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 "qemu/defer-call.h"
16 #include "qapi/error.h"
17 #include "qemu/iov.h"
18 #include "qemu/module.h"
19 #include "qemu/error-report.h"
20 #include "qemu/main-loop.h"
21 #include "block/block_int.h"
22 #include "trace.h"
23 #include "hw/block/block.h"
24 #include "hw/qdev-properties.h"
25 #include "sysemu/blockdev.h"
26 #include "sysemu/block-ram-registrar.h"
27 #include "sysemu/sysemu.h"
28 #include "sysemu/runstate.h"
29 #include "hw/virtio/virtio-blk.h"
30 #include "scsi/constants.h"
31 #ifdef __linux__
32 # include <scsi/sg.h>
33 #endif
34 #include "hw/virtio/virtio-bus.h"
35 #include "migration/qemu-file-types.h"
36 #include "hw/virtio/virtio-access.h"
37 #include "hw/virtio/virtio-blk-common.h"
38 #include "qemu/coroutine.h"
39
40 static void virtio_blk_ioeventfd_attach(VirtIOBlock *s);
41
virtio_blk_init_request(VirtIOBlock * s,VirtQueue * vq,VirtIOBlockReq * req)42 static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
43 VirtIOBlockReq *req)
44 {
45 req->dev = s;
46 req->vq = vq;
47 req->qiov.size = 0;
48 req->in_len = 0;
49 req->next = NULL;
50 req->mr_next = NULL;
51 }
52
virtio_blk_free_request(VirtIOBlockReq * req)53 static void virtio_blk_free_request(VirtIOBlockReq *req)
54 {
55 g_free(req);
56 }
57
virtio_blk_req_complete(VirtIOBlockReq * req,unsigned char status)58 static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status)
59 {
60 VirtIOBlock *s = req->dev;
61 VirtIODevice *vdev = VIRTIO_DEVICE(s);
62
63 trace_virtio_blk_req_complete(vdev, req, status);
64
65 stb_p(&req->in->status, status);
66 iov_discard_undo(&req->inhdr_undo);
67 iov_discard_undo(&req->outhdr_undo);
68 virtqueue_push(req->vq, &req->elem, req->in_len);
69 if (qemu_in_iothread()) {
70 virtio_notify_irqfd(vdev, req->vq);
71 } else {
72 virtio_notify(vdev, req->vq);
73 }
74 }
75
virtio_blk_handle_rw_error(VirtIOBlockReq * req,int error,bool is_read,bool acct_failed)76 static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
77 bool is_read, bool acct_failed)
78 {
79 VirtIOBlock *s = req->dev;
80 BlockErrorAction action = blk_get_error_action(s->blk, is_read, error);
81
82 if (action == BLOCK_ERROR_ACTION_STOP) {
83 /* Break the link as the next request is going to be parsed from the
84 * ring again. Otherwise we may end up doing a double completion! */
85 req->mr_next = NULL;
86
87 WITH_QEMU_LOCK_GUARD(&s->rq_lock) {
88 req->next = s->rq;
89 s->rq = req;
90 }
91 } else if (action == BLOCK_ERROR_ACTION_REPORT) {
92 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
93 if (acct_failed) {
94 block_acct_failed(blk_get_stats(s->blk), &req->acct);
95 }
96 virtio_blk_free_request(req);
97 }
98
99 blk_error_action(s->blk, action, is_read, error);
100 return action != BLOCK_ERROR_ACTION_IGNORE;
101 }
102
virtio_blk_rw_complete(void * opaque,int ret)103 static void virtio_blk_rw_complete(void *opaque, int ret)
104 {
105 VirtIOBlockReq *next = opaque;
106 VirtIOBlock *s = next->dev;
107 VirtIODevice *vdev = VIRTIO_DEVICE(s);
108
109 while (next) {
110 VirtIOBlockReq *req = next;
111 next = req->mr_next;
112 trace_virtio_blk_rw_complete(vdev, req, ret);
113
114 if (req->qiov.nalloc != -1) {
115 /* If nalloc is != -1 req->qiov is a local copy of the original
116 * external iovec. It was allocated in submit_requests to be
117 * able to merge requests. */
118 qemu_iovec_destroy(&req->qiov);
119 }
120
121 if (ret) {
122 int p = virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type);
123 bool is_read = !(p & VIRTIO_BLK_T_OUT);
124 /* Note that memory may be dirtied on read failure. If the
125 * virtio request is not completed here, as is the case for
126 * BLOCK_ERROR_ACTION_STOP, the memory may not be copied
127 * correctly during live migration. While this is ugly,
128 * it is acceptable because the device is free to write to
129 * the memory until the request is completed (which will
130 * happen on the other side of the migration).
131 */
132 if (virtio_blk_handle_rw_error(req, -ret, is_read, true)) {
133 continue;
134 }
135 }
136
137 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
138 block_acct_done(blk_get_stats(s->blk), &req->acct);
139 virtio_blk_free_request(req);
140 }
141 }
142
virtio_blk_flush_complete(void * opaque,int ret)143 static void virtio_blk_flush_complete(void *opaque, int ret)
144 {
145 VirtIOBlockReq *req = opaque;
146 VirtIOBlock *s = req->dev;
147
148 if (ret && virtio_blk_handle_rw_error(req, -ret, 0, true)) {
149 return;
150 }
151
152 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
153 block_acct_done(blk_get_stats(s->blk), &req->acct);
154 virtio_blk_free_request(req);
155 }
156
virtio_blk_discard_write_zeroes_complete(void * opaque,int ret)157 static void virtio_blk_discard_write_zeroes_complete(void *opaque, int ret)
158 {
159 VirtIOBlockReq *req = opaque;
160 VirtIOBlock *s = req->dev;
161 bool is_write_zeroes = (virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type) &
162 ~VIRTIO_BLK_T_BARRIER) == VIRTIO_BLK_T_WRITE_ZEROES;
163
164 if (ret && virtio_blk_handle_rw_error(req, -ret, false, is_write_zeroes)) {
165 return;
166 }
167
168 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
169 if (is_write_zeroes) {
170 block_acct_done(blk_get_stats(s->blk), &req->acct);
171 }
172 virtio_blk_free_request(req);
173 }
174
virtio_blk_get_request(VirtIOBlock * s,VirtQueue * vq)175 static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s, VirtQueue *vq)
176 {
177 VirtIOBlockReq *req = virtqueue_pop(vq, sizeof(VirtIOBlockReq));
178
179 if (req) {
180 virtio_blk_init_request(s, vq, req);
181 }
182 return req;
183 }
184
virtio_blk_handle_scsi(VirtIOBlockReq * req)185 static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
186 {
187 int status;
188 struct virtio_scsi_inhdr *scsi;
189 VirtIOBlock *blk = req->dev;
190 VirtIODevice *vdev = VIRTIO_DEVICE(blk);
191 VirtQueueElement *elem = &req->elem;
192
193 /*
194 * We require at least one output segment each for the virtio_blk_outhdr
195 * and the SCSI command block.
196 *
197 * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr
198 * and the sense buffer pointer in the input segments.
199 */
200 if (elem->out_num < 2 || elem->in_num < 3) {
201 status = VIRTIO_BLK_S_IOERR;
202 goto fail;
203 }
204
205 /*
206 * The scsi inhdr is placed in the second-to-last input segment, just
207 * before the regular inhdr.
208 *
209 * Just put anything nonzero so that the ioctl fails in the guest.
210 */
211 scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base;
212 virtio_stl_p(vdev, &scsi->errors, 255);
213 status = VIRTIO_BLK_S_UNSUPP;
214
215 fail:
216 virtio_blk_req_complete(req, status);
217 virtio_blk_free_request(req);
218 }
219
submit_requests(VirtIOBlock * s,MultiReqBuffer * mrb,int start,int num_reqs,int niov)220 static inline void submit_requests(VirtIOBlock *s, MultiReqBuffer *mrb,
221 int start, int num_reqs, int niov)
222 {
223 BlockBackend *blk = s->blk;
224 QEMUIOVector *qiov = &mrb->reqs[start]->qiov;
225 int64_t sector_num = mrb->reqs[start]->sector_num;
226 bool is_write = mrb->is_write;
227 BdrvRequestFlags flags = 0;
228
229 if (num_reqs > 1) {
230 int i;
231 struct iovec *tmp_iov = qiov->iov;
232 int tmp_niov = qiov->niov;
233
234 /* mrb->reqs[start]->qiov was initialized from external so we can't
235 * modify it here. We need to initialize it locally and then add the
236 * external iovecs. */
237 qemu_iovec_init(qiov, niov);
238
239 for (i = 0; i < tmp_niov; i++) {
240 qemu_iovec_add(qiov, tmp_iov[i].iov_base, tmp_iov[i].iov_len);
241 }
242
243 for (i = start + 1; i < start + num_reqs; i++) {
244 qemu_iovec_concat(qiov, &mrb->reqs[i]->qiov, 0,
245 mrb->reqs[i]->qiov.size);
246 mrb->reqs[i - 1]->mr_next = mrb->reqs[i];
247 }
248
249 trace_virtio_blk_submit_multireq(VIRTIO_DEVICE(mrb->reqs[start]->dev),
250 mrb, start, num_reqs,
251 sector_num << BDRV_SECTOR_BITS,
252 qiov->size, is_write);
253 block_acct_merge_done(blk_get_stats(blk),
254 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ,
255 num_reqs - 1);
256 }
257
258 if (blk_ram_registrar_ok(&s->blk_ram_registrar)) {
259 flags |= BDRV_REQ_REGISTERED_BUF;
260 }
261
262 if (is_write) {
263 blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov,
264 flags, virtio_blk_rw_complete,
265 mrb->reqs[start]);
266 } else {
267 blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov,
268 flags, virtio_blk_rw_complete,
269 mrb->reqs[start]);
270 }
271 }
272
multireq_compare(const void * a,const void * b)273 static int multireq_compare(const void *a, const void *b)
274 {
275 const VirtIOBlockReq *req1 = *(VirtIOBlockReq **)a,
276 *req2 = *(VirtIOBlockReq **)b;
277
278 /*
279 * Note that we can't simply subtract sector_num1 from sector_num2
280 * here as that could overflow the return value.
281 */
282 if (req1->sector_num > req2->sector_num) {
283 return 1;
284 } else if (req1->sector_num < req2->sector_num) {
285 return -1;
286 } else {
287 return 0;
288 }
289 }
290
virtio_blk_submit_multireq(VirtIOBlock * s,MultiReqBuffer * mrb)291 static void virtio_blk_submit_multireq(VirtIOBlock *s, MultiReqBuffer *mrb)
292 {
293 int i = 0, start = 0, num_reqs = 0, niov = 0, nb_sectors = 0;
294 uint32_t max_transfer;
295 int64_t sector_num = 0;
296
297 if (mrb->num_reqs == 1) {
298 submit_requests(s, mrb, 0, 1, -1);
299 mrb->num_reqs = 0;
300 return;
301 }
302
303 max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk);
304
305 qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs),
306 &multireq_compare);
307
308 for (i = 0; i < mrb->num_reqs; i++) {
309 VirtIOBlockReq *req = mrb->reqs[i];
310 if (num_reqs > 0) {
311 /*
312 * NOTE: We cannot merge the requests in below situations:
313 * 1. requests are not sequential
314 * 2. merge would exceed maximum number of IOVs
315 * 3. merge would exceed maximum transfer length of backend device
316 */
317 if (sector_num + nb_sectors != req->sector_num ||
318 niov > blk_get_max_iov(s->blk) - req->qiov.niov ||
319 req->qiov.size > max_transfer ||
320 nb_sectors > (max_transfer -
321 req->qiov.size) / BDRV_SECTOR_SIZE) {
322 submit_requests(s, mrb, start, num_reqs, niov);
323 num_reqs = 0;
324 }
325 }
326
327 if (num_reqs == 0) {
328 sector_num = req->sector_num;
329 nb_sectors = niov = 0;
330 start = i;
331 }
332
333 nb_sectors += req->qiov.size / BDRV_SECTOR_SIZE;
334 niov += req->qiov.niov;
335 num_reqs++;
336 }
337
338 submit_requests(s, mrb, start, num_reqs, niov);
339 mrb->num_reqs = 0;
340 }
341
virtio_blk_handle_flush(VirtIOBlockReq * req,MultiReqBuffer * mrb)342 static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb)
343 {
344 VirtIOBlock *s = req->dev;
345
346 block_acct_start(blk_get_stats(s->blk), &req->acct, 0,
347 BLOCK_ACCT_FLUSH);
348
349 /*
350 * Make sure all outstanding writes are posted to the backing device.
351 */
352 if (mrb->is_write && mrb->num_reqs > 0) {
353 virtio_blk_submit_multireq(s, mrb);
354 }
355 blk_aio_flush(s->blk, virtio_blk_flush_complete, req);
356 }
357
virtio_blk_sect_range_ok(VirtIOBlock * dev,uint64_t sector,size_t size)358 static bool virtio_blk_sect_range_ok(VirtIOBlock *dev,
359 uint64_t sector, size_t size)
360 {
361 uint64_t nb_sectors = size >> BDRV_SECTOR_BITS;
362 uint64_t total_sectors;
363
364 if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
365 return false;
366 }
367 if (sector & dev->sector_mask) {
368 return false;
369 }
370 if (size % dev->conf.conf.logical_block_size) {
371 return false;
372 }
373 blk_get_geometry(dev->blk, &total_sectors);
374 if (sector > total_sectors || nb_sectors > total_sectors - sector) {
375 return false;
376 }
377 return true;
378 }
379
virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq * req,struct virtio_blk_discard_write_zeroes * dwz_hdr,bool is_write_zeroes)380 static uint8_t virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq *req,
381 struct virtio_blk_discard_write_zeroes *dwz_hdr, bool is_write_zeroes)
382 {
383 VirtIOBlock *s = req->dev;
384 VirtIODevice *vdev = VIRTIO_DEVICE(s);
385 uint64_t sector;
386 uint32_t num_sectors, flags, max_sectors;
387 uint8_t err_status;
388 int bytes;
389
390 sector = virtio_ldq_p(vdev, &dwz_hdr->sector);
391 num_sectors = virtio_ldl_p(vdev, &dwz_hdr->num_sectors);
392 flags = virtio_ldl_p(vdev, &dwz_hdr->flags);
393 max_sectors = is_write_zeroes ? s->conf.max_write_zeroes_sectors :
394 s->conf.max_discard_sectors;
395
396 /*
397 * max_sectors is at most BDRV_REQUEST_MAX_SECTORS, this check
398 * make us sure that "num_sectors << BDRV_SECTOR_BITS" can fit in
399 * the integer variable.
400 */
401 if (unlikely(num_sectors > max_sectors)) {
402 err_status = VIRTIO_BLK_S_IOERR;
403 goto err;
404 }
405
406 bytes = num_sectors << BDRV_SECTOR_BITS;
407
408 if (unlikely(!virtio_blk_sect_range_ok(s, sector, bytes))) {
409 err_status = VIRTIO_BLK_S_IOERR;
410 goto err;
411 }
412
413 /*
414 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard
415 * and write zeroes commands if any unknown flag is set.
416 */
417 if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
418 err_status = VIRTIO_BLK_S_UNSUPP;
419 goto err;
420 }
421
422 if (is_write_zeroes) { /* VIRTIO_BLK_T_WRITE_ZEROES */
423 int blk_aio_flags = 0;
424
425 if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) {
426 blk_aio_flags |= BDRV_REQ_MAY_UNMAP;
427 }
428
429 block_acct_start(blk_get_stats(s->blk), &req->acct, bytes,
430 BLOCK_ACCT_WRITE);
431
432 blk_aio_pwrite_zeroes(s->blk, sector << BDRV_SECTOR_BITS,
433 bytes, blk_aio_flags,
434 virtio_blk_discard_write_zeroes_complete, req);
435 } else { /* VIRTIO_BLK_T_DISCARD */
436 /*
437 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for
438 * discard commands if the unmap flag is set.
439 */
440 if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
441 err_status = VIRTIO_BLK_S_UNSUPP;
442 goto err;
443 }
444
445 blk_aio_pdiscard(s->blk, sector << BDRV_SECTOR_BITS, bytes,
446 virtio_blk_discard_write_zeroes_complete, req);
447 }
448
449 return VIRTIO_BLK_S_OK;
450
451 err:
452 if (is_write_zeroes) {
453 block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_WRITE);
454 }
455 return err_status;
456 }
457
458 typedef struct ZoneCmdData {
459 VirtIOBlockReq *req;
460 struct iovec *in_iov;
461 unsigned in_num;
462 union {
463 struct {
464 unsigned int nr_zones;
465 BlockZoneDescriptor *zones;
466 } zone_report_data;
467 struct {
468 int64_t offset;
469 } zone_append_data;
470 };
471 } ZoneCmdData;
472
473 /*
474 * check zoned_request: error checking before issuing requests. If all checks
475 * passed, return true.
476 * append: true if only zone append requests issued.
477 */
check_zoned_request(VirtIOBlock * s,int64_t offset,int64_t len,bool append,uint8_t * status)478 static bool check_zoned_request(VirtIOBlock *s, int64_t offset, int64_t len,
479 bool append, uint8_t *status) {
480 BlockDriverState *bs = blk_bs(s->blk);
481 int index;
482
483 if (!virtio_has_feature(s->host_features, VIRTIO_BLK_F_ZONED)) {
484 *status = VIRTIO_BLK_S_UNSUPP;
485 return false;
486 }
487
488 if (offset < 0 || len < 0 || len > (bs->total_sectors << BDRV_SECTOR_BITS)
489 || offset > (bs->total_sectors << BDRV_SECTOR_BITS) - len) {
490 *status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
491 return false;
492 }
493
494 if (append) {
495 if (bs->bl.write_granularity) {
496 if ((offset % bs->bl.write_granularity) != 0) {
497 *status = VIRTIO_BLK_S_ZONE_UNALIGNED_WP;
498 return false;
499 }
500 }
501
502 index = offset / bs->bl.zone_size;
503 if (BDRV_ZT_IS_CONV(bs->wps->wp[index])) {
504 *status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
505 return false;
506 }
507
508 if (len / 512 > bs->bl.max_append_sectors) {
509 if (bs->bl.max_append_sectors == 0) {
510 *status = VIRTIO_BLK_S_UNSUPP;
511 } else {
512 *status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
513 }
514 return false;
515 }
516 }
517 return true;
518 }
519
virtio_blk_zone_report_complete(void * opaque,int ret)520 static void virtio_blk_zone_report_complete(void *opaque, int ret)
521 {
522 ZoneCmdData *data = opaque;
523 VirtIOBlockReq *req = data->req;
524 VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
525 struct iovec *in_iov = data->in_iov;
526 unsigned in_num = data->in_num;
527 int64_t zrp_size, n, j = 0;
528 int64_t nz = data->zone_report_data.nr_zones;
529 int8_t err_status = VIRTIO_BLK_S_OK;
530 struct virtio_blk_zone_report zrp_hdr = (struct virtio_blk_zone_report) {
531 .nr_zones = cpu_to_le64(nz),
532 };
533
534 trace_virtio_blk_zone_report_complete(vdev, req, nz, ret);
535 if (ret) {
536 err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
537 goto out;
538 }
539
540 zrp_size = sizeof(struct virtio_blk_zone_report)
541 + sizeof(struct virtio_blk_zone_descriptor) * nz;
542 n = iov_from_buf(in_iov, in_num, 0, &zrp_hdr, sizeof(zrp_hdr));
543 if (n != sizeof(zrp_hdr)) {
544 virtio_error(vdev, "Driver provided input buffer that is too small!");
545 err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
546 goto out;
547 }
548
549 for (size_t i = sizeof(zrp_hdr); i < zrp_size;
550 i += sizeof(struct virtio_blk_zone_descriptor), ++j) {
551 struct virtio_blk_zone_descriptor desc =
552 (struct virtio_blk_zone_descriptor) {
553 .z_start = cpu_to_le64(data->zone_report_data.zones[j].start
554 >> BDRV_SECTOR_BITS),
555 .z_cap = cpu_to_le64(data->zone_report_data.zones[j].cap
556 >> BDRV_SECTOR_BITS),
557 .z_wp = cpu_to_le64(data->zone_report_data.zones[j].wp
558 >> BDRV_SECTOR_BITS),
559 };
560
561 switch (data->zone_report_data.zones[j].type) {
562 case BLK_ZT_CONV:
563 desc.z_type = VIRTIO_BLK_ZT_CONV;
564 break;
565 case BLK_ZT_SWR:
566 desc.z_type = VIRTIO_BLK_ZT_SWR;
567 break;
568 case BLK_ZT_SWP:
569 desc.z_type = VIRTIO_BLK_ZT_SWP;
570 break;
571 default:
572 g_assert_not_reached();
573 }
574
575 switch (data->zone_report_data.zones[j].state) {
576 case BLK_ZS_RDONLY:
577 desc.z_state = VIRTIO_BLK_ZS_RDONLY;
578 break;
579 case BLK_ZS_OFFLINE:
580 desc.z_state = VIRTIO_BLK_ZS_OFFLINE;
581 break;
582 case BLK_ZS_EMPTY:
583 desc.z_state = VIRTIO_BLK_ZS_EMPTY;
584 break;
585 case BLK_ZS_CLOSED:
586 desc.z_state = VIRTIO_BLK_ZS_CLOSED;
587 break;
588 case BLK_ZS_FULL:
589 desc.z_state = VIRTIO_BLK_ZS_FULL;
590 break;
591 case BLK_ZS_EOPEN:
592 desc.z_state = VIRTIO_BLK_ZS_EOPEN;
593 break;
594 case BLK_ZS_IOPEN:
595 desc.z_state = VIRTIO_BLK_ZS_IOPEN;
596 break;
597 case BLK_ZS_NOT_WP:
598 desc.z_state = VIRTIO_BLK_ZS_NOT_WP;
599 break;
600 default:
601 g_assert_not_reached();
602 }
603
604 /* TODO: it takes O(n^2) time complexity. Optimizations required. */
605 n = iov_from_buf(in_iov, in_num, i, &desc, sizeof(desc));
606 if (n != sizeof(desc)) {
607 virtio_error(vdev, "Driver provided input buffer "
608 "for descriptors that is too small!");
609 err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
610 }
611 }
612
613 out:
614 virtio_blk_req_complete(req, err_status);
615 virtio_blk_free_request(req);
616 g_free(data->zone_report_data.zones);
617 g_free(data);
618 }
619
virtio_blk_handle_zone_report(VirtIOBlockReq * req,struct iovec * in_iov,unsigned in_num)620 static void virtio_blk_handle_zone_report(VirtIOBlockReq *req,
621 struct iovec *in_iov,
622 unsigned in_num)
623 {
624 VirtIOBlock *s = req->dev;
625 VirtIODevice *vdev = VIRTIO_DEVICE(s);
626 unsigned int nr_zones;
627 ZoneCmdData *data;
628 int64_t zone_size, offset;
629 uint8_t err_status;
630
631 if (req->in_len < sizeof(struct virtio_blk_inhdr) +
632 sizeof(struct virtio_blk_zone_report) +
633 sizeof(struct virtio_blk_zone_descriptor)) {
634 virtio_error(vdev, "in buffer too small for zone report");
635 err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
636 goto out;
637 }
638
639 /* start byte offset of the zone report */
640 offset = virtio_ldq_p(vdev, &req->out.sector) << BDRV_SECTOR_BITS;
641 if (!check_zoned_request(s, offset, 0, false, &err_status)) {
642 goto out;
643 }
644 nr_zones = (req->in_len - sizeof(struct virtio_blk_inhdr) -
645 sizeof(struct virtio_blk_zone_report)) /
646 sizeof(struct virtio_blk_zone_descriptor);
647 trace_virtio_blk_handle_zone_report(vdev, req,
648 offset >> BDRV_SECTOR_BITS, nr_zones);
649
650 zone_size = sizeof(BlockZoneDescriptor) * nr_zones;
651 data = g_malloc(sizeof(ZoneCmdData));
652 data->req = req;
653 data->in_iov = in_iov;
654 data->in_num = in_num;
655 data->zone_report_data.nr_zones = nr_zones;
656 data->zone_report_data.zones = g_malloc(zone_size),
657
658 blk_aio_zone_report(s->blk, offset, &data->zone_report_data.nr_zones,
659 data->zone_report_data.zones,
660 virtio_blk_zone_report_complete, data);
661 return;
662 out:
663 virtio_blk_req_complete(req, err_status);
664 virtio_blk_free_request(req);
665 }
666
virtio_blk_zone_mgmt_complete(void * opaque,int ret)667 static void virtio_blk_zone_mgmt_complete(void *opaque, int ret)
668 {
669 VirtIOBlockReq *req = opaque;
670 VirtIOBlock *s = req->dev;
671 VirtIODevice *vdev = VIRTIO_DEVICE(s);
672 int8_t err_status = VIRTIO_BLK_S_OK;
673 trace_virtio_blk_zone_mgmt_complete(vdev, req,ret);
674
675 if (ret) {
676 err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
677 }
678
679 virtio_blk_req_complete(req, err_status);
680 virtio_blk_free_request(req);
681 }
682
virtio_blk_handle_zone_mgmt(VirtIOBlockReq * req,BlockZoneOp op)683 static int virtio_blk_handle_zone_mgmt(VirtIOBlockReq *req, BlockZoneOp op)
684 {
685 VirtIOBlock *s = req->dev;
686 VirtIODevice *vdev = VIRTIO_DEVICE(s);
687 BlockDriverState *bs = blk_bs(s->blk);
688 int64_t offset = virtio_ldq_p(vdev, &req->out.sector) << BDRV_SECTOR_BITS;
689 uint64_t len;
690 uint64_t capacity = bs->total_sectors << BDRV_SECTOR_BITS;
691 uint8_t err_status = VIRTIO_BLK_S_OK;
692
693 uint32_t type = virtio_ldl_p(vdev, &req->out.type);
694 if (type == VIRTIO_BLK_T_ZONE_RESET_ALL) {
695 /* Entire drive capacity */
696 offset = 0;
697 len = capacity;
698 trace_virtio_blk_handle_zone_reset_all(vdev, req, 0,
699 bs->total_sectors);
700 } else {
701 if (bs->bl.zone_size > capacity - offset) {
702 /* The zoned device allows the last smaller zone. */
703 len = capacity - bs->bl.zone_size * (bs->bl.nr_zones - 1);
704 } else {
705 len = bs->bl.zone_size;
706 }
707 trace_virtio_blk_handle_zone_mgmt(vdev, req, op,
708 offset >> BDRV_SECTOR_BITS,
709 len >> BDRV_SECTOR_BITS);
710 }
711
712 if (!check_zoned_request(s, offset, len, false, &err_status)) {
713 goto out;
714 }
715
716 blk_aio_zone_mgmt(s->blk, op, offset, len,
717 virtio_blk_zone_mgmt_complete, req);
718
719 return 0;
720 out:
721 virtio_blk_req_complete(req, err_status);
722 virtio_blk_free_request(req);
723 return err_status;
724 }
725
virtio_blk_zone_append_complete(void * opaque,int ret)726 static void virtio_blk_zone_append_complete(void *opaque, int ret)
727 {
728 ZoneCmdData *data = opaque;
729 VirtIOBlockReq *req = data->req;
730 VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
731 int64_t append_sector, n;
732 uint8_t err_status = VIRTIO_BLK_S_OK;
733
734 if (ret) {
735 err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
736 goto out;
737 }
738
739 virtio_stq_p(vdev, &append_sector,
740 data->zone_append_data.offset >> BDRV_SECTOR_BITS);
741 n = iov_from_buf(data->in_iov, data->in_num, 0, &append_sector,
742 sizeof(append_sector));
743 if (n != sizeof(append_sector)) {
744 virtio_error(vdev, "Driver provided input buffer less than size of "
745 "append_sector");
746 err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
747 goto out;
748 }
749 trace_virtio_blk_zone_append_complete(vdev, req, append_sector, ret);
750
751 out:
752 virtio_blk_req_complete(req, err_status);
753 virtio_blk_free_request(req);
754 g_free(data);
755 }
756
virtio_blk_handle_zone_append(VirtIOBlockReq * req,struct iovec * out_iov,struct iovec * in_iov,uint64_t out_num,unsigned in_num)757 static int virtio_blk_handle_zone_append(VirtIOBlockReq *req,
758 struct iovec *out_iov,
759 struct iovec *in_iov,
760 uint64_t out_num,
761 unsigned in_num) {
762 VirtIOBlock *s = req->dev;
763 VirtIODevice *vdev = VIRTIO_DEVICE(s);
764 uint8_t err_status = VIRTIO_BLK_S_OK;
765
766 int64_t offset = virtio_ldq_p(vdev, &req->out.sector) << BDRV_SECTOR_BITS;
767 int64_t len = iov_size(out_iov, out_num);
768 ZoneCmdData *data;
769
770 trace_virtio_blk_handle_zone_append(vdev, req, offset >> BDRV_SECTOR_BITS);
771 if (!check_zoned_request(s, offset, len, true, &err_status)) {
772 goto out;
773 }
774
775 data = g_malloc(sizeof(ZoneCmdData));
776 data->req = req;
777 data->in_iov = in_iov;
778 data->in_num = in_num;
779 data->zone_append_data.offset = offset;
780 qemu_iovec_init_external(&req->qiov, out_iov, out_num);
781
782 block_acct_start(blk_get_stats(s->blk), &req->acct, len,
783 BLOCK_ACCT_ZONE_APPEND);
784
785 blk_aio_zone_append(s->blk, &data->zone_append_data.offset, &req->qiov, 0,
786 virtio_blk_zone_append_complete, data);
787 return 0;
788
789 out:
790 virtio_blk_req_complete(req, err_status);
791 virtio_blk_free_request(req);
792 return err_status;
793 }
794
virtio_blk_handle_request(VirtIOBlockReq * req,MultiReqBuffer * mrb)795 static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
796 {
797 uint32_t type;
798 struct iovec *in_iov = req->elem.in_sg;
799 struct iovec *out_iov = req->elem.out_sg;
800 unsigned in_num = req->elem.in_num;
801 unsigned out_num = req->elem.out_num;
802 VirtIOBlock *s = req->dev;
803 VirtIODevice *vdev = VIRTIO_DEVICE(s);
804
805 if (req->elem.out_num < 1 || req->elem.in_num < 1) {
806 virtio_error(vdev, "virtio-blk missing headers");
807 return -1;
808 }
809
810 if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
811 sizeof(req->out)) != sizeof(req->out))) {
812 virtio_error(vdev, "virtio-blk request outhdr too short");
813 return -1;
814 }
815
816 iov_discard_front_undoable(&out_iov, &out_num, sizeof(req->out),
817 &req->outhdr_undo);
818
819 if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
820 virtio_error(vdev, "virtio-blk request inhdr too short");
821 iov_discard_undo(&req->outhdr_undo);
822 return -1;
823 }
824
825 /* We always touch the last byte, so just see how big in_iov is. */
826 req->in_len = iov_size(in_iov, in_num);
827 req->in = (void *)in_iov[in_num - 1].iov_base
828 + in_iov[in_num - 1].iov_len
829 - sizeof(struct virtio_blk_inhdr);
830 iov_discard_back_undoable(in_iov, &in_num, sizeof(struct virtio_blk_inhdr),
831 &req->inhdr_undo);
832
833 type = virtio_ldl_p(vdev, &req->out.type);
834
835 /* VIRTIO_BLK_T_OUT defines the command direction. VIRTIO_BLK_T_BARRIER
836 * is an optional flag. Although a guest should not send this flag if
837 * not negotiated we ignored it in the past. So keep ignoring it. */
838 switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) {
839 case VIRTIO_BLK_T_IN:
840 {
841 bool is_write = type & VIRTIO_BLK_T_OUT;
842 req->sector_num = virtio_ldq_p(vdev, &req->out.sector);
843
844 if (is_write) {
845 qemu_iovec_init_external(&req->qiov, out_iov, out_num);
846 trace_virtio_blk_handle_write(vdev, req, req->sector_num,
847 req->qiov.size / BDRV_SECTOR_SIZE);
848 } else {
849 qemu_iovec_init_external(&req->qiov, in_iov, in_num);
850 trace_virtio_blk_handle_read(vdev, req, req->sector_num,
851 req->qiov.size / BDRV_SECTOR_SIZE);
852 }
853
854 if (!virtio_blk_sect_range_ok(s, req->sector_num, req->qiov.size)) {
855 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
856 block_acct_invalid(blk_get_stats(s->blk),
857 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
858 virtio_blk_free_request(req);
859 return 0;
860 }
861
862 block_acct_start(blk_get_stats(s->blk), &req->acct, req->qiov.size,
863 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
864
865 /* merge would exceed maximum number of requests or IO direction
866 * changes */
867 if (mrb->num_reqs > 0 && (mrb->num_reqs == VIRTIO_BLK_MAX_MERGE_REQS ||
868 is_write != mrb->is_write ||
869 !s->conf.request_merging)) {
870 virtio_blk_submit_multireq(s, mrb);
871 }
872
873 assert(mrb->num_reqs < VIRTIO_BLK_MAX_MERGE_REQS);
874 mrb->reqs[mrb->num_reqs++] = req;
875 mrb->is_write = is_write;
876 break;
877 }
878 case VIRTIO_BLK_T_FLUSH:
879 virtio_blk_handle_flush(req, mrb);
880 break;
881 case VIRTIO_BLK_T_ZONE_REPORT:
882 virtio_blk_handle_zone_report(req, in_iov, in_num);
883 break;
884 case VIRTIO_BLK_T_ZONE_OPEN:
885 virtio_blk_handle_zone_mgmt(req, BLK_ZO_OPEN);
886 break;
887 case VIRTIO_BLK_T_ZONE_CLOSE:
888 virtio_blk_handle_zone_mgmt(req, BLK_ZO_CLOSE);
889 break;
890 case VIRTIO_BLK_T_ZONE_FINISH:
891 virtio_blk_handle_zone_mgmt(req, BLK_ZO_FINISH);
892 break;
893 case VIRTIO_BLK_T_ZONE_RESET:
894 virtio_blk_handle_zone_mgmt(req, BLK_ZO_RESET);
895 break;
896 case VIRTIO_BLK_T_ZONE_RESET_ALL:
897 virtio_blk_handle_zone_mgmt(req, BLK_ZO_RESET);
898 break;
899 case VIRTIO_BLK_T_SCSI_CMD:
900 virtio_blk_handle_scsi(req);
901 break;
902 case VIRTIO_BLK_T_GET_ID:
903 {
904 /*
905 * NB: per existing s/n string convention the string is
906 * terminated by '\0' only when shorter than buffer.
907 */
908 const char *serial = s->conf.serial ? s->conf.serial : "";
909 size_t size = MIN(strlen(serial) + 1,
910 MIN(iov_size(in_iov, in_num),
911 VIRTIO_BLK_ID_BYTES));
912 iov_from_buf(in_iov, in_num, 0, serial, size);
913 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
914 virtio_blk_free_request(req);
915 break;
916 }
917 case VIRTIO_BLK_T_ZONE_APPEND & ~VIRTIO_BLK_T_OUT:
918 /*
919 * Passing out_iov/out_num and in_iov/in_num is not safe
920 * to access req->elem.out_sg directly because it may be
921 * modified by virtio_blk_handle_request().
922 */
923 virtio_blk_handle_zone_append(req, out_iov, in_iov, out_num, in_num);
924 break;
925 /*
926 * VIRTIO_BLK_T_DISCARD and VIRTIO_BLK_T_WRITE_ZEROES are defined with
927 * VIRTIO_BLK_T_OUT flag set. We masked this flag in the switch statement,
928 * so we must mask it for these requests, then we will check if it is set.
929 */
930 case VIRTIO_BLK_T_DISCARD & ~VIRTIO_BLK_T_OUT:
931 case VIRTIO_BLK_T_WRITE_ZEROES & ~VIRTIO_BLK_T_OUT:
932 {
933 struct virtio_blk_discard_write_zeroes dwz_hdr;
934 size_t out_len = iov_size(out_iov, out_num);
935 bool is_write_zeroes = (type & ~VIRTIO_BLK_T_BARRIER) ==
936 VIRTIO_BLK_T_WRITE_ZEROES;
937 uint8_t err_status;
938
939 /*
940 * Unsupported if VIRTIO_BLK_T_OUT is not set or the request contains
941 * more than one segment.
942 */
943 if (unlikely(!(type & VIRTIO_BLK_T_OUT) ||
944 out_len > sizeof(dwz_hdr))) {
945 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
946 virtio_blk_free_request(req);
947 return 0;
948 }
949
950 if (unlikely(iov_to_buf(out_iov, out_num, 0, &dwz_hdr,
951 sizeof(dwz_hdr)) != sizeof(dwz_hdr))) {
952 iov_discard_undo(&req->inhdr_undo);
953 iov_discard_undo(&req->outhdr_undo);
954 virtio_error(vdev, "virtio-blk discard/write_zeroes header"
955 " too short");
956 return -1;
957 }
958
959 err_status = virtio_blk_handle_discard_write_zeroes(req, &dwz_hdr,
960 is_write_zeroes);
961 if (err_status != VIRTIO_BLK_S_OK) {
962 virtio_blk_req_complete(req, err_status);
963 virtio_blk_free_request(req);
964 }
965
966 break;
967 }
968 default:
969 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
970 virtio_blk_free_request(req);
971 }
972 return 0;
973 }
974
virtio_blk_handle_vq(VirtIOBlock * s,VirtQueue * vq)975 void virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq)
976 {
977 VirtIOBlockReq *req;
978 MultiReqBuffer mrb = {};
979 bool suppress_notifications = virtio_queue_get_notification(vq);
980
981 defer_call_begin();
982
983 do {
984 if (suppress_notifications) {
985 virtio_queue_set_notification(vq, 0);
986 }
987
988 while ((req = virtio_blk_get_request(s, vq))) {
989 if (virtio_blk_handle_request(req, &mrb)) {
990 virtqueue_detach_element(req->vq, &req->elem, 0);
991 virtio_blk_free_request(req);
992 break;
993 }
994 }
995
996 if (suppress_notifications) {
997 virtio_queue_set_notification(vq, 1);
998 }
999 } while (!virtio_queue_empty(vq));
1000
1001 if (mrb.num_reqs) {
1002 virtio_blk_submit_multireq(s, &mrb);
1003 }
1004
1005 defer_call_end();
1006 }
1007
virtio_blk_handle_output(VirtIODevice * vdev,VirtQueue * vq)1008 static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
1009 {
1010 VirtIOBlock *s = (VirtIOBlock *)vdev;
1011
1012 if (!s->ioeventfd_disabled && !s->ioeventfd_started) {
1013 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
1014 * ioeventfd here instead of waiting for .set_status().
1015 */
1016 virtio_device_start_ioeventfd(vdev);
1017 if (!s->ioeventfd_disabled) {
1018 return;
1019 }
1020 }
1021
1022 virtio_blk_handle_vq(s, vq);
1023 }
1024
virtio_blk_dma_restart_bh(void * opaque)1025 static void virtio_blk_dma_restart_bh(void *opaque)
1026 {
1027 VirtIOBlockReq *req = opaque;
1028 VirtIOBlock *s = req->dev; /* we're called with at least one request */
1029
1030 MultiReqBuffer mrb = {};
1031
1032 while (req) {
1033 VirtIOBlockReq *next = req->next;
1034 if (virtio_blk_handle_request(req, &mrb)) {
1035 /* Device is now broken and won't do any processing until it gets
1036 * reset. Already queued requests will be lost: let's purge them.
1037 */
1038 while (req) {
1039 next = req->next;
1040 virtqueue_detach_element(req->vq, &req->elem, 0);
1041 virtio_blk_free_request(req);
1042 req = next;
1043 }
1044 break;
1045 }
1046 req = next;
1047 }
1048
1049 if (mrb.num_reqs) {
1050 virtio_blk_submit_multireq(s, &mrb);
1051 }
1052
1053 /* Paired with inc in virtio_blk_dma_restart_cb() */
1054 blk_dec_in_flight(s->conf.conf.blk);
1055 }
1056
virtio_blk_dma_restart_cb(void * opaque,bool running,RunState state)1057 static void virtio_blk_dma_restart_cb(void *opaque, bool running,
1058 RunState state)
1059 {
1060 VirtIOBlock *s = opaque;
1061 uint16_t num_queues = s->conf.num_queues;
1062 g_autofree VirtIOBlockReq **vq_rq = NULL;
1063 VirtIOBlockReq *rq;
1064
1065 if (!running) {
1066 return;
1067 }
1068
1069 /* Split the device-wide s->rq request list into per-vq request lists */
1070 vq_rq = g_new0(VirtIOBlockReq *, num_queues);
1071
1072 WITH_QEMU_LOCK_GUARD(&s->rq_lock) {
1073 rq = s->rq;
1074 s->rq = NULL;
1075 }
1076
1077 while (rq) {
1078 VirtIOBlockReq *next = rq->next;
1079 uint16_t idx = virtio_get_queue_index(rq->vq);
1080
1081 /* Only num_queues vqs were created so vq_rq[idx] is within bounds */
1082 assert(idx < num_queues);
1083 rq->next = vq_rq[idx];
1084 vq_rq[idx] = rq;
1085 rq = next;
1086 }
1087
1088 /* Schedule a BH to submit the requests in each vq's AioContext */
1089 for (uint16_t i = 0; i < num_queues; i++) {
1090 if (!vq_rq[i]) {
1091 continue;
1092 }
1093
1094 /* Paired with dec in virtio_blk_dma_restart_bh() */
1095 blk_inc_in_flight(s->conf.conf.blk);
1096
1097 aio_bh_schedule_oneshot(s->vq_aio_context[i],
1098 virtio_blk_dma_restart_bh,
1099 vq_rq[i]);
1100 }
1101 }
1102
virtio_blk_reset(VirtIODevice * vdev)1103 static void virtio_blk_reset(VirtIODevice *vdev)
1104 {
1105 VirtIOBlock *s = VIRTIO_BLK(vdev);
1106 VirtIOBlockReq *req;
1107
1108 /* Dataplane has stopped... */
1109 assert(!s->ioeventfd_started);
1110
1111 /* ...but requests may still be in flight. */
1112 blk_drain(s->blk);
1113
1114 /* We drop queued requests after blk_drain() because blk_drain() itself can
1115 * produce them. */
1116 WITH_QEMU_LOCK_GUARD(&s->rq_lock) {
1117 while (s->rq) {
1118 req = s->rq;
1119 s->rq = req->next;
1120
1121 /* No other threads can access req->vq here */
1122 virtqueue_detach_element(req->vq, &req->elem, 0);
1123
1124 virtio_blk_free_request(req);
1125 }
1126 }
1127
1128 blk_set_enable_write_cache(s->blk, s->original_wce);
1129 }
1130
1131 /* coalesce internal state, copy to pci i/o region 0
1132 */
virtio_blk_update_config(VirtIODevice * vdev,uint8_t * config)1133 static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
1134 {
1135 VirtIOBlock *s = VIRTIO_BLK(vdev);
1136 BlockConf *conf = &s->conf.conf;
1137 BlockDriverState *bs = blk_bs(s->blk);
1138 struct virtio_blk_config blkcfg;
1139 uint64_t capacity;
1140 int64_t length;
1141 int blk_size = conf->logical_block_size;
1142
1143 blk_get_geometry(s->blk, &capacity);
1144 memset(&blkcfg, 0, sizeof(blkcfg));
1145 virtio_stq_p(vdev, &blkcfg.capacity, capacity);
1146 virtio_stl_p(vdev, &blkcfg.seg_max,
1147 s->conf.seg_max_adjust ? s->conf.queue_size - 2 : 128 - 2);
1148 virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls);
1149 virtio_stl_p(vdev, &blkcfg.blk_size, blk_size);
1150 virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size);
1151 virtio_stl_p(vdev, &blkcfg.opt_io_size, conf->opt_io_size / blk_size);
1152 blkcfg.geometry.heads = conf->heads;
1153 /*
1154 * We must ensure that the block device capacity is a multiple of
1155 * the logical block size. If that is not the case, let's use
1156 * sector_mask to adopt the geometry to have a correct picture.
1157 * For those devices where the capacity is ok for the given geometry
1158 * we don't touch the sector value of the geometry, since some devices
1159 * (like s390 dasd) need a specific value. Here the capacity is already
1160 * cyls*heads*secs*blk_size and the sector value is not block size
1161 * divided by 512 - instead it is the amount of blk_size blocks
1162 * per track (cylinder).
1163 */
1164 length = blk_getlength(s->blk);
1165 if (length > 0 && length / conf->heads / conf->secs % blk_size) {
1166 blkcfg.geometry.sectors = conf->secs & ~s->sector_mask;
1167 } else {
1168 blkcfg.geometry.sectors = conf->secs;
1169 }
1170 blkcfg.size_max = 0;
1171 blkcfg.physical_block_exp = get_physical_block_exp(conf);
1172 blkcfg.alignment_offset = 0;
1173 blkcfg.wce = blk_enable_write_cache(s->blk);
1174 virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues);
1175 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD)) {
1176 uint32_t discard_granularity = conf->discard_granularity;
1177 if (discard_granularity == -1 || !s->conf.report_discard_granularity) {
1178 discard_granularity = blk_size;
1179 }
1180 virtio_stl_p(vdev, &blkcfg.max_discard_sectors,
1181 s->conf.max_discard_sectors);
1182 virtio_stl_p(vdev, &blkcfg.discard_sector_alignment,
1183 discard_granularity >> BDRV_SECTOR_BITS);
1184 /*
1185 * We support only one segment per request since multiple segments
1186 * are not widely used and there are no userspace APIs that allow
1187 * applications to submit multiple segments in a single call.
1188 */
1189 virtio_stl_p(vdev, &blkcfg.max_discard_seg, 1);
1190 }
1191 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES)) {
1192 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_sectors,
1193 s->conf.max_write_zeroes_sectors);
1194 blkcfg.write_zeroes_may_unmap = 1;
1195 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_seg, 1);
1196 }
1197 if (bs->bl.zoned != BLK_Z_NONE) {
1198 switch (bs->bl.zoned) {
1199 case BLK_Z_HM:
1200 blkcfg.zoned.model = VIRTIO_BLK_Z_HM;
1201 break;
1202 case BLK_Z_HA:
1203 blkcfg.zoned.model = VIRTIO_BLK_Z_HA;
1204 break;
1205 default:
1206 g_assert_not_reached();
1207 }
1208
1209 virtio_stl_p(vdev, &blkcfg.zoned.zone_sectors,
1210 bs->bl.zone_size / 512);
1211 virtio_stl_p(vdev, &blkcfg.zoned.max_active_zones,
1212 bs->bl.max_active_zones);
1213 virtio_stl_p(vdev, &blkcfg.zoned.max_open_zones,
1214 bs->bl.max_open_zones);
1215 virtio_stl_p(vdev, &blkcfg.zoned.write_granularity, blk_size);
1216 virtio_stl_p(vdev, &blkcfg.zoned.max_append_sectors,
1217 bs->bl.max_append_sectors);
1218 } else {
1219 blkcfg.zoned.model = VIRTIO_BLK_Z_NONE;
1220 }
1221 memcpy(config, &blkcfg, s->config_size);
1222 }
1223
virtio_blk_set_config(VirtIODevice * vdev,const uint8_t * config)1224 static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
1225 {
1226 VirtIOBlock *s = VIRTIO_BLK(vdev);
1227 struct virtio_blk_config blkcfg;
1228
1229 memcpy(&blkcfg, config, s->config_size);
1230
1231 blk_set_enable_write_cache(s->blk, blkcfg.wce != 0);
1232 }
1233
virtio_blk_get_features(VirtIODevice * vdev,uint64_t features,Error ** errp)1234 static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features,
1235 Error **errp)
1236 {
1237 VirtIOBlock *s = VIRTIO_BLK(vdev);
1238
1239 /* Firstly sync all virtio-blk possible supported features */
1240 features |= s->host_features;
1241
1242 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
1243 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
1244 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
1245 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
1246 if (!virtio_has_feature(features, VIRTIO_F_VERSION_1)) {
1247 virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT);
1248 /* Added for historical reasons, removing it could break migration. */
1249 virtio_add_feature(&features, VIRTIO_BLK_F_SCSI);
1250 }
1251
1252 if (blk_enable_write_cache(s->blk) ||
1253 (s->conf.x_enable_wce_if_config_wce &&
1254 virtio_has_feature(features, VIRTIO_BLK_F_CONFIG_WCE))) {
1255 virtio_add_feature(&features, VIRTIO_BLK_F_WCE);
1256 }
1257 if (!blk_is_writable(s->blk)) {
1258 virtio_add_feature(&features, VIRTIO_BLK_F_RO);
1259 }
1260 if (s->conf.num_queues > 1) {
1261 virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
1262 }
1263
1264 return features;
1265 }
1266
virtio_blk_set_status(VirtIODevice * vdev,uint8_t status)1267 static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
1268 {
1269 VirtIOBlock *s = VIRTIO_BLK(vdev);
1270
1271 if (!(status & (VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK))) {
1272 assert(!s->ioeventfd_started);
1273 }
1274
1275 if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
1276 return;
1277 }
1278
1279 /* A guest that supports VIRTIO_BLK_F_CONFIG_WCE must be able to send
1280 * cache flushes. Thus, the "auto writethrough" behavior is never
1281 * necessary for guests that support the VIRTIO_BLK_F_CONFIG_WCE feature.
1282 * Leaving it enabled would break the following sequence:
1283 *
1284 * Guest started with "-drive cache=writethrough"
1285 * Guest sets status to 0
1286 * Guest sets DRIVER bit in status field
1287 * Guest reads host features (WCE=0, CONFIG_WCE=1)
1288 * Guest writes guest features (WCE=0, CONFIG_WCE=1)
1289 * Guest writes 1 to the WCE configuration field (writeback mode)
1290 * Guest sets DRIVER_OK bit in status field
1291 *
1292 * s->blk would erroneously be placed in writethrough mode.
1293 */
1294 if (!virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) {
1295 blk_set_enable_write_cache(s->blk,
1296 virtio_vdev_has_feature(vdev,
1297 VIRTIO_BLK_F_WCE));
1298 }
1299 }
1300
virtio_blk_save_device(VirtIODevice * vdev,QEMUFile * f)1301 static void virtio_blk_save_device(VirtIODevice *vdev, QEMUFile *f)
1302 {
1303 VirtIOBlock *s = VIRTIO_BLK(vdev);
1304
1305 WITH_QEMU_LOCK_GUARD(&s->rq_lock) {
1306 VirtIOBlockReq *req = s->rq;
1307
1308 while (req) {
1309 qemu_put_sbyte(f, 1);
1310
1311 if (s->conf.num_queues > 1) {
1312 qemu_put_be32(f, virtio_get_queue_index(req->vq));
1313 }
1314
1315 qemu_put_virtqueue_element(vdev, f, &req->elem);
1316 req = req->next;
1317 }
1318 }
1319
1320 qemu_put_sbyte(f, 0);
1321 }
1322
virtio_blk_load_device(VirtIODevice * vdev,QEMUFile * f,int version_id)1323 static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f,
1324 int version_id)
1325 {
1326 VirtIOBlock *s = VIRTIO_BLK(vdev);
1327
1328 while (qemu_get_sbyte(f)) {
1329 unsigned nvqs = s->conf.num_queues;
1330 unsigned vq_idx = 0;
1331 VirtIOBlockReq *req;
1332
1333 if (nvqs > 1) {
1334 vq_idx = qemu_get_be32(f);
1335
1336 if (vq_idx >= nvqs) {
1337 error_report("Invalid virtqueue index in request list: %#x",
1338 vq_idx);
1339 return -EINVAL;
1340 }
1341 }
1342
1343 req = qemu_get_virtqueue_element(vdev, f, sizeof(VirtIOBlockReq));
1344 virtio_blk_init_request(s, virtio_get_queue(vdev, vq_idx), req);
1345
1346 WITH_QEMU_LOCK_GUARD(&s->rq_lock) {
1347 req->next = s->rq;
1348 s->rq = req;
1349 }
1350 }
1351
1352 return 0;
1353 }
1354
virtio_resize_cb(void * opaque)1355 static void virtio_resize_cb(void *opaque)
1356 {
1357 VirtIODevice *vdev = opaque;
1358
1359 assert(qemu_get_current_aio_context() == qemu_get_aio_context());
1360 virtio_notify_config(vdev);
1361 }
1362
virtio_blk_resize(void * opaque)1363 static void virtio_blk_resize(void *opaque)
1364 {
1365 VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
1366
1367 /*
1368 * virtio_notify_config() needs to acquire the BQL,
1369 * so it can't be called from an iothread. Instead, schedule
1370 * it to be run in the main context BH.
1371 */
1372 aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev);
1373 }
1374
virtio_blk_ioeventfd_detach(VirtIOBlock * s)1375 static void virtio_blk_ioeventfd_detach(VirtIOBlock *s)
1376 {
1377 VirtIODevice *vdev = VIRTIO_DEVICE(s);
1378
1379 for (uint16_t i = 0; i < s->conf.num_queues; i++) {
1380 VirtQueue *vq = virtio_get_queue(vdev, i);
1381 virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]);
1382 }
1383 }
1384
virtio_blk_ioeventfd_attach(VirtIOBlock * s)1385 static void virtio_blk_ioeventfd_attach(VirtIOBlock *s)
1386 {
1387 VirtIODevice *vdev = VIRTIO_DEVICE(s);
1388
1389 for (uint16_t i = 0; i < s->conf.num_queues; i++) {
1390 VirtQueue *vq = virtio_get_queue(vdev, i);
1391 virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]);
1392 }
1393 }
1394
1395 /* Suspend virtqueue ioeventfd processing during drain */
virtio_blk_drained_begin(void * opaque)1396 static void virtio_blk_drained_begin(void *opaque)
1397 {
1398 VirtIOBlock *s = opaque;
1399
1400 if (s->ioeventfd_started) {
1401 virtio_blk_ioeventfd_detach(s);
1402 }
1403 }
1404
1405 /* Resume virtqueue ioeventfd processing after drain */
virtio_blk_drained_end(void * opaque)1406 static void virtio_blk_drained_end(void *opaque)
1407 {
1408 VirtIOBlock *s = opaque;
1409
1410 if (s->ioeventfd_started) {
1411 virtio_blk_ioeventfd_attach(s);
1412 }
1413 }
1414
1415 static const BlockDevOps virtio_block_ops = {
1416 .resize_cb = virtio_blk_resize,
1417 .drained_begin = virtio_blk_drained_begin,
1418 .drained_end = virtio_blk_drained_end,
1419 };
1420
1421 static bool
validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList * list,uint16_t num_queues,Error ** errp)1422 validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList *list,
1423 uint16_t num_queues, Error **errp)
1424 {
1425 g_autofree unsigned long *vqs = bitmap_new(num_queues);
1426 g_autoptr(GHashTable) iothreads =
1427 g_hash_table_new(g_str_hash, g_str_equal);
1428
1429 for (IOThreadVirtQueueMappingList *node = list; node; node = node->next) {
1430 const char *name = node->value->iothread;
1431 uint16List *vq;
1432
1433 if (!iothread_by_id(name)) {
1434 error_setg(errp, "IOThread \"%s\" object does not exist", name);
1435 return false;
1436 }
1437
1438 if (!g_hash_table_add(iothreads, (gpointer)name)) {
1439 error_setg(errp,
1440 "duplicate IOThread name \"%s\" in iothread-vq-mapping",
1441 name);
1442 return false;
1443 }
1444
1445 if (node != list) {
1446 if (!!node->value->vqs != !!list->value->vqs) {
1447 error_setg(errp, "either all items in iothread-vq-mapping "
1448 "must have vqs or none of them must have it");
1449 return false;
1450 }
1451 }
1452
1453 for (vq = node->value->vqs; vq; vq = vq->next) {
1454 if (vq->value >= num_queues) {
1455 error_setg(errp, "vq index %u for IOThread \"%s\" must be "
1456 "less than num_queues %u in iothread-vq-mapping",
1457 vq->value, name, num_queues);
1458 return false;
1459 }
1460
1461 if (test_and_set_bit(vq->value, vqs)) {
1462 error_setg(errp, "cannot assign vq %u to IOThread \"%s\" "
1463 "because it is already assigned", vq->value, name);
1464 return false;
1465 }
1466 }
1467 }
1468
1469 if (list->value->vqs) {
1470 for (uint16_t i = 0; i < num_queues; i++) {
1471 if (!test_bit(i, vqs)) {
1472 error_setg(errp,
1473 "missing vq %u IOThread assignment in iothread-vq-mapping",
1474 i);
1475 return false;
1476 }
1477 }
1478 }
1479
1480 return true;
1481 }
1482
1483 /**
1484 * apply_iothread_vq_mapping:
1485 * @iothread_vq_mapping_list: The mapping of virtqueues to IOThreads.
1486 * @vq_aio_context: The array of AioContext pointers to fill in.
1487 * @num_queues: The length of @vq_aio_context.
1488 * @errp: If an error occurs, a pointer to the area to store the error.
1489 *
1490 * Fill in the AioContext for each virtqueue in the @vq_aio_context array given
1491 * the iothread-vq-mapping parameter in @iothread_vq_mapping_list.
1492 *
1493 * Returns: %true on success, %false on failure.
1494 **/
apply_iothread_vq_mapping(IOThreadVirtQueueMappingList * iothread_vq_mapping_list,AioContext ** vq_aio_context,uint16_t num_queues,Error ** errp)1495 static bool apply_iothread_vq_mapping(
1496 IOThreadVirtQueueMappingList *iothread_vq_mapping_list,
1497 AioContext **vq_aio_context,
1498 uint16_t num_queues,
1499 Error **errp)
1500 {
1501 IOThreadVirtQueueMappingList *node;
1502 size_t num_iothreads = 0;
1503 size_t cur_iothread = 0;
1504
1505 if (!validate_iothread_vq_mapping_list(iothread_vq_mapping_list,
1506 num_queues, errp)) {
1507 return false;
1508 }
1509
1510 for (node = iothread_vq_mapping_list; node; node = node->next) {
1511 num_iothreads++;
1512 }
1513
1514 for (node = iothread_vq_mapping_list; node; node = node->next) {
1515 IOThread *iothread = iothread_by_id(node->value->iothread);
1516 AioContext *ctx = iothread_get_aio_context(iothread);
1517
1518 /* Released in virtio_blk_vq_aio_context_cleanup() */
1519 object_ref(OBJECT(iothread));
1520
1521 if (node->value->vqs) {
1522 uint16List *vq;
1523
1524 /* Explicit vq:IOThread assignment */
1525 for (vq = node->value->vqs; vq; vq = vq->next) {
1526 assert(vq->value < num_queues);
1527 vq_aio_context[vq->value] = ctx;
1528 }
1529 } else {
1530 /* Round-robin vq:IOThread assignment */
1531 for (unsigned i = cur_iothread; i < num_queues;
1532 i += num_iothreads) {
1533 vq_aio_context[i] = ctx;
1534 }
1535 }
1536
1537 cur_iothread++;
1538 }
1539
1540 return true;
1541 }
1542
1543 /* Context: BQL held */
virtio_blk_vq_aio_context_init(VirtIOBlock * s,Error ** errp)1544 static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp)
1545 {
1546 ERRP_GUARD();
1547 VirtIODevice *vdev = VIRTIO_DEVICE(s);
1548 VirtIOBlkConf *conf = &s->conf;
1549 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
1550 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
1551
1552 if (conf->iothread && conf->iothread_vq_mapping_list) {
1553 error_setg(errp,
1554 "iothread and iothread-vq-mapping properties cannot be set "
1555 "at the same time");
1556 return false;
1557 }
1558
1559 if (conf->iothread || conf->iothread_vq_mapping_list) {
1560 if (!k->set_guest_notifiers || !k->ioeventfd_assign) {
1561 error_setg(errp,
1562 "device is incompatible with iothread "
1563 "(transport does not support notifiers)");
1564 return false;
1565 }
1566 if (!virtio_device_ioeventfd_enabled(vdev)) {
1567 error_setg(errp, "ioeventfd is required for iothread");
1568 return false;
1569 }
1570
1571 /*
1572 * If ioeventfd is (re-)enabled while the guest is running there could
1573 * be block jobs that can conflict.
1574 */
1575 if (blk_op_is_blocked(conf->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
1576 error_prepend(errp, "cannot start virtio-blk ioeventfd: ");
1577 return false;
1578 }
1579 }
1580
1581 s->vq_aio_context = g_new(AioContext *, conf->num_queues);
1582
1583 if (conf->iothread_vq_mapping_list) {
1584 if (!apply_iothread_vq_mapping(conf->iothread_vq_mapping_list,
1585 s->vq_aio_context,
1586 conf->num_queues,
1587 errp)) {
1588 g_free(s->vq_aio_context);
1589 s->vq_aio_context = NULL;
1590 return false;
1591 }
1592 } else if (conf->iothread) {
1593 AioContext *ctx = iothread_get_aio_context(conf->iothread);
1594 for (unsigned i = 0; i < conf->num_queues; i++) {
1595 s->vq_aio_context[i] = ctx;
1596 }
1597
1598 /* Released in virtio_blk_vq_aio_context_cleanup() */
1599 object_ref(OBJECT(conf->iothread));
1600 } else {
1601 AioContext *ctx = qemu_get_aio_context();
1602 for (unsigned i = 0; i < conf->num_queues; i++) {
1603 s->vq_aio_context[i] = ctx;
1604 }
1605 }
1606
1607 return true;
1608 }
1609
1610 /* Context: BQL held */
virtio_blk_vq_aio_context_cleanup(VirtIOBlock * s)1611 static void virtio_blk_vq_aio_context_cleanup(VirtIOBlock *s)
1612 {
1613 VirtIOBlkConf *conf = &s->conf;
1614
1615 assert(!s->ioeventfd_started);
1616
1617 if (conf->iothread_vq_mapping_list) {
1618 IOThreadVirtQueueMappingList *node;
1619
1620 for (node = conf->iothread_vq_mapping_list; node; node = node->next) {
1621 IOThread *iothread = iothread_by_id(node->value->iothread);
1622 object_unref(OBJECT(iothread));
1623 }
1624 }
1625
1626 if (conf->iothread) {
1627 object_unref(OBJECT(conf->iothread));
1628 }
1629
1630 g_free(s->vq_aio_context);
1631 s->vq_aio_context = NULL;
1632 }
1633
1634 /* Context: BQL held */
virtio_blk_start_ioeventfd(VirtIODevice * vdev)1635 static int virtio_blk_start_ioeventfd(VirtIODevice *vdev)
1636 {
1637 VirtIOBlock *s = VIRTIO_BLK(vdev);
1638 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
1639 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
1640 unsigned i;
1641 unsigned nvqs = s->conf.num_queues;
1642 Error *local_err = NULL;
1643 int r;
1644
1645 if (s->ioeventfd_started || s->ioeventfd_starting) {
1646 return 0;
1647 }
1648
1649 s->ioeventfd_starting = true;
1650
1651 /* Set up guest notifier (irq) */
1652 r = k->set_guest_notifiers(qbus->parent, nvqs, true);
1653 if (r != 0) {
1654 error_report("virtio-blk failed to set guest notifier (%d), "
1655 "ensure -accel kvm is set.", r);
1656 goto fail_guest_notifiers;
1657 }
1658
1659 /*
1660 * Batch all the host notifiers in a single transaction to avoid
1661 * quadratic time complexity in address_space_update_ioeventfds().
1662 */
1663 memory_region_transaction_begin();
1664
1665 /* Set up virtqueue notify */
1666 for (i = 0; i < nvqs; i++) {
1667 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, true);
1668 if (r != 0) {
1669 int j = i;
1670
1671 fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
1672 while (i--) {
1673 virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
1674 }
1675
1676 /*
1677 * The transaction expects the ioeventfds to be open when it
1678 * commits. Do it now, before the cleanup loop.
1679 */
1680 memory_region_transaction_commit();
1681
1682 while (j--) {
1683 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), j);
1684 }
1685 goto fail_host_notifiers;
1686 }
1687 }
1688
1689 memory_region_transaction_commit();
1690
1691 /*
1692 * Try to change the AioContext so that block jobs and other operations can
1693 * co-locate their activity in the same AioContext. If it fails, nevermind.
1694 */
1695 assert(nvqs > 0); /* enforced during ->realize() */
1696 r = blk_set_aio_context(s->conf.conf.blk, s->vq_aio_context[0],
1697 &local_err);
1698 if (r < 0) {
1699 warn_report_err(local_err);
1700 }
1701
1702 /*
1703 * These fields must be visible to the IOThread when it processes the
1704 * virtqueue, otherwise it will think ioeventfd has not started yet.
1705 *
1706 * Make sure ->ioeventfd_started is false when blk_set_aio_context() is
1707 * called above so that draining does not cause the host notifier to be
1708 * detached/attached prematurely.
1709 */
1710 s->ioeventfd_starting = false;
1711 s->ioeventfd_started = true;
1712 smp_wmb(); /* paired with aio_notify_accept() on the read side */
1713
1714 /*
1715 * Get this show started by hooking up our callbacks. If drained now,
1716 * virtio_blk_drained_end() will do this later.
1717 * Attaching the notifier also kicks the virtqueues, processing any requests
1718 * they may already have.
1719 */
1720 if (!blk_in_drain(s->conf.conf.blk)) {
1721 virtio_blk_ioeventfd_attach(s);
1722 }
1723 return 0;
1724
1725 fail_host_notifiers:
1726 k->set_guest_notifiers(qbus->parent, nvqs, false);
1727 fail_guest_notifiers:
1728 s->ioeventfd_disabled = true;
1729 s->ioeventfd_starting = false;
1730 return -ENOSYS;
1731 }
1732
1733 /* Stop notifications for new requests from guest.
1734 *
1735 * Context: BH in IOThread
1736 */
virtio_blk_ioeventfd_stop_vq_bh(void * opaque)1737 static void virtio_blk_ioeventfd_stop_vq_bh(void *opaque)
1738 {
1739 VirtQueue *vq = opaque;
1740 EventNotifier *host_notifier = virtio_queue_get_host_notifier(vq);
1741
1742 virtio_queue_aio_detach_host_notifier(vq, qemu_get_current_aio_context());
1743
1744 /*
1745 * Test and clear notifier after disabling event, in case poll callback
1746 * didn't have time to run.
1747 */
1748 virtio_queue_host_notifier_read(host_notifier);
1749 }
1750
1751 /* Context: BQL held */
virtio_blk_stop_ioeventfd(VirtIODevice * vdev)1752 static void virtio_blk_stop_ioeventfd(VirtIODevice *vdev)
1753 {
1754 VirtIOBlock *s = VIRTIO_BLK(vdev);
1755 BusState *qbus = qdev_get_parent_bus(DEVICE(s));
1756 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
1757 unsigned i;
1758 unsigned nvqs = s->conf.num_queues;
1759
1760 if (!s->ioeventfd_started || s->ioeventfd_stopping) {
1761 return;
1762 }
1763
1764 /* Better luck next time. */
1765 if (s->ioeventfd_disabled) {
1766 s->ioeventfd_disabled = false;
1767 s->ioeventfd_started = false;
1768 return;
1769 }
1770 s->ioeventfd_stopping = true;
1771
1772 if (!blk_in_drain(s->conf.conf.blk)) {
1773 for (i = 0; i < nvqs; i++) {
1774 VirtQueue *vq = virtio_get_queue(vdev, i);
1775 AioContext *ctx = s->vq_aio_context[i];
1776
1777 aio_wait_bh_oneshot(ctx, virtio_blk_ioeventfd_stop_vq_bh, vq);
1778 }
1779 }
1780
1781 /*
1782 * Batch all the host notifiers in a single transaction to avoid
1783 * quadratic time complexity in address_space_update_ioeventfds().
1784 */
1785 memory_region_transaction_begin();
1786
1787 for (i = 0; i < nvqs; i++) {
1788 virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
1789 }
1790
1791 /*
1792 * The transaction expects the ioeventfds to be open when it
1793 * commits. Do it now, before the cleanup loop.
1794 */
1795 memory_region_transaction_commit();
1796
1797 for (i = 0; i < nvqs; i++) {
1798 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i);
1799 }
1800
1801 /*
1802 * Set ->ioeventfd_started to false before draining so that host notifiers
1803 * are not detached/attached anymore.
1804 */
1805 s->ioeventfd_started = false;
1806
1807 /* Wait for virtio_blk_dma_restart_bh() and in flight I/O to complete */
1808 blk_drain(s->conf.conf.blk);
1809
1810 /*
1811 * Try to switch bs back to the QEMU main loop. If other users keep the
1812 * BlockBackend in the iothread, that's ok
1813 */
1814 blk_set_aio_context(s->conf.conf.blk, qemu_get_aio_context(), NULL);
1815
1816 /* Clean up guest notifier (irq) */
1817 k->set_guest_notifiers(qbus->parent, nvqs, false);
1818
1819 s->ioeventfd_stopping = false;
1820 }
1821
virtio_blk_device_realize(DeviceState * dev,Error ** errp)1822 static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
1823 {
1824 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1825 VirtIOBlock *s = VIRTIO_BLK(dev);
1826 VirtIOBlkConf *conf = &s->conf;
1827 BlockDriverState *bs;
1828 Error *err = NULL;
1829 unsigned i;
1830
1831 if (!conf->conf.blk) {
1832 error_setg(errp, "drive property not set");
1833 return;
1834 }
1835 if (!blk_is_inserted(conf->conf.blk)) {
1836 error_setg(errp, "Device needs media, but drive is empty");
1837 return;
1838 }
1839 if (conf->num_queues == VIRTIO_BLK_AUTO_NUM_QUEUES) {
1840 conf->num_queues = 1;
1841 }
1842 if (!conf->num_queues) {
1843 error_setg(errp, "num-queues property must be larger than 0");
1844 return;
1845 }
1846 if (conf->queue_size <= 2) {
1847 error_setg(errp, "invalid queue-size property (%" PRIu16 "), "
1848 "must be > 2", conf->queue_size);
1849 return;
1850 }
1851 if (!is_power_of_2(conf->queue_size) ||
1852 conf->queue_size > VIRTQUEUE_MAX_SIZE) {
1853 error_setg(errp, "invalid queue-size property (%" PRIu16 "), "
1854 "must be a power of 2 (max %d)",
1855 conf->queue_size, VIRTQUEUE_MAX_SIZE);
1856 return;
1857 }
1858
1859 if (!blkconf_apply_backend_options(&conf->conf,
1860 !blk_supports_write_perm(conf->conf.blk),
1861 true, errp)) {
1862 return;
1863 }
1864 s->original_wce = blk_enable_write_cache(conf->conf.blk);
1865 if (!blkconf_geometry(&conf->conf, NULL, 65535, 255, 255, errp)) {
1866 return;
1867 }
1868
1869 if (!blkconf_blocksizes(&conf->conf, errp)) {
1870 return;
1871 }
1872
1873 bs = blk_bs(conf->conf.blk);
1874 if (bs->bl.zoned != BLK_Z_NONE) {
1875 virtio_add_feature(&s->host_features, VIRTIO_BLK_F_ZONED);
1876 if (bs->bl.zoned == BLK_Z_HM) {
1877 virtio_clear_feature(&s->host_features, VIRTIO_BLK_F_DISCARD);
1878 }
1879 }
1880
1881 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD) &&
1882 (!conf->max_discard_sectors ||
1883 conf->max_discard_sectors > BDRV_REQUEST_MAX_SECTORS)) {
1884 error_setg(errp, "invalid max-discard-sectors property (%" PRIu32 ")"
1885 ", must be between 1 and %d",
1886 conf->max_discard_sectors, (int)BDRV_REQUEST_MAX_SECTORS);
1887 return;
1888 }
1889
1890 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES) &&
1891 (!conf->max_write_zeroes_sectors ||
1892 conf->max_write_zeroes_sectors > BDRV_REQUEST_MAX_SECTORS)) {
1893 error_setg(errp, "invalid max-write-zeroes-sectors property (%" PRIu32
1894 "), must be between 1 and %d",
1895 conf->max_write_zeroes_sectors,
1896 (int)BDRV_REQUEST_MAX_SECTORS);
1897 return;
1898 }
1899
1900 s->config_size = virtio_get_config_size(&virtio_blk_cfg_size_params,
1901 s->host_features);
1902 virtio_init(vdev, VIRTIO_ID_BLOCK, s->config_size);
1903
1904 qemu_mutex_init(&s->rq_lock);
1905
1906 s->blk = conf->conf.blk;
1907 s->rq = NULL;
1908 s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1;
1909
1910 for (i = 0; i < conf->num_queues; i++) {
1911 virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output);
1912 }
1913 qemu_coroutine_inc_pool_size(conf->num_queues * conf->queue_size / 2);
1914
1915 /* Don't start ioeventfd if transport does not support notifiers. */
1916 if (!virtio_device_ioeventfd_enabled(vdev)) {
1917 s->ioeventfd_disabled = true;
1918 }
1919
1920 virtio_blk_vq_aio_context_init(s, &err);
1921 if (err != NULL) {
1922 error_propagate(errp, err);
1923 for (i = 0; i < conf->num_queues; i++) {
1924 virtio_del_queue(vdev, i);
1925 }
1926 virtio_cleanup(vdev);
1927 return;
1928 }
1929
1930 /*
1931 * This must be after virtio_init() so virtio_blk_dma_restart_cb() gets
1932 * called after ->start_ioeventfd() has already set blk's AioContext.
1933 */
1934 s->change =
1935 qdev_add_vm_change_state_handler(dev, virtio_blk_dma_restart_cb, s);
1936
1937 blk_ram_registrar_init(&s->blk_ram_registrar, s->blk);
1938 blk_set_dev_ops(s->blk, &virtio_block_ops, s);
1939
1940 blk_iostatus_enable(s->blk);
1941
1942 add_boot_device_lchs(dev, "/disk@0,0",
1943 conf->conf.lcyls,
1944 conf->conf.lheads,
1945 conf->conf.lsecs);
1946 }
1947
virtio_blk_device_unrealize(DeviceState * dev)1948 static void virtio_blk_device_unrealize(DeviceState *dev)
1949 {
1950 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1951 VirtIOBlock *s = VIRTIO_BLK(dev);
1952 VirtIOBlkConf *conf = &s->conf;
1953 unsigned i;
1954
1955 blk_drain(s->blk);
1956 del_boot_device_lchs(dev, "/disk@0,0");
1957 virtio_blk_vq_aio_context_cleanup(s);
1958 for (i = 0; i < conf->num_queues; i++) {
1959 virtio_del_queue(vdev, i);
1960 }
1961 qemu_coroutine_dec_pool_size(conf->num_queues * conf->queue_size / 2);
1962 qemu_mutex_destroy(&s->rq_lock);
1963 blk_ram_registrar_destroy(&s->blk_ram_registrar);
1964 qemu_del_vm_change_state_handler(s->change);
1965 blockdev_mark_auto_del(s->blk);
1966 virtio_cleanup(vdev);
1967 }
1968
virtio_blk_instance_init(Object * obj)1969 static void virtio_blk_instance_init(Object *obj)
1970 {
1971 VirtIOBlock *s = VIRTIO_BLK(obj);
1972
1973 device_add_bootindex_property(obj, &s->conf.conf.bootindex,
1974 "bootindex", "/disk@0,0",
1975 DEVICE(obj));
1976 }
1977
1978 static const VMStateDescription vmstate_virtio_blk = {
1979 .name = "virtio-blk",
1980 .minimum_version_id = 2,
1981 .version_id = 2,
1982 .fields = (const VMStateField[]) {
1983 VMSTATE_VIRTIO_DEVICE,
1984 VMSTATE_END_OF_LIST()
1985 },
1986 };
1987
1988 static Property virtio_blk_properties[] = {
1989 DEFINE_BLOCK_PROPERTIES(VirtIOBlock, conf.conf),
1990 DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock, conf.conf),
1991 DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, conf.conf),
1992 DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial),
1993 DEFINE_PROP_BIT64("config-wce", VirtIOBlock, host_features,
1994 VIRTIO_BLK_F_CONFIG_WCE, true),
1995 DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0,
1996 true),
1997 DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues,
1998 VIRTIO_BLK_AUTO_NUM_QUEUES),
1999 DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 256),
2000 DEFINE_PROP_BOOL("seg-max-adjust", VirtIOBlock, conf.seg_max_adjust, true),
2001 DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD,
2002 IOThread *),
2003 DEFINE_PROP_IOTHREAD_VQ_MAPPING_LIST("iothread-vq-mapping", VirtIOBlock,
2004 conf.iothread_vq_mapping_list),
2005 DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features,
2006 VIRTIO_BLK_F_DISCARD, true),
2007 DEFINE_PROP_BOOL("report-discard-granularity", VirtIOBlock,
2008 conf.report_discard_granularity, true),
2009 DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock, host_features,
2010 VIRTIO_BLK_F_WRITE_ZEROES, true),
2011 DEFINE_PROP_UINT32("max-discard-sectors", VirtIOBlock,
2012 conf.max_discard_sectors, BDRV_REQUEST_MAX_SECTORS),
2013 DEFINE_PROP_UINT32("max-write-zeroes-sectors", VirtIOBlock,
2014 conf.max_write_zeroes_sectors, BDRV_REQUEST_MAX_SECTORS),
2015 DEFINE_PROP_BOOL("x-enable-wce-if-config-wce", VirtIOBlock,
2016 conf.x_enable_wce_if_config_wce, true),
2017 DEFINE_PROP_END_OF_LIST(),
2018 };
2019
virtio_blk_class_init(ObjectClass * klass,void * data)2020 static void virtio_blk_class_init(ObjectClass *klass, void *data)
2021 {
2022 DeviceClass *dc = DEVICE_CLASS(klass);
2023 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
2024
2025 device_class_set_props(dc, virtio_blk_properties);
2026 dc->vmsd = &vmstate_virtio_blk;
2027 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
2028 vdc->realize = virtio_blk_device_realize;
2029 vdc->unrealize = virtio_blk_device_unrealize;
2030 vdc->get_config = virtio_blk_update_config;
2031 vdc->set_config = virtio_blk_set_config;
2032 vdc->get_features = virtio_blk_get_features;
2033 vdc->set_status = virtio_blk_set_status;
2034 vdc->reset = virtio_blk_reset;
2035 vdc->save = virtio_blk_save_device;
2036 vdc->load = virtio_blk_load_device;
2037 vdc->start_ioeventfd = virtio_blk_start_ioeventfd;
2038 vdc->stop_ioeventfd = virtio_blk_stop_ioeventfd;
2039 }
2040
2041 static const TypeInfo virtio_blk_info = {
2042 .name = TYPE_VIRTIO_BLK,
2043 .parent = TYPE_VIRTIO_DEVICE,
2044 .instance_size = sizeof(VirtIOBlock),
2045 .instance_init = virtio_blk_instance_init,
2046 .class_init = virtio_blk_class_init,
2047 };
2048
virtio_register_types(void)2049 static void virtio_register_types(void)
2050 {
2051 type_register_static(&virtio_blk_info);
2052 }
2053
2054 type_init(virtio_register_types)
2055