[Intel-xe] [PATCH 2/2] drm/xe/xe2: Respond to TRTT faults as unsuccessful page fault

[Matthew Brost]

On Tue, Nov 28, 2023 at 01:36:34PM -0800, Brian Welty wrote:
> SW is not expected to handle TRTT faults and should report these as
> unsuccessful page fault in the reply, such that HW can respond by
> raising a CAT error.
> 
> Signed-off-by: Brian Welty <brian.welty at intel.com>

Reviewed-by: Matthew Brost <matthew.brost at intel.com>

> ---
>  drivers/gpu/drm/xe/xe_gt_pagefault.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c
> index 959ea50c04db..2ee7005d7e39 100644
> --- a/drivers/gpu/drm/xe/xe_gt_pagefault.c
> +++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c
> @@ -33,6 +33,7 @@ struct pagefault {
>  	u8 engine_class;
>  	u8 engine_instance;
>  	u8 fault_unsuccessful;
> +	bool trva_fault;
>  };
>  
>  enum access_type {
> @@ -137,6 +138,10 @@ static int handle_pagefault(struct xe_gt *gt, struct pagefault *pf)
>  	int ret = 0;
>  	bool atomic;
>  
> +	/* SW isn't expected to handle TRTT faults */
> +	if (pf->trva_fault)
> +		return -EFAULT;
> +
>  	/* ASID to VM */
>  	mutex_lock(&xe->usm.lock);
>  	vm = xa_load(&xe->usm.asid_to_vm, pf->asid);
> @@ -281,6 +286,7 @@ static bool get_pagefault(struct pf_queue *pf_queue, struct pagefault *pf)
>  			(pf_queue->data + pf_queue->head);
>  
>  		pf->fault_level = FIELD_GET(PFD_FAULT_LEVEL, desc->dw0);
> +		pf->trva_fault = FIELD_GET(XE2_PFD_TRVA_FAULT, desc->dw0);
>  		pf->engine_class = FIELD_GET(PFD_ENG_CLASS, desc->dw0);
>  		pf->engine_instance = FIELD_GET(PFD_ENG_INSTANCE, desc->dw0);
>  		pf->pdata = FIELD_GET(PFD_PDATA_HI, desc->dw1) <<
> -- 
> 2.38.0
>