Using the virtqueue_avail_bytes() function had an unnecessarily
crippling effect on the number of bytes needed by the guest as reported
to the chardev layer in the can_read() callback.
Using the new virtqueue_get_avail_bytes() function will let us advertise
the exact number of bytes we can send to the guest.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
{
VirtQueue *vq = port->ivq;
+ unsigned int bytes;
if (!virtio_queue_ready(vq) ||
!(port->vser->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) ||
if (use_multiport(port->vser) && !port->guest_connected) {
return 0;
}
-
- if (virtqueue_avail_bytes(vq, 4096, 0)) {
- return 4096;
- }
- if (virtqueue_avail_bytes(vq, 1, 0)) {
- return 1;
- }
- return 0;
+ virtqueue_get_avail_bytes(vq, &bytes, NULL);
+ return bytes;
}
static void flush_queued_data_bh(void *opaque)