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 15 struct vhost_device; 16 17 struct vhost_work; 18 typedef void (*vhost_work_fn_t)(struct vhost_work *work); 19 20 struct vhost_work { 21 struct list_head node; 22 vhost_work_fn_t fn; 23 wait_queue_head_t done; 24 int flushing; 25 unsigned queue_seq; 26 unsigned done_seq; 27 }; 28 29 /* Poll a file (eventfd or socket) */ 30 /* Note: there's nothing vhost specific about this structure. */ 31 struct 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 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); 42 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); 49 void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work); 50 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp); 51 52 struct vhost_log { 53 u64 addr; 54 u64 len; 55 }; 56 57 struct vhost_virtqueue; 58 59 /* The virtqueue structure describes a queue attached to a device. */ 60 struct vhost_virtqueue { 61 struct vhost_dev *dev; 62 63 /* The actual ring of buffers. */ 64 struct mutex mutex; 65 unsigned int num; 66 struct vring_desc __user *desc; 67 struct vring_avail __user *avail; 68 struct vring_used __user *used; 69 struct file *kick; 70 struct file *call; 71 struct file *error; 72 struct eventfd_ctx *call_ctx; 73 struct eventfd_ctx *error_ctx; 74 struct eventfd_ctx *log_ctx; 75 76 struct vhost_poll poll; 77 78 /* The routine to call when the Guest pings us, or timeout. */ 79 vhost_work_fn_t handle_kick; 80 81 /* Last available index we saw. */ 82 u16 last_avail_idx; 83 84 /* Caches available index value from user. */ 85 u16 avail_idx; 86 87 /* Last index we used. */ 88 u16 last_used_idx; 89 90 /* Used flags */ 91 u16 used_flags; 92 93 /* Last used index value we have signalled on */ 94 u16 signalled_used; 95 96 /* Last used index value we have signalled on */ 97 bool signalled_used_valid; 98 99 /* Log writes to used structure. */ 100 bool log_used; 101 u64 log_addr; 102 103 struct iovec iov[UIO_MAXIOV]; 104 struct iovec *indirect; 105 struct vring_used_elem *heads; 106 /* Protected by virtqueue mutex. */ 107 void *private_data; 108 /* Log write descriptors */ 109 void __user *log_base; 110 struct vhost_log *log; 111 }; 112 113 struct vhost_dev { 114 /* Readers use RCU to access memory table pointer 115 * log base pointer and features. 116 * Writers use mutex below.*/ 117 struct vhost_memory __rcu *memory; 118 struct mm_struct *mm; 119 struct mutex mutex; 120 unsigned acked_features; 121 struct vhost_virtqueue **vqs; 122 int nvqs; 123 struct file *log_file; 124 struct eventfd_ctx *log_ctx; 125 spinlock_t work_lock; 126 struct list_head work_list; 127 struct task_struct *worker; 128 }; 129 130 long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs); 131 long vhost_dev_set_owner(struct vhost_dev *dev); 132 bool vhost_dev_has_owner(struct vhost_dev *dev); 133 long vhost_dev_check_owner(struct vhost_dev *); 134 struct vhost_memory *vhost_dev_reset_owner_prepare(void); 135 void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *); 136 void vhost_dev_cleanup(struct vhost_dev *, bool locked); 137 void vhost_dev_stop(struct vhost_dev *); 138 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 139 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp); 140 int vhost_vq_access_ok(struct vhost_virtqueue *vq); 141 int vhost_log_access_ok(struct vhost_dev *); 142 143 int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *, 144 struct iovec iov[], unsigned int iov_count, 145 unsigned int *out_num, unsigned int *in_num, 146 struct vhost_log *log, unsigned int *log_num); 147 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); 148 149 int vhost_init_used(struct vhost_virtqueue *); 150 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 151 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 152 unsigned count); 153 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 154 unsigned int id, int len); 155 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 156 struct vring_used_elem *heads, unsigned count); 157 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 158 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 159 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 160 161 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 162 unsigned int log_num, u64 len); 163 164 #define vq_err(vq, fmt, ...) do { \ 165 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 166 if ((vq)->error_ctx) \ 167 eventfd_signal((vq)->error_ctx, 1);\ 168 } while (0) 169 170 enum { 171 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 172 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | 173 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 174 (1ULL << VHOST_F_LOG_ALL), 175 }; 176 177 static inline int vhost_has_feature(struct vhost_dev *dev, int bit) 178 { 179 unsigned acked_features; 180 181 /* TODO: check that we are running from vhost_worker or dev mutex is 182 * held? */ 183 acked_features = rcu_dereference_index_check(dev->acked_features, 1); 184 return acked_features & (1 << bit); 185 } 186 #endif 187