Re: [PATCH] vdpa: Allow vDPA to work on big-endian machine

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

On Tue, Feb 11, 2025 at 10:19:23AM -0600, Konstantin Shkolnyy wrote:
> Add .set_vnet_le() function that always returns success, assuming that
> vDPA h/w always implements LE data format. Otherwise, QEMU disables vDPA and
> outputs the message:
> "backend does not support LE vnet headers; falling back on userspace virtio"
> 
> Signed-off-by: Konstantin Shkolnyy <kshk@linux.ibm.com>

Thanks for the patch! Yet something to improve:


> ---
>  net/vhost-vdpa.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 231b45246c..7219aa2eee 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -270,6 +270,11 @@ static bool vhost_vdpa_has_ufo(NetClientState *nc)
>  
>  }
>  
> +static int vhost_vdpa_set_vnet_le(NetClientState *nc, bool is_le)
> +{
> +    return 0;

How about checking is_le is true then?
And add a code comment with an explanation, please.


> +}
> +
>  static bool vhost_vdpa_check_peer_type(NetClientState *nc, ObjectClass *oc,
>                                         Error **errp)
>  {
> @@ -437,6 +442,7 @@ static NetClientInfo net_vhost_vdpa_info = {
>          .cleanup = vhost_vdpa_cleanup,
>          .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
>          .has_ufo = vhost_vdpa_has_ufo,
> +        .set_vnet_le = vhost_vdpa_set_vnet_le,
>          .check_peer_type = vhost_vdpa_check_peer_type,
>          .set_steering_ebpf = vhost_vdpa_set_steering_ebpf,
>  };
> -- 
> 2.34.1