forked from Minki/linux
429711aec2
We use to have message like:
struct vhost_msg {
int type;
union {
struct vhost_iotlb_msg iotlb;
__u8 padding[64];
};
};
Unfortunately, there will be a hole of 32bit in 64bit machine because
of the alignment. This leads a different formats between 32bit API and
64bit API. What's more it will break 32bit program running on 64bit
machine.
So fixing this by introducing a new message type with an explicit
32bit reserved field after type like:
struct vhost_msg_v2 {
__u32 type;
__u32 reserved;
union {
struct vhost_iotlb_msg iotlb;
__u8 padding[64];
};
};
We will have a consistent ABI after switching to use this. To enable
this capability, introduce a new ioctl (VHOST_SET_BAKCEND_FEATURE) for
userspace to enable this feature (VHOST_BACKEND_F_IOTLB_V2).
Fixes: 6b1e6cc785 ("vhost: new device IOTLB API")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
293 lines
8.4 KiB
C
293 lines
8.4 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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struct vhost_work;
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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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/* 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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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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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_flush(struct vhost_poll *poll);
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void vhost_poll_queue(struct vhost_poll *poll);
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void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
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long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
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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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#define START(node) ((node)->start)
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#define LAST(node) ((node)->last)
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struct vhost_umem_node {
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struct rb_node rb;
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struct list_head link;
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__u64 start;
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__u64 last;
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__u64 size;
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__u64 userspace_addr;
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__u32 perm;
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__u32 flags_padding;
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__u64 __subtree_last;
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};
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struct vhost_umem {
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struct rb_root_cached umem_tree;
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struct list_head umem_list;
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int numem;
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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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/* 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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/* The actual ring of buffers. */
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struct mutex mutex;
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unsigned int num;
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struct vring_desc __user *desc;
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struct vring_avail __user *avail;
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struct vring_used __user *used;
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const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
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struct file *kick;
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struct eventfd_ctx *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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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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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_umem *umem;
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struct vhost_umem *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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/* 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 llist_head work_list;
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struct task_struct *worker;
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struct vhost_umem *umem;
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struct vhost_umem *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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};
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void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
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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_umem *vhost_dev_reset_owner_prepare(void);
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void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
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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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int vhost_get_vq_desc(struct vhost_virtqueue *,
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struct iovec iov[], unsigned int iov_count,
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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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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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int vq_iotlb_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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__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, bool enabled);
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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, 1);\
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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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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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