From 199ee608f0d08510b5c6c37f31a7fbff211d63c4 Mon Sep 17 00:00:00 2001 From: Luigi Rizzo Date: Tue, 5 Feb 2013 17:53:31 +0100 Subject: 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 Signed-off-by: Stefan Hajnoczi --- net/net.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'net/net.c') diff --git a/net/net.c b/net/net.c index be03a8dd14..a66aa02472 100644 --- a/net/net.c +++ b/net/net.c @@ -441,6 +441,12 @@ void qemu_flush_queued_packets(NetClientState *nc) { 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). -- cgit 1.4.1