drm/xe/vf: Start re-emission from first unsignaled job during VF migration

The LRC software ring tail is reset to the first unsignaled pending
job's head.

Fix the re-emission logic to begin submitting from the first unsignaled
job detected, rather than scanning all pending jobs, which can cause
imbalance.

v2:
 - Include missing local changes
v3:
 - s/skip_replay/restore_replay (Tomasz)

Fixes: c25c101 ("drm/xe/vf: Replay GuC submission state on pause / unpause")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Tomasz Lis <tomasz.lis@intel.com>
Link: https://patch.msgid.link/20251121152750.240557-1-matthew.brost@intel.com
(cherry picked from commit 00937fe)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

Author: mbrost05

drivers/gpu/drm/xe/xe_gpu_scheduler.h

@@ -54,13 +54,14 @@ static inline void xe_sched_tdr_queue_imm(struct xe_gpu_scheduler *sched)
 static inline void xe_sched_resubmit_jobs(struct xe_gpu_scheduler *sched)
 {
 	struct drm_sched_job *s_job;
+	bool restore_replay = false;
 
 	list_for_each_entry(s_job, &sched->base.pending_list, list) {
 		struct drm_sched_fence *s_fence = s_job->s_fence;
 		struct dma_fence *hw_fence = s_fence->parent;
 
-		if (to_xe_sched_job(s_job)->skip_emit ||
-		    (hw_fence && !dma_fence_is_signaled(hw_fence)))
+		restore_replay |= to_xe_sched_job(s_job)->restore_replay;
+		if (restore_replay || (hw_fence && !dma_fence_is_signaled(hw_fence)))
 			sched->base.ops->run_job(s_job);
 	}
 }

drivers/gpu/drm/xe/xe_guc_submit.c

@@ -822,7 +822,7 @@ static void submit_exec_queue(struct xe_exec_queue *q, struct xe_sched_job *job)
 
 	xe_gt_assert(guc_to_gt(guc), exec_queue_registered(q));
 
-	if (!job->skip_emit || job->last_replay) {
+	if (!job->restore_replay || job->last_replay) {
 		if (xe_exec_queue_is_parallel(q))
 			wq_item_append(q);
 		else
@@ -881,10 +881,10 @@ guc_exec_queue_run_job(struct drm_sched_job *drm_job)
 	if (!killed_or_banned_or_wedged && !xe_sched_job_is_error(job)) {
 		if (!exec_queue_registered(q))
 			register_exec_queue(q, GUC_CONTEXT_NORMAL);
-		if (!job->skip_emit)
+		if (!job->restore_replay)
 			q->ring_ops->emit_job(job);
 		submit_exec_queue(q, job);
-		job->skip_emit = false;
+		job->restore_replay = false;
 	}
 
 	/*
@@ -2152,6 +2152,8 @@ static void guc_exec_queue_pause(struct xe_guc *guc, struct xe_exec_queue *q)
 
 	job = xe_sched_first_pending_job(sched);
 	if (job) {
+		job->restore_replay = true;
+
 		/*
 		 * Adjust software tail so jobs submitted overwrite previous
 		 * position in ring buffer with new GGTT addresses.
@@ -2241,17 +2243,18 @@ static void guc_exec_queue_unpause_prepare(struct xe_guc *guc,
 					   struct xe_exec_queue *q)
 {
 	struct xe_gpu_scheduler *sched = &q->guc->sched;
-	struct drm_sched_job *s_job;
 	struct xe_sched_job *job = NULL;
+	bool restore_replay = false;
 
-	list_for_each_entry(s_job, &sched->base.pending_list, list) {
-		job = to_xe_sched_job(s_job);
-
-		xe_gt_dbg(guc_to_gt(guc), "Replay JOB - guc_id=%d, seqno=%d",
-			  q->guc->id, xe_sched_job_seqno(job));
+	list_for_each_entry(job, &sched->base.pending_list, drm.list) {
+		restore_replay |= job->restore_replay;
+		if (restore_replay) {
+			xe_gt_dbg(guc_to_gt(guc), "Replay JOB - guc_id=%d, seqno=%d",
+				  q->guc->id, xe_sched_job_seqno(job));
 
-		q->ring_ops->emit_job(job);
-		job->skip_emit = true;
+			q->ring_ops->emit_job(job);
+			job->restore_replay = true;
+		}
 	}
 
 	if (job)

drivers/gpu/drm/xe/xe_sched_job_types.h

@@ -63,8 +63,8 @@ struct xe_sched_job {
 	bool ring_ops_flush_tlb;
 	/** @ggtt: mapped in ggtt. */
 	bool ggtt;
-	/** @skip_emit: skip emitting the job */
-	bool skip_emit;
+	/** @restore_replay: job being replayed for restore */
+	bool restore_replay;
 	/** @last_replay: last job being replayed */
 	bool last_replay;
 	/** @ptrs: per instance pointers. */