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 12:15 PM, Daniele Ceraolo Spurio wrote:
>
>
> 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>

BTW, this patch is different enough from previous revs that you should 
probably take authorship of it.

Daniele

>
> 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 */
>>     /**
>