* [PATCH iproute2-next v2 1/2] devlink: Pull the value printing logic out of pr_out_param_value()
2026-02-06 21:11 [PATCH iproute2-next v2 0/2] devlink: support default flag attr for param-get and param-set commands Daniel Zahka
@ 2026-02-06 21:11 ` Daniel Zahka
2026-02-06 21:11 ` [PATCH iproute2-next v2 2/2] devlink: support displaying and resetting to default params Daniel Zahka
2026-02-19 17:00 ` [PATCH iproute2-next v2 0/2] devlink: support default flag attr for param-get and param-set commands patchwork-bot+netdevbpf
2 siblings, 0 replies; 4+ messages in thread
From: Daniel Zahka @ 2026-02-06 21:11 UTC (permalink / raw)
To: Jiri Pirko, David S. Miller, Jakub Kicinski, Paolo Abeni,
Simon Horman, Donald Hunter, David Ahern
Cc: netdev, linux-kernel, Daniel Zahka
Split the type demux and value print out of pr_out_param_value() into
a new function pr_out_param_value_print(). This new function can be
re-used for printing additional kinds of values e.g., a default value
reported by the kernel.
Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
---
devlink/devlink.c | 79 ++++++++++++++++++++++++++++++++-----------------------
1 file changed, 46 insertions(+), 33 deletions(-)
diff --git a/devlink/devlink.c b/devlink/devlink.c
index 0b3bf197..81739291 100644
--- a/devlink/devlink.c
+++ b/devlink/devlink.c
@@ -3502,32 +3502,14 @@ static const struct param_val_conv param_val_conv[] = {
#define PARAM_VAL_CONV_LEN ARRAY_SIZE(param_val_conv)
-static void pr_out_param_value(struct dl *dl, const char *nla_name,
- int nla_type, struct nlattr *nl)
+static int pr_out_param_value_print(const char *nla_name, int nla_type,
+ struct nlattr *val_attr, bool conv_exists,
+ const char *label)
{
- struct nlattr *nla_value[DEVLINK_ATTR_MAX + 1] = {};
- struct nlattr *val_attr;
const char *vstr;
- bool conv_exists;
int err;
- err = mnl_attr_parse_nested(nl, attr_cb, nla_value);
- if (err != MNL_CB_OK)
- return;
-
- if (!nla_value[DEVLINK_ATTR_PARAM_VALUE_CMODE] ||
- (nla_type != MNL_TYPE_FLAG &&
- !nla_value[DEVLINK_ATTR_PARAM_VALUE_DATA]))
- return;
-
- check_indent_newline(dl);
- print_string(PRINT_ANY, "cmode", "cmode %s",
- param_cmode_name(mnl_attr_get_u8(nla_value[DEVLINK_ATTR_PARAM_VALUE_CMODE])));
-
- val_attr = nla_value[DEVLINK_ATTR_PARAM_VALUE_DATA];
-
- conv_exists = param_val_conv_exists(param_val_conv, PARAM_VAL_CONV_LEN,
- nla_name);
+ print_string(PRINT_FP, NULL, " %s ", label);
switch (nla_type) {
case MNL_TYPE_U8:
@@ -3538,10 +3520,10 @@ static void pr_out_param_value(struct dl *dl, const char *nla_name,
mnl_attr_get_u8(val_attr),
&vstr);
if (err)
- return;
- print_string(PRINT_ANY, "value", " value %s", vstr);
+ return err;
+ print_string(PRINT_ANY, label, "%s", vstr);
} else {
- print_uint(PRINT_ANY, "value", " value %u",
+ print_uint(PRINT_ANY, label, "%u",
mnl_attr_get_u8(val_attr));
}
break;
@@ -3553,10 +3535,10 @@ static void pr_out_param_value(struct dl *dl, const char *nla_name,
mnl_attr_get_u16(val_attr),
&vstr);
if (err)
- return;
- print_string(PRINT_ANY, "value", " value %s", vstr);
+ return err;
+ print_string(PRINT_ANY, label, "%s", vstr);
} else {
- print_uint(PRINT_ANY, "value", " value %u",
+ print_uint(PRINT_ANY, label, "%u",
mnl_attr_get_u16(val_attr));
}
break;
@@ -3568,21 +3550,52 @@ static void pr_out_param_value(struct dl *dl, const char *nla_name,
mnl_attr_get_u32(val_attr),
&vstr);
if (err)
- return;
- print_string(PRINT_ANY, "value", " value %s", vstr);
+ return err;
+ print_string(PRINT_ANY, label, "%s", vstr);
} else {
- print_uint(PRINT_ANY, "value", " value %u",
+ print_uint(PRINT_ANY, label, "%u",
mnl_attr_get_u32(val_attr));
}
break;
case MNL_TYPE_STRING:
- print_string(PRINT_ANY, "value", " value %s",
+ print_string(PRINT_ANY, label, "%s",
mnl_attr_get_str(val_attr));
break;
case MNL_TYPE_FLAG:
- print_bool(PRINT_ANY, "value", " value %s", val_attr);
+ print_bool(PRINT_ANY, label, "%s", val_attr);
break;
}
+
+ return 0;
+}
+
+static void pr_out_param_value(struct dl *dl, const char *nla_name,
+ int nla_type, struct nlattr *nl)
+{
+ struct nlattr *nla_value[DEVLINK_ATTR_MAX + 1] = {};
+ struct nlattr *val_attr;
+ bool conv_exists;
+ int err;
+
+ err = mnl_attr_parse_nested(nl, attr_cb, nla_value);
+ if (err != MNL_CB_OK)
+ return;
+
+ if (!nla_value[DEVLINK_ATTR_PARAM_VALUE_CMODE] ||
+ (nla_type != MNL_TYPE_FLAG &&
+ !nla_value[DEVLINK_ATTR_PARAM_VALUE_DATA]))
+ return;
+
+ check_indent_newline(dl);
+ print_string(PRINT_ANY, "cmode", "cmode %s",
+ param_cmode_name(mnl_attr_get_u8(nla_value[DEVLINK_ATTR_PARAM_VALUE_CMODE])));
+
+ val_attr = nla_value[DEVLINK_ATTR_PARAM_VALUE_DATA];
+
+ conv_exists = param_val_conv_exists(param_val_conv, PARAM_VAL_CONV_LEN,
+ nla_name);
+
+ pr_out_param_value_print(nla_name, nla_type, val_attr, conv_exists, "value");
}
static void pr_out_param(struct dl *dl, struct nlattr **tb, bool array,
--
2.47.3
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH iproute2-next v2 2/2] devlink: support displaying and resetting to default params
2026-02-06 21:11 [PATCH iproute2-next v2 0/2] devlink: support default flag attr for param-get and param-set commands Daniel Zahka
2026-02-06 21:11 ` [PATCH iproute2-next v2 1/2] devlink: Pull the value printing logic out of pr_out_param_value() Daniel Zahka
@ 2026-02-06 21:11 ` Daniel Zahka
2026-02-19 17:00 ` [PATCH iproute2-next v2 0/2] devlink: support default flag attr for param-get and param-set commands patchwork-bot+netdevbpf
2 siblings, 0 replies; 4+ messages in thread
From: Daniel Zahka @ 2026-02-06 21:11 UTC (permalink / raw)
To: Jiri Pirko, David S. Miller, Jakub Kicinski, Paolo Abeni,
Simon Horman, Donald Hunter, David Ahern
Cc: netdev, linux-kernel, Daniel Zahka
Add devlink cli support for default param values.
For param-get, any default values provided by the kernel will be
displayed next to the current value. For param-set,
DEVLINK_ATTR_PARAM_RESET_DEFAULT can be included in the request to
request that the parameter be reset to its default value.
Default values of type bool are encoded with a u8 by the kernel to
distinguish "false" from "not present".
Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
---
devlink/devlink.c | 54 ++++++++++++++++++++++++++++++++++++++++++++------
man/man8/devlink-dev.8 | 22 ++++++++++++++++++--
2 files changed, 68 insertions(+), 8 deletions(-)
diff --git a/devlink/devlink.c b/devlink/devlink.c
index 81739291..39b0fac0 100644
--- a/devlink/devlink.c
+++ b/devlink/devlink.c
@@ -313,6 +313,7 @@ static int ifname_map_update(struct ifname_map *ifname_map, const char *ifname)
#define DL_OPT_PORT_FN_MAX_IO_EQS BIT(58)
#define DL_OPT_PORT_FN_RATE_TC_BWS BIT(59)
#define DL_OPT_HEALTH_REPORTER_BURST_PERIOD BIT(60)
+#define DL_OPT_PARAM_SET_DEFAULT BIT(61)
struct dl_opts {
uint64_t present; /* flags of present items */
@@ -2011,6 +2012,10 @@ static int dl_argv_parse(struct dl *dl, uint64_t o_required,
if (err)
return err;
o_found |= DL_OPT_PARAM_CMODE;
+ } else if (dl_argv_match(dl, "default") &&
+ (o_all & DL_OPT_PARAM_SET_DEFAULT)) {
+ dl_arg_inc(dl);
+ o_found |= DL_OPT_PARAM_SET_DEFAULT;
} else if (dl_argv_match(dl, "snapshot") &&
(o_all & DL_OPT_REGION_SNAPSHOT_ID)) {
dl_arg_inc(dl);
@@ -2672,6 +2677,8 @@ static void dl_opts_put(struct nlmsghdr *nlh, struct dl *dl)
if (opts->present & DL_OPT_PARAM_CMODE)
mnl_attr_put_u8(nlh, DEVLINK_ATTR_PARAM_VALUE_CMODE,
opts->cmode);
+ if (opts->present & DL_OPT_PARAM_SET_DEFAULT)
+ mnl_attr_put(nlh, DEVLINK_ATTR_PARAM_RESET_DEFAULT, 0, NULL);
if (opts->present & DL_OPT_REGION_SNAPSHOT_ID)
mnl_attr_put_u32(nlh, DEVLINK_ATTR_REGION_SNAPSHOT_ID,
opts->region_snapshot_id);
@@ -2839,7 +2846,7 @@ static void cmd_dev_help(void)
pr_err(" [ inline-mode { none | link | network | transport } ]\n");
pr_err(" [ encap-mode { none | basic } ]\n");
pr_err(" devlink dev eswitch show DEV\n");
- pr_err(" devlink dev param set DEV name PARAMETER value VALUE cmode { permanent | driverinit | runtime }\n");
+ pr_err(" devlink dev param set DEV name PARAMETER [ value VALUE | default ] cmode { permanent | driverinit | runtime }\n");
pr_err(" devlink dev param show [DEV name PARAMETER]\n");
pr_err(" devlink dev reload DEV [ netns { PID | NAME | ID } ]\n");
pr_err(" [ action { driver_reinit | fw_activate } ] [ limit no_reset ]\n");
@@ -3504,7 +3511,7 @@ static const struct param_val_conv param_val_conv[] = {
static int pr_out_param_value_print(const char *nla_name, int nla_type,
struct nlattr *val_attr, bool conv_exists,
- const char *label)
+ const char *label, bool flag_as_u8)
{
const char *vstr;
int err;
@@ -3562,7 +3569,11 @@ static int pr_out_param_value_print(const char *nla_name, int nla_type,
mnl_attr_get_str(val_attr));
break;
case MNL_TYPE_FLAG:
- print_bool(PRINT_ANY, label, "%s", val_attr);
+ if (flag_as_u8)
+ print_bool(PRINT_ANY, label, "%s",
+ mnl_attr_get_u8(val_attr));
+ else
+ print_bool(PRINT_ANY, label, "%s", val_attr);
break;
}
@@ -3595,7 +3606,18 @@ static void pr_out_param_value(struct dl *dl, const char *nla_name,
conv_exists = param_val_conv_exists(param_val_conv, PARAM_VAL_CONV_LEN,
nla_name);
- pr_out_param_value_print(nla_name, nla_type, val_attr, conv_exists, "value");
+ err = pr_out_param_value_print(nla_name, nla_type, val_attr,
+ conv_exists, "value", false);
+ if (err)
+ return;
+
+ val_attr = nla_value[DEVLINK_ATTR_PARAM_VALUE_DEFAULT];
+ if (val_attr) {
+ err = pr_out_param_value_print(nla_name, nla_type, val_attr,
+ conv_exists, "default", true);
+ if (err)
+ return;
+ }
}
static void pr_out_param(struct dl *dl, struct nlattr **tb, bool array,
@@ -3764,11 +3786,23 @@ static int cmd_dev_param_set(struct dl *dl)
err = dl_argv_parse(dl, DL_OPT_HANDLE |
DL_OPT_PARAM_NAME |
- DL_OPT_PARAM_VALUE |
- DL_OPT_PARAM_CMODE, 0);
+ DL_OPT_PARAM_CMODE,
+ DL_OPT_PARAM_VALUE | DL_OPT_PARAM_SET_DEFAULT);
if (err)
return err;
+ if ((dl->opts.present & DL_OPT_PARAM_VALUE) &&
+ (dl->opts.present & DL_OPT_PARAM_SET_DEFAULT)) {
+ pr_err("Cannot specify both value and default\n");
+ return -EINVAL;
+ }
+
+ if (!(dl->opts.present & DL_OPT_PARAM_VALUE) &&
+ !(dl->opts.present & DL_OPT_PARAM_SET_DEFAULT)) {
+ pr_err("Either value or default must be specified\n");
+ return -EINVAL;
+ }
+
/* Get value type */
nlh = mnlu_gen_socket_cmd_prepare(&dl->nlg, DEVLINK_CMD_PARAM_GET,
NLM_F_REQUEST | NLM_F_ACK);
@@ -3783,6 +3817,14 @@ static int cmd_dev_param_set(struct dl *dl)
return -ENOTSUP;
}
+ if (dl->opts.present & DL_OPT_PARAM_SET_DEFAULT) {
+ nlh = mnlu_gen_socket_cmd_prepare(&dl->nlg, DEVLINK_CMD_PARAM_SET,
+ NLM_F_REQUEST | NLM_F_ACK);
+ dl_opts_put(nlh, dl);
+ mnl_attr_put_u8(nlh, DEVLINK_ATTR_PARAM_TYPE, ctx.nla_type);
+ return mnlu_gen_socket_sndrcv(&dl->nlg, nlh, NULL, NULL);
+ }
+
nlh = mnlu_gen_socket_cmd_prepare(&dl->nlg, DEVLINK_CMD_PARAM_SET,
NLM_F_REQUEST | NLM_F_ACK);
dl_opts_put(nlh, dl);
diff --git a/man/man8/devlink-dev.8 b/man/man8/devlink-dev.8
index d10b1f9a..ad65f6f8 100644
--- a/man/man8/devlink-dev.8
+++ b/man/man8/devlink-dev.8
@@ -45,8 +45,12 @@ devlink-dev \- devlink device configuration
.I DEV
.B name
.I PARAMETER
+[
.B value
.I VALUE
+|
+.B default
+]
.BR cmode " { " runtime " | " driverinit " | " permanent " } "
.ti -8
@@ -159,7 +163,13 @@ Specify parameter name to set.
.TP
.BI value " VALUE"
-New value to set.
+New value to set. Mutually exclusive with
+.BR default .
+
+.TP
+.B default
+Restore parameter to its default value. Mutually exclusive with
+.BR value .
.TP
.BR cmode " { " runtime " | " driverinit " | " permanent " } "
@@ -176,10 +186,13 @@ Configuration mode in which the new value is set.
.SS devlink dev param show - display devlink device supported configuration parameters attributes
+.TP
.B name
.I PARAMETER
Specify parameter name to show.
If this argument is omitted all parameters supported by devlink devices are listed.
+When the kernel provides a default value for a parameter, it will be automatically displayed
+in the output alongside the current value.
.SS devlink dev reload - perform hot reload of the driver.
@@ -309,7 +322,7 @@ Sets the eswitch mode of specified devlink device to switchdev.
.PP
devlink dev param show pci/0000:01:00.0 name max_macs
.RS 4
-Shows the parameter max_macs attributes.
+Shows the parameter max_macs attributes. If a default value exists, it will be displayed alongside the current value.
.RE
.PP
devlink dev param set pci/0000:01:00.0 name internal_error_reset value true cmode runtime
@@ -317,6 +330,11 @@ devlink dev param set pci/0000:01:00.0 name internal_error_reset value true cmod
Sets the parameter internal_error_reset of specified devlink device to true.
.RE
.PP
+devlink dev param set pci/0000:01:00.0 name internal_error_reset default cmode runtime
+.RS 4
+Restores the parameter internal_error_reset of specified devlink device to its default value.
+.RE
+.PP
devlink dev reload pci/0000:01:00.0
.RS 4
Performs hot reload of specified devlink device.
--
2.47.3
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH iproute2-next v2 0/2] devlink: support default flag attr for param-get and param-set commands
2026-02-06 21:11 [PATCH iproute2-next v2 0/2] devlink: support default flag attr for param-get and param-set commands Daniel Zahka
2026-02-06 21:11 ` [PATCH iproute2-next v2 1/2] devlink: Pull the value printing logic out of pr_out_param_value() Daniel Zahka
2026-02-06 21:11 ` [PATCH iproute2-next v2 2/2] devlink: support displaying and resetting to default params Daniel Zahka
@ 2026-02-19 17:00 ` patchwork-bot+netdevbpf
2 siblings, 0 replies; 4+ messages in thread
From: patchwork-bot+netdevbpf @ 2026-02-19 17:00 UTC (permalink / raw)
To: Daniel Zahka
Cc: jiri, davem, kuba, pabeni, horms, donald.hunter, dsahern, netdev,
linux-kernel
Hello:
This series was applied to iproute2/iproute2-next.git (main)
by David Ahern <dsahern@kernel.org>:
On Fri, 06 Feb 2026 13:11:28 -0800 you wrote:
> Add cli support for default param values introduced in the
> accompanying kernel series [1]. Here is some sample usage:
>
> [1]: https://lore.kernel.org/netdev/20251119025038.651131-1-daniel.zahka@gmail.com/
>
> # dump params with defaults
> ./devlink dev param show pci/0000:01:00.0
> pci/0000:01:00.0:
> name max_macs type generic
> values:
> cmode driverinit value 128 default 128
> ...
> name swp_l4_csum_mode type driver-specific
> values:
> cmode permanent value default default default
>
> [...]
Here is the summary with links:
- [iproute2-next,v2,1/2] devlink: Pull the value printing logic out of pr_out_param_value()
https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=bbe2c8b3229d
- [iproute2-next,v2,2/2] devlink: support displaying and resetting to default params
https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=446dd2c18952
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 4+ messages in thread