From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8559730C371; Mon, 25 May 2026 21:09:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779743393; cv=none; b=oK85V3hxpykg1VCthvTaxHl2kU+sM0o1as0LC15ITwK+wuGKW6VluHL/wNN857I5qvKSNhzI6qXykaHheGRfCF4juyPBk8olOqQ88fTlsG3BFG0600W/KuOP4bGUBxA8DGb9oRwEezbx1O9uelSj9IFcHwxMDnpn7JHXeF1mV48= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779743393; c=relaxed/simple; bh=/xYmC0F1r/G0vhtFk4QqxRRRrD5vvJvYIa4MINZvR/o=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=dqAC/+u6x190ythWlVJ285tHuBp0C8rLhCgffM+P0Bm5BjiaH7LjkoKh3oYH/kSKDs0Niuh2sUYK59pV0cCMHpZ7QMYwOupCqJbg1Mxuqi1N3IHRRz0vYIPyeye5ie1gEL7u8UDcBR/2aDTNXbvKEDqMhen7Jok14gHtJ+hLvjU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TihYrZW8; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TihYrZW8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1AAA91F000E9; Mon, 25 May 2026 21:09:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779743392; bh=18u4KIJFG/FGlDDbOxnHj9dWhrDn5wztIGKAiz2Fya0=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=TihYrZW8bP14POQyR7rxRNh2oCwolKTDzzGEk4yWuemeA19V0T3Igl5LTwR/wxsTw 0AwpFE3cSvtNeMoY7BT6/Vdj9XW6nHgEXC59EMpm92U8GhtEAN15uRNTruBmOD0LxU T5QDgJfTKZ/fint3AVyPwzzDNhpQuZRKjAkPpvtcAlm8ZumIUjq41C/egvnixHfnOe IFgXGb/P3Vu3F1qSqFgUZ2fWVZwQru3/1NLfQxpgxXoKMjCQOad/VecAIdC7YnBaK6 z6Tzr+ZqlraqbT8FGJd+pTnoiwTauW3MJnvtlUhShF8B0Udz0fCY8wXTzlCfpONwYE /TdFkZi1PvGvg== Date: Mon, 25 May 2026 14:09:50 -0700 From: Jakub Kicinski To: Ratheesh Kannoth Cc: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v16 net-next 4/9] devlink: Implement devlink param multi attribute nested data values Message-ID: <20260525140950.7e5cac5e@kernel.org> In-Reply-To: <20260521095303.2395584-5-rkannoth@marvell.com> References: <20260521095303.2395584-1-rkannoth@marvell.com> <20260521095303.2395584-5-rkannoth@marvell.com> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 21 May 2026 15:22:58 +0530 Ratheesh Kannoth wrote: > From: Saeed Mahameed > > 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 u64 values, by introducing a new devlink param type > DEVLINK_PARAM_TYPE_U64_ARRAY, driver and user space can set a variable > count of u64 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. > diff --git a/net/devlink/param.c b/net/devlink/param.c > index 1a196d3a843d..6e0e48696f4a 100644 > --- a/net/devlink/param.c > +++ b/net/devlink/param.c > @@ -252,6 +252,15 @@ devlink_nl_param_value_put(struct sk_buff *msg, enum devlink_param_type type, > return -EMSGSIZE; > } > break; > + case DEVLINK_PARAM_TYPE_U64_ARRAY: > + for (int i = 0; i < val->u64arr.size; i++) { > + if (i >= __DEVLINK_PARAM_MAX_ARRAY_SIZE) > + break; Why not check this before the loop and return an error if someone tries to dump too much data? > + if (nla_put_uint(msg, nla_type, val->u64arr.val[i])) > + return -EMSGSIZE; > + } > + break; > } > return 0; > } > @@ -304,56 +313,78 @@ 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]; > 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; > - struct devlink_param_gset_ctx ctx; > + union devlink_param_value *default_value; > + union devlink_param_value *param_value; > + struct devlink_param_gset_ctx *ctx; > struct nlattr *param_values_list; > struct nlattr *param_attr; > void *hdr; > int err; > int i; > > + default_value = kcalloc(DEVLINK_PARAM_CMODE_MAX + 1, > + sizeof(*default_value), GFP_KERNEL); > + if (!default_value) > + return -ENOMEM; > + > + param_value = kcalloc(DEVLINK_PARAM_CMODE_MAX + 1, > + sizeof(*param_value), GFP_KERNEL); > + if (!param_value) { > + kfree(default_value); > + return -ENOMEM; > + } > + > + ctx = kzalloc_obj(*ctx); > + if (!ctx) { > + kfree(param_value); > + kfree(default_value); > + return -ENOMEM; > + } The mem alloc should preferably be a separate patch for ease of review. > static void devlink_param_notify(struct devlink *devlink, > @@ -507,7 +545,7 @@ 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 +585,26 @@ 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_U64_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; > + > + if ((nla_len(param_data) != sizeof(u64)) && > + (nla_len(param_data) != sizeof(u32))) NL_SET_BAD_ATTR() would be good here > + return -EINVAL; > + > + value->u64arr.val[cnt] = (u64)nla_get_uint(param_data); Why the cast? Looks like a leftover.. > + cnt++; > + } > + > + value->u64arr.size = cnt; > + break; > } > return 0; > }