drm/xe/pf: Save VF GuC state when pausing VF

Since usually pausing the VF is done as a first step to migrate
that VF, immediately save VF GuC state as a final step of the VF
pausing to have that data ready to export when needed.

Signed-off-by: Michal Wajdeczko <[e-mail]>
Cc: Michał Winiarski <[e-mail]>
Cc: Tomasz Lis <[e-mail]>
Reviewed-by: Michał Winiarski <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c

···
 #include "xe_gt_sriov_pf_config.h"
 #include "xe_gt_sriov_pf_control.h"
 #include "xe_gt_sriov_pf_helpers.h"
+#include "xe_gt_sriov_pf_migration.h"
 #include "xe_gt_sriov_pf_monitor.h"
 #include "xe_gt_sriov_pf_service.h"
 #include "xe_gt_sriov_printk.h"
···
 	CASE2STR(PAUSE_SEND_PAUSE);
 	CASE2STR(PAUSE_WAIT_GUC);
 	CASE2STR(PAUSE_GUC_DONE);
+	CASE2STR(PAUSE_SAVE_GUC);
 	CASE2STR(PAUSE_FAILED);
 	CASE2STR(PAUSED);
 	CASE2STR(RESUME_WIP);
···
  *	:        |                                      :             /
  *	:        v                                      :            /
  *	:       PAUSE_GUC_DONE                          o-----restart
+ *	:        |                                      :
+ *	:        |   o---<--busy                        :
+ *	:        v  /         /                         :
+ *	:       PAUSE_SAVE_GUC                          :
  *	:      /                                        :
  *	:     /                                         :
  *	:....o..............o...............o...........:
···
 		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);
 	}
 }
 
···
 	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_completed(gt, vfid);
+	pf_enter_vf_pause_save_guc(gt, vfid);
 	return true;
 }
 
···
 	}
 
 	if (pf_exit_vf_pause_guc_done(gt, vfid))
+		return true;
+
+	if (pf_exit_vf_pause_save_guc(gt, vfid))
 		return true;
 
 	if (pf_exit_vf_resume_send_resume(gt, vfid))

drivers/gpu/drm/xe/xe_gt_sriov_pf_control_types.h

···
  * @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_RESUME_WIP: indicates the a VF resume operation is in progress.
···
 	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,