vring_desc
size = num * sizeof(struct vring_desc);
vr->desc = (struct vring_desc *) p;
num * sizeof(struct vring_desc));
struct vring_desc *desc;
struct vring_desc *);
struct vring_desc *, uint16_t, struct sglist *, int, int);
size = indirect_size * sizeof(struct vring_desc);
struct vring_desc *indirect)
vq_ring_enqueue_segments(struct virtqueue *vq, struct vring_desc *desc,
struct vring_desc *dp;
struct vring_desc *dp;
dp->len = needed * sizeof(struct vring_desc);
struct vring_desc *dp;
struct vring_desc *indirect;