Merge tag 'edgar/xilinx-next-2022-09-21.for-upstream' of https://github.com/edgarigl...
[qemu.git] / hw / block / vhost-user-blk.c
1 /*
2 * vhost-user-blk host device
3 *
4 * Copyright(C) 2017 Intel Corporation.
5 *
6 * Authors:
7 * Changpeng Liu <changpeng.liu@intel.com>
8 *
9 * Largely based on the "vhost-user-scsi.c" and "vhost-scsi.c" implemented by:
10 * Felipe Franciosi <felipe@nutanix.com>
11 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
12 * Nicholas Bellinger <nab@risingtidesystems.com>
13 *
14 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
15 * See the COPYING.LIB file in the top-level directory.
16 *
17 */
18
19 #include "qemu/osdep.h"
20 #include "qapi/error.h"
21 #include "qemu/error-report.h"
22 #include "qemu/cutils.h"
23 #include "hw/qdev-core.h"
24 #include "hw/qdev-properties.h"
25 #include "hw/qdev-properties-system.h"
26 #include "hw/virtio/vhost.h"
27 #include "hw/virtio/vhost-user-blk.h"
28 #include "hw/virtio/virtio.h"
29 #include "hw/virtio/virtio-bus.h"
30 #include "hw/virtio/virtio-access.h"
31 #include "sysemu/sysemu.h"
32 #include "sysemu/runstate.h"
33
34 #define REALIZE_CONNECTION_RETRIES 3
35
36 static const int user_feature_bits[] = {
37 VIRTIO_BLK_F_SIZE_MAX,
38 VIRTIO_BLK_F_SEG_MAX,
39 VIRTIO_BLK_F_GEOMETRY,
40 VIRTIO_BLK_F_BLK_SIZE,
41 VIRTIO_BLK_F_TOPOLOGY,
42 VIRTIO_BLK_F_MQ,
43 VIRTIO_BLK_F_RO,
44 VIRTIO_BLK_F_FLUSH,
45 VIRTIO_BLK_F_CONFIG_WCE,
46 VIRTIO_BLK_F_DISCARD,
47 VIRTIO_BLK_F_WRITE_ZEROES,
48 VIRTIO_F_VERSION_1,
49 VIRTIO_RING_F_INDIRECT_DESC,
50 VIRTIO_RING_F_EVENT_IDX,
51 VIRTIO_F_NOTIFY_ON_EMPTY,
52 VIRTIO_F_RING_PACKED,
53 VIRTIO_F_IOMMU_PLATFORM,
54 VHOST_INVALID_FEATURE_BIT
55 };
56
57 static void vhost_user_blk_event(void *opaque, QEMUChrEvent event);
58
59 static void vhost_user_blk_update_config(VirtIODevice *vdev, uint8_t *config)
60 {
61 VHostUserBlk *s = VHOST_USER_BLK(vdev);
62
63 /* Our num_queues overrides the device backend */
64 virtio_stw_p(vdev, &s->blkcfg.num_queues, s->num_queues);
65
66 memcpy(config, &s->blkcfg, sizeof(struct virtio_blk_config));
67 }
68
69 static void vhost_user_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
70 {
71 VHostUserBlk *s = VHOST_USER_BLK(vdev);
72 struct virtio_blk_config *blkcfg = (struct virtio_blk_config *)config;
73 int ret;
74
75 if (blkcfg->wce == s->blkcfg.wce) {
76 return;
77 }
78
79 ret = vhost_dev_set_config(&s->dev, &blkcfg->wce,
80 offsetof(struct virtio_blk_config, wce),
81 sizeof(blkcfg->wce),
82 VHOST_SET_CONFIG_TYPE_MASTER);
83 if (ret) {
84 error_report("set device config space failed");
85 return;
86 }
87
88 s->blkcfg.wce = blkcfg->wce;
89 }
90
91 static int vhost_user_blk_handle_config_change(struct vhost_dev *dev)
92 {
93 int ret;
94 struct virtio_blk_config blkcfg;
95 VHostUserBlk *s = VHOST_USER_BLK(dev->vdev);
96 Error *local_err = NULL;
97
98 ret = vhost_dev_get_config(dev, (uint8_t *)&blkcfg,
99 sizeof(struct virtio_blk_config),
100 &local_err);
101 if (ret < 0) {
102 error_report_err(local_err);
103 return ret;
104 }
105
106 /* valid for resize only */
107 if (blkcfg.capacity != s->blkcfg.capacity) {
108 s->blkcfg.capacity = blkcfg.capacity;
109 memcpy(dev->vdev->config, &s->blkcfg, sizeof(struct virtio_blk_config));
110 virtio_notify_config(dev->vdev);
111 }
112
113 return 0;
114 }
115
116 const VhostDevConfigOps blk_ops = {
117 .vhost_dev_config_notifier = vhost_user_blk_handle_config_change,
118 };
119
120 static int vhost_user_blk_start(VirtIODevice *vdev, Error **errp)
121 {
122 VHostUserBlk *s = VHOST_USER_BLK(vdev);
123 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
124 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
125 int i, ret;
126
127 if (!k->set_guest_notifiers) {
128 error_setg(errp, "binding does not support guest notifiers");
129 return -ENOSYS;
130 }
131
132 ret = vhost_dev_enable_notifiers(&s->dev, vdev);
133 if (ret < 0) {
134 error_setg_errno(errp, -ret, "Error enabling host notifiers");
135 return ret;
136 }
137
138 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
139 if (ret < 0) {
140 error_setg_errno(errp, -ret, "Error binding guest notifier");
141 goto err_host_notifiers;
142 }
143
144 s->dev.acked_features = vdev->guest_features;
145
146 ret = vhost_dev_prepare_inflight(&s->dev, vdev);
147 if (ret < 0) {
148 error_setg_errno(errp, -ret, "Error setting inflight format");
149 goto err_guest_notifiers;
150 }
151
152 if (!s->inflight->addr) {
153 ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight);
154 if (ret < 0) {
155 error_setg_errno(errp, -ret, "Error getting inflight");
156 goto err_guest_notifiers;
157 }
158 }
159
160 ret = vhost_dev_set_inflight(&s->dev, s->inflight);
161 if (ret < 0) {
162 error_setg_errno(errp, -ret, "Error setting inflight");
163 goto err_guest_notifiers;
164 }
165
166 ret = vhost_dev_start(&s->dev, vdev);
167 if (ret < 0) {
168 error_setg_errno(errp, -ret, "Error starting vhost");
169 goto err_guest_notifiers;
170 }
171 s->started_vu = true;
172
173 /* guest_notifier_mask/pending not used yet, so just unmask
174 * everything here. virtio-pci will do the right thing by
175 * enabling/disabling irqfd.
176 */
177 for (i = 0; i < s->dev.nvqs; i++) {
178 vhost_virtqueue_mask(&s->dev, vdev, i, false);
179 }
180
181 return ret;
182
183 err_guest_notifiers:
184 k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
185 err_host_notifiers:
186 vhost_dev_disable_notifiers(&s->dev, vdev);
187 return ret;
188 }
189
190 static void vhost_user_blk_stop(VirtIODevice *vdev)
191 {
192 VHostUserBlk *s = VHOST_USER_BLK(vdev);
193 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
194 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
195 int ret;
196
197 if (!s->started_vu) {
198 return;
199 }
200 s->started_vu = false;
201
202 if (!k->set_guest_notifiers) {
203 return;
204 }
205
206 vhost_dev_stop(&s->dev, vdev);
207
208 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
209 if (ret < 0) {
210 error_report("vhost guest notifier cleanup failed: %d", ret);
211 return;
212 }
213
214 vhost_dev_disable_notifiers(&s->dev, vdev);
215 }
216
217 static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status)
218 {
219 VHostUserBlk *s = VHOST_USER_BLK(vdev);
220 bool should_start = virtio_device_started(vdev, status);
221 Error *local_err = NULL;
222 int ret;
223
224 if (!vdev->vm_running) {
225 should_start = false;
226 }
227
228 if (!s->connected) {
229 return;
230 }
231
232 if (s->dev.started == should_start) {
233 return;
234 }
235
236 if (should_start) {
237 ret = vhost_user_blk_start(vdev, &local_err);
238 if (ret < 0) {
239 error_reportf_err(local_err, "vhost-user-blk: vhost start failed: ");
240 qemu_chr_fe_disconnect(&s->chardev);
241 }
242 } else {
243 vhost_user_blk_stop(vdev);
244 }
245
246 }
247
248 static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
249 uint64_t features,
250 Error **errp)
251 {
252 VHostUserBlk *s = VHOST_USER_BLK(vdev);
253
254 /* Turn on pre-defined features */
255 virtio_add_feature(&features, VIRTIO_BLK_F_SIZE_MAX);
256 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
257 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
258 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
259 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
260 virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH);
261 virtio_add_feature(&features, VIRTIO_BLK_F_RO);
262 virtio_add_feature(&features, VIRTIO_BLK_F_DISCARD);
263 virtio_add_feature(&features, VIRTIO_BLK_F_WRITE_ZEROES);
264
265 if (s->config_wce) {
266 virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE);
267 }
268 if (s->num_queues > 1) {
269 virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
270 }
271
272 return vhost_get_features(&s->dev, user_feature_bits, features);
273 }
274
275 static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
276 {
277 VHostUserBlk *s = VHOST_USER_BLK(vdev);
278 Error *local_err = NULL;
279 int i, ret;
280
281 if (!vdev->start_on_kick) {
282 return;
283 }
284
285 if (!s->connected) {
286 return;
287 }
288
289 if (s->dev.started) {
290 return;
291 }
292
293 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
294 * vhost here instead of waiting for .set_status().
295 */
296 ret = vhost_user_blk_start(vdev, &local_err);
297 if (ret < 0) {
298 error_reportf_err(local_err, "vhost-user-blk: vhost start failed: ");
299 qemu_chr_fe_disconnect(&s->chardev);
300 return;
301 }
302
303 /* Kick right away to begin processing requests already in vring */
304 for (i = 0; i < s->dev.nvqs; i++) {
305 VirtQueue *kick_vq = virtio_get_queue(vdev, i);
306
307 if (!virtio_queue_get_desc_addr(vdev, i)) {
308 continue;
309 }
310 event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
311 }
312 }
313
314 static void vhost_user_blk_reset(VirtIODevice *vdev)
315 {
316 VHostUserBlk *s = VHOST_USER_BLK(vdev);
317
318 vhost_dev_free_inflight(s->inflight);
319 }
320
321 static int vhost_user_blk_connect(DeviceState *dev, Error **errp)
322 {
323 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
324 VHostUserBlk *s = VHOST_USER_BLK(vdev);
325 int ret = 0;
326
327 if (s->connected) {
328 return 0;
329 }
330 s->connected = true;
331
332 s->dev.num_queues = s->num_queues;
333 s->dev.nvqs = s->num_queues;
334 s->dev.vqs = s->vhost_vqs;
335 s->dev.vq_index = 0;
336 s->dev.backend_features = 0;
337
338 vhost_dev_set_config_notifier(&s->dev, &blk_ops);
339
340 ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0,
341 errp);
342 if (ret < 0) {
343 return ret;
344 }
345
346 /* restore vhost state */
347 if (virtio_device_started(vdev, vdev->status)) {
348 ret = vhost_user_blk_start(vdev, errp);
349 if (ret < 0) {
350 return ret;
351 }
352 }
353
354 return 0;
355 }
356
357 static void vhost_user_blk_disconnect(DeviceState *dev)
358 {
359 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
360 VHostUserBlk *s = VHOST_USER_BLK(vdev);
361
362 if (!s->connected) {
363 return;
364 }
365 s->connected = false;
366
367 vhost_user_blk_stop(vdev);
368
369 vhost_dev_cleanup(&s->dev);
370 }
371
372 static void vhost_user_blk_chr_closed_bh(void *opaque)
373 {
374 DeviceState *dev = opaque;
375 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
376 VHostUserBlk *s = VHOST_USER_BLK(vdev);
377
378 vhost_user_blk_disconnect(dev);
379 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event,
380 NULL, opaque, NULL, true);
381 }
382
383 static void vhost_user_blk_event(void *opaque, QEMUChrEvent event)
384 {
385 DeviceState *dev = opaque;
386 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
387 VHostUserBlk *s = VHOST_USER_BLK(vdev);
388 Error *local_err = NULL;
389
390 switch (event) {
391 case CHR_EVENT_OPENED:
392 if (vhost_user_blk_connect(dev, &local_err) < 0) {
393 error_report_err(local_err);
394 qemu_chr_fe_disconnect(&s->chardev);
395 return;
396 }
397 break;
398 case CHR_EVENT_CLOSED:
399 if (!runstate_check(RUN_STATE_SHUTDOWN)) {
400 /*
401 * A close event may happen during a read/write, but vhost
402 * code assumes the vhost_dev remains setup, so delay the
403 * stop & clear.
404 */
405 AioContext *ctx = qemu_get_current_aio_context();
406
407 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, NULL,
408 NULL, NULL, false);
409 aio_bh_schedule_oneshot(ctx, vhost_user_blk_chr_closed_bh, opaque);
410
411 /*
412 * Move vhost device to the stopped state. The vhost-user device
413 * will be clean up and disconnected in BH. This can be useful in
414 * the vhost migration code. If disconnect was caught there is an
415 * option for the general vhost code to get the dev state without
416 * knowing its type (in this case vhost-user).
417 */
418 s->dev.started = false;
419 }
420 break;
421 case CHR_EVENT_BREAK:
422 case CHR_EVENT_MUX_IN:
423 case CHR_EVENT_MUX_OUT:
424 /* Ignore */
425 break;
426 }
427 }
428
429 static int vhost_user_blk_realize_connect(VHostUserBlk *s, Error **errp)
430 {
431 DeviceState *dev = &s->parent_obj.parent_obj;
432 int ret;
433
434 s->connected = false;
435
436 ret = qemu_chr_fe_wait_connected(&s->chardev, errp);
437 if (ret < 0) {
438 return ret;
439 }
440
441 ret = vhost_user_blk_connect(dev, errp);
442 if (ret < 0) {
443 qemu_chr_fe_disconnect(&s->chardev);
444 return ret;
445 }
446 assert(s->connected);
447
448 ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg,
449 sizeof(struct virtio_blk_config), errp);
450 if (ret < 0) {
451 qemu_chr_fe_disconnect(&s->chardev);
452 vhost_dev_cleanup(&s->dev);
453 return ret;
454 }
455
456 return 0;
457 }
458
459 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
460 {
461 ERRP_GUARD();
462 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
463 VHostUserBlk *s = VHOST_USER_BLK(vdev);
464 int retries;
465 int i, ret;
466
467 if (!s->chardev.chr) {
468 error_setg(errp, "chardev is mandatory");
469 return;
470 }
471
472 if (s->num_queues == VHOST_USER_BLK_AUTO_NUM_QUEUES) {
473 s->num_queues = 1;
474 }
475 if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) {
476 error_setg(errp, "invalid number of IO queues");
477 return;
478 }
479
480 if (!s->queue_size) {
481 error_setg(errp, "queue size must be non-zero");
482 return;
483 }
484 if (s->queue_size > VIRTQUEUE_MAX_SIZE) {
485 error_setg(errp, "queue size must not exceed %d",
486 VIRTQUEUE_MAX_SIZE);
487 return;
488 }
489
490 if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) {
491 return;
492 }
493
494 virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
495 sizeof(struct virtio_blk_config));
496
497 s->virtqs = g_new(VirtQueue *, s->num_queues);
498 for (i = 0; i < s->num_queues; i++) {
499 s->virtqs[i] = virtio_add_queue(vdev, s->queue_size,
500 vhost_user_blk_handle_output);
501 }
502
503 s->inflight = g_new0(struct vhost_inflight, 1);
504 s->vhost_vqs = g_new0(struct vhost_virtqueue, s->num_queues);
505
506 retries = REALIZE_CONNECTION_RETRIES;
507 assert(!*errp);
508 do {
509 if (*errp) {
510 error_prepend(errp, "Reconnecting after error: ");
511 error_report_err(*errp);
512 *errp = NULL;
513 }
514 ret = vhost_user_blk_realize_connect(s, errp);
515 } while (ret < 0 && retries--);
516
517 if (ret < 0) {
518 goto virtio_err;
519 }
520
521 /* we're fully initialized, now we can operate, so add the handler */
522 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL,
523 vhost_user_blk_event, NULL, (void *)dev,
524 NULL, true);
525 return;
526
527 virtio_err:
528 g_free(s->vhost_vqs);
529 s->vhost_vqs = NULL;
530 g_free(s->inflight);
531 s->inflight = NULL;
532 for (i = 0; i < s->num_queues; i++) {
533 virtio_delete_queue(s->virtqs[i]);
534 }
535 g_free(s->virtqs);
536 virtio_cleanup(vdev);
537 vhost_user_cleanup(&s->vhost_user);
538 }
539
540 static void vhost_user_blk_device_unrealize(DeviceState *dev)
541 {
542 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
543 VHostUserBlk *s = VHOST_USER_BLK(dev);
544 int i;
545
546 virtio_set_status(vdev, 0);
547 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL,
548 NULL, NULL, NULL, false);
549 vhost_dev_cleanup(&s->dev);
550 vhost_dev_free_inflight(s->inflight);
551 g_free(s->vhost_vqs);
552 s->vhost_vqs = NULL;
553 g_free(s->inflight);
554 s->inflight = NULL;
555
556 for (i = 0; i < s->num_queues; i++) {
557 virtio_delete_queue(s->virtqs[i]);
558 }
559 g_free(s->virtqs);
560 virtio_cleanup(vdev);
561 vhost_user_cleanup(&s->vhost_user);
562 }
563
564 static void vhost_user_blk_instance_init(Object *obj)
565 {
566 VHostUserBlk *s = VHOST_USER_BLK(obj);
567
568 device_add_bootindex_property(obj, &s->bootindex, "bootindex",
569 "/disk@0,0", DEVICE(obj));
570 }
571
572 static const VMStateDescription vmstate_vhost_user_blk = {
573 .name = "vhost-user-blk",
574 .minimum_version_id = 1,
575 .version_id = 1,
576 .fields = (VMStateField[]) {
577 VMSTATE_VIRTIO_DEVICE,
578 VMSTATE_END_OF_LIST()
579 },
580 };
581
582 static Property vhost_user_blk_properties[] = {
583 DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev),
584 DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues,
585 VHOST_USER_BLK_AUTO_NUM_QUEUES),
586 DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128),
587 DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true),
588 DEFINE_PROP_END_OF_LIST(),
589 };
590
591 static void vhost_user_blk_class_init(ObjectClass *klass, void *data)
592 {
593 DeviceClass *dc = DEVICE_CLASS(klass);
594 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
595
596 device_class_set_props(dc, vhost_user_blk_properties);
597 dc->vmsd = &vmstate_vhost_user_blk;
598 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
599 vdc->realize = vhost_user_blk_device_realize;
600 vdc->unrealize = vhost_user_blk_device_unrealize;
601 vdc->get_config = vhost_user_blk_update_config;
602 vdc->set_config = vhost_user_blk_set_config;
603 vdc->get_features = vhost_user_blk_get_features;
604 vdc->set_status = vhost_user_blk_set_status;
605 vdc->reset = vhost_user_blk_reset;
606 }
607
608 static const TypeInfo vhost_user_blk_info = {
609 .name = TYPE_VHOST_USER_BLK,
610 .parent = TYPE_VIRTIO_DEVICE,
611 .instance_size = sizeof(VHostUserBlk),
612 .instance_init = vhost_user_blk_instance_init,
613 .class_init = vhost_user_blk_class_init,
614 };
615
616 static void virtio_register_types(void)
617 {
618 type_register_static(&vhost_user_blk_info);
619 }
620
621 type_init(virtio_register_types)