Re: [PATCH v2 3/8] virtio-net: utilize VirtIOConfigSizeParams & virtio_get_config_size

[Raphael Norwitz]

On Fri, Aug 26, 2022 at 05:32:43PM +0300, Daniil Tatianin wrote:
> Use the new common helper. As an added bonus this also makes use of
> config size sanity checking via the 'max_size' field.
> 
> Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
> ---
>  hw/net/virtio-net.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index dd0d056fde..dfc8dd8562 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -106,6 +106,11 @@ static const VirtIOFeature feature_sizes[] = {
>      {}
>  };
>  
> +static const VirtIOConfigSizeParams cfg_size_params = {

Can we have a zero length virtio-net config size? The both the v1.0 and
v1.1 section 5.1.4 say “The mac address field always exists (though is
only valid if VIRTIO_NET_F_MAC is set)” so we should probably set
min_size to offset_of status?

Otherwise LGTM.

> +    .max_size = sizeof(struct virtio_net_config),
> +    .feature_sizes = feature_sizes
> +};
> +
>  static VirtIONetQueue *virtio_net_get_subqueue(NetClientState *nc)
>  {
>      VirtIONet *n = qemu_get_nic_opaque(nc);
> @@ -3246,8 +3251,7 @@ static void virtio_net_set_config_size(VirtIONet *n, 
> uint64_t host_features)
>  {
>      virtio_add_feature(&host_features, VIRTIO_NET_F_MAC);
>  
> -    n->config_size = virtio_feature_get_config_size(feature_sizes,
> -                                                    host_features);
> +    n->config_size = virtio_get_config_size(&cfg_size_params, host_features);
>  }
>  
>  void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
> -- 
> 2.25.1
>