Re: [Qemu-devel] [PATCH v1] virtio-scsi: fix object check failure

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

On Wed, Jun 18, 2014 at 11:32:33PM +0800, Ming Lei wrote:
> In case of vhost-scsi, the object type of VirtIODevice isn't
> VirtIOSCSI, so use the cast trick to fix the problem like
> in virtio_scsi_handle_cmd().
> 
> Also 'events_dropped' need to be accessed in the path,

in which path?

> so
> move it into VirtIOSCSICommon.
> 
> Cc: qemu-stable@nongnu.org
> Cc: Anthony Liguori <aliguori@amazon.com>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Ming Lei <ming.lei@canonical.com>
> ---
>  hw/scsi/virtio-scsi.c           |   14 ++++++++------
>  include/hw/virtio/virtio-scsi.h |    3 ++-
>  2 files changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
> index b0d7517..081c226 100644
> --- a/hw/scsi/virtio-scsi.c
> +++ b/hw/scsi/virtio-scsi.c
> @@ -461,7 +461,7 @@ static void virtio_scsi_reset(VirtIODevice *vdev)
>  
>      vs->sense_size = VIRTIO_SCSI_SENSE_SIZE;
>      vs->cdb_size = VIRTIO_SCSI_CDB_SIZE;
> -    s->events_dropped = false;
> +    vs->events_dropped = false;
>  }
>  
>  /* The device does not have anything to save beyond the virtio data.
> @@ -499,7 +499,7 @@ static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
>      }
>  
>      if (!req) {
> -        s->events_dropped = true;
> +        vs->events_dropped = true;
>          return;
>      }
>  
> @@ -507,9 +507,9 @@ static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
>          virtio_scsi_bad_req();
>      }
>  
> -    if (s->events_dropped) {
> +    if (vs->events_dropped) {
>          event |= VIRTIO_SCSI_T_EVENTS_MISSED;
> -        s->events_dropped = false;
> +        vs->events_dropped = false;
>      }
>  
>      in_size = req->elem.in_sg[0].iov_len;
> @@ -538,9 +538,11 @@ static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
>  
>  static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
>  {
> -    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
> +    /* use non-QOM casts in the data path */
> +    VirtIOSCSI *s = (VirtIOSCSI *)vdev;
> +    VirtIOSCSICommon *vs = &s->parent_obj;
>  
> -    if (s->events_dropped) {
> +    if (vs->events_dropped) {
>          virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
>      }
>  }
> diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
> index 367afc6..e60a44a 100644
> --- a/include/hw/virtio/virtio-scsi.h
> +++ b/include/hw/virtio/virtio-scsi.h
> @@ -164,6 +164,8 @@ typedef struct VirtIOSCSICommon {
>      VirtQueue *ctrl_vq;
>      VirtQueue *event_vq;
>      VirtQueue **cmd_vqs;
> +
> +    bool events_dropped;
>  } VirtIOSCSICommon;
>  
>  typedef struct {
> @@ -171,7 +173,6 @@ typedef struct {
>  
>      SCSIBus bus;
>      int resetting;
> -    bool events_dropped;
>  } VirtIOSCSI;
>  
>  #define DEFINE_VIRTIO_SCSI_PROPERTIES(_state, _conf_field)                     \
> -- 
> 1.7.9.5