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 #define VHOST_WORK_QUEUED 1 19 struct vhost_work { 20 struct llist_node node; 21 vhost_work_fn_t fn; 22 wait_queue_head_t done; 23 int flushing; 24 unsigned queue_seq; 25 unsigned done_seq; 26 unsigned long flags; 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 bool vhost_has_work(struct vhost_dev *dev); 43 44 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, 45 unsigned long mask, struct vhost_dev *dev); 46 int vhost_poll_start(struct vhost_poll *poll, struct file *file); 47 void vhost_poll_stop(struct vhost_poll *poll); 48 void vhost_poll_flush(struct vhost_poll *poll); 49 void vhost_poll_queue(struct vhost_poll *poll); 50 void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work); 51 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp); 52 53 struct vhost_log { 54 u64 addr; 55 u64 len; 56 }; 57 58 #define START(node) ((node)->start) 59 #define LAST(node) ((node)->last) 60 61 struct vhost_umem_node { 62 struct rb_node rb; 63 struct list_head link; 64 __u64 start; 65 __u64 last; 66 __u64 size; 67 __u64 userspace_addr; 68 __u32 perm; 69 __u32 flags_padding; 70 __u64 __subtree_last; 71 }; 72 73 struct vhost_umem { 74 struct rb_root umem_tree; 75 struct list_head umem_list; 76 int numem; 77 }; 78 79 enum vhost_uaddr_type { 80 VHOST_ADDR_DESC = 0, 81 VHOST_ADDR_AVAIL = 1, 82 VHOST_ADDR_USED = 2, 83 VHOST_NUM_ADDRS = 3, 84 }; 85 86 /* The virtqueue structure describes a queue attached to a device. */ 87 struct vhost_virtqueue { 88 struct vhost_dev *dev; 89 90 /* The actual ring of buffers. */ 91 struct mutex mutex; 92 unsigned int num; 93 struct vring_desc __user *desc; 94 struct vring_avail __user *avail; 95 struct vring_used __user *used; 96 const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS]; 97 struct file *kick; 98 struct file *call; 99 struct file *error; 100 struct eventfd_ctx *call_ctx; 101 struct eventfd_ctx *error_ctx; 102 struct eventfd_ctx *log_ctx; 103 104 struct vhost_poll poll; 105 106 /* The routine to call when the Guest pings us, or timeout. */ 107 vhost_work_fn_t handle_kick; 108 109 /* Last available index we saw. */ 110 u16 last_avail_idx; 111 112 /* Caches available index value from user. */ 113 u16 avail_idx; 114 115 /* Last index we used. */ 116 u16 last_used_idx; 117 118 /* Last used evet we've seen */ 119 u16 last_used_event; 120 121 /* Used flags */ 122 u16 used_flags; 123 124 /* Last used index value we have signalled on */ 125 u16 signalled_used; 126 127 /* Last used index value we have signalled on */ 128 bool signalled_used_valid; 129 130 /* Log writes to used structure. */ 131 bool log_used; 132 u64 log_addr; 133 134 struct iovec iov[UIO_MAXIOV]; 135 struct iovec iotlb_iov[64]; 136 struct iovec *indirect; 137 struct vring_used_elem *heads; 138 /* Protected by virtqueue mutex. */ 139 struct vhost_umem *umem; 140 struct vhost_umem *iotlb; 141 void *private_data; 142 u64 acked_features; 143 /* Log write descriptors */ 144 void __user *log_base; 145 struct vhost_log *log; 146 147 /* Ring endianness. Defaults to legacy native endianness. 148 * Set to true when starting a modern virtio device. */ 149 bool is_le; 150 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 151 /* Ring endianness requested by userspace for cross-endian support. */ 152 bool user_be; 153 #endif 154 u32 busyloop_timeout; 155 }; 156 157 struct vhost_msg_node { 158 struct vhost_msg msg; 159 struct vhost_virtqueue *vq; 160 struct list_head node; 161 }; 162 163 struct vhost_dev { 164 struct mm_struct *mm; 165 struct mutex mutex; 166 struct vhost_virtqueue **vqs; 167 int nvqs; 168 struct file *log_file; 169 struct eventfd_ctx *log_ctx; 170 struct llist_head work_list; 171 struct task_struct *worker; 172 struct vhost_umem *umem; 173 struct vhost_umem *iotlb; 174 spinlock_t iotlb_lock; 175 struct list_head read_list; 176 struct list_head pending_list; 177 wait_queue_head_t wait; 178 }; 179 180 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs); 181 long vhost_dev_set_owner(struct vhost_dev *dev); 182 bool vhost_dev_has_owner(struct vhost_dev *dev); 183 long vhost_dev_check_owner(struct vhost_dev *); 184 struct vhost_umem *vhost_dev_reset_owner_prepare(void); 185 void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *); 186 void vhost_dev_cleanup(struct vhost_dev *, bool locked); 187 void vhost_dev_stop(struct vhost_dev *); 188 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 189 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp); 190 int vhost_vq_access_ok(struct vhost_virtqueue *vq); 191 int vhost_log_access_ok(struct vhost_dev *); 192 193 int vhost_get_vq_desc(struct vhost_virtqueue *, 194 struct iovec iov[], unsigned int iov_count, 195 unsigned int *out_num, unsigned int *in_num, 196 struct vhost_log *log, unsigned int *log_num); 197 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); 198 199 int vhost_vq_init_access(struct vhost_virtqueue *); 200 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 201 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 202 unsigned count); 203 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 204 unsigned int id, int len); 205 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 206 struct vring_used_elem *heads, unsigned count); 207 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 208 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 209 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); 210 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 211 212 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 213 unsigned int log_num, u64 len); 214 int vq_iotlb_prefetch(struct vhost_virtqueue *vq); 215 216 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); 217 void vhost_enqueue_msg(struct vhost_dev *dev, 218 struct list_head *head, 219 struct vhost_msg_node *node); 220 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, 221 struct list_head *head); 222 unsigned int vhost_chr_poll(struct file *file, struct vhost_dev *dev, 223 poll_table *wait); 224 ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, 225 int noblock); 226 ssize_t vhost_chr_write_iter(struct vhost_dev *dev, 227 struct iov_iter *from); 228 int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled); 229 230 #define vq_err(vq, fmt, ...) do { \ 231 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 232 if ((vq)->error_ctx) \ 233 eventfd_signal((vq)->error_ctx, 1);\ 234 } while (0) 235 236 enum { 237 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 238 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | 239 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 240 (1ULL << VHOST_F_LOG_ALL) | 241 (1ULL << VIRTIO_F_ANY_LAYOUT) | 242 (1ULL << VIRTIO_F_VERSION_1) 243 }; 244 245 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 246 { 247 return vq->acked_features & (1ULL << bit); 248 } 249 250 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 251 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 252 { 253 return vq->is_le; 254 } 255 #else 256 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 257 { 258 return virtio_legacy_is_little_endian() || vq->is_le; 259 } 260 #endif 261 262 /* Memory accessors */ 263 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 264 { 265 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 266 } 267 268 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 269 { 270 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 271 } 272 273 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 274 { 275 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 276 } 277 278 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 279 { 280 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 281 } 282 283 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 284 { 285 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 286 } 287 288 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 289 { 290 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 291 } 292 #endif 293