Re: [PATCH net-next v7 3/9] net: devmem: TCP tx netlink api

[Paolo Abeni <pabeni@redhat.com>]

On 3/8/25 10:40 PM, Mina Almasry wrote:
> From: Stanislav Fomichev <sdf@fomichev.me>
> 
> Add bind-tx netlink call to attach dmabuf for TX; queue is not
> required, only ifindex and dmabuf fd for attachment.
> 
> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
> Signed-off-by: Mina Almasry <almasrymina@google.com>
> 
> ---
> 
> v3:
> - Fix ynl-regen.sh error (Simon).
> 
> ---
>  Documentation/netlink/specs/netdev.yaml | 12 ++++++++++++
>  include/uapi/linux/netdev.h             |  1 +
>  net/core/netdev-genl-gen.c              | 13 +++++++++++++
>  net/core/netdev-genl-gen.h              |  1 +
>  net/core/netdev-genl.c                  |  6 ++++++
>  tools/include/uapi/linux/netdev.h       |  1 +
>  6 files changed, 34 insertions(+)
> 
> diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
> index 36f1152bfac3..e560b05eb528 100644
> --- a/Documentation/netlink/specs/netdev.yaml
> +++ b/Documentation/netlink/specs/netdev.yaml
> @@ -743,6 +743,18 @@ operations:
>              - defer-hard-irqs
>              - gro-flush-timeout
>              - irq-suspend-timeout
> +    -
> +      name: bind-tx
> +      doc: Bind dmabuf to netdev for TX
> +      attribute-set: dmabuf
> +      do:
> +        request:
> +          attributes:
> +            - ifindex
> +            - fd
> +        reply:
> +          attributes:
> +            - id
>  
>  kernel-family:
>    headers: [ "linux/list.h"]
> diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
> index 7600bf62dbdf..7eb9571786b8 100644
> --- a/include/uapi/linux/netdev.h
> +++ b/include/uapi/linux/netdev.h
> @@ -219,6 +219,7 @@ enum {
>  	NETDEV_CMD_QSTATS_GET,
>  	NETDEV_CMD_BIND_RX,
>  	NETDEV_CMD_NAPI_SET,
> +	NETDEV_CMD_BIND_TX,
>  
>  	__NETDEV_CMD_MAX,
>  	NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
> diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
> index 996ac6a449eb..f27608d6301c 100644
> --- a/net/core/netdev-genl-gen.c
> +++ b/net/core/netdev-genl-gen.c
> @@ -99,6 +99,12 @@ static const struct nla_policy netdev_napi_set_nl_policy[NETDEV_A_NAPI_IRQ_SUSPE
>  	[NETDEV_A_NAPI_IRQ_SUSPEND_TIMEOUT] = { .type = NLA_UINT, },
>  };
>  
> +/* NETDEV_CMD_BIND_TX - do */
> +static const struct nla_policy netdev_bind_tx_nl_policy[NETDEV_A_DMABUF_FD + 1] = {
> +	[NETDEV_A_DMABUF_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
> +	[NETDEV_A_DMABUF_FD] = { .type = NLA_U32, },
> +};
> +
>  /* Ops table for netdev */
>  static const struct genl_split_ops netdev_nl_ops[] = {
>  	{
> @@ -190,6 +196,13 @@ static const struct genl_split_ops netdev_nl_ops[] = {
>  		.maxattr	= NETDEV_A_NAPI_IRQ_SUSPEND_TIMEOUT,
>  		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
>  	},
> +	{
> +		.cmd		= NETDEV_CMD_BIND_TX,
> +		.doit		= netdev_nl_bind_tx_doit,
> +		.policy		= netdev_bind_tx_nl_policy,
> +		.maxattr	= NETDEV_A_DMABUF_FD,
> +		.flags		= GENL_CMD_CAP_DO,
> +	},
>  };
>  
>  static const struct genl_multicast_group netdev_nl_mcgrps[] = {
> diff --git a/net/core/netdev-genl-gen.h b/net/core/netdev-genl-gen.h
> index e09dd7539ff2..c1fed66e92b9 100644
> --- a/net/core/netdev-genl-gen.h
> +++ b/net/core/netdev-genl-gen.h
> @@ -34,6 +34,7 @@ int netdev_nl_qstats_get_dumpit(struct sk_buff *skb,
>  				struct netlink_callback *cb);
>  int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info);
>  int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info);
> +int netdev_nl_bind_tx_doit(struct sk_buff *skb, struct genl_info *info);
>  
>  enum {
>  	NETDEV_NLGRP_MGMT,
> diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
> index 2b774183d31c..6e5f2de4d947 100644
> --- a/net/core/netdev-genl.c
> +++ b/net/core/netdev-genl.c
> @@ -931,6 +931,12 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info)
>  	return err;
>  }
>  
> +/* stub */
> +int netdev_nl_bind_tx_doit(struct sk_buff *skb, struct genl_info *info)
> +{
> +	return 0;
> +}
> +
>  void netdev_nl_sock_priv_init(struct list_head *priv)
>  {
>  	INIT_LIST_HEAD(priv);

I'm sorry, but this chunck does not apply cleanly anymore.

Please rebase.

Disclaimer: unfortunately I must note that due to the long backlog
pending and the upcoming merge window, I'm unsure I'll be able to
process the next revision before the net-next closing.

Thanks.

Paolo