From 0830c96d70b24ee76864f4e164b164bb43f24f09 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Thu, 30 Jun 2016 17:31:42 +0200 Subject: virtio: revert host notifiers to old semantics MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reported-by: Jason Wang Reported-by: Marc-André Lureau Signed-off-by: Cornelia Huck Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Tested-by: Marc-André Lureau Reviewed-by: Jason Wang Tested-by: Jason Wang Tested-by: Peter Lieven --- 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 131376027b..a85b7c8abe 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) -- cgit v1.2.3