xref: /linux/include/linux/vdpa.h (revision bf897d2626abe4559953342e2f7dda05d034c8c7)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_VDPA_H
3 #define _LINUX_VDPA_H
4 
5 #include <linux/kernel.h>
6 #include <linux/device.h>
7 #include <linux/interrupt.h>
8 #include <linux/virtio.h>
9 #include <linux/vhost_iotlb.h>
10 #include <linux/virtio_net.h>
11 #include <linux/virtio_blk.h>
12 #include <linux/if_ether.h>
13 
14 /**
15  * struct vdpa_callback - vDPA callback definition.
16  * @callback: interrupt callback function
17  * @private: the data passed to the callback function
18  * @trigger: the eventfd for the callback (Optional).
19  *           When it is set, the vDPA driver must guarantee that
20  *           signaling it is functional equivalent to triggering
21  *           the callback. Then vDPA parent can signal it directly
22  *           instead of triggering the callback.
23  */
24 struct vdpa_callback {
25 	irqreturn_t (*callback)(void *data);
26 	void *private;
27 	struct eventfd_ctx *trigger;
28 };
29 
30 /**
31  * struct vdpa_notification_area - vDPA notification area
32  * @addr: base address of the notification area
33  * @size: size of the notification area
34  */
35 struct vdpa_notification_area {
36 	resource_size_t addr;
37 	resource_size_t size;
38 };
39 
40 /**
41  * struct vdpa_vq_state_split - vDPA split virtqueue state
42  * @avail_index: available index
43  */
44 struct vdpa_vq_state_split {
45 	u16	avail_index;
46 };
47 
48 /**
49  * struct vdpa_vq_state_packed - vDPA packed virtqueue state
50  * @last_avail_counter: last driver ring wrap counter observed by device
51  * @last_avail_idx: device available index
52  * @last_used_counter: device ring wrap counter
53  * @last_used_idx: used index
54  */
55 struct vdpa_vq_state_packed {
56 	u16	last_avail_counter:1;
57 	u16	last_avail_idx:15;
58 	u16	last_used_counter:1;
59 	u16	last_used_idx:15;
60 };
61 
62 struct vdpa_vq_state {
63 	union {
64 		struct vdpa_vq_state_split split;
65 		struct vdpa_vq_state_packed packed;
66 	};
67 };
68 
69 struct vdpa_mgmt_dev;
70 
71 /**
72  * struct vdpa_device - representation of a vDPA device
73  * @dev: underlying device
74  * @vmap: the metadata passed to upper layer to be used for mapping
75  * @driver_override: driver name to force a match; do not set directly,
76  *                   because core frees it; use driver_set_override() to
77  *                   set or clear it.
78  * @config: the configuration ops for this device.
79  * @map: the map ops for this device
80  * @cf_lock: Protects get and set access to configuration layout.
81  * @index: device index
82  * @features_valid: were features initialized? for legacy guests
83  * @ngroups: the number of virtqueue groups
84  * @nas: the number of address spaces
85  * @use_va: indicate whether virtual address must be used by this device
86  * @nvqs: maximum number of supported virtqueues
87  * @mdev: management device pointer; caller must setup when registering device as part
88  *	  of dev_add() mgmtdev ops callback before invoking _vdpa_register_device().
89  */
90 struct vdpa_device {
91 	struct device dev;
92 	union virtio_map vmap;
93 	const char *driver_override;
94 	const struct vdpa_config_ops *config;
95 	const struct virtio_map_ops *map;
96 	struct rw_semaphore cf_lock; /* Protects get/set config */
97 	unsigned int index;
98 	bool features_valid;
99 	bool use_va;
100 	u32 nvqs;
101 	struct vdpa_mgmt_dev *mdev;
102 	unsigned int ngroups;
103 	unsigned int nas;
104 };
105 
106 /**
107  * struct vdpa_iova_range - the IOVA range support by the device
108  * @first: start of the IOVA range
109  * @last: end of the IOVA range
110  */
111 struct vdpa_iova_range {
112 	u64 first;
113 	u64 last;
114 };
115 
116 struct vdpa_dev_set_config {
117 	u64 device_features;
118 	struct {
119 		u8 mac[ETH_ALEN];
120 		u16 mtu;
121 		u16 max_vq_pairs;
122 	} net;
123 	u64 mask;
124 };
125 
126 /**
127  * struct vdpa_map_file - file area for device memory mapping
128  * @file: vma->vm_file for the mapping
129  * @offset: mapping offset in the vm_file
130  */
131 struct vdpa_map_file {
132 	struct file *file;
133 	u64 offset;
134 };
135 
136 /**
137  * struct vdpa_config_ops - operations for configuring a vDPA device.
138  * Note: vDPA device drivers are required to implement all of the
139  * operations unless it is mentioned to be optional in the following
140  * list.
141  *
142  * @set_vq_address:		Set the address of virtqueue
143  *				@vdev: vdpa device
144  *				@idx: virtqueue index
145  *				@desc_area: address of desc area
146  *				@driver_area: address of driver area
147  *				@device_area: address of device area
148  *				Returns integer: success (0) or error (< 0)
149  * @set_vq_num:			Set the size of virtqueue
150  *				@vdev: vdpa device
151  *				@idx: virtqueue index
152  *				@num: the size of virtqueue
153  * @kick_vq:			Kick the virtqueue
154  *				@vdev: vdpa device
155  *				@idx: virtqueue index
156  * @kick_vq_with_data:		Kick the virtqueue and supply extra data
157  *				(only if VIRTIO_F_NOTIFICATION_DATA is negotiated)
158  *				@vdev: vdpa device
159  *				@data for split virtqueue:
160  *				16 bits vqn and 16 bits next available index.
161  *				@data for packed virtqueue:
162  *				16 bits vqn, 15 least significant bits of
163  *				next available index and 1 bit next_wrap.
164  * @set_vq_cb:			Set the interrupt callback function for
165  *				a virtqueue
166  *				@vdev: vdpa device
167  *				@idx: virtqueue index
168  *				@cb: virtio-vdev interrupt callback structure
169  * @set_vq_ready:		Set ready status for a virtqueue
170  *				@vdev: vdpa device
171  *				@idx: virtqueue index
172  *				@ready: ready (true) not ready(false)
173  * @get_vq_ready:		Get ready status for a virtqueue
174  *				@vdev: vdpa device
175  *				@idx: virtqueue index
176  *				Returns boolean: ready (true) or not (false)
177  * @set_vq_state:		Set the state for a virtqueue
178  *				@vdev: vdpa device
179  *				@idx: virtqueue index
180  *				@state: pointer to set virtqueue state (last_avail_idx)
181  *				Returns integer: success (0) or error (< 0)
182  * @get_vq_state:		Get the state for a virtqueue
183  *				@vdev: vdpa device
184  *				@idx: virtqueue index
185  *				@state: pointer to returned state (last_avail_idx)
186  * @get_vendor_vq_stats:	Get the vendor statistics of a device.
187  *				@vdev: vdpa device
188  *				@idx: virtqueue index
189  *				@msg: socket buffer holding stats message
190  *				@extack: extack for reporting error messages
191  *				Returns integer: success (0) or error (< 0)
192  * @get_vq_notification:	Get the notification area for a virtqueue (optional)
193  *				@vdev: vdpa device
194  *				@idx: virtqueue index
195  *				Returns the notification area
196  * @get_vq_irq:			Get the irq number of a virtqueue (optional,
197  *				but must implemented if require vq irq offloading)
198  *				@vdev: vdpa device
199  *				@idx: virtqueue index
200  *				Returns int: irq number of a virtqueue,
201  *				negative number if no irq assigned.
202  * @get_vq_size:		Get the size of a specific virtqueue (optional)
203  *				@vdev: vdpa device
204  *				@idx: virtqueue index
205  *				Return u16: the size of the virtqueue
206  * @get_vq_align:		Get the virtqueue align requirement
207  *				for the device
208  *				@vdev: vdpa device
209  *				Returns virtqueue algin requirement
210  * @get_vq_group:		Get the group id for a specific
211  *				virtqueue (optional)
212  *				@vdev: vdpa device
213  *				@idx: virtqueue index
214  *				Returns u32: group id for this virtqueue
215  * @get_vq_desc_group:		Get the group id for the descriptor table of
216  *				a specific virtqueue (optional)
217  *				@vdev: vdpa device
218  *				@idx: virtqueue index
219  *				Returns u32: group id for the descriptor table
220  *				portion of this virtqueue. Could be different
221  *				than the one from @get_vq_group, in which case
222  *				the access to the descriptor table can be
223  *				confined to a separate asid, isolating from
224  *				the virtqueue's buffer address access.
225  * @get_device_features:	Get virtio features supported by the device
226  *				@vdev: vdpa device
227  *				Returns the virtio features support by the
228  *				device
229  * @get_backend_features:	Get parent-specific backend features (optional)
230  *				Returns the vdpa features supported by the
231  *				device.
232  * @set_driver_features:	Set virtio features supported by the driver
233  *				@vdev: vdpa device
234  *				@features: feature support by the driver
235  *				Returns integer: success (0) or error (< 0)
236  * @get_driver_features:	Get the virtio driver features in action
237  *				@vdev: vdpa device
238  *				Returns the virtio features accepted
239  * @set_config_cb:		Set the config interrupt callback
240  *				@vdev: vdpa device
241  *				@cb: virtio-vdev interrupt callback structure
242  * @get_vq_num_max:		Get the max size of virtqueue
243  *				@vdev: vdpa device
244  *				Returns u16: max size of virtqueue
245  * @get_vq_num_min:		Get the min size of virtqueue (optional)
246  *				@vdev: vdpa device
247  *				Returns u16: min size of virtqueue
248  * @get_device_id:		Get virtio device id
249  *				@vdev: vdpa device
250  *				Returns u32: virtio device id
251  * @get_vendor_id:		Get id for the vendor that provides this device
252  *				@vdev: vdpa device
253  *				Returns u32: virtio vendor id
254  * @get_status:			Get the device status
255  *				@vdev: vdpa device
256  *				Returns u8: virtio device status
257  * @set_status:			Set the device status
258  *				@vdev: vdpa device
259  *				@status: virtio device status
260  * @reset:			Reset device
261  *				@vdev: vdpa device
262  *				Returns integer: success (0) or error (< 0)
263  * @compat_reset:		Reset device with compatibility quirks to
264  *				accommodate older userspace. Only needed by
265  *				parent driver which used to have bogus reset
266  *				behaviour, and has to maintain such behaviour
267  *				for compatibility with older userspace.
268  *				Historically compliant driver only has to
269  *				implement .reset, Historically non-compliant
270  *				driver should implement both.
271  *				@vdev: vdpa device
272  *				@flags: compatibility quirks for reset
273  *				Returns integer: success (0) or error (< 0)
274  * @suspend:			Suspend the device (optional)
275  *				@vdev: vdpa device
276  *				Returns integer: success (0) or error (< 0)
277  * @resume:			Resume the device (optional)
278  *				@vdev: vdpa device
279  *				Returns integer: success (0) or error (< 0)
280  * @get_config_size:		Get the size of the configuration space includes
281  *				fields that are conditional on feature bits.
282  *				@vdev: vdpa device
283  *				Returns size_t: configuration size
284  * @get_config:			Read from device specific configuration space
285  *				@vdev: vdpa device
286  *				@offset: offset from the beginning of
287  *				configuration space
288  *				@buf: buffer used to read to
289  *				@len: the length to read from
290  *				configuration space
291  * @set_config:			Write to device specific configuration space
292  *				@vdev: vdpa device
293  *				@offset: offset from the beginning of
294  *				configuration space
295  *				@buf: buffer used to write from
296  *				@len: the length to write to
297  *				configuration space
298  * @get_generation:		Get device config generation (optional)
299  *				@vdev: vdpa device
300  *				Returns u32: device generation
301  * @get_iova_range:		Get supported iova range (optional)
302  *				@vdev: vdpa device
303  *				Returns the iova range supported by
304  *				the device.
305  * @set_vq_affinity:		Set the affinity of virtqueue (optional)
306  *				@vdev: vdpa device
307  *				@idx: virtqueue index
308  *				@cpu_mask: the affinity mask
309  *				Returns integer: success (0) or error (< 0)
310  * @get_vq_affinity:		Get the affinity of virtqueue (optional)
311  *				@vdev: vdpa device
312  *				@idx: virtqueue index
313  *				Returns the affinity mask
314  * @set_group_asid:		Set address space identifier for a
315  *				virtqueue group (optional)
316  *				@vdev: vdpa device
317  *				@group: virtqueue group
318  *				@asid: address space id for this group
319  *				Returns integer: success (0) or error (< 0)
320  * @set_map:			Set device memory mapping (optional)
321  *				Needed for device that using device
322  *				specific DMA translation (on-chip IOMMU)
323  *				@vdev: vdpa device
324  *				@asid: address space identifier
325  *				@iotlb: vhost memory mapping to be
326  *				used by the vDPA
327  *				Returns integer: success (0) or error (< 0)
328  * @dma_map:			Map an area of PA to IOVA (optional)
329  *				Needed for device that using device
330  *				specific DMA translation (on-chip IOMMU)
331  *				and preferring incremental map.
332  *				@vdev: vdpa device
333  *				@asid: address space identifier
334  *				@iova: iova to be mapped
335  *				@size: size of the area
336  *				@pa: physical address for the map
337  *				@perm: device access permission (VHOST_MAP_XX)
338  *				Returns integer: success (0) or error (< 0)
339  * @dma_unmap:			Unmap an area of IOVA (optional but
340  *				must be implemented with dma_map)
341  *				Needed for device that using device
342  *				specific DMA translation (on-chip IOMMU)
343  *				and preferring incremental unmap.
344  *				@vdev: vdpa device
345  *				@asid: address space identifier
346  *				@iova: iova to be unmapped
347  *				@size: size of the area
348  *				Returns integer: success (0) or error (< 0)
349  * @reset_map:			Reset device memory mapping to the default
350  *				state (optional)
351  *				Needed for devices that are using device
352  *				specific DMA translation and prefer mapping
353  *				to be decoupled from the virtio life cycle,
354  *				i.e. device .reset op does not reset mapping
355  *				@vdev: vdpa device
356  *				@asid: address space identifier
357  *				Returns integer: success (0) or error (< 0)
358  * @get_vq_map:		Get the map metadata for a specific
359  *				virtqueue (optional)
360  *				@vdev: vdpa device
361  *				@idx: virtqueue index
362  *				Returns map token union error (NULL)
363  * @bind_mm:			Bind the device to a specific address space
364  *				so the vDPA framework can use VA when this
365  *				callback is implemented. (optional)
366  *				@vdev: vdpa device
367  *				@mm: address space to bind
368  * @unbind_mm:			Unbind the device from the address space
369  *				bound using the bind_mm callback. (optional)
370  *				@vdev: vdpa device
371  * @free:			Free resources that belongs to vDPA (optional)
372  *				@vdev: vdpa device
373  */
374 struct vdpa_config_ops {
375 	/* Virtqueue ops */
376 	int (*set_vq_address)(struct vdpa_device *vdev,
377 			      u16 idx, u64 desc_area, u64 driver_area,
378 			      u64 device_area);
379 	void (*set_vq_num)(struct vdpa_device *vdev, u16 idx, u32 num);
380 	void (*kick_vq)(struct vdpa_device *vdev, u16 idx);
381 	void (*kick_vq_with_data)(struct vdpa_device *vdev, u32 data);
382 	void (*set_vq_cb)(struct vdpa_device *vdev, u16 idx,
383 			  struct vdpa_callback *cb);
384 	void (*set_vq_ready)(struct vdpa_device *vdev, u16 idx, bool ready);
385 	bool (*get_vq_ready)(struct vdpa_device *vdev, u16 idx);
386 	int (*set_vq_state)(struct vdpa_device *vdev, u16 idx,
387 			    const struct vdpa_vq_state *state);
388 	int (*get_vq_state)(struct vdpa_device *vdev, u16 idx,
389 			    struct vdpa_vq_state *state);
390 	int (*get_vendor_vq_stats)(struct vdpa_device *vdev, u16 idx,
391 				   struct sk_buff *msg,
392 				   struct netlink_ext_ack *extack);
393 	struct vdpa_notification_area
394 	(*get_vq_notification)(struct vdpa_device *vdev, u16 idx);
395 	/* vq irq is not expected to be changed once DRIVER_OK is set */
396 	int (*get_vq_irq)(struct vdpa_device *vdev, u16 idx);
397 	u16 (*get_vq_size)(struct vdpa_device *vdev, u16 idx);
398 
399 	/* Device ops */
400 	u32 (*get_vq_align)(struct vdpa_device *vdev);
401 	u32 (*get_vq_group)(struct vdpa_device *vdev, u16 idx);
402 	u32 (*get_vq_desc_group)(struct vdpa_device *vdev, u16 idx);
403 	u64 (*get_device_features)(struct vdpa_device *vdev);
404 	u64 (*get_backend_features)(const struct vdpa_device *vdev);
405 	int (*set_driver_features)(struct vdpa_device *vdev, u64 features);
406 	u64 (*get_driver_features)(struct vdpa_device *vdev);
407 	void (*set_config_cb)(struct vdpa_device *vdev,
408 			      struct vdpa_callback *cb);
409 	u16 (*get_vq_num_max)(struct vdpa_device *vdev);
410 	u16 (*get_vq_num_min)(struct vdpa_device *vdev);
411 	u32 (*get_device_id)(struct vdpa_device *vdev);
412 	u32 (*get_vendor_id)(struct vdpa_device *vdev);
413 	u8 (*get_status)(struct vdpa_device *vdev);
414 	void (*set_status)(struct vdpa_device *vdev, u8 status);
415 	int (*reset)(struct vdpa_device *vdev);
416 	int (*compat_reset)(struct vdpa_device *vdev, u32 flags);
417 #define VDPA_RESET_F_CLEAN_MAP 1
418 	int (*suspend)(struct vdpa_device *vdev);
419 	int (*resume)(struct vdpa_device *vdev);
420 	size_t (*get_config_size)(struct vdpa_device *vdev);
421 	void (*get_config)(struct vdpa_device *vdev, unsigned int offset,
422 			   void *buf, unsigned int len);
423 	void (*set_config)(struct vdpa_device *vdev, unsigned int offset,
424 			   const void *buf, unsigned int len);
425 	u32 (*get_generation)(struct vdpa_device *vdev);
426 	struct vdpa_iova_range (*get_iova_range)(struct vdpa_device *vdev);
427 	int (*set_vq_affinity)(struct vdpa_device *vdev, u16 idx,
428 			       const struct cpumask *cpu_mask);
429 	const struct cpumask *(*get_vq_affinity)(struct vdpa_device *vdev,
430 						 u16 idx);
431 
432 	/* DMA ops */
433 	int (*set_map)(struct vdpa_device *vdev, unsigned int asid,
434 		       struct vhost_iotlb *iotlb);
435 	int (*dma_map)(struct vdpa_device *vdev, unsigned int asid,
436 		       u64 iova, u64 size, u64 pa, u32 perm, void *opaque);
437 	int (*dma_unmap)(struct vdpa_device *vdev, unsigned int asid,
438 			 u64 iova, u64 size);
439 	int (*reset_map)(struct vdpa_device *vdev, unsigned int asid);
440 	int (*set_group_asid)(struct vdpa_device *vdev, unsigned int group,
441 			      unsigned int asid);
442 	union virtio_map (*get_vq_map)(struct vdpa_device *vdev, u16 idx);
443 	int (*bind_mm)(struct vdpa_device *vdev, struct mm_struct *mm);
444 	void (*unbind_mm)(struct vdpa_device *vdev);
445 
446 	/* Free device resources */
447 	void (*free)(struct vdpa_device *vdev);
448 };
449 
450 struct vdpa_device *__vdpa_alloc_device(struct device *parent,
451 					const struct vdpa_config_ops *config,
452 					const struct virtio_map_ops *map,
453 					unsigned int ngroups, unsigned int nas,
454 					size_t size, const char *name,
455 					bool use_va);
456 
457 /**
458  * vdpa_alloc_device - allocate and initilaize a vDPA device
459  *
460  * @dev_struct: the type of the parent structure
461  * @member: the name of struct vdpa_device within the @dev_struct
462  * @parent: the parent device
463  * @config: the bus operations that is supported by this device
464  * @map: the map operations that is supported by this device
465  * @ngroups: the number of virtqueue groups supported by this device
466  * @nas: the number of address spaces
467  * @name: name of the vdpa device
468  * @use_va: indicate whether virtual address must be used by this device
469  *
470  * Return allocated data structure or ERR_PTR upon error
471  */
472 #define vdpa_alloc_device(dev_struct, member, parent, config, map, \
473 			  ngroups, nas, name, use_va)		   \
474 			  container_of((__vdpa_alloc_device( \
475 				       parent, config, map, ngroups, nas, \
476 				       (sizeof(dev_struct) + \
477 				       BUILD_BUG_ON_ZERO(offsetof( \
478 				       dev_struct, member))), name, use_va)), \
479 				       dev_struct, member)
480 
481 int vdpa_register_device(struct vdpa_device *vdev, u32 nvqs);
482 void vdpa_unregister_device(struct vdpa_device *vdev);
483 
484 int _vdpa_register_device(struct vdpa_device *vdev, u32 nvqs);
485 void _vdpa_unregister_device(struct vdpa_device *vdev);
486 
487 /**
488  * struct vdpa_driver - operations for a vDPA driver
489  * @driver: underlying device driver
490  * @probe: the function to call when a device is found.  Returns 0 or -errno.
491  * @remove: the function to call when a device is removed.
492  */
493 struct vdpa_driver {
494 	struct device_driver driver;
495 	int (*probe)(struct vdpa_device *vdev);
496 	void (*remove)(struct vdpa_device *vdev);
497 };
498 
499 #define vdpa_register_driver(drv) \
500 	__vdpa_register_driver(drv, THIS_MODULE)
501 int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner);
502 void vdpa_unregister_driver(struct vdpa_driver *drv);
503 
504 #define module_vdpa_driver(__vdpa_driver) \
505 	module_driver(__vdpa_driver, vdpa_register_driver,	\
506 		      vdpa_unregister_driver)
507 
508 static inline struct vdpa_driver *drv_to_vdpa(struct device_driver *driver)
509 {
510 	return container_of(driver, struct vdpa_driver, driver);
511 }
512 
513 static inline struct vdpa_device *dev_to_vdpa(struct device *_dev)
514 {
515 	return container_of(_dev, struct vdpa_device, dev);
516 }
517 
518 static inline void *vdpa_get_drvdata(const struct vdpa_device *vdev)
519 {
520 	return dev_get_drvdata(&vdev->dev);
521 }
522 
523 static inline void vdpa_set_drvdata(struct vdpa_device *vdev, void *data)
524 {
525 	dev_set_drvdata(&vdev->dev, data);
526 }
527 
528 static inline union virtio_map vdpa_get_map(struct vdpa_device *vdev)
529 {
530 	return vdev->vmap;
531 }
532 
533 static inline int vdpa_reset(struct vdpa_device *vdev, u32 flags)
534 {
535 	const struct vdpa_config_ops *ops = vdev->config;
536 	int ret;
537 
538 	down_write(&vdev->cf_lock);
539 	vdev->features_valid = false;
540 	if (ops->compat_reset && flags)
541 		ret = ops->compat_reset(vdev, flags);
542 	else
543 		ret = ops->reset(vdev);
544 	up_write(&vdev->cf_lock);
545 	return ret;
546 }
547 
548 static inline int vdpa_set_features_unlocked(struct vdpa_device *vdev, u64 features)
549 {
550 	const struct vdpa_config_ops *ops = vdev->config;
551 	int ret;
552 
553 	vdev->features_valid = true;
554 	ret = ops->set_driver_features(vdev, features);
555 
556 	return ret;
557 }
558 
559 static inline int vdpa_set_features(struct vdpa_device *vdev, u64 features)
560 {
561 	int ret;
562 
563 	down_write(&vdev->cf_lock);
564 	ret = vdpa_set_features_unlocked(vdev, features);
565 	up_write(&vdev->cf_lock);
566 
567 	return ret;
568 }
569 
570 void vdpa_get_config(struct vdpa_device *vdev, unsigned int offset,
571 		     void *buf, unsigned int len);
572 void vdpa_set_config(struct vdpa_device *dev, unsigned int offset,
573 		     const void *buf, unsigned int length);
574 void vdpa_set_status(struct vdpa_device *vdev, u8 status);
575 
576 /**
577  * struct vdpa_mgmtdev_ops - vdpa device ops
578  * @dev_add: Add a vdpa device using alloc and register
579  *	     @mdev: parent device to use for device addition
580  *	     @name: name of the new vdpa device
581  *	     @config: config attributes to apply to the device under creation
582  *	     Driver need to add a new device using _vdpa_register_device()
583  *	     after fully initializing the vdpa device. Driver must return 0
584  *	     on success or appropriate error code.
585  * @dev_del: Remove a vdpa device using unregister
586  *	     @mdev: parent device to use for device removal
587  *	     @dev: vdpa device to remove
588  *	     Driver need to remove the specified device by calling
589  *	     _vdpa_unregister_device().
590  * @dev_set_attr: change a vdpa device's attr after it was create
591  *	     @mdev: parent device to use for device
592  *	     @dev: vdpa device structure
593  *	     @config:Attributes to be set for the device.
594  *	     The driver needs to check the mask of the structure and then set
595  *	     the related information to the vdpa device. The driver must return 0
596  *	     if set successfully.
597  */
598 struct vdpa_mgmtdev_ops {
599 	int (*dev_add)(struct vdpa_mgmt_dev *mdev, const char *name,
600 		       const struct vdpa_dev_set_config *config);
601 	void (*dev_del)(struct vdpa_mgmt_dev *mdev, struct vdpa_device *dev);
602 	int (*dev_set_attr)(struct vdpa_mgmt_dev *mdev, struct vdpa_device *dev,
603 			    const struct vdpa_dev_set_config *config);
604 };
605 
606 /**
607  * struct vdpa_mgmt_dev - vdpa management device
608  * @device: Management parent device
609  * @ops: operations supported by management device
610  * @id_table: Pointer to device id table of supported ids
611  * @config_attr_mask: bit mask of attributes of type enum vdpa_attr that
612  *		      management device support during dev_add callback
613  * @list: list entry
614  * @supported_features: features supported by device
615  * @max_supported_vqs: maximum number of virtqueues supported by device
616  */
617 struct vdpa_mgmt_dev {
618 	struct device *device;
619 	const struct vdpa_mgmtdev_ops *ops;
620 	struct virtio_device_id *id_table;
621 	u64 config_attr_mask;
622 	struct list_head list;
623 	u64 supported_features;
624 	u32 max_supported_vqs;
625 };
626 
627 int vdpa_mgmtdev_register(struct vdpa_mgmt_dev *mdev);
628 void vdpa_mgmtdev_unregister(struct vdpa_mgmt_dev *mdev);
629 
630 #endif /* _LINUX_VDPA_H */
631