[Model] New model support for microsoft/Phi-4-mini-flash-reasoning (#20702)

Signed-off-by: Congcong Chen <congcongchen@microsoft.com>

csrc/mamba/mamba_ssm/selective_scan_fwd.cu

@@ -312,8 +312,8 @@ void selective_scan_fwd_launch(SSMParamsBase &params, cudaStream_t stream) {
     // kIsVariableB, kIsVariableC and kHasZ are all set to True to reduce binary size
     constexpr bool kIsVariableB = true;
     constexpr bool kIsVariableC = true;
-    constexpr bool kHasZ = true;
     BOOL_SWITCH(params.seqlen % (kNThreads * kNItems) == 0, kIsEvenLen, [&] {
+        BOOL_SWITCH(params.z_ptr != nullptr , kHasZ, [&] {
             BOOL_SWITCH(params.query_start_loc_ptr != nullptr , kVarlen, [&] {
                 using Ktraits = Selective_Scan_fwd_kernel_traits<kNThreads, kNItems, kNRows, kIsEvenLen, kIsVariableB, kIsVariableC, kHasZ,  kVarlen, input_t, weight_t>;
                 constexpr int kSmemSize = Ktraits::kSmemSize + kNRows * MAX_DSTATE * sizeof(typename Ktraits::scan_t);
@@ -321,12 +321,13 @@ void selective_scan_fwd_launch(SSMParamsBase &params, cudaStream_t stream) {
                 auto kernel = &selective_scan_fwd_kernel<Ktraits>;
                 if (kSmemSize >= 48 * 1024) {
                     C10_CUDA_CHECK(cudaFuncSetAttribute(
-                    (void *) kernel, cudaFuncAttributeMaxDynamicSharedMemorySize, kSmemSize));
+                        kernel, cudaFuncAttributeMaxDynamicSharedMemorySize, kSmemSize));
                 }
                 kernel<<<grid, Ktraits::kNThreads, kSmemSize, stream>>>(params);
                 C10_CUDA_KERNEL_LAUNCH_CHECK();
             });
         });
+    });
 }
 
 template<typename input_t, typename weight_t>
@@ -612,7 +613,7 @@ void selective_scan_fwd(const torch::Tensor &u, const torch::Tensor &delta,
 
     at::Tensor z, out_z;
     const bool has_z = z_.has_value();
-    TORCH_CHECK(has_z, "has_z = False is disabled in favor of reduced binary size")
+    if (has_z) {
         z = z_.value();
         TORCH_CHECK(z.scalar_type() == input_type);
         TORCH_CHECK(z.is_cuda());
@@ -624,6 +625,7 @@ void selective_scan_fwd(const torch::Tensor &u, const torch::Tensor &delta,
         }
         
         out_z = z;
+    }
 
     // Right now u has BHL layout and delta has HBL layout, and we want out to have HBL layout
     at::Tensor out = delta;
@@ -653,4 +655,3 @@ void selective_scan_fwd(const torch::Tensor &u, const torch::Tensor &delta,
         selective_scan_fwd_cuda<input_t, weight_t>(params, stream);
     });
 }
-

docs/models/supported_models.md

@@ -374,6 +374,7 @@ Specified using `--task generate`.
 | `Phi3ForCausalLM` | Phi-4, Phi-3 | `microsoft/Phi-4-mini-instruct`, `microsoft/Phi-4`, `microsoft/Phi-3-mini-4k-instruct`, `microsoft/Phi-3-mini-128k-instruct`, `microsoft/Phi-3-medium-128k-instruct`, etc. | ✅︎ | ✅︎ | ✅︎ |
 | `Phi3SmallForCausalLM` | Phi-3-Small | `microsoft/Phi-3-small-8k-instruct`, `microsoft/Phi-3-small-128k-instruct`, etc. | | ✅︎ | ✅︎ |
 | `PhiMoEForCausalLM` | Phi-3.5-MoE | `microsoft/Phi-3.5-MoE-instruct`, etc. | ✅︎ | ✅︎ | ✅︎ |
+| `Phi4FlashForCausalLM` | Phi-4-mini-flash-reasoning | `microsoft/microsoft/Phi-4-mini-instruct`, etc. | | | |
 | `PersimmonForCausalLM` | Persimmon | `adept/persimmon-8b-base`, `adept/persimmon-8b-chat`, etc. | | ✅︎ | ✅︎ |
 | `Plamo2ForCausalLM` | PLaMo2 | `pfnet/plamo-2-1b`, `pfnet/plamo-2-8b`, etc. | | | |
 | `QWenLMHeadModel` | Qwen | `Qwen/Qwen-7B`, `Qwen/Qwen-7B-Chat`, etc. | ✅︎ | ✅︎ | ✅︎ |

tests/models/registry.py

@@ -248,6 +248,10 @@ _TEXT_GENERATION_EXAMPLE_MODELS = {
     "Phi3SmallForCausalLM": _HfExamplesInfo("microsoft/Phi-3-small-8k-instruct",
                                             trust_remote_code=True,
                                             v0_only=True),
+    "Phi4FlashForCausalLM": _HfExamplesInfo("microsoft/Phi-4-mini-flash-reasoning", # noqa: E501
+                                        trust_remote_code=True,
+                                        v0_only=True,
+                                        max_model_len=10240),
     "PhiMoEForCausalLM": _HfExamplesInfo("microsoft/Phi-3.5-MoE-instruct",
                                          trust_remote_code=True),
     "Plamo2ForCausalLM": _HfExamplesInfo("pfnet/plamo-2-1b",

tests/models/test_initialization.py

@@ -103,6 +103,9 @@ def test_can_initialize(model_arch: str, monkeypatch: pytest.MonkeyPatch):
                        _initialize_kv_caches_v1), monkeypatch.context() as m):
         if model_info.v0_only:
             m.setenv("VLLM_USE_V1", "0")
+        if model_arch == "Phi4FlashForCausalLM":
+            # Phi4FlashForCausalLM only supports DIFFERENTIAL_FLASH_ATTN backend
+            m.setenv("VLLM_ATTENTION_BACKEND", "DIFFERENTIAL_FLASH_ATTN")
         LLM(
             model_info.default,
             tokenizer=model_info.tokenizer,

tests/test_utils.py

@@ -458,6 +458,31 @@ def test_bind_kv_cache():
     assert ctx['layers.2.self_attn'].kv_cache[0] is kv_cache[2]
     assert ctx['layers.3.self_attn'].kv_cache[0] is kv_cache[3]
 
+def test_bind_kv_cache_kv_sharing():
+    from vllm.attention import Attention
+
+    ctx = {
+        'layers.0.self_attn': Attention(32, 128, 0.1),
+        'layers.1.self_attn': Attention(32, 128, 0.1),
+        'layers.2.self_attn': Attention(32, 128, 0.1),
+        'layers.3.self_attn': Attention(32, 128, 0.1),
+    }
+    kv_cache = [
+        torch.zeros((1, )),
+        torch.zeros((1, )),
+        torch.zeros((1, )),
+        torch.zeros((1, )),
+    ]
+    shared_kv_cache_layers = {
+        'layers.2.self_attn': 'layers.1.self_attn',
+        'layers.3.self_attn': 'layers.0.self_attn'
+    }
+    bind_kv_cache(ctx, [kv_cache], shared_kv_cache_layers)
+    assert ctx['layers.0.self_attn'].kv_cache[0] is kv_cache[0]
+    assert ctx['layers.1.self_attn'].kv_cache[0] is kv_cache[1]
+    assert ctx['layers.2.self_attn'].kv_cache[0] is kv_cache[1]
+    assert ctx['layers.3.self_attn'].kv_cache[0] is kv_cache[0]
+
 def test_bind_kv_cache_non_attention():
     from vllm.attention import Attention
 

vllm/attention/backends/blocksparse_attn.py

@@ -308,7 +308,8 @@ class BlocksparseFlashAttentionImpl(AttentionImpl):
         kv_sharing_target_layer_name: Optional[str] = None,
     ) -> None:
         if kv_sharing_target_layer_name is not None:
-            raise NotImplementedError("KV sharing is not supported in V0.")
+            raise NotImplementedError("KV sharing is not supported in V0 "
+                                      "BLOCK_SPARSE_FLASH_ATTN Backend.")
         assert blocksparse_params is not None
         assert alibi_slopes is None, ValueError(
             "Alibi not support for blocksparse flash attention.")

vllm/attention/backends/dual_chunk_flash_attn.py

@@ -295,7 +295,8 @@ class DualChunkFlashAttentionImpl(FlashAttentionImpl):
         dual_chunk_attention_config: Optional[Dict[str, Any]] = None,
     ) -> None:
         if kv_sharing_target_layer_name is not None:
-            raise NotImplementedError("KV sharing is not supported in V0.")
+            raise NotImplementedError("KV sharing is not supported in V0 "
+                                      "DUAL_CHUNK_FLASH_ATTN backend.")
         self.num_heads = num_heads
         self.head_size = head_size
         self.scale = float(scale)

vllm/attention/backends/flash_attn.py

@@ -622,7 +622,8 @@ class FlashAttentionImpl(AttentionImpl):
         use_irope: bool = False,
     ) -> None:
         if kv_sharing_target_layer_name is not None:
-            raise NotImplementedError("KV sharing is not supported in V0.")
+            raise NotImplementedError("KV sharing is not supported in V0 "
+                                      "FLASH_ATTN backend.")
         if blocksparse_params is not None:
             raise ValueError(
                 "FlashAttention does not support block-sparse attention.")

vllm/attention/backends/flashinfer.py

@@ -1006,7 +1006,8 @@ class FlashInferImpl(AttentionImpl):
         use_irope: bool = False,
     ) -> None:
         if kv_sharing_target_layer_name is not None:
-            raise NotImplementedError("KV sharing is not supported in V0.")
+            raise NotImplementedError("KV sharing is not supported in V0 "
+                                      "FLASHINFER backend.")
         if use_irope:
             logger.warning_once(
                 "Using irope in FlashInfer is not supported yet, it will fall"

vllm/attention/backends/hpu_attn.py

@@ -115,7 +115,8 @@ class HPUAttentionImpl(AttentionImpl, torch.nn.Module):
     ) -> None:
         super(AttentionImpl, self).__init__()
         if kv_sharing_target_layer_name is not None:
-            raise NotImplementedError("KV sharing is not supported in V0.")
+            raise NotImplementedError("KV sharing is not supported in V0 "
+                                      "HPU_ATTN backend.")
         if use_irope:
             logger.warning_once(
                 "Using irope in HPU is not supported yet, it will fall back "

vllm/attention/backends/rocm_flash_attn.py

@@ -501,7 +501,8 @@ class ROCmFlashAttentionImpl(AttentionImpl):
         use_irope: bool = False,
     ) -> None:
         if kv_sharing_target_layer_name is not None:
-            raise NotImplementedError("KV sharing is not supported in V0.")
+            raise NotImplementedError("KV sharing is not supported in V0 "
+                                      "ROCM_FLASH backend.")
         if use_irope:
             logger.warning_once(
                 "Using irope in ROCm Flash Attention is not supported yet, it "

vllm/attention/backends/xformers.py

@@ -394,7 +394,8 @@ class XFormersImpl(AttentionImpl[XFormersMetadata]):
         use_irope: bool = False,
     ) -> None:
         if kv_sharing_target_layer_name is not None:
-            raise NotImplementedError("KV sharing is not supported in V0.")
+            raise NotImplementedError("KV sharing is not supported in V0 "
+                                      "XFORMERS backend.")
         if blocksparse_params is not None:
             raise ValueError(
                 "XFormers does not support block-sparse attention.")

vllm/attention/layer.py

@@ -160,10 +160,6 @@ class Attention(nn.Module):
         self.attn_type = attn_type
 
         if kv_sharing_target_layer_name is not None:
-            if not envs.VLLM_USE_V1:
-                raise NotImplementedError(
-                    "Cross-layer KV sharing is not supported in V0.")
-
             validate_kv_sharing_target(
                 prefix,
                 kv_sharing_target_layer_name,

vllm/model_executor/layers/logits_processor.py

@@ -59,11 +59,12 @@ class LogitsProcessor(nn.Module):
         hidden_states: torch.Tensor,
         sampling_metadata: Optional[SamplingMetadata] = None,
         embedding_bias: Optional[torch.Tensor] = None,
+        prune_hidden_states: bool = True,
     ) -> Optional[torch.Tensor]:
         if self.logits_as_input:
             logits = hidden_states
         else:
-            if sampling_metadata is not None:
+            if sampling_metadata is not None and prune_hidden_states:
                 hidden_states = _prune_hidden_states(hidden_states,
                                                      sampling_metadata)
 

vllm/model_executor/models/registry.py

@@ -110,6 +110,7 @@ _TEXT_GENERATION_MODELS = {
     "Phi3ForCausalLM": ("phi3", "Phi3ForCausalLM"),
     "Phi3SmallForCausalLM": ("phi3_small", "Phi3SmallForCausalLM"),
     "PhiMoEForCausalLM": ("phimoe", "PhiMoEForCausalLM"),
+    "Phi4FlashForCausalLM": ("phi4flash", "Phi4FlashForCausalLM"),
     "Plamo2ForCausalLM": ("plamo2", "Plamo2ForCausalLM"),
     "QWenLMHeadModel": ("qwen", "QWenLMHeadModel"),
     "Qwen2ForCausalLM": ("qwen2", "Qwen2ForCausalLM"),

vllm/platforms/cuda.py

@@ -316,6 +316,10 @@ class CudaPlatformBase(Platform):
             logger.info("Using DualChunkFlashAttention backend.")
             return ("vllm.attention.backends.dual_chunk_flash_attn."
                     "DualChunkFlashAttentionBackend")
+        elif selected_backend == _Backend.DIFFERENTIAL_FLASH_ATTN:
+            logger.info("Using DifferentialFlashAttention backend.")
+            return ("vllm.attention.backends.differential_flash_attn."
+                    "DifferentialFlashAttentionBackend")
         elif selected_backend == _Backend.FLASH_ATTN:
             pass
         elif selected_backend:

vllm/platforms/interface.py

@@ -60,6 +60,7 @@ class _Backend(enum.Enum):
     IPEX = enum.auto()
     BLOCK_SPARSE_FLASH_ATTN = enum.auto()
     DUAL_CHUNK_FLASH_ATTN = enum.auto()
+    DIFFERENTIAL_FLASH_ATTN = enum.auto()
     NO_ATTENTION = enum.auto()
     FLEX_ATTENTION = enum.auto()
 

vllm/utils/__init__.py

@@ -2890,6 +2890,7 @@ def get_mp_context():
 def bind_kv_cache(
     ctx: dict[str, Any],
     kv_cache: list[list[torch.Tensor]],  # [virtual_engine][layer_index]
+    shared_kv_cache_layers: Optional[dict[str, str]] = None
 ) -> None:
     # Bind the kv_cache tensor to Attention modules, similar to
     # ctx[layer_name].kv_cache[ve]=kv_cache[ve][extract_layer_index(layer_name)]
@@ -2901,12 +2902,17 @@ def bind_kv_cache(
     #    attention of the same layer (e.g., bart's decoder.layers.1.self_attn
     #    and decoder.layers.1.encoder_attn) is mapped to the same kv cache
     #    tensor
+    # 5. Some models have attention layers that share kv cache with previous
+    #    layers, this is specified through shared_kv_cache_layers
+    if shared_kv_cache_layers is None:
+        shared_kv_cache_layers = {}
     from vllm.attention import AttentionType
     from vllm.model_executor.models.utils import extract_layer_index
     layer_need_kv_cache = [
         layer_name for layer_name in ctx
         if (hasattr(ctx[layer_name], 'attn_type') and ctx[layer_name].attn_type
-            in (AttentionType.DECODER, AttentionType.ENCODER_DECODER))
+            in (AttentionType.DECODER, AttentionType.ENCODER_DECODER)) \
+                and ctx[layer_name].kv_sharing_target_layer_name is None
     ]
     layer_index_sorted = sorted(
         set(
@@ -2919,6 +2925,12 @@ def bind_kv_cache(
         assert len(forward_ctx.kv_cache) == len(kv_cache)
         for ve, ve_kv_cache in enumerate(kv_cache):
             forward_ctx.kv_cache[ve] = ve_kv_cache[kv_cache_idx]
+    if shared_kv_cache_layers is not None:
+        for layer_name, target_layer_name in shared_kv_cache_layers.items():
+            assert extract_layer_index(target_layer_name) < \
+               extract_layer_index(layer_name), \
+                   "v0 doesn't support interleaving kv sharing"
+            ctx[layer_name].kv_cache = ctx[target_layer_name].kv_cache
 
 
 def run_method(obj: Any, method: Union[str, bytes, Callable], args: tuple[Any],