diff --git a/drivers/gpu/drm/xe/xe_ring_ops.c b/drivers/gpu/drm/xe/xe_ring_ops.c
index 3dd8cf4e2131..bc4dea606b38 100644
--- a/drivers/gpu/drm/xe/xe_ring_ops.c
+++ b/drivers/gpu/drm/xe/xe_ring_ops.c
@@ -504,6 +504,68 @@ static void __emit_job_gen12_render_compute(struct xe_sched_job *job,
 	xe_lrc_write_ring(lrc, dw, i * sizeof(*dw));
 }
 
+static int emit_ulls_preamble(struct xe_lrc *lrc, u32 *dw, int i, u32 seqno)
+{
+	u32 addr = xe_lrc_ulls_semaphore_ggtt_addr(lrc, seqno);
+
+	return emit_store_imm_ggtt(addr, LRC_MIGRATION_ULLS_SEMAPHORE_CLEAR,
+				   dw, i);
+}
+
+/*
+ * Advance the ring tail from within the ring, so submitting the next ULLS job
+ * needs nothing from the CPU beyond signalling the semaphore. All ULLS jobs
+ * occupy exactly ULLS_JOB_SIZE_BYTES, so the tail the next job ends at is two
+ * job slots on from where this job started, even though that job has not been
+ * emitted yet. Both LRC and MMIO ring tail advanced in step.
+ */
+static int emit_ulls_ring_tail(struct xe_gt *gt, struct xe_lrc *lrc, u32 *dw,
+			       int i, u32 head)
+{
+	u32 next_tail = (head + 2 * ULLS_JOB_SIZE_BYTES) & (lrc->ring.size - 1);
+
+	xe_gt_assert(gt, IS_ALIGNED(next_tail, 8));
+
+	i = emit_store_imm_ggtt(xe_lrc_ring_tail_ggtt_addr(lrc), next_tail,
+				dw, i);
+
+	dw[i++] = MI_LOAD_REGISTER_IMM | MI_LRI_NUM_REGS(1) |
+		MI_LRI_LRM_CS_MMIO;
+	dw[i++] = RING_TAIL(0).addr;
+	dw[i++] = next_tail;
+
+	return i;
+}
+
+/* Publish the next job's tail, then park the engine on its semaphore */
+static int emit_ulls_postamble(struct xe_gt *gt, struct xe_lrc *lrc, u32 *dw,
+			       int i, u32 seqno, u32 head)
+{
+	i = emit_ulls_ring_tail(gt, lrc, dw, i, head);
+
+	dw[i++] = MI_SEMAPHORE_WAIT |
+		MI_SEMW_GGTT |
+		MI_SEMW_POLL |
+		MI_SEMW_COMPARE(SAD_EQ_SDD);
+	dw[i++] = LRC_MIGRATION_ULLS_SEMAPHORE_SIGNAL;
+	dw[i++] = xe_lrc_ulls_semaphore_ggtt_addr(lrc, seqno + 1);
+	dw[i++] = 0;
+	dw[i++] = 0;
+
+	return i;
+}
+
+/* Pad out to the fixed ULLS job size */
+static int emit_ulls_pad(struct xe_gt *gt, u32 *dw, int i)
+{
+	xe_gt_assert(gt, i <= ULLS_JOB_SIZE_DW);
+
+	while (i < ULLS_JOB_SIZE_DW)
+		dw[i++] = MI_NOOP;
+
+	return i;
+}
+
 static void emit_migration_job_gen12(struct xe_sched_job *job,
 				     struct xe_lrc *lrc, u32 *head,
 				     u32 seqno)
@@ -517,10 +579,16 @@ static void emit_migration_job_gen12(struct xe_sched_job *job,
 
 	xe_gt_assert(gt, !job->ring_ops_force_reset);
 
+	if (xe_sched_job_is_ulls(job))
+		i = emit_ulls_preamble(lrc, dw, i, seqno);
+
 	i = emit_copy_timestamp(xe, lrc, dw, i);
 
 	i = emit_store_imm_ggtt(saddr, seqno, dw, i);
 
+	if (!xe_sched_job_ulls_has_batch(job))
+		goto seqno_write;
+
 	dw[i++] = MI_ARB_ON_OFF | MI_ARB_DISABLE; /* Enabled again below */
 
 	i = emit_bb_start(job->ptrs[0].batch_addr, BIT(8), dw, i);
@@ -531,12 +599,19 @@ static void emit_migration_job_gen12(struct xe_sched_job *job,
 
 	i = emit_bb_start(job->ptrs[1].batch_addr, BIT(8), dw, i);
 
+seqno_write:
 	i = emit_flush_imm_ggtt(xe_lrc_seqno_ggtt_addr(lrc), seqno,
 				job->migrate_flush_flags,
 				dw, i);
 
 	i = emit_user_interrupt(dw, i);
 
+	if (xe_sched_job_ulls_parks(job))
+		i = emit_ulls_postamble(gt, lrc, dw, i, seqno, *head);
+
+	if (xe_sched_job_is_ulls(job))
+		i = emit_ulls_pad(gt, dw, i);
+
 	xe_gt_assert(job->q->gt, i <= MAX_JOB_SIZE_DW);
 
 	xe_lrc_write_ring(lrc, dw, i * sizeof(*dw));
diff --git a/drivers/gpu/drm/xe/xe_ring_ops_types.h b/drivers/gpu/drm/xe/xe_ring_ops_types.h
index 52ff96bc4100..ea4af321dd7c 100644
--- a/drivers/gpu/drm/xe/xe_ring_ops_types.h
+++ b/drivers/gpu/drm/xe/xe_ring_ops_types.h
@@ -6,6 +6,7 @@
 #ifndef _XE_RING_OPS_TYPES_H_
 #define _XE_RING_OPS_TYPES_H_
 
+#include <linux/build_bug.h>
 #include <linux/types.h>
 
 struct xe_gt;
@@ -14,6 +15,29 @@ struct xe_sched_job;
 #define MAX_JOB_SIZE_DW 74
 #define MAX_JOB_SIZE_BYTES (MAX_JOB_SIZE_DW * 4)
 
+/*
+ * ULLS migration jobs advance the ring tail from within the ring itself, so a
+ * job has to know where its successor will end before that successor has been
+ * emitted. Every ULLS job is therefore padded to a fixed size, letting the
+ * next tail be derived arithmetically.
+ *
+ * Sized for the largest such job, emitted by emit_migration_job_gen12():
+ * preamble (4), copy timestamp (8, its size on an SRIOV VF), start seqno
+ * store (4), arbitration off (1), batch buffer starts (2 * 3), pre-parser
+ * bracketed flush invalidate (6), seqno flush (4), user interrupt (3) and
+ * postamble (7 + 5).
+ */
+#define ULLS_JOB_SIZE_DW 48
+#define ULLS_JOB_SIZE_BYTES (ULLS_JOB_SIZE_DW * 4)
+
+/*
+ * RING_TAIL only encodes a qword aligned offset, and xe_lrc_write_ring()
+ * appends a NOP to anything shorter, either of which would desynchronise the
+ * ring from the tail a job predicts for its successor.
+ */
+static_assert(ULLS_JOB_SIZE_BYTES % 8 == 0);
+static_assert(ULLS_JOB_SIZE_DW <= MAX_JOB_SIZE_DW);
+
 /**
  * struct xe_ring_ops - Ring operations
  */