2020-08-30 15:30:21

by Moshe Shemesh

[permalink] [raw]
Subject: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

Add devlink reload action to allow the user to request a specific reload
action. The action parameter is optional, if not specified then devlink
driver re-init action is used (backward compatible).
Note that when required to do firmware activation some drivers may need
to reload the driver. On the other hand some drivers may need to reset
the firmware to reinitialize the driver entities. Therefore, the devlink
reload command returns the actions which were actually done.
However, in case fw_activate_no_reset action is selected, then no other
reload action is allowed.
Reload actions supported are:
driver_reinit: driver entities re-initialization, applying devlink-param
and devlink-resource values.
fw_activate: firmware activate.
fw_activate_no_reset: Activate new firmware image without any reset.
(also known as: firmware live patching).

command examples:
$devlink dev reload pci/0000:82:00.0 action driver_reinit
reload_actions_done:
driver_reinit

$devlink dev reload pci/0000:82:00.0 action fw_activate
reload_actions_done:
driver_reinit fw_activate

Signed-off-by: Moshe Shemesh <[email protected]>
---
v2 -> v3:
- Replace fw_live_patch action by fw_activate_no_reset
- Devlink reload returns the actions done over netlink reply
v1 -> v2:
- Instead of reload levels driver,fw_reset,fw_live_patch have reload
actions driver_reinit,fw_activate,fw_live_patch
- Remove driver default level, the action driver_reinit is the default
action for all drivers
---
drivers/net/ethernet/mellanox/mlx4/main.c | 14 ++-
.../net/ethernet/mellanox/mlx5/core/devlink.c | 15 ++-
drivers/net/ethernet/mellanox/mlxsw/core.c | 24 ++--
drivers/net/netdevsim/dev.c | 16 ++-
include/net/devlink.h | 7 +-
include/uapi/linux/devlink.h | 21 ++++
net/core/devlink.c | 112 +++++++++++++++++-
7 files changed, 182 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 258c7a96f269..3aeaa87556c8 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -3935,6 +3935,7 @@ static int mlx4_restart_one_up(struct pci_dev *pdev, bool reload,
struct devlink *devlink);

static int mlx4_devlink_reload_down(struct devlink *devlink, bool netns_change,
+ enum devlink_reload_action action,
struct netlink_ext_ack *extack)
{
struct mlx4_priv *priv = devlink_priv(devlink);
@@ -3951,8 +3952,8 @@ static int mlx4_devlink_reload_down(struct devlink *devlink, bool netns_change,
return 0;
}

-static int mlx4_devlink_reload_up(struct devlink *devlink,
- struct netlink_ext_ack *extack)
+static int mlx4_devlink_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+ struct netlink_ext_ack *extack, unsigned long *actions_done)
{
struct mlx4_priv *priv = devlink_priv(devlink);
struct mlx4_dev *dev = &priv->dev;
@@ -3960,15 +3961,20 @@ static int mlx4_devlink_reload_up(struct devlink *devlink,
int err;

err = mlx4_restart_one_up(persist->pdev, true, devlink);
- if (err)
+ if (err) {
mlx4_err(persist->dev, "mlx4_restart_one_up failed, ret=%d\n",
err);
+ return err;
+ }
+ if (actions_done)
+ *actions_done = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);

- return err;
+ return 0;
}

static const struct devlink_ops mlx4_devlink_ops = {
.port_type_set = mlx4_devlink_port_type_set,
+ .supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
.reload_down = mlx4_devlink_reload_down,
.reload_up = mlx4_devlink_reload_up,
};
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
index c709e9a385f6..e0f1a1a2c6a9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
@@ -89,6 +89,7 @@ mlx5_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
}

static int mlx5_devlink_reload_down(struct devlink *devlink, bool netns_change,
+ enum devlink_reload_action action,
struct netlink_ext_ack *extack)
{
struct mlx5_core_dev *dev = devlink_priv(devlink);
@@ -97,12 +98,19 @@ static int mlx5_devlink_reload_down(struct devlink *devlink, bool netns_change,
return 0;
}

-static int mlx5_devlink_reload_up(struct devlink *devlink,
- struct netlink_ext_ack *extack)
+static int mlx5_devlink_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+ struct netlink_ext_ack *extack, unsigned long *actions_done)
{
struct mlx5_core_dev *dev = devlink_priv(devlink);
+ int err;

- return mlx5_load_one(dev, false);
+ err = mlx5_load_one(dev, false);
+ if (err)
+ return err;
+ if (actions_done)
+ *actions_done = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
+
+ return 0;
}

static const struct devlink_ops mlx5_devlink_ops = {
@@ -118,6 +126,7 @@ static const struct devlink_ops mlx5_devlink_ops = {
#endif
.flash_update = mlx5_devlink_flash_update,
.info_get = mlx5_devlink_info_get,
+ .supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
.reload_down = mlx5_devlink_reload_down,
.reload_up = mlx5_devlink_reload_up,
};
diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
index 08d101138fbe..c42b66d88884 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -1113,7 +1113,7 @@ mlxsw_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,

static int
mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
- bool netns_change,
+ bool netns_change, enum devlink_reload_action action,
struct netlink_ext_ack *extack)
{
struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
@@ -1126,15 +1126,23 @@ mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
}

static int
-mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink,
- struct netlink_ext_ack *extack)
+mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+ struct netlink_ext_ack *extack, unsigned long *actions_done)
{
struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
+ int err;

- return mlxsw_core_bus_device_register(mlxsw_core->bus_info,
- mlxsw_core->bus,
- mlxsw_core->bus_priv, true,
- devlink, extack);
+ err = mlxsw_core_bus_device_register(mlxsw_core->bus_info,
+ mlxsw_core->bus,
+ mlxsw_core->bus_priv, true,
+ devlink, extack);
+ if (err)
+ return err;
+ if (actions_done)
+ *actions_done = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
+ BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE);
+
+ return 0;
}

static int mlxsw_devlink_flash_update(struct devlink *devlink,
@@ -1268,6 +1276,8 @@ mlxsw_devlink_trap_policer_counter_get(struct devlink *devlink,
}

static const struct devlink_ops mlxsw_devlink_ops = {
+ .supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
+ BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE),
.reload_down = mlxsw_devlink_core_bus_device_reload_down,
.reload_up = mlxsw_devlink_core_bus_device_reload_up,
.port_type_set = mlxsw_devlink_port_type_set,
diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 32f339fedb21..e2166e755659 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -697,7 +697,7 @@ static int nsim_dev_reload_create(struct nsim_dev *nsim_dev,
static void nsim_dev_reload_destroy(struct nsim_dev *nsim_dev);

static int nsim_dev_reload_down(struct devlink *devlink, bool netns_change,
- struct netlink_ext_ack *extack)
+ enum devlink_reload_action action, struct netlink_ext_ack *extack)
{
struct nsim_dev *nsim_dev = devlink_priv(devlink);

@@ -713,10 +713,11 @@ static int nsim_dev_reload_down(struct devlink *devlink, bool netns_change,
return 0;
}

-static int nsim_dev_reload_up(struct devlink *devlink,
- struct netlink_ext_ack *extack)
+static int nsim_dev_reload_up(struct devlink *devlink, enum devlink_reload_action action,
+ struct netlink_ext_ack *extack, unsigned long *actions_done)
{
struct nsim_dev *nsim_dev = devlink_priv(devlink);
+ int err;

if (nsim_dev->fail_reload) {
/* For testing purposes, user set debugfs fail_reload
@@ -726,7 +727,13 @@ static int nsim_dev_reload_up(struct devlink *devlink,
return -EINVAL;
}

- return nsim_dev_reload_create(nsim_dev, extack);
+ err = nsim_dev_reload_create(nsim_dev, extack);
+ if (err)
+ return err;
+ if (actions_done)
+ *actions_done = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
+
+ return 0;
}

static int nsim_dev_info_get(struct devlink *devlink,
@@ -875,6 +882,7 @@ nsim_dev_devlink_trap_policer_counter_get(struct devlink *devlink,
}

static const struct devlink_ops nsim_dev_devlink_ops = {
+ .supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
.reload_down = nsim_dev_reload_down,
.reload_up = nsim_dev_reload_up,
.info_get = nsim_dev_info_get,
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 8f3c8a443238..b8f0152a1fff 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -991,10 +991,11 @@ enum devlink_trap_group_generic_id {
}

struct devlink_ops {
+ unsigned long supported_reload_actions;
int (*reload_down)(struct devlink *devlink, bool netns_change,
- struct netlink_ext_ack *extack);
- int (*reload_up)(struct devlink *devlink,
- struct netlink_ext_ack *extack);
+ enum devlink_reload_action action, struct netlink_ext_ack *extack);
+ int (*reload_up)(struct devlink *devlink, enum devlink_reload_action action,
+ struct netlink_ext_ack *extack, unsigned long *actions_done);
int (*port_type_set)(struct devlink_port *devlink_port,
enum devlink_port_type port_type);
int (*port_split)(struct devlink *devlink, unsigned int port_index,
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index cfef4245ea5a..0a438135c3cf 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -272,6 +272,24 @@ enum {
DEVLINK_ATTR_TRAP_METADATA_TYPE_FA_COOKIE,
};

+/**
+ * enum devlink_reload_action - Reload action.
+ * @DEVLINK_RELOAD_ACTION_DRIVER_REINIT: Driver entities re-instantiation.
+ * @DEVLINK_RELOAD_ACTION_FW_ACTIVATE: FW activate.
+ * @DEVLINK_RELOAD_ACTION_FW_ACTIVATE_NO_RESET: Activate new FW image withouti any reset
+ * (firmware live patching).
+ */
+enum devlink_reload_action {
+ DEVLINK_RELOAD_ACTION_UNSPEC,
+ DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
+ DEVLINK_RELOAD_ACTION_FW_ACTIVATE,
+ DEVLINK_RELOAD_ACTION_FW_ACTIVATE_NO_RESET,
+
+ /* Add new reload actions above */
+ __DEVLINK_RELOAD_ACTION_MAX,
+ DEVLINK_RELOAD_ACTION_MAX = __DEVLINK_RELOAD_ACTION_MAX - 1
+};
+
enum devlink_attr {
/* don't change the order or add anything between, this is ABI! */
DEVLINK_ATTR_UNSPEC,
@@ -458,6 +476,9 @@ enum devlink_attr {
DEVLINK_ATTR_PORT_LANES, /* u32 */
DEVLINK_ATTR_PORT_SPLITTABLE, /* u8 */

+ DEVLINK_ATTR_RELOAD_ACTION, /* u8 */
+ DEVLINK_ATTR_RELOAD_ACTIONS_DONE, /* nested */
+
/* add new attributes above here, update the policy in devlink.c */

__DEVLINK_ATTR_MAX,
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 58c8bb07fa19..8d4137ad40db 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -462,6 +462,12 @@ static int devlink_nl_put_handle(struct sk_buff *msg, struct devlink *devlink)
return 0;
}

+static bool
+devlink_reload_action_is_supported(struct devlink *devlink, enum devlink_reload_action action)
+{
+ return test_bit(action, &devlink->ops->supported_reload_actions);
+}
+
static int devlink_nl_fill(struct sk_buff *msg, struct devlink *devlink,
enum devlink_command cmd, u32 portid,
u32 seq, int flags)
@@ -2964,29 +2970,72 @@ bool devlink_is_reload_failed(const struct devlink *devlink)
EXPORT_SYMBOL_GPL(devlink_is_reload_failed);

static int devlink_reload(struct devlink *devlink, struct net *dest_net,
- struct netlink_ext_ack *extack)
+ enum devlink_reload_action action, struct netlink_ext_ack *extack,
+ unsigned long *actions_done)
{
int err;

if (!devlink->reload_enabled)
return -EOPNOTSUPP;

- err = devlink->ops->reload_down(devlink, !!dest_net, extack);
+ err = devlink->ops->reload_down(devlink, !!dest_net, action, extack);
if (err)
return err;

if (dest_net && !net_eq(dest_net, devlink_net(devlink)))
devlink_reload_netns_change(devlink, dest_net);

- err = devlink->ops->reload_up(devlink, extack);
+ err = devlink->ops->reload_up(devlink, action, extack, actions_done);
devlink_reload_failed_set(devlink, !!err);
return err;
}

+static int
+devlink_nl_reload_actions_done_fill(struct sk_buff *msg,
+ struct devlink *devlink,
+ unsigned long actions_done,
+ enum devlink_command cmd, u32 portid,
+ u32 seq, int flags)
+{
+ struct nlattr *actions_done_attr;
+ void *hdr;
+ int i;
+
+ hdr = genlmsg_put(msg, portid, seq, &devlink_nl_family, flags, cmd);
+ if (!hdr)
+ return -EMSGSIZE;
+
+ if (devlink_nl_put_handle(msg, devlink))
+ goto genlmsg_cancel;
+
+ actions_done_attr = nla_nest_start(msg, DEVLINK_ATTR_RELOAD_ACTIONS_DONE);
+ if (!actions_done_attr)
+ goto genlmsg_cancel;
+
+ for (i = 0; i <= DEVLINK_RELOAD_ACTION_MAX; i++) {
+ if (!test_bit(i, &actions_done))
+ continue;
+ if (nla_put_u8(msg, DEVLINK_ATTR_RELOAD_ACTION, i))
+ goto actions_done_nest_cancel;
+ }
+ nla_nest_end(msg, actions_done_attr);
+ genlmsg_end(msg, hdr);
+ return 0;
+
+actions_done_nest_cancel:
+ nla_nest_cancel(msg, actions_done_attr);
+genlmsg_cancel:
+ genlmsg_cancel(msg, hdr);
+ return -EMSGSIZE;
+}
+
static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
{
struct devlink *devlink = info->user_ptr[0];
+ enum devlink_reload_action action;
struct net *dest_net = NULL;
+ unsigned long actions_done;
+ struct sk_buff *msg;
int err;

if (!devlink_reload_supported(devlink))
@@ -3006,12 +3055,42 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
return PTR_ERR(dest_net);
}

- err = devlink_reload(devlink, dest_net, info->extack);
+ if (info->attrs[DEVLINK_ATTR_RELOAD_ACTION])
+ action = nla_get_u8(info->attrs[DEVLINK_ATTR_RELOAD_ACTION]);
+ else
+ action = DEVLINK_RELOAD_ACTION_DRIVER_REINIT;
+
+ if (action == DEVLINK_RELOAD_ACTION_UNSPEC || action > DEVLINK_RELOAD_ACTION_MAX) {
+ NL_SET_ERR_MSG_MOD(info->extack, "Invalid reload action");
+ return -EINVAL;
+ } else if (!devlink_reload_action_is_supported(devlink, action)) {
+ NL_SET_ERR_MSG_MOD(info->extack, "Requested reload action is not supported");
+ return -EOPNOTSUPP;
+ }
+
+ err = devlink_reload(devlink, dest_net, action, info->extack, &actions_done);

if (dest_net)
put_net(dest_net);

- return err;
+ if (err)
+ return err;
+
+ WARN_ON(!actions_done);
+ if (action == DEVLINK_RELOAD_ACTION_FW_ACTIVATE_NO_RESET)
+ WARN_ON(actions_done != BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE_NO_RESET));
+ msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ err = devlink_nl_reload_actions_done_fill(msg, devlink, actions_done, DEVLINK_CMD_RELOAD,
+ info->snd_portid, info->snd_seq, 0);
+ if (err) {
+ nlmsg_free(msg);
+ return err;
+ }
+
+ return genlmsg_reply(msg, info);
}

static int devlink_nl_flash_update_fill(struct sk_buff *msg,
@@ -7042,6 +7121,7 @@ static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
[DEVLINK_ATTR_TRAP_POLICER_RATE] = { .type = NLA_U64 },
[DEVLINK_ATTR_TRAP_POLICER_BURST] = { .type = NLA_U64 },
[DEVLINK_ATTR_PORT_FUNCTION] = { .type = NLA_NESTED },
+ [DEVLINK_ATTR_RELOAD_ACTION] = { .type = NLA_U8 },
};

static const struct genl_ops devlink_nl_ops[] = {
@@ -7367,6 +7447,20 @@ static struct genl_family devlink_nl_family __ro_after_init = {
.n_mcgrps = ARRAY_SIZE(devlink_nl_mcgrps),
};

+static int devlink_reload_actions_verify(struct devlink *devlink)
+{
+ const struct devlink_ops *ops;
+
+ if (!devlink_reload_supported(devlink))
+ return 0;
+
+ ops = devlink->ops;
+ if (WARN_ON(ops->supported_reload_actions >= BIT(__DEVLINK_RELOAD_ACTION_MAX) ||
+ ops->supported_reload_actions <= BIT(DEVLINK_RELOAD_ACTION_UNSPEC)))
+ return -EINVAL;
+ return 0;
+}
+
/**
* devlink_alloc - Allocate new devlink instance resources
*
@@ -7387,6 +7481,11 @@ struct devlink *devlink_alloc(const struct devlink_ops *ops, size_t priv_size)
if (!devlink)
return NULL;
devlink->ops = ops;
+ if (devlink_reload_actions_verify(devlink)) {
+ kfree(devlink);
+ return NULL;
+ }
+
xa_init_flags(&devlink->snapshot_ids, XA_FLAGS_ALLOC);
__devlink_net_set(devlink, &init_net);
INIT_LIST_HEAD(&devlink->port_list);
@@ -9618,7 +9717,8 @@ static void __net_exit devlink_pernet_pre_exit(struct net *net)
if (net_eq(devlink_net(devlink), net)) {
if (WARN_ON(!devlink_reload_supported(devlink)))
continue;
- err = devlink_reload(devlink, &init_net, NULL);
+ err = devlink_reload(devlink, &init_net,
+ DEVLINK_RELOAD_ACTION_DRIVER_REINIT, NULL, NULL);
if (err && err != -EOPNOTSUPP)
pr_warn("Failed to reload devlink instance into init_net\n");
}
--
2.17.1


2020-08-31 12:16:54

by Jiri Pirko

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

Sun, Aug 30, 2020 at 05:27:21PM CEST, [email protected] wrote:
>Add devlink reload action to allow the user to request a specific reload
>action. The action parameter is optional, if not specified then devlink
>driver re-init action is used (backward compatible).
>Note that when required to do firmware activation some drivers may need
>to reload the driver. On the other hand some drivers may need to reset
>the firmware to reinitialize the driver entities. Therefore, the devlink
>reload command returns the actions which were actually done.
>However, in case fw_activate_no_reset action is selected, then no other
>reload action is allowed.
>Reload actions supported are:
>driver_reinit: driver entities re-initialization, applying devlink-param
> and devlink-resource values.
>fw_activate: firmware activate.
>fw_activate_no_reset: Activate new firmware image without any reset.
> (also known as: firmware live patching).
>
>command examples:
>$devlink dev reload pci/0000:82:00.0 action driver_reinit
>reload_actions_done:
> driver_reinit
>
>$devlink dev reload pci/0000:82:00.0 action fw_activate
>reload_actions_done:
> driver_reinit fw_activate
>
>Signed-off-by: Moshe Shemesh <[email protected]>
>---
>v2 -> v3:
>- Replace fw_live_patch action by fw_activate_no_reset
>- Devlink reload returns the actions done over netlink reply
>v1 -> v2:
>- Instead of reload levels driver,fw_reset,fw_live_patch have reload
> actions driver_reinit,fw_activate,fw_live_patch
>- Remove driver default level, the action driver_reinit is the default
> action for all drivers
>---

[...]


>diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
>index 08d101138fbe..c42b66d88884 100644
>--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
>+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
>@@ -1113,7 +1113,7 @@ mlxsw_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
>
> static int
> mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
>- bool netns_change,
>+ bool netns_change, enum devlink_reload_action action,
> struct netlink_ext_ack *extack)
> {
> struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
>@@ -1126,15 +1126,23 @@ mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
> }
>
> static int
>-mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink,
>- struct netlink_ext_ack *extack)
>+mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink, enum devlink_reload_action action,
>+ struct netlink_ext_ack *extack, unsigned long *actions_done)
> {
> struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
>+ int err;
>
>- return mlxsw_core_bus_device_register(mlxsw_core->bus_info,
>- mlxsw_core->bus,
>- mlxsw_core->bus_priv, true,
>- devlink, extack);
>+ err = mlxsw_core_bus_device_register(mlxsw_core->bus_info,
>+ mlxsw_core->bus,
>+ mlxsw_core->bus_priv, true,
>+ devlink, extack);
>+ if (err)
>+ return err;
>+ if (actions_done)
>+ *actions_done = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
>+ BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE);
>+
>+ return 0;
> }
>
> static int mlxsw_devlink_flash_update(struct devlink *devlink,
>@@ -1268,6 +1276,8 @@ mlxsw_devlink_trap_policer_counter_get(struct devlink *devlink,
> }
>
> static const struct devlink_ops mlxsw_devlink_ops = {
>+ .supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
>+ BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE),

This is confusing and open to interpretation. Does this mean that the
driver supports:
1) REINIT && FW_ACTIVATE
2) REINIT || FW_ACTIVATE
?

Because mlxsw supports only 1. I guess that mlx5 supports both. This
needs to be distinguished.

I think you need an array of combinations. Or perhaps rather to extend
the enum with combinations. You kind of have it already with
DEVLINK_RELOAD_ACTION_FW_ACTIVATE_NO_RESET

Maybe we can have something like:
DEVLINK_RELOAD_ACTION_DRIVER_REINIT
DEVLINK_RELOAD_ACTION_DRIVER_REINIT_FW_ACTIVATE_RESET
DEVLINK_RELOAD_ACTION_FW_ACTIVATE_RESET
DEVLINK_RELOAD_ACTION_FW_ACTIVATE (this is the original FW_ACTIVATE_NO_RESET)

Each has very clear meaning.

Also, then the "actions_done" would be a simple enum, directly returned
to the user. No bitfield needed.


> .reload_down = mlxsw_devlink_core_bus_device_reload_down,
> .reload_up = mlxsw_devlink_core_bus_device_reload_up,
> .port_type_set = mlxsw_devlink_port_type_set,

[...]

2020-09-01 19:48:04

by Moshe Shemesh

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command


On 8/31/2020 3:15 PM, Jiri Pirko wrote:
> Sun, Aug 30, 2020 at 05:27:21PM CEST, [email protected] wrote:
>> Add devlink reload action to allow the user to request a specific reload
>> action. The action parameter is optional, if not specified then devlink
>> driver re-init action is used (backward compatible).
>> Note that when required to do firmware activation some drivers may need
>> to reload the driver. On the other hand some drivers may need to reset
>> the firmware to reinitialize the driver entities. Therefore, the devlink
>> reload command returns the actions which were actually done.
>> However, in case fw_activate_no_reset action is selected, then no other
>> reload action is allowed.
>> Reload actions supported are:
>> driver_reinit: driver entities re-initialization, applying devlink-param
>> and devlink-resource values.
>> fw_activate: firmware activate.
>> fw_activate_no_reset: Activate new firmware image without any reset.
>> (also known as: firmware live patching).
>>
>> command examples:
>> $devlink dev reload pci/0000:82:00.0 action driver_reinit
>> reload_actions_done:
>> driver_reinit
>>
>> $devlink dev reload pci/0000:82:00.0 action fw_activate
>> reload_actions_done:
>> driver_reinit fw_activate
>>
>> Signed-off-by: Moshe Shemesh <[email protected]>
>> ---
>> v2 -> v3:
>> - Replace fw_live_patch action by fw_activate_no_reset
>> - Devlink reload returns the actions done over netlink reply
>> v1 -> v2:
>> - Instead of reload levels driver,fw_reset,fw_live_patch have reload
>> actions driver_reinit,fw_activate,fw_live_patch
>> - Remove driver default level, the action driver_reinit is the default
>> action for all drivers
>> ---
> [...]
>
>
>> diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
>> index 08d101138fbe..c42b66d88884 100644
>> --- a/drivers/net/ethernet/mellanox/mlxsw/core.c
>> +++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
>> @@ -1113,7 +1113,7 @@ mlxsw_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
>>
>> static int
>> mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
>> - bool netns_change,
>> + bool netns_change, enum devlink_reload_action action,
>> struct netlink_ext_ack *extack)
>> {
>> struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
>> @@ -1126,15 +1126,23 @@ mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
>> }
>>
>> static int
>> -mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink,
>> - struct netlink_ext_ack *extack)
>> +mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink, enum devlink_reload_action action,
>> + struct netlink_ext_ack *extack, unsigned long *actions_done)
>> {
>> struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
>> + int err;
>>
>> - return mlxsw_core_bus_device_register(mlxsw_core->bus_info,
>> - mlxsw_core->bus,
>> - mlxsw_core->bus_priv, true,
>> - devlink, extack);
>> + err = mlxsw_core_bus_device_register(mlxsw_core->bus_info,
>> + mlxsw_core->bus,
>> + mlxsw_core->bus_priv, true,
>> + devlink, extack);
>> + if (err)
>> + return err;
>> + if (actions_done)
>> + *actions_done = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
>> + BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE);
>> +
>> + return 0;
>> }
>>
>> static int mlxsw_devlink_flash_update(struct devlink *devlink,
>> @@ -1268,6 +1276,8 @@ mlxsw_devlink_trap_policer_counter_get(struct devlink *devlink,
>> }
>>
>> static const struct devlink_ops mlxsw_devlink_ops = {
>> + .supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
>> + BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE),
> This is confusing and open to interpretation. Does this mean that the
> driver supports:
> 1) REINIT && FW_ACTIVATE
> 2) REINIT || FW_ACTIVATE
> ?
>
> Because mlxsw supports only 1. I guess that mlx5 supports both. This
> needs to be distinguished.

Mlxsw supports 1, so it supports fw_activation and performs also reinit
and vice versa.

Mlx5 supports fw_activate and performs also reinit. However, it supports
reinit without performing fw_activate.

> I think you need an array of combinations. Or perhaps rather to extend
> the enum with combinations. You kind of have it already with
> DEVLINK_RELOAD_ACTION_FW_ACTIVATE_NO_RESET
>
> Maybe we can have something like:
> DEVLINK_RELOAD_ACTION_DRIVER_REINIT
> DEVLINK_RELOAD_ACTION_DRIVER_REINIT_FW_ACTIVATE_RESET
> DEVLINK_RELOAD_ACTION_FW_ACTIVATE_RESET
> DEVLINK_RELOAD_ACTION_FW_ACTIVATE (this is the original FW_ACTIVATE_NO_RESET)

The FW_ACTIVATE_NO_RESET meant also to emphasize that driver
implementation for this one should not do any reset.

So maybe we can have

DEVLINK_RELOAD_ACTION_FW_ACTIVATE_RESET
DEVLINK_RELOAD_ACTION_FW_ACTIVATE_NO_RESET

> Each has very clear meaning.


Yes, it the driver support here is more clear.

> Also, then the "actions_done" would be a simple enum, directly returned
> to the user. No bitfield needed.


I agree it is more clear on the driver support side, but what about the
uAPI ? Do we need such change there too or keep it as is, each action by
itself and return what was performed ?

>
>> .reload_down = mlxsw_devlink_core_bus_device_reload_down,
>> .reload_up = mlxsw_devlink_core_bus_device_reload_up,
>> .port_type_set = mlxsw_devlink_port_type_set,
> [...]

2020-09-02 09:48:05

by Jiri Pirko

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

Tue, Sep 01, 2020 at 09:43:00PM CEST, [email protected] wrote:
>
>On 8/31/2020 3:15 PM, Jiri Pirko wrote:
>> Sun, Aug 30, 2020 at 05:27:21PM CEST, [email protected] wrote:
>> > Add devlink reload action to allow the user to request a specific reload
>> > action. The action parameter is optional, if not specified then devlink
>> > driver re-init action is used (backward compatible).
>> > Note that when required to do firmware activation some drivers may need
>> > to reload the driver. On the other hand some drivers may need to reset
>> > the firmware to reinitialize the driver entities. Therefore, the devlink
>> > reload command returns the actions which were actually done.
>> > However, in case fw_activate_no_reset action is selected, then no other
>> > reload action is allowed.
>> > Reload actions supported are:
>> > driver_reinit: driver entities re-initialization, applying devlink-param
>> > and devlink-resource values.
>> > fw_activate: firmware activate.
>> > fw_activate_no_reset: Activate new firmware image without any reset.
>> > (also known as: firmware live patching).
>> >
>> > command examples:
>> > $devlink dev reload pci/0000:82:00.0 action driver_reinit
>> > reload_actions_done:
>> > driver_reinit
>> >
>> > $devlink dev reload pci/0000:82:00.0 action fw_activate
>> > reload_actions_done:
>> > driver_reinit fw_activate
>> >
>> > Signed-off-by: Moshe Shemesh <[email protected]>
>> > ---
>> > v2 -> v3:
>> > - Replace fw_live_patch action by fw_activate_no_reset
>> > - Devlink reload returns the actions done over netlink reply
>> > v1 -> v2:
>> > - Instead of reload levels driver,fw_reset,fw_live_patch have reload
>> > actions driver_reinit,fw_activate,fw_live_patch
>> > - Remove driver default level, the action driver_reinit is the default
>> > action for all drivers
>> > ---
>> [...]
>>
>>
>> > diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
>> > index 08d101138fbe..c42b66d88884 100644
>> > --- a/drivers/net/ethernet/mellanox/mlxsw/core.c
>> > +++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
>> > @@ -1113,7 +1113,7 @@ mlxsw_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
>> >
>> > static int
>> > mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
>> > - bool netns_change,
>> > + bool netns_change, enum devlink_reload_action action,
>> > struct netlink_ext_ack *extack)
>> > {
>> > struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
>> > @@ -1126,15 +1126,23 @@ mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
>> > }
>> >
>> > static int
>> > -mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink,
>> > - struct netlink_ext_ack *extack)
>> > +mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink, enum devlink_reload_action action,
>> > + struct netlink_ext_ack *extack, unsigned long *actions_done)
>> > {
>> > struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
>> > + int err;
>> >
>> > - return mlxsw_core_bus_device_register(mlxsw_core->bus_info,
>> > - mlxsw_core->bus,
>> > - mlxsw_core->bus_priv, true,
>> > - devlink, extack);
>> > + err = mlxsw_core_bus_device_register(mlxsw_core->bus_info,
>> > + mlxsw_core->bus,
>> > + mlxsw_core->bus_priv, true,
>> > + devlink, extack);
>> > + if (err)
>> > + return err;
>> > + if (actions_done)
>> > + *actions_done = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
>> > + BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE);
>> > +
>> > + return 0;
>> > }
>> >
>> > static int mlxsw_devlink_flash_update(struct devlink *devlink,
>> > @@ -1268,6 +1276,8 @@ mlxsw_devlink_trap_policer_counter_get(struct devlink *devlink,
>> > }
>> >
>> > static const struct devlink_ops mlxsw_devlink_ops = {
>> > + .supported_reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
>> > + BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE),
>> This is confusing and open to interpretation. Does this mean that the
>> driver supports:
>> 1) REINIT && FW_ACTIVATE
>> 2) REINIT || FW_ACTIVATE
>> ?
>>
>> Because mlxsw supports only 1. I guess that mlx5 supports both. This
>> needs to be distinguished.
>
>Mlxsw supports 1, so it supports fw_activation and performs also reinit and
>vice versa.

My point is, your bitfield does not exactly tell what the driver
supports or not.


>
>Mlx5 supports fw_activate and performs also reinit. However, it supports
>reinit without performing fw_activate.
>
>> I think you need an array of combinations. Or perhaps rather to extend
>> the enum with combinations. You kind of have it already with
>> DEVLINK_RELOAD_ACTION_FW_ACTIVATE_NO_RESET
>>
>> Maybe we can have something like:
>> DEVLINK_RELOAD_ACTION_DRIVER_REINIT
>> DEVLINK_RELOAD_ACTION_DRIVER_REINIT_FW_ACTIVATE_RESET
>> DEVLINK_RELOAD_ACTION_FW_ACTIVATE_RESET
>> DEVLINK_RELOAD_ACTION_FW_ACTIVATE (this is the original FW_ACTIVATE_NO_RESET)
>
>The FW_ACTIVATE_NO_RESET meant also to emphasize that driver implementation
>for this one should not do any reset.
>
>So maybe we can have
>
>DEVLINK_RELOAD_ACTION_FW_ACTIVATE_RESET
>DEVLINK_RELOAD_ACTION_FW_ACTIVATE_NO_RESET

Okay.


>
>> Each has very clear meaning.
>
>
>Yes, it the driver support here is more clear.
>
>> Also, then the "actions_done" would be a simple enum, directly returned
>> to the user. No bitfield needed.
>
>
>I agree it is more clear on the driver support side, but what about the uAPI

As I said, there would be one enum value returned to the user. Clear and
simple.


>? Do we need such change there too or keep it as is, each action by itself
>and return what was performed ?

Well, I don't know. User asks for X, X should be performed, not Y or Z.
So perhaps the return value is not needed.
Just driver advertizes it supports X, Y, Z and the users says:
1) do X, driver does X
2) do Y, driver does Y
3) do Z, driver does Z
[
I think this kindof circles back to the original proposal...

>
>>
>> > .reload_down = mlxsw_devlink_core_bus_device_reload_down,
>> > .reload_up = mlxsw_devlink_core_bus_device_reload_up,
>> > .port_type_set = mlxsw_devlink_port_type_set,
>> [...]

2020-09-02 15:33:21

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

On Wed, 2 Sep 2020 11:46:27 +0200 Jiri Pirko wrote:
> >? Do we need such change there too or keep it as is, each action by itself
> >and return what was performed ?
>
> Well, I don't know. User asks for X, X should be performed, not Y or Z.
> So perhaps the return value is not needed.
> Just driver advertizes it supports X, Y, Z and the users says:
> 1) do X, driver does X
> 2) do Y, driver does Y
> 3) do Z, driver does Z
> [
> I think this kindof circles back to the original proposal...

Why? User does not care if you activate new devlink params when
activating new firmware. Trust me. So why make the user figure out
which of all possible reset option they should select? If there is
a legitimate use case to limit what is reset - it should be handled
by a separate negative attribute, like --live which says don't reset
anything.

2020-09-03 05:59:37

by Jiri Pirko

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

Wed, Sep 02, 2020 at 05:30:25PM CEST, [email protected] wrote:
>On Wed, 2 Sep 2020 11:46:27 +0200 Jiri Pirko wrote:
>> >? Do we need such change there too or keep it as is, each action by itself
>> >and return what was performed ?
>>
>> Well, I don't know. User asks for X, X should be performed, not Y or Z.
>> So perhaps the return value is not needed.
>> Just driver advertizes it supports X, Y, Z and the users says:
>> 1) do X, driver does X
>> 2) do Y, driver does Y
>> 3) do Z, driver does Z
>> [
>> I think this kindof circles back to the original proposal...
>
>Why? User does not care if you activate new devlink params when
>activating new firmware. Trust me. So why make the user figure out
>which of all possible reset option they should select? If there is
>a legitimate use case to limit what is reset - it should be handled
>by a separate negative attribute, like --live which says don't reset
>anything.

I see. Okay. Could you please sum-up the interface as you propose it?
Thanks!

2020-09-03 19:50:52

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

On Thu, 3 Sep 2020 07:57:29 +0200 Jiri Pirko wrote:
> Wed, Sep 02, 2020 at 05:30:25PM CEST, [email protected] wrote:
> >On Wed, 2 Sep 2020 11:46:27 +0200 Jiri Pirko wrote:
> >> >? Do we need such change there too or keep it as is, each action by itself
> >> >and return what was performed ?
> >>
> >> Well, I don't know. User asks for X, X should be performed, not Y or Z.
> >> So perhaps the return value is not needed.
> >> Just driver advertizes it supports X, Y, Z and the users says:
> >> 1) do X, driver does X
> >> 2) do Y, driver does Y
> >> 3) do Z, driver does Z
> >> [
> >> I think this kindof circles back to the original proposal...
> >
> >Why? User does not care if you activate new devlink params when
> >activating new firmware. Trust me. So why make the user figure out
> >which of all possible reset option they should select? If there is
> >a legitimate use case to limit what is reset - it should be handled
> >by a separate negative attribute, like --live which says don't reset
> >anything.
>
> I see. Okay. Could you please sum-up the interface as you propose it?

What I proposed on v1, pass requested actions as a bitfield, driver may
perform more actions, we can return performed actions in the response.

Then separate attribute to carry constraints for the request, like
--live.

I'd think the supported actions in devlink_ops would be fine as a
bitfield, too. Combinations are often hard to capture in static data.

2020-09-04 09:06:25

by Jiri Pirko

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

Thu, Sep 03, 2020 at 09:47:19PM CEST, [email protected] wrote:
>On Thu, 3 Sep 2020 07:57:29 +0200 Jiri Pirko wrote:
>> Wed, Sep 02, 2020 at 05:30:25PM CEST, [email protected] wrote:
>> >On Wed, 2 Sep 2020 11:46:27 +0200 Jiri Pirko wrote:
>> >> >? Do we need such change there too or keep it as is, each action by itself
>> >> >and return what was performed ?
>> >>
>> >> Well, I don't know. User asks for X, X should be performed, not Y or Z.
>> >> So perhaps the return value is not needed.
>> >> Just driver advertizes it supports X, Y, Z and the users says:
>> >> 1) do X, driver does X
>> >> 2) do Y, driver does Y
>> >> 3) do Z, driver does Z
>> >> [
>> >> I think this kindof circles back to the original proposal...
>> >
>> >Why? User does not care if you activate new devlink params when
>> >activating new firmware. Trust me. So why make the user figure out
>> >which of all possible reset option they should select? If there is
>> >a legitimate use case to limit what is reset - it should be handled
>> >by a separate negative attribute, like --live which says don't reset
>> >anything.
>>
>> I see. Okay. Could you please sum-up the interface as you propose it?
>
>What I proposed on v1, pass requested actions as a bitfield, driver may
>perform more actions, we can return performed actions in the response.

Okay. So for example for mlxsw, user might say:
1) I want driver reinit
kernel reports: fw reset and driver reinit was done
2) I want fw reset
kernel reports: fw reset and driver reinit was done
3) I want fw reset and driver reinit
kernel reports: fw reset and driver reinit was done

>
>Then separate attribute to carry constraints for the request, like
>--live.

Hmm, this is a bit unclear how it is supposed to work. The constraints
apply for all? I mean, the actions are requested by a bitfield.
So the user can say:
I want fw reset and driver reinit --live. "--live" applies to both fw
reset and driver reinit? That is odd.

>
>I'd think the supported actions in devlink_ops would be fine as a
>bitfield, too. Combinations are often hard to capture in static data.

2020-09-04 19:59:03

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

On Fri, 4 Sep 2020 11:04:50 +0200 Jiri Pirko wrote:
> Thu, Sep 03, 2020 at 09:47:19PM CEST, [email protected] wrote:
> >On Thu, 3 Sep 2020 07:57:29 +0200 Jiri Pirko wrote:
> >> Wed, Sep 02, 2020 at 05:30:25PM CEST, [email protected] wrote:
> >> >On Wed, 2 Sep 2020 11:46:27 +0200 Jiri Pirko wrote:
> >> >> >? Do we need such change there too or keep it as is, each action by itself
> >> >> >and return what was performed ?
> >> >>
> >> >> Well, I don't know. User asks for X, X should be performed, not Y or Z.
> >> >> So perhaps the return value is not needed.
> >> >> Just driver advertizes it supports X, Y, Z and the users says:
> >> >> 1) do X, driver does X
> >> >> 2) do Y, driver does Y
> >> >> 3) do Z, driver does Z
> >> >> [
> >> >> I think this kindof circles back to the original proposal...
> >> >
> >> >Why? User does not care if you activate new devlink params when
> >> >activating new firmware. Trust me. So why make the user figure out
> >> >which of all possible reset option they should select? If there is
> >> >a legitimate use case to limit what is reset - it should be handled
> >> >by a separate negative attribute, like --live which says don't reset
> >> >anything.
> >>
> >> I see. Okay. Could you please sum-up the interface as you propose it?
> >
> >What I proposed on v1, pass requested actions as a bitfield, driver may
> >perform more actions, we can return performed actions in the response.
>
> Okay. So for example for mlxsw, user might say:
> 1) I want driver reinit
> kernel reports: fw reset and driver reinit was done
> 2) I want fw reset
> kernel reports: fw reset and driver reinit was done
> 3) I want fw reset and driver reinit
> kernel reports: fw reset and driver reinit was done

Yup.

> >Then separate attribute to carry constraints for the request, like
> >--live.
>
> Hmm, this is a bit unclear how it is supposed to work. The constraints
> apply for all? I mean, the actions are requested by a bitfield.
> So the user can say:
> I want fw reset and driver reinit --live. "--live" applies to both fw
> reset and driver reinit? That is odd.

The way I was thinking about it - the constraint expresses what sort of
downtime the user can accept. So yes, it'd apply to all. If any of the
reset actions does not meet the constraint then error should be
returned.

In that sense I don't like --live because it doesn't really say much.
AFAIU it means 1) no link flap; 2) < 2 sec datapath downtime; 3) no
configuration is lost in kernel or device (including netdev config,
link config, flow rules, counters etc.). I was hoping at least the
documentation in patch 14 would be more precise.

I think you're saying that it's strange to express that as a constraint
because internally it maps to one of two fw reset types. And there is
only one driver reinit procedure. But I don't think that the
distinction of reset types is valuable to the user. What matters is if
application SLAs will be met or not.

I assume that deeper/longer reset is always less risky and would be
preferred unless constraint is specified.

> >I'd think the supported actions in devlink_ops would be fine as a
> >bitfield, too. Combinations are often hard to capture in static data.

2020-09-07 17:23:20

by Moshe Shemesh

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command


On 9/4/2020 10:56 PM, Jakub Kicinski wrote:
> External email: Use caution opening links or attachments
>
>
> On Fri, 4 Sep 2020 11:04:50 +0200 Jiri Pirko wrote:
>> Thu, Sep 03, 2020 at 09:47:19PM CEST, [email protected] wrote:
>>> On Thu, 3 Sep 2020 07:57:29 +0200 Jiri Pirko wrote:
>>>> Wed, Sep 02, 2020 at 05:30:25PM CEST, [email protected] wrote:
>>>>> On Wed, 2 Sep 2020 11:46:27 +0200 Jiri Pirko wrote:
>>>>>>> ? Do we need such change there too or keep it as is, each action by itself
>>>>>>> and return what was performed ?
>>>>>> Well, I don't know. User asks for X, X should be performed, not Y or Z.
>>>>>> So perhaps the return value is not needed.
>>>>>> Just driver advertizes it supports X, Y, Z and the users says:
>>>>>> 1) do X, driver does X
>>>>>> 2) do Y, driver does Y
>>>>>> 3) do Z, driver does Z
>>>>>> [
>>>>>> I think this kindof circles back to the original proposal...
>>>>> Why? User does not care if you activate new devlink params when
>>>>> activating new firmware. Trust me. So why make the user figure out
>>>>> which of all possible reset option they should select? If there is
>>>>> a legitimate use case to limit what is reset - it should be handled
>>>>> by a separate negative attribute, like --live which says don't reset
>>>>> anything.
>>>> I see. Okay. Could you please sum-up the interface as you propose it?
>>> What I proposed on v1, pass requested actions as a bitfield, driver may
>>> perform more actions, we can return performed actions in the response.
>> Okay. So for example for mlxsw, user might say:
>> 1) I want driver reinit
>> kernel reports: fw reset and driver reinit was done
>> 2) I want fw reset
>> kernel reports: fw reset and driver reinit was done
>> 3) I want fw reset and driver reinit
>> kernel reports: fw reset and driver reinit was done
> Yup.
>
>>> Then separate attribute to carry constraints for the request, like
>>> --live.
>> Hmm, this is a bit unclear how it is supposed to work. The constraints
>> apply for all? I mean, the actions are requested by a bitfield.
>> So the user can say:
>> I want fw reset and driver reinit --live. "--live" applies to both fw
>> reset and driver reinit? That is odd.
> The way I was thinking about it - the constraint expresses what sort of
> downtime the user can accept. So yes, it'd apply to all. If any of the
> reset actions does not meet the constraint then error should be
> returned.
>
> In that sense I don't like --live because it doesn't really say much.
> AFAIU it means 1) no link flap; 2) < 2 sec datapath downtime; 3) no
> configuration is lost in kernel or device (including netdev config,
> link config, flow rules, counters etc.). I was hoping at least the
> documentation in patch 14 would be more precise.


Actually, while writing "no-reset" or "live-patching" I meant also no
downtime at all and nothing resets (config, rules ... anything), that
fits mlx5 live-patching.

However, to make it more generic,  I can allow few seconds downtime and
add similar constrains as you mentioned here to "no-reset". I will add
that to the documentation patch.

> I think you're saying that it's strange to express that as a constraint
> because internally it maps to one of two fw reset types. And there is
> only one driver reinit procedure. But I don't think that the
> distinction of reset types is valuable to the user. What matters is if
> application SLAs will be met or not.
>
> I assume that deeper/longer reset is always less risky and would be
> preferred unless constraint is specified.
>
>>> I'd think the supported actions in devlink_ops would be fine as a
>>> bitfield, too. Combinations are often hard to capture in static data.

2020-09-07 18:02:29

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

On Mon, 7 Sep 2020 16:46:01 +0300 Moshe Shemesh wrote:
> > In that sense I don't like --live because it doesn't really say much.
> > AFAIU it means 1) no link flap; 2) < 2 sec datapath downtime; 3) no
> > configuration is lost in kernel or device (including netdev config,
> > link config, flow rules, counters etc.). I was hoping at least the
> > documentation in patch 14 would be more precise.
>
> Actually, while writing "no-reset" or "live-patching" I meant also no
> downtime at all and nothing resets (config, rules ... anything), that
> fits mlx5 live-patching.
>
> However, to make it more generic,  I can allow few seconds downtime and
> add similar constrains as you mentioned here to "no-reset". I will add
> that to the documentation patch.

Oh! If your device supports no downtime and packet loss at all that's
great. You don't have to weaken the definition now, whoever needs a
weaker definition can add a different constraint level later, no?

2020-09-09 17:22:43

by Moshe Shemesh

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command


On 9/7/2020 8:58 PM, Jakub Kicinski wrote:
> On Mon, 7 Sep 2020 16:46:01 +0300 Moshe Shemesh wrote:
>>> In that sense I don't like --live because it doesn't really say much.
>>> AFAIU it means 1) no link flap; 2) < 2 sec datapath downtime; 3) no
>>> configuration is lost in kernel or device (including netdev config,
>>> link config, flow rules, counters etc.). I was hoping at least the
>>> documentation in patch 14 would be more precise.
>> Actually, while writing "no-reset" or "live-patching" I meant also no
>> downtime at all and nothing resets (config, rules ... anything), that
>> fits mlx5 live-patching.
>>
>> However, to make it more generic, I can allow few seconds downtime and
>> add similar constrains as you mentioned here to "no-reset". I will add
>> that to the documentation patch.
> Oh! If your device supports no downtime and packet loss at all that's
> great. You don't have to weaken the definition now, whoever needs a
> weaker definition can add a different constraint level later, no?


Yes, but if we are thinking there will be more levels, maybe the flag
"--live" or "--no_reset" is less extendable, we may need new attr. I
mean should I have uAPI command line like:

$ devlink dev reload DEV [ netns { PID | NAME | ID } ] [ action {
driver_reinit | fw_activate } [ limit_level  no_reset ] ]


2020-09-09 19:25:22

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

On Wed, 9 Sep 2020 16:27:19 +0300 Moshe Shemesh wrote:
> On 9/7/2020 8:58 PM, Jakub Kicinski wrote:
> > On Mon, 7 Sep 2020 16:46:01 +0300 Moshe Shemesh wrote:
> >>> In that sense I don't like --live because it doesn't really say much.
> >>> AFAIU it means 1) no link flap; 2) < 2 sec datapath downtime; 3) no
> >>> configuration is lost in kernel or device (including netdev config,
> >>> link config, flow rules, counters etc.). I was hoping at least the
> >>> documentation in patch 14 would be more precise.
> >> Actually, while writing "no-reset" or "live-patching" I meant also no
> >> downtime at all and nothing resets (config, rules ... anything), that
> >> fits mlx5 live-patching.
> >>
> >> However, to make it more generic, I can allow few seconds downtime and
> >> add similar constrains as you mentioned here to "no-reset". I will add
> >> that to the documentation patch.
> > Oh! If your device supports no downtime and packet loss at all that's
> > great. You don't have to weaken the definition now, whoever needs a
> > weaker definition can add a different constraint level later, no?
>
> Yes, but if we are thinking there will be more levels, maybe the flag
> "--live" or "--no_reset" is less extendable, we may need new attr. I
> mean should I have uAPI command line like:
>
> $ devlink dev reload DEV [ netns { PID | NAME | ID } ] [ action {
> driver_reinit | fw_activate } [ limit_level  no_reset ] ]

That LGTM, thanks.

2020-09-10 05:19:02

by Vasundhara Volam

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

On Wed, Sep 9, 2020 at 10:51 PM Moshe Shemesh <[email protected]> wrote:
>
>
> On 9/7/2020 8:58 PM, Jakub Kicinski wrote:
> > On Mon, 7 Sep 2020 16:46:01 +0300 Moshe Shemesh wrote:
> >>> In that sense I don't like --live because it doesn't really say much.
> >>> AFAIU it means 1) no link flap; 2) < 2 sec datapath downtime; 3) no
> >>> configuration is lost in kernel or device (including netdev config,
> >>> link config, flow rules, counters etc.). I was hoping at least the
> >>> documentation in patch 14 would be more precise.
> >> Actually, while writing "no-reset" or "live-patching" I meant also no
> >> downtime at all and nothing resets (config, rules ... anything), that
> >> fits mlx5 live-patching.
> >>
> >> However, to make it more generic, I can allow few seconds downtime and
> >> add similar constrains as you mentioned here to "no-reset". I will add
> >> that to the documentation patch.
> > Oh! If your device supports no downtime and packet loss at all that's
> > great. You don't have to weaken the definition now, whoever needs a
> > weaker definition can add a different constraint level later, no?
>
>
> Yes, but if we are thinking there will be more levels, maybe the flag
> "--live" or "--no_reset" is less extendable, we may need new attr. I
> mean should I have uAPI command line like:
>
> $ devlink dev reload DEV [ netns { PID | NAME | ID } ] [ action {
> driver_reinit | fw_activate } [ limit_level no_reset ] ]
>
This sounds good. As coming to our device, user can issue

$devlink dev reload DEV action fw_activate

which resets both firmware and driver entities to activate the new
firmware (either pending flashed firmware or reset current firmware).

Thanks for the patch series.

2020-09-10 06:53:21

by Jiri Pirko

[permalink] [raw]
Subject: Re: [PATCH net-next RFC v3 01/14] devlink: Add reload action option to devlink reload command

Wed, Sep 09, 2020 at 03:27:19PM CEST, [email protected] wrote:
>
>On 9/7/2020 8:58 PM, Jakub Kicinski wrote:
>> On Mon, 7 Sep 2020 16:46:01 +0300 Moshe Shemesh wrote:
>> > > In that sense I don't like --live because it doesn't really say much.
>> > > AFAIU it means 1) no link flap; 2) < 2 sec datapath downtime; 3) no
>> > > configuration is lost in kernel or device (including netdev config,
>> > > link config, flow rules, counters etc.). I was hoping at least the
>> > > documentation in patch 14 would be more precise.
>> > Actually, while writing "no-reset" or "live-patching" I meant also no
>> > downtime at all and nothing resets (config, rules ... anything), that
>> > fits mlx5 live-patching.
>> >
>> > However, to make it more generic, I can allow few seconds downtime and
>> > add similar constrains as you mentioned here to "no-reset". I will add
>> > that to the documentation patch.
>> Oh! If your device supports no downtime and packet loss at all that's
>> great. You don't have to weaken the definition now, whoever needs a
>> weaker definition can add a different constraint level later, no?
>
>
>Yes, but if we are thinking there will be more levels, maybe the flag
>"--live" or "--no_reset" is less extendable, we may need new attr. I mean
>should I have uAPI command line like:
>
>$ devlink dev reload DEV [ netns { PID | NAME | ID } ] [ action {
>driver_reinit | fw_activate } [ limit_level? no_reset ] ]

Sounds fine.

>
>