[V1] [Hybrid] Enable Full CUDA Graph (decode-only) for Mamba layers (#21401)

Signed-off-by: Thomas Parnell <tpa@zurich.ibm.com>

tests/models/language/generation/test_hybrid.py

@@ -384,3 +384,63 @@ def test_distributed_correctness(
         name_0="vllm_tp_1",
         name_1="vllm_tp_2",
     )
+
+
+@pytest.mark.parametrize("model", ["Zyphra/Zamba2-1.2B-instruct"])
+@pytest.mark.parametrize("max_tokens", [64])
+@pytest.mark.parametrize("num_logprobs", [5])
+def test_full_cuda_graph(
+    hf_runner,
+    vllm_runner,
+    example_prompts,
+    monkeypatch,
+    model: str,
+    max_tokens: int,
+    num_logprobs: int,
+) -> None:
+
+    try:
+        model_info = HF_EXAMPLE_MODELS.find_hf_info(model)
+        model_info.check_available_online(on_fail="skip")
+        model_info.check_transformers_version(on_fail="skip")
+    except ValueError:
+        pass
+
+    with hf_runner(model) as hf_model:
+        if model not in HF_UNSUPPORTED_MODELS:
+            hf_outputs = hf_model.generate_greedy_logprobs_limit(
+                example_prompts, max_tokens, num_logprobs)
+        else:
+            hf_outputs = None
+
+    with vllm_runner(model, max_num_seqs=MAX_NUM_SEQS) as vllm_model:
+        vllm_v0_outputs = vllm_model.generate_greedy_logprobs(
+            example_prompts, max_tokens, num_logprobs)
+
+    with monkeypatch.context() as m:
+        m.setenv("VLLM_USE_V1", "1")
+        if model in HYBRID_MODELS:
+            # required due to reorder_batch behaviour
+            m.setenv("VLLM_ATTENTION_BACKEND", "FLASHINFER")
+        with vllm_runner(model,
+                         max_num_seqs=MAX_NUM_SEQS,
+                         compilation_config={'full_cuda_graph': True},
+                         enable_prefix_caching=False) as vllm_model:
+            vllm_v1_outputs = vllm_model.generate_greedy_logprobs(
+                example_prompts, max_tokens, num_logprobs)
+
+    if hf_outputs is not None:
+        check_logprobs_close(
+            outputs_0_lst=hf_outputs,
+            outputs_1_lst=vllm_v0_outputs,
+            name_0="hf",
+            name_1="vllm-v0",
+        )
+
+    ref_outputs = hf_outputs if hf_outputs is not None else vllm_v0_outputs
+    check_logprobs_close(
+        outputs_0_lst=ref_outputs,
+        outputs_1_lst=vllm_v1_outputs,
+        name_0="hf" if hf_outputs is not None else "vllm-v0",
+        name_1="vllm-v1",
+    )