[ROCM] DSfp4 mla projection gemms weight dynamic quantization (#32238)

Signed-off-by: Aleksandr Malyshev <maleksan@amd.com>
Co-authored-by: Aleksandr Malyshev <maleksan@amd.com>

vllm/_aiter_ops.py

@@ -837,6 +837,7 @@ class rocm_aiter_ops:
     _TRITON_UNIFIED_ATTN_ENABLED = envs.VLLM_ROCM_USE_AITER_UNIFIED_ATTENTION
     # TODO: Consolidate under _LINEAR_ENABLED
     _FP8BMM_ENABLED = envs.VLLM_ROCM_USE_AITER_FP8BMM
+    _FP4BMM_ENABLED = envs.VLLM_ROCM_USE_AITER_FP4BMM
     # TODO: Consolidate under _LINEAR_ENABLED
     _FP4_GEMM_DYNAMIC_QUANT_ASM = envs.VLLM_ROCM_USE_AITER_FP4_ASM_GEMM
     # TODO: Consolidate under VLLM_ROCM_USE_AITER_ROPE
@@ -863,6 +864,7 @@ class rocm_aiter_ops:
         cls._SHUFFLE_KV_CACHE_ENABLED = envs.VLLM_ROCM_SHUFFLE_KV_CACHE_LAYOUT
         cls._TRITON_UNIFIED_ATTN_ENABLED = envs.VLLM_ROCM_USE_AITER_UNIFIED_ATTENTION
         cls._FP8BMM_ENABLED = envs.VLLM_ROCM_USE_AITER_FP8BMM
+        cls._FP4BMM_ENABLED = envs.VLLM_ROCM_USE_AITER_FP4BMM
         cls._FP4_GEMM_DYNAMIC_QUANT_ASM = envs.VLLM_ROCM_USE_AITER_FP4_ASM_GEMM
         cls._TRITON_ROTARY_EMBED = envs.VLLM_ROCM_USE_AITER_TRITON_ROPE
         cls._MOE_SHARED_EXPERTS_ENABLED = envs.VLLM_ROCM_USE_AITER_FUSION_SHARED_EXPERTS
@@ -923,6 +925,11 @@ class rocm_aiter_ops:
     def is_fp8bmm_enabled(cls) -> bool:
         return cls._AITER_ENABLED and cls._FP8BMM_ENABLED
 
+    @classmethod
+    @if_aiter_supported
+    def is_fp4bmm_enabled(cls) -> bool:
+        return cls._AITER_ENABLED and cls._FP4BMM_ENABLED
+
     @classmethod
     @if_aiter_supported
     def is_asm_fp4_gemm_dynamic_quant_enabled(cls) -> bool:
@@ -1403,6 +1410,29 @@ class rocm_aiter_ops:
         query = query.view(query_shape)
         key = key.view(key_shape)
 
+    @staticmethod
+    def batched_gemm_a16wfp4(
+        X: torch.Tensor,
+        W: torch.Tensor,
+        w_scale: torch.Tensor,
+        Y: torch.Tensor,
+        transpose_bm: bool | None = False,
+        prequant: bool | None = False,
+        y_scale: torch.Tensor | None = None,
+    ) -> torch.Tensor:
+        # ruff: noqa: E501 # isort: skip
+        from aiter.ops.triton.batched_gemm_a16wfp4 import batched_gemm_a16wfp4
+
+        return batched_gemm_a16wfp4(
+            X,
+            W,
+            w_scale,
+            y=Y,
+            transpose_bm=transpose_bm,
+            prequant=prequant,
+            y_scale=y_scale,
+        )
+
     @staticmethod
     def triton_fp8_bmm(
         X: torch.Tensor,

vllm/envs.py

@@ -121,6 +121,7 @@ if TYPE_CHECKING:
     VLLM_ROCM_USE_AITER_FP4_ASM_GEMM: bool = False
     VLLM_ROCM_USE_AITER_TRITON_ROPE: bool = False
     VLLM_ROCM_USE_AITER_FP8BMM: bool = True
+    VLLM_ROCM_USE_AITER_FP4BMM: bool = True
     VLLM_ROCM_USE_AITER_UNIFIED_ATTENTION: bool = False
     VLLM_ROCM_USE_AITER_FUSION_SHARED_EXPERTS: bool = False
     VLLM_ROCM_USE_AITER_TRITON_GEMM: bool = True
@@ -991,6 +992,11 @@ environment_variables: dict[str, Callable[[], Any]] = {
     "VLLM_ROCM_USE_AITER_FP8BMM": lambda: (
         os.getenv("VLLM_ROCM_USE_AITER_FP8BMM", "True").lower() in ("true", "1")
     ),
+    # Whether to use aiter triton fp4 bmm kernel
+    # By default is enabled.
+    "VLLM_ROCM_USE_AITER_FP4BMM": lambda: (
+        os.getenv("VLLM_ROCM_USE_AITER_FP4BMM", "True").lower() in ("true", "1")
+    ),
     # Use AITER triton unified attention for V1 attention
     "VLLM_ROCM_USE_AITER_UNIFIED_ATTENTION": lambda: (
         os.getenv("VLLM_ROCM_USE_AITER_UNIFIED_ATTENTION", "False").lower()

vllm/model_executor/layers/attention/mla_attention.py

@@ -1183,6 +1183,12 @@ class MLACommonBaseImpl(MLAAttentionImpl[A], Generic[A]):
         self.q_pad_num_heads = q_pad_num_heads
         self.is_aiter_triton_fp8_bmm_enabled = rocm_aiter_ops.is_fp8bmm_enabled()
 
+        # If kv_b_proj_weight is unquantized, quantize it to mxfp4 if supported
+        self.is_aiter_triton_fp4_bmm_enabled = (
+            rocm_aiter_ops.is_fp4bmm_enabled()
+            and self.kv_b_proj.weight.dtype == torch.bfloat16
+        )
+
     def process_weights_after_loading(self, act_dtype: torch.dtype):
         # we currently do not have quantized bmm's which are needed for
         # `W_UV` and `W_UK_T`, we just store fp16/bf16 copies and perform
@@ -1211,7 +1217,21 @@ class MLACommonBaseImpl(MLAAttentionImpl[A], Generic[A]):
             [self.qk_nope_head_dim, self.v_head_dim], dim=-1
         )
 
-        if self.is_aiter_triton_fp8_bmm_enabled:
+        # If kv_b_proj_weight is unquantized, quantize it to mxfp4 if supported
+        if self.is_aiter_triton_fp4_bmm_enabled:
+            from vllm.model_executor.layers.quantization.quark.utils import (
+                quark_quantize_weight_to_mxfp4,
+            )
+
+            self.W_K, self.W_K_scale = quark_quantize_weight_to_mxfp4(W_UK)
+            # Convert from (L, N, P) to (N, L, P)
+            self.W_K = self.W_K.transpose(0, 1)
+            self.W_K_scale = self.W_K_scale.transpose(0, 1)
+
+            self.W_V, self.W_V_scale = quark_quantize_weight_to_mxfp4(
+                W_UV.permute(1, 2, 0)
+            )
+        elif self.is_aiter_triton_fp8_bmm_enabled:
             W_K = W_UK.transpose(0, 1)  # 16 512 128
             W_V = W_UV.permute(1, 2, 0)  # 16 128 512
             self.W_K, self.W_K_scale = dynamic_per_batched_tensor_quant(
@@ -1261,16 +1281,26 @@ class MLACommonBaseImpl(MLAAttentionImpl[A], Generic[A]):
     def _v_up_proj(self, x: torch.Tensor, out: torch.Tensor):
         # Convert from (B, N, L) to (N, B, L)
         x = x.view(-1, self.num_heads, self.kv_lora_rank).transpose(0, 1)
-
-        if self.is_aiter_triton_fp8_bmm_enabled:
-            out = out.view(-1, self.num_heads, self.v_head_dim)
+        out = out.view(-1, self.num_heads, self.v_head_dim)
+        if self.is_aiter_triton_fp4_bmm_enabled:
+            out = rocm_aiter_ops.batched_gemm_a16wfp4(
+                x,
+                self.W_V,
+                self.W_V_scale,
+                out,
+                transpose_bm=True,
+                prequant=True,
+                y_scale=None,
+            )
+            x = out.view(-1, self.num_heads * self.v_head_dim)
+        elif self.is_aiter_triton_fp8_bmm_enabled:
             # Multiply + Transpose (N, B, L) x (N, L, V)->(N, B, V)->(B, N, V)
             x = rocm_aiter_ops.triton_fp8_bmm(
                 x, self.W_V, self.W_V_scale, group_size=128, transpose_bm=True, YQ=out
             )
         else:
             # Convert from (B, N * V) to (N, B, V)
-            out = out.view(-1, self.num_heads, self.v_head_dim).transpose(0, 1)
+            out = out.transpose(0, 1)
 
             # Multiply (N, B, L) x (N, L, V) -> (N, B, V)
             torch.bmm(x, self.W_UV, out=out)  # Reuse "out" to make it "hot"
@@ -1579,80 +1609,6 @@ class MLACommonImpl(MLACommonBaseImpl[M], Generic[M]):
         # Convert from (q_len, num_heads) to (num_heads, q_len)
         return attn_out, lse.transpose(0, 1).contiguous()
 
-    def process_weights_after_loading(self, act_dtype: torch.dtype):
-        # we currently do not have quantized bmm's which are needed for
-        # `W_UV` and `W_UK_T`, we just store fp16/bf16 copies and perform
-        # the bmm's in 16-bit, the extra memory overhead of this is fairly low
-        kv_b_proj_weight = get_and_maybe_dequant_weights(
-            self.kv_b_proj, out_dtype=act_dtype
-        ).T
-        assert kv_b_proj_weight.shape == (
-            self.kv_lora_rank,
-            self.num_heads * (self.qk_nope_head_dim + self.v_head_dim),
-        ), (
-            f"{kv_b_proj_weight.shape=}, "
-            f"{self.kv_lora_rank=}, "
-            f"{self.num_heads=}, "
-            f"{self.qk_nope_head_dim=}, "
-            f"{self.v_head_dim=}"
-        )
-        kv_b_proj_weight = kv_b_proj_weight.view(
-            self.kv_lora_rank,
-            self.num_heads,
-            self.qk_nope_head_dim + self.v_head_dim,
-        )
-
-        W_UK, W_UV = kv_b_proj_weight.split(
-            [self.qk_nope_head_dim, self.v_head_dim], dim=-1
-        )
-
-        if self.is_aiter_triton_fp8_bmm_enabled:
-            W_K = W_UK.transpose(0, 1)  # 16 512 128
-            W_V = W_UV.permute(1, 2, 0)  # 16 128 512
-            self.W_K, self.W_K_scale = dynamic_per_batched_tensor_quant(
-                W_K, dtype=current_platform.fp8_dtype()
-            )
-            self.W_V, self.W_V_scale = dynamic_per_batched_tensor_quant(
-                W_V, dtype=current_platform.fp8_dtype()
-            )
-
-            # The kernel operates on non-padded inputs. Hence, pre-compiling
-            # triton kernel to avoid runtime compilation for unseen batch sizes
-            # Pre-compile for batch sizes 1 to 1024 to cover most use-cases.
-            # On DS-R1, this step adds roughly 50s to the model loading time.
-            max_batch_size = 1024  # [ToDo] Find the optimal upper limit
-            pre_compilation_list = list(range(1, max_batch_size + 1))
-            if is_global_first_rank():
-                pre_compilation_list = tqdm(
-                    pre_compilation_list,
-                    desc="[Aiter Triton] Pre-compiling fp8 BMM kernel",
-                    total=max_batch_size,
-                )
-
-            for m in pre_compilation_list:
-                x = torch.empty(
-                    (self.W_K.shape[0], m, self.W_K.shape[2]),
-                    dtype=torch.bfloat16,
-                    device=self.W_K.device,
-                )
-                rocm_aiter_ops.triton_fp8_bmm(
-                    x, self.W_K, self.W_K_scale, group_size=128, transpose_bm=True
-                )
-
-                x = torch.empty(
-                    (self.W_V.shape[0], m, self.W_V.shape[2]),
-                    dtype=torch.bfloat16,
-                    device=self.W_V.device,
-                )
-                rocm_aiter_ops.triton_fp8_bmm(
-                    x, self.W_V, self.W_V_scale, group_size=128, transpose_bm=True
-                )
-        else:
-            # Convert from (L, N, V) to (N, L, V)
-            self.W_UV = W_UV.transpose(0, 1)
-            # Convert from (L, N, P) to (N, P, L)
-            self.W_UK_T = W_UK.permute(1, 2, 0)
-
     def _concat_k_nope_k_pe(
         self, k_nope: torch.Tensor, k_pe: torch.Tensor
     ) -> torch.Tensor:
@@ -2033,7 +1989,18 @@ class MLACommonImpl(MLACommonBaseImpl[M], Generic[M]):
                 decode_pe_padded.copy_(decode_q_pe)
                 decode_q_pe = decode_pe_padded
 
-            if self.is_aiter_triton_fp8_bmm_enabled:
+            if self.is_aiter_triton_fp4_bmm_enabled:
+                from aiter.ops.triton.batched_gemm_a16wfp4 import batched_gemm_a16wfp4
+
+                decode_ql_nope = batched_gemm_a16wfp4(
+                    decode_q_nope,
+                    self.W_K,
+                    self.W_K_scale,
+                    transpose_bm=True,
+                    prequant=True,
+                    y_scale=layer._q_scale if fp8_attention else None,
+                )
+            elif self.is_aiter_triton_fp8_bmm_enabled:
                 # Multiply+Transpose (N, B, P)x(N, P, L)->(N, B, L)->(B, N, L)
                 decode_ql_nope = rocm_aiter_ops.triton_fp8_bmm(
                     decode_q_nope,

vllm/model_executor/layers/quantization/quark/utils.py

@@ -6,6 +6,7 @@ from types import MappingProxyType
 from typing import Any
 
 import regex as re
+import torch
 
 
 def deep_compare(dict1: Any, dict2: Any) -> bool:
@@ -103,3 +104,16 @@ def _is_equal_or_regex_match(
     elif target == value:
         return True
     return False
+
+
+# utility for tensor dims > 2 cases
+def quark_quantize_weight_to_mxfp4(w: torch.Tensor):
+    assert w.dtype == torch.bfloat16, (
+        "Quark dynamic quantization is supported only for fp16 weights and only to MXF4"
+    )
+
+    from aiter.ops.triton.quant import dynamic_mxfp4_quant
+
+    *dims, d = w.shape
+    w, w_scales = dynamic_mxfp4_quant(w.reshape(-1, d))
+    return w.view(*dims, d // 2), w_scales.view(*dims, d // 32)