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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> | |
10 | #include <linux/skbuff.h> | |
11 | #include <linux/uio.h> | |
12 | #include <linux/virtio_config.h> | |
13 | #include <linux/virtio_ring.h> | |
c23f3445 | 14 | #include <asm/atomic.h> |
3a4d5c94 MT |
15 | |
16 | struct vhost_device; | |
17 | ||
c23f3445 TH |
18 | struct vhost_work; |
19 | typedef void (*vhost_work_fn_t)(struct vhost_work *work); | |
20 | ||
21 | struct vhost_work { | |
22 | struct list_head node; | |
23 | vhost_work_fn_t fn; | |
24 | wait_queue_head_t done; | |
25 | int flushing; | |
26 | unsigned queue_seq; | |
27 | unsigned done_seq; | |
28 | }; | |
29 | ||
3a4d5c94 MT |
30 | /* Poll a file (eventfd or socket) */ |
31 | /* Note: there's nothing vhost specific about this structure. */ | |
32 | struct vhost_poll { | |
33 | poll_table table; | |
34 | wait_queue_head_t *wqh; | |
35 | wait_queue_t wait; | |
c23f3445 | 36 | struct vhost_work work; |
3a4d5c94 | 37 | unsigned long mask; |
c23f3445 | 38 | struct vhost_dev *dev; |
3a4d5c94 MT |
39 | }; |
40 | ||
c23f3445 TH |
41 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
42 | unsigned long mask, struct vhost_dev *dev); | |
3a4d5c94 MT |
43 | void vhost_poll_start(struct vhost_poll *poll, struct file *file); |
44 | void vhost_poll_stop(struct vhost_poll *poll); | |
45 | void vhost_poll_flush(struct vhost_poll *poll); | |
46 | void vhost_poll_queue(struct vhost_poll *poll); | |
47 | ||
48 | struct vhost_log { | |
49 | u64 addr; | |
50 | u64 len; | |
51 | }; | |
52 | ||
53 | /* The virtqueue structure describes a queue attached to a device. */ | |
54 | struct vhost_virtqueue { | |
55 | struct vhost_dev *dev; | |
56 | ||
57 | /* The actual ring of buffers. */ | |
58 | struct mutex mutex; | |
59 | unsigned int num; | |
60 | struct vring_desc __user *desc; | |
61 | struct vring_avail __user *avail; | |
62 | struct vring_used __user *used; | |
63 | struct file *kick; | |
64 | struct file *call; | |
65 | struct file *error; | |
66 | struct eventfd_ctx *call_ctx; | |
67 | struct eventfd_ctx *error_ctx; | |
68 | struct eventfd_ctx *log_ctx; | |
69 | ||
70 | struct vhost_poll poll; | |
71 | ||
72 | /* The routine to call when the Guest pings us, or timeout. */ | |
c23f3445 | 73 | vhost_work_fn_t handle_kick; |
3a4d5c94 MT |
74 | |
75 | /* Last available index we saw. */ | |
76 | u16 last_avail_idx; | |
77 | ||
78 | /* Caches available index value from user. */ | |
79 | u16 avail_idx; | |
80 | ||
81 | /* Last index we used. */ | |
82 | u16 last_used_idx; | |
83 | ||
84 | /* Used flags */ | |
85 | u16 used_flags; | |
86 | ||
87 | /* Log writes to used structure. */ | |
88 | bool log_used; | |
89 | u64 log_addr; | |
90 | ||
e0e9b406 JW |
91 | struct iovec iov[UIO_MAXIOV]; |
92 | /* hdr is used to store the virtio header. | |
93 | * Since each iovec has >= 1 byte length, we never need more than | |
94 | * header length entries to store the header. */ | |
95 | struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)]; | |
96 | struct iovec *indirect; | |
8dd014ad DS |
97 | size_t vhost_hlen; |
98 | size_t sock_hlen; | |
e0e9b406 | 99 | struct vring_used_elem *heads; |
3a4d5c94 | 100 | /* We use a kind of RCU to access private pointer. |
c23f3445 TH |
101 | * All readers access it from worker, which makes it possible to |
102 | * flush the vhost_work instead of synchronize_rcu. Therefore readers do | |
3a4d5c94 | 103 | * not need to call rcu_read_lock/rcu_read_unlock: the beginning of |
c23f3445 | 104 | * vhost_work execution acts instead of rcu_read_lock() and the end of |
a290aec8 | 105 | * vhost_work execution acts instead of rcu_read_unlock(). |
3a4d5c94 | 106 | * Writers use virtqueue mutex. */ |
28457ee6 | 107 | void __rcu *private_data; |
3a4d5c94 MT |
108 | /* Log write descriptors */ |
109 | void __user *log_base; | |
e0e9b406 | 110 | struct vhost_log *log; |
3a4d5c94 MT |
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.*/ | |
28457ee6 | 117 | struct vhost_memory __rcu *memory; |
3a4d5c94 MT |
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; | |
c23f3445 TH |
125 | spinlock_t work_lock; |
126 | struct list_head work_list; | |
127 | struct task_struct *worker; | |
3a4d5c94 MT |
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 | ||
d5675bd2 MT |
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); | |
8dd014ad | 142 | void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); |
3a4d5c94 MT |
143 | |
144 | int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); | |
8dd014ad DS |
145 | int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, |
146 | unsigned count); | |
3a4d5c94 | 147 | void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, |
8dd014ad DS |
148 | unsigned int id, int len); |
149 | void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, | |
150 | struct vring_used_elem *heads, unsigned count); | |
151 | void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); | |
3a4d5c94 MT |
152 | void vhost_disable_notify(struct vhost_virtqueue *); |
153 | bool vhost_enable_notify(struct vhost_virtqueue *); | |
154 | ||
155 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, | |
156 | unsigned int log_num, u64 len); | |
157 | ||
3a4d5c94 MT |
158 | #define vq_err(vq, fmt, ...) do { \ |
159 | pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ | |
160 | if ((vq)->error_ctx) \ | |
161 | eventfd_signal((vq)->error_ctx, 1);\ | |
162 | } while (0) | |
163 | ||
164 | enum { | |
165 | VHOST_FEATURES = (1 << VIRTIO_F_NOTIFY_ON_EMPTY) | | |
166 | (1 << VIRTIO_RING_F_INDIRECT_DESC) | | |
167 | (1 << VHOST_F_LOG_ALL) | | |
8dd014ad DS |
168 | (1 << VHOST_NET_F_VIRTIO_NET_HDR) | |
169 | (1 << VIRTIO_NET_F_MRG_RXBUF), | |
3a4d5c94 MT |
170 | }; |
171 | ||
172 | static inline int vhost_has_feature(struct vhost_dev *dev, int bit) | |
173 | { | |
28457ee6 AB |
174 | unsigned acked_features; |
175 | ||
5e18247b MT |
176 | /* TODO: check that we are running from vhost_worker or dev mutex is |
177 | * held? */ | |
178 | acked_features = rcu_dereference_index_check(dev->acked_features, 1); | |
3a4d5c94 MT |
179 | return acked_features & (1 << bit); |
180 | } | |
181 | ||
182 | #endif |