mirror of
https://github.com/torvalds/linux.git
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3652117f85
Ever since the eventfd type was introduced back in 2007 in commit
e1ad7468c7 ("signal/timer/event: eventfd core") the eventfd_signal()
function only ever passed 1 as a value for @n. There's no point in
keeping that additional argument.
Link: https://lore.kernel.org/r/20231122-vfs-eventfd-signal-v2-2-bd549b14ce0c@kernel.org
Acked-by: Xu Yilun <yilun.xu@intel.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com> # ocxl
Acked-by: Eric Farman <farman@linux.ibm.com> # s390
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
343 lines
10 KiB
C
343 lines
10 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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#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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struct vhost_work;
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struct vhost_task;
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typedef void (*vhost_work_fn_t)(struct vhost_work *work);
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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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struct vhost_worker {
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struct vhost_task *vtsk;
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/* Used to serialize device wide flushing with worker swapping. */
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struct mutex mutex;
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struct llist_head work_list;
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u64 kcov_handle;
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u32 id;
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int attachment_cnt;
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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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struct vhost_virtqueue *vq;
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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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struct vhost_virtqueue *vq);
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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_work_init(struct vhost_work *work, vhost_work_fn_t fn);
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void vhost_dev_flush(struct vhost_dev *dev);
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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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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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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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/* 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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struct vhost_worker __rcu *worker;
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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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struct vhost_poll poll;
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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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/* 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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/* Caches available index value from user. */
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u16 avail_idx;
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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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/* Used flags */
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u16 used_flags;
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/* Last used index value we have signalled on */
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u16 signalled_used;
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/* Last used index value we have signalled on */
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bool signalled_used_valid;
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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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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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/* 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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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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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_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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struct xarray worker_xa;
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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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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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long vhost_worker_ioctl(struct vhost_dev *dev, unsigned int ioctl,
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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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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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void vhost_vq_flush(struct vhost_virtqueue *vq);
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bool vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work);
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bool vhost_vq_has_work(struct vhost_virtqueue *vq);
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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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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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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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__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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void vhost_iotlb_map_free(struct vhost_iotlb *iotlb,
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struct vhost_iotlb_map *map);
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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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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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* 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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* 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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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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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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#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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/* 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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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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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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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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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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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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