On Mon, 29 Sep 2025 17:44:13 -0400 Rodrigo Vivi wrote:
> Introduces the DRM RAS infrastructure over generic netlink.
Can't comment on the merits but in terms of netlink..
> + ./tools/net/ynl/pyynl/cli.py --spec
> Documentation/netlink/specs/drm_ras.yaml --dump list-nodes
We recommend using the "installed" syntax in examples, so:
ynl --family drm_ras
instead of:
./tools/net/ynl/pyynl/cli.py --spec
Documentation/netlink/specs/drm_ras.yaml
If you're using Fedora or another good distro ynl CLI is packaged (for
Fedora in kernel-tools). The in-tree syntax is a bit verbose.
> + xa_for_each(&drm_ras_xa, id, node) {
> + if (id < ctx->restart)
> + continue;
IIRC xa_for_each_start can make this simpler?
> + hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
> + cb->nlh->nlmsg_seq,
> + &drm_ras_nl_family, NLM_F_MULTI,
> + DRM_RAS_CMD_LIST_NODES);
genlmsg_iput()
genl_info_dump(cb) to get info
> + if (!hdr) {
> + ret = -EMSGSIZE;
> + break;
> + }
> +
> + ret = nla_put_u32(skb, DRM_RAS_A_NODE_ATTRS_NODE_ID, node->id);
> + if (ret) {
> + genlmsg_cancel(skb, hdr);
> + break;
> + }
> +
> + ret = nla_put_string(skb, DRM_RAS_A_NODE_ATTRS_DEVICE_NAME,
> + node->device_name);
> + if (ret) {
> + genlmsg_cancel(skb, hdr);
> + break;
> + }
> +
> + ret = nla_put_string(skb, DRM_RAS_A_NODE_ATTRS_NODE_NAME,
> + node->node_name);
> + if (ret) {
> + genlmsg_cancel(skb, hdr);
> + break;
> + }
> +
> + ret = nla_put_u32(skb, DRM_RAS_A_NODE_ATTRS_NODE_TYPE,
> + node->type);
> + if (ret) {
> + genlmsg_cancel(skb, hdr);
> + break;
> + }
> +
> + genlmsg_end(skb, hdr);
> + }
> +
> + if (ret == -EMSGSIZE) {
> + ctx->restart = id;
> + return skb->len;
> + }
> +
> + return ret;
Separate handling of -EMSGSIZE and returning skb->len is not necessary
as of a few releases ago. Just return ret; core will do the right thing
if ret == -EMSGSIZE and skb->len != 0
> +static int doit_reply_value(struct genl_info *info, u32 node_id,
> + u32 error_id)
> +{
> + struct sk_buff *msg;
> + struct nlattr *hdr;
> + const char *error_name;
> + u32 value;
> + int ret;
> +
> + msg = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> + hdr = genlmsg_put_reply(msg, info, &drm_ras_nl_family, 0,
> + DRM_RAS_CMD_QUERY_ERROR_COUNTER);
> + if (!hdr) {
> + nlmsg_free(msg);
> + return -EMSGSIZE;
> + }
> +
> + ret = get_node_error_counter(node_id, error_id,
> + &error_name, &value);
> + if (ret)
> + return ret;
> +
> + ret = msg_reply_value(msg, error_id, error_name, value);
> + if (ret)
> + return ret;
Leaking message on errors?
> + genlmsg_end(msg, hdr);
> +
> + return genlmsg_reply(msg, info);
> +}
