Re: [Qemu-devel] [PATCH 00/15] qdev: make reset semantics more clear and consistent, reset qbuses under virtio devices

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Dec 17, 2012 at 05:24:35PM +0100, Paolo Bonzini wrote:
> After discussion with mst on the topic of resetting virtio devices,
> here is a series that hopefully clarifies the semantics of bus and
> device resets.
> 
> After this series, there are two kinds of resets:

So just to clarify, what I proposed was this
(on top of my type safety patch). Then
all transports can call virtio_config_reset
when appropriate (e.g. when PA is set to 0).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/virtio.c b/hw/virtio.c
index f40a8c5..e65d7c8 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -554,6 +554,14 @@ void virtio_reset(void *opaque)
     }
 }
 
+/* Device-specific reset through virtio config space.
+ * Reset virtio config and backend child devices if any.
+ */
+void virtio_config_reset(VirtIODevice *vdev)
+{
+    qdev_reset_all(vdev->binding_opaque);
+}
+
 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr)
 {
     uint8_t val;
diff --git a/hw/virtio.h b/hw/virtio.h
index 7c17f7b..e2e57a4 100644
--- a/hw/virtio.h
+++ b/hw/virtio.h
@@ -187,11 +187,12 @@ uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
 void virtio_set_status(VirtIODevice *vdev, uint8_t val);
 void virtio_reset(void *opaque);
+void virtio_config_reset(VirtIODevice *vdev);
 void virtio_update_irq(VirtIODevice *vdev);
 int virtio_set_features(VirtIODevice *vdev, uint32_t val);
 
 void virtio_bind_device(VirtIODevice *vdev, const VirtIOBindings *binding,
                         DeviceState *opaque);
 
 /* Base devices.  */
 typedef struct VirtIOBlkConf VirtIOBlkConf;