#ifndef _VHOST_H #define _VHOST_H #include <linux/eventfd.h> #include <linux/vhost.h> #include <linux/mm.h> #include <linux/mutex.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> #include <linux/atomic.h> /* This is for zerocopy, used buffer len is set to 1 when lower device DMA * done */ #define VHOST_DMA_DONE_LEN 1 #define VHOST_DMA_CLEAR_LEN 0 struct vhost_device; struct vhost_work; typedef void (*vhost_work_fn_t)(struct vhost_work *work); struct vhost_work { struct list_head node; vhost_work_fn_t fn; wait_queue_head_t done; int flushing; unsigned queue_seq; unsigned done_seq; }; /* 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 vhost_work work; unsigned long mask; struct vhost_dev *dev; }; void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, unsigned long mask, struct vhost_dev *dev); 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; }; struct vhost_virtqueue; struct vhost_ubuf_ref { struct kref kref; wait_queue_head_t wait; struct vhost_virtqueue *vq; }; struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *, bool zcopy); void vhost_ubuf_put(struct vhost_ubuf_ref *); void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *); /* 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. */ vhost_work_fn_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; /* Last used index value we have signalled on */ u16 signalled_used; /* Last used index value we have signalled on */ bool signalled_used_valid; /* Log writes to used structure. */ bool log_used; u64 log_addr; struct iovec iov[UIO_MAXIOV]; /* hdr is used to store the virtio header. * Since each iovec has >= 1 byte length, we never need more than * header length entries to store the header. */ struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)]; struct iovec *indirect; size_t vhost_hlen; size_t sock_hlen; struct vring_used_elem *heads; /* We use a kind of RCU to access private pointer. * All readers access it from worker, which makes it possible to * flush the vhost_work instead of synchronize_rcu. Therefore readers do * not need to call rcu_read_lock/rcu_read_unlock: the beginning of * vhost_work execution acts instead of rcu_read_lock() and the end of * vhost_work execution acts instead of rcu_read_unlock(). * Writers use virtqueue mutex. */ void __rcu *private_data; /* Log write descriptors */ void __user *log_base; struct vhost_log *log; /* vhost zerocopy support fields below: */ /* last used idx for outstanding DMA zerocopy buffers */ int upend_idx; /* first used idx for DMA done zerocopy buffers */ int done_idx; /* an array of userspace buffers info */ struct ubuf_info *ubuf_info; /* Reference counting for outstanding ubufs. * Protected by vq mutex. Writers must also take device mutex. */ struct vhost_ubuf_ref *ubufs; }; struct vhost_dev { /* Readers use RCU to access memory table pointer * log base pointer and features. * Writers use mutex below.*/ struct vhost_memory __rcu *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; spinlock_t work_lock; struct list_head work_list; struct task_struct *worker; }; 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 *); int 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 n); int vhost_init_used(struct vhost_virtqueue *); int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, unsigned count); void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, unsigned int id, int len); void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, struct vring_used_elem *heads, unsigned count); void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, unsigned int log_num, u64 len); void vhost_zerocopy_callback(void *arg); int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq); #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 = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | (1ULL << VIRTIO_RING_F_EVENT_IDX) | (1ULL << VHOST_F_LOG_ALL) | (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) | (1ULL << VIRTIO_NET_F_MRG_RXBUF), }; static inline int vhost_has_feature(struct vhost_dev *dev, int bit) { unsigned acked_features; /* TODO: check that we are running from vhost_worker or dev mutex is * held? */ acked_features = rcu_dereference_index_check(dev->acked_features, 1); return acked_features & (1 << bit); } void vhost_enable_zcopy(int vq); #endif