Re: [PATCH v2 05/11] drm/xe/sriov: Add handling for MLRC adverse event threshold

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

On 12/7/2025 12:04 AM, Daniele Ceraolo Spurio wrote:
> 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.
> 
> Since this is the first threshold that we have that has a minimum GuC
> version requirement, support for checking that has been added to the
> generic threshold handling. As part of it, some of the version code has
> been moved to its own file and with the occasion some SRIOV
> documentation has been added.
> 
> v2: split from previous patch, add GuC version checking
> 
> 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         |  9 +++++
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c    | 19 ++++++----
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c   |  9 +++--
>  drivers/gpu/drm/xe/xe_guc.h                   |  7 +---
>  .../drm/xe/xe_guc_klv_thresholds_set_types.h  | 18 +++++-----
>  drivers/gpu/drm/xe/xe_guc_version.h           | 36 +++++++++++++++++++
>  6 files changed, 74 insertions(+), 24 deletions(-)
>  create mode 100644 drivers/gpu/drm/xe/xe_guc_version.h
> 
> diff --git a/drivers/gpu/drm/xe/abi/guc_klvs_abi.h b/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
> index edb0546fb163..30a051a0b4ee 100644
> --- a/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
> +++ b/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
> @@ -376,6 +376,12 @@ 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
> @@ -434,6 +440,9 @@ 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_gt_sriov_pf_config.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> index 59c5c6b4d994..dda671d05b89 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
> @@ -269,7 +269,8 @@ static u32 encode_config_ggtt(u32 *cfg, const struct xe_gt_sriov_config *config,
>  }
>  
>  /* Return: number of configuration dwords written */
> -static u32 encode_config(u32 *cfg, const struct xe_gt_sriov_config *config, bool details)
> +static u32 encode_config(struct xe_gt *gt, u32 *cfg,
> +			 const struct xe_gt_sriov_config *config, bool details)
>  {
>  	u32 n = 0;
>  
> @@ -303,9 +304,11 @@ static u32 encode_config(u32 *cfg, const struct xe_gt_sriov_config *config, bool
>  	cfg[n++] = PREP_GUC_KLV_TAG(VF_CFG_PREEMPT_TIMEOUT);
>  	cfg[n++] = config->preempt_timeout;
>  
> -#define encode_threshold_config(TAG, ...) ({					\
> -	cfg[n++] = PREP_GUC_KLV_TAG(VF_CFG_THRESHOLD_##TAG);			\
> -	cfg[n++] = config->thresholds[MAKE_XE_GUC_KLV_THRESHOLD_INDEX(TAG)];	\
> +#define encode_threshold_config(TAG, NAME, MIN_GUC_VER) ({				\
> +	if (!MIN_GUC_VER || GUC_FIRMWARE_VER(&gt->uc.guc) >= MIN_GUC_VER) {		\
> +		cfg[n++] = PREP_GUC_KLV_TAG(VF_CFG_THRESHOLD_##TAG);			\
> +		cfg[n++] = config->thresholds[MAKE_XE_GUC_KLV_THRESHOLD_INDEX(TAG)];	\
> +	}										\
>  });
>  
>  	MAKE_XE_GUC_KLV_THRESHOLDS_SET(encode_threshold_config);
> @@ -328,7 +331,7 @@ static int pf_push_full_vf_config(struct xe_gt *gt, unsigned int vfid)
>  		return -ENOBUFS;
>  
>  	cfg = xe_guc_buf_cpu_ptr(buf);
> -	num_dwords = encode_config(cfg, config, true);
> +	num_dwords = encode_config(gt, cfg, config, true);
>  	xe_gt_assert(gt, num_dwords <= max_cfg_dwords);
>  
>  	if (xe_gt_is_media_type(gt)) {
> @@ -2518,7 +2521,7 @@ ssize_t xe_gt_sriov_pf_config_save(struct xe_gt *gt, unsigned int vfid, void *bu
>  			ret = -ENOBUFS;
>  		} else {
>  			config = pf_pick_vf_config(gt, vfid);
> -			ret = encode_config(buf, config, false) * sizeof(u32);
> +			ret = encode_config(gt, buf, config, false) * sizeof(u32);
>  		}
>  	}
>  	mutex_unlock(xe_gt_sriov_pf_master_mutex(gt));
> @@ -2551,9 +2554,11 @@ static int pf_restore_vf_config_klv(struct xe_gt *gt, unsigned int vfid,
>  		return pf_provision_preempt_timeout(gt, vfid, value[0]);
>  
>  	/* auto-generate case statements */
> -#define define_threshold_key_to_provision_case(TAG, ...)				\
> +#define define_threshold_key_to_provision_case(TAG, NAME, MIN_GUC_VER)			\
>  	case MAKE_GUC_KLV_VF_CFG_THRESHOLD_KEY(TAG):					\
>  		BUILD_BUG_ON(MAKE_GUC_KLV_VF_CFG_THRESHOLD_LEN(TAG) != 1u);		\
> +		if (MIN_GUC_VER && GUC_FIRMWARE_VER(&gt->uc.guc) < MIN_GUC_VER)		\
> +			return -ENOKEY;							\
>  		if (len != MAKE_GUC_KLV_VF_CFG_THRESHOLD_LEN(TAG))			\
>  			return -EBADMSG;						\
>  		return pf_provision_threshold(gt, vfid,					\
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
> index 0fd863609848..5123ff1fb116 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
> @@ -21,6 +21,7 @@
>  #include "xe_gt_sriov_pf_monitor.h"
>  #include "xe_gt_sriov_pf_policy.h"
>  #include "xe_gt_sriov_pf_service.h"
> +#include "xe_guc.h"
>  #include "xe_pm.h"
>  #include "xe_sriov_pf.h"
>  #include "xe_sriov_pf_provision.h"
> @@ -301,9 +302,11 @@ static void pf_add_config_attrs(struct xe_gt *gt, struct dentry *parent, unsigne
>  				   &sched_priority_fops);
>  
>  	/* register all threshold attributes */
> -#define register_threshold_attribute(TAG, NAME, ...) \
> -	debugfs_create_file_unsafe("threshold_" #NAME, 0644, parent, parent, \
> -				   &NAME##_fops);
> +#define register_threshold_attribute(TAG, NAME, MIN_GUC_VER) ({				\
> +	if (!MIN_GUC_VER || GUC_FIRMWARE_VER(&gt->uc.guc) >= MIN_GUC_VER)		\
> +		debugfs_create_file_unsafe("threshold_" #NAME, 0644, parent, parent,	\
> +					   &NAME##_fops);				\
> +});
>  	MAKE_XE_GUC_KLV_THRESHOLDS_SET(register_threshold_attribute)
>  #undef register_threshold_attribute
>  }
> diff --git a/drivers/gpu/drm/xe/xe_guc.h b/drivers/gpu/drm/xe/xe_guc.h
> index fdb08658d05a..9028718189ed 100644
> --- a/drivers/gpu/drm/xe/xe_guc.h
> +++ b/drivers/gpu/drm/xe/xe_guc.h
> @@ -8,15 +8,10 @@
>  
>  #include "xe_gt.h"
>  #include "xe_guc_types.h"
> +#include "xe_guc_version.h"
>  #include "xe_hw_engine_types.h"
>  #include "xe_macros.h"
>  
> -/*
> - * GuC version number components are defined to be only 8-bit size,
> - * so converting to a 32bit 8.8.8 integer allows simple (and safe)
> - * numerical comparisons.
> - */
> -#define MAKE_GUC_VER(maj, min, pat)	(((maj) << 16) | ((min) << 8) | (pat))
>  #define MAKE_GUC_VER_STRUCT(ver)	MAKE_GUC_VER((ver).major, (ver).minor, (ver).patch)

I guess this macro can also be moved

>  #define GUC_SUBMIT_VER(guc) \
>  	MAKE_GUC_VER_STRUCT((guc)->fw.versions.found[XE_UC_FW_VER_COMPATIBILITY])
> 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 0a028c94756d..f7ed32244c6b 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
> @@ -7,6 +7,7 @@
>  #define _XE_GUC_KLV_THRESHOLDS_SET_TYPES_H_
>  
>  #include "xe_args.h"
> +#include "xe_guc_version.h"
>  
>  /**
>   * MAKE_XE_GUC_KLV_THRESHOLDS_SET - Generate various GuC thresholds definitions.
> @@ -23,15 +24,16 @@
>   * with the &TAG, that corresponds to the GuC threshold KLV key name defined by
>   * ABI and the associated &NAME, that may be used in code or debugfs/sysfs::
>   *
> - *	define(TAG, NAME)
> + *	define(TAG, NAME, MIN_GUC_VER)
>   */
> -#define MAKE_XE_GUC_KLV_THRESHOLDS_SET(define)		\
> -	define(CAT_ERR, cat_error_count)		\
> -	define(ENGINE_RESET, engine_reset_count)	\
> -	define(PAGE_FAULT, page_fault_count)		\
> -	define(H2G_STORM, guc_time_us)			\
> -	define(IRQ_STORM, irq_time_us)			\
> -	define(DOORBELL_STORM, doorbell_time_us)	\
> +#define MAKE_XE_GUC_KLV_THRESHOLDS_SET(define)					\
> +	define(CAT_ERR, cat_error_count, 0)					\
> +	define(ENGINE_RESET, engine_reset_count, 0)				\
> +	define(PAGE_FAULT, page_fault_count, 0)					\
> +	define(H2G_STORM, guc_time_us, 0)					\
> +	define(IRQ_STORM, irq_time_us, 0)					\
> +	define(DOORBELL_STORM, doorbell_time_us, 0)				\
> +	define(MULTI_LRC_COUNT, multi_lrc_count, MAKE_GUC_VER(70, 53, 0))	\
>  	/* end */
>  
>  /**
> diff --git a/drivers/gpu/drm/xe/xe_guc_version.h b/drivers/gpu/drm/xe/xe_guc_version.h
> new file mode 100644

introduction of this new ver.h file is self-contained so maybe it should be in its own patch?

> index 000000000000..e6f80abd2f05
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_guc_version.h
> @@ -0,0 +1,36 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#ifndef _XE_GUC_VERSION_H_
> +#define _XE_GUC_VERSION_H_
> +
> +/*

this should be regular kernel-doc

> + * GuC version number components are defined to be only 8-bit size,
> + * so converting to a 32bit 8.8.8 integer allows simple (and safe)
> + * numerical comparisons.
> + */
> +#define MAKE_GUC_VER(maj, min, pat)	(((maj) << 16) | ((min) << 8) | (pat))
> +
> +/**
> + * DOC: SRIOV-changes

	DOC: SR-IOV Changes

> + *
> + * We record SRIOV-specific changes here as those need to be tracked carefully.
> + *

what about 1.23.0 (CCS) ?

> + * GuC 70.53.0 (VF interface 1.26.0):
> + *
> + * Added support for EGS. See:

probably we need extra line here to render correctly

> + *  * GUC_KLV_VGT_POLICY_ENGINE_GROUP_CONFIG
> + *  * GUC_KLV_VF_CFG_THRESHOLD_MULTI_LRC_COUNT
> + *
> + * GuC 70.54.0 (VF interface 1.27.0):
> + *
> + * Updated VF migration support. See RESFIX actions

maybe we can list those actions:

	* VF2GUC_RESFIX_START
	* VF2GUC_RESFIX_DONE

> + *
> + * GuC 70.55.1 (VF interface 1.28.1):
> + *
> + * Fixes for EGS.
> + */
> +
> +#endif