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

From: Eli Cohen
Date: Thu Sep 22 2022 - 01:14:05 EST


> 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