xref: /openbmc/linux/drivers/vdpa/vdpa.c (revision 35267cea)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * vDPA bus.
4  *
5  * Copyright (c) 2020, Red Hat. All rights reserved.
6  *     Author: Jason Wang <jasowang@redhat.com>
7  *
8  */
9 
10 #include <linux/module.h>
11 #include <linux/idr.h>
12 #include <linux/slab.h>
13 #include <linux/vdpa.h>
14 #include <uapi/linux/vdpa.h>
15 #include <net/genetlink.h>
16 #include <linux/mod_devicetable.h>
17 
18 static LIST_HEAD(mdev_head);
19 /* A global mutex that protects vdpa management device and device level operations. */
20 static DEFINE_MUTEX(vdpa_dev_mutex);
21 static DEFINE_IDA(vdpa_index_ida);
22 
23 static struct genl_family vdpa_nl_family;
24 
25 static int vdpa_dev_probe(struct device *d)
26 {
27 	struct vdpa_device *vdev = dev_to_vdpa(d);
28 	struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver);
29 	int ret = 0;
30 
31 	if (drv && drv->probe)
32 		ret = drv->probe(vdev);
33 
34 	return ret;
35 }
36 
37 static int vdpa_dev_remove(struct device *d)
38 {
39 	struct vdpa_device *vdev = dev_to_vdpa(d);
40 	struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver);
41 
42 	if (drv && drv->remove)
43 		drv->remove(vdev);
44 
45 	return 0;
46 }
47 
48 static struct bus_type vdpa_bus = {
49 	.name  = "vdpa",
50 	.probe = vdpa_dev_probe,
51 	.remove = vdpa_dev_remove,
52 };
53 
54 static void vdpa_release_dev(struct device *d)
55 {
56 	struct vdpa_device *vdev = dev_to_vdpa(d);
57 	const struct vdpa_config_ops *ops = vdev->config;
58 
59 	if (ops->free)
60 		ops->free(vdev);
61 
62 	ida_simple_remove(&vdpa_index_ida, vdev->index);
63 	kfree(vdev);
64 }
65 
66 /**
67  * __vdpa_alloc_device - allocate and initilaize a vDPA device
68  * This allows driver to some prepartion after device is
69  * initialized but before registered.
70  * @parent: the parent device
71  * @config: the bus operations that is supported by this device
72  * @size: size of the parent structure that contains private data
73  * @name: name of the vdpa device; optional.
74  *
75  * Driver should use vdpa_alloc_device() wrapper macro instead of
76  * using this directly.
77  *
78  * Return: Returns an error when parent/config/dma_dev is not set or fail to get
79  *	   ida.
80  */
81 struct vdpa_device *__vdpa_alloc_device(struct device *parent,
82 					const struct vdpa_config_ops *config,
83 					size_t size, const char *name)
84 {
85 	struct vdpa_device *vdev;
86 	int err = -EINVAL;
87 
88 	if (!config)
89 		goto err;
90 
91 	if (!!config->dma_map != !!config->dma_unmap)
92 		goto err;
93 
94 	err = -ENOMEM;
95 	vdev = kzalloc(size, GFP_KERNEL);
96 	if (!vdev)
97 		goto err;
98 
99 	err = ida_alloc(&vdpa_index_ida, GFP_KERNEL);
100 	if (err < 0)
101 		goto err_ida;
102 
103 	vdev->dev.bus = &vdpa_bus;
104 	vdev->dev.parent = parent;
105 	vdev->dev.release = vdpa_release_dev;
106 	vdev->index = err;
107 	vdev->config = config;
108 	vdev->features_valid = false;
109 
110 	if (name)
111 		err = dev_set_name(&vdev->dev, "%s", name);
112 	else
113 		err = dev_set_name(&vdev->dev, "vdpa%u", vdev->index);
114 	if (err)
115 		goto err_name;
116 
117 	device_initialize(&vdev->dev);
118 
119 	return vdev;
120 
121 err_name:
122 	ida_simple_remove(&vdpa_index_ida, vdev->index);
123 err_ida:
124 	kfree(vdev);
125 err:
126 	return ERR_PTR(err);
127 }
128 EXPORT_SYMBOL_GPL(__vdpa_alloc_device);
129 
130 static int vdpa_name_match(struct device *dev, const void *data)
131 {
132 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
133 
134 	return (strcmp(dev_name(&vdev->dev), data) == 0);
135 }
136 
137 static int __vdpa_register_device(struct vdpa_device *vdev, int nvqs)
138 {
139 	struct device *dev;
140 
141 	vdev->nvqs = nvqs;
142 
143 	lockdep_assert_held(&vdpa_dev_mutex);
144 	dev = bus_find_device(&vdpa_bus, NULL, dev_name(&vdev->dev), vdpa_name_match);
145 	if (dev) {
146 		put_device(dev);
147 		return -EEXIST;
148 	}
149 	return device_add(&vdev->dev);
150 }
151 
152 /**
153  * _vdpa_register_device - register a vDPA device with vdpa lock held
154  * Caller must have a succeed call of vdpa_alloc_device() before.
155  * Caller must invoke this routine in the management device dev_add()
156  * callback after setting up valid mgmtdev for this vdpa device.
157  * @vdev: the vdpa device to be registered to vDPA bus
158  * @nvqs: number of virtqueues supported by this device
159  *
160  * Return: Returns an error when fail to add device to vDPA bus
161  */
162 int _vdpa_register_device(struct vdpa_device *vdev, int nvqs)
163 {
164 	if (!vdev->mdev)
165 		return -EINVAL;
166 
167 	return __vdpa_register_device(vdev, nvqs);
168 }
169 EXPORT_SYMBOL_GPL(_vdpa_register_device);
170 
171 /**
172  * vdpa_register_device - register a vDPA device
173  * Callers must have a succeed call of vdpa_alloc_device() before.
174  * @vdev: the vdpa device to be registered to vDPA bus
175  * @nvqs: number of virtqueues supported by this device
176  *
177  * Return: Returns an error when fail to add to vDPA bus
178  */
179 int vdpa_register_device(struct vdpa_device *vdev, int nvqs)
180 {
181 	int err;
182 
183 	mutex_lock(&vdpa_dev_mutex);
184 	err = __vdpa_register_device(vdev, nvqs);
185 	mutex_unlock(&vdpa_dev_mutex);
186 	return err;
187 }
188 EXPORT_SYMBOL_GPL(vdpa_register_device);
189 
190 /**
191  * _vdpa_unregister_device - unregister a vDPA device
192  * Caller must invoke this routine as part of management device dev_del()
193  * callback.
194  * @vdev: the vdpa device to be unregisted from vDPA bus
195  */
196 void _vdpa_unregister_device(struct vdpa_device *vdev)
197 {
198 	lockdep_assert_held(&vdpa_dev_mutex);
199 	WARN_ON(!vdev->mdev);
200 	device_unregister(&vdev->dev);
201 }
202 EXPORT_SYMBOL_GPL(_vdpa_unregister_device);
203 
204 /**
205  * vdpa_unregister_device - unregister a vDPA device
206  * @vdev: the vdpa device to be unregisted from vDPA bus
207  */
208 void vdpa_unregister_device(struct vdpa_device *vdev)
209 {
210 	mutex_lock(&vdpa_dev_mutex);
211 	device_unregister(&vdev->dev);
212 	mutex_unlock(&vdpa_dev_mutex);
213 }
214 EXPORT_SYMBOL_GPL(vdpa_unregister_device);
215 
216 /**
217  * __vdpa_register_driver - register a vDPA device driver
218  * @drv: the vdpa device driver to be registered
219  * @owner: module owner of the driver
220  *
221  * Return: Returns an err when fail to do the registration
222  */
223 int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner)
224 {
225 	drv->driver.bus = &vdpa_bus;
226 	drv->driver.owner = owner;
227 
228 	return driver_register(&drv->driver);
229 }
230 EXPORT_SYMBOL_GPL(__vdpa_register_driver);
231 
232 /**
233  * vdpa_unregister_driver - unregister a vDPA device driver
234  * @drv: the vdpa device driver to be unregistered
235  */
236 void vdpa_unregister_driver(struct vdpa_driver *drv)
237 {
238 	driver_unregister(&drv->driver);
239 }
240 EXPORT_SYMBOL_GPL(vdpa_unregister_driver);
241 
242 /**
243  * vdpa_mgmtdev_register - register a vdpa management device
244  *
245  * @mdev: Pointer to vdpa management device
246  * vdpa_mgmtdev_register() register a vdpa management device which supports
247  * vdpa device management.
248  * Return: Returns 0 on success or failure when required callback ops are not
249  *         initialized.
250  */
251 int vdpa_mgmtdev_register(struct vdpa_mgmt_dev *mdev)
252 {
253 	if (!mdev->device || !mdev->ops || !mdev->ops->dev_add || !mdev->ops->dev_del)
254 		return -EINVAL;
255 
256 	INIT_LIST_HEAD(&mdev->list);
257 	mutex_lock(&vdpa_dev_mutex);
258 	list_add_tail(&mdev->list, &mdev_head);
259 	mutex_unlock(&vdpa_dev_mutex);
260 	return 0;
261 }
262 EXPORT_SYMBOL_GPL(vdpa_mgmtdev_register);
263 
264 static int vdpa_match_remove(struct device *dev, void *data)
265 {
266 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
267 	struct vdpa_mgmt_dev *mdev = vdev->mdev;
268 
269 	if (mdev == data)
270 		mdev->ops->dev_del(mdev, vdev);
271 	return 0;
272 }
273 
274 void vdpa_mgmtdev_unregister(struct vdpa_mgmt_dev *mdev)
275 {
276 	mutex_lock(&vdpa_dev_mutex);
277 
278 	list_del(&mdev->list);
279 
280 	/* Filter out all the entries belong to this management device and delete it. */
281 	bus_for_each_dev(&vdpa_bus, NULL, mdev, vdpa_match_remove);
282 
283 	mutex_unlock(&vdpa_dev_mutex);
284 }
285 EXPORT_SYMBOL_GPL(vdpa_mgmtdev_unregister);
286 
287 static bool mgmtdev_handle_match(const struct vdpa_mgmt_dev *mdev,
288 				 const char *busname, const char *devname)
289 {
290 	/* Bus name is optional for simulated management device, so ignore the
291 	 * device with bus if bus attribute is provided.
292 	 */
293 	if ((busname && !mdev->device->bus) || (!busname && mdev->device->bus))
294 		return false;
295 
296 	if (!busname && strcmp(dev_name(mdev->device), devname) == 0)
297 		return true;
298 
299 	if (busname && (strcmp(mdev->device->bus->name, busname) == 0) &&
300 	    (strcmp(dev_name(mdev->device), devname) == 0))
301 		return true;
302 
303 	return false;
304 }
305 
306 static struct vdpa_mgmt_dev *vdpa_mgmtdev_get_from_attr(struct nlattr **attrs)
307 {
308 	struct vdpa_mgmt_dev *mdev;
309 	const char *busname = NULL;
310 	const char *devname;
311 
312 	if (!attrs[VDPA_ATTR_MGMTDEV_DEV_NAME])
313 		return ERR_PTR(-EINVAL);
314 	devname = nla_data(attrs[VDPA_ATTR_MGMTDEV_DEV_NAME]);
315 	if (attrs[VDPA_ATTR_MGMTDEV_BUS_NAME])
316 		busname = nla_data(attrs[VDPA_ATTR_MGMTDEV_BUS_NAME]);
317 
318 	list_for_each_entry(mdev, &mdev_head, list) {
319 		if (mgmtdev_handle_match(mdev, busname, devname))
320 			return mdev;
321 	}
322 	return ERR_PTR(-ENODEV);
323 }
324 
325 static int vdpa_nl_mgmtdev_handle_fill(struct sk_buff *msg, const struct vdpa_mgmt_dev *mdev)
326 {
327 	if (mdev->device->bus &&
328 	    nla_put_string(msg, VDPA_ATTR_MGMTDEV_BUS_NAME, mdev->device->bus->name))
329 		return -EMSGSIZE;
330 	if (nla_put_string(msg, VDPA_ATTR_MGMTDEV_DEV_NAME, dev_name(mdev->device)))
331 		return -EMSGSIZE;
332 	return 0;
333 }
334 
335 static int vdpa_mgmtdev_fill(const struct vdpa_mgmt_dev *mdev, struct sk_buff *msg,
336 			     u32 portid, u32 seq, int flags)
337 {
338 	u64 supported_classes = 0;
339 	void *hdr;
340 	int i = 0;
341 	int err;
342 
343 	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, VDPA_CMD_MGMTDEV_NEW);
344 	if (!hdr)
345 		return -EMSGSIZE;
346 	err = vdpa_nl_mgmtdev_handle_fill(msg, mdev);
347 	if (err)
348 		goto msg_err;
349 
350 	while (mdev->id_table[i].device) {
351 		supported_classes |= BIT(mdev->id_table[i].device);
352 		i++;
353 	}
354 
355 	if (nla_put_u64_64bit(msg, VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES,
356 			      supported_classes, VDPA_ATTR_UNSPEC)) {
357 		err = -EMSGSIZE;
358 		goto msg_err;
359 	}
360 
361 	genlmsg_end(msg, hdr);
362 	return 0;
363 
364 msg_err:
365 	genlmsg_cancel(msg, hdr);
366 	return err;
367 }
368 
369 static int vdpa_nl_cmd_mgmtdev_get_doit(struct sk_buff *skb, struct genl_info *info)
370 {
371 	struct vdpa_mgmt_dev *mdev;
372 	struct sk_buff *msg;
373 	int err;
374 
375 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
376 	if (!msg)
377 		return -ENOMEM;
378 
379 	mutex_lock(&vdpa_dev_mutex);
380 	mdev = vdpa_mgmtdev_get_from_attr(info->attrs);
381 	if (IS_ERR(mdev)) {
382 		mutex_unlock(&vdpa_dev_mutex);
383 		NL_SET_ERR_MSG_MOD(info->extack, "Fail to find the specified mgmt device");
384 		err = PTR_ERR(mdev);
385 		goto out;
386 	}
387 
388 	err = vdpa_mgmtdev_fill(mdev, msg, info->snd_portid, info->snd_seq, 0);
389 	mutex_unlock(&vdpa_dev_mutex);
390 	if (err)
391 		goto out;
392 	err = genlmsg_reply(msg, info);
393 	return err;
394 
395 out:
396 	nlmsg_free(msg);
397 	return err;
398 }
399 
400 static int
401 vdpa_nl_cmd_mgmtdev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
402 {
403 	struct vdpa_mgmt_dev *mdev;
404 	int start = cb->args[0];
405 	int idx = 0;
406 	int err;
407 
408 	mutex_lock(&vdpa_dev_mutex);
409 	list_for_each_entry(mdev, &mdev_head, list) {
410 		if (idx < start) {
411 			idx++;
412 			continue;
413 		}
414 		err = vdpa_mgmtdev_fill(mdev, msg, NETLINK_CB(cb->skb).portid,
415 					cb->nlh->nlmsg_seq, NLM_F_MULTI);
416 		if (err)
417 			goto out;
418 		idx++;
419 	}
420 out:
421 	mutex_unlock(&vdpa_dev_mutex);
422 	cb->args[0] = idx;
423 	return msg->len;
424 }
425 
426 static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *info)
427 {
428 	struct vdpa_mgmt_dev *mdev;
429 	const char *name;
430 	int err = 0;
431 
432 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
433 		return -EINVAL;
434 
435 	name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
436 
437 	mutex_lock(&vdpa_dev_mutex);
438 	mdev = vdpa_mgmtdev_get_from_attr(info->attrs);
439 	if (IS_ERR(mdev)) {
440 		NL_SET_ERR_MSG_MOD(info->extack, "Fail to find the specified management device");
441 		err = PTR_ERR(mdev);
442 		goto err;
443 	}
444 
445 	err = mdev->ops->dev_add(mdev, name);
446 err:
447 	mutex_unlock(&vdpa_dev_mutex);
448 	return err;
449 }
450 
451 static int vdpa_nl_cmd_dev_del_set_doit(struct sk_buff *skb, struct genl_info *info)
452 {
453 	struct vdpa_mgmt_dev *mdev;
454 	struct vdpa_device *vdev;
455 	struct device *dev;
456 	const char *name;
457 	int err = 0;
458 
459 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
460 		return -EINVAL;
461 	name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
462 
463 	mutex_lock(&vdpa_dev_mutex);
464 	dev = bus_find_device(&vdpa_bus, NULL, name, vdpa_name_match);
465 	if (!dev) {
466 		NL_SET_ERR_MSG_MOD(info->extack, "device not found");
467 		err = -ENODEV;
468 		goto dev_err;
469 	}
470 	vdev = container_of(dev, struct vdpa_device, dev);
471 	if (!vdev->mdev) {
472 		NL_SET_ERR_MSG_MOD(info->extack, "Only user created device can be deleted by user");
473 		err = -EINVAL;
474 		goto mdev_err;
475 	}
476 	mdev = vdev->mdev;
477 	mdev->ops->dev_del(mdev, vdev);
478 mdev_err:
479 	put_device(dev);
480 dev_err:
481 	mutex_unlock(&vdpa_dev_mutex);
482 	return err;
483 }
484 
485 static int
486 vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
487 	      int flags, struct netlink_ext_ack *extack)
488 {
489 	u16 max_vq_size;
490 	u32 device_id;
491 	u32 vendor_id;
492 	void *hdr;
493 	int err;
494 
495 	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, VDPA_CMD_DEV_NEW);
496 	if (!hdr)
497 		return -EMSGSIZE;
498 
499 	err = vdpa_nl_mgmtdev_handle_fill(msg, vdev->mdev);
500 	if (err)
501 		goto msg_err;
502 
503 	device_id = vdev->config->get_device_id(vdev);
504 	vendor_id = vdev->config->get_vendor_id(vdev);
505 	max_vq_size = vdev->config->get_vq_num_max(vdev);
506 
507 	err = -EMSGSIZE;
508 	if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev)))
509 		goto msg_err;
510 	if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id))
511 		goto msg_err;
512 	if (nla_put_u32(msg, VDPA_ATTR_DEV_VENDOR_ID, vendor_id))
513 		goto msg_err;
514 	if (nla_put_u32(msg, VDPA_ATTR_DEV_MAX_VQS, vdev->nvqs))
515 		goto msg_err;
516 	if (nla_put_u16(msg, VDPA_ATTR_DEV_MAX_VQ_SIZE, max_vq_size))
517 		goto msg_err;
518 
519 	genlmsg_end(msg, hdr);
520 	return 0;
521 
522 msg_err:
523 	genlmsg_cancel(msg, hdr);
524 	return err;
525 }
526 
527 static int vdpa_nl_cmd_dev_get_doit(struct sk_buff *skb, struct genl_info *info)
528 {
529 	struct vdpa_device *vdev;
530 	struct sk_buff *msg;
531 	const char *devname;
532 	struct device *dev;
533 	int err;
534 
535 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
536 		return -EINVAL;
537 	devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
538 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
539 	if (!msg)
540 		return -ENOMEM;
541 
542 	mutex_lock(&vdpa_dev_mutex);
543 	dev = bus_find_device(&vdpa_bus, NULL, devname, vdpa_name_match);
544 	if (!dev) {
545 		NL_SET_ERR_MSG_MOD(info->extack, "device not found");
546 		err = -ENODEV;
547 		goto err;
548 	}
549 	vdev = container_of(dev, struct vdpa_device, dev);
550 	if (!vdev->mdev) {
551 		err = -EINVAL;
552 		goto mdev_err;
553 	}
554 	err = vdpa_dev_fill(vdev, msg, info->snd_portid, info->snd_seq, 0, info->extack);
555 	if (!err)
556 		err = genlmsg_reply(msg, info);
557 mdev_err:
558 	put_device(dev);
559 err:
560 	mutex_unlock(&vdpa_dev_mutex);
561 	if (err)
562 		nlmsg_free(msg);
563 	return err;
564 }
565 
566 struct vdpa_dev_dump_info {
567 	struct sk_buff *msg;
568 	struct netlink_callback *cb;
569 	int start_idx;
570 	int idx;
571 };
572 
573 static int vdpa_dev_dump(struct device *dev, void *data)
574 {
575 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
576 	struct vdpa_dev_dump_info *info = data;
577 	int err;
578 
579 	if (!vdev->mdev)
580 		return 0;
581 	if (info->idx < info->start_idx) {
582 		info->idx++;
583 		return 0;
584 	}
585 	err = vdpa_dev_fill(vdev, info->msg, NETLINK_CB(info->cb->skb).portid,
586 			    info->cb->nlh->nlmsg_seq, NLM_F_MULTI, info->cb->extack);
587 	if (err)
588 		return err;
589 
590 	info->idx++;
591 	return 0;
592 }
593 
594 static int vdpa_nl_cmd_dev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
595 {
596 	struct vdpa_dev_dump_info info;
597 
598 	info.msg = msg;
599 	info.cb = cb;
600 	info.start_idx = cb->args[0];
601 	info.idx = 0;
602 
603 	mutex_lock(&vdpa_dev_mutex);
604 	bus_for_each_dev(&vdpa_bus, NULL, &info, vdpa_dev_dump);
605 	mutex_unlock(&vdpa_dev_mutex);
606 	cb->args[0] = info.idx;
607 	return msg->len;
608 }
609 
610 static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = {
611 	[VDPA_ATTR_MGMTDEV_BUS_NAME] = { .type = NLA_NUL_STRING },
612 	[VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING },
613 	[VDPA_ATTR_DEV_NAME] = { .type = NLA_STRING },
614 };
615 
616 static const struct genl_ops vdpa_nl_ops[] = {
617 	{
618 		.cmd = VDPA_CMD_MGMTDEV_GET,
619 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
620 		.doit = vdpa_nl_cmd_mgmtdev_get_doit,
621 		.dumpit = vdpa_nl_cmd_mgmtdev_get_dumpit,
622 	},
623 	{
624 		.cmd = VDPA_CMD_DEV_NEW,
625 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
626 		.doit = vdpa_nl_cmd_dev_add_set_doit,
627 		.flags = GENL_ADMIN_PERM,
628 	},
629 	{
630 		.cmd = VDPA_CMD_DEV_DEL,
631 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
632 		.doit = vdpa_nl_cmd_dev_del_set_doit,
633 		.flags = GENL_ADMIN_PERM,
634 	},
635 	{
636 		.cmd = VDPA_CMD_DEV_GET,
637 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
638 		.doit = vdpa_nl_cmd_dev_get_doit,
639 		.dumpit = vdpa_nl_cmd_dev_get_dumpit,
640 	},
641 };
642 
643 static struct genl_family vdpa_nl_family __ro_after_init = {
644 	.name = VDPA_GENL_NAME,
645 	.version = VDPA_GENL_VERSION,
646 	.maxattr = VDPA_ATTR_MAX,
647 	.policy = vdpa_nl_policy,
648 	.netnsok = false,
649 	.module = THIS_MODULE,
650 	.ops = vdpa_nl_ops,
651 	.n_ops = ARRAY_SIZE(vdpa_nl_ops),
652 };
653 
654 static int vdpa_init(void)
655 {
656 	int err;
657 
658 	err = bus_register(&vdpa_bus);
659 	if (err)
660 		return err;
661 	err = genl_register_family(&vdpa_nl_family);
662 	if (err)
663 		goto err;
664 	return 0;
665 
666 err:
667 	bus_unregister(&vdpa_bus);
668 	return err;
669 }
670 
671 static void __exit vdpa_exit(void)
672 {
673 	genl_unregister_family(&vdpa_nl_family);
674 	bus_unregister(&vdpa_bus);
675 	ida_destroy(&vdpa_index_ida);
676 }
677 core_initcall(vdpa_init);
678 module_exit(vdpa_exit);
679 
680 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
681 MODULE_LICENSE("GPL v2");
682