xref: /openbmc/linux/drivers/vdpa/vdpa.c (revision 1f012283)
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 #include <linux/virtio_ids.h>
18 
19 static LIST_HEAD(mdev_head);
20 /* A global mutex that protects vdpa management device and device level operations. */
21 static DEFINE_MUTEX(vdpa_dev_mutex);
22 static DEFINE_IDA(vdpa_index_ida);
23 
24 static struct genl_family vdpa_nl_family;
25 
26 static int vdpa_dev_probe(struct device *d)
27 {
28 	struct vdpa_device *vdev = dev_to_vdpa(d);
29 	struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver);
30 	const struct vdpa_config_ops *ops = vdev->config;
31 	u32 max_num, min_num = 1;
32 	int ret = 0;
33 
34 	max_num = ops->get_vq_num_max(vdev);
35 	if (ops->get_vq_num_min)
36 		min_num = ops->get_vq_num_min(vdev);
37 	if (max_num < min_num)
38 		return -EINVAL;
39 
40 	if (drv && drv->probe)
41 		ret = drv->probe(vdev);
42 
43 	return ret;
44 }
45 
46 static void vdpa_dev_remove(struct device *d)
47 {
48 	struct vdpa_device *vdev = dev_to_vdpa(d);
49 	struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver);
50 
51 	if (drv && drv->remove)
52 		drv->remove(vdev);
53 }
54 
55 static struct bus_type vdpa_bus = {
56 	.name  = "vdpa",
57 	.probe = vdpa_dev_probe,
58 	.remove = vdpa_dev_remove,
59 };
60 
61 static void vdpa_release_dev(struct device *d)
62 {
63 	struct vdpa_device *vdev = dev_to_vdpa(d);
64 	const struct vdpa_config_ops *ops = vdev->config;
65 
66 	if (ops->free)
67 		ops->free(vdev);
68 
69 	ida_simple_remove(&vdpa_index_ida, vdev->index);
70 	mutex_destroy(&vdev->cf_mutex);
71 	kfree(vdev);
72 }
73 
74 /**
75  * __vdpa_alloc_device - allocate and initilaize a vDPA device
76  * This allows driver to some prepartion after device is
77  * initialized but before registered.
78  * @parent: the parent device
79  * @config: the bus operations that is supported by this device
80  * @size: size of the parent structure that contains private data
81  * @name: name of the vdpa device; optional.
82  * @use_va: indicate whether virtual address must be used by this device
83  *
84  * Driver should use vdpa_alloc_device() wrapper macro instead of
85  * using this directly.
86  *
87  * Return: Returns an error when parent/config/dma_dev is not set or fail to get
88  *	   ida.
89  */
90 struct vdpa_device *__vdpa_alloc_device(struct device *parent,
91 					const struct vdpa_config_ops *config,
92 					size_t size, const char *name,
93 					bool use_va)
94 {
95 	struct vdpa_device *vdev;
96 	int err = -EINVAL;
97 
98 	if (!config)
99 		goto err;
100 
101 	if (!!config->dma_map != !!config->dma_unmap)
102 		goto err;
103 
104 	/* It should only work for the device that use on-chip IOMMU */
105 	if (use_va && !(config->dma_map || config->set_map))
106 		goto err;
107 
108 	err = -ENOMEM;
109 	vdev = kzalloc(size, GFP_KERNEL);
110 	if (!vdev)
111 		goto err;
112 
113 	err = ida_alloc(&vdpa_index_ida, GFP_KERNEL);
114 	if (err < 0)
115 		goto err_ida;
116 
117 	vdev->dev.bus = &vdpa_bus;
118 	vdev->dev.parent = parent;
119 	vdev->dev.release = vdpa_release_dev;
120 	vdev->index = err;
121 	vdev->config = config;
122 	vdev->features_valid = false;
123 	vdev->use_va = use_va;
124 
125 	if (name)
126 		err = dev_set_name(&vdev->dev, "%s", name);
127 	else
128 		err = dev_set_name(&vdev->dev, "vdpa%u", vdev->index);
129 	if (err)
130 		goto err_name;
131 
132 	mutex_init(&vdev->cf_mutex);
133 	device_initialize(&vdev->dev);
134 
135 	return vdev;
136 
137 err_name:
138 	ida_simple_remove(&vdpa_index_ida, vdev->index);
139 err_ida:
140 	kfree(vdev);
141 err:
142 	return ERR_PTR(err);
143 }
144 EXPORT_SYMBOL_GPL(__vdpa_alloc_device);
145 
146 static int vdpa_name_match(struct device *dev, const void *data)
147 {
148 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
149 
150 	return (strcmp(dev_name(&vdev->dev), data) == 0);
151 }
152 
153 static int __vdpa_register_device(struct vdpa_device *vdev, int nvqs)
154 {
155 	struct device *dev;
156 
157 	vdev->nvqs = nvqs;
158 
159 	lockdep_assert_held(&vdpa_dev_mutex);
160 	dev = bus_find_device(&vdpa_bus, NULL, dev_name(&vdev->dev), vdpa_name_match);
161 	if (dev) {
162 		put_device(dev);
163 		return -EEXIST;
164 	}
165 	return device_add(&vdev->dev);
166 }
167 
168 /**
169  * _vdpa_register_device - register a vDPA device with vdpa lock held
170  * Caller must have a succeed call of vdpa_alloc_device() before.
171  * Caller must invoke this routine in the management device dev_add()
172  * callback after setting up valid mgmtdev for this vdpa device.
173  * @vdev: the vdpa device to be registered to vDPA bus
174  * @nvqs: number of virtqueues supported by this device
175  *
176  * Return: Returns an error when fail to add device to vDPA bus
177  */
178 int _vdpa_register_device(struct vdpa_device *vdev, int nvqs)
179 {
180 	if (!vdev->mdev)
181 		return -EINVAL;
182 
183 	return __vdpa_register_device(vdev, nvqs);
184 }
185 EXPORT_SYMBOL_GPL(_vdpa_register_device);
186 
187 /**
188  * vdpa_register_device - register a vDPA device
189  * Callers must have a succeed call of vdpa_alloc_device() before.
190  * @vdev: the vdpa device to be registered to vDPA bus
191  * @nvqs: number of virtqueues supported by this device
192  *
193  * Return: Returns an error when fail to add to vDPA bus
194  */
195 int vdpa_register_device(struct vdpa_device *vdev, int nvqs)
196 {
197 	int err;
198 
199 	mutex_lock(&vdpa_dev_mutex);
200 	err = __vdpa_register_device(vdev, nvqs);
201 	mutex_unlock(&vdpa_dev_mutex);
202 	return err;
203 }
204 EXPORT_SYMBOL_GPL(vdpa_register_device);
205 
206 /**
207  * _vdpa_unregister_device - unregister a vDPA device
208  * Caller must invoke this routine as part of management device dev_del()
209  * callback.
210  * @vdev: the vdpa device to be unregisted from vDPA bus
211  */
212 void _vdpa_unregister_device(struct vdpa_device *vdev)
213 {
214 	lockdep_assert_held(&vdpa_dev_mutex);
215 	WARN_ON(!vdev->mdev);
216 	device_unregister(&vdev->dev);
217 }
218 EXPORT_SYMBOL_GPL(_vdpa_unregister_device);
219 
220 /**
221  * vdpa_unregister_device - unregister a vDPA device
222  * @vdev: the vdpa device to be unregisted from vDPA bus
223  */
224 void vdpa_unregister_device(struct vdpa_device *vdev)
225 {
226 	mutex_lock(&vdpa_dev_mutex);
227 	device_unregister(&vdev->dev);
228 	mutex_unlock(&vdpa_dev_mutex);
229 }
230 EXPORT_SYMBOL_GPL(vdpa_unregister_device);
231 
232 /**
233  * __vdpa_register_driver - register a vDPA device driver
234  * @drv: the vdpa device driver to be registered
235  * @owner: module owner of the driver
236  *
237  * Return: Returns an err when fail to do the registration
238  */
239 int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner)
240 {
241 	drv->driver.bus = &vdpa_bus;
242 	drv->driver.owner = owner;
243 
244 	return driver_register(&drv->driver);
245 }
246 EXPORT_SYMBOL_GPL(__vdpa_register_driver);
247 
248 /**
249  * vdpa_unregister_driver - unregister a vDPA device driver
250  * @drv: the vdpa device driver to be unregistered
251  */
252 void vdpa_unregister_driver(struct vdpa_driver *drv)
253 {
254 	driver_unregister(&drv->driver);
255 }
256 EXPORT_SYMBOL_GPL(vdpa_unregister_driver);
257 
258 /**
259  * vdpa_mgmtdev_register - register a vdpa management device
260  *
261  * @mdev: Pointer to vdpa management device
262  * vdpa_mgmtdev_register() register a vdpa management device which supports
263  * vdpa device management.
264  * Return: Returns 0 on success or failure when required callback ops are not
265  *         initialized.
266  */
267 int vdpa_mgmtdev_register(struct vdpa_mgmt_dev *mdev)
268 {
269 	if (!mdev->device || !mdev->ops || !mdev->ops->dev_add || !mdev->ops->dev_del)
270 		return -EINVAL;
271 
272 	INIT_LIST_HEAD(&mdev->list);
273 	mutex_lock(&vdpa_dev_mutex);
274 	list_add_tail(&mdev->list, &mdev_head);
275 	mutex_unlock(&vdpa_dev_mutex);
276 	return 0;
277 }
278 EXPORT_SYMBOL_GPL(vdpa_mgmtdev_register);
279 
280 static int vdpa_match_remove(struct device *dev, void *data)
281 {
282 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
283 	struct vdpa_mgmt_dev *mdev = vdev->mdev;
284 
285 	if (mdev == data)
286 		mdev->ops->dev_del(mdev, vdev);
287 	return 0;
288 }
289 
290 void vdpa_mgmtdev_unregister(struct vdpa_mgmt_dev *mdev)
291 {
292 	mutex_lock(&vdpa_dev_mutex);
293 
294 	list_del(&mdev->list);
295 
296 	/* Filter out all the entries belong to this management device and delete it. */
297 	bus_for_each_dev(&vdpa_bus, NULL, mdev, vdpa_match_remove);
298 
299 	mutex_unlock(&vdpa_dev_mutex);
300 }
301 EXPORT_SYMBOL_GPL(vdpa_mgmtdev_unregister);
302 
303 /**
304  * vdpa_get_config - Get one or more device configuration fields.
305  * @vdev: vdpa device to operate on
306  * @offset: starting byte offset of the field
307  * @buf: buffer pointer to read to
308  * @len: length of the configuration fields in bytes
309  */
310 void vdpa_get_config(struct vdpa_device *vdev, unsigned int offset,
311 		     void *buf, unsigned int len)
312 {
313 	const struct vdpa_config_ops *ops = vdev->config;
314 
315 	mutex_lock(&vdev->cf_mutex);
316 	/*
317 	 * Config accesses aren't supposed to trigger before features are set.
318 	 * If it does happen we assume a legacy guest.
319 	 */
320 	if (!vdev->features_valid)
321 		vdpa_set_features(vdev, 0);
322 	ops->get_config(vdev, offset, buf, len);
323 	mutex_unlock(&vdev->cf_mutex);
324 }
325 EXPORT_SYMBOL_GPL(vdpa_get_config);
326 
327 /**
328  * vdpa_set_config - Set one or more device configuration fields.
329  * @vdev: vdpa device to operate on
330  * @offset: starting byte offset of the field
331  * @buf: buffer pointer to read from
332  * @length: length of the configuration fields in bytes
333  */
334 void vdpa_set_config(struct vdpa_device *vdev, unsigned int offset,
335 		     const void *buf, unsigned int length)
336 {
337 	mutex_lock(&vdev->cf_mutex);
338 	vdev->config->set_config(vdev, offset, buf, length);
339 	mutex_unlock(&vdev->cf_mutex);
340 }
341 EXPORT_SYMBOL_GPL(vdpa_set_config);
342 
343 static bool mgmtdev_handle_match(const struct vdpa_mgmt_dev *mdev,
344 				 const char *busname, const char *devname)
345 {
346 	/* Bus name is optional for simulated management device, so ignore the
347 	 * device with bus if bus attribute is provided.
348 	 */
349 	if ((busname && !mdev->device->bus) || (!busname && mdev->device->bus))
350 		return false;
351 
352 	if (!busname && strcmp(dev_name(mdev->device), devname) == 0)
353 		return true;
354 
355 	if (busname && (strcmp(mdev->device->bus->name, busname) == 0) &&
356 	    (strcmp(dev_name(mdev->device), devname) == 0))
357 		return true;
358 
359 	return false;
360 }
361 
362 static struct vdpa_mgmt_dev *vdpa_mgmtdev_get_from_attr(struct nlattr **attrs)
363 {
364 	struct vdpa_mgmt_dev *mdev;
365 	const char *busname = NULL;
366 	const char *devname;
367 
368 	if (!attrs[VDPA_ATTR_MGMTDEV_DEV_NAME])
369 		return ERR_PTR(-EINVAL);
370 	devname = nla_data(attrs[VDPA_ATTR_MGMTDEV_DEV_NAME]);
371 	if (attrs[VDPA_ATTR_MGMTDEV_BUS_NAME])
372 		busname = nla_data(attrs[VDPA_ATTR_MGMTDEV_BUS_NAME]);
373 
374 	list_for_each_entry(mdev, &mdev_head, list) {
375 		if (mgmtdev_handle_match(mdev, busname, devname))
376 			return mdev;
377 	}
378 	return ERR_PTR(-ENODEV);
379 }
380 
381 static int vdpa_nl_mgmtdev_handle_fill(struct sk_buff *msg, const struct vdpa_mgmt_dev *mdev)
382 {
383 	if (mdev->device->bus &&
384 	    nla_put_string(msg, VDPA_ATTR_MGMTDEV_BUS_NAME, mdev->device->bus->name))
385 		return -EMSGSIZE;
386 	if (nla_put_string(msg, VDPA_ATTR_MGMTDEV_DEV_NAME, dev_name(mdev->device)))
387 		return -EMSGSIZE;
388 	return 0;
389 }
390 
391 static int vdpa_mgmtdev_fill(const struct vdpa_mgmt_dev *mdev, struct sk_buff *msg,
392 			     u32 portid, u32 seq, int flags)
393 {
394 	u64 supported_classes = 0;
395 	void *hdr;
396 	int i = 0;
397 	int err;
398 
399 	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, VDPA_CMD_MGMTDEV_NEW);
400 	if (!hdr)
401 		return -EMSGSIZE;
402 	err = vdpa_nl_mgmtdev_handle_fill(msg, mdev);
403 	if (err)
404 		goto msg_err;
405 
406 	while (mdev->id_table[i].device) {
407 		supported_classes |= BIT(mdev->id_table[i].device);
408 		i++;
409 	}
410 
411 	if (nla_put_u64_64bit(msg, VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES,
412 			      supported_classes, VDPA_ATTR_UNSPEC)) {
413 		err = -EMSGSIZE;
414 		goto msg_err;
415 	}
416 
417 	genlmsg_end(msg, hdr);
418 	return 0;
419 
420 msg_err:
421 	genlmsg_cancel(msg, hdr);
422 	return err;
423 }
424 
425 static int vdpa_nl_cmd_mgmtdev_get_doit(struct sk_buff *skb, struct genl_info *info)
426 {
427 	struct vdpa_mgmt_dev *mdev;
428 	struct sk_buff *msg;
429 	int err;
430 
431 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
432 	if (!msg)
433 		return -ENOMEM;
434 
435 	mutex_lock(&vdpa_dev_mutex);
436 	mdev = vdpa_mgmtdev_get_from_attr(info->attrs);
437 	if (IS_ERR(mdev)) {
438 		mutex_unlock(&vdpa_dev_mutex);
439 		NL_SET_ERR_MSG_MOD(info->extack, "Fail to find the specified mgmt device");
440 		err = PTR_ERR(mdev);
441 		goto out;
442 	}
443 
444 	err = vdpa_mgmtdev_fill(mdev, msg, info->snd_portid, info->snd_seq, 0);
445 	mutex_unlock(&vdpa_dev_mutex);
446 	if (err)
447 		goto out;
448 	err = genlmsg_reply(msg, info);
449 	return err;
450 
451 out:
452 	nlmsg_free(msg);
453 	return err;
454 }
455 
456 static int
457 vdpa_nl_cmd_mgmtdev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
458 {
459 	struct vdpa_mgmt_dev *mdev;
460 	int start = cb->args[0];
461 	int idx = 0;
462 	int err;
463 
464 	mutex_lock(&vdpa_dev_mutex);
465 	list_for_each_entry(mdev, &mdev_head, list) {
466 		if (idx < start) {
467 			idx++;
468 			continue;
469 		}
470 		err = vdpa_mgmtdev_fill(mdev, msg, NETLINK_CB(cb->skb).portid,
471 					cb->nlh->nlmsg_seq, NLM_F_MULTI);
472 		if (err)
473 			goto out;
474 		idx++;
475 	}
476 out:
477 	mutex_unlock(&vdpa_dev_mutex);
478 	cb->args[0] = idx;
479 	return msg->len;
480 }
481 
482 #define VDPA_DEV_NET_ATTRS_MASK ((1 << VDPA_ATTR_DEV_NET_CFG_MACADDR) | \
483 				 (1 << VDPA_ATTR_DEV_NET_CFG_MTU))
484 
485 static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *info)
486 {
487 	struct vdpa_dev_set_config config = {};
488 	struct nlattr **nl_attrs = info->attrs;
489 	struct vdpa_mgmt_dev *mdev;
490 	const u8 *macaddr;
491 	const char *name;
492 	int err = 0;
493 
494 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
495 		return -EINVAL;
496 
497 	name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
498 
499 	if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR]) {
500 		macaddr = nla_data(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR]);
501 		memcpy(config.net.mac, macaddr, sizeof(config.net.mac));
502 		config.mask |= (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR);
503 	}
504 	if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MTU]) {
505 		config.net.mtu =
506 			nla_get_u16(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MTU]);
507 		config.mask |= (1 << VDPA_ATTR_DEV_NET_CFG_MTU);
508 	}
509 
510 	/* Skip checking capability if user didn't prefer to configure any
511 	 * device networking attributes. It is likely that user might have used
512 	 * a device specific method to configure such attributes or using device
513 	 * default attributes.
514 	 */
515 	if ((config.mask & VDPA_DEV_NET_ATTRS_MASK) &&
516 	    !netlink_capable(skb, CAP_NET_ADMIN))
517 		return -EPERM;
518 
519 	mutex_lock(&vdpa_dev_mutex);
520 	mdev = vdpa_mgmtdev_get_from_attr(info->attrs);
521 	if (IS_ERR(mdev)) {
522 		NL_SET_ERR_MSG_MOD(info->extack, "Fail to find the specified management device");
523 		err = PTR_ERR(mdev);
524 		goto err;
525 	}
526 	if ((config.mask & mdev->config_attr_mask) != config.mask) {
527 		NL_SET_ERR_MSG_MOD(info->extack,
528 				   "All provided attributes are not supported");
529 		err = -EOPNOTSUPP;
530 		goto err;
531 	}
532 
533 	err = mdev->ops->dev_add(mdev, name, &config);
534 err:
535 	mutex_unlock(&vdpa_dev_mutex);
536 	return err;
537 }
538 
539 static int vdpa_nl_cmd_dev_del_set_doit(struct sk_buff *skb, struct genl_info *info)
540 {
541 	struct vdpa_mgmt_dev *mdev;
542 	struct vdpa_device *vdev;
543 	struct device *dev;
544 	const char *name;
545 	int err = 0;
546 
547 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
548 		return -EINVAL;
549 	name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
550 
551 	mutex_lock(&vdpa_dev_mutex);
552 	dev = bus_find_device(&vdpa_bus, NULL, name, vdpa_name_match);
553 	if (!dev) {
554 		NL_SET_ERR_MSG_MOD(info->extack, "device not found");
555 		err = -ENODEV;
556 		goto dev_err;
557 	}
558 	vdev = container_of(dev, struct vdpa_device, dev);
559 	if (!vdev->mdev) {
560 		NL_SET_ERR_MSG_MOD(info->extack, "Only user created device can be deleted by user");
561 		err = -EINVAL;
562 		goto mdev_err;
563 	}
564 	mdev = vdev->mdev;
565 	mdev->ops->dev_del(mdev, vdev);
566 mdev_err:
567 	put_device(dev);
568 dev_err:
569 	mutex_unlock(&vdpa_dev_mutex);
570 	return err;
571 }
572 
573 static int
574 vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
575 	      int flags, struct netlink_ext_ack *extack)
576 {
577 	u16 max_vq_size;
578 	u16 min_vq_size = 1;
579 	u32 device_id;
580 	u32 vendor_id;
581 	void *hdr;
582 	int err;
583 
584 	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, VDPA_CMD_DEV_NEW);
585 	if (!hdr)
586 		return -EMSGSIZE;
587 
588 	err = vdpa_nl_mgmtdev_handle_fill(msg, vdev->mdev);
589 	if (err)
590 		goto msg_err;
591 
592 	device_id = vdev->config->get_device_id(vdev);
593 	vendor_id = vdev->config->get_vendor_id(vdev);
594 	max_vq_size = vdev->config->get_vq_num_max(vdev);
595 	if (vdev->config->get_vq_num_min)
596 		min_vq_size = vdev->config->get_vq_num_min(vdev);
597 
598 	err = -EMSGSIZE;
599 	if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev)))
600 		goto msg_err;
601 	if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id))
602 		goto msg_err;
603 	if (nla_put_u32(msg, VDPA_ATTR_DEV_VENDOR_ID, vendor_id))
604 		goto msg_err;
605 	if (nla_put_u32(msg, VDPA_ATTR_DEV_MAX_VQS, vdev->nvqs))
606 		goto msg_err;
607 	if (nla_put_u16(msg, VDPA_ATTR_DEV_MAX_VQ_SIZE, max_vq_size))
608 		goto msg_err;
609 	if (nla_put_u16(msg, VDPA_ATTR_DEV_MIN_VQ_SIZE, min_vq_size))
610 		goto msg_err;
611 
612 	genlmsg_end(msg, hdr);
613 	return 0;
614 
615 msg_err:
616 	genlmsg_cancel(msg, hdr);
617 	return err;
618 }
619 
620 static int vdpa_nl_cmd_dev_get_doit(struct sk_buff *skb, struct genl_info *info)
621 {
622 	struct vdpa_device *vdev;
623 	struct sk_buff *msg;
624 	const char *devname;
625 	struct device *dev;
626 	int err;
627 
628 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
629 		return -EINVAL;
630 	devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
631 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
632 	if (!msg)
633 		return -ENOMEM;
634 
635 	mutex_lock(&vdpa_dev_mutex);
636 	dev = bus_find_device(&vdpa_bus, NULL, devname, vdpa_name_match);
637 	if (!dev) {
638 		NL_SET_ERR_MSG_MOD(info->extack, "device not found");
639 		err = -ENODEV;
640 		goto err;
641 	}
642 	vdev = container_of(dev, struct vdpa_device, dev);
643 	if (!vdev->mdev) {
644 		err = -EINVAL;
645 		goto mdev_err;
646 	}
647 	err = vdpa_dev_fill(vdev, msg, info->snd_portid, info->snd_seq, 0, info->extack);
648 	if (!err)
649 		err = genlmsg_reply(msg, info);
650 mdev_err:
651 	put_device(dev);
652 err:
653 	mutex_unlock(&vdpa_dev_mutex);
654 	if (err)
655 		nlmsg_free(msg);
656 	return err;
657 }
658 
659 struct vdpa_dev_dump_info {
660 	struct sk_buff *msg;
661 	struct netlink_callback *cb;
662 	int start_idx;
663 	int idx;
664 };
665 
666 static int vdpa_dev_dump(struct device *dev, void *data)
667 {
668 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
669 	struct vdpa_dev_dump_info *info = data;
670 	int err;
671 
672 	if (!vdev->mdev)
673 		return 0;
674 	if (info->idx < info->start_idx) {
675 		info->idx++;
676 		return 0;
677 	}
678 	err = vdpa_dev_fill(vdev, info->msg, NETLINK_CB(info->cb->skb).portid,
679 			    info->cb->nlh->nlmsg_seq, NLM_F_MULTI, info->cb->extack);
680 	if (err)
681 		return err;
682 
683 	info->idx++;
684 	return 0;
685 }
686 
687 static int vdpa_nl_cmd_dev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
688 {
689 	struct vdpa_dev_dump_info info;
690 
691 	info.msg = msg;
692 	info.cb = cb;
693 	info.start_idx = cb->args[0];
694 	info.idx = 0;
695 
696 	mutex_lock(&vdpa_dev_mutex);
697 	bus_for_each_dev(&vdpa_bus, NULL, &info, vdpa_dev_dump);
698 	mutex_unlock(&vdpa_dev_mutex);
699 	cb->args[0] = info.idx;
700 	return msg->len;
701 }
702 
703 static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev,
704 				       struct sk_buff *msg, u64 features,
705 				       const struct virtio_net_config *config)
706 {
707 	u16 val_u16;
708 
709 	if ((features & (1ULL << VIRTIO_NET_F_MQ)) == 0)
710 		return 0;
711 
712 	val_u16 = le16_to_cpu(config->max_virtqueue_pairs);
713 	return nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, val_u16);
714 }
715 
716 static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg)
717 {
718 	struct virtio_net_config config = {};
719 	u64 features;
720 	u16 val_u16;
721 
722 	vdpa_get_config(vdev, 0, &config, sizeof(config));
723 
724 	if (nla_put(msg, VDPA_ATTR_DEV_NET_CFG_MACADDR, sizeof(config.mac),
725 		    config.mac))
726 		return -EMSGSIZE;
727 
728 	val_u16 = le16_to_cpu(config.status);
729 	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16))
730 		return -EMSGSIZE;
731 
732 	val_u16 = le16_to_cpu(config.mtu);
733 	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16))
734 		return -EMSGSIZE;
735 
736 	features = vdev->config->get_features(vdev);
737 
738 	return vdpa_dev_net_mq_config_fill(vdev, msg, features, &config);
739 }
740 
741 static int
742 vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
743 		     int flags, struct netlink_ext_ack *extack)
744 {
745 	u32 device_id;
746 	void *hdr;
747 	int err;
748 
749 	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags,
750 			  VDPA_CMD_DEV_CONFIG_GET);
751 	if (!hdr)
752 		return -EMSGSIZE;
753 
754 	if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev))) {
755 		err = -EMSGSIZE;
756 		goto msg_err;
757 	}
758 
759 	device_id = vdev->config->get_device_id(vdev);
760 	if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id)) {
761 		err = -EMSGSIZE;
762 		goto msg_err;
763 	}
764 
765 	switch (device_id) {
766 	case VIRTIO_ID_NET:
767 		err = vdpa_dev_net_config_fill(vdev, msg);
768 		break;
769 	default:
770 		err = -EOPNOTSUPP;
771 		break;
772 	}
773 	if (err)
774 		goto msg_err;
775 
776 	genlmsg_end(msg, hdr);
777 	return 0;
778 
779 msg_err:
780 	genlmsg_cancel(msg, hdr);
781 	return err;
782 }
783 
784 static int vdpa_nl_cmd_dev_config_get_doit(struct sk_buff *skb, struct genl_info *info)
785 {
786 	struct vdpa_device *vdev;
787 	struct sk_buff *msg;
788 	const char *devname;
789 	struct device *dev;
790 	int err;
791 
792 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
793 		return -EINVAL;
794 	devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
795 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
796 	if (!msg)
797 		return -ENOMEM;
798 
799 	mutex_lock(&vdpa_dev_mutex);
800 	dev = bus_find_device(&vdpa_bus, NULL, devname, vdpa_name_match);
801 	if (!dev) {
802 		NL_SET_ERR_MSG_MOD(info->extack, "device not found");
803 		err = -ENODEV;
804 		goto dev_err;
805 	}
806 	vdev = container_of(dev, struct vdpa_device, dev);
807 	if (!vdev->mdev) {
808 		NL_SET_ERR_MSG_MOD(info->extack, "unmanaged vdpa device");
809 		err = -EINVAL;
810 		goto mdev_err;
811 	}
812 	err = vdpa_dev_config_fill(vdev, msg, info->snd_portid, info->snd_seq,
813 				   0, info->extack);
814 	if (!err)
815 		err = genlmsg_reply(msg, info);
816 
817 mdev_err:
818 	put_device(dev);
819 dev_err:
820 	mutex_unlock(&vdpa_dev_mutex);
821 	if (err)
822 		nlmsg_free(msg);
823 	return err;
824 }
825 
826 static int vdpa_dev_config_dump(struct device *dev, void *data)
827 {
828 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
829 	struct vdpa_dev_dump_info *info = data;
830 	int err;
831 
832 	if (!vdev->mdev)
833 		return 0;
834 	if (info->idx < info->start_idx) {
835 		info->idx++;
836 		return 0;
837 	}
838 	err = vdpa_dev_config_fill(vdev, info->msg, NETLINK_CB(info->cb->skb).portid,
839 				   info->cb->nlh->nlmsg_seq, NLM_F_MULTI,
840 				   info->cb->extack);
841 	if (err)
842 		return err;
843 
844 	info->idx++;
845 	return 0;
846 }
847 
848 static int
849 vdpa_nl_cmd_dev_config_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
850 {
851 	struct vdpa_dev_dump_info info;
852 
853 	info.msg = msg;
854 	info.cb = cb;
855 	info.start_idx = cb->args[0];
856 	info.idx = 0;
857 
858 	mutex_lock(&vdpa_dev_mutex);
859 	bus_for_each_dev(&vdpa_bus, NULL, &info, vdpa_dev_config_dump);
860 	mutex_unlock(&vdpa_dev_mutex);
861 	cb->args[0] = info.idx;
862 	return msg->len;
863 }
864 
865 static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = {
866 	[VDPA_ATTR_MGMTDEV_BUS_NAME] = { .type = NLA_NUL_STRING },
867 	[VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING },
868 	[VDPA_ATTR_DEV_NAME] = { .type = NLA_STRING },
869 	[VDPA_ATTR_DEV_NET_CFG_MACADDR] = NLA_POLICY_ETH_ADDR,
870 	/* virtio spec 1.1 section 5.1.4.1 for valid MTU range */
871 	[VDPA_ATTR_DEV_NET_CFG_MTU] = NLA_POLICY_MIN(NLA_U16, 68),
872 };
873 
874 static const struct genl_ops vdpa_nl_ops[] = {
875 	{
876 		.cmd = VDPA_CMD_MGMTDEV_GET,
877 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
878 		.doit = vdpa_nl_cmd_mgmtdev_get_doit,
879 		.dumpit = vdpa_nl_cmd_mgmtdev_get_dumpit,
880 	},
881 	{
882 		.cmd = VDPA_CMD_DEV_NEW,
883 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
884 		.doit = vdpa_nl_cmd_dev_add_set_doit,
885 		.flags = GENL_ADMIN_PERM,
886 	},
887 	{
888 		.cmd = VDPA_CMD_DEV_DEL,
889 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
890 		.doit = vdpa_nl_cmd_dev_del_set_doit,
891 		.flags = GENL_ADMIN_PERM,
892 	},
893 	{
894 		.cmd = VDPA_CMD_DEV_GET,
895 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
896 		.doit = vdpa_nl_cmd_dev_get_doit,
897 		.dumpit = vdpa_nl_cmd_dev_get_dumpit,
898 	},
899 	{
900 		.cmd = VDPA_CMD_DEV_CONFIG_GET,
901 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
902 		.doit = vdpa_nl_cmd_dev_config_get_doit,
903 		.dumpit = vdpa_nl_cmd_dev_config_get_dumpit,
904 	},
905 };
906 
907 static struct genl_family vdpa_nl_family __ro_after_init = {
908 	.name = VDPA_GENL_NAME,
909 	.version = VDPA_GENL_VERSION,
910 	.maxattr = VDPA_ATTR_MAX,
911 	.policy = vdpa_nl_policy,
912 	.netnsok = false,
913 	.module = THIS_MODULE,
914 	.ops = vdpa_nl_ops,
915 	.n_ops = ARRAY_SIZE(vdpa_nl_ops),
916 };
917 
918 static int vdpa_init(void)
919 {
920 	int err;
921 
922 	err = bus_register(&vdpa_bus);
923 	if (err)
924 		return err;
925 	err = genl_register_family(&vdpa_nl_family);
926 	if (err)
927 		goto err;
928 	return 0;
929 
930 err:
931 	bus_unregister(&vdpa_bus);
932 	return err;
933 }
934 
935 static void __exit vdpa_exit(void)
936 {
937 	genl_unregister_family(&vdpa_nl_family);
938 	bus_unregister(&vdpa_bus);
939 	ida_destroy(&vdpa_index_ida);
940 }
941 core_initcall(vdpa_init);
942 module_exit(vdpa_exit);
943 
944 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
945 MODULE_LICENSE("GPL v2");
946