Re: [PATCH v4 1/2] drm/xe/pagefault: Add SRCID to pagefault struct

[Matthew Brost]

On Thu, Jun 18, 2026 at 11:33:11PM +0800, Jonathan Cavitt wrote:
> Add SRCID information to pagefault struct for the purpose of reporting
> the hardware unit that resulted in the pagefault.
> 
> v2:
> - Squash SRCID with ASID to keep the struct compact (Matthew)
> 
> Signed-off-by: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx>
> Cc: Matthew Brost <matthew.brost@xxxxxxxxx>
> Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxxx>
> Cc: Simona Vetter <simona@xxxxxxxx>
> ---
>  drivers/gpu/drm/xe/xe_guc_pagefault.c   |  5 ++++-
>  drivers/gpu/drm/xe/xe_pagefault.c       | 23 +++++++++++++++--------
>  drivers/gpu/drm/xe/xe_pagefault_types.h |  9 +++++++--
>  3 files changed, 26 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_pagefault.c b/drivers/gpu/drm/xe/xe_guc_pagefault.c
> index 607e32392f46..7d24bd828e5b 100644
> --- a/drivers/gpu/drm/xe/xe_guc_pagefault.c
> +++ b/drivers/gpu/drm/xe/xe_guc_pagefault.c
> @@ -78,7 +78,10 @@ int xe_guc_pagefault_handler(struct xe_guc *guc, u32 *msg, u32 len)
>  				      << PFD_VIRTUAL_ADDR_HI_SHIFT) |
>  		(FIELD_GET(PFD_VIRTUAL_ADDR_LO, msg[2]) <<
>  		 PFD_VIRTUAL_ADDR_LO_SHIFT);
> -	pf.consumer.asid = FIELD_GET(PFD_ASID, msg[1]);

Maybe a BUILD_ON_BUG(XE_MAX_ASID > XE_PAGEFAULT_ASID_MASK);

> +	pf.consumer.id = FIELD_PREP(XE_PAGEFAULT_ASID_MASK,
> +				    FIELD_GET(PFD_ASID, msg[1])) |
> +			 FIELD_PREP(XE_PAGEFAULT_SRCID_MASK,
> +				    FIELD_GET(PFD_SRC_ID, msg[0]));
>  	pf.consumer.access_type = FIELD_GET(PFD_ACCESS_TYPE, msg[2]) |
>  		(FIELD_GET(PFD_PREFETCH, msg[2]) ? XE_PAGEFAULT_ACCESS_PREFETCH : 0);
>  	if (FIELD_GET(XE2_PFD_TRVA_FAULT, msg[0]))
> diff --git a/drivers/gpu/drm/xe/xe_pagefault.c b/drivers/gpu/drm/xe/xe_pagefault.c
> index dd3c068e1a39..2a21203b1a2a 100644
> --- a/drivers/gpu/drm/xe/xe_pagefault.c
> +++ b/drivers/gpu/drm/xe/xe_pagefault.c
> @@ -169,6 +169,7 @@ static struct xe_vm *xe_pagefault_asid_to_vm(struct xe_device *xe, u32 asid)
>  
>  static int xe_pagefault_service(struct xe_pagefault *pf)
>  {
> +	u32 asid = FIELD_GET(XE_PAGEFAULT_ASID_MASK, pf->consumer.id);

Nit: can you move this below the struct stack variables.

>  	struct xe_gt *gt = pf->gt;
>  	struct xe_device *xe = gt_to_xe(gt);
>  	struct xe_vm *vm;
> @@ -180,7 +181,7 @@ static int xe_pagefault_service(struct xe_pagefault *pf)
>  	if (pf->consumer.fault_type_level == XE_PAGEFAULT_TYPE_LEVEL_NACK)
>  		return -EFAULT;
>  
> -	vm = xe_pagefault_asid_to_vm(xe, pf->consumer.asid);
> +	vm = xe_pagefault_asid_to_vm(xe, asid);
>  	if (IS_ERR(vm))
>  		return PTR_ERR(vm);
>  
> @@ -242,14 +243,16 @@ static bool xe_pagefault_queue_pop(struct xe_pagefault_queue *pf_queue,
>  
>  static void xe_pagefault_print(struct xe_pagefault *pf)
>  {
> -	xe_gt_info(pf->gt, "\n\tASID: %d\n"
> +	xe_gt_info(pf->gt, "\n\tASID: %ld\n"
>  		   "\tFaulted Address: 0x%08x%08x\n"
>  		   "\tFaultType: %lu\n"
>  		   "\tAccessType: %lu\n"
>  		   "\tFaultLevel: %lu\n"
>  		   "\tEngineClass: %d %s\n"
> -		   "\tEngineInstance: %d\n",
> -		   pf->consumer.asid,
> +		   "\tEngineInstance: %d\n"
> +		   "\tSRCID: 0x%02lx\n",
> +		   FIELD_GET(XE_PAGEFAULT_ASID_MASK,
> +			     pf->consumer.id),
>  		   upper_32_bits(pf->consumer.page_addr),
>  		   lower_32_bits(pf->consumer.page_addr),
>  		   FIELD_GET(XE_PAGEFAULT_TYPE_MASK,
> @@ -260,7 +263,9 @@ static void xe_pagefault_print(struct xe_pagefault *pf)
>  			     pf->consumer.fault_type_level),
>  		   pf->consumer.engine_class,
>  		   xe_hw_engine_class_to_str(pf->consumer.engine_class),
> -		   pf->consumer.engine_instance);
> +		   pf->consumer.engine_instance,
> +		   FIELD_GET(XE_PAGEFAULT_SRCID_MASK,
> +			     pf->consumer.id));
>  }
>  
>  static void xe_pagefault_save_to_vm(struct xe_device *xe, struct xe_pagefault *pf)
> @@ -273,7 +278,8 @@ static void xe_pagefault_save_to_vm(struct xe_device *xe, struct xe_pagefault *p
>  	 * mode, return VM anyways.
>  	 */
>  	down_read(&xe->usm.lock);
> -	vm = xa_load(&xe->usm.asid_to_vm, pf->consumer.asid);
> +	vm = xa_load(&xe->usm.asid_to_vm,
> +		     FIELD_GET(XE_PAGEFAULT_ASID_MASK, pf->consumer.id));
>  	if (vm)
>  		xe_vm_get(vm);
>  	else
> @@ -474,8 +480,9 @@ static bool xe_pagefault_queue_full(struct xe_pagefault_queue *pf_queue)
>   */
>  int xe_pagefault_handler(struct xe_device *xe, struct xe_pagefault *pf)
>  {
> +	u32 asid = FIELD_GET(XE_PAGEFAULT_ASID_MASK, pf->consumer.id);

Same nit as above.

Otherwise LGTM.

Matt

>  	struct xe_pagefault_queue *pf_queue = xe->usm.pf_queue +
> -		(pf->consumer.asid % XE_PAGEFAULT_QUEUE_COUNT);
> +		(asid % XE_PAGEFAULT_QUEUE_COUNT);
>  	unsigned long flags;
>  	bool full;
>  
> @@ -489,7 +496,7 @@ int xe_pagefault_handler(struct xe_device *xe, struct xe_pagefault *pf)
>  	} else {
>  		drm_warn(&xe->drm,
>  			 "PageFault Queue (%d) full, shouldn't be possible\n",
> -			 pf->consumer.asid % XE_PAGEFAULT_QUEUE_COUNT);
> +			 asid % XE_PAGEFAULT_QUEUE_COUNT);
>  	}
>  	spin_unlock_irqrestore(&pf_queue->lock, flags);
>  
> diff --git a/drivers/gpu/drm/xe/xe_pagefault_types.h b/drivers/gpu/drm/xe/xe_pagefault_types.h
> index c4ee625b93dd..2213cea886c7 100644
> --- a/drivers/gpu/drm/xe/xe_pagefault_types.h
> +++ b/drivers/gpu/drm/xe/xe_pagefault_types.h
> @@ -65,8 +65,13 @@ struct xe_pagefault {
>  	struct {
>  		/** @consumer.page_addr: address of page fault */
>  		u64 page_addr;
> -		/** @consumer.asid: address space ID */
> -		u32 asid;
> +#define XE_PAGEFAULT_ASID_MASK	GENMASK(23, 0)
> +#define XE_PAGEFAULT_SRCID_MASK	GENMASK(31, 24)
> +		/**
> +		 * @consumer.id: address space ID and SRCID, folded into one
> +		 * to keep size compact
> +		 */
> +		u32 id;
>  		/**
>  		 * @consumer.access_type: access type and prefetch flag packed
>  		 * into a u8.
> -- 
> 2.53.0
>