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_work; 16 typedef void (*vhost_work_fn_t)(struct vhost_work *work); 17 18 struct 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. */ 29 struct 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 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); 40 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); 49 50 struct vhost_log { 51 u64 addr; 52 u64 len; 53 }; 54 55 /* The virtqueue structure describes a queue attached to a device. */ 56 struct 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 /* Ring endianness. Defaults to legacy native endianness. 111 * Set to true when starting a modern virtio device. */ 112 bool is_le; 113 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 114 /* Ring endianness requested by userspace for cross-endian support. */ 115 bool user_be; 116 #endif 117 }; 118 119 struct vhost_dev { 120 struct vhost_memory *memory; 121 struct mm_struct *mm; 122 struct mutex mutex; 123 struct vhost_virtqueue **vqs; 124 int nvqs; 125 struct file *log_file; 126 struct eventfd_ctx *log_ctx; 127 spinlock_t work_lock; 128 struct list_head work_list; 129 struct task_struct *worker; 130 }; 131 132 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs); 133 long vhost_dev_set_owner(struct vhost_dev *dev); 134 bool vhost_dev_has_owner(struct vhost_dev *dev); 135 long vhost_dev_check_owner(struct vhost_dev *); 136 struct vhost_memory *vhost_dev_reset_owner_prepare(void); 137 void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *); 138 void vhost_dev_cleanup(struct vhost_dev *, bool locked); 139 void vhost_dev_stop(struct vhost_dev *); 140 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 141 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp); 142 int vhost_vq_access_ok(struct vhost_virtqueue *vq); 143 int vhost_log_access_ok(struct vhost_dev *); 144 145 int vhost_get_vq_desc(struct vhost_virtqueue *, 146 struct iovec iov[], unsigned int iov_count, 147 unsigned int *out_num, unsigned int *in_num, 148 struct vhost_log *log, unsigned int *log_num); 149 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); 150 151 int vhost_init_used(struct vhost_virtqueue *); 152 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 153 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 154 unsigned count); 155 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 156 unsigned int id, int len); 157 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 158 struct vring_used_elem *heads, unsigned count); 159 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 160 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 161 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 162 163 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 164 unsigned int log_num, u64 len); 165 166 #define vq_err(vq, fmt, ...) do { \ 167 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 168 if ((vq)->error_ctx) \ 169 eventfd_signal((vq)->error_ctx, 1);\ 170 } while (0) 171 172 enum { 173 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 174 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | 175 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 176 (1ULL << VHOST_F_LOG_ALL), 177 }; 178 179 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 180 { 181 return vq->acked_features & (1ULL << bit); 182 } 183 184 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 185 { 186 return vq->is_le; 187 } 188 189 /* Memory accessors */ 190 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 191 { 192 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 193 } 194 195 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 196 { 197 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 198 } 199 200 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 201 { 202 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 203 } 204 205 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 206 { 207 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 208 } 209 210 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 211 { 212 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 213 } 214 215 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 216 { 217 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 218 } 219 #endif 220