void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len, unsigned int idx)
{
unsigned int offset;
int i;
trace_virtqueue_fill(vq, elem, len, idx);
offset = 0;
for (i = 0; i < elem->in_num; i++) {
size_t size = MIN(len - offset, elem->in_sg[i].iov_len);
cpu_physical_memory_unmap(elem->in_sg[i].iov_base,
elem->in_sg[i].iov_len,
1, size);
offset += size;
}
for (i = 0; i < elem->out_num; i++)
cpu_physical_memory_unmap(elem->out_sg[i].iov_base,
elem->out_sg[i].iov_len,
0, elem->out_sg[i].iov_len);
idx = (idx + vring_used_idx(vq)) % vq->vring.num;
/* Get a pointer to the next entry in the used ring. */
vring_used_ring_id(vq, idx, elem->index);
vring_used_ring_len(vq, idx, len);
}
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);
}
0, elem->out_sg[i].iov_len);
idx = (idx + vring_used_idx(vq)) % vq->vring.num;
/* Get a pointer to the next entry in the used ring. */
vring_used_ring_id(vq, idx, elem->index);
vring_used_ring_len(vq, idx, len);
}
void virtqueue_flush(VirtQueue *vq, unsigned int count)
{
uint16_t old, new;
/* Make sure buffer is written before we update index. */
smp_wmb();
trace_virtqueue_flush(vq, count);
old = vring_used_idx(vq);
new = old + count;
vring_used_idx_set(vq, new);
vq->inuse -= count;
if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old)))
vq->signalled_used_valid = false;
}
void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len)
{
virtqueue_fill(vq, elem, len, 0);
virtqueue_flush(vq, 1);
}
static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx)
static inline void vring_used_idx_increment(VirtQueue *vq, uint16_t val)
{
target_phys_addr_t pa;
pa = vq->vring.used + offsetof(VRingUsed, idx);
stw_phys(pa, vring_used_idx(vq) + val);
}