Commit 3efd7ab4 authored by Mina Almasry's avatar Mina Almasry Committed by Jakub Kicinski
Browse files

net: netdev netlink api to bind dma-buf to a net device 



API takes the dma-buf fd as input, and binds it to the netdevice. The
user can specify the rx queues to bind the dma-buf to.

Suggested-by: default avatarStanislav Fomichev <sdf@fomichev.me>
Signed-off-by: default avatarMina Almasry <almasrymina@google.com>
Reviewed-by: default avatarDonald Hunter <donald.hunter@gmail.com>
Reviewed-by: default avatarJakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20240910171458.219195-3-almasrymina@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7c88f865

Documentation/netlink/specs/netdev.yaml

+47 −0
Original line number Diff line number Diff line
@@ -457,6 +457,39 @@ attribute-sets: 
          Number of times driver re-started accepting send

          requests to this queue from the stack.

        type: uint

  -

    name: queue-id

    subset-of: queue

    attributes:

      -

        name: id

      -

        name: type

  -

    name: dmabuf

    attributes:

      -

        name: ifindex

        doc: netdev ifindex to bind the dmabuf to.

        type: u32

        checks:

          min: 1

      -

        name: queues

        doc: receive queues to bind the dmabuf to.

        type: nest

        nested-attributes: queue-id

        multi-attr: true

      -

        name: fd

        doc: dmabuf file descriptor to bind.

        type: u32

      -

        name: id

        doc: id of the dmabuf binding

        type: u32

        checks:

          min: 1



operations:

  list:
@@ -619,6 +652,20 @@ operations: 
            - rx-bytes

            - tx-packets

            - tx-bytes

    -

      name: bind-rx

      doc: Bind dmabuf to netdev

      attribute-set: dmabuf

      flags: [ admin-perm ]

      do:

        request:

          attributes:

            - ifindex

            - fd

            - queues

        reply:

          attributes:

            - id



mcast-groups:

  list:

include/uapi/linux/netdev.h

+11 −0
Original line number Diff line number Diff line
@@ -173,6 +173,16 @@ enum { 
	NETDEV_A_QSTATS_MAX = (__NETDEV_A_QSTATS_MAX - 1)

};



enum {

	NETDEV_A_DMABUF_IFINDEX = 1,

	NETDEV_A_DMABUF_QUEUES,

	NETDEV_A_DMABUF_FD,

	NETDEV_A_DMABUF_ID,



	__NETDEV_A_DMABUF_MAX,

	NETDEV_A_DMABUF_MAX = (__NETDEV_A_DMABUF_MAX - 1)

};



enum {

	NETDEV_CMD_DEV_GET = 1,

	NETDEV_CMD_DEV_ADD_NTF,
@@ -186,6 +196,7 @@ enum { 
	NETDEV_CMD_QUEUE_GET,

	NETDEV_CMD_NAPI_GET,

	NETDEV_CMD_QSTATS_GET,

	NETDEV_CMD_BIND_RX,



	__NETDEV_CMD_MAX,

	NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)

net/core/netdev-genl-gen.c

+19 −0
Original line number Diff line number Diff line
@@ -27,6 +27,11 @@ const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFIND 
	[NETDEV_A_PAGE_POOL_IFINDEX] = NLA_POLICY_FULL_RANGE(NLA_U32, &netdev_a_page_pool_ifindex_range),

};



const struct nla_policy netdev_queue_id_nl_policy[NETDEV_A_QUEUE_TYPE + 1] = {

	[NETDEV_A_QUEUE_ID] = { .type = NLA_U32, },

	[NETDEV_A_QUEUE_TYPE] = NLA_POLICY_MAX(NLA_U32, 1),

};



/* NETDEV_CMD_DEV_GET - do */

static const struct nla_policy netdev_dev_get_nl_policy[NETDEV_A_DEV_IFINDEX + 1] = {

	[NETDEV_A_DEV_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
@@ -74,6 +79,13 @@ static const struct nla_policy netdev_qstats_get_nl_policy[NETDEV_A_QSTATS_SCOPE 
	[NETDEV_A_QSTATS_SCOPE] = NLA_POLICY_MASK(NLA_UINT, 0x1),

};



/* NETDEV_CMD_BIND_RX - do */

static const struct nla_policy netdev_bind_rx_nl_policy[NETDEV_A_DMABUF_FD + 1] = {

	[NETDEV_A_DMABUF_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),

	[NETDEV_A_DMABUF_FD] = { .type = NLA_U32, },

	[NETDEV_A_DMABUF_QUEUES] = NLA_POLICY_NESTED(netdev_queue_id_nl_policy),

};



/* Ops table for netdev */

static const struct genl_split_ops netdev_nl_ops[] = {

	{
@@ -151,6 +163,13 @@ static const struct genl_split_ops netdev_nl_ops[] = { 
		.maxattr	= NETDEV_A_QSTATS_SCOPE,

		.flags		= GENL_CMD_CAP_DUMP,

	},

	{

		.cmd		= NETDEV_CMD_BIND_RX,

		.doit		= netdev_nl_bind_rx_doit,

		.policy		= netdev_bind_rx_nl_policy,

		.maxattr	= NETDEV_A_DMABUF_FD,

		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,

	},

};



static const struct genl_multicast_group netdev_nl_mcgrps[] = {

net/core/netdev-genl-gen.h

+2 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 


/* Common nested types */

extern const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFINDEX + 1];

extern const struct nla_policy netdev_queue_id_nl_policy[NETDEV_A_QUEUE_TYPE + 1];



int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info);

int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
@@ -30,6 +31,7 @@ int netdev_nl_napi_get_doit(struct sk_buff *skb, struct genl_info *info); 
int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);

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);



enum {

	NETDEV_NLGRP_MGMT,

net/core/netdev-genl.c

+6 −0
Original line number Diff line number Diff line
@@ -723,6 +723,12 @@ int netdev_nl_qstats_get_dumpit(struct sk_buff *skb, 
	return err;

}



/* Stub */

int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info)

{

	return 0;

}



static int netdev_genl_netdevice_event(struct notifier_block *nb,

				       unsigned long event, void *ptr)

{