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
18struct vhost_work {
19	struct list_head	  node;
20	vhost_work_fn_t		  fn;
21	wait_queue_head_t	  done;
22	int			  flushing;
23	unsigned		  queue_seq;
24	unsigned		  done_seq;
25};
26
27/* Poll a file (eventfd or socket) */
28/* Note: there's nothing vhost specific about this structure. */
29struct vhost_poll {
30	poll_table                table;
31	wait_queue_head_t        *wqh;
32	wait_queue_t              wait;
33	struct vhost_work	  work;
34	unsigned long		  mask;
35	struct vhost_dev	 *dev;
36};
37
38void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
39void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
40
41void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
42		     unsigned long mask, struct vhost_dev *dev);
43int vhost_poll_start(struct vhost_poll *poll, struct file *file);
44void vhost_poll_stop(struct vhost_poll *poll);
45void vhost_poll_flush(struct vhost_poll *poll);
46void vhost_poll_queue(struct vhost_poll *poll);
47void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
48long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
49
50struct vhost_log {
51	u64 addr;
52	u64 len;
53};
54
55/* The virtqueue structure describes a queue attached to a device. */
56struct vhost_virtqueue {
57	struct vhost_dev *dev;
58
59	/* The actual ring of buffers. */
60	struct mutex mutex;
61	unsigned int num;
62	struct vring_desc __user *desc;
63	struct vring_avail __user *avail;
64	struct vring_used __user *used;
65	struct file *kick;
66	struct file *call;
67	struct file *error;
68	struct eventfd_ctx *call_ctx;
69	struct eventfd_ctx *error_ctx;
70	struct eventfd_ctx *log_ctx;
71
72	struct vhost_poll poll;
73
74	/* The routine to call when the Guest pings us, or timeout. */
75	vhost_work_fn_t handle_kick;
76
77	/* Last available index we saw. */
78	u16 last_avail_idx;
79
80	/* Caches available index value from user. */
81	u16 avail_idx;
82
83	/* Last index we used. */
84	u16 last_used_idx;
85
86	/* Used flags */
87	u16 used_flags;
88
89	/* Last used index value we have signalled on */
90	u16 signalled_used;
91
92	/* Last used index value we have signalled on */
93	bool signalled_used_valid;
94
95	/* Log writes to used structure. */
96	bool log_used;
97	u64 log_addr;
98
99	struct iovec iov[UIO_MAXIOV];
100	struct iovec *indirect;
101	struct vring_used_elem *heads;
102	/* Protected by virtqueue mutex. */
103	struct vhost_memory *memory;
104	void *private_data;
105	u64 acked_features;
106	/* Log write descriptors */
107	void __user *log_base;
108	struct vhost_log *log;
109};
110
111struct vhost_dev {
112	struct vhost_memory *memory;
113	struct mm_struct *mm;
114	struct mutex mutex;
115	struct vhost_virtqueue **vqs;
116	int nvqs;
117	struct file *log_file;
118	struct eventfd_ctx *log_ctx;
119	spinlock_t work_lock;
120	struct list_head work_list;
121	struct task_struct *worker;
122};
123
124void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
125long vhost_dev_set_owner(struct vhost_dev *dev);
126bool vhost_dev_has_owner(struct vhost_dev *dev);
127long vhost_dev_check_owner(struct vhost_dev *);
128struct vhost_memory *vhost_dev_reset_owner_prepare(void);
129void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *);
130void vhost_dev_cleanup(struct vhost_dev *, bool locked);
131void vhost_dev_stop(struct vhost_dev *);
132long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
133long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
134int vhost_vq_access_ok(struct vhost_virtqueue *vq);
135int vhost_log_access_ok(struct vhost_dev *);
136
137int vhost_get_vq_desc(struct vhost_virtqueue *,
138		      struct iovec iov[], unsigned int iov_count,
139		      unsigned int *out_num, unsigned int *in_num,
140		      struct vhost_log *log, unsigned int *log_num);
141void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
142
143int vhost_init_used(struct vhost_virtqueue *);
144int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
145int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
146		     unsigned count);
147void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
148			       unsigned int id, int len);
149void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
150			       struct vring_used_elem *heads, unsigned count);
151void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
152void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
153bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
154
155int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
156		    unsigned int log_num, u64 len);
157
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
164enum {
165	VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
166			 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
167			 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
168			 (1ULL << VHOST_F_LOG_ALL),
169};
170
171static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
172{
173	return vq->acked_features & (1ULL << bit);
174}
175
176/* Memory accessors */
177static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
178{
179	return __virtio16_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
180}
181
182static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
183{
184	return __cpu_to_virtio16(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
185}
186
187static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
188{
189	return __virtio32_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
190}
191
192static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
193{
194	return __cpu_to_virtio32(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
195}
196
197static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
198{
199	return __virtio64_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
200}
201
202static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
203{
204	return __cpu_to_virtio64(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
205}
206#endif
207