Virtualization - Dec 2021 - [PATCH v2 07/10] vdpa: Add support for returning device configuration information

On Mon, Dec 13, 2021 at 10:43 PM Eli Cohen <elic at nvidia.com>
wrote:
>
> Add netlink attribute to store flags indicating current state of the
> device.
> In addition, introduce a flag to indicate whether control virtqueue is
> used.
>
> This indication can be retrieved by:
>
> vdpa dev config show vdpa-a
> vdpa-a: mac 00:00:00:00:88:88 link up link_announce false max_vq_pairs 1
>         mtu 1500 ctrl_vq yes
I think the cvq is kind of duplicated with the driver features?

Thanks
>
> Signed-off-by: Eli Cohen <elic at nvidia.com>
>
> ----
> V1 -> V2
> Patch was changed to return only an indication of ctrl VQ
> ---
>  drivers/vdpa/vdpa.c       | 17 +++++++++++++++++
>  include/uapi/linux/vdpa.h |  8 ++++++++
>  2 files changed, 25 insertions(+)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index 7b7bef7673b4..130a8d4aeaed 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -787,6 +787,19 @@ static int vdpa_nl_cmd_dev_get_dumpit(struct sk_buff
*msg, struct netlink_callba
>         return msg->len;
>  }
>
> +static int vdpa_dev_net_ctrl_vq_fill(struct vdpa_device *vdev,
> +                                    struct sk_buff *msg,
> +                                    struct virtio_net_config *config,
> +                                    u64 features)
> +{
> +       if (!(features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ)))
> +               return 0;
> +
> +       /* currently the only flag can be returned */
> +       return nla_put_u64_64bit(msg, VDPA_ATTR_DEV_FLAGS,
> +                                BIT_ULL(VDPA_DEV_ATTR_CVQ),
VDPA_ATTR_PAD);
> +}
> +
>  static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev,
>                                        struct sk_buff *msg, u64 features,
>                                        const struct virtio_net_config
*config)
> @@ -805,6 +818,7 @@ static int vdpa_dev_net_config_fill(struct vdpa_device
*vdev, struct sk_buff *ms
>         struct virtio_net_config config = {};
>         u64 features;
>         u16 val_u16;
> +       int err;
>
>         vdpa_get_config(vdev, 0, &config, sizeof(config));
>
> @@ -821,6 +835,9 @@ static int vdpa_dev_net_config_fill(struct vdpa_device
*vdev, struct sk_buff *ms
>                 return -EMSGSIZE;
>
>         features = vdev->config->get_driver_features(vdev);
> +       err = vdpa_dev_net_ctrl_vq_fill(vdev, msg, &config, features);
> +       if (err)
> +               return err;
>
>         return vdpa_dev_net_mq_config_fill(vdev, msg, features,
&config);
>  }
> diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
> index a252f06f9dfd..23b854e3e5e2 100644
> --- a/include/uapi/linux/vdpa.h
> +++ b/include/uapi/linux/vdpa.h
> @@ -20,9 +20,16 @@ enum vdpa_command {
>         VDPA_CMD_DEV_CONFIG_GET,        /* can dump */
>  };
>
> +enum {
> +       VDPA_DEV_ATTR_CVQ,
> +};
> +
>  enum vdpa_attr {
>         VDPA_ATTR_UNSPEC,
>
> +       /* Pad attribute for 64b alignment */
> +       VDPA_ATTR_PAD = VDPA_ATTR_UNSPEC,
> +
>         /* bus name (optional) + dev name together make the parent device
handle */
>         VDPA_ATTR_MGMTDEV_BUS_NAME,             /* string */
>         VDPA_ATTR_MGMTDEV_DEV_NAME,             /* string */
> @@ -34,6 +41,7 @@ enum vdpa_attr {
>         VDPA_ATTR_DEV_MAX_VQS,                  /* u32 */
>         VDPA_ATTR_DEV_MAX_VQ_SIZE,              /* u16 */
>         VDPA_ATTR_DEV_MIN_VQ_SIZE,              /* u16 */
> +       VDPA_ATTR_DEV_FLAGS,                    /* u64 */
>
>         VDPA_ATTR_DEV_NET_CFG_MACADDR,          /* binary */
>         VDPA_ATTR_DEV_NET_STATUS,               /* u8 */
> --
> 2.33.1
>