VIRTIO

Interfaces for Virtual I/O (VIRTIO) devices. More...

Topics
	Virtqueue Interface
	Virtqueue Interface.

Files
file	virtio.h
	Main header file for Virtio driver API.
file	virtio_config.h
	VIRTIO common definitions based on the specification.

Data Structures
struct	virtio_driver_api
	@driver_ops{VIRTIO} More...

Typedefs
typedef uint16_t(*	virtio_enumerate_queues) (uint16_t queue_idx, uint16_t max_queue_size, void *opaque)
	Callback used during virtqueue enumeration.

Functions
static struct virtq *	virtio_get_virtqueue (const struct device *dev, uint16_t queue_idx)
	Returns virtqueue at given idx.
static void	virtio_notify_virtqueue (const struct device *dev, uint16_t queue_idx)
	Notifies virtqueue.
static void *	virtio_get_device_specific_config (const struct device *dev)
	Returns device specific config.
static bool	virtio_read_device_feature_bit (const struct device *dev, int bit)
	Returns feature bit offered by virtio device.
static int	virtio_write_driver_feature_bit (const struct device *dev, int bit, bool value)
	Sets feature bit.
static int	virtio_commit_feature_bits (const struct device *dev)
	Commits feature bits.
static int	virtio_init_virtqueues (const struct device *dev, uint16_t num_queues, virtio_enumerate_queues cb, void *opaque)
	Initializes virtqueues.
static void	virtio_finalize_init (const struct device *dev)
	Finalizes initialization of the virtio device.
typedef struct virtq *(*	virtio_api_get_virtqueue) (const struct device *dev, uint16_t queue_idx)
	@def_driverbackendgroup{VIRTIO,virtio_interface}
typedef void(*	virtio_api_notify_virtqueue) (const struct device *dev, uint16_t queue_idx)
	Type definition of VIRTIO API function for notifying a virtqueue.
typedef void *(*	virtio_api_get_device_specific_config) (const struct device *dev)
	Type definition of VIRTIO API function for getting the device specific config.
typedef bool(*	virtio_api_read_device_feature_bit) (const struct device *dev, int bit)
	Type definition of VIRTIO API function for reading a device feature bit.
typedef int(*	virtio_api_write_driver_feature_bit) (const struct device *dev, int bit, bool value)
	Type definition of VIRTIO API function for writing a driver feature bit.
typedef int(*	virtio_api_commit_feature_bits) (const struct device *dev)
	Type definition of VIRTIO API function for committing the feature bits.
typedef int(*	virtio_api_init_virtqueues) (const struct device *dev, uint16_t num_queues, virtio_enumerate_queues cb, void *opaque)
	Type definition of VIRTIO API function for initializing the virtqueues.
typedef void(*	virtio_api_finalize_init) (const struct device *dev)
	Type definition of VIRTIO API function for finalizing the initialization.

Detailed Description

Interfaces for Virtual I/O (VIRTIO) devices.

Since

4.2

Version

0.1.0

Typedef Documentation

virtio_api_commit_feature_bits

typedef int(* virtio_api_commit_feature_bits) (const struct device *dev)

#include <virtio.h>

Type definition of VIRTIO API function for committing the feature bits.

See virtio_commit_feature_bits() for argument descriptions.

virtio_api_finalize_init

typedef void(* virtio_api_finalize_init) (const struct device *dev)

#include <virtio.h>

Type definition of VIRTIO API function for finalizing the initialization.

See virtio_finalize_init() for argument descriptions.

virtio_api_get_device_specific_config

typedef void *(* virtio_api_get_device_specific_config) (const struct device *dev)

#include <virtio.h>

Type definition of VIRTIO API function for getting the device specific config.

See virtio_get_device_specific_config() for argument descriptions.

virtio_api_get_virtqueue

typedef struct virtq *(* virtio_api_get_virtqueue) (const struct device *dev, uint16_t queue_idx)

#include <virtio.h>

@def_driverbackendgroup{VIRTIO,virtio_interface}

Type definition of VIRTIO API function for getting a virtqueue. See virtio_get_virtqueue() for argument descriptions.

virtio_api_init_virtqueues

typedef int(* virtio_api_init_virtqueues) (const struct device *dev, uint16_t num_queues, virtio_enumerate_queues cb, void *opaque)

#include <virtio.h>

Type definition of VIRTIO API function for initializing the virtqueues.

See virtio_init_virtqueues() for argument descriptions.

virtio_api_notify_virtqueue

typedef void(* virtio_api_notify_virtqueue) (const struct device *dev, uint16_t queue_idx)

#include <virtio.h>

Type definition of VIRTIO API function for notifying a virtqueue.

See virtio_notify_virtqueue() for argument descriptions.

virtio_api_read_device_feature_bit

typedef bool(* virtio_api_read_device_feature_bit) (const struct device *dev, int bit)

#include <virtio.h>

Type definition of VIRTIO API function for reading a device feature bit.

See virtio_read_device_feature_bit() for argument descriptions.

virtio_api_write_driver_feature_bit

typedef int(* virtio_api_write_driver_feature_bit) (const struct device *dev, int bit, bool value)

#include <virtio.h>

Type definition of VIRTIO API function for writing a driver feature bit.

See virtio_write_driver_feature_bit() for argument descriptions.

virtio_enumerate_queues

typedef uint16_t(* virtio_enumerate_queues) (uint16_t queue_idx, uint16_t max_queue_size, void *opaque)

#include <virtio.h>

Callback used during virtqueue enumeration.

Parameters

queue_idx	index of currently inspected queue
max_queue_size	maximum permitted size of currently inspected queue
opaque	pointer to user provided data

Returns

the size of currently inspected virtqueue we want to set

Function Documentation

virtio_commit_feature_bits()

int virtio_commit_feature_bits ( const struct device * dev )

inlinestatic

#include <virtio.h>

Commits feature bits.

Parameters

dev	virtio device it operates on

Returns

0 on success or negative error code on failure

virtio_finalize_init()

void virtio_finalize_init ( const struct device * dev )

inlinestatic

#include <virtio.h>

Finalizes initialization of the virtio device.

Parameters

dev	virtio device it operates on

virtio_get_device_specific_config()

void * virtio_get_device_specific_config ( const struct device * dev )

inlinestatic

#include <virtio.h>

Returns device specific config.

Parameters

dev	virtio device it operates on

Returns

pointer to the device specific config or NULL if its not present

virtio_get_virtqueue()

struct virtq * virtio_get_virtqueue ( const struct device * dev, uint16_t queue_idx )

inlinestatic

#include <virtio.h>

Returns virtqueue at given idx.

Parameters

dev	virtio device it operates on
queue_idx	index of virtqueue to get

Returns

pointer to virtqueue or NULL if not present

virtio_init_virtqueues()

int virtio_init_virtqueues ( const struct device * dev, uint16_t num_queues, virtio_enumerate_queues cb, void * opaque )

inlinestatic

#include <virtio.h>

Initializes virtqueues.

Parameters

dev	virtio device it operates on
num_queues	number of queues to initialize
cb	callback called for each available virtqueue
opaque	pointer to user provided data that will be passed to the callback

Returns

0 on success or negative error code on failure

virtio_notify_virtqueue()

void virtio_notify_virtqueue ( const struct device * dev, uint16_t queue_idx )

inlinestatic

#include <virtio.h>

Notifies virtqueue.

Note that according to spec 2.7.13.3 the device may access the buffers as soon as the avail->idx is increased, which is done by virtq_add_buffer_chain, so the device may access the buffers even without notifying it with virtio_notify_virtqueue

Parameters

dev	virtio device it operates on
queue_idx	virtqueue to be notified

virtio_read_device_feature_bit()

bool virtio_read_device_feature_bit ( const struct device * dev, int bit )

inlinestatic

#include <virtio.h>

Returns feature bit offered by virtio device.

Parameters

dev	virtio device it operates on
bit	selected bit

Returns

value of the offered feature bit

virtio_write_driver_feature_bit()

int virtio_write_driver_feature_bit ( const struct device * dev, int bit, bool value )

inlinestatic

#include <virtio.h>

Sets feature bit.

Parameters

dev	virtio device it operates on
bit	selected bit
value	bit value to write

Returns

0 on success or negative error code on failure