RE: [PATCH v2 2/7] vdpa: conditionally read STATUS in config space

[Parav Pandit]

> From: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
> Sent: Tuesday, January 31, 2023 6:22 PM
> 
> The spec says:
>     status only exists if VIRTIO_NET_F_STATUS is set
> 
> Similar to MAC and MTU, vdpa_dev_net_config_fill() should read STATUS
> conditionally depending on the feature bits.
> 
> Signed-off-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
> ---
>  drivers/vdpa/vdpa.c | 20 +++++++++++++++-----
>  1 file changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c index
> 3a82ca78..21c8aa3 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -843,18 +843,25 @@ static int vdpa_dev_net_mac_config_fill(struct
> sk_buff *msg, u64 features,
>  			sizeof(config->mac), config->mac);
>  }
> 
> +static int vdpa_dev_net_status_config_fill(struct sk_buff *msg, u64 features,
> +					   const struct virtio_net_config
> *config) {
> +	u16 val_u16;
> +
> +	if ((features & BIT_ULL(VIRTIO_NET_F_STATUS)) == 0)
> +		return 0;
> +
> +	val_u16 = __virtio16_to_cpu(true, config->status);
> +	return nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16); }
> +
>  static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff
> *msg)  {
>  	struct virtio_net_config config = {};
>  	u64 features_device;
> -	u16 val_u16;
> 
>  	vdev->config->get_config(vdev, 0, &config, sizeof(config));
> 
> -	val_u16 = __virtio16_to_cpu(true, config.status);
> -	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16))
> -		return -EMSGSIZE;
> -
>  	features_device = vdev->config->get_device_features(vdev);
> 
>  	if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_FEATURES,
> features_device, @@ -867,6 +874,9 @@ static int
> vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms
>  	if (vdpa_dev_net_mac_config_fill(msg, features_device, &config))
>  		return -EMSGSIZE;
> 
> +	if (vdpa_dev_net_status_config_fill(msg, features_device, &config))
> +		return -EMSGSIZE;
> +
>  	return vdpa_dev_net_mq_config_fill(msg, features_device, &config);  }
> 
> --
> 1.8.3.1

Reviewed-by: Parav Pandit <parav@xxxxxxxxxx>