4 #include <linux/eventfd.h>
5 #include <linux/vhost.h>
7 #include <linux/mutex.h>
8 #include <linux/poll.h>
9 #include <linux/file.h>
10 #include <linux/uio.h>
11 #include <linux/virtio_config.h>
12 #include <linux/virtio_ring.h>
13 #include <linux/atomic.h>
18 typedef void (*vhost_work_fn_t
)(struct vhost_work
*work
);
21 struct list_head node
;
23 wait_queue_head_t done
;
29 /* Poll a file (eventfd or socket) */
30 /* Note: there's nothing vhost specific about this structure. */
33 wait_queue_head_t
*wqh
;
35 struct vhost_work work
;
37 struct vhost_dev
*dev
;
40 void vhost_work_init(struct vhost_work
*work
, vhost_work_fn_t fn
);
41 void vhost_work_queue(struct vhost_dev
*dev
, struct vhost_work
*work
);
43 void vhost_poll_init(struct vhost_poll
*poll
, vhost_work_fn_t fn
,
44 unsigned long mask
, struct vhost_dev
*dev
);
45 int vhost_poll_start(struct vhost_poll
*poll
, struct file
*file
);
46 void vhost_poll_stop(struct vhost_poll
*poll
);
47 void vhost_poll_flush(struct vhost_poll
*poll
);
48 void vhost_poll_queue(struct vhost_poll
*poll
);
55 struct vhost_virtqueue
;
57 /* The virtqueue structure describes a queue attached to a device. */
58 struct vhost_virtqueue
{
59 struct vhost_dev
*dev
;
61 /* The actual ring of buffers. */
64 struct vring_desc __user
*desc
;
65 struct vring_avail __user
*avail
;
66 struct vring_used __user
*used
;
70 struct eventfd_ctx
*call_ctx
;
71 struct eventfd_ctx
*error_ctx
;
72 struct eventfd_ctx
*log_ctx
;
74 struct vhost_poll poll
;
76 /* The routine to call when the Guest pings us, or timeout. */
77 vhost_work_fn_t handle_kick
;
79 /* Last available index we saw. */
82 /* Caches available index value from user. */
85 /* Last index we used. */
91 /* Last used index value we have signalled on */
94 /* Last used index value we have signalled on */
95 bool signalled_used_valid
;
97 /* Log writes to used structure. */
101 struct iovec iov
[UIO_MAXIOV
];
102 struct iovec
*indirect
;
103 struct vring_used_elem
*heads
;
104 /* We use a kind of RCU to access private pointer.
105 * All readers access it from worker, which makes it possible to
106 * flush the vhost_work instead of synchronize_rcu. Therefore readers do
107 * not need to call rcu_read_lock/rcu_read_unlock: the beginning of
108 * vhost_work execution acts instead of rcu_read_lock() and the end of
109 * vhost_work execution acts instead of rcu_read_unlock().
110 * Writers use virtqueue mutex. */
111 void __rcu
*private_data
;
112 /* Log write descriptors */
113 void __user
*log_base
;
114 struct vhost_log
*log
;
118 /* Readers use RCU to access memory table pointer
119 * log base pointer and features.
120 * Writers use mutex below.*/
121 struct vhost_memory __rcu
*memory
;
122 struct mm_struct
*mm
;
124 unsigned acked_features
;
125 struct vhost_virtqueue
**vqs
;
127 struct file
*log_file
;
128 struct eventfd_ctx
*log_ctx
;
129 spinlock_t work_lock
;
130 struct list_head work_list
;
131 struct task_struct
*worker
;
134 long vhost_dev_init(struct vhost_dev
*, struct vhost_virtqueue
**vqs
, int nvqs
);
135 long vhost_dev_set_owner(struct vhost_dev
*dev
);
136 long vhost_dev_check_owner(struct vhost_dev
*);
137 struct vhost_memory
*vhost_dev_reset_owner_prepare(void);
138 void vhost_dev_reset_owner(struct vhost_dev
*, struct vhost_memory
*);
139 void vhost_dev_cleanup(struct vhost_dev
*, bool locked
);
140 void vhost_dev_stop(struct vhost_dev
*);
141 long vhost_dev_ioctl(struct vhost_dev
*, unsigned int ioctl
, void __user
*argp
);
142 long vhost_vring_ioctl(struct vhost_dev
*d
, int ioctl
, void __user
*argp
);
143 int vhost_vq_access_ok(struct vhost_virtqueue
*vq
);
144 int vhost_log_access_ok(struct vhost_dev
*);
146 int vhost_get_vq_desc(struct vhost_dev
*, struct vhost_virtqueue
*,
147 struct iovec iov
[], unsigned int iov_count
,
148 unsigned int *out_num
, unsigned int *in_num
,
149 struct vhost_log
*log
, unsigned int *log_num
);
150 void vhost_discard_vq_desc(struct vhost_virtqueue
*, int n
);
152 int vhost_init_used(struct vhost_virtqueue
*);
153 int vhost_add_used(struct vhost_virtqueue
*, unsigned int head
, int len
);
154 int vhost_add_used_n(struct vhost_virtqueue
*, struct vring_used_elem
*heads
,
156 void vhost_add_used_and_signal(struct vhost_dev
*, struct vhost_virtqueue
*,
157 unsigned int id
, int len
);
158 void vhost_add_used_and_signal_n(struct vhost_dev
*, struct vhost_virtqueue
*,
159 struct vring_used_elem
*heads
, unsigned count
);
160 void vhost_signal(struct vhost_dev
*, struct vhost_virtqueue
*);
161 void vhost_disable_notify(struct vhost_dev
*, struct vhost_virtqueue
*);
162 bool vhost_enable_notify(struct vhost_dev
*, struct vhost_virtqueue
*);
164 int vhost_log_write(struct vhost_virtqueue
*vq
, struct vhost_log
*log
,
165 unsigned int log_num
, u64 len
);
167 #define vq_err(vq, fmt, ...) do { \
168 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
169 if ((vq)->error_ctx) \
170 eventfd_signal((vq)->error_ctx, 1);\
174 VHOST_FEATURES
= (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY
) |
175 (1ULL << VIRTIO_RING_F_INDIRECT_DESC
) |
176 (1ULL << VIRTIO_RING_F_EVENT_IDX
) |
177 (1ULL << VHOST_F_LOG_ALL
),
180 static inline int vhost_has_feature(struct vhost_dev
*dev
, int bit
)
182 unsigned acked_features
;
184 /* TODO: check that we are running from vhost_worker or dev mutex is
186 acked_features
= rcu_dereference_index_check(dev
->acked_features
, 1);
187 return acked_features
& (1 << bit
);