virtio: add start_ioeventfd and stop_ioeventfd to VirtioDeviceClass

Allow customization of the start and stop of ioeventfd.  This will
allow direct start of dataplane without passing through the default
ioeventfd handlers, which in turn allows using the dataplane logic
instead of virtio_add_queue_aio.  It will also enable some code
simplification, because the sole entry point to ioeventfd setup
will be virtio_bus_set_host_notifier.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 10 insertions, 1 deletions

diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h
index f74ef1efd9..aa326e11d9 100644
--- a/include/hw/virtio/virtio-bus.h
+++ b/include/hw/virtio/virtio-bus.h
@@ -132,10 +132,15 @@ static inline VirtIODevice *virtio_bus_get_device(VirtioBusState *bus)
 }
 
 /* Start the ioeventfd. */
-void virtio_bus_start_ioeventfd(VirtioBusState *bus);
+int virtio_bus_start_ioeventfd(VirtioBusState *bus);
 /* Stop the ioeventfd. */
 void virtio_bus_stop_ioeventfd(VirtioBusState *bus);
 /* Switch from/to the generic ioeventfd handler */
 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign);
 
+/* This is temporary.  It is only needed because virtio_bus_set_host_notifier
+ * sets ioeventfd_disabled but we will shortly get rid of it.  */
+int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus,
+                               int n, bool assign, bool set_handler);
+
 #endif /* VIRTIO_BUS_H */
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 52d4b55fa6..27e515118b 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -125,6 +125,8 @@ typedef struct VirtioDeviceClass {
      * must mask in frontend instead.
      */
     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
+    int (*start_ioeventfd)(VirtIODevice *vdev);
+    void (*stop_ioeventfd)(VirtIODevice *vdev);
     /* Saving and loading of a device; trying to deprecate save/load
      * use vmsd for new devices.
      */
@@ -269,6 +271,8 @@ uint16_t virtio_get_queue_index(VirtQueue *vq);
 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
                                                 bool with_irqfd);
+int virtio_device_start_ioeventfd(VirtIODevice *vdev);
+void virtio_device_stop_ioeventfd(VirtIODevice *vdev);
 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
 void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
                                                bool set_handler);