[PATCH v4 3/4] virtio-mmio: add support for configure interrupt

[Cindy Lu <lulu@redhat.com>]

add configure interrupt support for virtio-mmio bus. This
interrupt will working while backend is vhost-vdpa

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 hw/virtio/virtio-mmio.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index e1b5c3b81e..beabd129ef 100644
--- a/hw/virtio/virtio-mmio.c
+++ b/hw/virtio/virtio-mmio.c
@@ -627,12 +627,30 @@ static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
     }
 
     if (vdc->guest_notifier_mask && vdev->use_guest_notifier_mask) {
-        vdc->guest_notifier_mask(vdev, n, !assign);
+        vdc->guest_notifier_mask(vdev, n, !assign, VIRTIO_VQ_VECTOR);
     }
-
     return 0;
 }
+static int virtio_mmio_set_config_notifier(DeviceState *d,  bool assign)
+{
+    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+        VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
 
+    EventNotifier *notifier = virtio_get_config_notifier(vdev);
+    int r = 0;
+    if (assign) {
+        r = event_notifier_init(notifier, 0);
+        virtio_set_config_notifier_fd_handler(vdev, true, false);
+    } else {
+        virtio_set_config_notifier_fd_handler(vdev, false, false);
+        event_notifier_cleanup(notifier);
+    }
+        if (vdc->guest_notifier_mask && vdev->use_guest_notifier_mask) {
+            vdc->guest_notifier_mask(vdev, 0, !assign, VIRTIO_CONFIG_VECTOR);
+    }
+    return r;
+}
 static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
                                            bool assign)
 {
@@ -654,8 +672,15 @@ static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
             goto assign_error;
         }
     }
+   r = virtio_mmio_set_config_notifier(d, assign);
+   if (r < 0) {
+            goto config_assign_error;
+   }
 
     return 0;
+config_assign_error:
+    assert(assign);
+    r = virtio_mmio_set_config_notifier(d, false);
 
 assign_error:
     /* We get here on assignment failure. Recover by undoing for VQs 0 .. n. */
@@ -666,6 +691,7 @@ assign_error:
     return r;
 }
 
+
 static void virtio_mmio_pre_plugged(DeviceState *d, Error **errp)
 {
     VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
-- 
2.21.3