[PATCH 4/5] drm/xe/vf: Stop applying save-restore MMIOs if VF

[Matt Roper]

On Mon, Mar 03, 2025 at 06:35:21PM +0100, Michal Wajdeczko wrote:
> Currently we are blocking processing of all save-restore rules
> by the VFs inside the xe_rtp_process_to_sr() function, but we
> want to unblock that to allow processing of the LRC WA rules.
> 
> To avoid hitting WARNs about reading an inaccessible registers by
> the VFs, stop applying save-restore MMIOs action if VF, without
> relying that SR list will be always empty for the VF.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Matt Roper <matthew.d.roper at intel.com>

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

> ---
>  drivers/gpu/drm/xe/xe_reg_sr.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_reg_sr.c b/drivers/gpu/drm/xe/xe_reg_sr.c
> index 9475e3f74958..fc8447a838c4 100644
> --- a/drivers/gpu/drm/xe/xe_reg_sr.c
> +++ b/drivers/gpu/drm/xe/xe_reg_sr.c
> @@ -173,6 +173,9 @@ void xe_reg_sr_apply_mmio(struct xe_reg_sr *sr, struct xe_gt *gt)
>  	if (xa_empty(&sr->xa))
>  		return;
>  
> +	if (IS_SRIOV_VF(gt_to_xe(gt)))
> +		return;
> +
>  	xe_gt_dbg(gt, "Applying %s save-restore MMIOs\n", sr->name);
>  
>  	fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FORCEWAKE_ALL);
> -- 
> 2.47.1
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation