virtio: move ioeventfd_started flag to VirtioBusState

This simplifies the code and removes the ioeventfd_started
and ioeventfd_set_started callback.  The only difference is
in how virtio-ccw handles an error---it doesn't disable
ioeventfd forever anymore.  It was the only backend to do
so, and if desired this behavior should be implemented in

virtio-bus.c.

Instead of ioeventfd_started, the ioeventfd_assign callback now
determines whether the virtio bus supports host notifiers.

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>

1 files changed, 7 insertions, 10 deletions

diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h
index 4aabec4eb0..f74ef1efd9 100644
--- a/include/hw/virtio/virtio-bus.h
+++ b/include/hw/virtio/virtio-bus.h
@@ -70,17 +70,9 @@ typedef struct VirtioBusClass {
     void (*device_unplugged)(DeviceState *d);
     int (*query_nvectors)(DeviceState *d);
     /*
-     * ioeventfd handling: if the transport implements ioeventfd_started,
-     * it must implement the other ioeventfd callbacks as well
+     * ioeventfd handling: if the transport implements ioeventfd_assign,
+     * it must implement ioeventfd_disabled as well.
      */
-    /* Returns true if the ioeventfd has been started for the device. */
-    bool (*ioeventfd_started)(DeviceState *d);
-    /*
-     * Sets the 'ioeventfd started' state after the ioeventfd has been
-     * started/stopped for the device. err signifies whether an error
-     * had occurred.
-     */
-    void (*ioeventfd_set_started)(DeviceState *d, bool started, bool err);
     /* Returns true if the ioeventfd has been disabled for the device. */
     bool (*ioeventfd_disabled)(DeviceState *d);
     /*
@@ -106,6 +98,11 @@ struct VirtioBusState {
      * or dataplane.
      */
     bool ioeventfd_disabled;
+
+    /*
+     * Set if ioeventfd has been started.
+     */
+    bool ioeventfd_started;
 };
 
 void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp);