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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 <linux/atomic.h>
15
16/* This is for zerocopy, used buffer len is set to 1 when lower device DMA
17 * done */
18#define VHOST_DMA_DONE_LEN 1
19#define VHOST_DMA_CLEAR_LEN 0
20
21struct vhost_device;
22
23struct vhost_work;
24typedef void (*vhost_work_fn_t)(struct vhost_work *work);
25
26struct 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. */
37struct 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
46void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
47 unsigned long mask, struct vhost_dev *dev);
48void vhost_poll_start(struct vhost_poll *poll, struct file *file);
49void vhost_poll_stop(struct vhost_poll *poll);
50void vhost_poll_flush(struct vhost_poll *poll);
51void vhost_poll_queue(struct vhost_poll *poll);
52
53struct vhost_log {
54 u64 addr;
55 u64 len;
56};
57
58struct vhost_virtqueue;
59
60struct vhost_ubuf_ref {
61 struct kref kref;
62 wait_queue_head_t wait;
63 struct vhost_virtqueue *vq;
64};
65
66struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *, bool zcopy);
67void vhost_ubuf_put(struct vhost_ubuf_ref *);
68void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *);
69
70/* The virtqueue structure describes a queue attached to a device. */
71struct vhost_virtqueue {
72 struct vhost_dev *dev;
73
74 /* The actual ring of buffers. */
75 struct mutex mutex;
76 unsigned int num;
77 struct vring_desc __user *desc;
78 struct vring_avail __user *avail;
79 struct vring_used __user *used;
80 struct file *kick;
81 struct file *call;
82 struct file *error;
83 struct eventfd_ctx *call_ctx;
84 struct eventfd_ctx *error_ctx;
85 struct eventfd_ctx *log_ctx;
86
87 struct vhost_poll poll;
88
89 /* The routine to call when the Guest pings us, or timeout. */
90 vhost_work_fn_t handle_kick;
91
92 /* Last available index we saw. */
93 u16 last_avail_idx;
94
95 /* Caches available index value from user. */
96 u16 avail_idx;
97
98 /* Last index we used. */
99 u16 last_used_idx;
100
101 /* Used flags */
102 u16 used_flags;
103
104 /* Last used index value we have signalled on */
105 u16 signalled_used;
106
107 /* Last used index value we have signalled on */
108 bool signalled_used_valid;
109
110 /* Log writes to used structure. */
111 bool log_used;
112 u64 log_addr;
113
114 struct iovec iov[UIO_MAXIOV];
115 /* hdr is used to store the virtio header.
116 * Since each iovec has >= 1 byte length, we never need more than
117 * header length entries to store the header. */
118 struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
119 struct iovec *indirect;
120 size_t vhost_hlen;
121 size_t sock_hlen;
122 struct vring_used_elem *heads;
123 /* We use a kind of RCU to access private pointer.
124 * All readers access it from worker, which makes it possible to
125 * flush the vhost_work instead of synchronize_rcu. Therefore readers do
126 * not need to call rcu_read_lock/rcu_read_unlock: the beginning of
127 * vhost_work execution acts instead of rcu_read_lock() and the end of
128 * vhost_work execution acts instead of rcu_read_unlock().
129 * Writers use virtqueue mutex. */
130 void __rcu *private_data;
131 /* Log write descriptors */
132 void __user *log_base;
133 struct vhost_log *log;
134 /* vhost zerocopy support fields below: */
135 /* last used idx for outstanding DMA zerocopy buffers */
136 int upend_idx;
137 /* first used idx for DMA done zerocopy buffers */
138 int done_idx;
139 /* an array of userspace buffers info */
140 struct ubuf_info *ubuf_info;
141 /* Reference counting for outstanding ubufs.
142 * Protected by vq mutex. Writers must also take device mutex. */
143 struct vhost_ubuf_ref *ubufs;
144};
145
146struct vhost_dev {
147 /* Readers use RCU to access memory table pointer
148 * log base pointer and features.
149 * Writers use mutex below.*/
150 struct vhost_memory __rcu *memory;
151 struct mm_struct *mm;
152 struct mutex mutex;
153 unsigned acked_features;
154 struct vhost_virtqueue *vqs;
155 int nvqs;
156 struct file *log_file;
157 struct eventfd_ctx *log_ctx;
158 spinlock_t work_lock;
159 struct list_head work_list;
160 struct task_struct *worker;
161};
162
163long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
164long vhost_dev_check_owner(struct vhost_dev *);
165long vhost_dev_reset_owner(struct vhost_dev *);
166void vhost_dev_cleanup(struct vhost_dev *);
167long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg);
168int vhost_vq_access_ok(struct vhost_virtqueue *vq);
169int vhost_log_access_ok(struct vhost_dev *);
170
171int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *,
172 struct iovec iov[], unsigned int iov_count,
173 unsigned int *out_num, unsigned int *in_num,
174 struct vhost_log *log, unsigned int *log_num);
175void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
176
177int vhost_init_used(struct vhost_virtqueue *);
178int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
179int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
180 unsigned count);
181void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
182 unsigned int id, int len);
183void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
184 struct vring_used_elem *heads, unsigned count);
185void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
186void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
187bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
188
189int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
190 unsigned int log_num, u64 len);
191void vhost_zerocopy_callback(void *arg);
192int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq);
193
194#define vq_err(vq, fmt, ...) do { \
195 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
196 if ((vq)->error_ctx) \
197 eventfd_signal((vq)->error_ctx, 1);\
198 } while (0)
199
200enum {
201 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
202 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
203 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
204 (1ULL << VHOST_F_LOG_ALL) |
205 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
206 (1ULL << VIRTIO_NET_F_MRG_RXBUF),
207};
208
209static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
210{
211 unsigned acked_features;
212
213 /* TODO: check that we are running from vhost_worker or dev mutex is
214 * held? */
215 acked_features = rcu_dereference_index_check(dev->acked_features, 1);
216 return acked_features & (1 << bit);
217}
218
219void vhost_enable_zcopy(int vq);
220
221#endif
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/uio.h>
11#include <linux/virtio_config.h>
12#include <linux/virtio_ring.h>
13#include <linux/atomic.h>
14
15struct vhost_work;
16typedef void (*vhost_work_fn_t)(struct vhost_work *work);
17
18#define VHOST_WORK_QUEUED 1
19struct vhost_work {
20 struct llist_node node;
21 vhost_work_fn_t fn;
22 wait_queue_head_t done;
23 int flushing;
24 unsigned queue_seq;
25 unsigned done_seq;
26 unsigned long flags;
27};
28
29/* Poll a file (eventfd or socket) */
30/* Note: there's nothing vhost specific about this structure. */
31struct vhost_poll {
32 poll_table table;
33 wait_queue_head_t *wqh;
34 wait_queue_t wait;
35 struct vhost_work work;
36 unsigned long mask;
37 struct vhost_dev *dev;
38};
39
40void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
41void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
42bool vhost_has_work(struct vhost_dev *dev);
43
44void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
45 unsigned long mask, struct vhost_dev *dev);
46int vhost_poll_start(struct vhost_poll *poll, struct file *file);
47void vhost_poll_stop(struct vhost_poll *poll);
48void vhost_poll_flush(struct vhost_poll *poll);
49void vhost_poll_queue(struct vhost_poll *poll);
50void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
51long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
52
53struct vhost_log {
54 u64 addr;
55 u64 len;
56};
57
58#define START(node) ((node)->start)
59#define LAST(node) ((node)->last)
60
61struct vhost_umem_node {
62 struct rb_node rb;
63 struct list_head link;
64 __u64 start;
65 __u64 last;
66 __u64 size;
67 __u64 userspace_addr;
68 __u32 perm;
69 __u32 flags_padding;
70 __u64 __subtree_last;
71};
72
73struct vhost_umem {
74 struct rb_root umem_tree;
75 struct list_head umem_list;
76 int numem;
77};
78
79/* The virtqueue structure describes a queue attached to a device. */
80struct vhost_virtqueue {
81 struct vhost_dev *dev;
82
83 /* The actual ring of buffers. */
84 struct mutex mutex;
85 unsigned int num;
86 struct vring_desc __user *desc;
87 struct vring_avail __user *avail;
88 struct vring_used __user *used;
89 struct file *kick;
90 struct file *call;
91 struct file *error;
92 struct eventfd_ctx *call_ctx;
93 struct eventfd_ctx *error_ctx;
94 struct eventfd_ctx *log_ctx;
95
96 struct vhost_poll poll;
97
98 /* The routine to call when the Guest pings us, or timeout. */
99 vhost_work_fn_t handle_kick;
100
101 /* Last available index we saw. */
102 u16 last_avail_idx;
103
104 /* Caches available index value from user. */
105 u16 avail_idx;
106
107 /* Last index we used. */
108 u16 last_used_idx;
109
110 /* Last used evet we've seen */
111 u16 last_used_event;
112
113 /* Used flags */
114 u16 used_flags;
115
116 /* Last used index value we have signalled on */
117 u16 signalled_used;
118
119 /* Last used index value we have signalled on */
120 bool signalled_used_valid;
121
122 /* Log writes to used structure. */
123 bool log_used;
124 u64 log_addr;
125
126 struct iovec iov[UIO_MAXIOV];
127 struct iovec iotlb_iov[64];
128 struct iovec *indirect;
129 struct vring_used_elem *heads;
130 /* Protected by virtqueue mutex. */
131 struct vhost_umem *umem;
132 struct vhost_umem *iotlb;
133 void *private_data;
134 u64 acked_features;
135 /* Log write descriptors */
136 void __user *log_base;
137 struct vhost_log *log;
138
139 /* Ring endianness. Defaults to legacy native endianness.
140 * Set to true when starting a modern virtio device. */
141 bool is_le;
142#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
143 /* Ring endianness requested by userspace for cross-endian support. */
144 bool user_be;
145#endif
146 u32 busyloop_timeout;
147};
148
149struct vhost_msg_node {
150 struct vhost_msg msg;
151 struct vhost_virtqueue *vq;
152 struct list_head node;
153};
154
155struct vhost_dev {
156 struct mm_struct *mm;
157 struct mutex mutex;
158 struct vhost_virtqueue **vqs;
159 int nvqs;
160 struct file *log_file;
161 struct eventfd_ctx *log_ctx;
162 struct llist_head work_list;
163 struct task_struct *worker;
164 struct vhost_umem *umem;
165 struct vhost_umem *iotlb;
166 spinlock_t iotlb_lock;
167 struct list_head read_list;
168 struct list_head pending_list;
169 wait_queue_head_t wait;
170};
171
172void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
173long vhost_dev_set_owner(struct vhost_dev *dev);
174bool vhost_dev_has_owner(struct vhost_dev *dev);
175long vhost_dev_check_owner(struct vhost_dev *);
176struct vhost_umem *vhost_dev_reset_owner_prepare(void);
177void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
178void vhost_dev_cleanup(struct vhost_dev *, bool locked);
179void vhost_dev_stop(struct vhost_dev *);
180long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
181long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
182int vhost_vq_access_ok(struct vhost_virtqueue *vq);
183int vhost_log_access_ok(struct vhost_dev *);
184
185int vhost_get_vq_desc(struct vhost_virtqueue *,
186 struct iovec iov[], unsigned int iov_count,
187 unsigned int *out_num, unsigned int *in_num,
188 struct vhost_log *log, unsigned int *log_num);
189void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
190
191int vhost_vq_init_access(struct vhost_virtqueue *);
192int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
193int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
194 unsigned count);
195void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
196 unsigned int id, int len);
197void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
198 struct vring_used_elem *heads, unsigned count);
199void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
200void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
201bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
202bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
203
204int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
205 unsigned int log_num, u64 len);
206int vq_iotlb_prefetch(struct vhost_virtqueue *vq);
207
208struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
209void vhost_enqueue_msg(struct vhost_dev *dev,
210 struct list_head *head,
211 struct vhost_msg_node *node);
212struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
213 struct list_head *head);
214unsigned int vhost_chr_poll(struct file *file, struct vhost_dev *dev,
215 poll_table *wait);
216ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
217 int noblock);
218ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
219 struct iov_iter *from);
220int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);
221
222#define vq_err(vq, fmt, ...) do { \
223 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
224 if ((vq)->error_ctx) \
225 eventfd_signal((vq)->error_ctx, 1);\
226 } while (0)
227
228enum {
229 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
230 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
231 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
232 (1ULL << VHOST_F_LOG_ALL) |
233 (1ULL << VIRTIO_F_ANY_LAYOUT) |
234 (1ULL << VIRTIO_F_VERSION_1)
235};
236
237static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
238{
239 return vq->acked_features & (1ULL << bit);
240}
241
242#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
243static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
244{
245 return vq->is_le;
246}
247#else
248static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
249{
250 return virtio_legacy_is_little_endian() || vq->is_le;
251}
252#endif
253
254/* Memory accessors */
255static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
256{
257 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
258}
259
260static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
261{
262 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
263}
264
265static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
266{
267 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
268}
269
270static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
271{
272 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
273}
274
275static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
276{
277 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
278}
279
280static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
281{
282 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
283}
284#endif