334 lines
		
	
	
		
			9.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			334 lines
		
	
	
		
			9.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef _VHOST_H
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| #define _VHOST_H
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| 
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| #include <linux/eventfd.h>
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| #include <linux/vhost.h>
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| #include <linux/mm.h>
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| #include <linux/mutex.h>
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| #include <linux/poll.h>
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| #include <linux/file.h>
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| #include <linux/uio.h>
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| #include <linux/virtio_config.h>
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| #include <linux/virtio_ring.h>
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| #include <linux/atomic.h>
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| #include <linux/vhost_iotlb.h>
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| #include <linux/irqbypass.h>
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| 
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| struct vhost_work;
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| typedef void (*vhost_work_fn_t)(struct vhost_work *work);
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| 
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| #define VHOST_WORK_QUEUED 1
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| struct vhost_work {
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| 	struct llist_node	node;
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| 	vhost_work_fn_t		fn;
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| 	unsigned long		flags;
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| };
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| 
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| struct vhost_worker {
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| 	struct task_struct	*task;
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| 	struct llist_head	work_list;
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| 	struct vhost_dev	*dev;
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| 	u64			kcov_handle;
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| };
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| 
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| /* Poll a file (eventfd or socket) */
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| /* Note: there's nothing vhost specific about this structure. */
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| struct vhost_poll {
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| 	poll_table		table;
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| 	wait_queue_head_t	*wqh;
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| 	wait_queue_entry_t	wait;
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| 	struct vhost_work	work;
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| 	__poll_t		mask;
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| 	struct vhost_dev	*dev;
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| };
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| 
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| void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
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| void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
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| bool vhost_has_work(struct vhost_dev *dev);
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| 
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| void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
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| 		     __poll_t mask, struct vhost_dev *dev);
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| int vhost_poll_start(struct vhost_poll *poll, struct file *file);
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| void vhost_poll_stop(struct vhost_poll *poll);
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| void vhost_poll_queue(struct vhost_poll *poll);
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| void vhost_dev_flush(struct vhost_dev *dev);
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| 
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| struct vhost_log {
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| 	u64 addr;
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| 	u64 len;
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| };
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| 
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| enum vhost_uaddr_type {
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| 	VHOST_ADDR_DESC = 0,
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| 	VHOST_ADDR_AVAIL = 1,
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| 	VHOST_ADDR_USED = 2,
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| 	VHOST_NUM_ADDRS = 3,
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| };
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| 
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| struct vhost_vring_call {
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| 	struct eventfd_ctx *ctx;
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| 	struct irq_bypass_producer producer;
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| };
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| 
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| /* The virtqueue structure describes a queue attached to a device. */
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| struct vhost_virtqueue {
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| 	struct vhost_dev *dev;
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| 
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| 	/* The actual ring of buffers. */
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| 	struct mutex mutex;
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| 	unsigned int num;
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| 	vring_desc_t __user *desc;
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| 	vring_avail_t __user *avail;
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| 	vring_used_t __user *used;
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| 	const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
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| 	struct file *kick;
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| 	struct vhost_vring_call call_ctx;
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| 	struct eventfd_ctx *error_ctx;
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| 	struct eventfd_ctx *log_ctx;
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| 
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| 	struct vhost_poll poll;
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| 
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| 	/* The routine to call when the Guest pings us, or timeout. */
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| 	vhost_work_fn_t handle_kick;
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| 
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| 	/* Last available index we saw.
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| 	 * Values are limited to 0x7fff, and the high bit is used as
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| 	 * a wrap counter when using VIRTIO_F_RING_PACKED. */
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| 	u16 last_avail_idx;
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| 
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| 	/* Caches available index value from user. */
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| 	u16 avail_idx;
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| 
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| 	/* Last index we used.
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| 	 * Values are limited to 0x7fff, and the high bit is used as
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| 	 * a wrap counter when using VIRTIO_F_RING_PACKED. */
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| 	u16 last_used_idx;
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| 
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| 	/* Used flags */
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| 	u16 used_flags;
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| 
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| 	/* Last used index value we have signalled on */
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| 	u16 signalled_used;
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| 
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| 	/* Last used index value we have signalled on */
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| 	bool signalled_used_valid;
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| 
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| 	/* Log writes to used structure. */
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| 	bool log_used;
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| 	u64 log_addr;
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| 
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| 	struct iovec iov[UIO_MAXIOV];
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| 	struct iovec iotlb_iov[64];
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| 	struct iovec *indirect;
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| 	struct vring_used_elem *heads;
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| 	/* Protected by virtqueue mutex. */
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| 	struct vhost_iotlb *umem;
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| 	struct vhost_iotlb *iotlb;
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| 	void *private_data;
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| 	u64 acked_features;
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| 	u64 acked_backend_features;
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| 	/* Log write descriptors */
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| 	void __user *log_base;
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| 	struct vhost_log *log;
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| 	struct iovec log_iov[64];
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| 
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| 	/* Ring endianness. Defaults to legacy native endianness.
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| 	 * Set to true when starting a modern virtio device. */
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| 	bool is_le;
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| #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
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| 	/* Ring endianness requested by userspace for cross-endian support. */
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| 	bool user_be;
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| #endif
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| 	u32 busyloop_timeout;
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| };
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| 
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| struct vhost_msg_node {
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|   union {
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| 	  struct vhost_msg msg;
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| 	  struct vhost_msg_v2 msg_v2;
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|   };
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|   struct vhost_virtqueue *vq;
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|   struct list_head node;
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| };
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| 
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| struct vhost_dev {
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| 	struct mm_struct *mm;
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| 	struct mutex mutex;
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| 	struct vhost_virtqueue **vqs;
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| 	int nvqs;
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| 	struct eventfd_ctx *log_ctx;
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| 	struct vhost_worker *worker;
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| 	struct vhost_iotlb *umem;
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| 	struct vhost_iotlb *iotlb;
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| 	spinlock_t iotlb_lock;
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| 	struct list_head read_list;
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| 	struct list_head pending_list;
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| 	wait_queue_head_t wait;
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| 	int iov_limit;
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| 	int weight;
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| 	int byte_weight;
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| 	bool use_worker;
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| 	int (*msg_handler)(struct vhost_dev *dev, u32 asid,
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| 			   struct vhost_iotlb_msg *msg);
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| };
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| 
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| bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
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| void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
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| 		    int nvqs, int iov_limit, int weight, int byte_weight,
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| 		    bool use_worker,
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| 		    int (*msg_handler)(struct vhost_dev *dev, u32 asid,
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| 				       struct vhost_iotlb_msg *msg));
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| long vhost_dev_set_owner(struct vhost_dev *dev);
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| bool vhost_dev_has_owner(struct vhost_dev *dev);
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| long vhost_dev_check_owner(struct vhost_dev *);
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| struct vhost_iotlb *vhost_dev_reset_owner_prepare(void);
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| void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb);
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| void vhost_dev_cleanup(struct vhost_dev *);
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| void vhost_dev_stop(struct vhost_dev *);
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| long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
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| long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
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| bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
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| bool vhost_log_access_ok(struct vhost_dev *);
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| void vhost_clear_msg(struct vhost_dev *dev);
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| 
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| int vhost_get_vq_desc(struct vhost_virtqueue *,
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| 		      struct iovec iov[], unsigned int iov_size,
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| 		      unsigned int *out_num, unsigned int *in_num,
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| 		      struct vhost_log *log, unsigned int *log_num);
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| void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
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| 
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| bool vhost_vq_is_setup(struct vhost_virtqueue *vq);
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| int vhost_vq_init_access(struct vhost_virtqueue *);
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| int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
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| int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
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| 		     unsigned count);
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| void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
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| 			       unsigned int id, int len);
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| void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
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| 			       struct vring_used_elem *heads, unsigned count);
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| void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
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| void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
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| bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
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| bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
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| 
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| int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
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| 		    unsigned int log_num, u64 len,
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| 		    struct iovec *iov, int count);
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| int vq_meta_prefetch(struct vhost_virtqueue *vq);
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| 
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| struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
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| void vhost_enqueue_msg(struct vhost_dev *dev,
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| 		       struct list_head *head,
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| 		       struct vhost_msg_node *node);
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| struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
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| 					 struct list_head *head);
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| void vhost_set_backend_features(struct vhost_dev *dev, u64 features);
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| 
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| __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev,
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| 			    poll_table *wait);
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| ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
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| 			    int noblock);
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| ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
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| 			     struct iov_iter *from);
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| int vhost_init_device_iotlb(struct vhost_dev *d);
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| 
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| void vhost_iotlb_map_free(struct vhost_iotlb *iotlb,
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| 			  struct vhost_iotlb_map *map);
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| 
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| #define vq_err(vq, fmt, ...) do {                                  \
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| 		pr_debug(pr_fmt(fmt), ##__VA_ARGS__);       \
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| 		if ((vq)->error_ctx)                               \
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| 				eventfd_signal((vq)->error_ctx);\
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| 	} while (0)
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| 
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| enum {
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| 	VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
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| 			 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
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| 			 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
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| 			 (1ULL << VHOST_F_LOG_ALL) |
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| 			 (1ULL << VIRTIO_F_ANY_LAYOUT) |
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| 			 (1ULL << VIRTIO_F_VERSION_1)
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| };
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| 
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| /**
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|  * vhost_vq_set_backend - Set backend.
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|  *
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|  * @vq            Virtqueue.
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|  * @private_data  The private data.
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|  *
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|  * Context: Need to call with vq->mutex acquired.
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|  */
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| static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq,
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| 					void *private_data)
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| {
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| 	vq->private_data = private_data;
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| }
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| 
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| /**
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|  * vhost_vq_get_backend - Get backend.
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|  *
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|  * @vq            Virtqueue.
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|  *
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|  * Context: Need to call with vq->mutex acquired.
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|  * Return: Private data previously set with vhost_vq_set_backend.
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|  */
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| static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq)
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| {
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| 	return vq->private_data;
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| }
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| 
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| static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
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| {
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| 	return vq->acked_features & (1ULL << bit);
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| }
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| 
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| static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit)
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| {
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| 	return vq->acked_backend_features & (1ULL << bit);
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| }
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| 
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| #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
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| static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
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| {
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| 	return vq->is_le;
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| }
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| #else
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| static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
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| {
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| 	return virtio_legacy_is_little_endian() || vq->is_le;
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| }
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| #endif
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| 
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| /* Memory accessors */
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| static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
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| {
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| 	return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
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| }
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| 
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| static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
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| {
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| 	return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
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| }
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| 
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| static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
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| {
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| 	return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
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| }
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| 
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| static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
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| {
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| 	return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
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| }
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| 
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| static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
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| {
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| 	return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
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| }
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| 
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| static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
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| {
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| 	return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
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| }
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| #endif
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