xref: /kvmtool/include/kvm/virtio.h (revision 39d6af073da0205a2714988fb1ba709a77bbc976)
1*39d6af07SAsias He #ifndef KVM__VIRTIO_H
2*39d6af07SAsias He #define KVM__VIRTIO_H
3*39d6af07SAsias He 
4*39d6af07SAsias He #include <linux/virtio_ring.h>
5*39d6af07SAsias He 
6*39d6af07SAsias He #include <stdint.h>
7*39d6af07SAsias He #include <sys/uio.h>
8*39d6af07SAsias He 
9*39d6af07SAsias He #include "kvm/kvm.h"
10*39d6af07SAsias He 
11*39d6af07SAsias He struct virt_queue {
12*39d6af07SAsias He 	struct vring			vring;
13*39d6af07SAsias He 	uint32_t			pfn;
14*39d6af07SAsias He 	/* The last_avail_idx field is an index to ->ring of struct vring_avail.
15*39d6af07SAsias He 	   It's where we assume the next request index is at.  */
16*39d6af07SAsias He 	uint16_t			last_avail_idx;
17*39d6af07SAsias He };
18*39d6af07SAsias He 
19*39d6af07SAsias He static inline uint16_t virt_queue__pop(struct virt_queue *queue)
20*39d6af07SAsias He {
21*39d6af07SAsias He 	return queue->vring.avail->ring[queue->last_avail_idx++ % queue->vring.num];
22*39d6af07SAsias He }
23*39d6af07SAsias He 
24*39d6af07SAsias He static inline struct vring_desc *virt_queue__get_desc(struct virt_queue *queue, uint16_t desc_ndx)
25*39d6af07SAsias He {
26*39d6af07SAsias He 	return &queue->vring.desc[desc_ndx];
27*39d6af07SAsias He }
28*39d6af07SAsias He 
29*39d6af07SAsias He static inline struct vring_used_elem *virt_queue__get_used_elem(struct virt_queue *queue)
30*39d6af07SAsias He {
31*39d6af07SAsias He 	return &queue->vring.used->ring[queue->vring.used->idx++ % queue->vring.num];
32*39d6af07SAsias He }
33*39d6af07SAsias He 
34*39d6af07SAsias He 
35*39d6af07SAsias He static inline bool virt_queue__available(struct virt_queue *vq)
36*39d6af07SAsias He {
37*39d6af07SAsias He 	return vq->vring.avail->idx !=  vq->last_avail_idx;
38*39d6af07SAsias He }
39*39d6af07SAsias He 
40*39d6af07SAsias He struct vring_used_elem *virt_queue__set_used_elem(struct virt_queue *queue, uint32_t head, uint32_t len);
41*39d6af07SAsias He 
42*39d6af07SAsias He uint16_t virt_queue__get_iov(struct virt_queue *queue, struct iovec iov[], uint16_t *out, uint16_t *in, struct kvm *kvm);
43*39d6af07SAsias He 
44*39d6af07SAsias He #endif /* KVM__VIRTIO_H */
45