[NVIDIA] Add support for cudnn fp4 gemm via flashinfer (#26107)

Signed-off-by: kaixih <kaixih@nvidia.com>
Signed-off-by: mgoin <mgoin64@gmail.com>
Co-authored-by: mgoin <mgoin64@gmail.com>
This commit is contained in:
Kaixi Hou
2025-10-15 13:53:00 -04:00
committed by GitHub
co-authored by mgoin
parent a1063628a4
commit de92d916fe
3 changed files with 57 additions and 38 deletions
@@ -926,22 +926,26 @@ class ModelOptNvFp4LinearMethod(LinearMethodBase):
def __init__(self, quant_config: ModelOptNvFp4Config) -> None:
self.quant_config = quant_config
if envs.VLLM_USE_TRTLLM_FP4_GEMM:
assert has_flashinfer(), "TRTLLM FP4 GEMM requires FlashInfer"
self.backend = "flashinfer-trtllm"
elif has_flashinfer():
self.backend = "flashinfer-cutlass"
elif cutlass_fp4_supported():
self.backend = "cutlass"
elif is_fp4_marlin_supported():
self.backend = "marlin"
else:
self.backend = "none"
if envs.VLLM_NVFP4_GEMM_BACKEND is None:
if has_flashinfer():
self.backend = "flashinfer-cutlass"
elif cutlass_fp4_supported():
self.backend = "cutlass"
elif is_fp4_marlin_supported():
self.backend = "marlin"
elif envs.VLLM_NVFP4_GEMM_BACKEND.startswith("flashinfer-"):
self.backend = envs.VLLM_NVFP4_GEMM_BACKEND
assert has_flashinfer(), f"FlashInfer is required for {self.backend}"
if self.backend == "none":
raise ValueError(
"Current platform does not support NVFP4"
" quantization. Please use Blackwell and"
" above."
"No valid NVFP4 GEMM backend found. "
"Please check your platform capability."
)
logger.info_once(f"Using {self.backend} for NVFP4 GEMM")
def create_weights(
self,
layer: torch.nn.Module,
@@ -1109,11 +1113,11 @@ class ModelOptNvFp4LinearMethod(LinearMethodBase):
layer.alpha,
output_dtype,
)
if self.backend == "flashinfer-trtllm":
out = flashinfer_scaled_fp4_mm(*mm_args, backend="trtllm")
elif self.backend == "flashinfer-cutlass":
out = flashinfer_scaled_fp4_mm(*mm_args, backend="cutlass")
if self.backend.startswith("flashinfer-"):
backend_name = self.backend[len("flashinfer-") :]
out = flashinfer_scaled_fp4_mm(*mm_args, backend=backend_name)
else:
assert self.backend == "cutlass"
out = cutlass_scaled_fp4_mm(*mm_args)
if bias is not None: