virtq Struct Reference

virtqueue More...

#include <virtqueue.h>

Data Fields
struct k_spinlock	lock
	lock used to synchronize operations on virtqueue
uint16_t	num
	size of virtqueue
struct virtq_desc *	desc
	array with descriptors
struct virtq_avail *	avail
	available ring
struct virtq_used *	used
	used ring
uint16_t	last_used_idx
	last seen idx in used ring, used to determine first descriptor to process after receiving virtqueue interrupt
struct k_stack	free_desc_stack
	Stack containing indexes of free descriptors.
uint16_t	free_desc_n
	amount of free descriptors in the free_desc_stack
struct virtq_receive_callback_entry *	recv_cbs
	array with callbacks invoked after receiving buffers back from the device

Detailed Description

virtqueue

contains structures required for virtqueue operation

Field Documentation

avail

struct virtq_avail* virtq::avail

available ring

desc

struct virtq_desc* virtq::desc

array with descriptors

free_desc_n

uint16_t virtq::free_desc_n

amount of free descriptors in the free_desc_stack

free_desc_stack

struct k_stack virtq::free_desc_stack

Stack containing indexes of free descriptors.

Because virtio devices are not required to use received descriptors in order (see 2.7.9) unless VIRTIO_F_IN_ORDER was offered, we can't use array with descriptors as another ring buffer, always taking next descriptor. This is an auxilary structure to easily determine next free descriptor

last_used_idx

uint16_t virtq::last_used_idx

last seen idx in used ring, used to determine first descriptor to process after receiving virtqueue interrupt

lock

struct k_spinlock virtq::lock

lock used to synchronize operations on virtqueue

num

uint16_t virtq::num

size of virtqueue

recv_cbs

struct virtq_receive_callback_entry* virtq::recv_cbs

array with callbacks invoked after receiving buffers back from the device

used

struct virtq_used* virtq::used

used ring

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The documentation for this struct was generated from the following file:

• include/zephyr/drivers/virtio/virtqueue.h