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 #include <linux/irqbypass.h> 17 18 struct vhost_work; 19 typedef void (*vhost_work_fn_t)(struct vhost_work *work); 20 21 #define VHOST_WORK_QUEUED 1 22 struct vhost_work { 23 struct llist_node node; 24 vhost_work_fn_t fn; 25 unsigned long flags; 26 }; 27 28 /* Poll a file (eventfd or socket) */ 29 /* Note: there's nothing vhost specific about this structure. */ 30 struct vhost_poll { 31 poll_table table; 32 wait_queue_head_t *wqh; 33 wait_queue_entry_t wait; 34 struct vhost_work work; 35 __poll_t mask; 36 struct vhost_dev *dev; 37 }; 38 39 void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn); 40 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work); 41 bool vhost_has_work(struct vhost_dev *dev); 42 43 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, 44 __poll_t mask, struct vhost_dev *dev); 45 int vhost_poll_start(struct vhost_poll *poll, struct file *file); 46 void vhost_poll_stop(struct vhost_poll *poll); 47 void vhost_poll_flush(struct vhost_poll *poll); 48 void vhost_poll_queue(struct vhost_poll *poll); 49 void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work); 50 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); 51 52 struct vhost_log { 53 u64 addr; 54 u64 len; 55 }; 56 57 enum vhost_uaddr_type { 58 VHOST_ADDR_DESC = 0, 59 VHOST_ADDR_AVAIL = 1, 60 VHOST_ADDR_USED = 2, 61 VHOST_NUM_ADDRS = 3, 62 }; 63 64 struct vhost_vring_call { 65 struct eventfd_ctx *ctx; 66 struct irq_bypass_producer producer; 67 spinlock_t ctx_lock; 68 }; 69 70 /* The virtqueue structure describes a queue attached to a device. */ 71 struct vhost_virtqueue { 72 struct vhost_dev *dev; 73 74 /* The actual ring of buffers. */ 75 struct mutex mutex; 76 unsigned int num; 77 vring_desc_t __user *desc; 78 vring_avail_t __user *avail; 79 vring_used_t __user *used; 80 const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS]; 81 struct file *kick; 82 struct vhost_vring_call call_ctx; 83 struct eventfd_ctx *error_ctx; 84 struct eventfd_ctx *log_ctx; 85 86 struct vhost_poll poll; 87 88 /* The routine to call when the Guest pings us, or timeout. */ 89 vhost_work_fn_t handle_kick; 90 91 /* Last available index we saw. */ 92 u16 last_avail_idx; 93 94 /* Caches available index value from user. */ 95 u16 avail_idx; 96 97 /* Last index we used. */ 98 u16 last_used_idx; 99 100 /* Used flags */ 101 u16 used_flags; 102 103 /* Last used index value we have signalled on */ 104 u16 signalled_used; 105 106 /* Last used index value we have signalled on */ 107 bool signalled_used_valid; 108 109 /* Log writes to used structure. */ 110 bool log_used; 111 u64 log_addr; 112 113 struct iovec iov[UIO_MAXIOV]; 114 struct iovec iotlb_iov[64]; 115 struct iovec *indirect; 116 struct vring_used_elem *heads; 117 /* Protected by virtqueue mutex. */ 118 struct vhost_iotlb *umem; 119 struct vhost_iotlb *iotlb; 120 void *private_data; 121 u64 acked_features; 122 u64 acked_backend_features; 123 /* Log write descriptors */ 124 void __user *log_base; 125 struct vhost_log *log; 126 127 /* Ring endianness. Defaults to legacy native endianness. 128 * Set to true when starting a modern virtio device. */ 129 bool is_le; 130 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 131 /* Ring endianness requested by userspace for cross-endian support. */ 132 bool user_be; 133 #endif 134 u32 busyloop_timeout; 135 }; 136 137 struct vhost_msg_node { 138 union { 139 struct vhost_msg msg; 140 struct vhost_msg_v2 msg_v2; 141 }; 142 struct vhost_virtqueue *vq; 143 struct list_head node; 144 }; 145 146 struct vhost_dev { 147 struct mm_struct *mm; 148 struct mutex mutex; 149 struct vhost_virtqueue **vqs; 150 int nvqs; 151 struct eventfd_ctx *log_ctx; 152 struct llist_head work_list; 153 struct task_struct *worker; 154 struct vhost_iotlb *umem; 155 struct vhost_iotlb *iotlb; 156 spinlock_t iotlb_lock; 157 struct list_head read_list; 158 struct list_head pending_list; 159 wait_queue_head_t wait; 160 int iov_limit; 161 int weight; 162 int byte_weight; 163 u64 kcov_handle; 164 bool use_worker; 165 int (*msg_handler)(struct vhost_dev *dev, 166 struct vhost_iotlb_msg *msg); 167 }; 168 169 bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); 170 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, 171 int nvqs, int iov_limit, int weight, int byte_weight, 172 bool use_worker, 173 int (*msg_handler)(struct vhost_dev *dev, 174 struct vhost_iotlb_msg *msg)); 175 long vhost_dev_set_owner(struct vhost_dev *dev); 176 bool vhost_dev_has_owner(struct vhost_dev *dev); 177 long vhost_dev_check_owner(struct vhost_dev *); 178 struct vhost_iotlb *vhost_dev_reset_owner_prepare(void); 179 void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb); 180 void vhost_dev_cleanup(struct vhost_dev *); 181 void vhost_dev_stop(struct vhost_dev *); 182 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 183 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); 184 bool vhost_vq_access_ok(struct vhost_virtqueue *vq); 185 bool vhost_log_access_ok(struct vhost_dev *); 186 187 int vhost_get_vq_desc(struct vhost_virtqueue *, 188 struct iovec iov[], unsigned int iov_count, 189 unsigned int *out_num, unsigned int *in_num, 190 struct vhost_log *log, unsigned int *log_num); 191 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); 192 193 int vhost_vq_init_access(struct vhost_virtqueue *); 194 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 195 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 196 unsigned count); 197 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 198 unsigned int id, int len); 199 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 200 struct vring_used_elem *heads, unsigned count); 201 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 202 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 203 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); 204 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 205 206 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 207 unsigned int log_num, u64 len, 208 struct iovec *iov, int count); 209 int vq_meta_prefetch(struct vhost_virtqueue *vq); 210 211 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); 212 void vhost_enqueue_msg(struct vhost_dev *dev, 213 struct list_head *head, 214 struct vhost_msg_node *node); 215 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, 216 struct list_head *head); 217 void vhost_set_backend_features(struct vhost_dev *dev, u64 features); 218 219 __poll_t 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 void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, 228 struct vhost_iotlb_map *map); 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 /** 246 * vhost_vq_set_backend - Set backend. 247 * 248 * @vq Virtqueue. 249 * @private_data The private data. 250 * 251 * Context: Need to call with vq->mutex acquired. 252 */ 253 static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq, 254 void *private_data) 255 { 256 vq->private_data = private_data; 257 } 258 259 /** 260 * vhost_vq_get_backend - Get backend. 261 * 262 * @vq Virtqueue. 263 * 264 * Context: Need to call with vq->mutex acquired. 265 * Return: Private data previously set with vhost_vq_set_backend. 266 */ 267 static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq) 268 { 269 return vq->private_data; 270 } 271 272 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 273 { 274 return vq->acked_features & (1ULL << bit); 275 } 276 277 static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit) 278 { 279 return vq->acked_backend_features & (1ULL << bit); 280 } 281 282 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 283 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 284 { 285 return vq->is_le; 286 } 287 #else 288 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 289 { 290 return virtio_legacy_is_little_endian() || vq->is_le; 291 } 292 #endif 293 294 /* Memory accessors */ 295 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 296 { 297 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 298 } 299 300 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 301 { 302 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 303 } 304 305 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 306 { 307 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 308 } 309 310 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 311 { 312 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 313 } 314 315 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 316 { 317 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 318 } 319 320 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 321 { 322 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 323 } 324 #endif 325