The host notifier rework tried both to unify host notifiers across
transports and plug a possible hole during host notifier
re-assignment. Unfortunately, this meant a change in semantics that
breaks vhost and iSCSI+dataplane.
As the minimal fix, keep the common host notifier code but revert
to the old semantics so that we have time to figure out the proper
fix.
Fixes: 6798e245a3 ("virtio-bus: common ioeventfd infrastructure")
Reported-by: Peter Lieven <address@hidden>
Reported-by: Jason Wang <address@hidden>
Reported-by: Marc-André Lureau <address@hidden>
Signed-off-by: Cornelia Huck <address@hidden>
---
hw/virtio/virtio-bus.c | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)
diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
index 1313760..a85b7c8 100644
--- a/hw/virtio/virtio-bus.c
+++ b/hw/virtio/virtio-bus.c
@@ -176,8 +176,8 @@ static int set_host_notifier_internal(DeviceState *proxy,
VirtioBusState *bus,
return r;
}
} else {
- virtio_queue_set_host_notifier_fd_handler(vq, false, false);
k->ioeventfd_assign(proxy, notifier, n, assign);
+ virtio_queue_set_host_notifier_fd_handler(vq, false, false);
event_notifier_cleanup(notifier);
}
return r;
@@ -251,31 +251,25 @@ int virtio_bus_set_host_notifier(VirtioBusState *bus, int
n, bool assign)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
- VirtIODevice *vdev = virtio_bus_get_device(bus);
- VirtQueue *vq = virtio_get_queue(vdev, n);
if (!k->ioeventfd_started) {
return -ENOSYS;
}
+ k->ioeventfd_set_disabled(proxy, assign);
if (assign) {
/*
* Stop using the generic ioeventfd, we are doing eventfd handling
* ourselves below
+ *
+ * FIXME: We should just switch the handler and not deassign the
+ * ioeventfd.
+ * Otherwise, there's a window where we don't have an
+ * ioeventfd and we may end up with a notification where
+ * we don't expect one.
*/
- k->ioeventfd_set_disabled(proxy, true);
- }
- /*
- * Just switch the handler, don't deassign the ioeventfd.
- * Otherwise, there's a window where we don't have an
- * ioeventfd and we may end up with a notification where
- * we don't expect one.
- */
- virtio_queue_set_host_notifier_fd_handler(vq, assign, !assign);
- if (!assign) {
- /* Use generic ioeventfd handler again. */
- k->ioeventfd_set_disabled(proxy, false);
+ virtio_bus_stop_ioeventfd(bus);
}
- return 0;
+ return set_host_notifier_internal(proxy, bus, n, assign, false);
}
static char *virtio_bus_get_dev_path(DeviceState *dev)