Re: [PATCH v3 03/10] lib/igt_drm_netlink: Introduce DRM RAS Netlink interface library

[Jani Nikula <jani.nikula@intel.com>]

On Mon, 24 Aug 2026, Ravi Kishore Koppuravuri <ravi.kishore.koppuravuri@intel.com> wrote:
> Introduce an IGT library for communicating with DRM RAS Generic Netlink
> interface. Add helpers for Generic Netlink socket initialization and
> cleanup.
>
> Signed-off-by: Ravi Kishore Koppuravuri <ravi.kishore.koppuravuri@intel.com>
> ---
>  lib/igt_drm_netlink.c | 60 +++++++++++++++++++++++++++++++++++++++++++
>  lib/igt_drm_netlink.h | 25 ++++++++++++++++++
>  lib/meson.build       |  1 +
>  3 files changed, 86 insertions(+)
>  create mode 100644 lib/igt_drm_netlink.c
>  create mode 100644 lib/igt_drm_netlink.h
>
> diff --git a/lib/igt_drm_netlink.c b/lib/igt_drm_netlink.c
> new file mode 100644
> index 000000000..fec1639b4
> --- /dev/null
> +++ b/lib/igt_drm_netlink.c
> @@ -0,0 +1,60 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2026 Intel Corporation
> + */
> +
> +#include <stdbool.h>
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +
> +#include <netlink/errno.h>
> +#include <netlink/genl/ctrl.h>
> +#include <netlink/genl/genl.h>
> +#include <netlink/netlink.h>
> +
> +#include "igt_core.h"
> +#include "igt_drm_netlink.h"
> +
> +void igt_cleanup_nl_socket(struct app_context *ctx)
> +{
> +	if (!ctx || !ctx->sock)
> +		return;
> +
> +	nl_close(ctx->sock);
> +	nl_socket_free(ctx->sock);
> +	ctx->sock = NULL;
> +	ctx->family_id = -1;
> +
> +	igt_debug("Cleaned up netlink socket.\n");
> +}
> +
> +int igt_init_nl_socket(struct app_context *ctx)
> +{
> +	ctx->sock = nl_socket_alloc();
> +	if (!ctx->sock)
> +		return -1;
> +
> +	igt_debug("Socket allocation successful. Connecting to Generic Netlink...\n");
> +	if (genl_connect(ctx->sock) < 0) {
> +		igt_cleanup_nl_socket(ctx);
> +		return -1;
> +	}
> +
> +	igt_debug("Resolving Generic Netlink family '%s'...\n", DRM_RAS_FAMILY_NAME);
> +	ctx->family_id = genl_ctrl_resolve(ctx->sock, DRM_RAS_FAMILY_NAME);
> +	if (ctx->family_id < 0) {
> +		fprintf(stderr,
> +			"Failed to resolve Generic Netlink family '%s': %s. "
> +			"This may mean the running kernel does not expose DRM RAS support.\n",
> +			DRM_RAS_FAMILY_NAME,
> +			nl_geterror(ctx->family_id));
> +		igt_cleanup_nl_socket(ctx);
> +		return -1;
> +	}
> +
> +	igt_debug("Resolved Generic Netlink family '%s' with id %d.\n",
> +		  DRM_RAS_FAMILY_NAME, ctx->family_id);
> +	return 0;
> +}
> diff --git a/lib/igt_drm_netlink.h b/lib/igt_drm_netlink.h
> new file mode 100644
> index 000000000..f681a3a81
> --- /dev/null
> +++ b/lib/igt_drm_netlink.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2026 Intel Corporation
> + */
> +
> +#ifndef IGT_DRM_NETLINK_H
> +#define IGT_DRM_NETLINK_H
> +
> +#include <stdbool.h>

There are no bools here?

> +#include <stdint.h>

There are no stdints here?

> +
> +#include <netlink/netlink.h>

You could get away with a forward declaration.

> +
> +#include <drm-uapi/drm_ras.h>

You're not using that here.

> +
> +struct app_context {

Why doesn't the name indicate netlink in any way?

> +	struct nl_sock *sock;
> +	int family_id;
> +};
> +
> +void igt_cleanup_nl_socket(struct app_context *ctx);
> +int igt_init_nl_socket(struct app_context *ctx);

IMO "nl" is the wrong place to abbreviate.

> +
> +#endif /* IGT_DRM_NETLINK_H */
> +
> diff --git a/lib/meson.build b/lib/meson.build
> index 7248bbc2d..70da9a4a0 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -27,6 +27,7 @@ lib_sources = [
>  	'igt_device_scan.c',
>  	'igt_drm_clients.h',
>  	'igt_drm_fdinfo.c',
> +	'igt_drm_netlink.c',
>          'igt_fs.c',
>  	'igt_aux.c',
>  	'igt_dp.c',

-- 
Jani Nikula, Intel