static void vring_kick(struct virtqueue *_vq)
{
u16 prev_avail_idx;
struct vring_virtqueue *vq = to_vvq(_vq);
/* Descriptors and available array need to be set before we expose the
* new available array entries. */
mb();
prev_avail_idx = vq->vring.avail->idx - (u16) vq->num_added;
DPrintf(4, ("%s>>> vq->vring.avail->idx %d\n", __FUNCTION__, vq->vring.avail->idx));
vq->num_added = 0;
/* Need to update avail index before checking if we should notify */
mb();
if(vq->use_published_indices) {
if(vring_need_event(vring_last_avail(&vq->vring),
vq->vring.avail->idx,
prev_avail_idx))
vq->notify(&vq->vq);
} else {
if (!(vq->vring.used->flags & VRING_USED_F_NO_NOTIFY))
/* Prod other side to tell it about changes. */
vq->notify(&vq->vq);
}
}
void call_used(void)
{
/* Flush in previous flags write */
/* Barrier D (for pairing) */
smp_mb();
if (!vring_need_event(vring_used_event(&ring),
host.used_idx,
host.called_used_idx))
return;
host.called_used_idx = host.used_idx;
call();
}
void kick_available(void)
{
/* Flush in previous flags write */
/* Barrier C (for pairing) */
smp_mb();
if (!vring_need_event(vring_avail_event(&ring),
guest.avail_idx,
guest.kicked_avail_idx))
return;
guest.kicked_avail_idx = guest.avail_idx;
kick();
}
/**
*
* vq_ring_must_notify_host
*
*/
static int vq_ring_must_notify_host(struct virtqueue *vq)
{
uint16_t new_idx, prev_idx, event_idx;
if (vq->vq_flags & VIRTQUEUE_FLAG_EVENT_IDX) {
new_idx = vq->vq_ring.avail->idx;
prev_idx = new_idx - vq->vq_queued_cnt;
event_idx = vring_avail_event(&vq->vq_ring);
return (vring_need_event(event_idx, new_idx, prev_idx) != 0);
}
return ((vq->vq_ring.used->flags & VRING_USED_F_NO_NOTIFY) == 0);
}
bool virtio_queue_should_signal(struct virtio_queue *vq)
{
u16 old_idx, new_idx, event_idx;
if (!vq->addr) {
return FALSE;
}
old_idx = vq->last_used_signalled;
new_idx = vq->vring.used->idx;
event_idx = vring_used_event(&vq->vring);
if (vring_need_event(event_idx, new_idx, old_idx)) {
vq->last_used_signalled = new_idx;
return TRUE;
}
return FALSE;
}
static bool vring_notify(PVOID unused, VirtQueue *vq)
{
uint16_t old, _new;
bool v;
/* Always notify when queue is empty (when feature acknowledge) */
//if (((vdev->guest_features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) &&
if ((bVirtioF_NotifyOnEmpty &&
!vq->inuse && vring_avail_idx(vq) == vq->last_avail_idx)) {
return TRUE;
}
//if (!(vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX))) {
if (!bUsePublishedIndices) {
return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT);
}
v = vq->signalled_used_valid;
vq->signalled_used_valid = TRUE;
old = vq->signalled_used;
_new = vq->signalled_used = vring_used_idx(vq);
return !v || vring_need_event(vring_used_event(vq), _new, old);
}
