[TRTLLM-7735][feat] Attention NVFP4 out support for torch compile

cpp/tensorrt_llm/nanobind/thop/bindings.cpp

@@ -39,9 +39,9 @@ void initBindings(nb::module_& m)
     m.def("attention", &torch_ext::attention,
         // Parameters with default values using std::nullopt for optional arguments
         nb::arg("q"), nb::arg("k") = std::nullopt, nb::arg("v") = std::nullopt, nb::arg("output"),
-        nb::arg("output_sf") = std::nullopt, nb::arg("out_dtype") = std::nullopt, nb::arg("workspace_") = std::nullopt,
-        nb::arg("sequence_length"), nb::arg("host_past_key_value_lengths"), nb::arg("host_total_kv_lens"),
-        nb::arg("context_lengths"), nb::arg("host_context_lengths"), nb::arg("host_request_types"),
+        nb::arg("output_sf") = std::nullopt, nb::arg("workspace_") = std::nullopt, nb::arg("sequence_length"),
+        nb::arg("host_past_key_value_lengths"), nb::arg("host_total_kv_lens"), nb::arg("context_lengths"),
+        nb::arg("host_context_lengths"), nb::arg("host_request_types"),
         nb::arg("kv_cache_block_offsets") = std::nullopt, nb::arg("host_kv_cache_block_offsets") = std::nullopt,
         nb::arg("host_kv_cache_pool_pointers") = std::nullopt, nb::arg("host_kv_cache_pool_mapping") = std::nullopt,
         nb::arg("cache_indirection") = std::nullopt, nb::arg("kv_scale_orig_quant") = std::nullopt,

cpp/tensorrt_llm/pybind/thop/bindings.cpp

@@ -39,9 +39,9 @@ void initBindings(pybind11::module_& m)
     m.def("attention", &torch_ext::attention,
         // Parameters with default values using std::nullopt for optional arguments
         py::arg("q"), py::arg("k") = std::nullopt, py::arg("v") = std::nullopt, py::arg("output"),
-        py::arg("output_sf") = std::nullopt, py::arg("out_dtype") = std::nullopt, py::arg("workspace_") = std::nullopt,
-        py::arg("sequence_length"), py::arg("host_past_key_value_lengths"), py::arg("host_total_kv_lens"),
-        py::arg("context_lengths"), py::arg("host_context_lengths"), py::arg("host_request_types"),
+        py::arg("output_sf") = std::nullopt, py::arg("workspace_") = std::nullopt, py::arg("sequence_length"),
+        py::arg("host_past_key_value_lengths"), py::arg("host_total_kv_lens"), py::arg("context_lengths"),
+        py::arg("host_context_lengths"), py::arg("host_request_types"),
         py::arg("kv_cache_block_offsets") = std::nullopt, py::arg("host_kv_cache_block_offsets") = std::nullopt,
         py::arg("host_kv_cache_pool_pointers") = std::nullopt, py::arg("host_kv_cache_pool_mapping") = std::nullopt,
         py::arg("cache_indirection") = std::nullopt, py::arg("kv_scale_orig_quant") = std::nullopt,

cpp/tensorrt_llm/thop/attentionOp.cpp

@@ -603,23 +603,22 @@ using torch_ext::trtllm::attention::Runner;
 using torch_ext::trtllm::attention::AttentionInputType;
 
 void attention(torch::Tensor q, std::optional<torch::Tensor> k, std::optional<torch::Tensor> v, torch::Tensor& output,
-    std::optional<torch::Tensor> output_sf, std::optional<torch::ScalarType> out_dtype,
-    std::optional<torch::Tensor> workspace_, torch::Tensor sequence_length, torch::Tensor host_past_key_value_lengths,
-    torch::Tensor host_total_kv_lens, torch::Tensor context_lengths, torch::Tensor host_context_lengths,
-    torch::Tensor host_request_types, std::optional<torch::Tensor> kv_cache_block_offsets,
-    std::optional<torch::Tensor> host_kv_cache_block_offsets, std::optional<torch::Tensor> host_kv_cache_pool_pointers,
-    std::optional<torch::Tensor> host_kv_cache_pool_mapping, std::optional<torch::Tensor> cache_indirection,
-    std::optional<torch::Tensor> kv_scale_orig_quant, std::optional<torch::Tensor> kv_scale_quant_orig,
-    std::optional<torch::Tensor> out_scale, std::optional<torch::Tensor> rotary_inv_freq,
-    std::optional<torch::Tensor> rotary_cos_sin, std::optional<torch::Tensor> latent_cache,
-    std::optional<torch::Tensor> q_pe, std::optional<torch::Tensor> block_ids_per_seq,
-    std::optional<torch::Tensor> attention_sinks, bool const is_fused_qkv, bool const update_kv_cache,
-    int64_t const predicted_tokens_per_seq, int64_t const layer_idx, int64_t const num_heads,
-    int64_t const num_kv_heads, int64_t const head_size, std::optional<int64_t> const tokens_per_block,
-    int64_t const max_num_requests, int64_t const max_context_length, int64_t const attention_window_size,
-    int64_t const sink_token_length, int64_t const beam_width, int64_t const mask_type, int64_t const quant_mode,
-    double const q_scaling, int64_t const position_embedding_type, int64_t const rotary_embedding_dim,
-    double const rotary_embedding_base, int64_t const rotary_embedding_scale_type,
+    std::optional<torch::Tensor> output_sf, std::optional<torch::Tensor> workspace_, torch::Tensor sequence_length,
+    torch::Tensor host_past_key_value_lengths, torch::Tensor host_total_kv_lens, torch::Tensor context_lengths,
+    torch::Tensor host_context_lengths, torch::Tensor host_request_types,
+    std::optional<torch::Tensor> kv_cache_block_offsets, std::optional<torch::Tensor> host_kv_cache_block_offsets,
+    std::optional<torch::Tensor> host_kv_cache_pool_pointers, std::optional<torch::Tensor> host_kv_cache_pool_mapping,
+    std::optional<torch::Tensor> cache_indirection, std::optional<torch::Tensor> kv_scale_orig_quant,
+    std::optional<torch::Tensor> kv_scale_quant_orig, std::optional<torch::Tensor> out_scale,
+    std::optional<torch::Tensor> rotary_inv_freq, std::optional<torch::Tensor> rotary_cos_sin,
+    std::optional<torch::Tensor> latent_cache, std::optional<torch::Tensor> q_pe,
+    std::optional<torch::Tensor> block_ids_per_seq, std::optional<torch::Tensor> attention_sinks,
+    bool const is_fused_qkv, bool const update_kv_cache, int64_t const predicted_tokens_per_seq,
+    int64_t const layer_idx, int64_t const num_heads, int64_t const num_kv_heads, int64_t const head_size,
+    std::optional<int64_t> const tokens_per_block, int64_t const max_num_requests, int64_t const max_context_length,
+    int64_t const attention_window_size, int64_t const sink_token_length, int64_t const beam_width,
+    int64_t const mask_type, int64_t const quant_mode, double const q_scaling, int64_t const position_embedding_type,
+    int64_t const rotary_embedding_dim, double const rotary_embedding_base, int64_t const rotary_embedding_scale_type,
     std::vector<double> rotary_embedding_scales, std::vector<int64_t> rotary_embedding_max_position_info,
     bool const use_paged_context_fmha, std::optional<int64_t> attention_input_type, bool is_mla_enable,
     std::optional<int64_t> chunked_prefill_buffer_batch_size, std::optional<int64_t> q_lora_rank,
@@ -658,8 +657,10 @@ void attention(torch::Tensor q, std::optional<torch::Tensor> k, std::optional<to
     }
 
     auto const dtype = tensorrt_llm::runtime::TorchUtils::dataType(qkv_or_q.scalar_type());
-    bool const is_fp8_out = out_dtype.has_value() && out_dtype.value() == torch::kFloat8_e4m3fn;
-    bool const is_fp4_out = out_dtype.has_value() && out_dtype.value() == torch::kUInt8;
+    auto const out_dtype = output.scalar_type();
+    bool const is_fp8_out = out_dtype == torch::kFloat8_e4m3fn;
+    // Torch does not support native nvfp4 type.
+    bool const is_fp4_out = out_dtype == torch::kUInt8;
 
     RunnerPtr runner;
     if (dtype == nvinfer1::DataType::kHALF)
@@ -674,13 +675,13 @@ void attention(torch::Tensor q, std::optional<torch::Tensor> k, std::optional<to
         }
         else
         {
-            TLLM_CHECK(!out_dtype.has_value() || out_dtype.value() == torch::kFloat16);
+            TLLM_CHECK(out_dtype == torch::kFloat16);
             runner = std::make_shared<Runner<half>>();
         }
     }
     else if (dtype == nvinfer1::DataType::kFLOAT)
     {
-        TLLM_CHECK(!out_dtype.has_value() || out_dtype.value() == torch::kFloat32);
+        TLLM_CHECK(out_dtype == torch::kFloat32);
         runner = std::make_shared<Runner<float>>();
     }
 #ifdef ENABLE_BF16
@@ -696,7 +697,7 @@ void attention(torch::Tensor q, std::optional<torch::Tensor> k, std::optional<to
         }
         else
         {
-            TLLM_CHECK(!out_dtype.has_value() || out_dtype.value() == torch::kBFloat16);
+            TLLM_CHECK(out_dtype == torch::kBFloat16);
             runner = std::make_shared<Runner<__nv_bfloat16>>();
         }
     }

cpp/tensorrt_llm/thop/attentionOp.h

@@ -39,23 +39,22 @@ namespace torch_ext
  * - Speculative decoding
  */
 void attention(torch::Tensor q, std::optional<torch::Tensor> k, std::optional<torch::Tensor> v, torch::Tensor& output,
-    std::optional<torch::Tensor> output_sf, std::optional<torch::ScalarType> out_dtype,
-    std::optional<torch::Tensor> workspace_, torch::Tensor sequence_length, torch::Tensor host_past_key_value_lengths,
-    torch::Tensor host_total_kv_lens, torch::Tensor context_lengths, torch::Tensor host_context_lengths,
-    torch::Tensor host_request_types, std::optional<torch::Tensor> kv_cache_block_offsets,
-    std::optional<torch::Tensor> host_kv_cache_block_offsets, std::optional<torch::Tensor> host_kv_cache_pool_pointers,
-    std::optional<torch::Tensor> host_kv_cache_pool_mapping, std::optional<torch::Tensor> cache_indirection,
-    std::optional<torch::Tensor> kv_scale_orig_quant, std::optional<torch::Tensor> kv_scale_quant_orig,
-    std::optional<torch::Tensor> out_scale, std::optional<torch::Tensor> rotary_inv_freq,
-    std::optional<torch::Tensor> rotary_cos_sin, std::optional<torch::Tensor> latent_cache,
-    std::optional<torch::Tensor> q_pe, std::optional<torch::Tensor> block_ids_per_seq,
-    std::optional<torch::Tensor> attention_sinks, bool const is_fused_qkv, bool const update_kv_cache,
-    int64_t const predicted_tokens_per_seq, int64_t const layer_idx, int64_t const num_heads,
-    int64_t const num_kv_heads, int64_t const head_size, std::optional<int64_t> const tokens_per_block,
-    int64_t const max_num_requests, int64_t const max_context_length, int64_t const attention_window_size,
-    int64_t const sink_token_length, int64_t const beam_width, int64_t const mask_type, int64_t const quant_mode,
-    double const q_scaling, int64_t const position_embedding_type, int64_t const rotary_embedding_dim,
-    double const rotary_embedding_base, int64_t const rotary_embedding_scale_type,
+    std::optional<torch::Tensor> output_sf, std::optional<torch::Tensor> workspace_, torch::Tensor sequence_length,
+    torch::Tensor host_past_key_value_lengths, torch::Tensor host_total_kv_lens, torch::Tensor context_lengths,
+    torch::Tensor host_context_lengths, torch::Tensor host_request_types,
+    std::optional<torch::Tensor> kv_cache_block_offsets, std::optional<torch::Tensor> host_kv_cache_block_offsets,
+    std::optional<torch::Tensor> host_kv_cache_pool_pointers, std::optional<torch::Tensor> host_kv_cache_pool_mapping,
+    std::optional<torch::Tensor> cache_indirection, std::optional<torch::Tensor> kv_scale_orig_quant,
+    std::optional<torch::Tensor> kv_scale_quant_orig, std::optional<torch::Tensor> out_scale,
+    std::optional<torch::Tensor> rotary_inv_freq, std::optional<torch::Tensor> rotary_cos_sin,
+    std::optional<torch::Tensor> latent_cache, std::optional<torch::Tensor> q_pe,
+    std::optional<torch::Tensor> block_ids_per_seq, std::optional<torch::Tensor> attention_sinks,
+    bool const is_fused_qkv, bool const update_kv_cache, int64_t const predicted_tokens_per_seq,
+    int64_t const layer_idx, int64_t const num_heads, int64_t const num_kv_heads, int64_t const head_size,
+    std::optional<int64_t> const tokens_per_block, int64_t const max_num_requests, int64_t const max_context_length,
+    int64_t const attention_window_size, int64_t const sink_token_length, int64_t const beam_width,
+    int64_t const mask_type, int64_t const quant_mode, double const q_scaling, int64_t const position_embedding_type,
+    int64_t const rotary_embedding_dim, double const rotary_embedding_base, int64_t const rotary_embedding_scale_type,
     std::vector<double> rotary_embedding_scales, std::vector<int64_t> rotary_embedding_max_position_info,
     bool const use_paged_context_fmha, std::optional<int64_t> attention_input_type, bool is_mla_enable,
     std::optional<int64_t> chunked_prefill_buffer_batch_size, std::optional<int64_t> q_lora_rank,

tensorrt_llm/_torch/attention_backend/interface.py

@@ -705,9 +705,13 @@ def support_fused_qkv(cls) -> bool:
     def support_mla(cls) -> bool:
         return False
 
-    @classmethod
-    def support_nvfp4_output(cls) -> bool:
-        return False
+    def create_output(self, q: torch.Tensor, **kwargs) -> List[torch.Tensor]:
+        """
+        Create the output tensors for the attention operation.
+        """
+        num_tokens = q.shape[0]
+        hidden_size = self.num_heads * self.head_dim
+        return [q.new_empty([num_tokens, hidden_size], dtype=q.dtype)]
 
 
 @dataclass(kw_only=True, unsafe_hash=True)