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800f879a AT |
1 | /* |
2 | This is the exact copy of linux-2.6.32-220.7.1.el6.x86_64/drivers/vhost/vhost.h | |
3 | except for this comment. | |
4 | */ | |
5 | #ifndef _VHOST_H | |
6 | #define _VHOST_H | |
7 | ||
8 | #include <linux/eventfd.h> | |
9 | #ifdef RHEL_RELEASE_CODE | |
10 | #include <linux/vhost.h> | |
11 | #else | |
12 | #include "./linux/vhost.h" | |
13 | #endif | |
14 | #include <linux/mm.h> | |
15 | #include <linux/mutex.h> | |
16 | #include <linux/poll.h> | |
17 | #include <linux/file.h> | |
18 | #include <linux/skbuff.h> | |
19 | #include <linux/uio.h> | |
20 | #include <linux/virtio_config.h> | |
21 | #include <linux/virtio_ring.h> | |
22 | #include <asm/atomic.h> | |
23 | ||
24 | /* This is for zerocopy, used buffer len is set to 1 when lower device DMA | |
25 | * done */ | |
26 | #define VHOST_DMA_DONE_LEN 1 | |
27 | #define VHOST_DMA_CLEAR_LEN 0 | |
28 | ||
29 | struct vhost_device; | |
30 | ||
31 | struct vhost_work; | |
32 | typedef void (*vhost_work_fn_t)(struct vhost_work *work); | |
33 | ||
34 | struct vhost_work { | |
c3839907 AT |
35 | struct list_head node; |
36 | vhost_work_fn_t fn; | |
37 | wait_queue_head_t done; | |
38 | int flushing; | |
39 | unsigned queue_seq; | |
40 | unsigned done_seq; | |
800f879a AT |
41 | }; |
42 | ||
43 | /* Poll a file (eventfd or socket) */ | |
44 | /* Note: there's nothing vhost specific about this structure. */ | |
45 | struct vhost_poll { | |
c3839907 AT |
46 | poll_table table; |
47 | wait_queue_head_t *wqh; | |
48 | wait_queue_entry_t wait; | |
49 | struct vhost_work work; | |
50 | unsigned long mask; | |
51 | struct vhost_dev *dev; | |
800f879a AT |
52 | }; |
53 | ||
54 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, | |
55 | unsigned long mask, struct vhost_dev *dev); | |
56 | void vhost_poll_start(struct vhost_poll *poll, struct file *file); | |
57 | void vhost_poll_stop(struct vhost_poll *poll); | |
58 | void vhost_poll_flush(struct vhost_poll *poll); | |
59 | void vhost_poll_queue(struct vhost_poll *poll); | |
60 | ||
61 | struct vhost_log { | |
62 | u64 addr; | |
63 | u64 len; | |
64 | }; | |
65 | ||
66 | struct vhost_virtqueue; | |
67 | ||
68 | struct vhost_ubuf_ref { | |
69 | struct kref kref; | |
70 | wait_queue_head_t wait; | |
71 | struct vhost_virtqueue *vq; | |
72 | }; | |
73 | ||
74 | struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *, bool zcopy); | |
75 | void vhost_ubuf_put(struct vhost_ubuf_ref *); | |
76 | void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *); | |
77 | ||
78 | /* The virtqueue structure describes a queue attached to a device. */ | |
79 | struct vhost_virtqueue { | |
80 | struct vhost_dev *dev; | |
81 | ||
82 | /* The actual ring of buffers. */ | |
83 | struct mutex mutex; | |
84 | unsigned int num; | |
85 | struct vring_desc __user *desc; | |
86 | struct vring_avail __user *avail; | |
87 | struct vring_used __user *used; | |
88 | struct file *kick; | |
89 | struct file *call; | |
90 | struct file *error; | |
91 | struct eventfd_ctx *call_ctx; | |
92 | struct eventfd_ctx *error_ctx; | |
93 | struct eventfd_ctx *log_ctx; | |
94 | ||
95 | struct vhost_poll poll; | |
96 | ||
97 | /* The routine to call when the Guest pings us, or timeout. */ | |
98 | vhost_work_fn_t handle_kick; | |
99 | ||
100 | /* Last available index we saw. */ | |
101 | u16 last_avail_idx; | |
102 | ||
103 | /* Caches available index value from user. */ | |
104 | u16 avail_idx; | |
105 | ||
106 | /* Last index we used. */ | |
107 | u16 last_used_idx; | |
108 | ||
109 | /* Used flags */ | |
110 | u16 used_flags; | |
111 | ||
112 | /* Last used index value we have signalled on */ | |
113 | u16 signalled_used; | |
114 | ||
115 | /* Last used index value we have signalled on */ | |
116 | bool signalled_used_valid; | |
117 | ||
118 | /* Log writes to used structure. */ | |
119 | bool log_used; | |
120 | u64 log_addr; | |
121 | ||
122 | struct iovec iov[UIO_MAXIOV]; | |
123 | /* hdr is used to store the virtio header. | |
124 | * Since each iovec has >= 1 byte length, we never need more than | |
125 | * header length entries to store the header. */ | |
126 | struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)]; | |
127 | struct iovec *indirect; | |
128 | size_t vhost_hlen; | |
129 | size_t sock_hlen; | |
130 | struct vring_used_elem *heads; | |
131 | /* We use a kind of RCU to access private pointer. | |
132 | * All readers access it from worker, which makes it possible to | |
133 | * flush the vhost_work instead of synchronize_rcu. Therefore readers do | |
134 | * not need to call rcu_read_lock/rcu_read_unlock: the beginning of | |
135 | * vhost_work execution acts instead of rcu_read_lock() and the end of | |
136 | * vhost_work execution acts instead of rcu_read_lock(). | |
137 | * Writers use virtqueue mutex. */ | |
138 | void *private_data; | |
139 | /* Log write descriptors */ | |
140 | void __user *log_base; | |
141 | struct vhost_log *log; | |
142 | /* vhost zerocopy support fields below: */ | |
143 | /* last used idx for outstanding DMA zerocopy buffers */ | |
144 | int upend_idx; | |
145 | /* first used idx for DMA done zerocopy buffers */ | |
146 | int done_idx; | |
147 | /* an array of userspace buffers info */ | |
148 | struct ubuf_info *ubuf_info; | |
149 | /* Reference counting for outstanding ubufs. | |
150 | * Protected by vq mutex. Writers must also take device mutex. */ | |
151 | struct vhost_ubuf_ref *ubufs; | |
152 | }; | |
153 | ||
154 | struct vhost_dev { | |
155 | /* Readers use RCU to access memory table pointer | |
156 | * log base pointer and features. | |
157 | * Writers use mutex below.*/ | |
158 | struct vhost_memory *memory; | |
159 | struct mm_struct *mm; | |
160 | struct mutex mutex; | |
161 | unsigned acked_features; | |
162 | struct vhost_virtqueue *vqs; | |
163 | int nvqs; | |
164 | struct file *log_file; | |
165 | struct eventfd_ctx *log_ctx; | |
166 | spinlock_t work_lock; | |
167 | struct list_head work_list; | |
168 | struct task_struct *worker; | |
169 | }; | |
170 | ||
171 | long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs); | |
172 | long vhost_dev_check_owner(struct vhost_dev *); | |
173 | long vhost_dev_reset_owner(struct vhost_dev *); | |
174 | void vhost_dev_cleanup(struct vhost_dev *); | |
175 | long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg); | |
176 | int vhost_vq_access_ok(struct vhost_virtqueue *vq); | |
177 | int vhost_log_access_ok(struct vhost_dev *); | |
178 | ||
179 | int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *, | |
180 | struct iovec iov[], unsigned int iov_count, | |
181 | unsigned int *out_num, unsigned int *in_num, | |
182 | struct vhost_log *log, unsigned int *log_num); | |
183 | void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); | |
184 | ||
185 | int vhost_init_used(struct vhost_virtqueue *); | |
186 | int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); | |
187 | int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, | |
188 | unsigned count); | |
189 | void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, | |
190 | unsigned int id, int len); | |
191 | void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, | |
192 | struct vring_used_elem *heads, unsigned count); | |
193 | void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); | |
194 | void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); | |
195 | bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); | |
196 | ||
197 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, | |
198 | unsigned int log_num, u64 len); | |
199 | void vhost_zerocopy_callback(void *arg); | |
200 | int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq); | |
201 | ||
202 | #define vq_err(vq, fmt, ...) do { \ | |
203 | pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ | |
204 | if ((vq)->error_ctx) \ | |
205 | eventfd_signal((vq)->error_ctx, 1);\ | |
206 | } while (0) | |
207 | ||
208 | #ifndef __rcu_dereference_index_check | |
800f879a AT |
209 | #define __rcu_dereference_index_check(p, c) \ |
210 | ({ \ | |
5f16ba5a | 211 | typeof(p) _________p1 = READ_ONCE(p); \ |
800f879a AT |
212 | RCU_LOCKDEP_WARN(c, \ |
213 | "suspicious rcu_dereference_index_check()" \ | |
214 | " usage"); \ | |
215 | smp_read_barrier_depends(); \ | |
216 | (_________p1); \ | |
217 | }) | |
218 | #endif | |
800f879a AT |
219 | |
220 | enum { | |
221 | VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | | |
222 | (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | | |
223 | (1ULL << VIRTIO_RING_F_EVENT_IDX) | | |
224 | (1ULL << VHOST_F_LOG_ALL) | | |
225 | (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) | | |
226 | (1ULL << VIRTIO_NET_F_MRG_RXBUF), | |
227 | }; | |
228 | ||
229 | static inline int vhost_has_feature(struct vhost_dev *dev, int bit) | |
230 | { | |
231 | #ifdef RHEL_RELEASE_CODE | |
232 | #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0)) | |
233 | unsigned acked_features = rcu_dereference_index_check(dev->acked_features, rcu_read_lock_held()); | |
234 | #else | |
235 | unsigned acked_features = rcu_dereference(dev->acked_features); | |
236 | #endif | |
237 | #else | |
238 | #if (LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)) | |
239 | unsigned acked_features = rcu_dereference_index_check(dev->acked_features, rcu_read_lock_held()); | |
240 | #else | |
241 | unsigned acked_features = __rcu_dereference_index_check(dev->acked_features, rcu_read_lock_held()); | |
242 | #endif | |
243 | #endif | |
244 | return acked_features & (1 << bit); | |
245 | } | |
246 | ||
247 | void vhost_enable_zcopy(int vq); | |
248 | ||
249 | #endif |