From:   Parav Pandit <parav@nvidia.com>
To:     Si-Wei Liu <si-wei.liu@oracle.com>,
        "mst@redhat.com" <mst@redhat.com>,
        "jasowang@redhat.com" <jasowang@redhat.com>,
        Eli Cohen <elic@nvidia.com>
CC:     "virtualization@lists.linux-foundation.org" 
        <virtualization@lists.linux-foundation.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2 2/7] vdpa: conditionally read STATUS in config space
Thread-Topic: [PATCH v2 2/7] vdpa: conditionally read STATUS in config space
Thread-Index: AQHZNcrt16j1tjEdlESo1L34RWyIYa67GkzA
Date:   Thu, 2 Feb 2023 04:58:31 +0000
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References: <1675207345-22328-1-git-send-email-si-wei.liu@oracle.com>
 <1675207345-22328-3-git-send-email-si-wei.liu@oracle.com>
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> From: Si-Wei Liu <si-wei.liu@oracle.com>
> Sent: Tuesday, January 31, 2023 6:22 PM
>=20
> The spec says:
>     status only exists if VIRTIO_NET_F_STATUS is set
>=20
> Similar to MAC and MTU, vdpa_dev_net_config_fill() should read STATUS
> conditionally depending on the feature bits.
>=20
> Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
> ---
>  drivers/vdpa/vdpa.c | 20 +++++++++++++++-----
>  1 file changed, 15 insertions(+), 5 deletions(-)
>=20
> 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);
>  }
>=20
> +static int vdpa_dev_net_status_config_fill(struct sk_buff *msg, u64 feat=
ures,
> +					   const struct virtio_net_config
> *config) {
> +	u16 val_u16;
> +
> +	if ((features & BIT_ULL(VIRTIO_NET_F_STATUS)) =3D=3D 0)
> +		return 0;
> +
> +	val_u16 =3D __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 =3D {};
>  	u64 features_device;
> -	u16 val_u16;
>=20
>  	vdev->config->get_config(vdev, 0, &config, sizeof(config));
>=20
> -	val_u16 =3D __virtio16_to_cpu(true, config.status);
> -	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16))
> -		return -EMSGSIZE;
> -
>  	features_device =3D vdev->config->get_device_features(vdev);
>=20
>  	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;
>=20
> +	if (vdpa_dev_net_status_config_fill(msg, features_device, &config))
> +		return -EMSGSIZE;
> +
>  	return vdpa_dev_net_mq_config_fill(msg, features_device, &config);  }
>=20
> --
> 1.8.3.1

Reviewed-by: Parav Pandit <parav@nvidia.com>