net: fix qemu_flush_queued_packets() in presence of a hub
When frontend and backend are connected through a hub as below
(showing only one direction), and the frontend (or in general, all
output ports of the hub) cannot accept more traffic, the backend
queues packets in queue-A.
When the frontend (or in general, one output port) becomes ready again,
quemu tries to flush packets from queue-B, which is unfortunately empty.
e1000.0 <--[queue B]-- hub0port0(hub)hub0port1 <--[queue A]-- tap.0
To fix this i propose to introduce a new function net_hub_flush()
which is called when trying to flush a queue connected to a hub.
Signed-off-by: Luigi Rizzo <rizzo@iet.unipi.it>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/net/net.c b/net/net.c
index be03a8d..a66aa02 100644
--- a/net/net.c
+++ b/net/net.c
@@ -441,6 +441,12 @@
{
nc->receive_disabled = 0;
+ if (nc->peer && nc->peer->info->type == NET_CLIENT_OPTIONS_KIND_HUBPORT) {
+ if (net_hub_flush(nc->peer)) {
+ qemu_notify_event();
+ }
+ return;
+ }
if (qemu_net_queue_flush(nc->send_queue)) {
/* We emptied the queue successfully, signal to the IO thread to repoll
* the file descriptor (for tap, for example).
