travis: stop using container based envs
[qemu/ar7.git] / hw / block / virtio-blk.c
blobf208c6ddb93488e809bd88d7fac4f8107f9bd6e1
1 /*
2 * Virtio Block Device
4 * Copyright IBM, Corp. 2007
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
14 #include "qemu/osdep.h"
15 #include "qapi/error.h"
16 #include "qemu-common.h"
17 #include "qemu/iov.h"
18 #include "qemu/error-report.h"
19 #include "trace.h"
20 #include "hw/block/block.h"
21 #include "sysemu/blockdev.h"
22 #include "hw/virtio/virtio-blk.h"
23 #include "dataplane/virtio-blk.h"
24 #include "scsi/constants.h"
25 #ifdef __linux__
26 # include <scsi/sg.h>
27 #endif
28 #include "hw/virtio/virtio-bus.h"
29 #include "hw/virtio/virtio-access.h"
31 static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
32 VirtIOBlockReq *req)
34 req->dev = s;
35 req->vq = vq;
36 req->qiov.size = 0;
37 req->in_len = 0;
38 req->next = NULL;
39 req->mr_next = NULL;
42 static void virtio_blk_free_request(VirtIOBlockReq *req)
44 g_free(req);
47 static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status)
49 VirtIOBlock *s = req->dev;
50 VirtIODevice *vdev = VIRTIO_DEVICE(s);
52 trace_virtio_blk_req_complete(vdev, req, status);
54 stb_p(&req->in->status, status);
55 virtqueue_push(req->vq, &req->elem, req->in_len);
56 if (s->dataplane_started && !s->dataplane_disabled) {
57 virtio_blk_data_plane_notify(s->dataplane, req->vq);
58 } else {
59 virtio_notify(vdev, req->vq);
63 static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
64 bool is_read)
66 BlockErrorAction action = blk_get_error_action(req->dev->blk,
67 is_read, error);
68 VirtIOBlock *s = req->dev;
70 if (action == BLOCK_ERROR_ACTION_STOP) {
71 /* Break the link as the next request is going to be parsed from the
72 * ring again. Otherwise we may end up doing a double completion! */
73 req->mr_next = NULL;
74 req->next = s->rq;
75 s->rq = req;
76 } else if (action == BLOCK_ERROR_ACTION_REPORT) {
77 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
78 block_acct_failed(blk_get_stats(s->blk), &req->acct);
79 virtio_blk_free_request(req);
82 blk_error_action(s->blk, action, is_read, error);
83 return action != BLOCK_ERROR_ACTION_IGNORE;
86 static void virtio_blk_rw_complete(void *opaque, int ret)
88 VirtIOBlockReq *next = opaque;
89 VirtIOBlock *s = next->dev;
90 VirtIODevice *vdev = VIRTIO_DEVICE(s);
92 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
93 while (next) {
94 VirtIOBlockReq *req = next;
95 next = req->mr_next;
96 trace_virtio_blk_rw_complete(vdev, req, ret);
98 if (req->qiov.nalloc != -1) {
99 /* If nalloc is != -1 req->qiov is a local copy of the original
100 * external iovec. It was allocated in submit_requests to be
101 * able to merge requests. */
102 qemu_iovec_destroy(&req->qiov);
105 if (ret) {
106 int p = virtio_ldl_p(VIRTIO_DEVICE(req->dev), &req->out.type);
107 bool is_read = !(p & VIRTIO_BLK_T_OUT);
108 /* Note that memory may be dirtied on read failure. If the
109 * virtio request is not completed here, as is the case for
110 * BLOCK_ERROR_ACTION_STOP, the memory may not be copied
111 * correctly during live migration. While this is ugly,
112 * it is acceptable because the device is free to write to
113 * the memory until the request is completed (which will
114 * happen on the other side of the migration).
116 if (virtio_blk_handle_rw_error(req, -ret, is_read)) {
117 continue;
121 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
122 block_acct_done(blk_get_stats(req->dev->blk), &req->acct);
123 virtio_blk_free_request(req);
125 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
128 static void virtio_blk_flush_complete(void *opaque, int ret)
130 VirtIOBlockReq *req = opaque;
131 VirtIOBlock *s = req->dev;
133 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
134 if (ret) {
135 if (virtio_blk_handle_rw_error(req, -ret, 0)) {
136 goto out;
140 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
141 block_acct_done(blk_get_stats(req->dev->blk), &req->acct);
142 virtio_blk_free_request(req);
144 out:
145 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
148 #ifdef __linux__
150 typedef struct {
151 VirtIOBlockReq *req;
152 struct sg_io_hdr hdr;
153 } VirtIOBlockIoctlReq;
155 static void virtio_blk_ioctl_complete(void *opaque, int status)
157 VirtIOBlockIoctlReq *ioctl_req = opaque;
158 VirtIOBlockReq *req = ioctl_req->req;
159 VirtIOBlock *s = req->dev;
160 VirtIODevice *vdev = VIRTIO_DEVICE(s);
161 struct virtio_scsi_inhdr *scsi;
162 struct sg_io_hdr *hdr;
164 scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base;
166 if (status) {
167 status = VIRTIO_BLK_S_UNSUPP;
168 virtio_stl_p(vdev, &scsi->errors, 255);
169 goto out;
172 hdr = &ioctl_req->hdr;
174 * From SCSI-Generic-HOWTO: "Some lower level drivers (e.g. ide-scsi)
175 * clear the masked_status field [hence status gets cleared too, see
176 * block/scsi_ioctl.c] even when a CHECK_CONDITION or COMMAND_TERMINATED
177 * status has occurred. However they do set DRIVER_SENSE in driver_status
178 * field. Also a (sb_len_wr > 0) indicates there is a sense buffer.
180 if (hdr->status == 0 && hdr->sb_len_wr > 0) {
181 hdr->status = CHECK_CONDITION;
184 virtio_stl_p(vdev, &scsi->errors,
185 hdr->status | (hdr->msg_status << 8) |
186 (hdr->host_status << 16) | (hdr->driver_status << 24));
187 virtio_stl_p(vdev, &scsi->residual, hdr->resid);
188 virtio_stl_p(vdev, &scsi->sense_len, hdr->sb_len_wr);
189 virtio_stl_p(vdev, &scsi->data_len, hdr->dxfer_len);
191 out:
192 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
193 virtio_blk_req_complete(req, status);
194 virtio_blk_free_request(req);
195 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
196 g_free(ioctl_req);
199 #endif
201 static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s, VirtQueue *vq)
203 VirtIOBlockReq *req = virtqueue_pop(vq, sizeof(VirtIOBlockReq));
205 if (req) {
206 virtio_blk_init_request(s, vq, req);
208 return req;
211 static int virtio_blk_handle_scsi_req(VirtIOBlockReq *req)
213 int status = VIRTIO_BLK_S_OK;
214 struct virtio_scsi_inhdr *scsi = NULL;
215 VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
216 VirtQueueElement *elem = &req->elem;
217 VirtIOBlock *blk = req->dev;
219 #ifdef __linux__
220 int i;
221 VirtIOBlockIoctlReq *ioctl_req;
222 BlockAIOCB *acb;
223 #endif
226 * We require at least one output segment each for the virtio_blk_outhdr
227 * and the SCSI command block.
229 * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr
230 * and the sense buffer pointer in the input segments.
232 if (elem->out_num < 2 || elem->in_num < 3) {
233 status = VIRTIO_BLK_S_IOERR;
234 goto fail;
238 * The scsi inhdr is placed in the second-to-last input segment, just
239 * before the regular inhdr.
241 scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base;
243 if (!blk->conf.scsi) {
244 status = VIRTIO_BLK_S_UNSUPP;
245 goto fail;
249 * No support for bidirection commands yet.
251 if (elem->out_num > 2 && elem->in_num > 3) {
252 status = VIRTIO_BLK_S_UNSUPP;
253 goto fail;
256 #ifdef __linux__
257 ioctl_req = g_new0(VirtIOBlockIoctlReq, 1);
258 ioctl_req->req = req;
259 ioctl_req->hdr.interface_id = 'S';
260 ioctl_req->hdr.cmd_len = elem->out_sg[1].iov_len;
261 ioctl_req->hdr.cmdp = elem->out_sg[1].iov_base;
262 ioctl_req->hdr.dxfer_len = 0;
264 if (elem->out_num > 2) {
266 * If there are more than the minimally required 2 output segments
267 * there is write payload starting from the third iovec.
269 ioctl_req->hdr.dxfer_direction = SG_DXFER_TO_DEV;
270 ioctl_req->hdr.iovec_count = elem->out_num - 2;
272 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) {
273 ioctl_req->hdr.dxfer_len += elem->out_sg[i + 2].iov_len;
276 ioctl_req->hdr.dxferp = elem->out_sg + 2;
278 } else if (elem->in_num > 3) {
280 * If we have more than 3 input segments the guest wants to actually
281 * read data.
283 ioctl_req->hdr.dxfer_direction = SG_DXFER_FROM_DEV;
284 ioctl_req->hdr.iovec_count = elem->in_num - 3;
285 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) {
286 ioctl_req->hdr.dxfer_len += elem->in_sg[i].iov_len;
289 ioctl_req->hdr.dxferp = elem->in_sg;
290 } else {
292 * Some SCSI commands don't actually transfer any data.
294 ioctl_req->hdr.dxfer_direction = SG_DXFER_NONE;
297 ioctl_req->hdr.sbp = elem->in_sg[elem->in_num - 3].iov_base;
298 ioctl_req->hdr.mx_sb_len = elem->in_sg[elem->in_num - 3].iov_len;
300 acb = blk_aio_ioctl(blk->blk, SG_IO, &ioctl_req->hdr,
301 virtio_blk_ioctl_complete, ioctl_req);
302 if (!acb) {
303 g_free(ioctl_req);
304 status = VIRTIO_BLK_S_UNSUPP;
305 goto fail;
307 return -EINPROGRESS;
308 #else
309 abort();
310 #endif
312 fail:
313 /* Just put anything nonzero so that the ioctl fails in the guest. */
314 if (scsi) {
315 virtio_stl_p(vdev, &scsi->errors, 255);
317 return status;
320 static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
322 int status;
324 status = virtio_blk_handle_scsi_req(req);
325 if (status != -EINPROGRESS) {
326 virtio_blk_req_complete(req, status);
327 virtio_blk_free_request(req);
331 static inline void submit_requests(BlockBackend *blk, MultiReqBuffer *mrb,
332 int start, int num_reqs, int niov)
334 QEMUIOVector *qiov = &mrb->reqs[start]->qiov;
335 int64_t sector_num = mrb->reqs[start]->sector_num;
336 bool is_write = mrb->is_write;
338 if (num_reqs > 1) {
339 int i;
340 struct iovec *tmp_iov = qiov->iov;
341 int tmp_niov = qiov->niov;
343 /* mrb->reqs[start]->qiov was initialized from external so we can't
344 * modify it here. We need to initialize it locally and then add the
345 * external iovecs. */
346 qemu_iovec_init(qiov, niov);
348 for (i = 0; i < tmp_niov; i++) {
349 qemu_iovec_add(qiov, tmp_iov[i].iov_base, tmp_iov[i].iov_len);
352 for (i = start + 1; i < start + num_reqs; i++) {
353 qemu_iovec_concat(qiov, &mrb->reqs[i]->qiov, 0,
354 mrb->reqs[i]->qiov.size);
355 mrb->reqs[i - 1]->mr_next = mrb->reqs[i];
358 trace_virtio_blk_submit_multireq(VIRTIO_DEVICE(mrb->reqs[start]->dev),
359 mrb, start, num_reqs,
360 sector_num << BDRV_SECTOR_BITS,
361 qiov->size, is_write);
362 block_acct_merge_done(blk_get_stats(blk),
363 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ,
364 num_reqs - 1);
367 if (is_write) {
368 blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0,
369 virtio_blk_rw_complete, mrb->reqs[start]);
370 } else {
371 blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0,
372 virtio_blk_rw_complete, mrb->reqs[start]);
376 static int multireq_compare(const void *a, const void *b)
378 const VirtIOBlockReq *req1 = *(VirtIOBlockReq **)a,
379 *req2 = *(VirtIOBlockReq **)b;
382 * Note that we can't simply subtract sector_num1 from sector_num2
383 * here as that could overflow the return value.
385 if (req1->sector_num > req2->sector_num) {
386 return 1;
387 } else if (req1->sector_num < req2->sector_num) {
388 return -1;
389 } else {
390 return 0;
394 static void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb)
396 int i = 0, start = 0, num_reqs = 0, niov = 0, nb_sectors = 0;
397 uint32_t max_transfer;
398 int64_t sector_num = 0;
400 if (mrb->num_reqs == 1) {
401 submit_requests(blk, mrb, 0, 1, -1);
402 mrb->num_reqs = 0;
403 return;
406 max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk);
408 qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs),
409 &multireq_compare);
411 for (i = 0; i < mrb->num_reqs; i++) {
412 VirtIOBlockReq *req = mrb->reqs[i];
413 if (num_reqs > 0) {
415 * NOTE: We cannot merge the requests in below situations:
416 * 1. requests are not sequential
417 * 2. merge would exceed maximum number of IOVs
418 * 3. merge would exceed maximum transfer length of backend device
420 if (sector_num + nb_sectors != req->sector_num ||
421 niov > blk_get_max_iov(blk) - req->qiov.niov ||
422 req->qiov.size > max_transfer ||
423 nb_sectors > (max_transfer -
424 req->qiov.size) / BDRV_SECTOR_SIZE) {
425 submit_requests(blk, mrb, start, num_reqs, niov);
426 num_reqs = 0;
430 if (num_reqs == 0) {
431 sector_num = req->sector_num;
432 nb_sectors = niov = 0;
433 start = i;
436 nb_sectors += req->qiov.size / BDRV_SECTOR_SIZE;
437 niov += req->qiov.niov;
438 num_reqs++;
441 submit_requests(blk, mrb, start, num_reqs, niov);
442 mrb->num_reqs = 0;
445 static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb)
447 block_acct_start(blk_get_stats(req->dev->blk), &req->acct, 0,
448 BLOCK_ACCT_FLUSH);
451 * Make sure all outstanding writes are posted to the backing device.
453 if (mrb->is_write && mrb->num_reqs > 0) {
454 virtio_blk_submit_multireq(req->dev->blk, mrb);
456 blk_aio_flush(req->dev->blk, virtio_blk_flush_complete, req);
459 static bool virtio_blk_sect_range_ok(VirtIOBlock *dev,
460 uint64_t sector, size_t size)
462 uint64_t nb_sectors = size >> BDRV_SECTOR_BITS;
463 uint64_t total_sectors;
465 if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
466 return false;
468 if (sector & dev->sector_mask) {
469 return false;
471 if (size % dev->conf.conf.logical_block_size) {
472 return false;
474 blk_get_geometry(dev->blk, &total_sectors);
475 if (sector > total_sectors || nb_sectors > total_sectors - sector) {
476 return false;
478 return true;
481 static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
483 uint32_t type;
484 struct iovec *in_iov = req->elem.in_sg;
485 struct iovec *out_iov = req->elem.out_sg;
486 unsigned in_num = req->elem.in_num;
487 unsigned out_num = req->elem.out_num;
488 VirtIOBlock *s = req->dev;
489 VirtIODevice *vdev = VIRTIO_DEVICE(s);
491 if (req->elem.out_num < 1 || req->elem.in_num < 1) {
492 virtio_error(vdev, "virtio-blk missing headers");
493 return -1;
496 if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
497 sizeof(req->out)) != sizeof(req->out))) {
498 virtio_error(vdev, "virtio-blk request outhdr too short");
499 return -1;
502 iov_discard_front(&out_iov, &out_num, sizeof(req->out));
504 if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
505 virtio_error(vdev, "virtio-blk request inhdr too short");
506 return -1;
509 /* We always touch the last byte, so just see how big in_iov is. */
510 req->in_len = iov_size(in_iov, in_num);
511 req->in = (void *)in_iov[in_num - 1].iov_base
512 + in_iov[in_num - 1].iov_len
513 - sizeof(struct virtio_blk_inhdr);
514 iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr));
516 type = virtio_ldl_p(VIRTIO_DEVICE(req->dev), &req->out.type);
518 /* VIRTIO_BLK_T_OUT defines the command direction. VIRTIO_BLK_T_BARRIER
519 * is an optional flag. Although a guest should not send this flag if
520 * not negotiated we ignored it in the past. So keep ignoring it. */
521 switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) {
522 case VIRTIO_BLK_T_IN:
524 bool is_write = type & VIRTIO_BLK_T_OUT;
525 req->sector_num = virtio_ldq_p(VIRTIO_DEVICE(req->dev),
526 &req->out.sector);
528 if (is_write) {
529 qemu_iovec_init_external(&req->qiov, out_iov, out_num);
530 trace_virtio_blk_handle_write(vdev, req, req->sector_num,
531 req->qiov.size / BDRV_SECTOR_SIZE);
532 } else {
533 qemu_iovec_init_external(&req->qiov, in_iov, in_num);
534 trace_virtio_blk_handle_read(vdev, req, req->sector_num,
535 req->qiov.size / BDRV_SECTOR_SIZE);
538 if (!virtio_blk_sect_range_ok(req->dev, req->sector_num,
539 req->qiov.size)) {
540 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
541 block_acct_invalid(blk_get_stats(req->dev->blk),
542 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
543 virtio_blk_free_request(req);
544 return 0;
547 block_acct_start(blk_get_stats(req->dev->blk),
548 &req->acct, req->qiov.size,
549 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
551 /* merge would exceed maximum number of requests or IO direction
552 * changes */
553 if (mrb->num_reqs > 0 && (mrb->num_reqs == VIRTIO_BLK_MAX_MERGE_REQS ||
554 is_write != mrb->is_write ||
555 !req->dev->conf.request_merging)) {
556 virtio_blk_submit_multireq(req->dev->blk, mrb);
559 assert(mrb->num_reqs < VIRTIO_BLK_MAX_MERGE_REQS);
560 mrb->reqs[mrb->num_reqs++] = req;
561 mrb->is_write = is_write;
562 break;
564 case VIRTIO_BLK_T_FLUSH:
565 virtio_blk_handle_flush(req, mrb);
566 break;
567 case VIRTIO_BLK_T_SCSI_CMD:
568 virtio_blk_handle_scsi(req);
569 break;
570 case VIRTIO_BLK_T_GET_ID:
572 VirtIOBlock *s = req->dev;
575 * NB: per existing s/n string convention the string is
576 * terminated by '\0' only when shorter than buffer.
578 const char *serial = s->conf.serial ? s->conf.serial : "";
579 size_t size = MIN(strlen(serial) + 1,
580 MIN(iov_size(in_iov, in_num),
581 VIRTIO_BLK_ID_BYTES));
582 iov_from_buf(in_iov, in_num, 0, serial, size);
583 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
584 virtio_blk_free_request(req);
585 break;
587 default:
588 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
589 virtio_blk_free_request(req);
591 return 0;
594 bool virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq)
596 VirtIOBlockReq *req;
597 MultiReqBuffer mrb = {};
598 bool progress = false;
600 aio_context_acquire(blk_get_aio_context(s->blk));
601 blk_io_plug(s->blk);
603 do {
604 virtio_queue_set_notification(vq, 0);
606 while ((req = virtio_blk_get_request(s, vq))) {
607 progress = true;
608 if (virtio_blk_handle_request(req, &mrb)) {
609 virtqueue_detach_element(req->vq, &req->elem, 0);
610 virtio_blk_free_request(req);
611 break;
615 virtio_queue_set_notification(vq, 1);
616 } while (!virtio_queue_empty(vq));
618 if (mrb.num_reqs) {
619 virtio_blk_submit_multireq(s->blk, &mrb);
622 blk_io_unplug(s->blk);
623 aio_context_release(blk_get_aio_context(s->blk));
624 return progress;
627 static void virtio_blk_handle_output_do(VirtIOBlock *s, VirtQueue *vq)
629 virtio_blk_handle_vq(s, vq);
632 static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
634 VirtIOBlock *s = (VirtIOBlock *)vdev;
636 if (s->dataplane) {
637 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
638 * dataplane here instead of waiting for .set_status().
640 virtio_device_start_ioeventfd(vdev);
641 if (!s->dataplane_disabled) {
642 return;
645 virtio_blk_handle_output_do(s, vq);
648 static void virtio_blk_dma_restart_bh(void *opaque)
650 VirtIOBlock *s = opaque;
651 VirtIOBlockReq *req = s->rq;
652 MultiReqBuffer mrb = {};
654 qemu_bh_delete(s->bh);
655 s->bh = NULL;
657 s->rq = NULL;
659 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk));
660 while (req) {
661 VirtIOBlockReq *next = req->next;
662 if (virtio_blk_handle_request(req, &mrb)) {
663 /* Device is now broken and won't do any processing until it gets
664 * reset. Already queued requests will be lost: let's purge them.
666 while (req) {
667 next = req->next;
668 virtqueue_detach_element(req->vq, &req->elem, 0);
669 virtio_blk_free_request(req);
670 req = next;
672 break;
674 req = next;
677 if (mrb.num_reqs) {
678 virtio_blk_submit_multireq(s->blk, &mrb);
680 aio_context_release(blk_get_aio_context(s->conf.conf.blk));
683 static void virtio_blk_dma_restart_cb(void *opaque, int running,
684 RunState state)
686 VirtIOBlock *s = opaque;
688 if (!running) {
689 return;
692 if (!s->bh) {
693 s->bh = aio_bh_new(blk_get_aio_context(s->conf.conf.blk),
694 virtio_blk_dma_restart_bh, s);
695 qemu_bh_schedule(s->bh);
699 static void virtio_blk_reset(VirtIODevice *vdev)
701 VirtIOBlock *s = VIRTIO_BLK(vdev);
702 AioContext *ctx;
703 VirtIOBlockReq *req;
705 ctx = blk_get_aio_context(s->blk);
706 aio_context_acquire(ctx);
707 blk_drain(s->blk);
709 /* We drop queued requests after blk_drain() because blk_drain() itself can
710 * produce them. */
711 while (s->rq) {
712 req = s->rq;
713 s->rq = req->next;
714 virtqueue_detach_element(req->vq, &req->elem, 0);
715 virtio_blk_free_request(req);
718 aio_context_release(ctx);
720 assert(!s->dataplane_started);
721 blk_set_enable_write_cache(s->blk, s->original_wce);
724 /* coalesce internal state, copy to pci i/o region 0
726 static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
728 VirtIOBlock *s = VIRTIO_BLK(vdev);
729 BlockConf *conf = &s->conf.conf;
730 struct virtio_blk_config blkcfg;
731 uint64_t capacity;
732 int64_t length;
733 int blk_size = conf->logical_block_size;
735 blk_get_geometry(s->blk, &capacity);
736 memset(&blkcfg, 0, sizeof(blkcfg));
737 virtio_stq_p(vdev, &blkcfg.capacity, capacity);
738 virtio_stl_p(vdev, &blkcfg.seg_max, 128 - 2);
739 virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls);
740 virtio_stl_p(vdev, &blkcfg.blk_size, blk_size);
741 virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size);
742 virtio_stw_p(vdev, &blkcfg.opt_io_size, conf->opt_io_size / blk_size);
743 blkcfg.geometry.heads = conf->heads;
745 * We must ensure that the block device capacity is a multiple of
746 * the logical block size. If that is not the case, let's use
747 * sector_mask to adopt the geometry to have a correct picture.
748 * For those devices where the capacity is ok for the given geometry
749 * we don't touch the sector value of the geometry, since some devices
750 * (like s390 dasd) need a specific value. Here the capacity is already
751 * cyls*heads*secs*blk_size and the sector value is not block size
752 * divided by 512 - instead it is the amount of blk_size blocks
753 * per track (cylinder).
755 length = blk_getlength(s->blk);
756 if (length > 0 && length / conf->heads / conf->secs % blk_size) {
757 blkcfg.geometry.sectors = conf->secs & ~s->sector_mask;
758 } else {
759 blkcfg.geometry.sectors = conf->secs;
761 blkcfg.size_max = 0;
762 blkcfg.physical_block_exp = get_physical_block_exp(conf);
763 blkcfg.alignment_offset = 0;
764 blkcfg.wce = blk_enable_write_cache(s->blk);
765 virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues);
766 memcpy(config, &blkcfg, sizeof(struct virtio_blk_config));
769 static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
771 VirtIOBlock *s = VIRTIO_BLK(vdev);
772 struct virtio_blk_config blkcfg;
774 memcpy(&blkcfg, config, sizeof(blkcfg));
776 aio_context_acquire(blk_get_aio_context(s->blk));
777 blk_set_enable_write_cache(s->blk, blkcfg.wce != 0);
778 aio_context_release(blk_get_aio_context(s->blk));
781 static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features,
782 Error **errp)
784 VirtIOBlock *s = VIRTIO_BLK(vdev);
786 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
787 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
788 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
789 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
790 if (virtio_has_feature(features, VIRTIO_F_VERSION_1)) {
791 if (s->conf.scsi) {
792 error_setg(errp, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0");
793 return 0;
795 } else {
796 virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT);
797 virtio_add_feature(&features, VIRTIO_BLK_F_SCSI);
800 if (s->conf.config_wce) {
801 virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE);
803 if (blk_enable_write_cache(s->blk)) {
804 virtio_add_feature(&features, VIRTIO_BLK_F_WCE);
806 if (blk_is_read_only(s->blk)) {
807 virtio_add_feature(&features, VIRTIO_BLK_F_RO);
809 if (s->conf.num_queues > 1) {
810 virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
813 return features;
816 static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
818 VirtIOBlock *s = VIRTIO_BLK(vdev);
820 if (!(status & (VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK))) {
821 assert(!s->dataplane_started);
824 if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
825 return;
828 /* A guest that supports VIRTIO_BLK_F_CONFIG_WCE must be able to send
829 * cache flushes. Thus, the "auto writethrough" behavior is never
830 * necessary for guests that support the VIRTIO_BLK_F_CONFIG_WCE feature.
831 * Leaving it enabled would break the following sequence:
833 * Guest started with "-drive cache=writethrough"
834 * Guest sets status to 0
835 * Guest sets DRIVER bit in status field
836 * Guest reads host features (WCE=0, CONFIG_WCE=1)
837 * Guest writes guest features (WCE=0, CONFIG_WCE=1)
838 * Guest writes 1 to the WCE configuration field (writeback mode)
839 * Guest sets DRIVER_OK bit in status field
841 * s->blk would erroneously be placed in writethrough mode.
843 if (!virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) {
844 aio_context_acquire(blk_get_aio_context(s->blk));
845 blk_set_enable_write_cache(s->blk,
846 virtio_vdev_has_feature(vdev,
847 VIRTIO_BLK_F_WCE));
848 aio_context_release(blk_get_aio_context(s->blk));
852 static void virtio_blk_save_device(VirtIODevice *vdev, QEMUFile *f)
854 VirtIOBlock *s = VIRTIO_BLK(vdev);
855 VirtIOBlockReq *req = s->rq;
857 while (req) {
858 qemu_put_sbyte(f, 1);
860 if (s->conf.num_queues > 1) {
861 qemu_put_be32(f, virtio_get_queue_index(req->vq));
864 qemu_put_virtqueue_element(f, &req->elem);
865 req = req->next;
867 qemu_put_sbyte(f, 0);
870 static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f,
871 int version_id)
873 VirtIOBlock *s = VIRTIO_BLK(vdev);
875 while (qemu_get_sbyte(f)) {
876 unsigned nvqs = s->conf.num_queues;
877 unsigned vq_idx = 0;
878 VirtIOBlockReq *req;
880 if (nvqs > 1) {
881 vq_idx = qemu_get_be32(f);
883 if (vq_idx >= nvqs) {
884 error_report("Invalid virtqueue index in request list: %#x",
885 vq_idx);
886 return -EINVAL;
890 req = qemu_get_virtqueue_element(vdev, f, sizeof(VirtIOBlockReq));
891 virtio_blk_init_request(s, virtio_get_queue(vdev, vq_idx), req);
892 req->next = s->rq;
893 s->rq = req;
896 return 0;
899 static void virtio_blk_resize(void *opaque)
901 VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
903 virtio_notify_config(vdev);
906 static const BlockDevOps virtio_block_ops = {
907 .resize_cb = virtio_blk_resize,
910 static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
912 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
913 VirtIOBlock *s = VIRTIO_BLK(dev);
914 VirtIOBlkConf *conf = &s->conf;
915 Error *err = NULL;
916 unsigned i;
918 if (!conf->conf.blk) {
919 error_setg(errp, "drive property not set");
920 return;
922 if (!blk_is_inserted(conf->conf.blk)) {
923 error_setg(errp, "Device needs media, but drive is empty");
924 return;
926 if (!conf->num_queues) {
927 error_setg(errp, "num-queues property must be larger than 0");
928 return;
930 if (!is_power_of_2(conf->queue_size) ||
931 conf->queue_size > VIRTQUEUE_MAX_SIZE) {
932 error_setg(errp, "invalid queue-size property (%" PRIu16 "), "
933 "must be a power of 2 (max %d)",
934 conf->queue_size, VIRTQUEUE_MAX_SIZE);
935 return;
938 if (!blkconf_apply_backend_options(&conf->conf,
939 blk_is_read_only(conf->conf.blk), true,
940 errp)) {
941 return;
943 s->original_wce = blk_enable_write_cache(conf->conf.blk);
944 if (!blkconf_geometry(&conf->conf, NULL, 65535, 255, 255, errp)) {
945 return;
948 blkconf_blocksizes(&conf->conf);
950 if (conf->conf.logical_block_size >
951 conf->conf.physical_block_size) {
952 error_setg(errp,
953 "logical_block_size > physical_block_size not supported");
954 return;
957 virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
958 sizeof(struct virtio_blk_config));
960 s->blk = conf->conf.blk;
961 s->rq = NULL;
962 s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1;
964 for (i = 0; i < conf->num_queues; i++) {
965 virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output);
967 virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err);
968 if (err != NULL) {
969 error_propagate(errp, err);
970 virtio_cleanup(vdev);
971 return;
974 s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
975 blk_set_dev_ops(s->blk, &virtio_block_ops, s);
976 blk_set_guest_block_size(s->blk, s->conf.conf.logical_block_size);
978 blk_iostatus_enable(s->blk);
981 static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp)
983 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
984 VirtIOBlock *s = VIRTIO_BLK(dev);
986 virtio_blk_data_plane_destroy(s->dataplane);
987 s->dataplane = NULL;
988 qemu_del_vm_change_state_handler(s->change);
989 blockdev_mark_auto_del(s->blk);
990 virtio_cleanup(vdev);
993 static void virtio_blk_instance_init(Object *obj)
995 VirtIOBlock *s = VIRTIO_BLK(obj);
997 device_add_bootindex_property(obj, &s->conf.conf.bootindex,
998 "bootindex", "/disk@0,0",
999 DEVICE(obj), NULL);
1002 static const VMStateDescription vmstate_virtio_blk = {
1003 .name = "virtio-blk",
1004 .minimum_version_id = 2,
1005 .version_id = 2,
1006 .fields = (VMStateField[]) {
1007 VMSTATE_VIRTIO_DEVICE,
1008 VMSTATE_END_OF_LIST()
1012 static Property virtio_blk_properties[] = {
1013 DEFINE_BLOCK_PROPERTIES(VirtIOBlock, conf.conf),
1014 DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock, conf.conf),
1015 DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, conf.conf),
1016 DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial),
1017 DEFINE_PROP_BIT("config-wce", VirtIOBlock, conf.config_wce, 0, true),
1018 #ifdef __linux__
1019 DEFINE_PROP_BIT("scsi", VirtIOBlock, conf.scsi, 0, false),
1020 #endif
1021 DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0,
1022 true),
1023 DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues, 1),
1024 DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 128),
1025 DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD,
1026 IOThread *),
1027 DEFINE_PROP_END_OF_LIST(),
1030 static void virtio_blk_class_init(ObjectClass *klass, void *data)
1032 DeviceClass *dc = DEVICE_CLASS(klass);
1033 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1035 dc->props = virtio_blk_properties;
1036 dc->vmsd = &vmstate_virtio_blk;
1037 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
1038 vdc->realize = virtio_blk_device_realize;
1039 vdc->unrealize = virtio_blk_device_unrealize;
1040 vdc->get_config = virtio_blk_update_config;
1041 vdc->set_config = virtio_blk_set_config;
1042 vdc->get_features = virtio_blk_get_features;
1043 vdc->set_status = virtio_blk_set_status;
1044 vdc->reset = virtio_blk_reset;
1045 vdc->save = virtio_blk_save_device;
1046 vdc->load = virtio_blk_load_device;
1047 vdc->start_ioeventfd = virtio_blk_data_plane_start;
1048 vdc->stop_ioeventfd = virtio_blk_data_plane_stop;
1051 static const TypeInfo virtio_blk_info = {
1052 .name = TYPE_VIRTIO_BLK,
1053 .parent = TYPE_VIRTIO_DEVICE,
1054 .instance_size = sizeof(VirtIOBlock),
1055 .instance_init = virtio_blk_instance_init,
1056 .class_init = virtio_blk_class_init,
1059 static void virtio_register_types(void)
1061 type_register_static(&virtio_blk_info);
1064 type_init(virtio_register_types)