[linux-2.6-block.git] / include / linux / vdpa.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_VDPA_H
#define _LINUX_VDPA_H

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/vhost_iotlb.h>

/**
 * vDPA callback definition.
 * @callback: interrupt callback function
 * @private: the data passed to the callback function
 */
struct vdpa_callback {
	irqreturn_t (*callback)(void *data);
	void *private;
};

/**
 * vDPA notification area
 * @addr: base address of the notification area
 * @size: size of the notification area
 */
struct vdpa_notification_area {
	resource_size_t addr;
	resource_size_t size;
};

/**
 * vDPA vq_state definition
 * @avail_index: available index
 */
struct vdpa_vq_state {
	u16	avail_index;
};

/**
 * vDPA device - representation of a vDPA device
 * @dev: underlying device
 * @dma_dev: the actual device that is performing DMA
 * @config: the configuration ops for this device.
 * @index: device index
 * @features_valid: were features initialized? for legacy guests
 */
struct vdpa_device {
	struct device dev;
	struct device *dma_dev;
	const struct vdpa_config_ops *config;
	unsigned int index;
	bool features_valid;
	int nvqs;
};

/**
 * vDPA_config_ops - operations for configuring a vDPA device.
 * Note: vDPA device drivers are required to implement all of the
 * operations unless it is mentioned to be optional in the following
 * list.
 *
 * @set_vq_address:		Set the address of virtqueue
 *				@vdev: vdpa device
 *				@idx: virtqueue index
 *				@desc_area: address of desc area
 *				@driver_area: address of driver area
 *				@device_area: address of device area
 *				Returns integer: success (0) or error (< 0)
 * @set_vq_num:			Set the size of virtqueue
 *				@vdev: vdpa device
 *				@idx: virtqueue index
 *				@num: the size of virtqueue
 * @kick_vq:			Kick the virtqueue
 *				@vdev: vdpa device
 *				@idx: virtqueue index
 * @set_vq_cb:			Set the interrupt callback function for
 *				a virtqueue
 *				@vdev: vdpa device
 *				@idx: virtqueue index
 *				@cb: virtio-vdev interrupt callback structure
 * @set_vq_ready:		Set ready status for a virtqueue
 *				@vdev: vdpa device
 *				@idx: virtqueue index
 *				@ready: ready (true) not ready(false)
 * @get_vq_ready:		Get ready status for a virtqueue
 *				@vdev: vdpa device
 *				@idx: virtqueue index
 *				Returns boolean: ready (true) or not (false)
 * @set_vq_state:		Set the state for a virtqueue
 *				@vdev: vdpa device
 *				@idx: virtqueue index
 *				@state: pointer to set virtqueue state (last_avail_idx)
 *				Returns integer: success (0) or error (< 0)
 * @get_vq_state:		Get the state for a virtqueue
 *				@vdev: vdpa device
 *				@idx: virtqueue index
 *				@state: pointer to returned state (last_avail_idx)
 * @get_vq_notification: 	Get the notification area for a virtqueue
 *				@vdev: vdpa device
 *				@idx: virtqueue index
 *				Returns the notifcation area
 * @get_vq_irq:			Get the irq number of a virtqueue (optional,
 *				but must implemented if require vq irq offloading)
 *				@vdev: vdpa device
 *				@idx: virtqueue index
 *				Returns int: irq number of a virtqueue,
 *				negative number if no irq assigned.
 * @get_vq_align:		Get the virtqueue align requirement
 *				for the device
 *				@vdev: vdpa device
 *				Returns virtqueue algin requirement
 * @get_features:		Get virtio features supported by the device
 *				@vdev: vdpa device
 *				Returns the virtio features support by the
 *				device
 * @set_features:		Set virtio features supported by the driver
 *				@vdev: vdpa device
 *				@features: feature support by the driver
 *				Returns integer: success (0) or error (< 0)
 * @set_config_cb:		Set the config interrupt callback
 *				@vdev: vdpa device
 *				@cb: virtio-vdev interrupt callback structure
 * @get_vq_num_max:		Get the max size of virtqueue
 *				@vdev: vdpa device
 *				Returns u16: max size of virtqueue
 * @get_device_id:		Get virtio device id
 *				@vdev: vdpa device
 *				Returns u32: virtio device id
 * @get_vendor_id:		Get id for the vendor that provides this device
 *				@vdev: vdpa device
 *				Returns u32: virtio vendor id
 * @get_status:			Get the device status
 *				@vdev: vdpa device
 *				Returns u8: virtio device status
 * @set_status:			Set the device status
 *				@vdev: vdpa device
 *				@status: virtio device status
 * @get_config:			Read from device specific configuration space
 *				@vdev: vdpa device
 *				@offset: offset from the beginning of
 *				configuration space
 *				@buf: buffer used to read to
 *				@len: the length to read from
 *				configuration space
 * @set_config:			Write to device specific configuration space
 *				@vdev: vdpa device
 *				@offset: offset from the beginning of
 *				configuration space
 *				@buf: buffer used to write from
 *				@len: the length to write to
 *				configuration space
 * @get_generation:		Get device config generation (optional)
 *				@vdev: vdpa device
 *				Returns u32: device generation
 * @set_map:			Set device memory mapping (optional)
 *				Needed for device that using device
 *				specific DMA translation (on-chip IOMMU)
 *				@vdev: vdpa device
 *				@iotlb: vhost memory mapping to be
 *				used by the vDPA
 *				Returns integer: success (0) or error (< 0)
 * @dma_map:			Map an area of PA to IOVA (optional)
 *				Needed for device that using device
 *				specific DMA translation (on-chip IOMMU)
 *				and preferring incremental map.
 *				@vdev: vdpa device
 *				@iova: iova to be mapped
 *				@size: size of the area
 *				@pa: physical address for the map
 *				@perm: device access permission (VHOST_MAP_XX)
 *				Returns integer: success (0) or error (< 0)
 * @dma_unmap:			Unmap an area of IOVA (optional but
 *				must be implemented with dma_map)
 *				Needed for device that using device
 *				specific DMA translation (on-chip IOMMU)
 *				and preferring incremental unmap.
 *				@vdev: vdpa device
 *				@iova: iova to be unmapped
 *				@size: size of the area
 *				Returns integer: success (0) or error (< 0)
 * @free:			Free resources that belongs to vDPA (optional)
 *				@vdev: vdpa device
 */
struct vdpa_config_ops {
	/* Virtqueue ops */
	int (*set_vq_address)(struct vdpa_device *vdev,
			      u16 idx, u64 desc_area, u64 driver_area,
			      u64 device_area);
	void (*set_vq_num)(struct vdpa_device *vdev, u16 idx, u32 num);
	void (*kick_vq)(struct vdpa_device *vdev, u16 idx);
	void (*set_vq_cb)(struct vdpa_device *vdev, u16 idx,
			  struct vdpa_callback *cb);
	void (*set_vq_ready)(struct vdpa_device *vdev, u16 idx, bool ready);
	bool (*get_vq_ready)(struct vdpa_device *vdev, u16 idx);
	int (*set_vq_state)(struct vdpa_device *vdev, u16 idx,
			    const struct vdpa_vq_state *state);
	int (*get_vq_state)(struct vdpa_device *vdev, u16 idx,
			    struct vdpa_vq_state *state);
	struct vdpa_notification_area
	(*get_vq_notification)(struct vdpa_device *vdev, u16 idx);
	/* vq irq is not expected to be changed once DRIVER_OK is set */
	int (*get_vq_irq)(struct vdpa_device *vdv, u16 idx);

	/* Device ops */
	u32 (*get_vq_align)(struct vdpa_device *vdev);
	u64 (*get_features)(struct vdpa_device *vdev);
	int (*set_features)(struct vdpa_device *vdev, u64 features);
	void (*set_config_cb)(struct vdpa_device *vdev,
			      struct vdpa_callback *cb);
	u16 (*get_vq_num_max)(struct vdpa_device *vdev);
	u32 (*get_device_id)(struct vdpa_device *vdev);
	u32 (*get_vendor_id)(struct vdpa_device *vdev);
	u8 (*get_status)(struct vdpa_device *vdev);
	void (*set_status)(struct vdpa_device *vdev, u8 status);
	void (*get_config)(struct vdpa_device *vdev, unsigned int offset,
			   void *buf, unsigned int len);
	void (*set_config)(struct vdpa_device *vdev, unsigned int offset,
			   const void *buf, unsigned int len);
	u32 (*get_generation)(struct vdpa_device *vdev);

	/* DMA ops */
	int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
	int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
		       u64 pa, u32 perm);
	int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);

	/* Free device resources */
	void (*free)(struct vdpa_device *vdev);
};

struct vdpa_device *__vdpa_alloc_device(struct device *parent,
					const struct vdpa_config_ops *config,
					int nvqs,
					size_t size);

#define vdpa_alloc_device(dev_struct, member, parent, config, nvqs)   \
			  container_of(__vdpa_alloc_device( \
				       parent, config, nvqs, \
				       sizeof(dev_struct) + \
				       BUILD_BUG_ON_ZERO(offsetof( \
				       dev_struct, member))), \
				       dev_struct, member)

int vdpa_register_device(struct vdpa_device *vdev);
void vdpa_unregister_device(struct vdpa_device *vdev);

/**
 * vdpa_driver - operations for a vDPA driver
 * @driver: underlying device driver
 * @probe: the function to call when a device is found.  Returns 0 or -errno.
 * @remove: the function to call when a device is removed.
 */
struct vdpa_driver {
	struct device_driver driver;
	int (*probe)(struct vdpa_device *vdev);
	void (*remove)(struct vdpa_device *vdev);
};

#define vdpa_register_driver(drv) \
	__vdpa_register_driver(drv, THIS_MODULE)
int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner);
void vdpa_unregister_driver(struct vdpa_driver *drv);

#define module_vdpa_driver(__vdpa_driver) \
	module_driver(__vdpa_driver, vdpa_register_driver,	\
		      vdpa_unregister_driver)

static inline struct vdpa_driver *drv_to_vdpa(struct device_driver *driver)
{
	return container_of(driver, struct vdpa_driver, driver);
}

static inline struct vdpa_device *dev_to_vdpa(struct device *_dev)
{
	return container_of(_dev, struct vdpa_device, dev);
}

static inline void *vdpa_get_drvdata(const struct vdpa_device *vdev)
{
	return dev_get_drvdata(&vdev->dev);
}

static inline void vdpa_set_drvdata(struct vdpa_device *vdev, void *data)
{
	dev_set_drvdata(&vdev->dev, data);
}

static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev)
{
	return vdev->dma_dev;
}

static inline void vdpa_reset(struct vdpa_device *vdev)
{
        const struct vdpa_config_ops *ops = vdev->config;

	vdev->features_valid = false;
        ops->set_status(vdev, 0);
}

static inline int vdpa_set_features(struct vdpa_device *vdev, u64 features)
{
        const struct vdpa_config_ops *ops = vdev->config;

	vdev->features_valid = true;
        return ops->set_features(vdev, features);
}


static inline void vdpa_get_config(struct vdpa_device *vdev, unsigned offset,
				   void *buf, unsigned int len)
{
        const struct vdpa_config_ops *ops = vdev->config;

	/*
	 * Config accesses aren't supposed to trigger before features are set.
	 * If it does happen we assume a legacy guest.
	 */
	if (!vdev->features_valid)
		vdpa_set_features(vdev, 0);
	ops->get_config(vdev, offset, buf, len);
}

#endif /* _LINUX_VDPA_H */
Commit	Line	Data
961e9c84 JW	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/vhost_iotlb.h>
	9
	10	/**
	11	* vDPA callback definition.
	12	* @callback: interrupt callback function
	13	* @private: the data passed to the callback function
	14	*/
	15	struct vdpa_callback {
	16	irqreturn_t (callback)(void data);
	17	void *private;
	18	};
	19
c25a26e6 JW	20	/**
	21	* vDPA notification area
	22	* @addr: base address of the notification area
	23	* @size: size of the notification area
	24	*/
	25	struct vdpa_notification_area {
	26	resource_size_t addr;
	27	resource_size_t size;
	28	};
	29
aac50c0b EC	30	/**
	31	* vDPA vq_state definition
	32	* @avail_index: available index
	33	*/
	34	struct vdpa_vq_state {
	35	u16 avail_index;
	36	};
	37
961e9c84 JW	38	/**
	39	* vDPA device - representation of a vDPA device
	40	* @dev: underlying device
	41	* @dma_dev: the actual device that is performing DMA
	42	* @config: the configuration ops for this device.
	43	* @index: device index
452639a6	44	* @features_valid: were features initialized? for legacy guests
961e9c84 JW	45	*/
	46	struct vdpa_device {
	47	struct device dev;
	48	struct device *dma_dev;
	49	const struct vdpa_config_ops *config;
	50	unsigned int index;
452639a6	51	bool features_valid;
a9974489	52	int nvqs;
961e9c84 JW	53	};
	54
	55	/**
	56	* vDPA_config_ops - operations for configuring a vDPA device.
	57	* Note: vDPA device drivers are required to implement all of the
	58	* operations unless it is mentioned to be optional in the following
	59	* list.
	60	*
	61	* @set_vq_address: Set the address of virtqueue
	62	* @vdev: vdpa device
	63	* @idx: virtqueue index
	64	* @desc_area: address of desc area
	65	* @driver_area: address of driver area
	66	* @device_area: address of device area
	67	* Returns integer: success (0) or error (< 0)
	68	* @set_vq_num: Set the size of virtqueue
	69	* @vdev: vdpa device
	70	* @idx: virtqueue index
	71	* @num: the size of virtqueue
	72	* @kick_vq: Kick the virtqueue
	73	* @vdev: vdpa device
	74	* @idx: virtqueue index
	75	* @set_vq_cb: Set the interrupt callback function for
	76	* a virtqueue
	77	* @vdev: vdpa device
	78	* @idx: virtqueue index
	79	* @cb: virtio-vdev interrupt callback structure
	80	* @set_vq_ready: Set ready status for a virtqueue
	81	* @vdev: vdpa device
	82	* @idx: virtqueue index
	83	* @ready: ready (true) not ready(false)
	84	* @get_vq_ready: Get ready status for a virtqueue
	85	* @vdev: vdpa device
	86	* @idx: virtqueue index
	87	* Returns boolean: ready (true) or not (false)
	88	* @set_vq_state: Set the state for a virtqueue
	89	* @vdev: vdpa device
	90	* @idx: virtqueue index
aac50c0b	91	* @state: pointer to set virtqueue state (last_avail_idx)
961e9c84 JW	92	* Returns integer: success (0) or error (< 0)
	93	* @get_vq_state: Get the state for a virtqueue
	94	* @vdev: vdpa device
	95	* @idx: virtqueue index
aac50c0b	96	* @state: pointer to returned state (last_avail_idx)
c25a26e6 JW	97	* @get_vq_notification: Get the notification area for a virtqueue
	98	* @vdev: vdpa device
	99	* @idx: virtqueue index
	100	* Returns the notifcation area
7164675a ZL	101	* @get_vq_irq: Get the irq number of a virtqueue (optional,
	102	* but must implemented if require vq irq offloading)
	103	* @vdev: vdpa device
	104	* @idx: virtqueue index
	105	* Returns int: irq number of a virtqueue,
	106	* negative number if no irq assigned.
961e9c84 JW	107	* @get_vq_align: Get the virtqueue align requirement
	108	* for the device
	109	* @vdev: vdpa device
	110	* Returns virtqueue algin requirement
	111	* @get_features: Get virtio features supported by the device
	112	* @vdev: vdpa device
	113	* Returns the virtio features support by the
	114	* device
	115	* @set_features: Set virtio features supported by the driver
	116	* @vdev: vdpa device
	117	* @features: feature support by the driver
	118	* Returns integer: success (0) or error (< 0)
	119	* @set_config_cb: Set the config interrupt callback
	120	* @vdev: vdpa device
	121	* @cb: virtio-vdev interrupt callback structure
	122	* @get_vq_num_max: Get the max size of virtqueue
	123	* @vdev: vdpa device
	124	* Returns u16: max size of virtqueue
	125	* @get_device_id: Get virtio device id
	126	* @vdev: vdpa device
	127	* Returns u32: virtio device id
	128	* @get_vendor_id: Get id for the vendor that provides this device
	129	* @vdev: vdpa device
	130	* Returns u32: virtio vendor id
	131	* @get_status: Get the device status
	132	* @vdev: vdpa device
	133	* Returns u8: virtio device status
	134	* @set_status: Set the device status
	135	* @vdev: vdpa device
	136	* @status: virtio device status
	137	* @get_config: Read from device specific configuration space
	138	* @vdev: vdpa device
	139	* @offset: offset from the beginning of
	140	* configuration space
	141	* @buf: buffer used to read to
	142	* @len: the length to read from
	143	* configuration space
	144	* @set_config: Write to device specific configuration space
	145	* @vdev: vdpa device
	146	* @offset: offset from the beginning of
	147	* configuration space
	148	* @buf: buffer used to write from
	149	* @len: the length to write to
	150	* configuration space
	151	* @get_generation: Get device config generation (optional)
	152	* @vdev: vdpa device
	153	* Returns u32: device generation
	154	* @set_map: Set device memory mapping (optional)
	155	* Needed for device that using device
	156	* specific DMA translation (on-chip IOMMU)
	157	* @vdev: vdpa device
	158	* @iotlb: vhost memory mapping to be
	159	* used by the vDPA
	160	* Returns integer: success (0) or error (< 0)
	161	* @dma_map: Map an area of PA to IOVA (optional)
	162	* Needed for device that using device
	163	* specific DMA translation (on-chip IOMMU)
	164	* and preferring incremental map.
	165	* @vdev: vdpa device
	166	* @iova: iova to be mapped
	167	* @size: size of the area
	168	* @pa: physical address for the map
	169	* @perm: device access permission (VHOST_MAP_XX)
	170	* Returns integer: success (0) or error (< 0)
171	* @dma_unmap: Unmap an area of IOVA (optional but
172	* must be implemented with dma_map)
173	* Needed for device that using device
174	* specific DMA translation (on-chip IOMMU)
175	* and preferring incremental unmap.
176	* @vdev: vdpa device
177	* @iova: iova to be unmapped
178	* @size: size of the area
179	* Returns integer: success (0) or error (< 0)
180	* @free: Free resources that belongs to vDPA (optional)
181	* @vdev: vdpa device
182	*/
183	struct vdpa_config_ops {
184	/* Virtqueue ops */
185	int (set_vq_address)(struct vdpa_device vdev,
186	u16 idx, u64 desc_area, u64 driver_area,
187	u64 device_area);
188	void (set_vq_num)(struct vdpa_device vdev, u16 idx, u32 num);
189	void (kick_vq)(struct vdpa_device vdev, u16 idx);
190	void (set_vq_cb)(struct vdpa_device vdev, u16 idx,
191	struct vdpa_callback *cb);
192	void (set_vq_ready)(struct vdpa_device vdev, u16 idx, bool ready);
193	bool (get_vq_ready)(struct vdpa_device vdev, u16 idx);
aac50c0b EC	194	int (set_vq_state)(struct vdpa_device vdev, u16 idx,
aac50c0b EC	195	const struct vdpa_vq_state *state);
23750e39 EC	196	int (get_vq_state)(struct vdpa_device vdev, u16 idx,
23750e39 EC	197	struct vdpa_vq_state *state);
c25a26e6 JW	198	struct vdpa_notification_area
c25a26e6 JW	199	(get_vq_notification)(struct vdpa_device vdev, u16 idx);
4c05433b	200	/* vq irq is not expected to be changed once DRIVER_OK is set */
7164675a	201	int (get_vq_irq)(struct vdpa_device vdv, u16 idx);
961e9c84 JW	202
961e9c84 JW	203	/* Device ops */
425a5070	204	u32 (get_vq_align)(struct vdpa_device vdev);
961e9c84 JW	205	u64 (get_features)(struct vdpa_device vdev);
	206	int (set_features)(struct vdpa_device vdev, u64 features);
	207	void (set_config_cb)(struct vdpa_device vdev,
	208	struct vdpa_callback *cb);
	209	u16 (get_vq_num_max)(struct vdpa_device vdev);
	210	u32 (get_device_id)(struct vdpa_device vdev);
	211	u32 (get_vendor_id)(struct vdpa_device vdev);
	212	u8 (get_status)(struct vdpa_device vdev);
	213	void (set_status)(struct vdpa_device vdev, u8 status);
	214	void (get_config)(struct vdpa_device vdev, unsigned int offset,
	215	void *buf, unsigned int len);
	216	void (set_config)(struct vdpa_device vdev, unsigned int offset,
	217	const void *buf, unsigned int len);
	218	u32 (get_generation)(struct vdpa_device vdev);
	219
	220	/* DMA ops */
	221	int (set_map)(struct vdpa_device vdev, struct vhost_iotlb *iotlb);
	222	int (dma_map)(struct vdpa_device vdev, u64 iova, u64 size,
	223	u64 pa, u32 perm);
	224	int (dma_unmap)(struct vdpa_device vdev, u64 iova, u64 size);
	225
	226	/* Free device resources */
	227	void (free)(struct vdpa_device vdev);
	228	};
	229
	230	struct vdpa_device __vdpa_alloc_device(struct device parent,
	231	const struct vdpa_config_ops *config,
a9974489	232	int nvqs,
961e9c84 JW	233	size_t size);
961e9c84 JW	234
a9974489	235	#define vdpa_alloc_device(dev_struct, member, parent, config, nvqs) \
961e9c84	236	container_of(__vdpa_alloc_device( \
a9974489	237	parent, config, nvqs, \
961e9c84 JW	238	sizeof(dev_struct) + \
	239	BUILD_BUG_ON_ZERO(offsetof( \
	240	dev_struct, member))), \
	241	dev_struct, member)
	242
	243	int vdpa_register_device(struct vdpa_device *vdev);
	244	void vdpa_unregister_device(struct vdpa_device *vdev);
	245
	246	/**
	247	* vdpa_driver - operations for a vDPA driver
	248	* @driver: underlying device driver
	249	* @probe: the function to call when a device is found. Returns 0 or -errno.
	250	* @remove: the function to call when a device is removed.
	251	*/
	252	struct vdpa_driver {
	253	struct device_driver driver;
	254	int (probe)(struct vdpa_device vdev);
	255	void (remove)(struct vdpa_device vdev);
	256	};
	257
	258	#define vdpa_register_driver(drv) \
	259	__vdpa_register_driver(drv, THIS_MODULE)
	260	int __vdpa_register_driver(struct vdpa_driver drv, struct module owner);
	261	void vdpa_unregister_driver(struct vdpa_driver *drv);
	262
	263	#define module_vdpa_driver(__vdpa_driver) \
	264	module_driver(__vdpa_driver, vdpa_register_driver, \
	265	vdpa_unregister_driver)
	266
	267	static inline struct vdpa_driver drv_to_vdpa(struct device_driver driver)
	268	{
	269	return container_of(driver, struct vdpa_driver, driver);
	270	}
	271
	272	static inline struct vdpa_device dev_to_vdpa(struct device _dev)
	273	{
	274	return container_of(_dev, struct vdpa_device, dev);
	275	}
	276
	277	static inline void vdpa_get_drvdata(const struct vdpa_device vdev)
	278	{
	279	return dev_get_drvdata(&vdev->dev);
	280	}
	281
	282	static inline void vdpa_set_drvdata(struct vdpa_device vdev, void data)
	283	{
	284	dev_set_drvdata(&vdev->dev, data);
	285	}
	286
	287	static inline struct device vdpa_get_dma_dev(struct vdpa_device vdev)
	288	{
	289	return vdev->dma_dev;
	290	}
452639a6 MT	291
	292	static inline void vdpa_reset(struct vdpa_device *vdev)
	293	{
	294	const struct vdpa_config_ops *ops = vdev->config;
	295
	296	vdev->features_valid = false;
	297	ops->set_status(vdev, 0);
	298	}
	299
	300	static inline int vdpa_set_features(struct vdpa_device *vdev, u64 features)
	301	{
	302	const struct vdpa_config_ops *ops = vdev->config;
	303
	304	vdev->features_valid = true;
	305	return ops->set_features(vdev, features);
	306	}
	307
	308
	309	static inline void vdpa_get_config(struct vdpa_device *vdev, unsigned offset,
	310	void *buf, unsigned int len)
	311	{
	312	const struct vdpa_config_ops *ops = vdev->config;
	313
	314	/*
	315	* Config accesses aren't supposed to trigger before features are set.
	316	* If it does happen we assume a legacy guest.
	317	*/
	318	if (!vdev->features_valid)
	319	vdpa_set_features(vdev, 0);
	320	ops->get_config(vdev, offset, buf, len);
	321	}
	322
961e9c84	323	#endif /* _LINUX_VDPA_H */