> ============================================================================
> And as a part of handle output for kick in the qemu side I am simply calling "virtio_notify"
> static void virtio_sample_handle_output(VirtIODevice *vdev, VirtQueue *vq)
> {
> printf("Function = %s, Line = %d\n",__FUNCTION__,__LINE__);
> virtio_notify(vdev, vq);
> }
>
> Kick is working fine as I am landing in Qemu when making that call, However virtio_notify is not resulting in my callback invocation registered as part find_vq.
> Do you see any missing parts here?
>
I was playing a bit today with my own virtio driver (I have locally
applied my PCI ID patch) and I bumped into your problem
for a few minutes. I think what you are missing is that your queue is
empty and since you probably haven't negotiated the
VIRTIO_F_NOTIFY_ON_EMPTY feature, you are falling victim of this code in qemu:
hw/virtio.c:669
void virtio_notify(VirtIODevice *vdev, VirtQueue *vq)
{
/* Always notify when queue is empty (when feature acknowledge) */
if ((vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT) &&
(!(vdev->features & (1 << VIRTIO_F_NOTIFY_ON_EMPTY)) ||
(vq->inuse || vring_avail_idx(vq) != vq->last_avail_idx)))
return;
^^^^^^^^
This is why you are not getting your interrupt
vdev->isr |= 0x01;
virtio_update_irq(vdev);
}
HTH,
Pantelis
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