From b9d1950675c67f10870debe164a226eef64f65d5 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Tue, 18 Mar 2008 11:29:18 +0000 Subject: 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 --- extras/mini-os/blkfront.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) (limited to 'extras/mini-os/blkfront.c') diff --git a/extras/mini-os/blkfront.c b/extras/mini-os/blkfront.c index 3210396b7b..f5cf19cbe5 100644 --- a/extras/mini-os/blkfront.c +++ b/extras/mini-os/blkfront.c @@ -43,7 +43,7 @@ struct blkfront_dev { struct blkif_front_ring ring; grant_ref_t ring_ref; - evtchn_port_t evtchn, local_port; + evtchn_port_t evtchn; blkif_vdev_t handle; char *nodename; @@ -92,14 +92,9 @@ struct blkfront_dev *init_blkfront(char *nodename, uint64_t *sectors, unsigned * dev = malloc(sizeof(*dev)); dev->nodename = strdup(nodename); - evtchn_alloc_unbound_t op; - op.dom = DOMID_SELF; snprintf(path, sizeof(path), "%s/backend-id", nodename); - dev->dom = op.remote_dom = xenbus_read_integer(path); - HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, &op); - clear_evtchn(op.port); /* Without, handler gets invoked now! */ - dev->local_port = bind_evtchn(op.port, blkfront_handler, dev); - dev->evtchn=op.port; + dev->dom = xenbus_read_integer(path); + evtchn_alloc_unbound(dev->dom, blkfront_handler, dev, &dev->evtchn); s = (struct blkif_sring*) alloc_page(); memset(s,0,PAGE_SIZE); @@ -194,6 +189,7 @@ done: snprintf(path, sizeof(path), "%s/feature-flush-cache", dev->backend); dev->flush = xenbus_read_integer(path); } + unmask_evtchn(dev->evtchn); printk("%u sectors of %u bytes\n", dev->sectors, dev->sector_size); printk("**************************\n"); @@ -219,7 +215,7 @@ void shutdown_blkfront(struct blkfront_dev *dev) err = xenbus_printf(XBT_NIL, nodename, "state", "%u", 6); xenbus_wait_for_value(path,"6"); - unbind_evtchn(dev->local_port); + unbind_evtchn(dev->evtchn); free(nodename); free(dev->backend); -- cgit v1.2.3