Re: [PATCH 14/26] drm/xe/pf: Don't save GuC VF migration data on pause

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

On 10/11/2025 9:38 PM, Michał Winiarski wrote:
> In upcoming changes, the GuC VF migration data will be handled as part
> of separate SAVE/RESTORE states in VF control state machine.
> Remove it from PAUSE state.

still waiting for the full SAVE/RESTORE state diagrams,
but that split makes sense, as this extra SAVE_GUC step was for early-debug, so:

Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>

> 
> Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c   | 39 +------------------
>  .../gpu/drm/xe/xe_gt_sriov_pf_control_types.h |  2 -
>  2 files changed, 2 insertions(+), 39 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> index 092d3d710bca1..6ece775b2e80e 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
> @@ -183,7 +183,6 @@ static const char *control_bit_to_string(enum xe_gt_sriov_control_bits bit)
>  	CASE2STR(PAUSE_SEND_PAUSE);
>  	CASE2STR(PAUSE_WAIT_GUC);
>  	CASE2STR(PAUSE_GUC_DONE);
> -	CASE2STR(PAUSE_SAVE_GUC);
>  	CASE2STR(PAUSE_FAILED);
>  	CASE2STR(PAUSED);
>  	CASE2STR(MIGRATION_DATA_WIP);
> @@ -451,8 +450,7 @@ static void pf_enter_vf_ready(struct xe_gt *gt, unsigned int vfid)
>   *	:       PAUSE_GUC_DONE                          o-----restart
>   *	:        |                                      :
>   *	:        |   o---<--busy                        :
> - *	:        v  /         /                         :
> - *	:       PAUSE_SAVE_GUC                          :
> + *	:       /                                       :
>   *	:      /                                        :
>   *	:     /                                         :
>   *	:....o..............o...............o...........:
> @@ -472,7 +470,6 @@ static void pf_exit_vf_pause_wip(struct xe_gt *gt, unsigned int vfid)
>  		pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_PAUSE_SEND_PAUSE);
>  		pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_PAUSE_WAIT_GUC);
>  		pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_PAUSE_GUC_DONE);
> -		pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_PAUSE_SAVE_GUC);
>  	}
>  }
>  
> @@ -503,41 +500,12 @@ static void pf_enter_vf_pause_rejected(struct xe_gt *gt, unsigned int vfid)
>  	pf_enter_vf_pause_failed(gt, vfid);
>  }
>  
> -static void pf_enter_vf_pause_save_guc(struct xe_gt *gt, unsigned int vfid)
> -{
> -	if (!pf_enter_vf_state(gt, vfid, XE_GT_SRIOV_STATE_PAUSE_SAVE_GUC))
> -		pf_enter_vf_state_machine_bug(gt, vfid);
> -}
> -
> -static bool pf_exit_vf_pause_save_guc(struct xe_gt *gt, unsigned int vfid)
> -{
> -	int err;
> -
> -	if (!pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_PAUSE_SAVE_GUC))
> -		return false;
> -
> -	err = xe_gt_sriov_pf_migration_save_guc_state(gt, vfid);
> -	if (err) {
> -		/* retry if busy */
> -		if (err == -EBUSY) {
> -			pf_enter_vf_pause_save_guc(gt, vfid);
> -			return true;
> -		}
> -		/* give up on error */
> -		if (err == -EIO)
> -			pf_enter_vf_mismatch(gt, vfid);
> -	}
> -
> -	pf_enter_vf_pause_completed(gt, vfid);
> -	return true;
> -}
> -
>  static bool pf_exit_vf_pause_guc_done(struct xe_gt *gt, unsigned int vfid)
>  {
>  	if (!pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_PAUSE_GUC_DONE))
>  		return false;
>  
> -	pf_enter_vf_pause_save_guc(gt, vfid);
> +	pf_enter_vf_pause_completed(gt, vfid);
>  	return true;
>  }
>  
> @@ -1788,9 +1756,6 @@ static bool pf_process_vf_state_machine(struct xe_gt *gt, unsigned int vfid)
>  	if (pf_exit_vf_pause_guc_done(gt, vfid))
>  		return true;
>  
> -	if (pf_exit_vf_pause_save_guc(gt, vfid))
> -		return true;
> -
>  	if (pf_handle_vf_save_wip(gt, vfid))
>  		return true;
>  
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h
> index 02b517533ee8a..68ec9d1fc3daf 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h
> @@ -28,7 +28,6 @@
>   * @XE_GT_SRIOV_STATE_PAUSE_SEND_PAUSE: indicates that the PF is about to send a PAUSE command.
>   * @XE_GT_SRIOV_STATE_PAUSE_WAIT_GUC: indicates that the PF awaits for a response from the GuC.
>   * @XE_GT_SRIOV_STATE_PAUSE_GUC_DONE: indicates that the PF has received a response from the GuC.
> - * @XE_GT_SRIOV_STATE_PAUSE_SAVE_GUC: indicates that the PF needs to save the VF GuC state.
>   * @XE_GT_SRIOV_STATE_PAUSE_FAILED: indicates that a VF pause operation has failed.
>   * @XE_GT_SRIOV_STATE_PAUSED: indicates that the VF is paused.
>   * @XE_GT_SRIOV_STATE_MIGRATION_DATA_WIP: indicates that the new data is expected in migration ring.
> @@ -66,7 +65,6 @@ enum xe_gt_sriov_control_bits {
>  	XE_GT_SRIOV_STATE_PAUSE_SEND_PAUSE,
>  	XE_GT_SRIOV_STATE_PAUSE_WAIT_GUC,
>  	XE_GT_SRIOV_STATE_PAUSE_GUC_DONE,
> -	XE_GT_SRIOV_STATE_PAUSE_SAVE_GUC,
>  	XE_GT_SRIOV_STATE_PAUSE_FAILED,
>  	XE_GT_SRIOV_STATE_PAUSED,
>