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