1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <linux/eventfd.h>
6 #include <linux/vhost.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>
17 typedef void (*vhost_work_fn_t)(struct vhost_work *work);
19 #define VHOST_WORK_QUEUED 1
21 struct llist_node node;
23 wait_queue_head_t done;
30 /* Poll a file (eventfd or socket) */
31 /* Note: there's nothing vhost specific about this structure. */
34 wait_queue_head_t *wqh;
35 wait_queue_entry_t wait;
36 struct vhost_work work;
38 struct vhost_dev *dev;
41 void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
42 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
43 bool vhost_has_work(struct vhost_dev *dev);
45 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
46 unsigned long mask, struct vhost_dev *dev);
47 int vhost_poll_start(struct vhost_poll *poll, struct file *file);
48 void vhost_poll_stop(struct vhost_poll *poll);
49 void vhost_poll_flush(struct vhost_poll *poll);
50 void vhost_poll_queue(struct vhost_poll *poll);
51 void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
52 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
59 #define START(node) ((node)->start)
60 #define LAST(node) ((node)->last)
62 struct vhost_umem_node {
64 struct list_head link;
75 struct rb_root_cached umem_tree;
76 struct list_head umem_list;
80 enum vhost_uaddr_type {
87 /* The virtqueue structure describes a queue attached to a device. */
88 struct vhost_virtqueue {
89 struct vhost_dev *dev;
91 /* The actual ring of buffers. */
94 struct vring_desc __user *desc;
95 struct vring_avail __user *avail;
96 struct vring_used __user *used;
97 const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
101 struct eventfd_ctx *call_ctx;
102 struct eventfd_ctx *error_ctx;
103 struct eventfd_ctx *log_ctx;
105 struct vhost_poll poll;
107 /* The routine to call when the Guest pings us, or timeout. */
108 vhost_work_fn_t handle_kick;
110 /* Last available index we saw. */
113 /* Caches available index value from user. */
116 /* Last index we used. */
122 /* Last used index value we have signalled on */
125 /* Last used index value we have signalled on */
126 bool signalled_used_valid;
128 /* Log writes to used structure. */
132 struct iovec iov[UIO_MAXIOV];
133 struct iovec iotlb_iov[64];
134 struct iovec *indirect;
135 struct vring_used_elem *heads;
136 /* Protected by virtqueue mutex. */
137 struct vhost_umem *umem;
138 struct vhost_umem *iotlb;
141 /* Log write descriptors */
142 void __user *log_base;
143 struct vhost_log *log;
145 /* Ring endianness. Defaults to legacy native endianness.
146 * Set to true when starting a modern virtio device. */
148 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
149 /* Ring endianness requested by userspace for cross-endian support. */
152 u32 busyloop_timeout;
155 struct vhost_msg_node {
156 struct vhost_msg msg;
157 struct vhost_virtqueue *vq;
158 struct list_head node;
162 struct mm_struct *mm;
164 struct vhost_virtqueue **vqs;
166 struct file *log_file;
167 struct eventfd_ctx *log_ctx;
168 struct llist_head work_list;
169 struct task_struct *worker;
170 struct vhost_umem *umem;
171 struct vhost_umem *iotlb;
172 spinlock_t iotlb_lock;
173 struct list_head read_list;
174 struct list_head pending_list;
175 wait_queue_head_t wait;
180 bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
181 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
182 int nvqs, int weight, int byte_weight);
183 long vhost_dev_set_owner(struct vhost_dev *dev);
184 bool vhost_dev_has_owner(struct vhost_dev *dev);
185 long vhost_dev_check_owner(struct vhost_dev *);
186 struct vhost_umem *vhost_dev_reset_owner_prepare(void);
187 void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
188 void vhost_dev_cleanup(struct vhost_dev *, bool locked);
189 void vhost_dev_stop(struct vhost_dev *);
190 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
191 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
192 int vhost_vq_access_ok(struct vhost_virtqueue *vq);
193 int vhost_log_access_ok(struct vhost_dev *);
195 int vhost_get_vq_desc(struct vhost_virtqueue *,
196 struct iovec iov[], unsigned int iov_count,
197 unsigned int *out_num, unsigned int *in_num,
198 struct vhost_log *log, unsigned int *log_num);
199 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
201 int vhost_vq_init_access(struct vhost_virtqueue *);
202 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
203 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
205 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
206 unsigned int id, int len);
207 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
208 struct vring_used_elem *heads, unsigned count);
209 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
210 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
211 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
212 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
214 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
215 unsigned int log_num, u64 len,
216 struct iovec *iov, int count);
217 int vq_iotlb_prefetch(struct vhost_virtqueue *vq);
219 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
220 void vhost_enqueue_msg(struct vhost_dev *dev,
221 struct list_head *head,
222 struct vhost_msg_node *node);
223 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
224 struct list_head *head);
225 unsigned int vhost_chr_poll(struct file *file, struct vhost_dev *dev,
227 ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
229 ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
230 struct iov_iter *from);
231 int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);
233 #define vq_err(vq, fmt, ...) do { \
234 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
235 if ((vq)->error_ctx) \
236 eventfd_signal((vq)->error_ctx, 1);\
240 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
241 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
242 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
243 (1ULL << VHOST_F_LOG_ALL) |
244 (1ULL << VIRTIO_F_ANY_LAYOUT) |
245 (1ULL << VIRTIO_F_VERSION_1)
248 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
250 return vq->acked_features & (1ULL << bit);
253 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
254 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
259 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
261 return virtio_legacy_is_little_endian() || vq->is_le;
265 /* Memory accessors */
266 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
268 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
271 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
273 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
276 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
278 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
281 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
283 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
286 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
288 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
291 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
293 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);