[Attention] Update tests to remove deprecated env vars (#30563)

Signed-off-by: Matthew Bonanni <mbonanni@redhat.com>

tests/engine/test_arg_utils.py

@@ -9,7 +9,7 @@ from typing import Annotated, Literal
 
 import pytest
 
-from vllm.config import CompilationConfig, config
+from vllm.config import AttentionConfig, CompilationConfig, config
 from vllm.engine.arg_utils import (
     EngineArgs,
     contains_type,
@@ -298,6 +298,139 @@ def test_compilation_config():
     )
 
 
+def test_attention_config():
+    from vllm.attention.backends.registry import AttentionBackendEnum
+
+    parser = EngineArgs.add_cli_args(FlexibleArgumentParser())
+
+    # default value
+    args = parser.parse_args([])
+    assert args is not None
+    engine_args = EngineArgs.from_cli_args(args)
+    assert engine_args.attention_config == AttentionConfig()
+
+    # set backend via dot notation
+    args = parser.parse_args(["--attention-config.backend", "FLASH_ATTN"])
+    assert args is not None
+    engine_args = EngineArgs.from_cli_args(args)
+    assert engine_args.attention_config.backend is not None
+    assert engine_args.attention_config.backend.name == "FLASH_ATTN"
+
+    # set backend via --attention-backend shorthand
+    args = parser.parse_args(["--attention-backend", "FLASHINFER"])
+    assert args is not None
+    engine_args = EngineArgs.from_cli_args(args)
+    assert engine_args.attention_backend is not None
+    assert engine_args.attention_backend == "FLASHINFER"
+
+    # set all fields via dot notation
+    args = parser.parse_args(
+        [
+            "--attention-config.backend",
+            "FLASH_ATTN",
+            "--attention-config.flash_attn_version",
+            "3",
+            "--attention-config.use_prefill_decode_attention",
+            "true",
+            "--attention-config.flash_attn_max_num_splits_for_cuda_graph",
+            "16",
+            "--attention-config.use_cudnn_prefill",
+            "true",
+            "--attention-config.use_trtllm_ragged_deepseek_prefill",
+            "true",
+            "--attention-config.use_trtllm_attention",
+            "true",
+            "--attention-config.disable_flashinfer_prefill",
+            "true",
+            "--attention-config.disable_flashinfer_q_quantization",
+            "true",
+        ]
+    )
+    assert args is not None
+    engine_args = EngineArgs.from_cli_args(args)
+    assert engine_args.attention_config.backend is not None
+    assert engine_args.attention_config.backend.name == "FLASH_ATTN"
+    assert engine_args.attention_config.flash_attn_version == 3
+    assert engine_args.attention_config.use_prefill_decode_attention is True
+    assert engine_args.attention_config.flash_attn_max_num_splits_for_cuda_graph == 16
+    assert engine_args.attention_config.use_cudnn_prefill is True
+    assert engine_args.attention_config.use_trtllm_ragged_deepseek_prefill is True
+    assert engine_args.attention_config.use_trtllm_attention is True
+    assert engine_args.attention_config.disable_flashinfer_prefill is True
+    assert engine_args.attention_config.disable_flashinfer_q_quantization is True
+
+    # set to string form of a dict with all fields
+    args = parser.parse_args(
+        [
+            "--attention-config="
+            '{"backend": "FLASHINFER", "flash_attn_version": 2, '
+            '"use_prefill_decode_attention": false, '
+            '"flash_attn_max_num_splits_for_cuda_graph": 8, '
+            '"use_cudnn_prefill": false, '
+            '"use_trtllm_ragged_deepseek_prefill": false, '
+            '"use_trtllm_attention": false, '
+            '"disable_flashinfer_prefill": false, '
+            '"disable_flashinfer_q_quantization": false}',
+        ]
+    )
+    assert args is not None
+    engine_args = EngineArgs.from_cli_args(args)
+    assert engine_args.attention_config.backend is not None
+    assert engine_args.attention_config.backend.name == "FLASHINFER"
+    assert engine_args.attention_config.flash_attn_version == 2
+    assert engine_args.attention_config.use_prefill_decode_attention is False
+    assert engine_args.attention_config.flash_attn_max_num_splits_for_cuda_graph == 8
+    assert engine_args.attention_config.use_cudnn_prefill is False
+    assert engine_args.attention_config.use_trtllm_ragged_deepseek_prefill is False
+    assert engine_args.attention_config.use_trtllm_attention is False
+    assert engine_args.attention_config.disable_flashinfer_prefill is False
+    assert engine_args.attention_config.disable_flashinfer_q_quantization is False
+
+    # test --attention-backend flows into VllmConfig.attention_config
+    args = parser.parse_args(
+        [
+            "--model",
+            "facebook/opt-125m",
+            "--attention-backend",
+            "FLASH_ATTN",
+        ]
+    )
+    assert args is not None
+    engine_args = EngineArgs.from_cli_args(args)
+    vllm_config = engine_args.create_engine_config()
+    assert vllm_config.attention_config.backend == AttentionBackendEnum.FLASH_ATTN
+
+    # test --attention-config.backend flows into VllmConfig.attention_config
+    args = parser.parse_args(
+        [
+            "--model",
+            "facebook/opt-125m",
+            "--attention-config.backend",
+            "FLASHINFER",
+        ]
+    )
+    assert args is not None
+    engine_args = EngineArgs.from_cli_args(args)
+    vllm_config = engine_args.create_engine_config()
+    assert vllm_config.attention_config.backend == AttentionBackendEnum.FLASHINFER
+
+    # test --attention-backend and --attention-config.backend are mutually exclusive
+    args = parser.parse_args(
+        [
+            "--model",
+            "facebook/opt-125m",
+            "--attention-backend",
+            "FLASH_ATTN",
+            "--attention-config.backend",
+            "FLASHINFER",
+        ]
+    )
+    assert args is not None
+    engine_args = EngineArgs.from_cli_args(args)
+    with pytest.raises(ValueError, match="mutually exclusive"):
+        engine_args.create_engine_config()
+
+
 def test_prefix_cache_default():
     parser = EngineArgs.add_cli_args(FlexibleArgumentParser())
     args = parser.parse_args([])