[Qemu-devel] [PATCH] virtio: link the rng backend through an alias property

[Qemu-devel] [PATCH] virtio: link the rng backend through an alias property

[Paolo Bonzini]

The virtio-rng backend is currently linked twice, once in
virtio-rng-pci/virtio-rng-ccw and once in virtio-rng-device.  This
causes a double unref of the backend when the parent device is unplugged.

To fix this, make virtio-rng-pci/virtio-rng-ccw use an alias, similar
to what is already being done for the iothread link.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/s390x/virtio-ccw.c  | 6 ++----
 hw/virtio/virtio-pci.c | 7 ++-----
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 1c0d913..ea236c9 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -1544,10 +1544,8 @@ static void virtio_ccw_rng_instance_init(Object *obj)
 
     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
                                 TYPE_VIRTIO_RNG);
-    object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
-                             (Object **)&dev->vdev.conf.rng,
-                             qdev_prop_allow_set_link_before_realize,
-                             OBJ_PROP_LINK_UNREF_ON_RELEASE, NULL);
+    object_property_add_alias(obj, "rng", OBJECT(&dev->vdev),
+                              "rng", &error_abort);
 }
 
 static Property virtio_ccw_rng_properties[] = {
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 542fb9e..e490ade 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1525,11 +1525,8 @@ static void virtio_rng_initfn(Object *obj)
 
     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
                                 TYPE_VIRTIO_RNG);
-    object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
-                             (Object **)&dev->vdev.conf.rng,
-                             qdev_prop_allow_set_link_before_realize,
-                             OBJ_PROP_LINK_UNREF_ON_RELEASE, NULL);
-
+    object_property_add_alias(obj, "rng", OBJECT(&dev->vdev), "rng",
+                              &error_abort);
 }
 
 static const TypeInfo virtio_rng_pci_info = {
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH] virtio: link the rng backend through an alias property

[Gonglei]

On 2014/10/29 7:17, Paolo Bonzini wrote:

> The virtio-rng backend is currently linked twice, once in
> virtio-rng-pci/virtio-rng-ccw and once in virtio-rng-device.  This
> causes a double unref of the backend when the parent device is unplugged.
> 
> To fix this, make virtio-rng-pci/virtio-rng-ccw use an alias, similar
> to what is already being done for the iothread link.
> 

I think s390_virtio_rng should also use an alias for rng backend.

Best regards,
-Gonglei

> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  hw/s390x/virtio-ccw.c  | 6 ++----
>  hw/virtio/virtio-pci.c | 7 ++-----
>  2 files changed, 4 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 1c0d913..ea236c9 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -1544,10 +1544,8 @@ static void virtio_ccw_rng_instance_init(Object *obj)
>  
>      virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
>                                  TYPE_VIRTIO_RNG);
> -    object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
> -                             (Object **)&dev->vdev.conf.rng,
> -                             qdev_prop_allow_set_link_before_realize,
> -                             OBJ_PROP_LINK_UNREF_ON_RELEASE, NULL);
> +    object_property_add_alias(obj, "rng", OBJECT(&dev->vdev),
> +                              "rng", &error_abort);
>  }
>  
>  static Property virtio_ccw_rng_properties[] = {
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 542fb9e..e490ade 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1525,11 +1525,8 @@ static void virtio_rng_initfn(Object *obj)
>  
>      virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
>                                  TYPE_VIRTIO_RNG);
> -    object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
> -                             (Object **)&dev->vdev.conf.rng,
> -                             qdev_prop_allow_set_link_before_realize,
> -                             OBJ_PROP_LINK_UNREF_ON_RELEASE, NULL);
> -
> +    object_property_add_alias(obj, "rng", OBJECT(&dev->vdev), "rng",
> +                              &error_abort);
>  }
>  
>  static const TypeInfo virtio_rng_pci_info = {