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>
18 typedef void (*vhost_work_fn_t)(struct vhost_work *work);
21 struct list_head node;
23 wait_queue_head_t done;
29 /* Poll a file (eventfd or socket) */
30 /* Note: there's nothing vhost specific about this structure. */
33 wait_queue_head_t *wqh;
35 struct vhost_work work;
37 struct vhost_dev *dev;
40 void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
41 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
43 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
44 unsigned long mask, struct vhost_dev *dev);
45 int vhost_poll_start(struct vhost_poll *poll, struct file *file);
46 void vhost_poll_stop(struct vhost_poll *poll);
47 void vhost_poll_flush(struct vhost_poll *poll);
48 void vhost_poll_queue(struct vhost_poll *poll);
55 struct vhost_virtqueue;
57 /* The virtqueue structure describes a queue attached to a device. */
58 struct vhost_virtqueue {
59 struct vhost_dev *dev;
61 /* The actual ring of buffers. */
64 struct vring_desc __user *desc;
65 struct vring_avail __user *avail;
66 struct vring_used __user *used;
70 struct eventfd_ctx *call_ctx;
71 struct eventfd_ctx *error_ctx;
72 struct eventfd_ctx *log_ctx;
74 struct vhost_poll poll;
76 /* The routine to call when the Guest pings us, or timeout. */
77 vhost_work_fn_t handle_kick;
79 /* Last available index we saw. */
82 /* Caches available index value from user. */
85 /* Last index we used. */
91 /* Last used index value we have signalled on */
94 /* Last used index value we have signalled on */
95 bool signalled_used_valid;
97 /* Log writes to used structure. */
101 struct iovec iov[UIO_MAXIOV];
102 /* hdr is used to store the virtio header.
103 * Since each iovec has >= 1 byte length, we never need more than
104 * header length entries to store the header. */
105 struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
106 struct iovec *indirect;
109 struct vring_used_elem *heads;
110 /* We use a kind of RCU to access private pointer.
111 * All readers access it from worker, which makes it possible to
112 * flush the vhost_work instead of synchronize_rcu. Therefore readers do
113 * not need to call rcu_read_lock/rcu_read_unlock: the beginning of
114 * vhost_work execution acts instead of rcu_read_lock() and the end of
115 * vhost_work execution acts instead of rcu_read_unlock().
116 * Writers use virtqueue mutex. */
117 void __rcu *private_data;
118 /* Log write descriptors */
119 void __user *log_base;
120 struct vhost_log *log;
124 /* Readers use RCU to access memory table pointer
125 * log base pointer and features.
126 * Writers use mutex below.*/
127 struct vhost_memory __rcu *memory;
128 struct mm_struct *mm;
130 unsigned acked_features;
131 struct vhost_virtqueue **vqs;
133 struct file *log_file;
134 struct eventfd_ctx *log_ctx;
135 spinlock_t work_lock;
136 struct list_head work_list;
137 struct task_struct *worker;
140 long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
141 long vhost_dev_check_owner(struct vhost_dev *);
142 long vhost_dev_reset_owner(struct vhost_dev *);
143 void vhost_dev_cleanup(struct vhost_dev *, bool locked);
144 void vhost_dev_stop(struct vhost_dev *);
145 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
146 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
147 int vhost_vq_access_ok(struct vhost_virtqueue *vq);
148 int vhost_log_access_ok(struct vhost_dev *);
150 int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *,
151 struct iovec iov[], unsigned int iov_count,
152 unsigned int *out_num, unsigned int *in_num,
153 struct vhost_log *log, unsigned int *log_num);
154 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
156 int vhost_init_used(struct vhost_virtqueue *);
157 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
158 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
160 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
161 unsigned int id, int len);
162 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
163 struct vring_used_elem *heads, unsigned count);
164 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
165 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
166 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
168 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
169 unsigned int log_num, u64 len);
171 #define vq_err(vq, fmt, ...) do { \
172 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
173 if ((vq)->error_ctx) \
174 eventfd_signal((vq)->error_ctx, 1);\
178 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
179 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
180 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
181 (1ULL << VHOST_F_LOG_ALL),
182 VHOST_NET_FEATURES = VHOST_FEATURES |
183 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
184 (1ULL << VIRTIO_NET_F_MRG_RXBUF),
187 static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
189 unsigned acked_features;
191 /* TODO: check that we are running from vhost_worker or dev mutex is
193 acked_features = rcu_dereference_index_check(dev->acked_features, 1);
194 return acked_features & (1 << bit);
197 void vhost_enable_zcopy(int vq);