RE: [PATCH V2 2/3] vdpa_sim_net: support feature provisioning

[Eli Cohen]

> From: Jason Wang <jasowang@xxxxxxxxxx>
> Sent: Thursday, 22 September 2022 5:43
> To: mst@xxxxxxxxxx; jasowang@xxxxxxxxxx
> Cc: Eli Cohen <elic@xxxxxxxxxx>; si-wei.liu@xxxxxxxxxx; Parav Pandit
> <parav@xxxxxxxxxx>; wuzongyong@xxxxxxxxxxxxxxxxx;
> virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> eperezma@xxxxxxxxxx; lingshan.zhu@xxxxxxxxx; gdawar@xxxxxxxxxx;
> lulu@xxxxxxxxxx; xieyongji@xxxxxxxxxxxxx
> Subject: [PATCH V2 2/3] vdpa_sim_net: support feature provisioning
> 
> This patch implements features provisioning for vdpa_sim_net.
> 
> 1) validating the provisioned features to be a subset of the parent
>    features.
> 2) clearing the features that is not wanted by the userspace
> 
> For example:
> 
> # vdpa mgmtdev show
> vdpasim_net:
>   supported_classes net
>   max_supported_vqs 3
>   dev_features MTU MAC CTRL_VQ CTRL_MAC_ADDR ANY_LAYOUT
> VERSION_1 ACCESS_PLATFORM
> 
> 1) provision vDPA device with all features that are supported by the
>    net simulator
> 
> # vdpa dev add name dev1 mgmtdev vdpasim_net
> # vdpa dev config show
> dev1: mac 00:00:00:00:00:00 link up link_announce false mtu 1500
>   negotiated_features MTU MAC CTRL_VQ CTRL_MAC_ADDR VERSION_1
> ACCESS_PLATFORM
> 
> 2) provision vDPA device with a subset of the features
> 
> # vdpa dev add name dev1 mgmtdev vdpasim_net device_features
> 0x300020000

How about "features_mask" instead of "device_features"? Could avoid confusion.

> # vdpa dev config show
> dev1: mac 00:00:00:00:00:00 link up link_announce false mtu 1500
>   negotiated_features CTRL_VQ VERSION_1 ACCESS_PLATFORM
> 
> Reviewed-by: Eli Cohen <elic@xxxxxxxxxx>
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> ---
>  drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> index 886449e88502..a9ba02be378b 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
> @@ -254,6 +254,14 @@ static int vdpasim_net_dev_add(struct
> vdpa_mgmt_dev *mdev, const char *name,
>  	dev_attr.work_fn = vdpasim_net_work;
>  	dev_attr.buffer_size = PAGE_SIZE;
> 
> +	if (config->mask & BIT_ULL(VDPA_ATTR_DEV_FEATURES)) {
> +		if (config->device_features &
> +		    ~dev_attr.supported_features)
> +			return -EINVAL;
> +		dev_attr.supported_features &=
> +			 config->device_features;
> +	}
> +
>  	simdev = vdpasim_create(&dev_attr);
>  	if (IS_ERR(simdev))
>  		return PTR_ERR(simdev);
> @@ -294,7 +302,8 @@ static struct vdpa_mgmt_dev mgmt_dev = {
>  	.id_table = id_table,
>  	.ops = &vdpasim_net_mgmtdev_ops,
>  	.config_attr_mask = (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR |
> -			     1 << VDPA_ATTR_DEV_NET_CFG_MTU),
> +			     1 << VDPA_ATTR_DEV_NET_CFG_MTU |
> +		             1 << VDPA_ATTR_DEV_FEATURES),
>  	.max_supported_vqs = VDPASIM_NET_VQ_NUM,
>  	.supported_features = VDPASIM_NET_FEATURES,
>  };
> --
> 2.25.1