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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef _VHOST_H3#define _VHOST_H4 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 18struct vhost_work;19struct vhost_task;20typedef void (*vhost_work_fn_t)(struct vhost_work *work);21 22#define VHOST_WORK_QUEUED 123struct vhost_work {24 struct llist_node node;25 vhost_work_fn_t fn;26 unsigned long flags;27};28 29struct vhost_worker {30 struct vhost_task *vtsk;31 struct vhost_dev *dev;32 /* Used to serialize device wide flushing with worker swapping. */33 struct mutex mutex;34 struct llist_head work_list;35 u64 kcov_handle;36 u32 id;37 int attachment_cnt;38 bool killed;39};40 41/* Poll a file (eventfd or socket) */42/* Note: there's nothing vhost specific about this structure. */43struct vhost_poll {44 poll_table table;45 wait_queue_head_t *wqh;46 wait_queue_entry_t wait;47 struct vhost_work work;48 __poll_t mask;49 struct vhost_dev *dev;50 struct vhost_virtqueue *vq;51};52 53void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,54 __poll_t mask, struct vhost_dev *dev,55 struct vhost_virtqueue *vq);56int vhost_poll_start(struct vhost_poll *poll, struct file *file);57void vhost_poll_stop(struct vhost_poll *poll);58void vhost_poll_queue(struct vhost_poll *poll);59 60void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);61void vhost_dev_flush(struct vhost_dev *dev);62 63struct vhost_log {64 u64 addr;65 u64 len;66};67 68enum vhost_uaddr_type {69 VHOST_ADDR_DESC = 0,70 VHOST_ADDR_AVAIL = 1,71 VHOST_ADDR_USED = 2,72 VHOST_NUM_ADDRS = 3,73};74 75struct vhost_vring_call {76 struct eventfd_ctx *ctx;77 struct irq_bypass_producer producer;78};79 80/* The virtqueue structure describes a queue attached to a device. */81struct vhost_virtqueue {82 struct vhost_dev *dev;83 struct vhost_worker __rcu *worker;84 85 /* The actual ring of buffers. */86 struct mutex mutex;87 unsigned int num;88 vring_desc_t __user *desc;89 vring_avail_t __user *avail;90 vring_used_t __user *used;91 const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];92 struct file *kick;93 struct vhost_vring_call call_ctx;94 struct eventfd_ctx *error_ctx;95 struct eventfd_ctx *log_ctx;96 97 struct vhost_poll poll;98 99 /* The routine to call when the Guest pings us, or timeout. */100 vhost_work_fn_t handle_kick;101 102 /* Last available index we saw.103 * Values are limited to 0x7fff, and the high bit is used as104 * a wrap counter when using VIRTIO_F_RING_PACKED. */105 u16 last_avail_idx;106 107 /* Caches available index value from user. */108 u16 avail_idx;109 110 /* Last index we used.111 * Values are limited to 0x7fff, and the high bit is used as112 * a wrap counter when using VIRTIO_F_RING_PACKED. */113 u16 last_used_idx;114 115 /* Used flags */116 u16 used_flags;117 118 /* Last used index value we have signalled on */119 u16 signalled_used;120 121 /* Last used index value we have signalled on */122 bool signalled_used_valid;123 124 /* Log writes to used structure. */125 bool log_used;126 u64 log_addr;127 128 struct iovec iov[UIO_MAXIOV];129 struct iovec iotlb_iov[64];130 struct iovec *indirect;131 struct vring_used_elem *heads;132 /* Protected by virtqueue mutex. */133 struct vhost_iotlb *umem;134 struct vhost_iotlb *iotlb;135 void *private_data;136 u64 acked_features;137 u64 acked_backend_features;138 /* Log write descriptors */139 void __user *log_base;140 struct vhost_log *log;141 struct iovec log_iov[64];142 143 /* Ring endianness. Defaults to legacy native endianness.144 * Set to true when starting a modern virtio device. */145 bool is_le;146#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY147 /* Ring endianness requested by userspace for cross-endian support. */148 bool user_be;149#endif150 u32 busyloop_timeout;151};152 153struct vhost_msg_node {154 union {155 struct vhost_msg msg;156 struct vhost_msg_v2 msg_v2;157 };158 struct vhost_virtqueue *vq;159 struct list_head node;160};161 162struct vhost_dev {163 struct mm_struct *mm;164 struct mutex mutex;165 struct vhost_virtqueue **vqs;166 int nvqs;167 struct eventfd_ctx *log_ctx;168 struct vhost_iotlb *umem;169 struct vhost_iotlb *iotlb;170 spinlock_t iotlb_lock;171 struct list_head read_list;172 struct list_head pending_list;173 wait_queue_head_t wait;174 int iov_limit;175 int weight;176 int byte_weight;177 struct xarray worker_xa;178 bool use_worker;179 int (*msg_handler)(struct vhost_dev *dev, u32 asid,180 struct vhost_iotlb_msg *msg);181};182 183bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);184void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,185 int nvqs, int iov_limit, int weight, int byte_weight,186 bool use_worker,187 int (*msg_handler)(struct vhost_dev *dev, u32 asid,188 struct vhost_iotlb_msg *msg));189long vhost_dev_set_owner(struct vhost_dev *dev);190bool vhost_dev_has_owner(struct vhost_dev *dev);191long vhost_dev_check_owner(struct vhost_dev *);192struct vhost_iotlb *vhost_dev_reset_owner_prepare(void);193void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb);194void vhost_dev_cleanup(struct vhost_dev *);195void vhost_dev_stop(struct vhost_dev *);196long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);197long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);198long vhost_worker_ioctl(struct vhost_dev *dev, unsigned int ioctl,199 void __user *argp);200bool vhost_vq_access_ok(struct vhost_virtqueue *vq);201bool vhost_log_access_ok(struct vhost_dev *);202void vhost_clear_msg(struct vhost_dev *dev);203 204int vhost_get_vq_desc(struct vhost_virtqueue *,205 struct iovec iov[], unsigned int iov_size,206 unsigned int *out_num, unsigned int *in_num,207 struct vhost_log *log, unsigned int *log_num);208void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);209 210bool vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work);211bool vhost_vq_has_work(struct vhost_virtqueue *vq);212bool vhost_vq_is_setup(struct vhost_virtqueue *vq);213int vhost_vq_init_access(struct vhost_virtqueue *);214int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);215int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,216 unsigned count);217void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,218 unsigned int id, int len);219void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,220 struct vring_used_elem *heads, unsigned count);221void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);222void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);223bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);224bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);225 226int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,227 unsigned int log_num, u64 len,228 struct iovec *iov, int count);229int vq_meta_prefetch(struct vhost_virtqueue *vq);230 231struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);232void vhost_enqueue_msg(struct vhost_dev *dev,233 struct list_head *head,234 struct vhost_msg_node *node);235struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,236 struct list_head *head);237void vhost_set_backend_features(struct vhost_dev *dev, u64 features);238 239__poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev,240 poll_table *wait);241ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,242 int noblock);243ssize_t vhost_chr_write_iter(struct vhost_dev *dev,244 struct iov_iter *from);245int vhost_init_device_iotlb(struct vhost_dev *d);246 247void vhost_iotlb_map_free(struct vhost_iotlb *iotlb,248 struct vhost_iotlb_map *map);249 250#define vq_err(vq, fmt, ...) do { \251 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \252 if ((vq)->error_ctx) \253 eventfd_signal((vq)->error_ctx);\254 } while (0)255 256enum {257 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |258 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |259 (1ULL << VIRTIO_RING_F_EVENT_IDX) |260 (1ULL << VHOST_F_LOG_ALL) |261 (1ULL << VIRTIO_F_ANY_LAYOUT) |262 (1ULL << VIRTIO_F_VERSION_1)263};264 265/**266 * vhost_vq_set_backend - Set backend.267 *268 * @vq Virtqueue.269 * @private_data The private data.270 *271 * Context: Need to call with vq->mutex acquired.272 */273static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq,274 void *private_data)275{276 vq->private_data = private_data;277}278 279/**280 * vhost_vq_get_backend - Get backend.281 *282 * @vq Virtqueue.283 *284 * Context: Need to call with vq->mutex acquired.285 * Return: Private data previously set with vhost_vq_set_backend.286 */287static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq)288{289 return vq->private_data;290}291 292static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)293{294 return vq->acked_features & (1ULL << bit);295}296 297static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit)298{299 return vq->acked_backend_features & (1ULL << bit);300}301 302#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY303static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)304{305 return vq->is_le;306}307#else308static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)309{310 return virtio_legacy_is_little_endian() || vq->is_le;311}312#endif313 314/* Memory accessors */315static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)316{317 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);318}319 320static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)321{322 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);323}324 325static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)326{327 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);328}329 330static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)331{332 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);333}334 335static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)336{337 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);338}339 340static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)341{342 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);343}344#endif345