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1 | #ifndef _VHOST_H | |
2 | #define _VHOST_H | |
3 | ||
4 | #include <linux/eventfd.h> | |
5 | #include <linux/vhost.h> | |
6 | #include <linux/mm.h> | |
7 | #include <linux/mutex.h> | |
8 | #include <linux/poll.h> | |
9 | #include <linux/file.h> | |
10 | #include <linux/skbuff.h> | |
11 | #include <linux/uio.h> | |
12 | #include <linux/virtio_config.h> | |
13 | #include <linux/virtio_ring.h> | |
14 | #include <asm/atomic.h> | |
15 | ||
16 | struct vhost_device; | |
17 | ||
18 | enum { | |
19 | /* Enough place for all fragments, head, and virtio net header. */ | |
20 | VHOST_NET_MAX_SG = MAX_SKB_FRAGS + 2, | |
21 | }; | |
22 | ||
23 | struct vhost_work; | |
24 | typedef void (*vhost_work_fn_t)(struct vhost_work *work); | |
25 | ||
26 | struct vhost_work { | |
27 | struct list_head node; | |
28 | vhost_work_fn_t fn; | |
29 | wait_queue_head_t done; | |
30 | int flushing; | |
31 | unsigned queue_seq; | |
32 | unsigned done_seq; | |
33 | }; | |
34 | ||
35 | /* Poll a file (eventfd or socket) */ | |
36 | /* Note: there's nothing vhost specific about this structure. */ | |
37 | struct vhost_poll { | |
38 | poll_table table; | |
39 | wait_queue_head_t *wqh; | |
40 | wait_queue_t wait; | |
41 | struct vhost_work work; | |
42 | unsigned long mask; | |
43 | struct vhost_dev *dev; | |
44 | }; | |
45 | ||
46 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, | |
47 | unsigned long mask, struct vhost_dev *dev); | |
48 | void vhost_poll_start(struct vhost_poll *poll, struct file *file); | |
49 | void vhost_poll_stop(struct vhost_poll *poll); | |
50 | void vhost_poll_flush(struct vhost_poll *poll); | |
51 | void vhost_poll_queue(struct vhost_poll *poll); | |
52 | ||
53 | struct vhost_log { | |
54 | u64 addr; | |
55 | u64 len; | |
56 | }; | |
57 | ||
58 | /* The virtqueue structure describes a queue attached to a device. */ | |
59 | struct vhost_virtqueue { | |
60 | struct vhost_dev *dev; | |
61 | ||
62 | /* The actual ring of buffers. */ | |
63 | struct mutex mutex; | |
64 | unsigned int num; | |
65 | struct vring_desc __user *desc; | |
66 | struct vring_avail __user *avail; | |
67 | struct vring_used __user *used; | |
68 | struct file *kick; | |
69 | struct file *call; | |
70 | struct file *error; | |
71 | struct eventfd_ctx *call_ctx; | |
72 | struct eventfd_ctx *error_ctx; | |
73 | struct eventfd_ctx *log_ctx; | |
74 | ||
75 | struct vhost_poll poll; | |
76 | ||
77 | /* The routine to call when the Guest pings us, or timeout. */ | |
78 | vhost_work_fn_t handle_kick; | |
79 | ||
80 | /* Last available index we saw. */ | |
81 | u16 last_avail_idx; | |
82 | ||
83 | /* Caches available index value from user. */ | |
84 | u16 avail_idx; | |
85 | ||
86 | /* Last index we used. */ | |
87 | u16 last_used_idx; | |
88 | ||
89 | /* Used flags */ | |
90 | u16 used_flags; | |
91 | ||
92 | /* Log writes to used structure. */ | |
93 | bool log_used; | |
94 | u64 log_addr; | |
95 | ||
96 | struct iovec indirect[VHOST_NET_MAX_SG]; | |
97 | struct iovec iov[VHOST_NET_MAX_SG]; | |
98 | struct iovec hdr[VHOST_NET_MAX_SG]; | |
99 | size_t hdr_size; | |
100 | /* We use a kind of RCU to access private pointer. | |
101 | * All readers access it from worker, which makes it possible to | |
102 | * flush the vhost_work instead of synchronize_rcu. Therefore readers do | |
103 | * not need to call rcu_read_lock/rcu_read_unlock: the beginning of | |
104 | * vhost_work execution acts instead of rcu_read_lock() and the end of | |
105 | * vhost_work execution acts instead of rcu_read_lock(). | |
106 | * Writers use virtqueue mutex. */ | |
107 | void *private_data; | |
108 | /* Log write descriptors */ | |
109 | void __user *log_base; | |
110 | struct vhost_log log[VHOST_NET_MAX_SG]; | |
111 | }; | |
112 | ||
113 | struct vhost_dev { | |
114 | /* Readers use RCU to access memory table pointer | |
115 | * log base pointer and features. | |
116 | * Writers use mutex below.*/ | |
117 | struct vhost_memory *memory; | |
118 | struct mm_struct *mm; | |
119 | struct mutex mutex; | |
120 | unsigned acked_features; | |
121 | struct vhost_virtqueue *vqs; | |
122 | int nvqs; | |
123 | struct file *log_file; | |
124 | struct eventfd_ctx *log_ctx; | |
125 | spinlock_t work_lock; | |
126 | struct list_head work_list; | |
127 | struct task_struct *worker; | |
128 | }; | |
129 | ||
130 | long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs); | |
131 | long vhost_dev_check_owner(struct vhost_dev *); | |
132 | long vhost_dev_reset_owner(struct vhost_dev *); | |
133 | void vhost_dev_cleanup(struct vhost_dev *); | |
134 | long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg); | |
135 | int vhost_vq_access_ok(struct vhost_virtqueue *vq); | |
136 | int vhost_log_access_ok(struct vhost_dev *); | |
137 | ||
138 | int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *, | |
139 | struct iovec iov[], unsigned int iov_count, | |
140 | unsigned int *out_num, unsigned int *in_num, | |
141 | struct vhost_log *log, unsigned int *log_num); | |
142 | void vhost_discard_vq_desc(struct vhost_virtqueue *); | |
143 | ||
144 | int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); | |
145 | void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); | |
146 | void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, | |
147 | unsigned int head, int len); | |
148 | void vhost_disable_notify(struct vhost_virtqueue *); | |
149 | bool vhost_enable_notify(struct vhost_virtqueue *); | |
150 | ||
151 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, | |
152 | unsigned int log_num, u64 len); | |
153 | ||
154 | #define vq_err(vq, fmt, ...) do { \ | |
155 | pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ | |
156 | if ((vq)->error_ctx) \ | |
157 | eventfd_signal((vq)->error_ctx, 1);\ | |
158 | } while (0) | |
159 | ||
160 | enum { | |
161 | VHOST_FEATURES = (1 << VIRTIO_F_NOTIFY_ON_EMPTY) | | |
162 | (1 << VIRTIO_RING_F_INDIRECT_DESC) | | |
163 | (1 << VHOST_F_LOG_ALL) | | |
164 | (1 << VHOST_NET_F_VIRTIO_NET_HDR), | |
165 | }; | |
166 | ||
167 | static inline int vhost_has_feature(struct vhost_dev *dev, int bit) | |
168 | { | |
169 | unsigned acked_features = rcu_dereference(dev->acked_features); | |
170 | return acked_features & (1 << bit); | |
171 | } | |
172 | ||
173 | #endif |