include/linux/virtio_config.h

Source file repositories/reference/linux-study-clean/include/linux/virtio_config.h

File Facts

System
Linux kernel
Corpus path
include/linux/virtio_config.h
Extension
.h
Size
21904 bytes
Lines
700
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct virtio_shm_region {
	u64 addr;
	u64 len;
};

typedef void vq_callback_t(struct virtqueue *);

/**
 * struct virtqueue_info - Info for a virtqueue passed to find_vqs().
 * @name: virtqueue description. Used mainly for debugging, NULL for
 *        a virtqueue unused by the driver.
 * @callback: A callback to invoke on a used buffer notification.
 *            NULL for a virtqueue that does not need a callback.
 * @ctx: whether to maintain an extra context per virtqueue.
 */
struct virtqueue_info {
	const char *name;
	vq_callback_t *callback;
	bool ctx;
};

/**
 * struct virtio_config_ops - operations for configuring a virtio device
 * Note: Do not assume that a transport implements all of the operations
 *       getting/setting a value as a simple read/write! Generally speaking,
 *       any of @get/@set, @get_status/@set_status, or @get_features/
 *       @finalize_features are NOT safe to be called from an atomic
 *       context.
 * @get: read the value of a configuration field
 *	vdev: the virtio_device
 *	offset: the offset of the configuration field
 *	buf: the buffer to write the field value into.
 *	len: the length of the buffer
 * @set: write the value of a configuration field
 *	vdev: the virtio_device
 *	offset: the offset of the configuration field
 *	buf: the buffer to read the field value from.
 *	len: the length of the buffer
 * @generation: config generation counter (optional)
 *	vdev: the virtio_device
 *	Returns the config generation counter
 * @get_status: read the status byte
 *	vdev: the virtio_device
 *	Returns the status byte
 * @set_status: write the status byte
 *	vdev: the virtio_device
 *	status: the new status byte
 * @reset: reset the device
 *	vdev: the virtio device
 *	After this, status and feature negotiation must be done again
 *	Device must not be reset from its vq/config callbacks, or in
 *	parallel with being added/removed.
 * @find_vqs: find virtqueues and instantiate them.
 *	vdev: the virtio_device
 *	nvqs: the number of virtqueues to find
 *	vqs: on success, includes new virtqueues
 *	vqs_info: array of virtqueue info structures
 *	Returns 0 on success or error status
 * @del_vqs: free virtqueues found by find_vqs().
 * @synchronize_cbs: synchronize with the virtqueue callbacks (optional)
 *      The function guarantees that all memory operations on the
 *      queue before it are visible to the vring_interrupt() that is
 *      called after it.
 *      vdev: the virtio_device
 * @get_features: get the array of feature bits for this device.
 *	vdev: the virtio_device
 *	Returns the first 64 feature bits.
 * @get_extended_features:
 *      vdev: the virtio_device
 *      Returns the first VIRTIO_FEATURES_BITS feature bits (all we currently
 *      need).
 * @finalize_features: confirm what device features we'll be using.
 *	vdev: the virtio_device
 *	This sends the driver feature bits to the device: it can change
 *	the dev->feature bits if it wants.
 *	Note that despite the name this can be called any number of
 *	times.
 *	Returns 0 on success or error status
 * @bus_name: return the bus name associated with the device (optional)
 *	vdev: the virtio_device
 *      This returns a pointer to the bus name a la pci_name from which
 *      the caller can then copy.
 * @set_vq_affinity: set the affinity for a virtqueue (optional).
 * @get_vq_affinity: get the affinity for a virtqueue (optional).
 * @get_shm_region: get a shared memory region based on the index.
 * @disable_vq_and_reset: reset a queue individually (optional).
 *	vq: the virtqueue
 *	Returns 0 on success or error status
 *	disable_vq_and_reset will guarantee that the callbacks are disabled and
 *	synchronized.

Annotation

Implementation Notes