[NVIDIA] Support Cutlass w8a8 FP8 for Blackwell Geforce GPUs (sm120) (#17280)

Signed-off-by: kaln27 <liaojuncheng123@foxmail.com>
Co-authored-by: mgoin <mgoin64@gmail.com>
This commit is contained in:
Joonchen Liau
2025-07-02 20:47:19 +08:00
committed by GitHub
parent 0c600b9ab6
commit 9e5552aa13
7 changed files with 238 additions and 1 deletions

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@@ -144,4 +144,65 @@ struct cutlass_3x_gemm_sm100 {
Shape<int, int, int, int>, CollectiveMainloop, CollectiveEpilogue, void>;
};
template <typename ElementAB_, typename ElementD_,
template <typename, typename, typename> typename Epilogue_,
typename TileShape, typename ClusterShape, typename KernelSchedule,
typename EpilogueSchedule>
struct cutlass_3x_gemm_sm120 {
using ElementAB = ElementAB_;
using LayoutA = cutlass::layout::RowMajor;
static constexpr int AlignmentA =
128 / cutlass::sizeof_bits<ElementAB>::value;
using LayoutB = cutlass::layout::ColumnMajor;
static constexpr int AlignmentB =
128 / cutlass::sizeof_bits<ElementAB>::value;
using ElementC = void;
using LayoutC = cutlass::layout::RowMajor;
static constexpr int AlignmentC =
128 / cutlass::sizeof_bits<ElementD_>::value;
using ElementD = ElementD_;
using LayoutD = cutlass::layout::RowMajor;
static constexpr int AlignmentD = AlignmentC;
using ElementAcc =
typename std::conditional<std::is_same_v<ElementAB, int8_t>, int32_t,
float>::type;
using Epilogue = Epilogue_<ElementAcc, ElementD, TileShape>;
// MMA type
using ElementAccumulator = float;
// Epilogue types
using ElementBias = cutlass::half_t;
using ElementCompute = float;
using ElementAux = ElementD;
using LayoutAux = LayoutD;
using ElementAmax = float;
using EVTCompute = typename Epilogue::EVTCompute;
using CollectiveEpilogue =
typename cutlass::epilogue::collective::CollectiveBuilder<
cutlass::arch::Sm120, cutlass::arch::OpClassTensorOp, TileShape,
ClusterShape, cutlass::epilogue::collective::EpilogueTileAuto,
ElementAccumulator, ElementCompute, ElementC, LayoutC, AlignmentC,
ElementD, LayoutD, AlignmentD, EpilogueSchedule,
EVTCompute>::CollectiveOp;
using CollectiveMainloop =
typename cutlass::gemm::collective::CollectiveBuilder<
cutlass::arch::Sm120, cutlass::arch::OpClassTensorOp, ElementAB,
LayoutA, AlignmentA, ElementAB, LayoutB, AlignmentB,
ElementAccumulator, TileShape, ClusterShape,
cutlass::gemm::collective::StageCountAutoCarveout<static_cast<int>(
sizeof(typename CollectiveEpilogue::SharedStorage))>,
KernelSchedule>::CollectiveOp;
using GemmKernel = cutlass::gemm::kernel::GemmUniversal<
Shape<int, int, int, int>, CollectiveMainloop, CollectiveEpilogue, void>;
};
} // namespace vllm

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@@ -36,6 +36,12 @@ void cutlass_scaled_mm_sm100_fp8(torch::Tensor& out, torch::Tensor const& a,
torch::Tensor const& b_scales,
std::optional<torch::Tensor> const& bias);
void cutlass_scaled_mm_sm120_fp8(torch::Tensor& out, torch::Tensor const& a,
torch::Tensor const& b,
torch::Tensor const& a_scales,
torch::Tensor const& b_scales,
std::optional<torch::Tensor> const& bias);
void cutlass_scaled_mm_blockwise_sm100_fp8(torch::Tensor& out,
torch::Tensor const& a,
torch::Tensor const& b,

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@@ -0,0 +1,24 @@
#include "scaled_mm_kernels.hpp"
#include "scaled_mm_sm120_fp8_dispatch.cuh"
#include "cutlass_extensions/epilogue/scaled_mm_epilogues_c3x.hpp"
namespace vllm {
void cutlass_scaled_mm_sm120_fp8(torch::Tensor& out, torch::Tensor const& a,
torch::Tensor const& b,
torch::Tensor const& a_scales,
torch::Tensor const& b_scales,
std::optional<torch::Tensor> const& bias) {
TORCH_CHECK(a_scales.is_contiguous() && b_scales.is_contiguous());
if (bias) {
TORCH_CHECK(bias->dtype() == out.dtype(),
"currently bias dtype must match output dtype ", out.dtype());
return cutlass_scaled_mm_sm120_fp8_epilogue<c3x::ScaledEpilogueBias>(
out, a, b, a_scales, b_scales, *bias);
} else {
return cutlass_scaled_mm_sm120_fp8_epilogue<c3x::ScaledEpilogue>(
out, a, b, a_scales, b_scales);
}
}
} // namespace vllm

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@@ -0,0 +1,67 @@
#pragma once
#include "scaled_mm.cuh"
#include "cutlass_gemm_caller.cuh"
/**
* This file defines Gemm kernel configurations for SM120 (fp8) based on the
* Gemm shape.
*/
namespace vllm {
using c3x::cutlass_gemm_caller;
template <typename InType, typename OutType,
template <typename, typename, typename> typename Epilogue>
struct sm120_fp8_config_default {
static_assert(std::is_same<InType, cutlass::float_e4m3_t>());
using KernelSchedule = cutlass::gemm::collective::KernelScheduleAuto;
using EpilogueSchedule = cutlass::epilogue::collective::EpilogueScheduleAuto;
using TileShape = Shape<_128, _128, _128>;
using ClusterShape = Shape<_1, _1, _1>; // Only work with Shape<_1, _1, _1>
using Cutlass3xGemm =
cutlass_3x_gemm_sm120<InType, OutType, Epilogue, TileShape, ClusterShape,
KernelSchedule, EpilogueSchedule>;
};
template <typename InType, typename OutType,
template <typename, typename, typename> typename Epilogue,
typename... EpilogueArgs>
inline void cutlass_gemm_sm120_fp8_dispatch(torch::Tensor& out,
torch::Tensor const& a,
torch::Tensor const& b,
EpilogueArgs&&... args) {
static_assert(std::is_same<InType, cutlass::float_e4m3_t>());
TORCH_CHECK(a.dtype() == torch::kFloat8_e4m3fn);
TORCH_CHECK(b.dtype() == torch::kFloat8_e4m3fn);
using Cutlass3xGemmDefault =
typename sm120_fp8_config_default<InType, OutType,
Epilogue>::Cutlass3xGemm;
return cutlass_gemm_caller<Cutlass3xGemmDefault>(
out, a, b, std::forward<EpilogueArgs>(args)...);
}
template <template <typename, typename, typename> typename Epilogue,
typename... EpilogueArgs>
void cutlass_scaled_mm_sm120_fp8_epilogue(torch::Tensor& out,
torch::Tensor const& a,
torch::Tensor const& b,
EpilogueArgs&&... epilogue_args) {
TORCH_CHECK(a.dtype() == torch::kFloat8_e4m3fn);
TORCH_CHECK(b.dtype() == torch::kFloat8_e4m3fn);
if (out.dtype() == torch::kBFloat16) {
return cutlass_gemm_sm120_fp8_dispatch<cutlass::float_e4m3_t,
cutlass::bfloat16_t, Epilogue>(
out, a, b, std::forward<EpilogueArgs>(epilogue_args)...);
} else {
TORCH_CHECK(out.dtype() == torch::kFloat16);
return cutlass_gemm_sm120_fp8_dispatch<cutlass::float_e4m3_t,
cutlass::half_t, Epilogue>(
out, a, b, std::forward<EpilogueArgs>(epilogue_args)...);
}
}
} // namespace vllm