[PP][DeepSeek V4] Overlap communication and optimize SM120 prefill (#38792)

Co-authored-by: Yangmin Li <yangminl@nvidia.com>
Co-authored-by: YAMY <74099316+YAMY1234@users.noreply.github.com>

test/registered/unit/disaggregation/test_disaggregation_wire.py

@@ -927,6 +927,7 @@ def _make_dsv4_draft(*, unified, mapping=None):
     pool._unified_kv = unified
     pool.compression_ratios = [0]
     pool.page_size = 256
+    pool.swa_page_size = 256
     pool.sliding_window = 128
     pool.full_to_swa_index_mapping = mapping
     pool.unified_swa_window = 128
@@ -941,7 +942,7 @@ def _make_dsv4_draft(*, unified, mapping=None):
         )
     else:
         pool.swa_kv_pool = SimpleNamespace(
-            kv_buffer=[torch.empty((2, 16), dtype=torch.uint8)]
+            page_size=256, kv_buffer=[torch.empty((2, 16), dtype=torch.uint8)]
         )
     return pool