/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * VFIO API definition
 *
 * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
 *     Author: Alex Williamson <alex.williamson@redhat.com>
 */
#ifndef VFIO_H
#define VFIO_H


#include <linux/iommu.h>
#include <linux/mm.h>
#include <linux/workqueue.h>
#include <linux/poll.h>
#include <linux/cdev.h>
#include <uapi/linux/vfio.h>
#include <linux/iova_bitmap.h>

struct kvm;
struct iommufd_ctx;
struct iommufd_device;
struct iommufd_access;
struct vfio_info_cap;

/*
 * VFIO devices can be placed in a set, this allows all devices to share this
 * structure and the VFIO core will provide a lock that is held around
 * open_device()/close_device() for all devices in the set.
 */
struct vfio_device_set {
        void *set_id;
        struct mutex lock;
        struct list_head device_list;
        unsigned int device_count;
};

struct vfio_device {
        struct device *dev;
        const struct vfio_device_ops *ops;
        /*
         * mig_ops/log_ops is a static property of the vfio_device which must
         * be set prior to registering the vfio_device.
         */
        const struct vfio_migration_ops *mig_ops;
        const struct vfio_log_ops *log_ops;
#if IS_ENABLED(CONFIG_VFIO_GROUP)
        struct vfio_group *group;
        struct list_head group_next;
        struct list_head iommu_entry;
#endif
        struct vfio_device_set *dev_set;
        struct list_head dev_set_list;
        unsigned int migration_flags;
        struct kvm *kvm;

        /* Members below here are private, not for driver use */
        unsigned int index;
        struct device device;   /* device.kref covers object life circle */
#if IS_ENABLED(CONFIG_VFIO_DEVICE_CDEV)
        struct cdev cdev;
#endif
        refcount_t refcount;    /* user count on registered device*/
        unsigned int open_count;
        struct completion comp;
        struct iommufd_access *iommufd_access;
        void (*put_kvm)(struct kvm *kvm);
        struct inode *inode;
#if IS_ENABLED(CONFIG_IOMMUFD)
        struct iommufd_device *iommufd_device;
        struct ida pasids;
        u8 iommufd_attached:1;
#endif
        u8 cdev_opened:1;
#ifdef CONFIG_DEBUG_FS
        /*
         * debug_root is a static property of the vfio_device
         * which must be set prior to registering the vfio_device.
         */
        struct dentry *debug_root;
#endif
};

/**
 * struct vfio_device_ops - VFIO bus driver device callbacks
 *
 * @name: Name of the device driver.
 * @init: initialize private fields in device structure
 * @release: Reclaim private fields in device structure
 * @bind_iommufd: Called when binding the device to an iommufd
 * @unbind_iommufd: Opposite of bind_iommufd
 * @attach_ioas: Called when attaching device to an IOAS/HWPT managed by the
 *               bound iommufd. Undo in unbind_iommufd if @detach_ioas is not
 *               called.
 * @detach_ioas: Opposite of attach_ioas
 * @pasid_attach_ioas: The pasid variation of attach_ioas
 * @pasid_detach_ioas: Opposite of pasid_attach_ioas
 * @open_device: Called when the first file descriptor is opened for this device
 * @close_device: Opposite of open_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
 * @request: Request for the bus driver to release the device
 * @match: Optional device name match callback (return: 0 for no-match, >0 for
 *         match, -errno for abort (ex. match with insufficient or incorrect
 *         additional args)
 * @match_token_uuid: Optional device token match/validation. Return 0
 *         if the uuid is valid for the device, -errno otherwise. uuid is NULL
 *         if none was provided.
 * @dma_unmap: Called when userspace unmaps IOVA from the container
 *             this device is attached to.
 * @device_feature: Optional, fill in the VFIO_DEVICE_FEATURE ioctl
 */
struct vfio_device_ops {
        char    *name;
        int     (*init)(struct vfio_device *vdev);
        void    (*release)(struct vfio_device *vdev);
        int     (*bind_iommufd)(struct vfio_device *vdev,
                                struct iommufd_ctx *ictx, u32 *out_device_id);
        void    (*unbind_iommufd)(struct vfio_device *vdev);
        int     (*attach_ioas)(struct vfio_device *vdev, u32 *pt_id);
        void    (*detach_ioas)(struct vfio_device *vdev);
        int     (*pasid_attach_ioas)(struct vfio_device *vdev, u32 pasid,
                                     u32 *pt_id);
        void    (*pasid_detach_ioas)(struct vfio_device *vdev, u32 pasid);
        int     (*open_device)(struct vfio_device *vdev);
        void    (*close_device)(struct vfio_device *vdev);
        ssize_t (*read)(struct vfio_device *vdev, char __user *buf,
                        size_t count, loff_t *ppos);
        ssize_t (*write)(struct vfio_device *vdev, const char __user *buf,
                         size_t count, loff_t *size);
        long    (*ioctl)(struct vfio_device *vdev, unsigned int cmd,
                         unsigned long arg);
        int     (*get_region_info_caps)(struct vfio_device *vdev,
                                        struct vfio_region_info *info,
                                        struct vfio_info_cap *caps);
        int     (*mmap)(struct vfio_device *vdev, struct vm_area_struct *vma);
        void    (*request)(struct vfio_device *vdev, unsigned int count);
        int     (*match)(struct vfio_device *vdev, char *buf);
        int     (*match_token_uuid)(struct vfio_device *vdev, const uuid_t *uuid);
        void    (*dma_unmap)(struct vfio_device *vdev, u64 iova, u64 length);
        int     (*device_feature)(struct vfio_device *device, u32 flags,
                                  void __user *arg, size_t argsz);
};

#if IS_ENABLED(CONFIG_IOMMUFD)
struct iommufd_ctx *vfio_iommufd_device_ictx(struct vfio_device *vdev);
int vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx);
int vfio_iommufd_physical_bind(struct vfio_device *vdev,
                               struct iommufd_ctx *ictx, u32 *out_device_id);
void vfio_iommufd_physical_unbind(struct vfio_device *vdev);
int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev);
int vfio_iommufd_physical_pasid_attach_ioas(struct vfio_device *vdev,
                                            u32 pasid, u32 *pt_id);
void vfio_iommufd_physical_pasid_detach_ioas(struct vfio_device *vdev,
                                             u32 pasid);
int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
                               struct iommufd_ctx *ictx, u32 *out_device_id);
void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
void vfio_iommufd_emulated_detach_ioas(struct vfio_device *vdev);
#else
static inline struct iommufd_ctx *
vfio_iommufd_device_ictx(struct vfio_device *vdev)
{
        return NULL;
}

static inline int
vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx)
{
        return VFIO_PCI_DEVID_NOT_OWNED;
}

#define vfio_iommufd_physical_bind                                      \
        ((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \
                  u32 *out_device_id)) NULL)
#define vfio_iommufd_physical_unbind \
        ((void (*)(struct vfio_device *vdev)) NULL)
#define vfio_iommufd_physical_attach_ioas \
        ((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
#define vfio_iommufd_physical_detach_ioas \
        ((void (*)(struct vfio_device *vdev)) NULL)
#define vfio_iommufd_physical_pasid_attach_ioas \
        ((int (*)(struct vfio_device *vdev, u32 pasid, u32 *pt_id)) NULL)
#define vfio_iommufd_physical_pasid_detach_ioas \
        ((void (*)(struct vfio_device *vdev, u32 pasid)) NULL)
#define vfio_iommufd_emulated_bind                                      \
        ((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \
                  u32 *out_device_id)) NULL)
#define vfio_iommufd_emulated_unbind \
        ((void (*)(struct vfio_device *vdev)) NULL)
#define vfio_iommufd_emulated_attach_ioas \
        ((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
#define vfio_iommufd_emulated_detach_ioas \
        ((void (*)(struct vfio_device *vdev)) NULL)
#endif

static inline bool vfio_device_cdev_opened(struct vfio_device *device)
{
        return device->cdev_opened;
}

/**
 * struct vfio_migration_ops - VFIO bus device driver migration callbacks
 *
 * @migration_set_state: Optional callback to change the migration state for
 *         devices that support migration. It's mandatory for
 *         VFIO_DEVICE_FEATURE_MIGRATION migration support.
 *         The returned FD is used for data transfer according to the FSM
 *         definition. The driver is responsible to ensure that FD reaches end
 *         of stream or error whenever the migration FSM leaves a data transfer
 *         state or before close_device() returns.
 * @migration_get_state: Optional callback to get the migration state for
 *         devices that support migration. It's mandatory for
 *         VFIO_DEVICE_FEATURE_MIGRATION migration support.
 * @migration_get_data_size: Optional callback to get the estimated data
 *          length that will be required to complete stop copy. It's mandatory for
 *          VFIO_DEVICE_FEATURE_MIGRATION migration support.
 */
struct vfio_migration_ops {
        struct file *(*migration_set_state)(
                struct vfio_device *device,
                enum vfio_device_mig_state new_state);
        int (*migration_get_state)(struct vfio_device *device,
                                   enum vfio_device_mig_state *curr_state);
        int (*migration_get_data_size)(struct vfio_device *device,
                                       unsigned long *stop_copy_length);
};

/**
 * struct vfio_log_ops - VFIO bus device driver logging callbacks
 *
 * @log_start: Optional callback to ask the device start DMA logging.
 * @log_stop: Optional callback to ask the device stop DMA logging.
 * @log_read_and_clear: Optional callback to ask the device read
 *         and clear the dirty DMAs in some given range.
 *
 * The vfio core implementation of the DEVICE_FEATURE_DMA_LOGGING_ set
 * of features does not track logging state relative to the device,
 * therefore the device implementation of vfio_log_ops must handle
 * arbitrary user requests. This includes rejecting subsequent calls
 * to log_start without an intervening log_stop, as well as graceful
 * handling of log_stop and log_read_and_clear from invalid states.
 */
struct vfio_log_ops {
        int (*log_start)(struct vfio_device *device,
                struct rb_root_cached *ranges, u32 nnodes, u64 *page_size);
        int (*log_stop)(struct vfio_device *device);
        int (*log_read_and_clear)(struct vfio_device *device,
                unsigned long iova, unsigned long length,
                struct iova_bitmap *dirty);
};

/**
 * vfio_check_feature - Validate user input for the VFIO_DEVICE_FEATURE ioctl
 * @flags: Arg from the device_feature op
 * @argsz: Arg from the device_feature op
 * @supported_ops: Combination of VFIO_DEVICE_FEATURE_GET and SET the driver
 *                 supports
 * @minsz: Minimum data size the driver accepts
 *
 * For use in a driver's device_feature op. Checks that the inputs to the
 * VFIO_DEVICE_FEATURE ioctl are correct for the driver's feature. Returns 1 if
 * the driver should execute the get or set, otherwise the relevant
 * value should be returned.
 */
static inline int vfio_check_feature(u32 flags, size_t argsz, u32 supported_ops,
                                    size_t minsz)
{
        if ((flags & (VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_SET)) &
            ~supported_ops)
                return -EINVAL;
        if (flags & VFIO_DEVICE_FEATURE_PROBE)
                return 0;
        /* Without PROBE one of GET or SET must be requested */
        if (!(flags & (VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_SET)))
                return -EINVAL;
        if (argsz < minsz)
                return -EINVAL;
        return 1;
}

struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
                                       const struct vfio_device_ops *ops);
#define vfio_alloc_device(dev_struct, member, dev, ops)                         \
        container_of(_vfio_alloc_device(sizeof(struct dev_struct) +             \
                                        BUILD_BUG_ON_ZERO(offsetof(             \
                                                struct dev_struct, member)),    \
                                        dev, ops),                              \
                     struct dev_struct, member)

static inline void vfio_put_device(struct vfio_device *device)
{
        put_device(&device->device);
}

int vfio_register_group_dev(struct vfio_device *device);
int vfio_register_emulated_iommu_dev(struct vfio_device *device);
void vfio_unregister_group_dev(struct vfio_device *device);
bool vfio_device_try_get_registration(struct vfio_device *device);
void vfio_device_put_registration(struct vfio_device *device);

int vfio_assign_device_set(struct vfio_device *device, void *set_id);
unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set);
struct vfio_device *
vfio_find_device_in_devset(struct vfio_device_set *dev_set,
                           struct device *dev);

int vfio_mig_get_next_state(struct vfio_device *device,
                            enum vfio_device_mig_state cur_fsm,
                            enum vfio_device_mig_state new_fsm,
                            enum vfio_device_mig_state *next_fsm);

void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,
                              u32 req_nodes);

/*
 * External user API
 */
struct iommu_group *vfio_file_iommu_group(struct file *file);

#if IS_ENABLED(CONFIG_VFIO_GROUP)
bool vfio_file_is_group(struct file *file);
bool vfio_file_has_dev(struct file *file, struct vfio_device *device);
#else
static inline bool vfio_file_is_group(struct file *file)
{
        return false;
}

static inline bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
{
        return false;
}
#endif
bool vfio_file_is_valid(struct file *file);
bool vfio_file_enforced_coherent(struct file *file);
void vfio_file_set_kvm(struct file *file, struct kvm *kvm);

#define VFIO_PIN_PAGES_MAX_ENTRIES      (PAGE_SIZE/sizeof(unsigned long))

int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
                   int npage, int prot, struct page **pages);
void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage);
int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova,
                void *data, size_t len, bool write);

/*
 * Sub-module helpers
 */
struct vfio_info_cap {
        struct vfio_info_cap_header *buf;
        size_t size;
};
struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
                                               size_t size, u16 id,
                                               u16 version);
void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset);

int vfio_info_add_capability(struct vfio_info_cap *caps,
                             struct vfio_info_cap_header *cap, size_t size);

int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr,
                                       int num_irqs, int max_irq_type,
                                       size_t *data_size);

/*
 * IRQfd - generic
 */
struct virqfd {
        void                    *opaque;
        struct eventfd_ctx      *eventfd;
        int                     (*handler)(void *, void *);
        void                    (*thread)(void *, void *);
        void                    *data;
        struct work_struct      inject;
        wait_queue_entry_t              wait;
        poll_table              pt;
        struct work_struct      shutdown;
        struct work_struct      flush_inject;
        struct virqfd           **pvirqfd;
};

int vfio_virqfd_enable(void *opaque, int (*handler)(void *, void *),
                       void (*thread)(void *, void *), void *data,
                       struct virqfd **pvirqfd, int fd);
void vfio_virqfd_disable(struct virqfd **pvirqfd);
void vfio_virqfd_flush_thread(struct virqfd **pvirqfd);

#endif /* VFIO_H */