xref: /linux/drivers/vdpa/vdpa.c (revision 6224db7881936c8e1c3b352b5debbbbd8856911a)
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 DECLARE_RWSEM(vdpa_dev_lock);
22 static DEFINE_IDA(vdpa_index_ida);
23 
24 void vdpa_set_status(struct vdpa_device *vdev, u8 status)
25 {
26 	down_write(&vdev->cf_lock);
27 	vdev->config->set_status(vdev, status);
28 	up_write(&vdev->cf_lock);
29 }
30 EXPORT_SYMBOL(vdpa_set_status);
31 
32 static struct genl_family vdpa_nl_family;
33 
34 static int vdpa_dev_probe(struct device *d)
35 {
36 	struct vdpa_device *vdev = dev_to_vdpa(d);
37 	struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver);
38 	const struct vdpa_config_ops *ops = vdev->config;
39 	u32 max_num, min_num = 1;
40 	int ret = 0;
41 
42 	max_num = ops->get_vq_num_max(vdev);
43 	if (ops->get_vq_num_min)
44 		min_num = ops->get_vq_num_min(vdev);
45 	if (max_num < min_num)
46 		return -EINVAL;
47 
48 	if (drv && drv->probe)
49 		ret = drv->probe(vdev);
50 
51 	return ret;
52 }
53 
54 static void vdpa_dev_remove(struct device *d)
55 {
56 	struct vdpa_device *vdev = dev_to_vdpa(d);
57 	struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver);
58 
59 	if (drv && drv->remove)
60 		drv->remove(vdev);
61 }
62 
63 static int vdpa_dev_match(struct device *dev, struct device_driver *drv)
64 {
65 	struct vdpa_device *vdev = dev_to_vdpa(dev);
66 
67 	/* Check override first, and if set, only use the named driver */
68 	if (vdev->driver_override)
69 		return strcmp(vdev->driver_override, drv->name) == 0;
70 
71 	/* Currently devices must be supported by all vDPA bus drivers */
72 	return 1;
73 }
74 
75 static ssize_t driver_override_store(struct device *dev,
76 				     struct device_attribute *attr,
77 				     const char *buf, size_t count)
78 {
79 	struct vdpa_device *vdev = dev_to_vdpa(dev);
80 	int ret;
81 
82 	ret = driver_set_override(dev, &vdev->driver_override, buf, count);
83 	if (ret)
84 		return ret;
85 
86 	return count;
87 }
88 
89 static ssize_t driver_override_show(struct device *dev,
90 				    struct device_attribute *attr, char *buf)
91 {
92 	struct vdpa_device *vdev = dev_to_vdpa(dev);
93 	ssize_t len;
94 
95 	device_lock(dev);
96 	len = snprintf(buf, PAGE_SIZE, "%s\n", vdev->driver_override);
97 	device_unlock(dev);
98 
99 	return len;
100 }
101 static DEVICE_ATTR_RW(driver_override);
102 
103 static struct attribute *vdpa_dev_attrs[] = {
104 	&dev_attr_driver_override.attr,
105 	NULL,
106 };
107 
108 static const struct attribute_group vdpa_dev_group = {
109 	.attrs  = vdpa_dev_attrs,
110 };
111 __ATTRIBUTE_GROUPS(vdpa_dev);
112 
113 static struct bus_type vdpa_bus = {
114 	.name  = "vdpa",
115 	.dev_groups = vdpa_dev_groups,
116 	.match = vdpa_dev_match,
117 	.probe = vdpa_dev_probe,
118 	.remove = vdpa_dev_remove,
119 };
120 
121 static void vdpa_release_dev(struct device *d)
122 {
123 	struct vdpa_device *vdev = dev_to_vdpa(d);
124 	const struct vdpa_config_ops *ops = vdev->config;
125 
126 	if (ops->free)
127 		ops->free(vdev);
128 
129 	ida_simple_remove(&vdpa_index_ida, vdev->index);
130 	kfree(vdev->driver_override);
131 	kfree(vdev);
132 }
133 
134 /**
135  * __vdpa_alloc_device - allocate and initilaize a vDPA device
136  * This allows driver to some prepartion after device is
137  * initialized but before registered.
138  * @parent: the parent device
139  * @config: the bus operations that is supported by this device
140  * @ngroups: number of groups supported by this device
141  * @nas: number of address spaces supported by this device
142  * @size: size of the parent structure that contains private data
143  * @name: name of the vdpa device; optional.
144  * @use_va: indicate whether virtual address must be used by this device
145  *
146  * Driver should use vdpa_alloc_device() wrapper macro instead of
147  * using this directly.
148  *
149  * Return: Returns an error when parent/config/dma_dev is not set or fail to get
150  *	   ida.
151  */
152 struct vdpa_device *__vdpa_alloc_device(struct device *parent,
153 					const struct vdpa_config_ops *config,
154 					unsigned int ngroups, unsigned int nas,
155 					size_t size, const char *name,
156 					bool use_va)
157 {
158 	struct vdpa_device *vdev;
159 	int err = -EINVAL;
160 
161 	if (!config)
162 		goto err;
163 
164 	if (!!config->dma_map != !!config->dma_unmap)
165 		goto err;
166 
167 	/* It should only work for the device that use on-chip IOMMU */
168 	if (use_va && !(config->dma_map || config->set_map))
169 		goto err;
170 
171 	err = -ENOMEM;
172 	vdev = kzalloc(size, GFP_KERNEL);
173 	if (!vdev)
174 		goto err;
175 
176 	err = ida_alloc(&vdpa_index_ida, GFP_KERNEL);
177 	if (err < 0)
178 		goto err_ida;
179 
180 	vdev->dev.bus = &vdpa_bus;
181 	vdev->dev.parent = parent;
182 	vdev->dev.release = vdpa_release_dev;
183 	vdev->index = err;
184 	vdev->config = config;
185 	vdev->features_valid = false;
186 	vdev->use_va = use_va;
187 	vdev->ngroups = ngroups;
188 	vdev->nas = nas;
189 
190 	if (name)
191 		err = dev_set_name(&vdev->dev, "%s", name);
192 	else
193 		err = dev_set_name(&vdev->dev, "vdpa%u", vdev->index);
194 	if (err)
195 		goto err_name;
196 
197 	init_rwsem(&vdev->cf_lock);
198 	device_initialize(&vdev->dev);
199 
200 	return vdev;
201 
202 err_name:
203 	ida_simple_remove(&vdpa_index_ida, vdev->index);
204 err_ida:
205 	kfree(vdev);
206 err:
207 	return ERR_PTR(err);
208 }
209 EXPORT_SYMBOL_GPL(__vdpa_alloc_device);
210 
211 static int vdpa_name_match(struct device *dev, const void *data)
212 {
213 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
214 
215 	return (strcmp(dev_name(&vdev->dev), data) == 0);
216 }
217 
218 static int __vdpa_register_device(struct vdpa_device *vdev, u32 nvqs)
219 {
220 	struct device *dev;
221 
222 	vdev->nvqs = nvqs;
223 
224 	lockdep_assert_held(&vdpa_dev_lock);
225 	dev = bus_find_device(&vdpa_bus, NULL, dev_name(&vdev->dev), vdpa_name_match);
226 	if (dev) {
227 		put_device(dev);
228 		return -EEXIST;
229 	}
230 	return device_add(&vdev->dev);
231 }
232 
233 /**
234  * _vdpa_register_device - register a vDPA device with vdpa lock held
235  * Caller must have a succeed call of vdpa_alloc_device() before.
236  * Caller must invoke this routine in the management device dev_add()
237  * callback after setting up valid mgmtdev for this vdpa device.
238  * @vdev: the vdpa device to be registered to vDPA bus
239  * @nvqs: number of virtqueues supported by this device
240  *
241  * Return: Returns an error when fail to add device to vDPA bus
242  */
243 int _vdpa_register_device(struct vdpa_device *vdev, u32 nvqs)
244 {
245 	if (!vdev->mdev)
246 		return -EINVAL;
247 
248 	return __vdpa_register_device(vdev, nvqs);
249 }
250 EXPORT_SYMBOL_GPL(_vdpa_register_device);
251 
252 /**
253  * vdpa_register_device - register a vDPA device
254  * Callers must have a succeed call of vdpa_alloc_device() before.
255  * @vdev: the vdpa device to be registered to vDPA bus
256  * @nvqs: number of virtqueues supported by this device
257  *
258  * Return: Returns an error when fail to add to vDPA bus
259  */
260 int vdpa_register_device(struct vdpa_device *vdev, u32 nvqs)
261 {
262 	int err;
263 
264 	down_write(&vdpa_dev_lock);
265 	err = __vdpa_register_device(vdev, nvqs);
266 	up_write(&vdpa_dev_lock);
267 	return err;
268 }
269 EXPORT_SYMBOL_GPL(vdpa_register_device);
270 
271 /**
272  * _vdpa_unregister_device - unregister a vDPA device
273  * Caller must invoke this routine as part of management device dev_del()
274  * callback.
275  * @vdev: the vdpa device to be unregisted from vDPA bus
276  */
277 void _vdpa_unregister_device(struct vdpa_device *vdev)
278 {
279 	lockdep_assert_held(&vdpa_dev_lock);
280 	WARN_ON(!vdev->mdev);
281 	device_unregister(&vdev->dev);
282 }
283 EXPORT_SYMBOL_GPL(_vdpa_unregister_device);
284 
285 /**
286  * vdpa_unregister_device - unregister a vDPA device
287  * @vdev: the vdpa device to be unregisted from vDPA bus
288  */
289 void vdpa_unregister_device(struct vdpa_device *vdev)
290 {
291 	down_write(&vdpa_dev_lock);
292 	device_unregister(&vdev->dev);
293 	up_write(&vdpa_dev_lock);
294 }
295 EXPORT_SYMBOL_GPL(vdpa_unregister_device);
296 
297 /**
298  * __vdpa_register_driver - register a vDPA device driver
299  * @drv: the vdpa device driver to be registered
300  * @owner: module owner of the driver
301  *
302  * Return: Returns an err when fail to do the registration
303  */
304 int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner)
305 {
306 	drv->driver.bus = &vdpa_bus;
307 	drv->driver.owner = owner;
308 
309 	return driver_register(&drv->driver);
310 }
311 EXPORT_SYMBOL_GPL(__vdpa_register_driver);
312 
313 /**
314  * vdpa_unregister_driver - unregister a vDPA device driver
315  * @drv: the vdpa device driver to be unregistered
316  */
317 void vdpa_unregister_driver(struct vdpa_driver *drv)
318 {
319 	driver_unregister(&drv->driver);
320 }
321 EXPORT_SYMBOL_GPL(vdpa_unregister_driver);
322 
323 /**
324  * vdpa_mgmtdev_register - register a vdpa management device
325  *
326  * @mdev: Pointer to vdpa management device
327  * vdpa_mgmtdev_register() register a vdpa management device which supports
328  * vdpa device management.
329  * Return: Returns 0 on success or failure when required callback ops are not
330  *         initialized.
331  */
332 int vdpa_mgmtdev_register(struct vdpa_mgmt_dev *mdev)
333 {
334 	if (!mdev->device || !mdev->ops || !mdev->ops->dev_add || !mdev->ops->dev_del)
335 		return -EINVAL;
336 
337 	INIT_LIST_HEAD(&mdev->list);
338 	down_write(&vdpa_dev_lock);
339 	list_add_tail(&mdev->list, &mdev_head);
340 	up_write(&vdpa_dev_lock);
341 	return 0;
342 }
343 EXPORT_SYMBOL_GPL(vdpa_mgmtdev_register);
344 
345 static int vdpa_match_remove(struct device *dev, void *data)
346 {
347 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
348 	struct vdpa_mgmt_dev *mdev = vdev->mdev;
349 
350 	if (mdev == data)
351 		mdev->ops->dev_del(mdev, vdev);
352 	return 0;
353 }
354 
355 void vdpa_mgmtdev_unregister(struct vdpa_mgmt_dev *mdev)
356 {
357 	down_write(&vdpa_dev_lock);
358 
359 	list_del(&mdev->list);
360 
361 	/* Filter out all the entries belong to this management device and delete it. */
362 	bus_for_each_dev(&vdpa_bus, NULL, mdev, vdpa_match_remove);
363 
364 	up_write(&vdpa_dev_lock);
365 }
366 EXPORT_SYMBOL_GPL(vdpa_mgmtdev_unregister);
367 
368 static void vdpa_get_config_unlocked(struct vdpa_device *vdev,
369 				     unsigned int offset,
370 				     void *buf, unsigned int len)
371 {
372 	const struct vdpa_config_ops *ops = vdev->config;
373 
374 	/*
375 	 * Config accesses aren't supposed to trigger before features are set.
376 	 * If it does happen we assume a legacy guest.
377 	 */
378 	if (!vdev->features_valid)
379 		vdpa_set_features_unlocked(vdev, 0);
380 	ops->get_config(vdev, offset, buf, len);
381 }
382 
383 /**
384  * vdpa_get_config - Get one or more device configuration fields.
385  * @vdev: vdpa device to operate on
386  * @offset: starting byte offset of the field
387  * @buf: buffer pointer to read to
388  * @len: length of the configuration fields in bytes
389  */
390 void vdpa_get_config(struct vdpa_device *vdev, unsigned int offset,
391 		     void *buf, unsigned int len)
392 {
393 	down_read(&vdev->cf_lock);
394 	vdpa_get_config_unlocked(vdev, offset, buf, len);
395 	up_read(&vdev->cf_lock);
396 }
397 EXPORT_SYMBOL_GPL(vdpa_get_config);
398 
399 /**
400  * vdpa_set_config - Set one or more device configuration fields.
401  * @vdev: vdpa device to operate on
402  * @offset: starting byte offset of the field
403  * @buf: buffer pointer to read from
404  * @length: length of the configuration fields in bytes
405  */
406 void vdpa_set_config(struct vdpa_device *vdev, unsigned int offset,
407 		     const void *buf, unsigned int length)
408 {
409 	down_write(&vdev->cf_lock);
410 	vdev->config->set_config(vdev, offset, buf, length);
411 	up_write(&vdev->cf_lock);
412 }
413 EXPORT_SYMBOL_GPL(vdpa_set_config);
414 
415 static bool mgmtdev_handle_match(const struct vdpa_mgmt_dev *mdev,
416 				 const char *busname, const char *devname)
417 {
418 	/* Bus name is optional for simulated management device, so ignore the
419 	 * device with bus if bus attribute is provided.
420 	 */
421 	if ((busname && !mdev->device->bus) || (!busname && mdev->device->bus))
422 		return false;
423 
424 	if (!busname && strcmp(dev_name(mdev->device), devname) == 0)
425 		return true;
426 
427 	if (busname && (strcmp(mdev->device->bus->name, busname) == 0) &&
428 	    (strcmp(dev_name(mdev->device), devname) == 0))
429 		return true;
430 
431 	return false;
432 }
433 
434 static struct vdpa_mgmt_dev *vdpa_mgmtdev_get_from_attr(struct nlattr **attrs)
435 {
436 	struct vdpa_mgmt_dev *mdev;
437 	const char *busname = NULL;
438 	const char *devname;
439 
440 	if (!attrs[VDPA_ATTR_MGMTDEV_DEV_NAME])
441 		return ERR_PTR(-EINVAL);
442 	devname = nla_data(attrs[VDPA_ATTR_MGMTDEV_DEV_NAME]);
443 	if (attrs[VDPA_ATTR_MGMTDEV_BUS_NAME])
444 		busname = nla_data(attrs[VDPA_ATTR_MGMTDEV_BUS_NAME]);
445 
446 	list_for_each_entry(mdev, &mdev_head, list) {
447 		if (mgmtdev_handle_match(mdev, busname, devname))
448 			return mdev;
449 	}
450 	return ERR_PTR(-ENODEV);
451 }
452 
453 static int vdpa_nl_mgmtdev_handle_fill(struct sk_buff *msg, const struct vdpa_mgmt_dev *mdev)
454 {
455 	if (mdev->device->bus &&
456 	    nla_put_string(msg, VDPA_ATTR_MGMTDEV_BUS_NAME, mdev->device->bus->name))
457 		return -EMSGSIZE;
458 	if (nla_put_string(msg, VDPA_ATTR_MGMTDEV_DEV_NAME, dev_name(mdev->device)))
459 		return -EMSGSIZE;
460 	return 0;
461 }
462 
463 static int vdpa_mgmtdev_fill(const struct vdpa_mgmt_dev *mdev, struct sk_buff *msg,
464 			     u32 portid, u32 seq, int flags)
465 {
466 	u64 supported_classes = 0;
467 	void *hdr;
468 	int i = 0;
469 	int err;
470 
471 	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, VDPA_CMD_MGMTDEV_NEW);
472 	if (!hdr)
473 		return -EMSGSIZE;
474 	err = vdpa_nl_mgmtdev_handle_fill(msg, mdev);
475 	if (err)
476 		goto msg_err;
477 
478 	while (mdev->id_table[i].device) {
479 		if (mdev->id_table[i].device <= 63)
480 			supported_classes |= BIT_ULL(mdev->id_table[i].device);
481 		i++;
482 	}
483 
484 	if (nla_put_u64_64bit(msg, VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES,
485 			      supported_classes, VDPA_ATTR_UNSPEC)) {
486 		err = -EMSGSIZE;
487 		goto msg_err;
488 	}
489 	if (nla_put_u32(msg, VDPA_ATTR_DEV_MGMTDEV_MAX_VQS,
490 			mdev->max_supported_vqs)) {
491 		err = -EMSGSIZE;
492 		goto msg_err;
493 	}
494 	if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_SUPPORTED_FEATURES,
495 			      mdev->supported_features, VDPA_ATTR_PAD)) {
496 		err = -EMSGSIZE;
497 		goto msg_err;
498 	}
499 
500 	genlmsg_end(msg, hdr);
501 	return 0;
502 
503 msg_err:
504 	genlmsg_cancel(msg, hdr);
505 	return err;
506 }
507 
508 static int vdpa_nl_cmd_mgmtdev_get_doit(struct sk_buff *skb, struct genl_info *info)
509 {
510 	struct vdpa_mgmt_dev *mdev;
511 	struct sk_buff *msg;
512 	int err;
513 
514 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
515 	if (!msg)
516 		return -ENOMEM;
517 
518 	down_read(&vdpa_dev_lock);
519 	mdev = vdpa_mgmtdev_get_from_attr(info->attrs);
520 	if (IS_ERR(mdev)) {
521 		up_read(&vdpa_dev_lock);
522 		NL_SET_ERR_MSG_MOD(info->extack, "Fail to find the specified mgmt device");
523 		err = PTR_ERR(mdev);
524 		goto out;
525 	}
526 
527 	err = vdpa_mgmtdev_fill(mdev, msg, info->snd_portid, info->snd_seq, 0);
528 	up_read(&vdpa_dev_lock);
529 	if (err)
530 		goto out;
531 	err = genlmsg_reply(msg, info);
532 	return err;
533 
534 out:
535 	nlmsg_free(msg);
536 	return err;
537 }
538 
539 static int
540 vdpa_nl_cmd_mgmtdev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
541 {
542 	struct vdpa_mgmt_dev *mdev;
543 	int start = cb->args[0];
544 	int idx = 0;
545 	int err;
546 
547 	down_read(&vdpa_dev_lock);
548 	list_for_each_entry(mdev, &mdev_head, list) {
549 		if (idx < start) {
550 			idx++;
551 			continue;
552 		}
553 		err = vdpa_mgmtdev_fill(mdev, msg, NETLINK_CB(cb->skb).portid,
554 					cb->nlh->nlmsg_seq, NLM_F_MULTI);
555 		if (err)
556 			goto out;
557 		idx++;
558 	}
559 out:
560 	up_read(&vdpa_dev_lock);
561 	cb->args[0] = idx;
562 	return msg->len;
563 }
564 
565 #define VDPA_DEV_NET_ATTRS_MASK (BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR) | \
566 				 BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU)     | \
567 				 BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP))
568 
569 static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *info)
570 {
571 	struct vdpa_dev_set_config config = {};
572 	struct nlattr **nl_attrs = info->attrs;
573 	struct vdpa_mgmt_dev *mdev;
574 	const u8 *macaddr;
575 	const char *name;
576 	int err = 0;
577 
578 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
579 		return -EINVAL;
580 
581 	name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
582 
583 	if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR]) {
584 		macaddr = nla_data(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR]);
585 		memcpy(config.net.mac, macaddr, sizeof(config.net.mac));
586 		config.mask |= BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR);
587 	}
588 	if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MTU]) {
589 		config.net.mtu =
590 			nla_get_u16(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MTU]);
591 		config.mask |= BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU);
592 	}
593 	if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MAX_VQP]) {
594 		config.net.max_vq_pairs =
595 			nla_get_u16(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MAX_VQP]);
596 		if (!config.net.max_vq_pairs) {
597 			NL_SET_ERR_MSG_MOD(info->extack,
598 					   "At least one pair of VQs is required");
599 			return -EINVAL;
600 		}
601 		config.mask |= BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP);
602 	}
603 
604 	/* Skip checking capability if user didn't prefer to configure any
605 	 * device networking attributes. It is likely that user might have used
606 	 * a device specific method to configure such attributes or using device
607 	 * default attributes.
608 	 */
609 	if ((config.mask & VDPA_DEV_NET_ATTRS_MASK) &&
610 	    !netlink_capable(skb, CAP_NET_ADMIN))
611 		return -EPERM;
612 
613 	down_write(&vdpa_dev_lock);
614 	mdev = vdpa_mgmtdev_get_from_attr(info->attrs);
615 	if (IS_ERR(mdev)) {
616 		NL_SET_ERR_MSG_MOD(info->extack, "Fail to find the specified management device");
617 		err = PTR_ERR(mdev);
618 		goto err;
619 	}
620 	if ((config.mask & mdev->config_attr_mask) != config.mask) {
621 		NL_SET_ERR_MSG_MOD(info->extack,
622 				   "All provided attributes are not supported");
623 		err = -EOPNOTSUPP;
624 		goto err;
625 	}
626 
627 	err = mdev->ops->dev_add(mdev, name, &config);
628 err:
629 	up_write(&vdpa_dev_lock);
630 	return err;
631 }
632 
633 static int vdpa_nl_cmd_dev_del_set_doit(struct sk_buff *skb, struct genl_info *info)
634 {
635 	struct vdpa_mgmt_dev *mdev;
636 	struct vdpa_device *vdev;
637 	struct device *dev;
638 	const char *name;
639 	int err = 0;
640 
641 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
642 		return -EINVAL;
643 	name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
644 
645 	down_write(&vdpa_dev_lock);
646 	dev = bus_find_device(&vdpa_bus, NULL, name, vdpa_name_match);
647 	if (!dev) {
648 		NL_SET_ERR_MSG_MOD(info->extack, "device not found");
649 		err = -ENODEV;
650 		goto dev_err;
651 	}
652 	vdev = container_of(dev, struct vdpa_device, dev);
653 	if (!vdev->mdev) {
654 		NL_SET_ERR_MSG_MOD(info->extack, "Only user created device can be deleted by user");
655 		err = -EINVAL;
656 		goto mdev_err;
657 	}
658 	mdev = vdev->mdev;
659 	mdev->ops->dev_del(mdev, vdev);
660 mdev_err:
661 	put_device(dev);
662 dev_err:
663 	up_write(&vdpa_dev_lock);
664 	return err;
665 }
666 
667 static int
668 vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
669 	      int flags, struct netlink_ext_ack *extack)
670 {
671 	u16 max_vq_size;
672 	u16 min_vq_size = 1;
673 	u32 device_id;
674 	u32 vendor_id;
675 	void *hdr;
676 	int err;
677 
678 	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, VDPA_CMD_DEV_NEW);
679 	if (!hdr)
680 		return -EMSGSIZE;
681 
682 	err = vdpa_nl_mgmtdev_handle_fill(msg, vdev->mdev);
683 	if (err)
684 		goto msg_err;
685 
686 	device_id = vdev->config->get_device_id(vdev);
687 	vendor_id = vdev->config->get_vendor_id(vdev);
688 	max_vq_size = vdev->config->get_vq_num_max(vdev);
689 	if (vdev->config->get_vq_num_min)
690 		min_vq_size = vdev->config->get_vq_num_min(vdev);
691 
692 	err = -EMSGSIZE;
693 	if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev)))
694 		goto msg_err;
695 	if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id))
696 		goto msg_err;
697 	if (nla_put_u32(msg, VDPA_ATTR_DEV_VENDOR_ID, vendor_id))
698 		goto msg_err;
699 	if (nla_put_u32(msg, VDPA_ATTR_DEV_MAX_VQS, vdev->nvqs))
700 		goto msg_err;
701 	if (nla_put_u16(msg, VDPA_ATTR_DEV_MAX_VQ_SIZE, max_vq_size))
702 		goto msg_err;
703 	if (nla_put_u16(msg, VDPA_ATTR_DEV_MIN_VQ_SIZE, min_vq_size))
704 		goto msg_err;
705 
706 	genlmsg_end(msg, hdr);
707 	return 0;
708 
709 msg_err:
710 	genlmsg_cancel(msg, hdr);
711 	return err;
712 }
713 
714 static int vdpa_nl_cmd_dev_get_doit(struct sk_buff *skb, struct genl_info *info)
715 {
716 	struct vdpa_device *vdev;
717 	struct sk_buff *msg;
718 	const char *devname;
719 	struct device *dev;
720 	int err;
721 
722 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
723 		return -EINVAL;
724 	devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
725 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
726 	if (!msg)
727 		return -ENOMEM;
728 
729 	down_read(&vdpa_dev_lock);
730 	dev = bus_find_device(&vdpa_bus, NULL, devname, vdpa_name_match);
731 	if (!dev) {
732 		NL_SET_ERR_MSG_MOD(info->extack, "device not found");
733 		err = -ENODEV;
734 		goto err;
735 	}
736 	vdev = container_of(dev, struct vdpa_device, dev);
737 	if (!vdev->mdev) {
738 		err = -EINVAL;
739 		goto mdev_err;
740 	}
741 	err = vdpa_dev_fill(vdev, msg, info->snd_portid, info->snd_seq, 0, info->extack);
742 	if (err)
743 		goto mdev_err;
744 
745 	err = genlmsg_reply(msg, info);
746 	put_device(dev);
747 	up_read(&vdpa_dev_lock);
748 	return err;
749 
750 mdev_err:
751 	put_device(dev);
752 err:
753 	up_read(&vdpa_dev_lock);
754 	nlmsg_free(msg);
755 	return err;
756 }
757 
758 struct vdpa_dev_dump_info {
759 	struct sk_buff *msg;
760 	struct netlink_callback *cb;
761 	int start_idx;
762 	int idx;
763 };
764 
765 static int vdpa_dev_dump(struct device *dev, void *data)
766 {
767 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
768 	struct vdpa_dev_dump_info *info = data;
769 	int err;
770 
771 	if (!vdev->mdev)
772 		return 0;
773 	if (info->idx < info->start_idx) {
774 		info->idx++;
775 		return 0;
776 	}
777 	err = vdpa_dev_fill(vdev, info->msg, NETLINK_CB(info->cb->skb).portid,
778 			    info->cb->nlh->nlmsg_seq, NLM_F_MULTI, info->cb->extack);
779 	if (err)
780 		return err;
781 
782 	info->idx++;
783 	return 0;
784 }
785 
786 static int vdpa_nl_cmd_dev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
787 {
788 	struct vdpa_dev_dump_info info;
789 
790 	info.msg = msg;
791 	info.cb = cb;
792 	info.start_idx = cb->args[0];
793 	info.idx = 0;
794 
795 	down_read(&vdpa_dev_lock);
796 	bus_for_each_dev(&vdpa_bus, NULL, &info, vdpa_dev_dump);
797 	up_read(&vdpa_dev_lock);
798 	cb->args[0] = info.idx;
799 	return msg->len;
800 }
801 
802 static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev,
803 				       struct sk_buff *msg, u64 features,
804 				       const struct virtio_net_config *config)
805 {
806 	u16 val_u16;
807 
808 	if ((features & BIT_ULL(VIRTIO_NET_F_MQ)) == 0)
809 		return 0;
810 
811 	val_u16 = le16_to_cpu(config->max_virtqueue_pairs);
812 	return nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, val_u16);
813 }
814 
815 static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg)
816 {
817 	struct virtio_net_config config = {};
818 	u64 features;
819 	u16 val_u16;
820 
821 	vdpa_get_config_unlocked(vdev, 0, &config, sizeof(config));
822 
823 	if (nla_put(msg, VDPA_ATTR_DEV_NET_CFG_MACADDR, sizeof(config.mac),
824 		    config.mac))
825 		return -EMSGSIZE;
826 
827 	val_u16 = __virtio16_to_cpu(true, config.status);
828 	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16))
829 		return -EMSGSIZE;
830 
831 	val_u16 = __virtio16_to_cpu(true, config.mtu);
832 	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16))
833 		return -EMSGSIZE;
834 
835 	features = vdev->config->get_driver_features(vdev);
836 	if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features,
837 			      VDPA_ATTR_PAD))
838 		return -EMSGSIZE;
839 
840 	return vdpa_dev_net_mq_config_fill(vdev, msg, features, &config);
841 }
842 
843 static int
844 vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
845 		     int flags, struct netlink_ext_ack *extack)
846 {
847 	u32 device_id;
848 	void *hdr;
849 	int err;
850 
851 	down_read(&vdev->cf_lock);
852 	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags,
853 			  VDPA_CMD_DEV_CONFIG_GET);
854 	if (!hdr) {
855 		err = -EMSGSIZE;
856 		goto out;
857 	}
858 
859 	if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev))) {
860 		err = -EMSGSIZE;
861 		goto msg_err;
862 	}
863 
864 	device_id = vdev->config->get_device_id(vdev);
865 	if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id)) {
866 		err = -EMSGSIZE;
867 		goto msg_err;
868 	}
869 
870 	switch (device_id) {
871 	case VIRTIO_ID_NET:
872 		err = vdpa_dev_net_config_fill(vdev, msg);
873 		break;
874 	default:
875 		err = -EOPNOTSUPP;
876 		break;
877 	}
878 	if (err)
879 		goto msg_err;
880 
881 	up_read(&vdev->cf_lock);
882 	genlmsg_end(msg, hdr);
883 	return 0;
884 
885 msg_err:
886 	genlmsg_cancel(msg, hdr);
887 out:
888 	up_read(&vdev->cf_lock);
889 	return err;
890 }
891 
892 static int vdpa_fill_stats_rec(struct vdpa_device *vdev, struct sk_buff *msg,
893 			       struct genl_info *info, u32 index)
894 {
895 	struct virtio_net_config config = {};
896 	u64 features;
897 	u16 max_vqp;
898 	u8 status;
899 	int err;
900 
901 	status = vdev->config->get_status(vdev);
902 	if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
903 		NL_SET_ERR_MSG_MOD(info->extack, "feature negotiation not complete");
904 		return -EAGAIN;
905 	}
906 	vdpa_get_config_unlocked(vdev, 0, &config, sizeof(config));
907 
908 	max_vqp = __virtio16_to_cpu(true, config.max_virtqueue_pairs);
909 	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, max_vqp))
910 		return -EMSGSIZE;
911 
912 	features = vdev->config->get_driver_features(vdev);
913 	if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES,
914 			      features, VDPA_ATTR_PAD))
915 		return -EMSGSIZE;
916 
917 	if (nla_put_u32(msg, VDPA_ATTR_DEV_QUEUE_INDEX, index))
918 		return -EMSGSIZE;
919 
920 	err = vdev->config->get_vendor_vq_stats(vdev, index, msg, info->extack);
921 	if (err)
922 		return err;
923 
924 	return 0;
925 }
926 
927 static int vendor_stats_fill(struct vdpa_device *vdev, struct sk_buff *msg,
928 			     struct genl_info *info, u32 index)
929 {
930 	int err;
931 
932 	down_read(&vdev->cf_lock);
933 	if (!vdev->config->get_vendor_vq_stats) {
934 		err = -EOPNOTSUPP;
935 		goto out;
936 	}
937 
938 	err = vdpa_fill_stats_rec(vdev, msg, info, index);
939 out:
940 	up_read(&vdev->cf_lock);
941 	return err;
942 }
943 
944 static int vdpa_dev_vendor_stats_fill(struct vdpa_device *vdev,
945 				      struct sk_buff *msg,
946 				      struct genl_info *info, u32 index)
947 {
948 	u32 device_id;
949 	void *hdr;
950 	int err;
951 	u32 portid = info->snd_portid;
952 	u32 seq = info->snd_seq;
953 	u32 flags = 0;
954 
955 	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags,
956 			  VDPA_CMD_DEV_VSTATS_GET);
957 	if (!hdr)
958 		return -EMSGSIZE;
959 
960 	if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev))) {
961 		err = -EMSGSIZE;
962 		goto undo_msg;
963 	}
964 
965 	device_id = vdev->config->get_device_id(vdev);
966 	if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id)) {
967 		err = -EMSGSIZE;
968 		goto undo_msg;
969 	}
970 
971 	switch (device_id) {
972 	case VIRTIO_ID_NET:
973 		if (index > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX) {
974 			NL_SET_ERR_MSG_MOD(info->extack, "queue index excceeds max value");
975 			err = -ERANGE;
976 			break;
977 		}
978 
979 		err = vendor_stats_fill(vdev, msg, info, index);
980 		break;
981 	default:
982 		err = -EOPNOTSUPP;
983 		break;
984 	}
985 	genlmsg_end(msg, hdr);
986 
987 	return err;
988 
989 undo_msg:
990 	genlmsg_cancel(msg, hdr);
991 	return err;
992 }
993 
994 static int vdpa_nl_cmd_dev_config_get_doit(struct sk_buff *skb, struct genl_info *info)
995 {
996 	struct vdpa_device *vdev;
997 	struct sk_buff *msg;
998 	const char *devname;
999 	struct device *dev;
1000 	int err;
1001 
1002 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
1003 		return -EINVAL;
1004 	devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
1005 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1006 	if (!msg)
1007 		return -ENOMEM;
1008 
1009 	down_read(&vdpa_dev_lock);
1010 	dev = bus_find_device(&vdpa_bus, NULL, devname, vdpa_name_match);
1011 	if (!dev) {
1012 		NL_SET_ERR_MSG_MOD(info->extack, "device not found");
1013 		err = -ENODEV;
1014 		goto dev_err;
1015 	}
1016 	vdev = container_of(dev, struct vdpa_device, dev);
1017 	if (!vdev->mdev) {
1018 		NL_SET_ERR_MSG_MOD(info->extack, "unmanaged vdpa device");
1019 		err = -EINVAL;
1020 		goto mdev_err;
1021 	}
1022 	err = vdpa_dev_config_fill(vdev, msg, info->snd_portid, info->snd_seq,
1023 				   0, info->extack);
1024 	if (!err)
1025 		err = genlmsg_reply(msg, info);
1026 
1027 mdev_err:
1028 	put_device(dev);
1029 dev_err:
1030 	up_read(&vdpa_dev_lock);
1031 	if (err)
1032 		nlmsg_free(msg);
1033 	return err;
1034 }
1035 
1036 static int vdpa_dev_config_dump(struct device *dev, void *data)
1037 {
1038 	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
1039 	struct vdpa_dev_dump_info *info = data;
1040 	int err;
1041 
1042 	if (!vdev->mdev)
1043 		return 0;
1044 	if (info->idx < info->start_idx) {
1045 		info->idx++;
1046 		return 0;
1047 	}
1048 	err = vdpa_dev_config_fill(vdev, info->msg, NETLINK_CB(info->cb->skb).portid,
1049 				   info->cb->nlh->nlmsg_seq, NLM_F_MULTI,
1050 				   info->cb->extack);
1051 	if (err)
1052 		return err;
1053 
1054 	info->idx++;
1055 	return 0;
1056 }
1057 
1058 static int
1059 vdpa_nl_cmd_dev_config_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
1060 {
1061 	struct vdpa_dev_dump_info info;
1062 
1063 	info.msg = msg;
1064 	info.cb = cb;
1065 	info.start_idx = cb->args[0];
1066 	info.idx = 0;
1067 
1068 	down_read(&vdpa_dev_lock);
1069 	bus_for_each_dev(&vdpa_bus, NULL, &info, vdpa_dev_config_dump);
1070 	up_read(&vdpa_dev_lock);
1071 	cb->args[0] = info.idx;
1072 	return msg->len;
1073 }
1074 
1075 static int vdpa_nl_cmd_dev_stats_get_doit(struct sk_buff *skb,
1076 					  struct genl_info *info)
1077 {
1078 	struct vdpa_device *vdev;
1079 	struct sk_buff *msg;
1080 	const char *devname;
1081 	struct device *dev;
1082 	u32 index;
1083 	int err;
1084 
1085 	if (!info->attrs[VDPA_ATTR_DEV_NAME])
1086 		return -EINVAL;
1087 
1088 	if (!info->attrs[VDPA_ATTR_DEV_QUEUE_INDEX])
1089 		return -EINVAL;
1090 
1091 	devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
1092 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1093 	if (!msg)
1094 		return -ENOMEM;
1095 
1096 	index = nla_get_u32(info->attrs[VDPA_ATTR_DEV_QUEUE_INDEX]);
1097 	down_read(&vdpa_dev_lock);
1098 	dev = bus_find_device(&vdpa_bus, NULL, devname, vdpa_name_match);
1099 	if (!dev) {
1100 		NL_SET_ERR_MSG_MOD(info->extack, "device not found");
1101 		err = -ENODEV;
1102 		goto dev_err;
1103 	}
1104 	vdev = container_of(dev, struct vdpa_device, dev);
1105 	if (!vdev->mdev) {
1106 		NL_SET_ERR_MSG_MOD(info->extack, "unmanaged vdpa device");
1107 		err = -EINVAL;
1108 		goto mdev_err;
1109 	}
1110 	err = vdpa_dev_vendor_stats_fill(vdev, msg, info, index);
1111 	if (err)
1112 		goto mdev_err;
1113 
1114 	err = genlmsg_reply(msg, info);
1115 
1116 	put_device(dev);
1117 	up_read(&vdpa_dev_lock);
1118 
1119 	return err;
1120 
1121 mdev_err:
1122 	put_device(dev);
1123 dev_err:
1124 	nlmsg_free(msg);
1125 	up_read(&vdpa_dev_lock);
1126 	return err;
1127 }
1128 
1129 static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = {
1130 	[VDPA_ATTR_MGMTDEV_BUS_NAME] = { .type = NLA_NUL_STRING },
1131 	[VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING },
1132 	[VDPA_ATTR_DEV_NAME] = { .type = NLA_STRING },
1133 	[VDPA_ATTR_DEV_NET_CFG_MACADDR] = NLA_POLICY_ETH_ADDR,
1134 	/* virtio spec 1.1 section 5.1.4.1 for valid MTU range */
1135 	[VDPA_ATTR_DEV_NET_CFG_MTU] = NLA_POLICY_MIN(NLA_U16, 68),
1136 };
1137 
1138 static const struct genl_ops vdpa_nl_ops[] = {
1139 	{
1140 		.cmd = VDPA_CMD_MGMTDEV_GET,
1141 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1142 		.doit = vdpa_nl_cmd_mgmtdev_get_doit,
1143 		.dumpit = vdpa_nl_cmd_mgmtdev_get_dumpit,
1144 	},
1145 	{
1146 		.cmd = VDPA_CMD_DEV_NEW,
1147 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1148 		.doit = vdpa_nl_cmd_dev_add_set_doit,
1149 		.flags = GENL_ADMIN_PERM,
1150 	},
1151 	{
1152 		.cmd = VDPA_CMD_DEV_DEL,
1153 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1154 		.doit = vdpa_nl_cmd_dev_del_set_doit,
1155 		.flags = GENL_ADMIN_PERM,
1156 	},
1157 	{
1158 		.cmd = VDPA_CMD_DEV_GET,
1159 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1160 		.doit = vdpa_nl_cmd_dev_get_doit,
1161 		.dumpit = vdpa_nl_cmd_dev_get_dumpit,
1162 	},
1163 	{
1164 		.cmd = VDPA_CMD_DEV_CONFIG_GET,
1165 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1166 		.doit = vdpa_nl_cmd_dev_config_get_doit,
1167 		.dumpit = vdpa_nl_cmd_dev_config_get_dumpit,
1168 	},
1169 	{
1170 		.cmd = VDPA_CMD_DEV_VSTATS_GET,
1171 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1172 		.doit = vdpa_nl_cmd_dev_stats_get_doit,
1173 		.flags = GENL_ADMIN_PERM,
1174 	},
1175 };
1176 
1177 static struct genl_family vdpa_nl_family __ro_after_init = {
1178 	.name = VDPA_GENL_NAME,
1179 	.version = VDPA_GENL_VERSION,
1180 	.maxattr = VDPA_ATTR_MAX,
1181 	.policy = vdpa_nl_policy,
1182 	.netnsok = false,
1183 	.module = THIS_MODULE,
1184 	.ops = vdpa_nl_ops,
1185 	.n_ops = ARRAY_SIZE(vdpa_nl_ops),
1186 	.resv_start_op = VDPA_CMD_DEV_VSTATS_GET + 1,
1187 };
1188 
1189 static int vdpa_init(void)
1190 {
1191 	int err;
1192 
1193 	err = bus_register(&vdpa_bus);
1194 	if (err)
1195 		return err;
1196 	err = genl_register_family(&vdpa_nl_family);
1197 	if (err)
1198 		goto err;
1199 	return 0;
1200 
1201 err:
1202 	bus_unregister(&vdpa_bus);
1203 	return err;
1204 }
1205 
1206 static void __exit vdpa_exit(void)
1207 {
1208 	genl_unregister_family(&vdpa_nl_family);
1209 	bus_unregister(&vdpa_bus);
1210 	ida_destroy(&vdpa_index_ida);
1211 }
1212 core_initcall(vdpa_init);
1213 module_exit(vdpa_exit);
1214 
1215 MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
1216 MODULE_LICENSE("GPL v2");
1217