minios: Fix lost events

evtchn_bind_interdomain used to clear any already pending event before
binding a handler, because else the handler may be called before it is
ready. That however leads to missed events, which I had to workaround
for the HVM case.

This changes the semantics of bind_evtchn, and thus of all the
event channel binding functions (bind_virq, evtchn_alloc_unbound,
evtchn_bind_interdomain) into not unmasking the event itself, hence
letting the caller initialize properly before unmasking the port (e.g.
record the port number in an appropriate place).

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>

1 files changed, 1 insertions, 5 deletions

diff --git a/extras/mini-os/events.c b/extras/mini-os/events.c
index 9174f166ed..7c88807889 100644
--- a/extras/mini-os/events.c
+++ b/extras/mini-os/events.c
@@ -87,9 +87,6 @@ evtchn_port_t bind_evtchn(evtchn_port_t port, evtchn_handler_t handler,
 	wmb();
 	ev_actions[port].handler = handler;
 
-	/* Finally unmask the port */
-	unmask_evtchn(port);
-
 	return port;
 }
 
@@ -191,8 +188,7 @@ int evtchn_bind_interdomain(domid_t pal, evtchn_port_t remote_port,
     if (err)
 		return err;
     set_bit(op.local_port,bound_ports);
-	evtchn_port_t port = op.local_port;
-    clear_evtchn(port);	      /* Without, handler gets invoked now! */
+    evtchn_port_t port = op.local_port;
     *local_port = bind_evtchn(port, handler, data);
     return err;
 }