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 vring_desc_t __user *desc; 71 vring_avail_t __user *avail; 72 vring_used_t __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 bool use_worker; 158 int (*msg_handler)(struct vhost_dev *dev, 159 struct vhost_iotlb_msg *msg); 160 }; 161 162 bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); 163 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, 164 int nvqs, int iov_limit, int weight, int byte_weight, 165 bool use_worker, 166 int (*msg_handler)(struct vhost_dev *dev, 167 struct vhost_iotlb_msg *msg)); 168 long vhost_dev_set_owner(struct vhost_dev *dev); 169 bool vhost_dev_has_owner(struct vhost_dev *dev); 170 long vhost_dev_check_owner(struct vhost_dev *); 171 struct vhost_iotlb *vhost_dev_reset_owner_prepare(void); 172 void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb); 173 void vhost_dev_cleanup(struct vhost_dev *); 174 void vhost_dev_stop(struct vhost_dev *); 175 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 176 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); 177 bool vhost_vq_access_ok(struct vhost_virtqueue *vq); 178 bool vhost_log_access_ok(struct vhost_dev *); 179 180 int vhost_get_vq_desc(struct vhost_virtqueue *, 181 struct iovec iov[], unsigned int iov_count, 182 unsigned int *out_num, unsigned int *in_num, 183 struct vhost_log *log, unsigned int *log_num); 184 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); 185 186 int vhost_vq_init_access(struct vhost_virtqueue *); 187 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 188 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 189 unsigned count); 190 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 191 unsigned int id, int len); 192 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 193 struct vring_used_elem *heads, unsigned count); 194 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 195 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 196 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); 197 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 198 199 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 200 unsigned int log_num, u64 len, 201 struct iovec *iov, int count); 202 int vq_meta_prefetch(struct vhost_virtqueue *vq); 203 204 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); 205 void vhost_enqueue_msg(struct vhost_dev *dev, 206 struct list_head *head, 207 struct vhost_msg_node *node); 208 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, 209 struct list_head *head); 210 __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, 211 poll_table *wait); 212 ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, 213 int noblock); 214 ssize_t vhost_chr_write_iter(struct vhost_dev *dev, 215 struct iov_iter *from); 216 int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled); 217 218 void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, 219 struct vhost_iotlb_map *map); 220 221 #define vq_err(vq, fmt, ...) do { \ 222 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 223 if ((vq)->error_ctx) \ 224 eventfd_signal((vq)->error_ctx, 1);\ 225 } while (0) 226 227 enum { 228 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 229 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | 230 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 231 (1ULL << VHOST_F_LOG_ALL) | 232 (1ULL << VIRTIO_F_ANY_LAYOUT) | 233 (1ULL << VIRTIO_F_VERSION_1) 234 }; 235 236 /** 237 * vhost_vq_set_backend - Set backend. 238 * 239 * @vq Virtqueue. 240 * @private_data The private data. 241 * 242 * Context: Need to call with vq->mutex acquired. 243 */ 244 static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq, 245 void *private_data) 246 { 247 vq->private_data = private_data; 248 } 249 250 /** 251 * vhost_vq_get_backend - Get backend. 252 * 253 * @vq Virtqueue. 254 * 255 * Context: Need to call with vq->mutex acquired. 256 * Return: Private data previously set with vhost_vq_set_backend. 257 */ 258 static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq) 259 { 260 return vq->private_data; 261 } 262 263 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 264 { 265 return vq->acked_features & (1ULL << bit); 266 } 267 268 static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit) 269 { 270 return vq->acked_backend_features & (1ULL << bit); 271 } 272 273 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 274 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 275 { 276 return vq->is_le; 277 } 278 #else 279 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 280 { 281 return virtio_legacy_is_little_endian() || vq->is_le; 282 } 283 #endif 284 285 /* Memory accessors */ 286 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 287 { 288 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 289 } 290 291 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 292 { 293 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 294 } 295 296 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 297 { 298 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 299 } 300 301 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 302 { 303 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 304 } 305 306 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 307 { 308 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 309 } 310 311 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 312 { 313 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 314 } 315 #endif 316