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3a4d5c94 MT |
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> | |
3a4d5c94 MT |
8 | #include <linux/poll.h> |
9 | #include <linux/file.h> | |
3a4d5c94 MT |
10 | #include <linux/uio.h> |
11 | #include <linux/virtio_config.h> | |
12 | #include <linux/virtio_ring.h> | |
60063497 | 13 | #include <linux/atomic.h> |
3a4d5c94 MT |
14 | |
15 | struct vhost_device; | |
16 | ||
c23f3445 TH |
17 | struct vhost_work; |
18 | typedef void (*vhost_work_fn_t)(struct vhost_work *work); | |
19 | ||
20 | struct vhost_work { | |
21 | struct list_head node; | |
22 | vhost_work_fn_t fn; | |
23 | wait_queue_head_t done; | |
24 | int flushing; | |
25 | unsigned queue_seq; | |
26 | unsigned done_seq; | |
27 | }; | |
28 | ||
3a4d5c94 MT |
29 | /* Poll a file (eventfd or socket) */ |
30 | /* Note: there's nothing vhost specific about this structure. */ | |
31 | struct vhost_poll { | |
32 | poll_table table; | |
33 | wait_queue_head_t *wqh; | |
34 | wait_queue_t wait; | |
c23f3445 | 35 | struct vhost_work work; |
3a4d5c94 | 36 | unsigned long mask; |
c23f3445 | 37 | struct vhost_dev *dev; |
3a4d5c94 MT |
38 | }; |
39 | ||
163049ae SH |
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); | |
42 | ||
c23f3445 TH |
43 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
44 | unsigned long mask, struct vhost_dev *dev); | |
2b8b328b | 45 | int vhost_poll_start(struct vhost_poll *poll, struct file *file); |
3a4d5c94 MT |
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); | |
49 | ||
50 | struct vhost_log { | |
51 | u64 addr; | |
52 | u64 len; | |
53 | }; | |
54 | ||
bab632d6 MT |
55 | struct vhost_virtqueue; |
56 | ||
3a4d5c94 MT |
57 | /* The virtqueue structure describes a queue attached to a device. */ |
58 | struct vhost_virtqueue { | |
59 | struct vhost_dev *dev; | |
60 | ||
61 | /* The actual ring of buffers. */ | |
62 | struct mutex mutex; | |
63 | unsigned int num; | |
64 | struct vring_desc __user *desc; | |
65 | struct vring_avail __user *avail; | |
66 | struct vring_used __user *used; | |
67 | struct file *kick; | |
68 | struct file *call; | |
69 | struct file *error; | |
70 | struct eventfd_ctx *call_ctx; | |
71 | struct eventfd_ctx *error_ctx; | |
72 | struct eventfd_ctx *log_ctx; | |
73 | ||
74 | struct vhost_poll poll; | |
75 | ||
76 | /* The routine to call when the Guest pings us, or timeout. */ | |
c23f3445 | 77 | vhost_work_fn_t handle_kick; |
3a4d5c94 MT |
78 | |
79 | /* Last available index we saw. */ | |
80 | u16 last_avail_idx; | |
81 | ||
82 | /* Caches available index value from user. */ | |
83 | u16 avail_idx; | |
84 | ||
85 | /* Last index we used. */ | |
86 | u16 last_used_idx; | |
87 | ||
88 | /* Used flags */ | |
89 | u16 used_flags; | |
90 | ||
8ea8cf89 MT |
91 | /* Last used index value we have signalled on */ |
92 | u16 signalled_used; | |
93 | ||
94 | /* Last used index value we have signalled on */ | |
95 | bool signalled_used_valid; | |
96 | ||
3a4d5c94 MT |
97 | /* Log writes to used structure. */ |
98 | bool log_used; | |
99 | u64 log_addr; | |
100 | ||
e0e9b406 | 101 | struct iovec iov[UIO_MAXIOV]; |
e0e9b406 | 102 | struct iovec *indirect; |
e0e9b406 | 103 | struct vring_used_elem *heads; |
3a4d5c94 | 104 | /* We use a kind of RCU to access private pointer. |
c23f3445 TH |
105 | * All readers access it from worker, which makes it possible to |
106 | * flush the vhost_work instead of synchronize_rcu. Therefore readers do | |
3a4d5c94 | 107 | * not need to call rcu_read_lock/rcu_read_unlock: the beginning of |
c23f3445 | 108 | * vhost_work execution acts instead of rcu_read_lock() and the end of |
a290aec8 | 109 | * vhost_work execution acts instead of rcu_read_unlock(). |
3a4d5c94 | 110 | * Writers use virtqueue mutex. */ |
28457ee6 | 111 | void __rcu *private_data; |
3a4d5c94 MT |
112 | /* Log write descriptors */ |
113 | void __user *log_base; | |
e0e9b406 | 114 | struct vhost_log *log; |
3a4d5c94 MT |
115 | }; |
116 | ||
117 | struct vhost_dev { | |
118 | /* Readers use RCU to access memory table pointer | |
119 | * log base pointer and features. | |
120 | * Writers use mutex below.*/ | |
28457ee6 | 121 | struct vhost_memory __rcu *memory; |
3a4d5c94 MT |
122 | struct mm_struct *mm; |
123 | struct mutex mutex; | |
124 | unsigned acked_features; | |
3ab2e420 | 125 | struct vhost_virtqueue **vqs; |
3a4d5c94 MT |
126 | int nvqs; |
127 | struct file *log_file; | |
128 | struct eventfd_ctx *log_ctx; | |
c23f3445 TH |
129 | spinlock_t work_lock; |
130 | struct list_head work_list; | |
131 | struct task_struct *worker; | |
3a4d5c94 MT |
132 | }; |
133 | ||
3ab2e420 | 134 | long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs); |
54db63c2 | 135 | long vhost_dev_set_owner(struct vhost_dev *dev); |
05c05351 | 136 | bool vhost_dev_has_owner(struct vhost_dev *dev); |
3a4d5c94 | 137 | long vhost_dev_check_owner(struct vhost_dev *); |
150b9e51 MT |
138 | struct vhost_memory *vhost_dev_reset_owner_prepare(void); |
139 | void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *); | |
ea5d4046 | 140 | void vhost_dev_cleanup(struct vhost_dev *, bool locked); |
b211616d | 141 | void vhost_dev_stop(struct vhost_dev *); |
935cdee7 MT |
142 | long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); |
143 | long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp); | |
3a4d5c94 MT |
144 | int vhost_vq_access_ok(struct vhost_virtqueue *vq); |
145 | int vhost_log_access_ok(struct vhost_dev *); | |
146 | ||
d5675bd2 MT |
147 | int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *, |
148 | struct iovec iov[], unsigned int iov_count, | |
149 | unsigned int *out_num, unsigned int *in_num, | |
150 | struct vhost_log *log, unsigned int *log_num); | |
8dd014ad | 151 | void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); |
3a4d5c94 | 152 | |
f59281da | 153 | int vhost_init_used(struct vhost_virtqueue *); |
3a4d5c94 | 154 | int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); |
8dd014ad DS |
155 | int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, |
156 | unsigned count); | |
3a4d5c94 | 157 | void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, |
8dd014ad DS |
158 | unsigned int id, int len); |
159 | void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, | |
160 | struct vring_used_elem *heads, unsigned count); | |
161 | void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); | |
8ea8cf89 MT |
162 | void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); |
163 | bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); | |
3a4d5c94 MT |
164 | |
165 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, | |
166 | unsigned int log_num, u64 len); | |
167 | ||
3a4d5c94 MT |
168 | #define vq_err(vq, fmt, ...) do { \ |
169 | pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ | |
170 | if ((vq)->error_ctx) \ | |
171 | eventfd_signal((vq)->error_ctx, 1);\ | |
172 | } while (0) | |
173 | ||
174 | enum { | |
8ea8cf89 MT |
175 | VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | |
176 | (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | | |
177 | (1ULL << VIRTIO_RING_F_EVENT_IDX) | | |
0dd05a3b | 178 | (1ULL << VHOST_F_LOG_ALL), |
3a4d5c94 MT |
179 | }; |
180 | ||
181 | static inline int vhost_has_feature(struct vhost_dev *dev, int bit) | |
182 | { | |
28457ee6 AB |
183 | unsigned acked_features; |
184 | ||
5e18247b MT |
185 | /* TODO: check that we are running from vhost_worker or dev mutex is |
186 | * held? */ | |
187 | acked_features = rcu_dereference_index_check(dev->acked_features, 1); | |
3a4d5c94 MT |
188 | return acked_features & (1 << bit); |
189 | } | |
3a4d5c94 | 190 | #endif |