include/linux/vfio.h

/*
 * VFIO API definition
 *
 * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
 *     Author: Alex Williamson <alex.williamson@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef VFIO_H
#define VFIO_H


#include <linux/iommu.h>
#include <linux/mm.h>
#include <uapi/linux/vfio.h>

/**
 * struct vfio_device_ops - VFIO bus driver device callbacks
 *
 * @open: Called when userspace creates new file descriptor for device
 * @release: Called when userspace releases file descriptor for device
 * @read: Perform read(2) on device file descriptor
 * @write: Perform write(2) on device file descriptor
 * @ioctl: Perform ioctl(2) on device file descriptor, supporting VFIO_DEVICE_*
 *         operations documented below
 * @mmap: Perform mmap(2) on a region of the device file descriptor
 */
struct vfio_device_ops {
	char	*name;
	int	(*open)(void *device_data);
	void	(*release)(void *device_data);
	ssize_t	(*read)(void *device_data, char __user *buf,
			size_t count, loff_t *ppos);
	ssize_t	(*write)(void *device_data, const char __user *buf,
			 size_t count, loff_t *size);
	long	(*ioctl)(void *device_data, unsigned int cmd,
			 unsigned long arg);
	int	(*mmap)(void *device_data, struct vm_area_struct *vma);
};

extern int vfio_add_group_dev(struct device *dev,
			      const struct vfio_device_ops *ops,
			      void *device_data);

extern void *vfio_del_group_dev(struct device *dev);
extern struct vfio_device *vfio_device_get_from_dev(struct device *dev);
extern void vfio_device_put(struct vfio_device *device);
extern void *vfio_device_data(struct vfio_device *device);

/**
 * struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks
 */
struct vfio_iommu_driver_ops {
	char		*name;
	struct module	*owner;
	void		*(*open)(unsigned long arg);
	void		(*release)(void *iommu_data);
	ssize_t		(*read)(void *iommu_data, char __user *buf,
				size_t count, loff_t *ppos);
	ssize_t		(*write)(void *iommu_data, const char __user *buf,
				 size_t count, loff_t *size);
	long		(*ioctl)(void *iommu_data, unsigned int cmd,
				 unsigned long arg);
	int		(*mmap)(void *iommu_data, struct vm_area_struct *vma);
	int		(*attach_group)(void *iommu_data,
					struct iommu_group *group);
	void		(*detach_group)(void *iommu_data,
					struct iommu_group *group);

};

extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);

extern void vfio_unregister_iommu_driver(
				const struct vfio_iommu_driver_ops *ops);

/**
 * offsetofend(TYPE, MEMBER)
 *
 * @TYPE: The type of the structure
 * @MEMBER: The member within the structure to get the end offset of
 *
 * Simple helper macro for dealing with variable sized structures passed
 * from user space.  This allows us to easily determine if the provided
 * structure is sized to include various fields.
 */
#define offsetofend(TYPE, MEMBER) ({				\
	TYPE tmp;						\
	offsetof(TYPE, MEMBER) + sizeof(tmp.MEMBER); })		\

/*
 * External user API
 */
extern struct vfio_group *vfio_group_get_external_user(struct file *filep);
extern void vfio_group_put_external_user(struct vfio_group *group);
extern int vfio_external_user_iommu_id(struct vfio_group *group);
extern long vfio_external_check_extension(struct vfio_group *group,
					  unsigned long arg);

#endif /* VFIO_H */