diff options
Diffstat (limited to 'drivers/vhost/vhost.h')
| -rw-r--r-- | drivers/vhost/vhost.h | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h new file mode 100644 index 00000000000..44591ba9b07 --- /dev/null +++ b/drivers/vhost/vhost.h @@ -0,0 +1,161 @@ +#ifndef _VHOST_H +#define _VHOST_H + +#include <linux/eventfd.h> +#include <linux/vhost.h> +#include <linux/mm.h> +#include <linux/mutex.h> +#include <linux/workqueue.h> +#include <linux/poll.h> +#include <linux/file.h> +#include <linux/skbuff.h> +#include <linux/uio.h> +#include <linux/virtio_config.h> +#include <linux/virtio_ring.h> + +struct vhost_device; + +enum { + /* Enough place for all fragments, head, and virtio net header. */ + VHOST_NET_MAX_SG = MAX_SKB_FRAGS + 2, +}; + +/* Poll a file (eventfd or socket) */ +/* Note: there's nothing vhost specific about this structure. */ +struct vhost_poll { + poll_table table; + wait_queue_head_t *wqh; + wait_queue_t wait; + /* struct which will handle all actual work. */ + struct work_struct work; + unsigned long mask; +}; + +void vhost_poll_init(struct vhost_poll *poll, work_func_t func, + unsigned long mask); +void vhost_poll_start(struct vhost_poll *poll, struct file *file); +void vhost_poll_stop(struct vhost_poll *poll); +void vhost_poll_flush(struct vhost_poll *poll); +void vhost_poll_queue(struct vhost_poll *poll); + +struct vhost_log { + u64 addr; + u64 len; +}; + +/* The virtqueue structure describes a queue attached to a device. */ +struct vhost_virtqueue { + struct vhost_dev *dev; + + /* The actual ring of buffers. */ + struct mutex mutex; + unsigned int num; + struct vring_desc __user *desc; + struct vring_avail __user *avail; + struct vring_used __user *used; + struct file *kick; + struct file *call; + struct file *error; + struct eventfd_ctx *call_ctx; + struct eventfd_ctx *error_ctx; + struct eventfd_ctx *log_ctx; + + struct vhost_poll poll; + + /* The routine to call when the Guest pings us, or timeout. */ + work_func_t handle_kick; + + /* Last available index we saw. */ + u16 last_avail_idx; + + /* Caches available index value from user. */ + u16 avail_idx; + + /* Last index we used. */ + u16 last_used_idx; + + /* Used flags */ + u16 used_flags; + + /* Log writes to used structure. */ + bool log_used; + u64 log_addr; + + struct iovec indirect[VHOST_NET_MAX_SG]; + struct iovec iov[VHOST_NET_MAX_SG]; + struct iovec hdr[VHOST_NET_MAX_SG]; + size_t hdr_size; + /* We use a kind of RCU to access private pointer. + * All readers access it from workqueue, which makes it possible to + * flush the workqueue instead of synchronize_rcu. Therefore readers do + * not need to call rcu_read_lock/rcu_read_unlock: the beginning of + * work item execution acts instead of rcu_read_lock() and the end of + * work item execution acts instead of rcu_read_lock(). + * Writers use virtqueue mutex. */ + void *private_data; + /* Log write descriptors */ + void __user *log_base; + struct vhost_log log[VHOST_NET_MAX_SG]; +}; + +struct vhost_dev { + /* Readers use RCU to access memory table pointer + * log base pointer and features. + * Writers use mutex below.*/ + struct vhost_memory *memory; + struct mm_struct *mm; + struct mutex mutex; + unsigned acked_features; + struct vhost_virtqueue *vqs; + int nvqs; + struct file *log_file; + struct eventfd_ctx *log_ctx; +}; + +long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs); +long vhost_dev_check_owner(struct vhost_dev *); +long vhost_dev_reset_owner(struct vhost_dev *); +void vhost_dev_cleanup(struct vhost_dev *); +long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg); +int vhost_vq_access_ok(struct vhost_virtqueue *vq); +int vhost_log_access_ok(struct vhost_dev *); + +unsigned vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *, + struct iovec iov[], unsigned int iov_count, + unsigned int *out_num, unsigned int *in_num, + struct vhost_log *log, unsigned int *log_num); +void vhost_discard_vq_desc(struct vhost_virtqueue *); + +int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); +void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); +void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, + unsigned int head, int len); +void vhost_disable_notify(struct vhost_virtqueue *); +bool vhost_enable_notify(struct vhost_virtqueue *); + +int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, + unsigned int log_num, u64 len); + +int vhost_init(void); +void vhost_cleanup(void); + +#define vq_err(vq, fmt, ...) do { \ + pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ + if ((vq)->error_ctx) \ + eventfd_signal((vq)->error_ctx, 1);\ + } while (0) + +enum { + VHOST_FEATURES = (1 << VIRTIO_F_NOTIFY_ON_EMPTY) | + (1 << VIRTIO_RING_F_INDIRECT_DESC) | + (1 << VHOST_F_LOG_ALL) | + (1 << VHOST_NET_F_VIRTIO_NET_HDR), +}; + +static inline int vhost_has_feature(struct vhost_dev *dev, int bit) +{ + unsigned acked_features = rcu_dereference(dev->acked_features); + return acked_features & (1 << bit); +} + +#endif |