4 #include <linux/eventfd.h>
5 #include <linux/vhost.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>
16 typedef void (*vhost_work_fn_t)(struct vhost_work *work);
19 struct list_head node;
21 wait_queue_head_t done;
27 /* Poll a file (eventfd or socket) */
28 /* Note: there's nothing vhost specific about this structure. */
31 wait_queue_head_t *wqh;
33 struct vhost_work work;
35 struct vhost_dev *dev;
38 void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
39 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
41 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
42 unsigned long mask, struct vhost_dev *dev);
43 int 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 void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
48 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
55 /* The virtqueue structure describes a queue attached to a device. */
56 struct vhost_virtqueue {
57 struct vhost_dev *dev;
59 /* The actual ring of buffers. */
62 struct vring_desc __user *desc;
63 struct vring_avail __user *avail;
64 struct vring_used __user *used;
68 struct eventfd_ctx *call_ctx;
69 struct eventfd_ctx *error_ctx;
70 struct eventfd_ctx *log_ctx;
72 struct vhost_poll poll;
74 /* The routine to call when the Guest pings us, or timeout. */
75 vhost_work_fn_t handle_kick;
77 /* Last available index we saw. */
80 /* Caches available index value from user. */
83 /* Last index we used. */
89 /* Last used index value we have signalled on */
92 /* Last used index value we have signalled on */
93 bool signalled_used_valid;
95 /* Log writes to used structure. */
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;
106 /* Log write descriptors */
107 void __user *log_base;
108 struct vhost_log *log;
112 struct vhost_memory *memory;
113 struct mm_struct *mm;
115 struct vhost_virtqueue **vqs;
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;
124 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
125 long vhost_dev_set_owner(struct vhost_dev *dev);
126 bool vhost_dev_has_owner(struct vhost_dev *dev);
127 long vhost_dev_check_owner(struct vhost_dev *);
128 struct vhost_memory *vhost_dev_reset_owner_prepare(void);
129 void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *);
130 void vhost_dev_cleanup(struct vhost_dev *, bool locked);
131 void vhost_dev_stop(struct vhost_dev *);
132 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
133 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
134 int vhost_vq_access_ok(struct vhost_virtqueue *vq);
135 int vhost_log_access_ok(struct vhost_dev *);
137 int 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);
141 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
143 int vhost_init_used(struct vhost_virtqueue *);
144 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
145 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
147 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
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 *);
152 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
153 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
155 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
156 unsigned int log_num, u64 len);
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);\
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),
171 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
173 return vq->acked_features & (1ULL << bit);
176 /* Memory accessors */
177 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
179 return __virtio16_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
182 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
184 return __cpu_to_virtio16(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
187 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
189 return __virtio32_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
192 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
194 return __cpu_to_virtio32(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
197 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
199 return __virtio64_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
202 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
204 return __cpu_to_virtio64(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);