drivers/vhost/vhost.h - linux/torvalds/linux - Git at Google

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

 #include <linux/eventfd.h>
 #include <linux/vhost.h>
 #include <linux/mm.h>
 #include <linux/mutex.h>
 #include <linux/poll.h>
 #include <linux/file.h>
 #include <linux/uio.h>
 #include <linux/virtio_config.h>
 #include <linux/virtio_ring.h>
 #include <linux/atomic.h>

 struct vhost_work;
 typedef void (*vhost_work_fn_t)(struct vhost_work *work);

 #define VHOST_WORK_QUEUED 1
 struct vhost_work {
 	struct llist_node	  node;
 	vhost_work_fn_t		  fn;
 	unsigned long		  flags;
 };

 /* Poll a file (eventfd or socket) */
 /* Note: there's nothing vhost specific about this structure. */
 struct vhost_poll {
 	poll_table                table;
 	wait_queue_head_t        *wqh;
 	wait_queue_entry_t              wait;
 	struct vhost_work	  work;
 	__poll_t		  mask;
 	struct vhost_dev	 *dev;
 };

 void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
 bool vhost_has_work(struct vhost_dev *dev);

 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
 		     __poll_t mask, struct vhost_dev *dev);
 int vhost_poll_start(struct vhost_poll *poll, struct file *file);
 void vhost_poll_stop(struct vhost_poll *poll);
 void vhost_poll_flush(struct vhost_poll *poll);
 void vhost_poll_queue(struct vhost_poll *poll);
 void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);

 struct vhost_log {
 	u64 addr;
 	u64 len;
 };

 #define START(node) ((node)->start)
 #define LAST(node) ((node)->last)

 struct vhost_umem_node {
 	struct rb_node rb;
 	struct list_head link;
 	__u64 start;
 	__u64 last;
 	__u64 size;
 	__u64 userspace_addr;
 	__u32 perm;
 	__u32 flags_padding;
 	__u64 __subtree_last;
 };

 struct vhost_umem {
 	struct rb_root_cached umem_tree;
 	struct list_head umem_list;
 	int numem;
 };

 enum vhost_uaddr_type {
 	VHOST_ADDR_DESC = 0,
 	VHOST_ADDR_AVAIL = 1,
 	VHOST_ADDR_USED = 2,
 	VHOST_NUM_ADDRS = 3,
 };

 /* The virtqueue structure describes a queue attached to a device. */
 struct vhost_virtqueue {
 	struct vhost_dev *dev;

 	/* The actual ring of buffers. */
 	struct mutex mutex;
 	unsigned int num;
 	struct vring_desc __user *desc;
 	struct vring_avail __user *avail;
 	struct vring_used __user *used;
 	const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
 	struct file *kick;
 	struct eventfd_ctx *call_ctx;
 	struct eventfd_ctx *error_ctx;
 	struct eventfd_ctx *log_ctx;

 	struct vhost_poll poll;

 	/* The routine to call when the Guest pings us, or timeout. */
 	vhost_work_fn_t handle_kick;

 	/* Last available index we saw. */
 	u16 last_avail_idx;

 	/* Caches available index value from user. */
 	u16 avail_idx;

 	/* Last index we used. */
 	u16 last_used_idx;

 	/* Used flags */
 	u16 used_flags;

 	/* Last used index value we have signalled on */
 	u16 signalled_used;

 	/* Last used index value we have signalled on */
 	bool signalled_used_valid;

 	/* Log writes to used structure. */
 	bool log_used;
 	u64 log_addr;

 	struct iovec iov[UIO_MAXIOV];
 	struct iovec iotlb_iov[64];
 	struct iovec *indirect;
 	struct vring_used_elem *heads;
 	/* Protected by virtqueue mutex. */
 	struct vhost_umem *umem;
 	struct vhost_umem *iotlb;
 	void *private_data;
 	u64 acked_features;
 	u64 acked_backend_features;
 	/* Log write descriptors */
 	void __user *log_base;
 	struct vhost_log *log;

 	/* Ring endianness. Defaults to legacy native endianness.
 	 * Set to true when starting a modern virtio device. */
 	bool is_le;
 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
 	/* Ring endianness requested by userspace for cross-endian support. */
 	bool user_be;
 #endif
 	u32 busyloop_timeout;
 };

 struct vhost_msg_node {
   union {
 	  struct vhost_msg msg;
 	  struct vhost_msg_v2 msg_v2;
   };
   struct vhost_virtqueue *vq;
   struct list_head node;
 };

 struct vhost_dev {
 	struct mm_struct *mm;
 	struct mutex mutex;
 	struct vhost_virtqueue **vqs;
 	int nvqs;
 	struct eventfd_ctx *log_ctx;
 	struct llist_head work_list;
 	struct task_struct *worker;
 	struct vhost_umem *umem;
 	struct vhost_umem *iotlb;
 	spinlock_t iotlb_lock;
 	struct list_head read_list;
 	struct list_head pending_list;
 	wait_queue_head_t wait;
 	int iov_limit;
 	int weight;
 	int byte_weight;
 };

 bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
 		    int nvqs, int iov_limit, int weight, int byte_weight);
 long vhost_dev_set_owner(struct vhost_dev *dev);
 bool vhost_dev_has_owner(struct vhost_dev *dev);
 long vhost_dev_check_owner(struct vhost_dev *);
 struct vhost_umem *vhost_dev_reset_owner_prepare(void);
 void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
 void vhost_dev_cleanup(struct vhost_dev *);
 void vhost_dev_stop(struct vhost_dev *);
 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
 bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
 bool vhost_log_access_ok(struct vhost_dev *);

 int vhost_get_vq_desc(struct vhost_virtqueue *,
 		      struct iovec iov[], unsigned int iov_count,
 		      unsigned int *out_num, unsigned int *in_num,
 		      struct vhost_log *log, unsigned int *log_num);
 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);

 int vhost_vq_init_access(struct vhost_virtqueue *);
 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
 		     unsigned count);
 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
 			       unsigned int id, int len);
 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
 			       struct vring_used_elem *heads, unsigned count);
 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);

 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
 		    unsigned int log_num, u64 len,
 		    struct iovec *iov, int count);
 int vq_meta_prefetch(struct vhost_virtqueue *vq);

 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
 void vhost_enqueue_msg(struct vhost_dev *dev,
 		       struct list_head *head,
 		       struct vhost_msg_node *node);
 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
 					 struct list_head *head);
 __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev,
 			    poll_table *wait);
 ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
 			    int noblock);
 ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
 			     struct iov_iter *from);
 int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);

 #define vq_err(vq, fmt, ...) do {                                  \
 		pr_debug(pr_fmt(fmt), ##__VA_ARGS__);       \
 		if ((vq)->error_ctx)                               \
 				eventfd_signal((vq)->error_ctx, 1);\
 	} while (0)

 enum {
 	VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
 			 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
 			 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
 			 (1ULL << VHOST_F_LOG_ALL) |
 			 (1ULL << VIRTIO_F_ANY_LAYOUT) |
 			 (1ULL << VIRTIO_F_VERSION_1)
 };

 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
 {
 	return vq->acked_features & (1ULL << bit);
 }

 static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit)
 {
 	return vq->acked_backend_features & (1ULL << bit);
 }

 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
 {
 	return vq->is_le;
 }
 #else
 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
 {
 	return virtio_legacy_is_little_endian() || vq->is_le;
 }
 #endif

 /* Memory accessors */
 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
 {
 	return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
 }

 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
 {
 	return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
 }

 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
 {
 	return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
 }

 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
 {
 	return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
 }

 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
 {
 	return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
 }

 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
 {
 	return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
 }
 #endif
	/* SPDX-License-Identifier: GPL-2.0 */
	#ifndef _VHOST_H
	#define _VHOST_H

	#include <linux/eventfd.h>
	#include <linux/vhost.h>
	#include <linux/mm.h>
	#include <linux/mutex.h>
	#include <linux/poll.h>
	#include <linux/file.h>
	#include <linux/uio.h>
	#include <linux/virtio_config.h>
	#include <linux/virtio_ring.h>
	#include <linux/atomic.h>

	struct vhost_work;
	typedef void (vhost_work_fn_t)(struct vhost_work work);

	#define VHOST_WORK_QUEUED 1
	struct vhost_work {
	struct llist_node node;
	vhost_work_fn_t fn;
	unsigned long flags;
	};

	/* Poll a file (eventfd or socket) */
	/* Note: there's nothing vhost specific about this structure. */
	struct vhost_poll {
	poll_table table;
	wait_queue_head_t *wqh;
	wait_queue_entry_t wait;
	struct vhost_work work;
	__poll_t mask;
	struct vhost_dev *dev;
	};

	void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
	void vhost_work_queue(struct vhost_dev dev, struct vhost_work work);
	bool vhost_has_work(struct vhost_dev *dev);

	void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
	__poll_t mask, struct vhost_dev *dev);
	int vhost_poll_start(struct vhost_poll poll, struct file file);
	void vhost_poll_stop(struct vhost_poll *poll);
	void vhost_poll_flush(struct vhost_poll *poll);
	void vhost_poll_queue(struct vhost_poll *poll);
	void vhost_work_flush(struct vhost_dev dev, struct vhost_work work);
	long vhost_vring_ioctl(struct vhost_dev d, unsigned int ioctl, void __user argp);

	struct vhost_log {
	u64 addr;
	u64 len;
	};

	#define START(node) ((node)->start)
	#define LAST(node) ((node)->last)

	struct vhost_umem_node {
	struct rb_node rb;
	struct list_head link;
	__u64 start;
	__u64 last;
	__u64 size;
	__u64 userspace_addr;
	__u32 perm;
	__u32 flags_padding;
	__u64 __subtree_last;
	};

	struct vhost_umem {
	struct rb_root_cached umem_tree;
	struct list_head umem_list;
	int numem;
	};

	enum vhost_uaddr_type {
	VHOST_ADDR_DESC = 0,
	VHOST_ADDR_AVAIL = 1,
	VHOST_ADDR_USED = 2,
	VHOST_NUM_ADDRS = 3,
	};

	/* The virtqueue structure describes a queue attached to a device. */
	struct vhost_virtqueue {
	struct vhost_dev *dev;

	/* The actual ring of buffers. */
	struct mutex mutex;
	unsigned int num;
	struct vring_desc __user *desc;
	struct vring_avail __user *avail;
	struct vring_used __user *used;
	const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
	struct file *kick;
	struct eventfd_ctx *call_ctx;
	struct eventfd_ctx *error_ctx;
	struct eventfd_ctx *log_ctx;

	struct vhost_poll poll;

	/* The routine to call when the Guest pings us, or timeout. */
	vhost_work_fn_t handle_kick;

	/* Last available index we saw. */
	u16 last_avail_idx;

	/* Caches available index value from user. */
	u16 avail_idx;

	/* Last index we used. */
	u16 last_used_idx;

	/* Used flags */
	u16 used_flags;

	/* Last used index value we have signalled on */
	u16 signalled_used;

	/* Last used index value we have signalled on */
	bool signalled_used_valid;

	/* Log writes to used structure. */
	bool log_used;
	u64 log_addr;

	struct iovec iov[UIO_MAXIOV];
	struct iovec iotlb_iov[64];
	struct iovec *indirect;
	struct vring_used_elem *heads;
	/* Protected by virtqueue mutex. */
	struct vhost_umem *umem;
	struct vhost_umem *iotlb;
	void *private_data;
	u64 acked_features;
	u64 acked_backend_features;
	/* Log write descriptors */
	void __user *log_base;
	struct vhost_log *log;

	/* Ring endianness. Defaults to legacy native endianness.
	* Set to true when starting a modern virtio device. */
	bool is_le;
	#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
	/* Ring endianness requested by userspace for cross-endian support. */
	bool user_be;
	#endif
	u32 busyloop_timeout;
	};

	struct vhost_msg_node {
	union {
	struct vhost_msg msg;
	struct vhost_msg_v2 msg_v2;
	};
	struct vhost_virtqueue *vq;
	struct list_head node;
	};

	struct vhost_dev {
	struct mm_struct *mm;
	struct mutex mutex;
	struct vhost_virtqueue **vqs;
	int nvqs;
	struct eventfd_ctx *log_ctx;
	struct llist_head work_list;
	struct task_struct *worker;
	struct vhost_umem *umem;
	struct vhost_umem *iotlb;
	spinlock_t iotlb_lock;
	struct list_head read_list;
	struct list_head pending_list;
	wait_queue_head_t wait;
	int iov_limit;
	int weight;
	int byte_weight;
	};

	bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
	void vhost_dev_init(struct vhost_dev , struct vhost_virtqueue *vqs,
	int nvqs, int iov_limit, int weight, int byte_weight);
	long vhost_dev_set_owner(struct vhost_dev *dev);
	bool vhost_dev_has_owner(struct vhost_dev *dev);
	long vhost_dev_check_owner(struct vhost_dev *);
	struct vhost_umem *vhost_dev_reset_owner_prepare(void);
	void vhost_dev_reset_owner(struct vhost_dev , struct vhost_umem );
	void vhost_dev_cleanup(struct vhost_dev *);
	void vhost_dev_stop(struct vhost_dev *);
	long vhost_dev_ioctl(struct vhost_dev , unsigned int ioctl, void __user argp);
	long vhost_vring_ioctl(struct vhost_dev d, unsigned int ioctl, void __user argp);
	bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
	bool vhost_log_access_ok(struct vhost_dev *);

	int vhost_get_vq_desc(struct vhost_virtqueue *,
	struct iovec iov[], unsigned int iov_count,
	unsigned int out_num, unsigned int in_num,
	struct vhost_log log, unsigned int log_num);
	void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);

	int vhost_vq_init_access(struct vhost_virtqueue *);
	int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
	int vhost_add_used_n(struct vhost_virtqueue , struct vring_used_elem heads,
	unsigned count);
	void vhost_add_used_and_signal(struct vhost_dev , struct vhost_virtqueue ,
	unsigned int id, int len);
	void vhost_add_used_and_signal_n(struct vhost_dev , struct vhost_virtqueue ,
	struct vring_used_elem *heads, unsigned count);
	void vhost_signal(struct vhost_dev , struct vhost_virtqueue );
	void vhost_disable_notify(struct vhost_dev , struct vhost_virtqueue );
	bool vhost_vq_avail_empty(struct vhost_dev , struct vhost_virtqueue );
	bool vhost_enable_notify(struct vhost_dev , struct vhost_virtqueue );

	int vhost_log_write(struct vhost_virtqueue vq, struct vhost_log log,
	unsigned int log_num, u64 len,
	struct iovec *iov, int count);
	int vq_meta_prefetch(struct vhost_virtqueue *vq);

	struct vhost_msg_node vhost_new_msg(struct vhost_virtqueue vq, int type);
	void vhost_enqueue_msg(struct vhost_dev *dev,
	struct list_head *head,
	struct vhost_msg_node *node);
	struct vhost_msg_node vhost_dequeue_msg(struct vhost_dev dev,
	struct list_head *head);
	__poll_t vhost_chr_poll(struct file file, struct vhost_dev dev,
	poll_table *wait);
	ssize_t vhost_chr_read_iter(struct vhost_dev dev, struct iov_iter to,
	int noblock);
	ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
	struct iov_iter *from);
	int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);

	#define vq_err(vq, fmt, ...) do { \
	pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
	if ((vq)->error_ctx) \
	eventfd_signal((vq)->error_ctx, 1);\
	} while (0)

	enum {
	VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) \|
	(1ULL << VIRTIO_RING_F_INDIRECT_DESC) \|
	(1ULL << VIRTIO_RING_F_EVENT_IDX) \|
	(1ULL << VHOST_F_LOG_ALL) \|
	(1ULL << VIRTIO_F_ANY_LAYOUT) \|
	(1ULL << VIRTIO_F_VERSION_1)
	};

	static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
	{
	return vq->acked_features & (1ULL << bit);
	}

	static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit)
	{
	return vq->acked_backend_features & (1ULL << bit);
	}

	#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
	static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
	{
	return vq->is_le;
	}
	#else
	static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
	{
	return virtio_legacy_is_little_endian() \|\| vq->is_le;
	}
	#endif

	/* Memory accessors */
	static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
	{
	return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
	}

	static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
	{
	return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
	}

	static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
	{
	return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
	}

	static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
	{
	return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
	}

	static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
	{
	return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
	}

	static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
	{
	return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
	}
	#endif