Re: [PATCH net-next RFC v4 01/15] devlink: Add reload action option to devlink reload command

Jiri Pirko
2020-09-14T17:23:02Z

Mon, Sep 14, 2020 at 08:07:48AM CEST, moshe@mellanox.com 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 performed.
>Reload actions supported are:
>driver_reinit: driver entities re-initialization, applying devlink-param
> and devlink-resource values.
>fw_activate: firmware activate.
>
>command examples:
>$devlink dev reload pci/0000:82:00.0 action driver_reinit
>reload_actions_performed:
> driver_reinit
>
>$devlink dev reload pci/0000:82:00.0 action fw_activate
>reload_actions_performed:
> driver_reinit fw_activate
>
>Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
>---
>v3 -> v4:
>- Removed fw_activate_no_reset as an action (next patch adds limit
> levels instead).
>- Renamed actions_done to actions_performed
>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 | 25 ++--
> drivers/net/netdevsim/dev.c | 16 ++-
> include/net/devlink.h | 7 +-
> include/uapi/linux/devlink.h | 19 +++
> net/core/devlink.c | 111 +++++++++++++++++-
> 7 files changed, 180 insertions(+), 27 deletions(-)
>
>diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
>index 70cf24ba71e4..aadf1676a0ed 100644
>--- a/drivers/net/ethernet/mellanox/mlx4/main.c
>+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
>@@ -3946,6 +3946,7 @@ 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);
>@@ -3962,8 +3963,8 @@ 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_performed)
> {
> struct mlx4_priv *priv = devlink_priv(devlink);
> struct mlx4_dev *dev = &priv->dev;
>@@ -3971,15 +3972,20 @@ 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_performed)

Nit, pass the unsigned long allways (even when it would be unused) and
avoid check in every driver.

>+ *actions_performed = 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,
> };

[..]

>@@ -2969,29 +2975,72 @@ 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_performed)
> {
> 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_performed);

Here, please add a WARN_ON() check:
WARN_ON(!(*actions_performed & action));

The requested action should be always performed.

> devlink_reload_failed_set(devlink, !!err);
> return err;
> }
>
>+static int
>+devlink_nl_reload_actions_performed_fill(struct sk_buff *msg,
>+ struct devlink *devlink,
>+ unsigned long actions_performed,
>+ enum devlink_command cmd, u32 portid,
>+ u32 seq, int flags)
>+{
>+ struct nlattr *actions_performed_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_performed_attr = nla_nest_start(msg, DEVLINK_ATTR_RELOAD_ACTIONS_PERFORMED);
>+ if (!actions_performed_attr)
>+ goto genlmsg_cancel;
>+
>+ for (i = 0; i <= DEVLINK_RELOAD_ACTION_MAX; i++) {
>+ if (!test_bit(i, &actions_performed))
>+ continue;
>+ if (nla_put_u8(msg, DEVLINK_ATTR_RELOAD_ACTION, i))
>+ goto actions_performed_nest_cancel;
>+ }
>+ nla_nest_end(msg, actions_performed_attr);
>+ genlmsg_end(msg, hdr);
>+ return 0;
>+
>+actions_performed_nest_cancel:
>+ nla_nest_cancel(msg, actions_performed_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;
>+ unsigned long actions_performed;
> struct net *dest_net = NULL;
>+ struct sk_buff *msg;
> int err;
>
> if (!devlink_reload_supported(devlink))
>@@ -3011,12 +3060,41 @@ 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");

Hmm, I understand the unspec check, but the max check is not needed. The
following check will take care of it.

>+ return -EINVAL;
>+ } else if (!devlink_reload_action_is_supported(devlink, action)) {
>+ NL_SET_ERR_MSG_MOD(info->extack, "Requested reload action is not supported");

".. by the driver" ?

>+ return -EOPNOTSUPP;
>+ }
>+
>+ err = devlink_reload(devlink, dest_net, action, info->extack, &actions_performed);
>
> if (dest_net)
> put_net(dest_net);
>
>- return err;
>+ if (err)
>+ return err;
>+
>+ WARN_ON(!actions_performed);
>+ msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
>+ if (!msg)
>+ return -ENOMEM;
>+
>+ err = devlink_nl_reload_actions_performed_fill(msg, devlink, actions_performed,
>+ 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,
>@@ -7047,6 +7125,7 @@ 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[] = {
>@@ -7372,6 +7451,20 @@ 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))

If reload is not supported, the supported_reload_actions should be 0.
Please check that with WARN_ON too.

>+ 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
> *
>@@ -7392,6 +7485,11 @@ 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)) {

Move this check to the beginning. You don't need devlink instance for
the check, just ops.

also, your devlink_reload_actions_verify() function returns
0/-ESOMETHING. Treat it accordingly here.

>+ 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);
>@@ -9657,7 +9755,8 @@ 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
>