[PATCH 25/33] virtio: introduce .skip_vhost_migration_log() handler

[Vladimir Sementsov-Ogievskiy]

For vhost user backend migration we'll need to disable memory
logging on the device. Let's prepare a corresponding handler for
the device.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru>
---
 hw/virtio/vhost.c          | 10 ++++++++++
 include/hw/virtio/virtio.h |  2 ++
 2 files changed, 12 insertions(+)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index e7c809400b..0427fc29b2 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1134,6 +1134,16 @@ static int vhost_migration_log(MemoryListener *listener, 
bool enable)
     struct vhost_dev *dev = container_of(listener, struct vhost_dev,
                                          memory_listener);
     int r;
+
+    if (dev->vdev) {
+        VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev->vdev);
+
+        if (vdc->skip_vhost_migration_log &&
+            vdc->skip_vhost_migration_log(dev->vdev)) {
+            return 0;
+        }
+    }
+
     if (enable == dev->log_enabled) {
         return 0;
     }
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 8b9db08ddf..9a4a0a94aa 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -234,6 +234,8 @@ struct VirtioDeviceClass {
     /* May be called even when vdev->vhost_started is false */
     struct vhost_dev *(*get_vhost)(VirtIODevice *vdev);
     void (*toggle_device_iotlb)(VirtIODevice *vdev);
+
+    bool (*skip_vhost_migration_log)(VirtIODevice *vdev);
 };
 
 void virtio_instance_init_common(Object *proxy_obj, void *data,
-- 
2.48.1