Re: [PATCH 3/3] drm/xe/pf: Add handling for MLRC adverse event threshold

[Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>]

On 12/12/2025 9:34 AM, Michal Wajdeczko wrote:
> From: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
>
> Since it is illegal to register a MLRC context when scheduler groups are
> enabled, the GuC consider the VF doing so as an adverse event. Like for
> other adverse event, there is a threshold for how many times the event
> can happen before the GuC throws an error, which we need to add support
> for.
>
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>

LGTM. Not sure if my r-b counts as the original author, but here it is 
anyway:

Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>

Daniele

> ---
> v2: split from previous patch, add GuC version checking
> v3: don't move version code to its own file, call MAKE_GUC_VER from the
> caller instead.
> v4: cherry-picked from [1] and rebased (Michal)
>
> [1] https://patchwork.freedesktop.org/series/158142/#rev3
> ---
>   drivers/gpu/drm/xe/abi/guc_klvs_abi.h                | 9 +++++++++
>   drivers/gpu/drm/xe/xe_guc_klv_thresholds_set_types.h | 1 +
>   2 files changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/xe/abi/guc_klvs_abi.h b/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
> index 265a135e7061..89a4f8c504e6 100644
> --- a/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
> +++ b/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
> @@ -352,6 +352,12 @@ enum  {
>    *      :1: NORMAL = schedule VF always, irrespective of whether it has work or not
>    *      :2: HIGH = schedule VF in the next time-slice after current active
>    *          time-slice completes if it has active work
> + *
> + * _`GUC_KLV_VF_CFG_THRESHOLD_MULTI_LRC_COUNT` : 0x8A0D
> + *      Given that multi-LRC contexts are incompatible with SRIOV scheduler
> + *      groups and cause the latter to be turned off when registered with the
> + *      GuC, this config allows the PF to set a threshold for multi-LRC context
> + *      registrations by VFs to monitor their behavior.
>    */
>   
>   #define GUC_KLV_VF_CFG_GGTT_START_KEY		0x0001
> @@ -410,6 +416,9 @@ enum  {
>   #define   GUC_SCHED_PRIORITY_NORMAL		1u
>   #define   GUC_SCHED_PRIORITY_HIGH		2u
>   
> +#define GUC_KLV_VF_CFG_THRESHOLD_MULTI_LRC_COUNT_KEY	0x8a0d
> +#define GUC_KLV_VF_CFG_THRESHOLD_MULTI_LRC_COUNT_LEN	1u
> +
>   /*
>    * Workaround keys:
>    */
> diff --git a/drivers/gpu/drm/xe/xe_guc_klv_thresholds_set_types.h b/drivers/gpu/drm/xe/xe_guc_klv_thresholds_set_types.h
> index 5f84da3d10d3..45ab5a3b5218 100644
> --- a/drivers/gpu/drm/xe/xe_guc_klv_thresholds_set_types.h
> +++ b/drivers/gpu/drm/xe/xe_guc_klv_thresholds_set_types.h
> @@ -37,6 +37,7 @@
>   	define(H2G_STORM, guc_time_us)			\
>   	define(IRQ_STORM, irq_time_us)			\
>   	define(DOORBELL_STORM, doorbell_time_us)	\
> +	define(MULTI_LRC_COUNT, multi_lrc_count, 70, 53)\
>   	/* end */
>   
>   /**