[PATCH 4/6] vdpa: add listener_registered

["Eugenio Pérez" <eperezma@redhat.com>]

Check if the listener has been registered or not, so it needs to be
registered again at start.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 include/hw/virtio/vhost-vdpa.h | 6 ++++++
 hw/virtio/vhost-vdpa.c         | 7 ++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index 8f54e5edd4..03ed2f2be3 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -45,6 +45,12 @@ typedef struct vhost_vdpa_shared {
 
     bool iotlb_batch_begin_sent;
 
+    /*
+     * The memory listener has been registered, so DMA maps have been sent to
+     * the device.
+     */
+    bool listener_registered;
+
     /* Vdpa must send shadow addresses as IOTLB key for data queues, not GPA */
     bool shadow_data;
 } VhostVDPAShared;
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index bd4db7ba5f..b08349d57c 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -1331,7 +1331,10 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
                          "IOMMU and try again");
             return -1;
         }
-        memory_listener_register(&v->shared->listener, dev->vdev->dma_as);
+        if (!v->shared->listener_registered) {
+            memory_listener_register(&v->shared->listener, dev->vdev->dma_as);
+            v->shared->listener_registered = true;
+        }
 
         return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
     }
@@ -1351,6 +1354,8 @@ static void vhost_vdpa_reset_status(struct vhost_dev *dev)
     vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
                                VIRTIO_CONFIG_S_DRIVER);
     memory_listener_unregister(&v->shared->listener);
+    v->shared->listener_registered = false;
+
 }
 
 static int vhost_vdpa_set_log_base(struct vhost_dev *dev, uint64_t base,
-- 
2.39.3