Re: [PATCH] drm/xe/guc: Ratelimit diagnostic messages from the relay

["Piotr Piórkowski" <piotr.piorkowski@intel.com>]

Michal Wajdeczko <michal.wajdeczko@intel.com> wrote on nie [2025-paź-05 19:39:46 +0200]:
> There might be some malicious VFs that by sending an invalid VF2PF
> relay messages will flood PF's dmesg with our diagnostics messages.
> 
> Rate limit all relay messages, unless running in DEBUG_SRIOV mode.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_guc_relay.c       | 17 +++++++++++++++--
>  drivers/gpu/drm/xe/xe_guc_relay_types.h |  4 ++++
>  2 files changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_relay.c b/drivers/gpu/drm/xe/xe_guc_relay.c
> index e5dc94f3e618..0c0ff24ba62a 100644
> --- a/drivers/gpu/drm/xe/xe_guc_relay.c
> +++ b/drivers/gpu/drm/xe/xe_guc_relay.c
> @@ -56,9 +56,19 @@ static struct xe_device *relay_to_xe(struct xe_guc_relay *relay)
>  	return gt_to_xe(relay_to_gt(relay));
>  }
>  
> +#define XE_RELAY_DIAG_RATELIMIT_INTERVAL	(10 * HZ)
> +#define XE_RELAY_DIAG_RATELIMIT_BURST		10
> +
> +#define relay_ratelimit_printk(relay, _level, fmt...) ({			\
> +	typeof(relay) _r = (relay);						\
> +	if (IS_ENABLED(CONFIG_DRM_XE_DEBUG_SRIOV) ||				\
> +	    ___ratelimit(&_r->diag_ratelimit, "xe_guc_relay"))			\
> +		xe_gt_sriov_##_level(relay_to_gt(_r), "relay: " fmt);		\
> +})
> +
>  #define relay_assert(relay, condition)	xe_gt_assert(relay_to_gt(relay), condition)
> -#define relay_notice(relay, msg...)	xe_gt_sriov_notice(relay_to_gt(relay), "relay: " msg)
> -#define relay_debug(relay, msg...)	xe_gt_sriov_dbg_verbose(relay_to_gt(relay), "relay: " msg)
> +#define relay_notice(relay, msg...)	relay_ratelimit_printk((relay), notice, msg)
> +#define relay_debug(relay, msg...)	relay_ratelimit_printk((relay), dbg_verbose, msg)
>  
>  static int relay_get_totalvfs(struct xe_guc_relay *relay)
>  {
> @@ -345,6 +355,9 @@ int xe_guc_relay_init(struct xe_guc_relay *relay)
>  	INIT_WORK(&relay->worker, relays_worker_fn);
>  	INIT_LIST_HEAD(&relay->pending_relays);
>  	INIT_LIST_HEAD(&relay->incoming_actions);
> +	ratelimit_state_init(&relay->diag_ratelimit,
> +			     XE_RELAY_DIAG_RATELIMIT_INTERVAL,
> +			     XE_RELAY_DIAG_RATELIMIT_BURST);
>  
>  	err = mempool_init_kmalloc_pool(&relay->pool, XE_RELAY_MEMPOOL_MIN_NUM +
>  					relay_get_totalvfs(relay),
> diff --git a/drivers/gpu/drm/xe/xe_guc_relay_types.h b/drivers/gpu/drm/xe/xe_guc_relay_types.h
> index 5999fcb77e96..20eee10856b2 100644
> --- a/drivers/gpu/drm/xe/xe_guc_relay_types.h
> +++ b/drivers/gpu/drm/xe/xe_guc_relay_types.h
> @@ -7,6 +7,7 @@
>  #define _XE_GUC_RELAY_TYPES_H_
>  
>  #include <linux/mempool.h>
> +#include <linux/ratelimit_types.h>
>  #include <linux/spinlock.h>
>  #include <linux/workqueue.h>
>  
> @@ -31,6 +32,9 @@ struct xe_guc_relay {
>  
>  	/** @last_rid: last Relay-ID used while sending a message. */
>  	u32 last_rid;
> +
> +	/** @diag_ratelimit: ratelimit state used to throttle diagnostics messages. */
> +	struct ratelimit_state diag_ratelimit;
>  };

LGTM:
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>

>  
>  #endif
> -- 
> 2.47.1
> 

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