4 #include <linux/eventfd.h>
5 #include <linux/vhost.h>
7 #include <linux/mutex.h>
8 #include <linux/poll.h>
9 #include <linux/file.h>
10 #include <linux/uio.h>
11 #include <linux/virtio_config.h>
12 #include <linux/virtio_ring.h>
13 #include <linux/atomic.h>
16 typedef void (*vhost_work_fn_t)(struct vhost_work *work);
18 #define VHOST_WORK_QUEUED 1
20 struct llist_node node;
22 wait_queue_head_t done;
29 /* Poll a file (eventfd or socket) */
30 /* Note: there's nothing vhost specific about this structure. */
33 wait_queue_head_t *wqh;
35 struct vhost_work work;
37 struct vhost_dev *dev;
40 void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
41 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
42 bool vhost_has_work(struct vhost_dev *dev);
44 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
45 unsigned long mask, struct vhost_dev *dev);
46 int vhost_poll_start(struct vhost_poll *poll, struct file *file);
47 void vhost_poll_stop(struct vhost_poll *poll);
48 void vhost_poll_flush(struct vhost_poll *poll);
49 void vhost_poll_queue(struct vhost_poll *poll);
50 void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
51 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
58 #define START(node) ((node)->start)
59 #define LAST(node) ((node)->last)
61 struct vhost_umem_node {
63 struct list_head link;
73 struct rb_root umem_tree;
74 struct list_head umem_list;
77 /* The virtqueue structure describes a queue attached to a device. */
78 struct vhost_virtqueue {
79 struct vhost_dev *dev;
81 /* The actual ring of buffers. */
84 struct vring_desc __user *desc;
85 struct vring_avail __user *avail;
86 struct vring_used __user *used;
90 struct eventfd_ctx *call_ctx;
91 struct eventfd_ctx *error_ctx;
92 struct eventfd_ctx *log_ctx;
94 struct vhost_poll poll;
96 /* The routine to call when the Guest pings us, or timeout. */
97 vhost_work_fn_t handle_kick;
99 /* Last available index we saw. */
102 /* Caches available index value from user. */
105 /* Last index we used. */
111 /* Last used index value we have signalled on */
114 /* Last used index value we have signalled on */
115 bool signalled_used_valid;
117 /* Log writes to used structure. */
121 struct iovec iov[UIO_MAXIOV];
122 struct iovec *indirect;
123 struct vring_used_elem *heads;
124 /* Protected by virtqueue mutex. */
125 struct vhost_umem *umem;
128 /* Log write descriptors */
129 void __user *log_base;
130 struct vhost_log *log;
132 /* Ring endianness. Defaults to legacy native endianness.
133 * Set to true when starting a modern virtio device. */
135 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
136 /* Ring endianness requested by userspace for cross-endian support. */
139 u32 busyloop_timeout;
143 struct mm_struct *mm;
145 struct vhost_virtqueue **vqs;
147 struct file *log_file;
148 struct eventfd_ctx *log_ctx;
149 struct llist_head work_list;
150 struct task_struct *worker;
151 struct vhost_umem *umem;
154 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
155 long vhost_dev_set_owner(struct vhost_dev *dev);
156 bool vhost_dev_has_owner(struct vhost_dev *dev);
157 long vhost_dev_check_owner(struct vhost_dev *);
158 struct vhost_umem *vhost_dev_reset_owner_prepare(void);
159 void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
160 void vhost_dev_cleanup(struct vhost_dev *, bool locked);
161 void vhost_dev_stop(struct vhost_dev *);
162 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
163 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
164 int vhost_vq_access_ok(struct vhost_virtqueue *vq);
165 int vhost_log_access_ok(struct vhost_dev *);
167 int vhost_get_vq_desc(struct vhost_virtqueue *,
168 struct iovec iov[], unsigned int iov_count,
169 unsigned int *out_num, unsigned int *in_num,
170 struct vhost_log *log, unsigned int *log_num);
171 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
173 int vhost_vq_init_access(struct vhost_virtqueue *);
174 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
175 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
177 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
178 unsigned int id, int len);
179 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
180 struct vring_used_elem *heads, unsigned count);
181 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
182 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
183 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
184 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
186 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
187 unsigned int log_num, u64 len);
189 #define vq_err(vq, fmt, ...) do { \
190 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
191 if ((vq)->error_ctx) \
192 eventfd_signal((vq)->error_ctx, 1);\
196 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
197 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
198 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
199 (1ULL << VHOST_F_LOG_ALL) |
200 (1ULL << VIRTIO_F_ANY_LAYOUT) |
201 (1ULL << VIRTIO_F_VERSION_1)
204 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
206 return vq->acked_features & (1ULL << bit);
209 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
210 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
215 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
217 return virtio_legacy_is_little_endian() || vq->is_le;
221 /* Memory accessors */
222 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
224 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
227 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
229 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
232 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
234 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
237 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
239 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
242 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
244 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
247 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
249 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);