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 "qom/object.h"
24#include "hw/qdev-core.h"
25#include "hw/qdev-properties.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
34static const int user_feature_bits[] = {
35 VIRTIO_BLK_F_SIZE_MAX,
36 VIRTIO_BLK_F_SEG_MAX,
37 VIRTIO_BLK_F_GEOMETRY,
38 VIRTIO_BLK_F_BLK_SIZE,
39 VIRTIO_BLK_F_TOPOLOGY,
40 VIRTIO_BLK_F_MQ,
41 VIRTIO_BLK_F_RO,
42 VIRTIO_BLK_F_FLUSH,
43 VIRTIO_BLK_F_CONFIG_WCE,
44 VIRTIO_BLK_F_DISCARD,
45 VIRTIO_BLK_F_WRITE_ZEROES,
46 VIRTIO_F_VERSION_1,
47 VIRTIO_RING_F_INDIRECT_DESC,
48 VIRTIO_RING_F_EVENT_IDX,
49 VIRTIO_F_NOTIFY_ON_EMPTY,
50 VHOST_INVALID_FEATURE_BIT
51};
52
53static void vhost_user_blk_update_config(VirtIODevice *vdev, uint8_t *config)
54{
55 VHostUserBlk *s = VHOST_USER_BLK(vdev);
56
57 memcpy(config, &s->blkcfg, sizeof(struct virtio_blk_config));
58}
59
60static void vhost_user_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
61{
62 VHostUserBlk *s = VHOST_USER_BLK(vdev);
63 struct virtio_blk_config *blkcfg = (struct virtio_blk_config *)config;
64 int ret;
65
66 if (blkcfg->wce == s->blkcfg.wce) {
67 return;
68 }
69
70 ret = vhost_dev_set_config(&s->dev, &blkcfg->wce,
71 offsetof(struct virtio_blk_config, wce),
72 sizeof(blkcfg->wce),
73 VHOST_SET_CONFIG_TYPE_MASTER);
74 if (ret) {
75 error_report("set device config space failed");
76 return;
77 }
78
79 s->blkcfg.wce = blkcfg->wce;
80}
81
82static int vhost_user_blk_handle_config_change(struct vhost_dev *dev)
83{
84 int ret;
85 struct virtio_blk_config blkcfg;
86 VHostUserBlk *s = VHOST_USER_BLK(dev->vdev);
87
88 ret = vhost_dev_get_config(dev, (uint8_t *)&blkcfg,
89 sizeof(struct virtio_blk_config));
90 if (ret < 0) {
91 error_report("get config space failed");
92 return -1;
93 }
94
95 /* valid for resize only */
96 if (blkcfg.capacity != s->blkcfg.capacity) {
97 s->blkcfg.capacity = blkcfg.capacity;
98 memcpy(dev->vdev->config, &s->blkcfg, sizeof(struct virtio_blk_config));
99 virtio_notify_config(dev->vdev);
100 }
101
102 return 0;
103}
104
105const VhostDevConfigOps blk_ops = {
106 .vhost_dev_config_notifier = vhost_user_blk_handle_config_change,
107};
108
109static int vhost_user_blk_start(VirtIODevice *vdev)
110{
111 VHostUserBlk *s = VHOST_USER_BLK(vdev);
112 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
113 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
114 int i, ret;
115
116 if (!k->set_guest_notifiers) {
117 error_report("binding does not support guest notifiers");
118 return -ENOSYS;
119 }
120
121 ret = vhost_dev_enable_notifiers(&s->dev, vdev);
122 if (ret < 0) {
123 error_report("Error enabling host notifiers: %d", -ret);
124 return ret;
125 }
126
127 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
128 if (ret < 0) {
129 error_report("Error binding guest notifier: %d", -ret);
130 goto err_host_notifiers;
131 }
132
133 s->dev.acked_features = vdev->guest_features;
134
135 if (!s->inflight->addr) {
136 ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight);
137 if (ret < 0) {
138 error_report("Error get inflight: %d", -ret);
139 goto err_guest_notifiers;
140 }
141 }
142
143 ret = vhost_dev_set_inflight(&s->dev, s->inflight);
144 if (ret < 0) {
145 error_report("Error set inflight: %d", -ret);
146 goto err_guest_notifiers;
147 }
148
149 ret = vhost_dev_start(&s->dev, vdev);
150 if (ret < 0) {
151 error_report("Error starting vhost: %d", -ret);
152 goto err_guest_notifiers;
153 }
154
155 /* guest_notifier_mask/pending not used yet, so just unmask
156 * everything here. virtio-pci will do the right thing by
157 * enabling/disabling irqfd.
158 */
159 for (i = 0; i < s->dev.nvqs; i++) {
160 vhost_virtqueue_mask(&s->dev, vdev, i, false);
161 }
162
163 return ret;
164
165err_guest_notifiers:
166 k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
167err_host_notifiers:
168 vhost_dev_disable_notifiers(&s->dev, vdev);
169 return ret;
170}
171
172static void vhost_user_blk_stop(VirtIODevice *vdev)
173{
174 VHostUserBlk *s = VHOST_USER_BLK(vdev);
175 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
176 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
177 int ret;
178
179 if (!k->set_guest_notifiers) {
180 return;
181 }
182
183 vhost_dev_stop(&s->dev, vdev);
184
185 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
186 if (ret < 0) {
187 error_report("vhost guest notifier cleanup failed: %d", ret);
188 return;
189 }
190
191 vhost_dev_disable_notifiers(&s->dev, vdev);
192}
193
194static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status)
195{
196 VHostUserBlk *s = VHOST_USER_BLK(vdev);
197 bool should_start = virtio_device_started(vdev, status);
198 int ret;
199
200 if (!vdev->vm_running) {
201 should_start = false;
202 }
203
204 if (!s->connected) {
205 return;
206 }
207
208 if (s->dev.started == should_start) {
209 return;
210 }
211
212 if (should_start) {
213 ret = vhost_user_blk_start(vdev);
214 if (ret < 0) {
215 error_report("vhost-user-blk: vhost start failed: %s",
216 strerror(-ret));
217 qemu_chr_fe_disconnect(&s->chardev);
218 }
219 } else {
220 vhost_user_blk_stop(vdev);
221 }
222
223}
224
225static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
226 uint64_t features,
227 Error **errp)
228{
229 VHostUserBlk *s = VHOST_USER_BLK(vdev);
230
231 /* Turn on pre-defined features */
232 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
233 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
234 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
235 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
236 virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH);
237 virtio_add_feature(&features, VIRTIO_BLK_F_RO);
238 virtio_add_feature(&features, VIRTIO_BLK_F_DISCARD);
239 virtio_add_feature(&features, VIRTIO_BLK_F_WRITE_ZEROES);
240
241 if (s->config_wce) {
242 virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE);
243 }
244 if (s->num_queues > 1) {
245 virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
246 }
247
248 return vhost_get_features(&s->dev, user_feature_bits, features);
249}
250
251static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
252{
253 VHostUserBlk *s = VHOST_USER_BLK(vdev);
254 int i, ret;
255
256 if (!vdev->start_on_kick) {
257 return;
258 }
259
260 if (!s->connected) {
261 return;
262 }
263
264 if (s->dev.started) {
265 return;
266 }
267
268 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
269 * vhost here instead of waiting for .set_status().
270 */
271 ret = vhost_user_blk_start(vdev);
272 if (ret < 0) {
273 error_report("vhost-user-blk: vhost start failed: %s",
274 strerror(-ret));
275 qemu_chr_fe_disconnect(&s->chardev);
276 return;
277 }
278
279 /* Kick right away to begin processing requests already in vring */
280 for (i = 0; i < s->dev.nvqs; i++) {
281 VirtQueue *kick_vq = virtio_get_queue(vdev, i);
282
283 if (!virtio_queue_get_desc_addr(vdev, i)) {
284 continue;
285 }
286 event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
287 }
288}
289
290static void vhost_user_blk_reset(VirtIODevice *vdev)
291{
292 VHostUserBlk *s = VHOST_USER_BLK(vdev);
293
294 vhost_dev_free_inflight(s->inflight);
295}
296
297static int vhost_user_blk_connect(DeviceState *dev)
298{
299 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
300 VHostUserBlk *s = VHOST_USER_BLK(vdev);
301 int ret = 0;
302
303 if (s->connected) {
304 return 0;
305 }
306 s->connected = true;
307
308 s->dev.nvqs = s->num_queues;
309 s->dev.vqs = s->vqs;
310 s->dev.vq_index = 0;
311 s->dev.backend_features = 0;
312
313 vhost_dev_set_config_notifier(&s->dev, &blk_ops);
314
315 ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0);
316 if (ret < 0) {
317 error_report("vhost-user-blk: vhost initialization failed: %s",
318 strerror(-ret));
319 return ret;
320 }
321
322 /* restore vhost state */
323 if (virtio_device_started(vdev, vdev->status)) {
324 ret = vhost_user_blk_start(vdev);
325 if (ret < 0) {
326 error_report("vhost-user-blk: vhost start failed: %s",
327 strerror(-ret));
328 return ret;
329 }
330 }
331
332 return 0;
333}
334
335static void vhost_user_blk_disconnect(DeviceState *dev)
336{
337 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
338 VHostUserBlk *s = VHOST_USER_BLK(vdev);
339
340 if (!s->connected) {
341 return;
342 }
343 s->connected = false;
344
345 if (s->dev.started) {
346 vhost_user_blk_stop(vdev);
347 }
348
349 vhost_dev_cleanup(&s->dev);
350}
351
352static gboolean vhost_user_blk_watch(GIOChannel *chan, GIOCondition cond,
353 void *opaque)
354{
355 DeviceState *dev = opaque;
356 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
357 VHostUserBlk *s = VHOST_USER_BLK(vdev);
358
359 qemu_chr_fe_disconnect(&s->chardev);
360
361 return true;
362}
363
364static void vhost_user_blk_event(void *opaque, int event)
365{
366 DeviceState *dev = opaque;
367 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
368 VHostUserBlk *s = VHOST_USER_BLK(vdev);
369
370 switch (event) {
371 case CHR_EVENT_OPENED:
372 if (vhost_user_blk_connect(dev) < 0) {
373 qemu_chr_fe_disconnect(&s->chardev);
374 return;
375 }
376 s->watch = qemu_chr_fe_add_watch(&s->chardev, G_IO_HUP,
377 vhost_user_blk_watch, dev);
378 break;
379 case CHR_EVENT_CLOSED:
380 vhost_user_blk_disconnect(dev);
381 if (s->watch) {
382 g_source_remove(s->watch);
383 s->watch = 0;
384 }
385 break;
386 }
387}
388
389static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
390{
391 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
392 VHostUserBlk *s = VHOST_USER_BLK(vdev);
393 Error *err = NULL;
394 int i, ret;
395
396 if (!s->chardev.chr) {
397 error_setg(errp, "vhost-user-blk: chardev is mandatory");
398 return;
399 }
400
401 if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) {
402 error_setg(errp, "vhost-user-blk: invalid number of IO queues");
403 return;
404 }
405
406 if (!s->queue_size) {
407 error_setg(errp, "vhost-user-blk: queue size must be non-zero");
408 return;
409 }
410
411 if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) {
412 return;
413 }
414
415 virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
416 sizeof(struct virtio_blk_config));
417
418 for (i = 0; i < s->num_queues; i++) {
419 virtio_add_queue(vdev, s->queue_size,
420 vhost_user_blk_handle_output);
421 }
422
423 s->inflight = g_new0(struct vhost_inflight, 1);
424 s->vqs = g_new(struct vhost_virtqueue, s->num_queues);
425 s->watch = 0;
426 s->connected = false;
427
428 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event,
429 NULL, (void *)dev, NULL, true);
430
431reconnect:
432 if (qemu_chr_fe_wait_connected(&s->chardev, &err) < 0) {
433 error_report_err(err);
434 goto virtio_err;
435 }
436
437 /* check whether vhost_user_blk_connect() failed or not */
438 if (!s->connected) {
439 goto reconnect;
440 }
441
442 ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg,
443 sizeof(struct virtio_blk_config));
444 if (ret < 0) {
445 error_report("vhost-user-blk: get block config failed");
446 goto reconnect;
447 }
448
449 if (s->blkcfg.num_queues != s->num_queues) {
450 s->blkcfg.num_queues = s->num_queues;
451 }
452
453 return;
454
455virtio_err:
456 g_free(s->vqs);
457 g_free(s->inflight);
458 virtio_cleanup(vdev);
459 vhost_user_cleanup(&s->vhost_user);
460}
461
462static void vhost_user_blk_device_unrealize(DeviceState *dev, Error **errp)
463{
464 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
465 VHostUserBlk *s = VHOST_USER_BLK(dev);
466
467 virtio_set_status(vdev, 0);
468 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL,
469 NULL, NULL, NULL, false);
470 vhost_dev_cleanup(&s->dev);
471 vhost_dev_free_inflight(s->inflight);
472 g_free(s->vqs);
473 g_free(s->inflight);
474 virtio_cleanup(vdev);
475 vhost_user_cleanup(&s->vhost_user);
476}
477
478static void vhost_user_blk_instance_init(Object *obj)
479{
480 VHostUserBlk *s = VHOST_USER_BLK(obj);
481
482 device_add_bootindex_property(obj, &s->bootindex, "bootindex",
483 "/disk@0,0", DEVICE(obj), NULL);
484}
485
486static const VMStateDescription vmstate_vhost_user_blk = {
487 .name = "vhost-user-blk",
488 .minimum_version_id = 1,
489 .version_id = 1,
490 .fields = (VMStateField[]) {
491 VMSTATE_VIRTIO_DEVICE,
492 VMSTATE_END_OF_LIST()
493 },
494};
495
496static Property vhost_user_blk_properties[] = {
497 DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev),
498 DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 1),
499 DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128),
500 DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true),
501 DEFINE_PROP_END_OF_LIST(),
502};
503
504static void vhost_user_blk_class_init(ObjectClass *klass, void *data)
505{
506 DeviceClass *dc = DEVICE_CLASS(klass);
507 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
508
509 dc->props = vhost_user_blk_properties;
510 dc->vmsd = &vmstate_vhost_user_blk;
511 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
512 vdc->realize = vhost_user_blk_device_realize;
513 vdc->unrealize = vhost_user_blk_device_unrealize;
514 vdc->get_config = vhost_user_blk_update_config;
515 vdc->set_config = vhost_user_blk_set_config;
516 vdc->get_features = vhost_user_blk_get_features;
517 vdc->set_status = vhost_user_blk_set_status;
518 vdc->reset = vhost_user_blk_reset;
519}
520
521static const TypeInfo vhost_user_blk_info = {
522 .name = TYPE_VHOST_USER_BLK,
523 .parent = TYPE_VIRTIO_DEVICE,
524 .instance_size = sizeof(VHostUserBlk),
525 .instance_init = vhost_user_blk_instance_init,
526 .class_init = vhost_user_blk_class_init,
527};
528
529static void virtio_register_types(void)
530{
531 type_register_static(&vhost_user_blk_info);
532}
533
534type_init(virtio_register_types)
535