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

Paolo Abeni
2025-03-18T08:39:24Z

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