 return;
859 }
860
861 if (!s->bh) {
862 /* FIXME The data plane is not started yet, so these requests are
863 * processed in the main thread. */
864 s->bh = aio_bh_new(blk_get_aio_context(s->conf.conf.blk),
865 virtio_blk_dma_restart_bh, s);
866 blk_inc_in_flight(s->conf.conf.blk);
867 qemu_bh_schedule(s->bh);
868 }
869}
870
871static void virtio_blk_reset(VirtIODevice *vdev)
872{
873 VirtIOBlock *s = VIRTIO_BLK(vdev);
874 AioContext *ctx;
875 VirtIOBlockReq *req;
876
877 ctx = blk_get_aio_context(s->blk);
878 aio_context_acquire(ctx);
879 blk_drain(s->blk);
880
881 /* We drop queued requests after blk_drain() because blk_drain() itself can
882 * produce them. */
883 while (s->rq) {
884 req = s->rq;
885 s->rq = req->next;
886 virtqueue_detach_element(req->vq, &req->elem, 0);
887 virtio_blk_free_request(req);
888 }
889
890 aio_context_release(ctx);
891
892 assert(!s->dataplane_started);
893 blk_set_enable_write_cache(s->blk, s->original_wce);
894}
895
896/* coalesce internal state, copy to pci i/o region 0
897 */
898static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
899{
900 VirtIOBlock *s = VIRTIO_BLK(vdev);
901 BlockConf *conf = &s->conf.conf;
902 struct virtio_blk_config blkcfg;
903 uint64_t capacity;
904 int64_t length;
905 int blk_size = conf->logical_block_size;
906
907 blk_get_geometry(s->blk, &capacity);
908 memset(&blkcfg, 0, sizeof(blkcfg));
909 virtio_stq_p(vdev, &blkcfg.capacity, capacity);
910 virtio_stl_p(vdev, &blkcfg.seg_max, 128 - 2);
911 virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls);
912 virtio_stl_p(vdev, &blkcfg.blk_size, blk_size);
913 virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size);
914 virtio_stw_p(vdev, &blkcfg.opt_io_size, conf->opt_io_size / blk_size);
915 blkcfg.geometry.heads = conf->heads;
916 /*
917 * We must ensure that the block device capacity is a multiple of
918 * the logical block size. If that is not the case, let's use
919 * sector_mask to adopt the geometry to have a correct picture.
920 * For those devices where the capacity is ok for the given geometry
921 * we don't touch the sector value of the geometry, since some devices
922 * (like s390 dasd) need a specific value. Here the capacity is already
923 * cyls*heads*secs*blk_size and the sector value is not block size
924 * divided by 512 - instead it is the amount of blk_size blocks
925 * per track (cylinder).
926 */
927 length = blk_getlength(s->blk);
928 if (length > 0 && length / conf->heads / conf->secs % blk_size) {
929 blkcfg.geometry.sectors = conf->secs & ~s->sector_mask;
930 } else {
931 blkcfg.geometry.sectors = conf->secs;
932 }
933 blkcfg.size_max = 0;
934 blkcfg.physical_block_exp = get_physical_block_exp(conf);
935 blkcfg.alignment_offset = 0;
936 blkcfg.wce = blk_enable_write_cache(s->blk);
937 virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues);
938 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD)) {
939 virtio_stl_p(vdev, &blkcfg.max_discard_sectors,
940 s->conf.max_discard_sectors);
941 virtio_stl_p(vdev, &blkcfg.discard_sector_alignment,
942 blk_size >> BDRV_SECTOR_BITS);
943 /*
944 * We support only one segment per request since multiple segments
945 * are not widely used and there are no userspace APIs that allow
946 * applications to submit multiple segments in a single call.
947 */
948 virtio_stl_p(vdev, &blkcfg.max_discard_seg, 1);
949 }
950 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES)) {
951 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_sectors,
952 s->conf.max_write_zeroes_sectors);
953 blkcfg.write_zeroes_may_unmap = 1;
954 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_seg, 1);
955 }
956 memcpy(config, &blkcfg, s->config_size);
957}
958
959static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
960{
961 VirtIOBlock *s = VIRTIO_BLK(vdev);
962 struct virtio_blk_config blkcfg;
963
964 memcpy(&blkcfg, config, s->config_size);
965
966 aio_context_acquire(blk_get_aio_context(s->blk));
967 blk_set_enable_write_cache(s->blk, blkcfg.wce != 0);
968 aio_context_release(blk_get_aio_context(s->blk));
969}
970
971static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features,
972 Error **errp)
973{
974 VirtIOBlock *s = VIRTIO_BLK(vdev);
975
976 /* Firstly sync all virtio-blk possible supported features */
977 features |= s->host_features;
978
979 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
980 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
981 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
982 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
983 if (virtio_has_feature(features, VIRTIO_F_VERSION_1)) {
984 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_SCSI)) {
985 error_setg(errp, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0");
986 return 0;
987 }
988 } else {
989 virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT);
990 virtio_add_feature(&features, VIRTIO_BLK_F_SCSI);
991 }
992
993 if (blk_enable_write_cache(s->blk)) {
994 virtio_add_feature(&features, VIRTIO_BLK_F_WCE);
995 }
996 if (blk_is_read_only(s->blk)) {
997 virtio_add_feature(&features, VIRTIO_BLK_F_RO);
998 }
999 if (s->conf.num_queues > 1) {
1000 virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
1001 }
1002
1003 return features;
1004}
1005
1006static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
1007{
1008 VirtIOBlock *s = VIRTIO_BLK(vdev);
1009
1010 if (!(status & (VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK))) {
1011 assert(!s->dataplane_started);
1012 }
1013
1014 if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
1015 return;
1016 }
1017
1018 /* A guest that supports VIRTIO_BLK_F_CONFIG_WCE must be able to send
1019 * cache flushes. Thus, the "auto writethrough" behavior is never
1020 * necessary for guests that support the VIRTIO_BLK_F_CONFIG_WCE feature.
1021 * Leaving it enabled would break the following sequence:
1022 *
1023 * Guest started with "-drive cache=writethrough"
1024 * Guest sets status to 0
1025 * Guest sets DRIVER bit in status field
1026 * Guest reads host features (WCE=0, CONFIG_WCE=1)
1027 * Guest writes guest features (WCE=0, CONFIG_WCE=1)
1028 * Guest writes 1 to the WCE configuration field (writeback mode)
1029 * Guest sets DRIVER_OK bit in status field
1030 *
1031 * s->blk would erroneously be placed in writethrough mode.
1032 */
1033 if (!virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) {
1034 aio_context_acquire(blk_get_aio_context(s->blk));
1035 blk_set_enable_write_cache(s->blk,
1036 virtio_vdev_has_feature(vdev,
1037 VIRTIO_BLK_F_WCE));
1038 aio_context_release(blk_get_aio_context(s->blk));
1039 }
1040}
1041
1042static void virtio_blk_save_device(VirtIODevice *vdev, QEMUFile *f)
1043{
1044 VirtIOBlock *s = VIRTIO_BLK(vdev);
1045 VirtIOBlockReq *req = s->rq;
1046
1047 while (req) {
1048 qemu_put_sbyte(f, 1);
1049
1050 if (s->conf.num_queues > 1) {
1051 qemu_put_be32(f, virtio_get_queue_index(req->vq));
1052 }
1053
1054 qemu_put_virtqueue_element(f, &req->elem);
1055 req = req->next;
1056 }
1057 qemu_put_sbyte(f, 0);
1058}
1059
1060static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f,
1061 int version_id)
1062{
1063 VirtIOBlock *s = VIRTIO_BLK(vdev);
1064
1065 while (qemu_get_sbyte(f)) {
1066 unsigned nvqs = s->conf.num_queues;
1067 unsigned vq_idx = 0;
1068 VirtIOBlockReq *req;
1069
1070 if (nvqs > 1) {
1071 vq_idx = qemu_get_be32(f);
1072
1073 if (vq_idx >= nvqs) {
1074 error_report("Invalid virtqueue index in request list: %#x",
1075 vq_idx);
1076 return -EINVAL;
1077 }
1078 }
1079
1080 req = qemu_get_virtqueue_element(vdev, f, sizeof(VirtIOBlockReq));
1081 virtio_blk_init_request(s, virtio_get_queue(vdev, vq_idx), req);
1082 req->next = s->rq;
1083 s->rq = req;
1084 }
1085
1086 return 0;
1087}
1088
1089static void virtio_blk_resize(void *opaque)
1090{
1091 VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
1092
1093 virtio_notify_config(vdev);
1094}
1095
1096static const BlockDevOps virtio_block_ops = {
1097 .resize_cb = virtio_blk_resize,
1098};
1099
1100static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
1101{
1102 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1103 VirtIOBlock *s = VIRTIO_BLK(dev);
1104 VirtIOBlkConf *conf = &s->conf;
1105 Error *err = NULL;
1106 unsigned i;
1107
1108 if (!conf->conf.blk) {
1109 error_setg(errp, "drive property not set");
1110 return;
1111 }
1112 if (!blk_is_inserted(conf->conf.blk)) {
1113 error_setg(errp, "Device needs media, but drive is empty");
1114 return;
1115 }
1116 if (!conf->num_queues) {
1117 error_setg(errp, "num-queues property must be larger than 0");
1118 return;
1119 }
1120 if (!is_power_of_2(conf->queue_size) ||
1121 conf->queue_size > VIRTQUEUE_MAX_SIZE) {
1122 error_setg(errp, "invalid queue-size property (%" PRIu16 "), "
1123 "must be a power of 2 (max %d)",
1124 conf->queue_size, VIRTQUEUE_MAX_SIZE);
1125 return;
1126 }
1127
1128 if (!blkconf_apply_backend_options(&conf->conf,
1129 blk_is_read_only(conf->conf.blk), true,
1130 errp)) {
1131 return;
1132 }
1133 s->original_wce = blk_enable_write_cache(conf->conf.blk);
1134 if (!blkconf_geometry(&conf->conf, NULL, 65535, 255, 255, errp)) {
1135 return;
1136 }
1137
1138 blkconf_blocksizes(&conf->conf);
1139
1140 if (conf->conf.logical_block_size >
1141 conf->conf.physical_block_size) {
1142 error_setg(errp,
1143 "logical_block_size > physical_block_size not supported");
1144 return;
1145 }
1146
1147 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD) &&
1148 (!conf->max_discard_sectors ||
1149 conf->max_discard_sectors > BDRV_REQUEST_MAX_SECTORS)) {
1150 error_setg(errp, "invalid max-discard-sectors property (%" PRIu32 ")"
1151 ", must be between 1 and %d",
1152 conf->max_discard_sectors, (int)BDRV_REQUEST_MAX_SECTORS);
1153 return;
1154 }
1155
1156 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES) &&
1157 (!conf->max_write_zeroes_sectors ||
1158 conf->max_write_zeroes_sectors > BDRV_REQUEST_MAX_SECTORS)) {
1159 error_setg(errp, "invalid max-write-zeroes-sectors property (%" PRIu32
1160 "), must be between 1 and %d",
1161 conf->max_write_zeroes_sectors,
1162 (int)BDRV_REQUEST_MAX_SECTORS);
1163 return;
1164 }
1165
1166 virtio_blk_set_config_size(s, s->host_features);
1167
1168 virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, s->config_size);
1169
1170 s->blk = conf->conf.blk;
1171 s->rq = NULL;
1172 s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1;
1173
1174 for (i = 0; i < conf->num_queues; i++) {
1175 virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output);
1176 }
1177 virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err);
1178 if (err != NULL) {
1179 error_propagate(errp, err);
1180 virtio_cleanup(vdev);
1181 return;
1182 }
1183
1184 s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
1185 blk_set_dev_ops(s->blk, &virtio_block_ops, s);
1186 blk_set_guest_block_size(s->blk, s->conf.conf.logical_block_size);
1187
1188 blk_iostatus_enable(s->blk);
1189}
1190
1191static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp)
1192{
1193 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1194 VirtIOBlock *s = VIRTIO_BLK(dev);
1195
1196 virtio_blk_data_plane_destroy(s->dataplane);
1197 s->dataplane = NULL;
1198 qemu_del_vm_change_state_handler(s->change);
1199 blockdev_mark_auto_del(s->blk);
1200 virtio_cleanup(vdev);
1201}
1202
1203static void virtio_blk_instance_init(Object *obj)
1204{
1205 VirtIOBlock *s = VIRTIO_BLK(obj);
1206
1207 device_add_bootindex_property(obj, &s->conf.conf.bootindex,
1208 "bootindex", "/disk@0,0",
1209 DEVICE(obj), NULL);
1210}
1211
1212static const VMStateDescription vmstate_virtio_blk = {
1213 .name = "virtio-blk",
1214 .minimum_version_id = 2,
1215 .version_id = 2,
1216 .fields = (VMStateField[]) {
1217 VMSTATE_VIRTIO_DEVICE,
1218 VMSTATE_END_OF_LIST()
1219 },
1220};
1221
1222static Property virtio_blk_properties[] = {
1223 DEFINE_BLOCK_PROPERTIES(VirtIOBlock, conf.conf),
1224 DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock, conf.conf),
1225 DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, conf.conf),
1226 DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial),
1227 DEFINE_PROP_BIT64("config-wce", VirtIOBlock, host_features,
1228 VIRTIO_BLK_F_CONFIG_WCE, true),
1229#ifdef __linux__
1230 DEFINE_PROP_BIT64("scsi", VirtIOBlock, host_features,
1231 VIRTIO_BLK_F_SCSI, false),
1232#endif
1233 DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0,
1234 true),
1235 DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues, 1),
1236 DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 128),
1237 DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD,
1238 IOThread *),
1239 DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features,
1240 VIRTIO_BLK_F_DISCARD, true),
1241 DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock, host_features,
1242 VIRTIO_BLK_F_WRITE_ZEROES, true),
1243 DEFINE_PROP_UINT32("max-discard-sectors", VirtIOBlock,
1244 conf.max_discard_sectors, BDRV_REQUEST_MAX_SECTORS),
1245 DEFINE_PROP_UINT32("max-write-zeroes-sectors", VirtIOBlock,
1246 conf.max_write_zeroes_sectors, BDRV_REQUEST_MAX_SECTORS),
1247 DEFINE_PROP_END_OF_LIST(),
1248};
1249
1250static void virtio_blk_class_init(ObjectClass *klass, void *data)
1251{
1252 DeviceClass *dc = DEVICE_CLASS(klass);
1253 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1254
1255 dc->props = virtio_blk_properties;
1256 dc->vmsd = &vmstate_virtio_blk;
1257 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1258 vdc->realize = virtio_blk_device_realize;
1259 vdc->unrealize = virtio_blk_device_unrealize;
1260 vdc->get_config = virtio_blk_update_config;
1261 vdc->set_config = virtio_blk_set_config;
1262 vdc->get_features = virtio_blk_get_features;
1263 vdc->set_status = virtio_blk_set_status;
1264 vdc->reset = virtio_blk_reset;
1265 vdc->save = virtio_blk_save_device;
1266 vdc->load = virtio_blk_load_device;
1267 vdc->start_ioeventfd = virtio_blk_data_plane_start;
1268 vdc->stop_ioeventfd = virtio_blk_data_plane_stop;
1269}
1270
1271static const TypeInfo virtio_blk_info = {
1272 .name = TYPE_VIRTIO_BLK,
1273 .parent = TYPE_VIRTIO_DEVICE,
1274 .instance_size = sizeof(VirtIOBlock),
1275 .instance_init = virtio_blk_instance_init,
1276 .class_init = virtio_blk_class_init,
1277};
1278
1279static void virtio_register_types(void)
1280{
1281 type_register_static(&virtio_blk_info);
1282}
1283
1284type_init(virtio_register_types)
1285