Re: [Qemu-devel] [PATCH V4 3/3] virtio-blk: only clear VIRTIO_F_ANY_LAYOUT for legacy device

[Paolo Bonzini]

On 27/07/2015 11:49, Jason Wang wrote:
> So this patch only clear VIRTIO_F_LAYOUT for legacy device.
> 
> Cc: Stefan Hajnoczi <address@hidden>
> Cc: Kevin Wolf <address@hidden>
> Cc: address@hidden
> Signed-off-by: Jason Wang <address@hidden>
> ---
>  hw/block/virtio-blk.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> index 9acbc3a..1d3f26c 100644
> --- a/hw/block/virtio-blk.c
> +++ b/hw/block/virtio-blk.c
> @@ -731,7 +731,6 @@ static uint64_t virtio_blk_get_features(VirtIODevice 
> *vdev, uint64_t features,
>      virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
>      virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
>      virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
> -    virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT);
>      if (__virtio_has_feature(features, VIRTIO_F_VERSION_1)) {
>          if (s->conf.scsi) {
>              error_setg(errp, "Virtio 1.0 does not support scsi 
> passthrough!");
> @@ -739,6 +738,7 @@ static uint64_t virtio_blk_get_features(VirtIODevice 
> *vdev, uint64_t features,
>          }
>          virtio_add_feature(&features, VIRTIO_F_ANY_LAYOUT);
>      } else {
> +        virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT);
>          virtio_add_feature(&features, VIRTIO_BLK_F_SCSI);
>      }

This patch is unnecessary, since the feature is added back below under
"if (__virtio_has_feature(features, VIRTIO_F_VERSION_1))".

Paolo