Thu, Feb 05, 2026 at 03:28:29PM +0100, [email protected] wrote:
>From: Or Har-Toov <[email protected]>
>
>Add support for userspace to query resources registered on devlink
>ports, allowing drivers to expose per-port resource limits and usage.
>
>Example output:
>
> $ devlink port resource show
> pci/0000:03:00.0/196608:
> name max_SFs size 20 unit entry
> pci/0000:03:00.1/262144:
> name max_SFs size 20 unit entry
>
> $ devlink port resource show pci/0000:03:00.0/196608
> pci/0000:03:00.0/196608:
> name max_SFs size 20 unit entry
>
>Signed-off-by: Or Har-Toov <[email protected]>
>Reviewed-by: Shay Drori <[email protected]>
>Signed-off-by: Tariq Toukan <[email protected]>
>---
> Documentation/netlink/specs/devlink.yaml | 23 ++++++
> include/uapi/linux/devlink.h | 3 +
> net/devlink/netlink.c | 2 +-
> net/devlink/netlink_gen.c | 32 ++++++-
> net/devlink/netlink_gen.h | 6 +-
> net/devlink/resource.c | 101 +++++++++++++++++++++++
> 6 files changed, 164 insertions(+), 3 deletions(-)
>
>diff --git a/Documentation/netlink/specs/devlink.yaml
>b/Documentation/netlink/specs/devlink.yaml
>index 837112da6738..0290db1b8393 100644
>--- a/Documentation/netlink/specs/devlink.yaml
>+++ b/Documentation/netlink/specs/devlink.yaml
>@@ -2336,3 +2336,26 @@ operations:
> - bus-name
> - dev-name
> - port-index
>+
>+ -
>+ name: port-resource-get
>+ doc: Get port resources.
>+ attribute-set: devlink
>+ dont-validate: [strict]
>+ do:
>+ pre: devlink-nl-pre-doit-port
>+ post: devlink-nl-post-doit
>+ request:
>+ value: 85
>+ attributes: *port-id-attrs
>+ reply: &port-resource-get-reply
>+ value: 85
>+ attributes:
>+ - bus-name
>+ - dev-name
>+ - port-index
>+ - resource-list
>+ dump:
>+ request:
>+ attributes: *dev-id-attrs
>+ reply: *port-resource-get-reply
>diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
>index e7d6b6d13470..1cabd1f6cba0 100644
>--- a/include/uapi/linux/devlink.h
>+++ b/include/uapi/linux/devlink.h
>@@ -141,6 +141,9 @@ enum devlink_command {
>
> DEVLINK_CMD_NOTIFY_FILTER_SET,
>
>+ DEVLINK_CMD_PORT_RESOURCE_GET, /* can dump */
>+ DEVLINK_CMD_PORT_RESOURCE_SET,
>+
> /* add new commands above here */
> __DEVLINK_CMD_MAX,
> DEVLINK_CMD_MAX = __DEVLINK_CMD_MAX - 1
>diff --git a/net/devlink/netlink.c b/net/devlink/netlink.c
>index 593605c1b1ef..c78c31779622 100644
>--- a/net/devlink/netlink.c
>+++ b/net/devlink/netlink.c
>@@ -367,7 +367,7 @@ struct genl_family devlink_nl_family __ro_after_init = {
> .module = THIS_MODULE,
> .split_ops = devlink_nl_ops,
> .n_split_ops = ARRAY_SIZE(devlink_nl_ops),
>- .resv_start_op = DEVLINK_CMD_SELFTESTS_RUN + 1,
>+ .resv_start_op = DEVLINK_CMD_PORT_RESOURCE_GET + 1,
> .mcgrps = devlink_nl_mcgrps,
> .n_mcgrps = ARRAY_SIZE(devlink_nl_mcgrps),
> .sock_priv_size = sizeof(struct devlink_nl_sock_priv),
>diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
>index f4c61c2b4f22..692d7862183a 100644
>--- a/net/devlink/netlink_gen.c
>+++ b/net/devlink/netlink_gen.c
>@@ -604,8 +604,21 @@ static const struct nla_policy
>devlink_notify_filter_set_nl_policy[DEVLINK_ATTR_
> [DEVLINK_ATTR_PORT_INDEX] = { .type = NLA_U32, },
> };
>
>+/* DEVLINK_CMD_PORT_RESOURCE_GET - do */
>+static const struct nla_policy
>devlink_port_resource_get_do_nl_policy[DEVLINK_ATTR_PORT_INDEX + 1] = {
>+ [DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
>+ [DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
>+ [DEVLINK_ATTR_PORT_INDEX] = { .type = NLA_U32, },
>+};
>+
>+/* DEVLINK_CMD_PORT_RESOURCE_GET - dump */
>+static const struct nla_policy
>devlink_port_resource_get_dump_nl_policy[DEVLINK_ATTR_DEV_NAME + 1] = {
>+ [DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
>+ [DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
>+};
>+
> /* Ops table for devlink */
>-const struct genl_split_ops devlink_nl_ops[74] = {
>+const struct genl_split_ops devlink_nl_ops[76] = {
> {
> .cmd = DEVLINK_CMD_GET,
> .validate = GENL_DONT_VALIDATE_STRICT,
>@@ -1284,4 +1297,21 @@ const struct genl_split_ops devlink_nl_ops[74] = {
> .maxattr = DEVLINK_ATTR_PORT_INDEX,
> .flags = GENL_CMD_CAP_DO,
> },
>+ {
>+ .cmd = DEVLINK_CMD_PORT_RESOURCE_GET,
>+ .validate = GENL_DONT_VALIDATE_STRICT,
>+ .pre_doit = devlink_nl_pre_doit_port,
>+ .doit = devlink_nl_port_resource_get_doit,
>+ .post_doit = devlink_nl_post_doit,
>+ .policy = devlink_port_resource_get_do_nl_policy,
>+ .maxattr = DEVLINK_ATTR_PORT_INDEX,
>+ .flags = GENL_CMD_CAP_DO,
>+ },
>+ {
>+ .cmd = DEVLINK_CMD_PORT_RESOURCE_GET,
>+ .dumpit = devlink_nl_port_resource_get_dumpit,
>+ .policy = devlink_port_resource_get_dump_nl_policy,
>+ .maxattr = DEVLINK_ATTR_DEV_NAME,
>+ .flags = GENL_CMD_CAP_DUMP,
>+ },
> };
>diff --git a/net/devlink/netlink_gen.h b/net/devlink/netlink_gen.h
>index 2817d53a0eba..204a665d2fd2 100644
>--- a/net/devlink/netlink_gen.h
>+++ b/net/devlink/netlink_gen.h
>@@ -18,7 +18,7 @@ extern const struct nla_policy
>devlink_dl_rate_tc_bws_nl_policy[DEVLINK_RATE_TC_
> extern const struct nla_policy
> devlink_dl_selftest_id_nl_policy[DEVLINK_ATTR_SELFTEST_ID_FLASH + 1];
>
> /* Ops table for devlink */
>-extern const struct genl_split_ops devlink_nl_ops[74];
>+extern const struct genl_split_ops devlink_nl_ops[76];
>
> int devlink_nl_pre_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
> struct genl_info *info);
>@@ -146,5 +146,9 @@ int devlink_nl_selftests_get_dumpit(struct sk_buff *skb,
> int devlink_nl_selftests_run_doit(struct sk_buff *skb, struct genl_info
> *info);
> int devlink_nl_notify_filter_set_doit(struct sk_buff *skb,
> struct genl_info *info);
>+int devlink_nl_port_resource_get_doit(struct sk_buff *skb,
>+ struct genl_info *info);
>+int devlink_nl_port_resource_get_dumpit(struct sk_buff *skb,
>+ struct netlink_callback *cb);
>
> #endif /* _LINUX_DEVLINK_GEN_H */
>diff --git a/net/devlink/resource.c b/net/devlink/resource.c
>index 1b06a1f408fa..42ad7c96a740 100644
>--- a/net/devlink/resource.c
>+++ b/net/devlink/resource.c
>@@ -227,6 +227,7 @@ static int devlink_resource_fill(struct genl_info *info,
> struct list_head *resource_list,
> enum devlink_command cmd, int flags)
> {
>+ struct devlink_port *devlink_port = info->user_ptr[1];
> struct devlink *devlink = info->user_ptr[0];
> struct devlink_resource *resource;
> struct nlattr *resources_attr;
>@@ -257,6 +258,10 @@ static int devlink_resource_fill(struct genl_info *info,
> if (devlink_nl_put_handle(skb, devlink))
> goto nla_put_failure;
>
>+ if (devlink_port && nla_put_u32(skb, DEVLINK_ATTR_PORT_INDEX,
>+ devlink_port->index))
>+ goto nla_put_failure;
>+
> resources_attr = nla_nest_start_noflag(skb,
> DEVLINK_ATTR_RESOURCE_LIST);
> if (!resources_attr)
>@@ -576,3 +581,99 @@ void devl_port_resources_unregister(struct devlink_port
>*devlink_port)
> &devlink_port->resource_list);
> }
> EXPORT_SYMBOL_GPL(devl_port_resources_unregister);
>+
>+static int devlink_nl_port_resource_fill(struct sk_buff *msg,
>+ struct devlink_port *devlink_port,
>+ enum devlink_command cmd,
>+ u32 portid, u32 seq, int flags)
>+{
>+ struct devlink *devlink = devlink_port->devlink;
>+ struct devlink_resource *resource;
>+ struct nlattr *resources_attr;
>+ void *hdr;
>+
>+ if (list_empty(&devlink_port->resource_list))
>+ return 0;
>+
>+ hdr = genlmsg_put(msg, portid, seq, &devlink_nl_family, flags, cmd);
>+ if (!hdr)
>+ return -EMSGSIZE;
>+
>+ if (devlink_nl_put_handle(msg, devlink))
>+ goto nla_put_failure;
>+ if (nla_put_u32(msg, DEVLINK_ATTR_PORT_INDEX, devlink_port->index))
>+ goto nla_put_failure;
>+
>+ resources_attr = nla_nest_start_noflag(msg, DEVLINK_ATTR_RESOURCE_LIST);
>+ if (!resources_attr)
>+ goto nla_put_failure;
>+
>+ list_for_each_entry(resource, &devlink_port->resource_list, list) {
>+ if (devlink_resource_put(devlink, msg, resource)) {
>+ nla_nest_cancel(msg, resources_attr);
>+ goto nla_put_failure;
>+ }
>+ }
>+ nla_nest_end(msg, resources_attr);
>+ genlmsg_end(msg, hdr);
>+ return 0;
>+
>+nla_put_failure:
>+ genlmsg_cancel(msg, hdr);
>+ return -EMSGSIZE;
Why you don't unify this function with existing devlink_resource_fill()?
Unnecessary code duplication, plus devlink_resource_fill() already know
how to handle multipart message.
This is related to my request to implement dump for devlink dev
resources. I would like to see the code unification for dump ops as
well.
Thanks!
>+}
>+
>+int devlink_nl_port_resource_get_doit(struct sk_buff *skb,
>+ struct genl_info *info)
>+{
>+ struct devlink_port *devlink_port = info->user_ptr[1];
>+ struct sk_buff *msg;
>+ int err;
>+
>+ msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
>+ if (!msg)
>+ return -ENOMEM;
>+
>+ err = devlink_nl_port_resource_fill(msg, devlink_port,
>+ DEVLINK_CMD_PORT_RESOURCE_GET,
>+ info->snd_portid, info->snd_seq, 0);
>+ if (err) {
>+ nlmsg_free(msg);
>+ return err;
>+ }
>+
>+ return genlmsg_reply(msg, info);
>+}
>+
>+static int
>+devlink_nl_port_resource_get_dump_one(struct sk_buff *msg,
>+ struct devlink *devlink,
>+ struct netlink_callback *cb, int flags)
>+{
>+ enum devlink_command cmd = DEVLINK_CMD_PORT_RESOURCE_GET;
>+ struct devlink_nl_dump_state *state = devlink_dump_state(cb);
>+ struct devlink_port *devlink_port;
>+ unsigned long port_index;
>+ int err;
>+
>+ xa_for_each_start(&devlink->ports, port_index, devlink_port,
>+ state->idx) {
>+ err = devlink_nl_port_resource_fill(msg, devlink_port,
>+ cmd,
>+ NETLINK_CB(cb->skb).portid,
>+ cb->nlh->nlmsg_seq, flags);
>+ if (err) {
>+ state->idx = port_index;
>+ return err;
>+ }
>+ }
>+
>+ return 0;
>+}
>+
>+int devlink_nl_port_resource_get_dumpit(struct sk_buff *skb,
>+ struct netlink_callback *cb)
>+{
>+ return devlink_nl_dumpit(skb, cb,
>+ devlink_nl_port_resource_get_dump_one);
>+}
>--
>2.44.0
>
