virtio_dev.h

/*-
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 *
 *   Copyright (c) Cloudbyte Corporation.
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 *       notice, this list of conditions and the following disclaimer in
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 *       from this software without specific prior written permission.
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 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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/*
 * API which presents virtio device accessed over vhost-user protocol through
 * methods resembling file access.
 */

#ifndef VIRTIODEV_H_
#define VIRTIODEV_H_

#include <stddef.h>
#include <sys/types.h>

struct virtio_dev;
typedef struct virtio_dev *dev_handle_t;

enum io_type {
	VIRTIO_TYPE_READ,
	VIRTIO_TYPE_WRITE
};

/*
 * IO descriptor passed as arg when submitting async IO.
 */
typedef struct async_io_desc {
	void *reserved;     // for struct virtio_dev pointer
	enum io_type type;
	void *buf;
	size_t offset;
	size_t nbytes;
	void *user_ctx;
	ssize_t retval;  // code as would have been normally returned by read/write call
} async_io_desc_t;

int libvirtio_dev_init(int mem_mb, int core_mask);
dev_handle_t open_virtio_dev(const char *sock);
size_t virtio_dev_block_size(dev_handle_t hdl);
size_t virtio_dev_blocks_num(dev_handle_t hdl);
void close_virtio_dev(dev_handle_t hdl);
void *virtio_buf_alloc(struct virtio_dev *dev, int size);
void virtio_buf_free(void *buf);

// sync API
int read_virtio_dev(dev_handle_t hdl, void *buf, size_t blk_offset, size_t nblk);
int write_virtio_dev(dev_handle_t hdl, void *buf, size_t blk_offset, size_t nblk);

// async API
int virtio_submit(struct virtio_dev *dev, async_io_desc_t *io_desc);
int virtio_completed(struct virtio_dev *dev, int mincount, int timeout);
async_io_desc_t *virtio_get_completed(struct virtio_dev *dev);

#endif