Documentation/netlink/specs/devlink.yaml | 4 ++ include/net/devlink.h | 8 ++++ include/uapi/linux/devlink.h | 1 + net/devlink/netlink_gen.c | 2 + net/devlink/param.c | 54 +++++++++++++++++++----- 5 files changed, 59 insertions(+), 10 deletions(-)
From: Saeed Mahameed <saeedm@nvidia.com>
Devlink param value attribute is not defined since devlink is handling
the value validating and parsing internally, this allows us to implement
multi attribute values without breaking any policies.
Devlink param multi-attribute values are considered to be dynamically
sized arrays of u32 values, by introducing a new devlink param type
DEVLINK_PARAM_TYPE_U32_ARRAY, driver and user space can set a variable
count of u32 values into the DEVLINK_ATTR_PARAM_VALUE_DATA attribute.
Implement get/set parsing and add to the internal value structure passed
to drivers.
This is useful for devices that need to configure a list of values for
a specific configuration.
example:
$ devlink dev param show pci/... name multi-value-param
name multi-value-param type driver-specific
values:
cmode permanent value: 0,1,2,3,4,5,6,7
$ devlink dev param set pci/... name multi-value-param \
value 4,5,6,7,0,1,2,3 cmode permanent
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
---
v1 -> v2: Fixed build errors and AI warnings.
---
Documentation/netlink/specs/devlink.yaml | 4 ++
include/net/devlink.h | 8 ++++
include/uapi/linux/devlink.h | 1 +
net/devlink/netlink_gen.c | 2 +
net/devlink/param.c | 54 +++++++++++++++++++-----
5 files changed, 59 insertions(+), 10 deletions(-)
diff --git a/Documentation/netlink/specs/devlink.yaml b/Documentation/netlink/specs/devlink.yaml
index 837112da6738..e8a8287c4f19 100644
--- a/Documentation/netlink/specs/devlink.yaml
+++ b/Documentation/netlink/specs/devlink.yaml
@@ -226,6 +226,10 @@ definitions:
value: 10
-
name: binary
+ -
+ name: u32-array
+ value: 129
+
-
name: rate-tc-index-max
type: const
diff --git a/include/net/devlink.h b/include/net/devlink.h
index cb839e0435a1..0a496715da99 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -432,6 +432,13 @@ enum devlink_param_type {
DEVLINK_PARAM_TYPE_U64 = DEVLINK_VAR_ATTR_TYPE_U64,
DEVLINK_PARAM_TYPE_STRING = DEVLINK_VAR_ATTR_TYPE_STRING,
DEVLINK_PARAM_TYPE_BOOL = DEVLINK_VAR_ATTR_TYPE_FLAG,
+ DEVLINK_PARAM_TYPE_U32_ARRAY = DEVLINK_VAR_ATTR_TYPE_U32_ARRAY,
+};
+
+#define __DEVLINK_PARAM_MAX_ARRAY_SIZE 32
+struct devlink_param_u32_array {
+ u32 size;
+ u32 val[__DEVLINK_PARAM_MAX_ARRAY_SIZE];
};
union devlink_param_value {
@@ -441,6 +448,7 @@ union devlink_param_value {
u64 vu64;
char vstr[__DEVLINK_PARAM_MAX_STRING_VALUE];
bool vbool;
+ struct devlink_param_u32_array u32arr;
};
struct devlink_param_gset_ctx {
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index e7d6b6d13470..768d0d88710f 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -404,6 +404,7 @@ enum devlink_var_attr_type {
DEVLINK_VAR_ATTR_TYPE_BINARY,
__DEVLINK_VAR_ATTR_TYPE_CUSTOM_BASE = 0x80,
/* Any possible custom types, unrelated to NLA_* values go below */
+ DEVLINK_VAR_ATTR_TYPE_U32_ARRAY,
};
enum devlink_attr {
diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
index f4c61c2b4f22..e5a80eb467b8 100644
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@@ -32,6 +32,8 @@ devlink_attr_param_type_validate(const struct nlattr *attr,
case DEVLINK_VAR_ATTR_TYPE_NUL_STRING:
fallthrough;
case DEVLINK_VAR_ATTR_TYPE_BINARY:
+ fallthrough;
+ case DEVLINK_VAR_ATTR_TYPE_U32_ARRAY:
return 0;
}
NL_SET_ERR_MSG_ATTR(extack, attr, "invalid enum value");
diff --git a/net/devlink/param.c b/net/devlink/param.c
index e0ea93eded43..4d0e5fa223db 100644
--- a/net/devlink/param.c
+++ b/net/devlink/param.c
@@ -252,6 +252,14 @@ devlink_nl_param_value_put(struct sk_buff *msg, enum devlink_param_type type,
return -EMSGSIZE;
}
break;
+ case DEVLINK_PARAM_TYPE_U32_ARRAY:
+ if (val.u32arr.size > __DEVLINK_PARAM_MAX_ARRAY_SIZE)
+ return -EMSGSIZE;
+
+ for (int i = 0; i < val.u32arr.size; i++)
+ if (nla_put_u32(msg, nla_type, val.u32arr.val[i]))
+ return -EMSGSIZE;
+ break;
}
return 0;
}
@@ -304,8 +312,10 @@ static int devlink_nl_param_fill(struct sk_buff *msg, struct devlink *devlink,
u32 portid, u32 seq, int flags,
struct netlink_ext_ack *extack)
{
- union devlink_param_value default_value[DEVLINK_PARAM_CMODE_MAX + 1];
- union devlink_param_value param_value[DEVLINK_PARAM_CMODE_MAX + 1];
+ union devlink_param_value __free(kfree)
+ (*default_value)[DEVLINK_PARAM_CMODE_MAX + 1] = { NULL };
+ union devlink_param_value __free(kfree)
+ (*param_value)[DEVLINK_PARAM_CMODE_MAX + 1] = { NULL };
bool default_value_set[DEVLINK_PARAM_CMODE_MAX + 1] = {};
bool param_value_set[DEVLINK_PARAM_CMODE_MAX + 1] = {};
const struct devlink_param *param = param_item->param;
@@ -316,20 +326,28 @@ static int devlink_nl_param_fill(struct sk_buff *msg, struct devlink *devlink,
int err;
int i;
+ default_value = kmalloc(sizeof(*default_value), GFP_KERNEL);
+ if (!default_value)
+ return -ENOMEM;
+
+ param_value = kmalloc(sizeof(*param_value), GFP_KERNEL);
+ if (!param_value)
+ return -ENOMEM;
+
/* Get value from driver part to driverinit configuration mode */
for (i = 0; i <= DEVLINK_PARAM_CMODE_MAX; i++) {
if (!devlink_param_cmode_is_supported(param, i))
continue;
if (i == DEVLINK_PARAM_CMODE_DRIVERINIT) {
if (param_item->driverinit_value_new_valid)
- param_value[i] = param_item->driverinit_value_new;
+ (*param_value)[i] = param_item->driverinit_value_new;
else if (param_item->driverinit_value_valid)
- param_value[i] = param_item->driverinit_value;
+ (*param_value)[i] = param_item->driverinit_value;
else
return -EOPNOTSUPP;
if (param_item->driverinit_value_valid) {
- default_value[i] = param_item->driverinit_default;
+ (*default_value)[i] = param_item->driverinit_default;
default_value_set[i] = true;
}
} else {
@@ -337,12 +355,12 @@ static int devlink_nl_param_fill(struct sk_buff *msg, struct devlink *devlink,
err = devlink_param_get(devlink, param, &ctx, extack);
if (err)
return err;
- param_value[i] = ctx.val;
+ (*param_value)[i] = ctx.val;
err = devlink_param_get_default(devlink, param, &ctx,
extack);
if (!err) {
- default_value[i] = ctx.val;
+ (*default_value)[i] = ctx.val;
default_value_set[i] = true;
} else if (err != -EOPNOTSUPP) {
return err;
@@ -383,8 +401,8 @@ static int devlink_nl_param_fill(struct sk_buff *msg, struct devlink *devlink,
if (!param_value_set[i])
continue;
err = devlink_nl_param_value_fill_one(msg, param->type,
- i, param_value[i],
- default_value[i],
+ i, (*param_value)[i],
+ (*default_value)[i],
default_value_set[i]);
if (err)
goto values_list_nest_cancel;
@@ -507,7 +525,7 @@ devlink_param_value_get_from_info(const struct devlink_param *param,
union devlink_param_value *value)
{
struct nlattr *param_data;
- int len;
+ int len, cnt, rem;
param_data = info->attrs[DEVLINK_ATTR_PARAM_VALUE_DATA];
@@ -547,6 +565,22 @@ devlink_param_value_get_from_info(const struct devlink_param *param,
return -EINVAL;
value->vbool = nla_get_flag(param_data);
break;
+
+ case DEVLINK_PARAM_TYPE_U32_ARRAY:
+ cnt = 0;
+ nla_for_each_attr_type(param_data,
+ DEVLINK_ATTR_PARAM_VALUE_DATA,
+ genlmsg_data(info->genlhdr),
+ genlmsg_len(info->genlhdr), rem) {
+ if (cnt >= __DEVLINK_PARAM_MAX_ARRAY_SIZE)
+ return -EMSGSIZE;
+
+ value->u32arr.val[cnt] = nla_get_u32(param_data);
+ cnt++;
+ }
+
+ value->u32arr.size = cnt;
+ break;
}
return 0;
}
--
2.43.0On Mon, 26 Jan 2026 08:09:44 +0530 Ratheesh Kannoth wrote: > Devlink param value attribute is not defined since devlink is handling > the value validating and parsing internally, this allows us to implement > multi attribute values without breaking any policies. > > Devlink param multi-attribute values are considered to be dynamically > sized arrays of u32 values, by introducing a new devlink param type > DEVLINK_PARAM_TYPE_U32_ARRAY, driver and user space can set a variable > count of u32 values into the DEVLINK_ATTR_PARAM_VALUE_DATA attribute. > > Implement get/set parsing and add to the internal value structure passed > to drivers. > > This is useful for devices that need to configure a list of values for > a specific configuration. Could you respin this as a series with the first driver implementing a param of this type? We can't merge an API without a user. -- pw-bot: cr
Tue, Jan 27, 2026 at 02:18:59AM +0100, kuba@kernel.org wrote: >On Mon, 26 Jan 2026 08:09:44 +0530 Ratheesh Kannoth wrote: >> Devlink param value attribute is not defined since devlink is handling >> the value validating and parsing internally, this allows us to implement >> multi attribute values without breaking any policies. >> >> Devlink param multi-attribute values are considered to be dynamically >> sized arrays of u32 values, by introducing a new devlink param type >> DEVLINK_PARAM_TYPE_U32_ARRAY, driver and user space can set a variable >> count of u32 values into the DEVLINK_ATTR_PARAM_VALUE_DATA attribute. >> >> Implement get/set parsing and add to the internal value structure passed >> to drivers. >> >> This is useful for devices that need to configure a list of values for >> a specific configuration. > >Could you respin this as a series with the first driver implementing >a param of this type? We can't merge an API without a user. I may be missed it, are you okay with cleanup helpers now (__free(kfree) used here), or not yet? :)
On Tue, 27 Jan 2026 10:51:10 +0100 Jiri Pirko wrote: > Tue, Jan 27, 2026 at 02:18:59AM +0100, kuba@kernel.org wrote: > >On Mon, 26 Jan 2026 08:09:44 +0530 Ratheesh Kannoth wrote: > >> Devlink param value attribute is not defined since devlink is handling > >> the value validating and parsing internally, this allows us to implement > >> multi attribute values without breaking any policies. > >> > >> Devlink param multi-attribute values are considered to be dynamically > >> sized arrays of u32 values, by introducing a new devlink param type > >> DEVLINK_PARAM_TYPE_U32_ARRAY, driver and user space can set a variable > >> count of u32 values into the DEVLINK_ATTR_PARAM_VALUE_DATA attribute. > >> > >> Implement get/set parsing and add to the internal value structure passed > >> to drivers. > >> > >> This is useful for devices that need to configure a list of values for > >> a specific configuration. > > > >Could you respin this as a series with the first driver implementing > >a param of this type? We can't merge an API without a user. > > I may be missed it, are you okay with cleanup helpers now (__free(kfree) > used here), or not yet? :) Of course not, I haven't looked at the patch at all.
On 2026-01-27 at 23:34:29, Jakub Kicinski (kuba@kernel.org) wrote: > On Tue, 27 Jan 2026 10:51:10 +0100 Jiri Pirko wrote: > > Tue, Jan 27, 2026 at 02:18:59AM +0100, kuba@kernel.org wrote: > > >On Mon, 26 Jan 2026 08:09:44 +0530 Ratheesh Kannoth wrote: > > >> Devlink param value attribute is not defined since devlink is handling > > >> the value validating and parsing internally, this allows us to implement > > >> multi attribute values without breaking any policies. > > >> > > >> Devlink param multi-attribute values are considered to be dynamically > > >> sized arrays of u32 values, by introducing a new devlink param type > > >> DEVLINK_PARAM_TYPE_U32_ARRAY, driver and user space can set a variable > > >> count of u32 values into the DEVLINK_ATTR_PARAM_VALUE_DATA attribute. > > >> > > >> Implement get/set parsing and add to the internal value structure passed > > >> to drivers. > > >> > > >> This is useful for devices that need to configure a list of values for > > >> a specific configuration. > > > > > >Could you respin this as a series with the first driver implementing > > >a param of this type? We can't merge an API without a user. > > > > I may be missed it, are you okay with cleanup helpers now (__free(kfree) > > used here), or not yet? :) > > Of course not, Will remove it. Thanks, >I haven't looked at the patch at all.
On 2026-01-27 at 06:48:59, Jakub Kicinski (kuba@kernel.org) wrote: > On Mon, 26 Jan 2026 08:09:44 +0530 Ratheesh Kannoth wrote: > > Devlink param value attribute is not defined since devlink is handling > > the value validating and parsing internally, this allows us to implement > > multi attribute values without breaking any policies. > > > > Devlink param multi-attribute values are considered to be dynamically > > sized arrays of u32 values, by introducing a new devlink param type > > DEVLINK_PARAM_TYPE_U32_ARRAY, driver and user space can set a variable > > count of u32 values into the DEVLINK_ATTR_PARAM_VALUE_DATA attribute. > > > > Implement get/set parsing and add to the internal value structure passed > > to drivers. > > > > This is useful for devices that need to configure a list of values for > > a specific configuration. > > Could you respin this as a series with the first driver implementing > a param of this type? We can't merge an API without a user. ACK. will make it part of https://patchwork.kernel.org/project/netdevbpf/list/?series=1047093 as APIs needed by devlink are in this patch. > -- > pw-bot: cr
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