1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _VHOST_H 3 #define _VHOST_H 4 5 #include <linux/eventfd.h> 6 #include <linux/vhost.h> 7 #include <linux/mm.h> 8 #include <linux/mutex.h> 9 #include <linux/poll.h> 10 #include <linux/file.h> 11 #include <linux/uio.h> 12 #include <linux/virtio_config.h> 13 #include <linux/virtio_ring.h> 14 #include <linux/atomic.h> 15 #include <linux/vhost_iotlb.h> 16 17 struct vhost_work; 18 typedef void (*vhost_work_fn_t)(struct vhost_work *work); 19 20 #define VHOST_WORK_QUEUED 1 21 struct vhost_work { 22 struct llist_node node; 23 vhost_work_fn_t fn; 24 unsigned long flags; 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_entry_t wait; 33 struct vhost_work work; 34 __poll_t 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 bool vhost_has_work(struct vhost_dev *dev); 41 42 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, 43 __poll_t mask, struct vhost_dev *dev); 44 int vhost_poll_start(struct vhost_poll *poll, struct file *file); 45 void vhost_poll_stop(struct vhost_poll *poll); 46 void vhost_poll_flush(struct vhost_poll *poll); 47 void vhost_poll_queue(struct vhost_poll *poll); 48 void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work); 49 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); 50 51 struct vhost_log { 52 u64 addr; 53 u64 len; 54 }; 55 56 enum vhost_uaddr_type { 57 VHOST_ADDR_DESC = 0, 58 VHOST_ADDR_AVAIL = 1, 59 VHOST_ADDR_USED = 2, 60 VHOST_NUM_ADDRS = 3, 61 }; 62 63 /* The virtqueue structure describes a queue attached to a device. */ 64 struct vhost_virtqueue { 65 struct vhost_dev *dev; 66 67 /* The actual ring of buffers. */ 68 struct mutex mutex; 69 unsigned int num; 70 struct vring_desc __user *desc; 71 struct vring_avail __user *avail; 72 struct vring_used __user *used; 73 const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS]; 74 struct file *kick; 75 struct eventfd_ctx *call_ctx; 76 struct eventfd_ctx *error_ctx; 77 struct eventfd_ctx *log_ctx; 78 79 struct vhost_poll poll; 80 81 /* The routine to call when the Guest pings us, or timeout. */ 82 vhost_work_fn_t handle_kick; 83 84 /* Last available index we saw. */ 85 u16 last_avail_idx; 86 87 /* Caches available index value from user. */ 88 u16 avail_idx; 89 90 /* Last index we used. */ 91 u16 last_used_idx; 92 93 /* Used flags */ 94 u16 used_flags; 95 96 /* Last used index value we have signalled on */ 97 u16 signalled_used; 98 99 /* Last used index value we have signalled on */ 100 bool signalled_used_valid; 101 102 /* Log writes to used structure. */ 103 bool log_used; 104 u64 log_addr; 105 106 struct iovec iov[UIO_MAXIOV]; 107 struct iovec iotlb_iov[64]; 108 struct iovec *indirect; 109 struct vring_used_elem *heads; 110 /* Protected by virtqueue mutex. */ 111 struct vhost_iotlb *umem; 112 struct vhost_iotlb *iotlb; 113 void *private_data; 114 u64 acked_features; 115 u64 acked_backend_features; 116 /* Log write descriptors */ 117 void __user *log_base; 118 struct vhost_log *log; 119 120 /* Ring endianness. Defaults to legacy native endianness. 121 * Set to true when starting a modern virtio device. */ 122 bool is_le; 123 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 124 /* Ring endianness requested by userspace for cross-endian support. */ 125 bool user_be; 126 #endif 127 u32 busyloop_timeout; 128 }; 129 130 struct vhost_msg_node { 131 union { 132 struct vhost_msg msg; 133 struct vhost_msg_v2 msg_v2; 134 }; 135 struct vhost_virtqueue *vq; 136 struct list_head node; 137 }; 138 139 struct vhost_dev { 140 struct mm_struct *mm; 141 struct mutex mutex; 142 struct vhost_virtqueue **vqs; 143 int nvqs; 144 struct eventfd_ctx *log_ctx; 145 struct llist_head work_list; 146 struct task_struct *worker; 147 struct vhost_iotlb *umem; 148 struct vhost_iotlb *iotlb; 149 spinlock_t iotlb_lock; 150 struct list_head read_list; 151 struct list_head pending_list; 152 wait_queue_head_t wait; 153 int iov_limit; 154 int weight; 155 int byte_weight; 156 u64 kcov_handle; 157 int (*msg_handler)(struct vhost_dev *dev, 158 struct vhost_iotlb_msg *msg); 159 }; 160 161 bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); 162 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, 163 int nvqs, int iov_limit, int weight, int byte_weight, 164 int (*msg_handler)(struct vhost_dev *dev, 165 struct vhost_iotlb_msg *msg)); 166 long vhost_dev_set_owner(struct vhost_dev *dev); 167 bool vhost_dev_has_owner(struct vhost_dev *dev); 168 long vhost_dev_check_owner(struct vhost_dev *); 169 struct vhost_iotlb *vhost_dev_reset_owner_prepare(void); 170 void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb); 171 void vhost_dev_cleanup(struct vhost_dev *); 172 void vhost_dev_stop(struct vhost_dev *); 173 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 174 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); 175 bool vhost_vq_access_ok(struct vhost_virtqueue *vq); 176 bool vhost_log_access_ok(struct vhost_dev *); 177 178 int vhost_get_vq_desc(struct vhost_virtqueue *, 179 struct iovec iov[], unsigned int iov_count, 180 unsigned int *out_num, unsigned int *in_num, 181 struct vhost_log *log, unsigned int *log_num); 182 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); 183 184 int vhost_vq_init_access(struct vhost_virtqueue *); 185 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 186 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 187 unsigned count); 188 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 189 unsigned int id, int len); 190 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 191 struct vring_used_elem *heads, unsigned count); 192 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 193 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 194 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); 195 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 196 197 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 198 unsigned int log_num, u64 len, 199 struct iovec *iov, int count); 200 int vq_meta_prefetch(struct vhost_virtqueue *vq); 201 202 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); 203 void vhost_enqueue_msg(struct vhost_dev *dev, 204 struct list_head *head, 205 struct vhost_msg_node *node); 206 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, 207 struct list_head *head); 208 __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, 209 poll_table *wait); 210 ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, 211 int noblock); 212 ssize_t vhost_chr_write_iter(struct vhost_dev *dev, 213 struct iov_iter *from); 214 int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled); 215 216 void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, 217 struct vhost_iotlb_map *map); 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 /** 235 * vhost_vq_set_backend - Set backend. 236 * 237 * @vq Virtqueue. 238 * @private_data The private data. 239 * 240 * Context: Need to call with vq->mutex acquired. 241 */ 242 static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq, 243 void *private_data) 244 { 245 vq->private_data = private_data; 246 } 247 248 /** 249 * vhost_vq_get_backend - Get backend. 250 * 251 * @vq Virtqueue. 252 * 253 * Context: Need to call with vq->mutex acquired. 254 * Return: Private data previously set with vhost_vq_set_backend. 255 */ 256 static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq) 257 { 258 return vq->private_data; 259 } 260 261 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 262 { 263 return vq->acked_features & (1ULL << bit); 264 } 265 266 static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit) 267 { 268 return vq->acked_backend_features & (1ULL << bit); 269 } 270 271 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 272 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 273 { 274 return vq->is_le; 275 } 276 #else 277 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 278 { 279 return virtio_legacy_is_little_endian() || vq->is_le; 280 } 281 #endif 282 283 /* Memory accessors */ 284 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 285 { 286 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 287 } 288 289 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 290 { 291 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 292 } 293 294 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 295 { 296 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 297 } 298 299 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 300 { 301 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 302 } 303 304 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 305 { 306 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 307 } 308 309 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 310 { 311 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 312 } 313 #endif 314