Re: [PATCH 07/10] drm/xe/sriov: Prep for multiple exec quantums and preemption timeouts

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

On 11/27/2025 2:45 AM, Daniele Ceraolo Spurio wrote:
> Each scheduler group can be independently configured with its own exec
> quantum and preemption timeouts. The existing KLVs to configure those
> parameter will apply the value to all groups (even if they're not

typo: parameters

> enabled at the moment).
> 
> When scheduler groups are disable the GuC used the values from Group 0.

typo: ... disabled then GuC uses ... ?

> 
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
> ---
>  drivers/gpu/drm/xe/abi/guc_klvs_abi.h         |  7 ++++--
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c    | 25 +++++++++++++------
>  .../gpu/drm/xe/xe_gt_sriov_pf_config_types.h  |  5 ++--
>  3 files changed, 25 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/abi/guc_klvs_abi.h b/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
> index a6dce9da339f..48f47e26132d 100644
> --- a/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
> +++ b/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
> @@ -290,7 +290,9 @@ enum  {
>   *      infinitely long compute or shader kernel. In such a scenario, the
>   *      PF would need to trigger a VM PAUSE and then change the KLV to force
>   *      it to take effect. Such cases might typically happen on a 1PF+1VF
> - *      Virtualization config enabled for heavier workloads like AI/ML.
> + *      Virtualization config enabled for heavier workloads like AI/ML. If

start with new empty line so it will rendered as separate paragraph

> + *      scheduling groups are supported, the provided value is applied to all
> + *      groups (even if they've not yet been enabled).

should we document also here that "The scheduling groups are available starting from GuC 70.53" ?

>   *
>   *      The max value for this KLV is 100 seconds, anything exceeding that
>   *      will be clamped to the max.
> @@ -312,7 +314,8 @@ enum  {
>   *      In this case, the PF would need to trigger a VM PAUSE and then change
>   *      the KLV to force it to take effect. Such cases might typically happen
>   *      on a 1PF+1VF Virtualization config enabled for heavier workloads like
> - *      AI/ML.
> + *      AI/ML. If scheduling groups are supported, the provided value is applied
> + *      to all groups (even if they've not yet been enabled).

ditto

>   *
>   *      The max value for this KLV is 100 seconds, anything exceeding that
>   *      will be clamped to the max.
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> index 59c5c6b4d994..eb547fedb6da 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> @@ -298,10 +298,10 @@ static u32 encode_config(u32 *cfg, const struct xe_gt_sriov_config *config, bool
>  	}
>  
>  	cfg[n++] = PREP_GUC_KLV_TAG(VF_CFG_EXEC_QUANTUM);
> -	cfg[n++] = config->exec_quantum;
> +	cfg[n++] = config->exec_quantum[0];
>  
>  	cfg[n++] = PREP_GUC_KLV_TAG(VF_CFG_PREEMPT_TIMEOUT);
> -	cfg[n++] = config->preempt_timeout;
> +	cfg[n++] = config->preempt_timeout[0];
>  
>  #define encode_threshold_config(TAG, ...) ({					\
>  	cfg[n++] = PREP_GUC_KLV_TAG(VF_CFG_THRESHOLD_##TAG);			\
> @@ -1857,12 +1857,15 @@ static int pf_provision_exec_quantum(struct xe_gt *gt, unsigned int vfid,
>  {
>  	struct xe_gt_sriov_config *config = pf_pick_vf_config(gt, vfid);
>  	int err;
> +	int i;
>  
>  	err = pf_push_vf_cfg_exec_quantum(gt, vfid, &exec_quantum);
>  	if (unlikely(err))
>  		return err;
>  
> -	config->exec_quantum = exec_quantum;
> +	for (i = 0; i < GUC_KLV_VGT_POLICY_ENGINE_GROUP_MAX_COUNT; i++)

maybe:

	for (i = 0; i < ARRAY_SIZE(config->exec_quantum); i++)

> +		config->exec_quantum[i] = exec_quantum;
> +
>  	return 0;
>  }
>  
> @@ -1870,7 +1873,7 @@ static u32 pf_get_exec_quantum(struct xe_gt *gt, unsigned int vfid)
>  {
>  	struct xe_gt_sriov_config *config = pf_pick_vf_config(gt, vfid);
>  
> -	return config->exec_quantum;
> +	return config->exec_quantum[0];
>  }
>  
>  /**
> @@ -1987,12 +1990,14 @@ static int pf_provision_preempt_timeout(struct xe_gt *gt, unsigned int vfid,
>  {
>  	struct xe_gt_sriov_config *config = pf_pick_vf_config(gt, vfid);
>  	int err;
> +	int i;
>  
>  	err = pf_push_vf_cfg_preempt_timeout(gt, vfid, &preempt_timeout);
>  	if (unlikely(err))
>  		return err;
>  
> -	config->preempt_timeout = preempt_timeout;
> +	for (i = 0; i < GUC_KLV_VGT_POLICY_ENGINE_GROUP_MAX_COUNT; i++)

ditto

> +		config->preempt_timeout[i] = preempt_timeout;
>  
>  	return 0;
>  }
> @@ -2001,7 +2006,7 @@ static u32 pf_get_preempt_timeout(struct xe_gt *gt, unsigned int vfid)
>  {
>  	struct xe_gt_sriov_config *config = pf_pick_vf_config(gt, vfid);
>  
> -	return config->preempt_timeout;
> +	return config->preempt_timeout[0];
>  }
>  
>  /**
> @@ -2180,10 +2185,14 @@ u32 xe_gt_sriov_pf_config_get_sched_priority(struct xe_gt *gt, unsigned int vfid
>  
>  static void pf_reset_config_sched(struct xe_gt *gt, struct xe_gt_sriov_config *config)
>  {
> +	int i;
> +
>  	lockdep_assert_held(xe_gt_sriov_pf_master_mutex(gt));
>  
> -	config->exec_quantum = 0;
> -	config->preempt_timeout = 0;
> +	for (i = 0; i < GUC_KLV_VGT_POLICY_ENGINE_GROUP_MAX_COUNT; i++) {
> +		config->exec_quantum[i] = 0;
> +		config->preempt_timeout[i] = 0;
> +	}
>  }
>  
>  static int pf_provision_threshold(struct xe_gt *gt, unsigned int vfid,
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config_types.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config_types.h
> index 686c7b3b6d7a..abf003946242 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config_types.h
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config_types.h
> @@ -6,6 +6,7 @@
>  #ifndef _XE_GT_SRIOV_PF_CONFIG_TYPES_H_
>  #define _XE_GT_SRIOV_PF_CONFIG_TYPES_H_
>  
> +#include "abi/guc_klvs_abi.h"
>  #include "xe_ggtt_types.h"
>  #include "xe_guc_klv_thresholds_set_types.h"
>  
> @@ -30,9 +31,9 @@ struct xe_gt_sriov_config {
>  	/** @begin_db: start index of GuC doorbell ID range. */
>  	u16 begin_db;
>  	/** @exec_quantum: execution-quantum in milliseconds. */
> -	u32 exec_quantum;
> +	u32 exec_quantum[GUC_KLV_VGT_POLICY_ENGINE_GROUP_MAX_COUNT];
>  	/** @preempt_timeout: preemption timeout in microseconds. */
> -	u32 preempt_timeout;
> +	u32 preempt_timeout[GUC_KLV_VGT_POLICY_ENGINE_GROUP_MAX_COUNT];

maybe we should rename

	GUC_KLV_VGT_POLICY_ENGINE_GROUP_MAX_COUNT
to
	GUC_MAX_ENGINE_GROUPS

and make it independent from KLVs and define like we have

	GUC_MAX_ENGINE_CLASSES


>  	/** @sched_priority: scheduling priority. */
>  	u32 sched_priority;
>  	/** @thresholds: GuC thresholds for adverse events notifications. */