virtio: postpone the execution of event_notifier_cleanup function

Use the EventNotifier's cleanup callback function to execute the
event_notifier_cleanup function after kvm unregistered the eventfd.

This change supports running the virtio_bus_set_host_notifier
function inside a memory region transaction. Otherwise, a closed
fd is sent to kvm, which results in a failure.

Signed-off-by: Gal Hammer <ghammer@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Gal Hammer 2018-01-14 12:06:55 +02:00 committed by Michael S. Tsirkin
parent f87d72f5c5
commit 4fe6d78b2e
2 changed files with 15 additions and 8 deletions

View file

@ -812,6 +812,10 @@ static void kvm_mem_ioeventfd_del(MemoryListener *listener,
if (r < 0) {
abort();
}
if (e->cleanup) {
e->cleanup(e);
}
}
static void kvm_io_ioeventfd_add(MemoryListener *listener,

View file

@ -256,6 +256,15 @@ bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus)
return k->ioeventfd_assign && k->ioeventfd_enabled(proxy);
}
static void virtio_bus_cleanup_event_notifier(EventNotifier *notifier)
{
/* Test and clear notifier after disabling event,
* in case poll callback didn't have time to run.
*/
virtio_queue_host_notifier_read(notifier);
event_notifier_cleanup(notifier);
}
/*
* This function switches ioeventfd on/off in the device.
* The caller must set or clear the handlers for the EventNotifier.
@ -283,19 +292,13 @@ int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
r = k->ioeventfd_assign(proxy, notifier, n, true);
if (r < 0) {
error_report("%s: unable to assign ioeventfd: %d", __func__, r);
goto cleanup_event_notifier;
virtio_bus_cleanup_event_notifier(notifier);
}
return 0;
} else {
notifier->cleanup = virtio_bus_cleanup_event_notifier;
k->ioeventfd_assign(proxy, notifier, n, false);
}
cleanup_event_notifier:
/* Test and clear notifier after disabling event,
* in case poll callback didn't have time to run.
*/
virtio_queue_host_notifier_read(notifier);
event_notifier_cleanup(notifier);
return r;
}