[torch.compile] Add support for non-contiguous fused RMSNorm + group quant (#36551)

Signed-off-by: Luka Govedič <lgovedic@redhat.com>
Signed-off-by: Luka Govedič <ProExpertProg@users.noreply.github.com>
Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>
Co-authored-by: ProExpertProg <11367180+ProExpertProg@users.noreply.github.com>

.buildkite/test_areas/compile.yaml

@@ -101,8 +101,8 @@ steps:
     - nvidia-smi
     # Run all models and attn backends but only Inductor partition and native custom ops
     - pytest -v -s tests/compile/fusions_e2e/test_tp1_quant.py -k "inductor_partition and not +rms_norm and not +quant_fp8"
-    # Qwen requires +quant_fp8 as -quant_fp8 rms+quant fusion is not supported
-    - pytest -v -s tests/compile/fusions_e2e/test_tp1_quant.py -k "inductor_partition and not +rms_norm and +quant_fp8 and qwen3"
+    # Qwen/Deepseek requires +quant_fp8 as -quant_fp8 rms+quant fusion is not supported
+    - pytest -v -s tests/compile/fusions_e2e/test_tp1_quant.py -k "inductor_partition and not +rms_norm and +quant_fp8 and (qwen3 or deepseek)"
 
 - label: Fusion E2E Config Sweep (H100)
   timeout_in_minutes: 30
@@ -132,9 +132,9 @@ steps:
   commands:
     - nvidia-smi
     # Run all models but only FLASHINFER, Inductor partition and native custom ops
-    # Qwen requires +quant_fp8 as -quant_fp8 rms+quant fusion is not supported
+    # Qwen/Deepseek requires +quant_fp8 as -quant_fp8 rms+quant fusion is not supported
     # Run just llama3 (fp8 & fp4) for all config combinations (only inductor partition)
-    - pytest -v -s tests/compile/fusions_e2e/test_tp1_quant.py -k "inductor_partition and (FLASHINFER and not +rms_norm and (not +quant_fp8 or +quant_fp8 and qwen3) or llama-3)"
+    - pytest -v -s tests/compile/fusions_e2e/test_tp1_quant.py -k "inductor_partition and (FLASHINFER and not +rms_norm and (not +quant_fp8 or +quant_fp8 and (qwen3 or deepseek)) or llama-3)"
 
 - label: Fusion E2E TP2 Quick (H100)
   timeout_in_minutes: 20
@@ -150,8 +150,8 @@ steps:
   commands:
     - nvidia-smi
     # Run all models and attn backends but only Inductor partition and native custom ops
-    - pytest -v -s tests/compile/fusions_e2e/test_tp2_ar_rms.py -k "inductor_partition and not +rms_norm and not +quant_fp8"
-    - pytest -v -s tests/compile/fusions_e2e/test_tp2_async_tp.py -k "inductor_partition and not +rms_norm and not +quant_fp8"
+    - pytest -v -s tests/compile/fusions_e2e/test_tp2_ar_rms.py -k "inductor_partition and not +rms_norm and (not +quant_fp8 or +quant_fp8 and (qwen3 or deepseek))"
+    - pytest -v -s tests/compile/fusions_e2e/test_tp2_async_tp.py -k "inductor_partition and not +rms_norm and (not +quant_fp8 or +quant_fp8 and (qwen3 or deepseek))"
 
 - label: Fusion E2E TP2 AR-RMS Config Sweep (H100)
   timeout_in_minutes: 40
@@ -205,7 +205,7 @@ steps:
   commands:
     - nvidia-smi
     # Run all models but only FLASHINFER, Inductor partition and native custom ops
-    # include qwen with +quant_fp8 as -quant_fp8 rms+quant fusion is not supported
+    # include qwen/deepseek with +quant_fp8 as -quant_fp8 rms+quant fusion is not supported
     # for ar-rms-quant-fp4, also sweep llama3
-    - pytest -v -s tests/compile/fusions_e2e/test_tp2_ar_rms.py -k "(FLASHINFER and inductor_partition and not +rms_norm and (not +quant_fp8 or +quant_fp8 and qwen3)) or Llama-3.1-8B-Instruct-FP4"
-    - pytest -v -s tests/compile/fusions_e2e/test_tp2_async_tp.py -k "FLASHINFER and inductor_partition and not +rms_norm and (not +quant_fp8 or +quant_fp8 and qwen3)"
+    - pytest -v -s tests/compile/fusions_e2e/test_tp2_ar_rms.py -k "(FLASHINFER and inductor_partition and not +rms_norm and (not +quant_fp8 or +quant_fp8 and (qwen3 or deepseek))) or Llama-3.1-8B-Instruct-FP4"
+    - pytest -v -s tests/compile/fusions_e2e/test_tp2_async_tp.py -k "FLASHINFER and inductor_partition and not +rms_norm and (not +quant_fp8 or +quant_fp8 and (qwen3 or deepseek))"

csrc/quantization/fused_kernels/fused_layernorm_dynamic_per_token_quant.cu

@@ -15,31 +15,33 @@ __device__ void rms_norm_dynamic_per_token_quant_vec(
     scalar_t const* __restrict__ input,   // [..., hidden_size]
     scalar_t const* __restrict__ weight,  // [hidden_size]
     float const* scale_ub, float const var_epsilon, int32_t const hidden_size,
-    scalar_t* __restrict__ residual = nullptr) {
+    int32_t const input_stride, scalar_t* __restrict__ residual = nullptr) {
   float rms = 0.0f;
   float token_scale = 0.0f;
 
   // Compute rms
   vllm::vectorized::compute_rms<scalar_t, has_residual>(
-      &rms, input, hidden_size, var_epsilon, residual);
+      &rms, input, hidden_size, input_stride, var_epsilon, residual);
 
   // Compute scale
   vllm::vectorized::compute_dynamic_per_token_scales<scalar_t, scalar_out_t,
                                                      has_residual>(
       &token_scale, scales, input, weight, rms, scale_ub, hidden_size,
-      residual);
+      input_stride, residual);
 
   // RMS Norm + Quant
   if constexpr (std::is_same_v<scalar_out_t, int8_t>) {
     token_scale = 1.0f / token_scale;
     vllm::vectorized::norm_and_quant<scalar_t, scalar_out_t, true,
-                                     has_residual>(
-        out, input, weight, rms, &token_scale, hidden_size, residual);
+                                     has_residual>(out, input, weight, rms,
+                                                   &token_scale, hidden_size,
+                                                   input_stride, residual);
   } else {
     // FP8 - Do not invert token_scale for exact match with FBGemm
     vllm::vectorized::norm_and_quant<scalar_t, scalar_out_t, false,
-                                     has_residual>(
-        out, input, weight, rms, &token_scale, hidden_size, residual);
+                                     has_residual>(out, input, weight, rms,
+                                                   &token_scale, hidden_size,
+                                                   input_stride, residual);
   }
 }
 
@@ -51,38 +53,40 @@ __global__ void rms_norm_dynamic_per_token_quant_kernel(
     scalar_t const* __restrict__ input,   // [..., hidden_size]
     scalar_t const* __restrict__ weight,  // [hidden_size]
     float const* scale_ub, float const var_epsilon, int32_t const hidden_size,
-    scalar_t* __restrict__ residual = nullptr) {
+    int32_t const input_stride, scalar_t* __restrict__ residual = nullptr) {
   // For vectorization, token_input and token_output pointers need to be
   // aligned at 8-byte and 4-byte addresses respectively.
-  bool const can_vectorize = hidden_size % 4 == 0;
+  bool const can_vectorize = hidden_size % 4 == 0 and input_stride % 4 == 0;
 
   if (can_vectorize) {
     return rms_norm_dynamic_per_token_quant_vec<scalar_t, scalar_out_t,
                                                 has_residual>(
         out, scales, input, weight, scale_ub, var_epsilon, hidden_size,
-        residual);
+        input_stride, residual);
   }
 
   float rms = 0.0f;
   float token_scale = 0.0f;
 
   // Compute RMS
-  vllm::compute_rms<scalar_t, has_residual>(&rms, input, hidden_size,
-                                            var_epsilon, residual);
+  vllm::compute_rms<scalar_t, has_residual>(
+      &rms, input, hidden_size, input_stride, var_epsilon, residual);
   // Compute Scale
   vllm::compute_dynamic_per_token_scales<scalar_t, scalar_out_t, has_residual>(
       &token_scale, scales, input, weight, rms, scale_ub, hidden_size,
-      residual);
+      input_stride, residual);
 
   // RMS Norm + Quant
   if constexpr (std::is_same_v<scalar_out_t, int8_t>) {
     token_scale = 1.0f / token_scale;
     vllm::norm_and_quant<scalar_t, scalar_out_t, true, has_residual>(
-        out, input, weight, rms, &token_scale, hidden_size, residual);
+        out, input, weight, rms, &token_scale, hidden_size, input_stride,
+        residual);
   } else {
     // FP8 - Do not invert s_token_scale for exact match with FBGemm
     vllm::norm_and_quant<scalar_t, scalar_out_t, false, has_residual>(
-        out, input, weight, rms, &token_scale, hidden_size, residual);
+        out, input, weight, rms, &token_scale, hidden_size, input_stride,
+        residual);
   }
 }
 
@@ -97,19 +101,20 @@ __global__ void rms_norm_per_block_quant_kernel(
     scalar_t const* __restrict__ input,   // [..., hidden_size]
     scalar_t const* __restrict__ weight,  // [hidden_size]
     float const* scale_ub, float const var_epsilon, int32_t const hidden_size,
-    scalar_t* __restrict__ residual = nullptr, int64_t outer_scale_stride = 1) {
+    int32_t const input_stride, scalar_t* __restrict__ residual = nullptr,
+    int64_t outer_scale_stride = 1) {
   float rms;
   // Compute RMS
   // Always able to vectorize due to constraints on hidden_size
   vllm::vectorized::compute_rms<scalar_t, has_residual>(
-      &rms, input, hidden_size, var_epsilon, residual);
+      &rms, input, hidden_size, input_stride, var_epsilon, residual);
 
   // Compute Scale
   // Always able to vectorize due to constraints on hidden_size and group_size
   vllm::vectorized::compute_dynamic_per_token_scales<
       scalar_t, scalar_out_t, has_residual, is_scale_transposed, group_size>(
-      nullptr, scales, input, weight, rms, scale_ub, hidden_size, residual,
-      outer_scale_stride);
+      nullptr, scales, input, weight, rms, scale_ub, hidden_size, input_stride,
+      residual, outer_scale_stride);
 
   // RMS Norm + Quant
   // Always able to vectorize due to constraints on hidden_size
@@ -120,7 +125,7 @@ __global__ void rms_norm_per_block_quant_kernel(
   vllm::vectorized::norm_and_quant<
       scalar_t, scalar_out_t, std::is_same_v<scalar_out_t, int8_t>,
       has_residual, is_scale_transposed, group_size>(
-      out, input, weight, rms, scales, hidden_size, residual,
+      out, input, weight, rms, scales, hidden_size, input_stride, residual,
       outer_scale_stride);
 }
 
@@ -137,6 +142,7 @@ void rms_norm_dynamic_per_token_quant_dispatch(
     std::optional<at::Tensor> const& scale_ub,
     std::optional<at::Tensor>& residual) {
   int32_t hidden_size = input.size(-1);
+  int32_t input_stride = input.view({-1, hidden_size}).stride(0);
   auto num_tokens = input.numel() / hidden_size;
 
   dim3 grid(num_tokens);
@@ -153,7 +159,7 @@ void rms_norm_dynamic_per_token_quant_dispatch(
                   out.data_ptr<scalar_t>(), scales.data_ptr<float>(),
                   input.data_ptr<scalar_in_t>(), weight.data_ptr<scalar_in_t>(),
                   scale_ub.has_value() ? scale_ub->data_ptr<float>() : nullptr,
-                  var_epsilon, hidden_size,
+                  var_epsilon, hidden_size, input_stride,
                   has_residual ? residual->data_ptr<scalar_in_t>() : nullptr);
         });
   });
@@ -170,7 +176,9 @@ void rms_norm_dynamic_per_token_quant(
                                         ? c10::ScalarType::Float8_e4m3fn
                                         : c10::ScalarType::Float8_e4m3fnuz;
   TORCH_CHECK(out.dtype() == kFp8Type || out.dtype() == torch::kInt8);
-  TORCH_CHECK(out.is_contiguous() && input.is_contiguous());
+  TORCH_CHECK(out.is_contiguous());
+  TORCH_CHECK(input.stride(-1) == 1,
+              "Input must be contiguous in the last dimension");
 
   if (scale_ub.has_value()) {
     TORCH_CHECK(out.dtype() == kFp8Type);
@@ -179,6 +187,7 @@ void rms_norm_dynamic_per_token_quant(
   TORCH_CHECK(scales.dtype() == torch::kFloat32);
   if (residual) {
     TORCH_CHECK(residual->scalar_type() == input.scalar_type());
+    TORCH_CHECK(residual->is_contiguous());
   }
 
   VLLM_DISPATCH_FLOATING_TYPES(
@@ -200,6 +209,15 @@ void rms_norm_per_block_quant_dispatch(
     std::optional<at::Tensor> const& scale_ub,
     std::optional<at::Tensor>& residual, bool is_scale_transposed) {
   int32_t hidden_size = input.size(-1);
+  int32_t input_stride = input.view({-1, hidden_size}).stride(0);
+
+  TORCH_CHECK(hidden_size % 4 == 0,
+              "Hidden size must be divisible by 4 for vectorized access");
+  TORCH_CHECK(input_stride % 4 == 0,
+              "Input stride must be divisible by 4 for vectorized access");
+  TORCH_CHECK(group_size % 4 == 0,
+              "Group size must be divisible by 4 for vectorized access");
+
   auto num_tokens = input.numel() / hidden_size;
 
   dim3 grid(num_tokens);
@@ -225,7 +243,7 @@ void rms_norm_per_block_quant_dispatch(
                             weight.data_ptr<scalar_in_t>(),
                             scale_ub.has_value() ? scale_ub->data_ptr<float>()
                                                  : nullptr,
-                            var_epsilon, hidden_size,
+                            var_epsilon, hidden_size, input_stride,
                             has_residual ? residual->data_ptr<scalar_in_t>()
                                          : nullptr,
                             scales.stride(1));
@@ -246,7 +264,9 @@ void rms_norm_per_block_quant(torch::Tensor& out, torch::Tensor const& input,
                                         ? c10::ScalarType::Float8_e4m3fn
                                         : c10::ScalarType::Float8_e4m3fnuz;
   TORCH_CHECK(out.dtype() == kFp8Type || out.dtype() == torch::kInt8);
-  TORCH_CHECK(out.is_contiguous() && input.is_contiguous());
+  TORCH_CHECK(out.is_contiguous());
+  TORCH_CHECK(input.stride(-1) == 1,
+              "Input must be contiguous in the last dimension");
 
   if (scale_ub.has_value()) {
     TORCH_CHECK(out.dtype() == kFp8Type);
@@ -255,6 +275,7 @@ void rms_norm_per_block_quant(torch::Tensor& out, torch::Tensor const& input,
   TORCH_CHECK(scales.dtype() == torch::kFloat32);
   if (residual) {
     TORCH_CHECK(residual->scalar_type() == input.scalar_type());
+    TORCH_CHECK(residual->is_contiguous());
   }
 
   TORCH_CHECK(group_size == 128 || group_size == 64,

csrc/quantization/fused_kernels/layernorm_utils.cuh

@@ -16,14 +16,17 @@ namespace vllm {
 // has_residual must be true, if residual is not a nullptr
 template <typename scalar_t, bool has_residual = false>
 __device__ void compute_rms(float* rms, scalar_t const* __restrict__ input,
-                            int32_t const hidden_size, float const epsilon,
+                            int32_t const hidden_size,
+                            int32_t const input_stride, float const epsilon,
                             scalar_t const* __restrict__ residual = nullptr) {
+  int64_t const input_token_offset =
+      blockIdx.x * static_cast<int64_t>(input_stride);
   int64_t const token_offset = blockIdx.x * static_cast<int64_t>(hidden_size);
   // sum of squares
   float ss = 0.0f;
 
   for (auto i = threadIdx.x; i < hidden_size; i += blockDim.x) {
-    float x = static_cast<float>(input[token_offset + i]);
+    float x = static_cast<float>(input[input_token_offset + i]);
     if constexpr (has_residual) {
       x += static_cast<float>(residual[token_offset + i]);
     }
@@ -73,15 +76,20 @@ __device__ void compute_dynamic_per_token_scales(
     float* __restrict__ token_scale, float* __restrict__ all_token_scales,
     scalar_t const* __restrict__ input, scalar_t const* __restrict__ weight,
     float const rms, float const* __restrict__ scale_ub,
-    int32_t const hidden_size, scalar_t const* __restrict__ residual = nullptr,
+    int32_t const hidden_size, int32_t const input_stride,
+    scalar_t const* __restrict__ residual = nullptr,
     int32_t const group_size = 0, int64_t outer_scale_stride = 1) {
   float block_absmax_val_maybe = 0.0f;
   constexpr scalar_out_t qmax{quant_type_max_v<scalar_out_t>};
   __syncthreads();
-  if (group_size > 0) {
-    __shared__ float s_max_vals[1024];
+
+  int64_t const input_token_offset =
+      blockIdx.x * static_cast<int64_t>(input_stride);
   int64_t const token_offset = blockIdx.x * static_cast<int64_t>(hidden_size);
+
+  if (group_size > 0) {
     int64_t num_groups = hidden_size / group_size;
+    __shared__ float s_max_vals[1024];
     int64_t const threads_per_group = blockDim.x / num_groups;
     int64_t const thread_in_group = threadIdx.x % threads_per_group;
     int64_t const group_offset = threadIdx.x / threads_per_group * group_size;
@@ -89,7 +97,7 @@ __device__ void compute_dynamic_per_token_scales(
     int64_t const thread_end =
         min(group_offset + group_size, static_cast<int64_t>(hidden_size));
     for (auto i = thread_offset; i < thread_end; i += threads_per_group) {
-      float x = static_cast<float>(input[token_offset + i]);
+      float x = static_cast<float>(input[input_token_offset + i]);
       if constexpr (has_residual) {
         x += static_cast<float>(residual[token_offset + i]);
       }
@@ -144,10 +152,8 @@ __device__ void compute_dynamic_per_token_scales(
     }
     __syncthreads();
   } else {
-    int64_t const token_offset = blockIdx.x * static_cast<int64_t>(hidden_size);
-
     for (auto i = threadIdx.x; i < hidden_size; i += blockDim.x) {
-      float x = static_cast<float>(input[token_offset + i]);
+      float x = static_cast<float>(input[input_token_offset + i]);
       if constexpr (has_residual) {
         x += static_cast<float>(residual[token_offset + i]);
       }
@@ -185,12 +191,15 @@ template <typename scalar_t, typename scalar_out_t, bool is_scale_inverted,
 __device__ void norm_and_quant(
     scalar_out_t* __restrict__ output, scalar_t const* __restrict__ input,
     scalar_t const* __restrict__ weight, float const rms, float* const scale,
-    int32_t const hidden_size, scalar_t* __restrict__ residual = nullptr,
-    int32_t const group_size = 0, int64_t outer_scale_stride = 1) {
+    int32_t const hidden_size, int32_t const input_stride,
+    scalar_t* __restrict__ residual = nullptr, int32_t const group_size = 0,
+    int64_t outer_scale_stride = 1) {
+  int64_t const input_token_offset =
+      blockIdx.x * static_cast<int64_t>(input_stride);
   int64_t const token_offset = blockIdx.x * static_cast<int64_t>(hidden_size);
 
   for (auto i = threadIdx.x; i < hidden_size; i += blockDim.x) {
-    float x = static_cast<float>(input[token_offset + i]);
+    float x = static_cast<float>(input[input_token_offset + i]);
     if constexpr (has_residual) {
       x += static_cast<float>(residual[token_offset + i]);
       residual[token_offset + i] = static_cast<scalar_t>(x);
@@ -224,13 +233,16 @@ namespace vectorized {
 // hidden_size must be a multiple of 4
 template <typename scalar_t, bool has_residual = false>
 __device__ void compute_rms(float* rms, scalar_t const* __restrict__ input,
-                            int32_t const hidden_size, float const epsilon,
+                            int32_t const hidden_size,
+                            int32_t const input_stride, float const epsilon,
                             scalar_t const* __restrict__ residual = nullptr) {
+  int64_t const input_token_offset =
+      blockIdx.x * static_cast<int64_t>(input_stride);
   int64_t const token_offset = blockIdx.x * static_cast<int64_t>(hidden_size);
 
   // Vectorized input/output to better utilize memory bandwidth.
   vec4_t<scalar_t> const* vec_input =
-      reinterpret_cast<vec4_t<scalar_t> const*>(&input[token_offset]);
+      reinterpret_cast<vec4_t<scalar_t> const*>(&input[input_token_offset]);
   vec4_t<scalar_t> const* vec_residual = nullptr;
   if constexpr (has_residual) {
     vec_residual =
@@ -288,7 +300,8 @@ __device__ void compute_dynamic_per_token_scales(
     float* __restrict__ token_scale, float* __restrict__ all_token_scales,
     scalar_t const* __restrict__ input, scalar_t const* __restrict__ weight,
     float const rms, float const* __restrict__ scale_ub,
-    int32_t const hidden_size, scalar_t const* __restrict__ residual = nullptr,
+    int32_t const hidden_size, int32_t const input_stride,
+    scalar_t const* __restrict__ residual = nullptr,
     int64_t outer_scale_stride = 1) {
   constexpr scalar_out_t qmax{quant_type_max_v<scalar_out_t>};
 
@@ -300,10 +313,13 @@ __device__ void compute_dynamic_per_token_scales(
   vec4_t<scalar_t> const* vec_weight = nullptr;
   vec4_t<scalar_t> const* vec_residual = nullptr;
 
+  int64_t const input_token_offset =
+      blockIdx.x * static_cast<int64_t>(input_stride);
+  int64_t const token_offset = blockIdx.x * static_cast<int64_t>(hidden_size);
+
   if constexpr (group_size > 0) {
     __shared__ float s_max_vals[1024];
 
-    int64_t const token_offset = blockIdx.x * static_cast<int64_t>(hidden_size);
     int64_t const num_groups = hidden_size / group_size;
     int64_t const threads_per_group = blockDim.x / num_groups;
     int64_t const thread_in_group = threadIdx.x % threads_per_group;
@@ -312,7 +328,8 @@ __device__ void compute_dynamic_per_token_scales(
     int64_t const thread_offset = group_offset + thread_in_group;
     int64_t const thread_end = min(group_offset + (group_size >> 2),
                                    static_cast<int64_t>(hidden_size >> 2));
-    vec_input = reinterpret_cast<vec4_t<scalar_t> const*>(&input[token_offset]);
+    vec_input =
+        reinterpret_cast<vec4_t<scalar_t> const*>(&input[input_token_offset]);
     vec_weight = reinterpret_cast<vec4_t<scalar_t> const*>(weight);
     if constexpr (has_residual) {
       vec_residual =
@@ -396,8 +413,8 @@ __device__ void compute_dynamic_per_token_scales(
     __syncthreads();
 
   } else {
-    int64_t const token_offset = blockIdx.x * static_cast<int64_t>(hidden_size);
-    vec_input = reinterpret_cast<vec4_t<scalar_t> const*>(&input[token_offset]);
+    vec_input =
+        reinterpret_cast<vec4_t<scalar_t> const*>(&input[input_token_offset]);
     vec_weight = reinterpret_cast<vec4_t<scalar_t> const*>(weight);
     if constexpr (has_residual) {
       vec_residual =
@@ -462,18 +479,18 @@ __device__ void compute_dynamic_per_token_scales(
 template <typename scalar_t, typename scalar_out_t, bool is_scale_inverted,
           bool has_residual = false, bool is_scale_transposed = false,
           int32_t group_size = 0>
-__device__ void norm_and_quant(scalar_out_t* __restrict__ output,
-                               scalar_t const* __restrict__ input,
-                               scalar_t const* __restrict__ weight,
-                               float const rms, float* const scale,
-                               int32_t const hidden_size,
-                               scalar_t* __restrict__ residual = nullptr,
-                               int64_t outer_scale_stride = 1) {
+__device__ void norm_and_quant(
+    scalar_out_t* __restrict__ output, scalar_t const* __restrict__ input,
+    scalar_t const* __restrict__ weight, float const rms, float* const scale,
+    int32_t const hidden_size, int32_t const input_stride,
+    scalar_t* __restrict__ residual = nullptr, int64_t outer_scale_stride = 1) {
+  int64_t const input_token_offset =
+      blockIdx.x * static_cast<int64_t>(input_stride);
   int64_t const token_offset = blockIdx.x * static_cast<int64_t>(hidden_size);
 
   // Vectorized input/output/weight/residual to better utilize memory bandwidth.
   vec4_t<scalar_t> const* vec_input =
-      reinterpret_cast<vec4_t<scalar_t> const*>(&input[token_offset]);
+      reinterpret_cast<vec4_t<scalar_t> const*>(&input[input_token_offset]);
   vec4_t<scalar_t> const* vec_weight =
       reinterpret_cast<vec4_t<scalar_t> const*>(weight);
   q8x4_t<scalar_out_t>* vec_output =

tests/compile/fusions_e2e/conftest.py

@@ -72,6 +72,16 @@ def run_e2e_fusion_test(monkeypatch, caplog_mp_spawn):
 
         rocm_aiter_ops.refresh_env_variables()
 
+        # Filter here to reduce code duplication
+        requires_mla = "deepseek" in model_name.lower()
+        is_mla = "mla" in attn_backend.backend.name.lower()
+
+        if requires_mla != is_mla:
+            pytest.skip(
+                f"Incompatible model '{model_name}' and "
+                f"attention backend '{attn_backend.backend.name}'"
+            )
+
         # Disable, compile cache to make sure custom passes run.
         # Otherwise, we can't verify fusion happened through the logs.
         monkeypatch.setenv("VLLM_DISABLE_COMPILE_CACHE", "1")

tests/compile/fusions_e2e/models.py

@@ -44,6 +44,20 @@ ROCM_AITER_UNIFIED_ATTN = pytest.param(
     ),
 )
 
+FLASHINFER_MLA_ATTN = pytest.param(
+    AttentionBackendCase(backend=AttentionBackendEnum.FLASHINFER_MLA),
+    id="FLASHINFER_MLA",
+    marks=pytest.mark.skipif(
+        not is_blackwell() or not has_flashinfer(),
+        reason="FI backend requires Blackwell and FlashInfer",
+    ),
+)
+
+TRITON_MLA_ATTN = pytest.param(
+    AttentionBackendCase(backend=AttentionBackendEnum.TRITON_MLA),
+    id="TRITON_MLA",
+)
+
 # Models
 llama3_8b = ModelFusionInfo(
     model_name="meta-llama/Llama-3.1-8B-Instruct",
@@ -126,3 +140,25 @@ qwen3_a3b_fp8 = ModelFusionInfo(
         async_tp=n_layers * 2,
     ),
 )
+
+deepseek_v3_fp8 = ModelFusionInfo(
+    model_name="deepseek-ai/DeepSeek-V3",
+    matches=lambda n_layers: Matches(
+        # 3 per dense layer (first 3):
+        # - input_rms + qkv_proj
+        # - q_a_layernorm + q_b_proj (inside MLA wrapper)
+        # - post_attn_layernorm + MLP
+        # 2 per MoE layer (remaining) due to MoE wrapping
+        rms_quant_fusion=n_layers * 2 + min(3, n_layers),  # add for 3 dense layers
+        # TODO silu+block quant
+        #  act_quant_fusion=min(3, n_layers), # dense layers only
+        act_quant_fusion=0,
+        # MLA attn + quant not supported yet:
+        # https://github.com/vllm-project/vllm/issues/35792
+        attn_quant_fusion=0,
+        ar_rms_fusion=n_layers * 2 + 1,
+        # TODO
+        # sequence_parallel= n_layers * 2 + 1,
+        # async_tp=n_layers * 2,
+    ),
+)

tests/compile/fusions_e2e/test_tp1_quant.py

@@ -17,9 +17,12 @@ from .common import (
 )
 from .models import (
     FLASHINFER_ATTN,
+    FLASHINFER_MLA_ATTN,
     ROCM_AITER_UNIFIED_ATTN,
     ROCM_ATTN,
     TRITON_ATTN,
+    TRITON_MLA_ATTN,
+    deepseek_v3_fp8,
     llama3_8b_fp4,
     llama3_8b_fp8,
     llama4_scout_fp4,
@@ -33,6 +36,9 @@ from .models import (
     [
         (*llama3_8b_fp8, False),
         (*qwen3_a3b_fp8, False),
+        (*qwen3_a3b_fp8, True),
+        (*deepseek_v3_fp8, False),
+        (*deepseek_v3_fp8, True),
         pytest.param(
             *llama4_scout_fp8,
             False,
@@ -41,13 +47,6 @@ from .models import (
                 reason="Llama4 Scout FP8 only supported on CUDA",
             ),
         ),
-        pytest.param(
-            *qwen3_a3b_fp8,
-            True,
-            marks=pytest.mark.skipif(
-                not current_platform.is_cuda(), reason="DeepGemm only supported on CUDA"
-            ),
-        ),
     ],
 )
 @pytest.mark.parametrize(
@@ -57,6 +56,8 @@ from .models import (
         FLASHINFER_ATTN,
         ROCM_ATTN,
         ROCM_AITER_UNIFIED_ATTN,
+        FLASHINFER_MLA_ATTN,
+        TRITON_MLA_ATTN,
     ],
 )
 @pytest.mark.parametrize("n_layers", [6])
@@ -75,6 +76,9 @@ def test_tp1_fp8_fusions(
     run_e2e_fusion_test,
     monkeypatch,
 ):
+    if use_deepgemm and not current_platform.is_cuda():
+        pytest.skip("DeepGemm only supported on CUDA")
+
     if use_deepgemm and is_flashinfer_fp8_blockscale_gemm_supported():
         # Flashinfer block FP8 GEMM has internal quantization, so it can't
         # be fused with other ops.
@@ -86,7 +90,8 @@ def test_tp1_fp8_fusions(
 
     matches = matches_fn(n_layers)
 
-    if "qwen" in model_name.lower() and "-quant_fp8" in custom_ops:
+    block_fp8 = "qwen" in model_name.lower() or "deepseek" in model_name.lower()
+    if block_fp8 and "-quant_fp8" in custom_ops:
         # This is why config forces +quant_fp8 by default
         pytest.skip("native QuantFP8 matching not supported for group quant")
 

tests/compile/fusions_e2e/test_tp2_ar_rms.py

@@ -17,7 +17,9 @@ from .common import (
 )
 from .models import (
     FLASHINFER_ATTN,
+    FLASHINFER_MLA_ATTN,
     TRITON_ATTN,
+    deepseek_v3_fp8,
     llama3_8b,
     llama3_8b_fp4,
     llama3_8b_fp8,
@@ -33,10 +35,12 @@ pytestmark = pytest.mark.skipif(not current_platform.is_cuda(), reason="Only tes
 @multi_gpu_test(num_gpus=2)
 @pytest.mark.parametrize(
     "model_name, matches_fn, model_kwargs, hf_overrides",
-    # qwen3-fp8 should still fuse AR+rms even though group quant is not yet supported
-    [llama3_8b_fp8, llama4_scout_fp8, qwen3_a3b_fp8],
+    # qwen3 & dsv3 should still fuse AR+rms even though group quant is not yet supported
+    [llama3_8b_fp8, llama4_scout_fp8, qwen3_a3b_fp8, deepseek_v3_fp8],
+)
+@pytest.mark.parametrize(
+    "attn_backend", [TRITON_ATTN, FLASHINFER_ATTN, FLASHINFER_MLA_ATTN]
 )
-@pytest.mark.parametrize("attn_backend", [TRITON_ATTN, FLASHINFER_ATTN])
 @pytest.mark.parametrize("n_layers", [4])
 @pytest.mark.parametrize("custom_ops", custom_ops_combos("quant_fp8", "rms_norm"))
 @pytest.mark.parametrize("inductor_graph_partition", INDUCTOR_GRAPH_PARTITION)
@@ -54,7 +58,8 @@ def test_tp2_ar_rms_fp8_fusions(
 ):
     matches = matches_fn(n_layers)
 
-    if "qwen" in model_name.lower() and "-quant_fp8" in custom_ops:
+    block_fp8 = "qwen" in model_name.lower() or "deepseek" in model_name.lower()
+    if block_fp8 and "-quant_fp8" in custom_ops:
         # This is why config forces +quant_fp8 by default
         pytest.skip("native QuantFP8 matching not supported for group quant")
 

tests/kernels/core/test_fused_quant_layernorm.py

@@ -162,6 +162,7 @@ def ops_impl(
 )
 @pytest.mark.parametrize("seed", SEEDS)
 @pytest.mark.parametrize("device", CUDA_DEVICES)
+@pytest.mark.parametrize("strided_input", [False, True])
 @torch.inference_mode()
 def test_rms_norm(
     default_vllm_config,
@@ -175,6 +176,7 @@ def test_rms_norm(
     tma_alignment: int,
     seed: int,
     device: str,
+    strided_input: bool,
 ) -> None:
     torch.random.manual_seed(seed)
     if torch.cuda.is_available():
@@ -184,17 +186,17 @@ def test_rms_norm(
 
     if group_size is not None and hidden_size % group_size[1] != 0:
         # skip
-        return
+        pytest.skip("Skip non-divisible group sizes")
 
     if group_size is not None and has_scale_ub:
         # blockwise baseline doesn't support scale_ub
-        return
+        pytest.skip("scale_ub not supported for blockwise/group quantization")
 
     if (
         group_size is None or quant_dtype != current_platform.fp8_dtype()
     ) and tma_alignment != 0:
         # TMA alignment is only supported for groupwise fp8 kernels
-        return
+        pytest.skip("tma alignment not supported for per-token or int8 quantization")
 
     if (
         group_size is not None
@@ -202,21 +204,36 @@ def test_rms_norm(
         and hidden_size // group_size[1] % tma_alignment == 0
     ):
         # Skip tests where TMA alignment doesn't create extra padding to save time
-        return
+        pytest.skip("Skip TMA alignment cases where no extra padding is added")
 
     if has_scale_ub and quant_dtype != current_platform.fp8_dtype():
         # skip
-        return
+        pytest.skip("scale_ub only supported for fp8 quantization")
 
     layer = RMSNorm(hidden_size, EPS).to(dtype=dtype)
 
     # Make weights
     layer.weight.data.normal_(mean=1.0, std=0.1)
 
-    # Make inputs
+    # Make inputs: use a wider tensor and slice to create a non-contiguous
+    # (strided) input when strided_input=True. The last dimension stride
+    # remains 1, which the kernel requires.
     scale = 1 / (hidden_size)
-    x = torch.randn(num_tokens, hidden_size, dtype=dtype) * scale
-    residual = torch.randn_like(x) * scale if add_residual else None
+    last_dim = 2 * hidden_size if strided_input else hidden_size
+    x = torch.randn(num_tokens, last_dim, dtype=dtype) * scale
+    x = x[:, :hidden_size]
+
+    # dim 1 gets special-cased
+    x_is_strided = strided_input and num_tokens != 1
+    # check that the input is strided iff we expect it to be
+    assert x.is_contiguous() != x_is_strided
+
+    # Residual must still be contiguous
+    residual = (
+        torch.randn(num_tokens, hidden_size, dtype=dtype) * scale
+        if add_residual
+        else None
+    )
     if has_scale_ub:
         rms_x, _ = ref_rms_norm(layer, x, residual)
         scale_ub = torch.mean(rms_x).to(dtype=torch.float32, device="cuda")
@@ -260,12 +277,33 @@ def test_rms_norm(
     if add_residual:
         assert torch.allclose(ref_residual, ops_residual)
 
-    output = torch.empty_like(x, dtype=quant_dtype)
+    output = torch.empty(x.shape, dtype=quant_dtype, device=x.device)
     scales = torch.empty(
         (x.numel() // x.shape[-1], 1), device=x.device, dtype=torch.float32
     )
 
+    if group_size is None:
         opcheck(
             torch.ops._C.rms_norm_dynamic_per_token_quant,
             (output, x, layer.weight, scales, 1e-5, scale_ub, residual),
         )
+    else:
+        # TODO(luka/eliza) opcheck is broken?
+        #  Somehow the cloned args are getting mutated in-place,
+        #  which causes the opcheck to fail.
+        # https://github.com/vllm-project/vllm/issues/36688
+        return
+        opcheck(
+            torch.ops._C.rms_norm_per_block_quant,
+            (
+                output,
+                x,
+                layer.weight,
+                scales,
+                1e-5,
+                scale_ub,
+                residual,
+                group_size[1],
+                True,  # is_scale_transposed
+            ),
+        )

vllm/_custom_ops.py

@@ -427,7 +427,7 @@ def rms_norm_dynamic_per_token_quant(
     scale_ub: torch.Tensor | None = None,
     residual: torch.Tensor | None = None,
 ) -> tuple[torch.Tensor, torch.Tensor]:
-    output = torch.empty_like(input, dtype=quant_dtype)
+    output = torch.empty(input.shape, dtype=quant_dtype, device=input.device)
     scales = torch.empty(
         (input.numel() // input.shape[-1], 1), device=input.device, dtype=torch.float32
     )
@@ -451,7 +451,7 @@ def rms_norm_per_block_quant(
     tma_alignment: int = 0,
 ) -> tuple[torch.Tensor, torch.Tensor]:
     assert len(group_size) == 2
-    output = torch.empty_like(input, dtype=quant_dtype)
+    output = torch.empty(input.shape, dtype=quant_dtype, device=input.device)
     if is_scale_transposed:
         if tma_alignment == 0:
             scales = torch.empty(