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

Moshe Shemesh
2020-09-15T12:18:24Z

On 9/14/2020 3:27 PM, Jiri Pirko wrote:
> 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.
>

Ack.

>> + *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.
>
Good point, I will add.
>> 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.
>
Ack.
>> + 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" ?
>

Yes, will fix.

>> + 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.
>
OK, same goes to supported limit levels.
>> + 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.

Right, will fix.

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

Well, yes, but I rather return NULL here since devlink_alloc() failed.
If devlink_reload_actions_verify() fails it has WARN_ON which will lead
the driver developer to his bug.

>
>> + 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
>>