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-rw-r--r--drivers/vhost/vhost.h161
1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
new file mode 100644
index 000000000000..44591ba9b07a
--- /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