Re: [Qemu-devel] [PATCH 5/5] virtio-ccw: implement ->device_plugged

[Shannon Zhao]

On 2015/5/4 23:28, Cornelia Huck wrote:
> Let's move operations that are only valid after the backend has been
> realized to a ->device_plugged callback, just as virtio-pci does.
> Also reorder setting up the host feature bits to the sequence used
> by virtio-pci.
> 
> While we're at it, also add a ->device_unplugged callback to stop
> ioeventfd, just to be on the safe side.
> 
> Signed-off-by: Cornelia Huck <address@hidden>
> Message-Id: <address@hidden>

Reviewed-by: Shannon Zhao <address@hidden>

> ---
>  hw/s390x/virtio-ccw.c | 41 ++++++++++++++++++++++++++---------------
>  1 file changed, 26 insertions(+), 15 deletions(-)
> 
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 1c2bd9d..430cc6f 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -652,10 +652,8 @@ static void virtio_ccw_device_realize(VirtioCcwDevice 
> *dev, Error **errp)
>      bool found = false;
>      SubchDev *sch;
>      int num;
> -    DeviceState *parent = DEVICE(dev);
>      Error *err = NULL;
>      VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_GET_CLASS(dev);
> -    VirtIODevice *vdev;
>  
>      sch = g_malloc0(sizeof(SubchDev));
>  
> @@ -778,19 +776,6 @@ static void virtio_ccw_device_realize(VirtioCcwDevice 
> *dev, Error **errp)
>          goto out_err;
>      }
>  
> -    /* device_id is only set after vdev has been realized */
> -    vdev = virtio_ccw_get_vdev(sch);
> -    sch->id.cu_model = vdev->device_id;
> -
> -    /* Only the first 32 feature bits are used. */
> -    dev->host_features[0] = virtio_bus_get_vdev_features(&dev->bus,
> -                                                         
> dev->host_features[0]);
> -
> -    virtio_add_feature(&dev->host_features[0], VIRTIO_F_NOTIFY_ON_EMPTY);
> -    virtio_add_feature(&dev->host_features[0], VIRTIO_F_BAD_FEATURE);
> -
> -    css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid,
> -                          parent->hotplugged, 1);
>      return;
>  
>  out_err:
> @@ -1428,6 +1413,30 @@ static int virtio_ccw_load_config(DeviceState *d, 
> QEMUFile *f)
>      return 0;
>  }
>  
> +/* This is called by virtio-bus just after the device is plugged. */
> +static void virtio_ccw_device_plugged(DeviceState *d)
> +{
> +    VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
> +    SubchDev *sch = dev->sch;
> +
> +    sch->id.cu_model = virtio_bus_get_vdev_id(&dev->bus);
> +
> +    /* Only the first 32 feature bits are used. */
> +    virtio_add_feature(&dev->host_features[0], VIRTIO_F_NOTIFY_ON_EMPTY);
> +    virtio_add_feature(&dev->host_features[0], VIRTIO_F_BAD_FEATURE);
> +    dev->host_features[0] = virtio_bus_get_vdev_features(&dev->bus,
> +                                                         
> dev->host_features[0]);
> +
> +    css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid,
> +                          d->hotplugged, 1);
> +}
> +
> +static void virtio_ccw_device_unplugged(DeviceState *d)
> +{
> +    VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
> +
> +    virtio_ccw_stop_ioeventfd(dev);
> +}
>  /**************** Virtio-ccw Bus Device Descriptions *******************/
>  
>  static Property virtio_ccw_net_properties[] = {
> @@ -1752,6 +1761,8 @@ static void virtio_ccw_bus_class_init(ObjectClass 
> *klass, void *data)
>      k->load_queue = virtio_ccw_load_queue;
>      k->save_config = virtio_ccw_save_config;
>      k->load_config = virtio_ccw_load_config;
> +    k->device_plugged = virtio_ccw_device_plugged;
> +    k->device_unplugged = virtio_ccw_device_unplugged;
>  }
>  
>  static const TypeInfo virtio_ccw_bus_info = {
> 

-- 
Shannon