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_entry_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 /* Used flags */ 119 u16 used_flags; 120 121 /* Last used index value we have signalled on */ 122 u16 signalled_used; 123 124 /* Last used index value we have signalled on */ 125 bool signalled_used_valid; 126 127 /* Log writes to used structure. */ 128 bool log_used; 129 u64 log_addr; 130 131 struct iovec iov[UIO_MAXIOV]; 132 struct iovec iotlb_iov[64]; 133 struct iovec *indirect; 134 struct vring_used_elem *heads; 135 /* Protected by virtqueue mutex. */ 136 struct vhost_umem *umem; 137 struct vhost_umem *iotlb; 138 void *private_data; 139 u64 acked_features; 140 /* Log write descriptors */ 141 void __user *log_base; 142 struct vhost_log *log; 143 144 /* Ring endianness. Defaults to legacy native endianness. 145 * Set to true when starting a modern virtio device. */ 146 bool is_le; 147 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 148 /* Ring endianness requested by userspace for cross-endian support. */ 149 bool user_be; 150 #endif 151 u32 busyloop_timeout; 152 }; 153 154 struct vhost_msg_node { 155 struct vhost_msg msg; 156 struct vhost_virtqueue *vq; 157 struct list_head node; 158 }; 159 160 struct vhost_dev { 161 struct mm_struct *mm; 162 struct mutex mutex; 163 struct vhost_virtqueue **vqs; 164 int nvqs; 165 struct file *log_file; 166 struct eventfd_ctx *log_ctx; 167 struct llist_head work_list; 168 struct task_struct *worker; 169 struct vhost_umem *umem; 170 struct vhost_umem *iotlb; 171 spinlock_t iotlb_lock; 172 struct list_head read_list; 173 struct list_head pending_list; 174 wait_queue_head_t wait; 175 }; 176 177 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs); 178 long vhost_dev_set_owner(struct vhost_dev *dev); 179 bool vhost_dev_has_owner(struct vhost_dev *dev); 180 long vhost_dev_check_owner(struct vhost_dev *); 181 struct vhost_umem *vhost_dev_reset_owner_prepare(void); 182 void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *); 183 void vhost_dev_cleanup(struct vhost_dev *, bool locked); 184 void vhost_dev_stop(struct vhost_dev *); 185 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 186 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp); 187 int vhost_vq_access_ok(struct vhost_virtqueue *vq); 188 int vhost_log_access_ok(struct vhost_dev *); 189 190 int vhost_get_vq_desc(struct vhost_virtqueue *, 191 struct iovec iov[], unsigned int iov_count, 192 unsigned int *out_num, unsigned int *in_num, 193 struct vhost_log *log, unsigned int *log_num); 194 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); 195 196 int vhost_vq_init_access(struct vhost_virtqueue *); 197 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 198 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 199 unsigned count); 200 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 201 unsigned int id, int len); 202 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 203 struct vring_used_elem *heads, unsigned count); 204 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 205 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 206 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); 207 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 208 209 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 210 unsigned int log_num, u64 len); 211 int vq_iotlb_prefetch(struct vhost_virtqueue *vq); 212 213 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); 214 void vhost_enqueue_msg(struct vhost_dev *dev, 215 struct list_head *head, 216 struct vhost_msg_node *node); 217 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, 218 struct list_head *head); 219 unsigned int vhost_chr_poll(struct file *file, struct vhost_dev *dev, 220 poll_table *wait); 221 ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, 222 int noblock); 223 ssize_t vhost_chr_write_iter(struct vhost_dev *dev, 224 struct iov_iter *from); 225 int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled); 226 227 #define vq_err(vq, fmt, ...) do { \ 228 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 229 if ((vq)->error_ctx) \ 230 eventfd_signal((vq)->error_ctx, 1);\ 231 } while (0) 232 233 enum { 234 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 235 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | 236 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 237 (1ULL << VHOST_F_LOG_ALL) | 238 (1ULL << VIRTIO_F_ANY_LAYOUT) | 239 (1ULL << VIRTIO_F_VERSION_1) 240 }; 241 242 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 243 { 244 return vq->acked_features & (1ULL << bit); 245 } 246 247 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 248 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 249 { 250 return vq->is_le; 251 } 252 #else 253 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 254 { 255 return virtio_legacy_is_little_endian() || vq->is_le; 256 } 257 #endif 258 259 /* Memory accessors */ 260 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 261 { 262 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 263 } 264 265 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 266 { 267 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 268 } 269 270 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 271 { 272 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 273 } 274 275 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 276 { 277 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 278 } 279 280 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 281 { 282 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 283 } 284 285 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 286 { 287 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 288 } 289 #endif 290