Import latest aicc hipcc fp8 pa snapshot.

Source: feature/aicc-hipcc-unified-attn-fp8-pa @ fc89765

csrc/flash_attn_hg/src/target/flash_varlen_fwd_permute_bhsd2bshd_hdim128.cpp

 #ifdef BUILD_FA_PERMUTE
 #include <hip/hip_runtime.h>
-#include "../../include/intrinsic.h"
 #include "../flash_fwd_permute_hdim128.h"
 
 template<>
@@ -141,27 +140,21 @@ __global__ void flash_fwd_varlen_permute_bhsd2bshd<128, 4, 32>(
         int32_t thread_offset = lane_id_col * 8;
         // 一次读取 4x128 的 Half 到 LDS
         #if defined(__gfx936__) || defined(__gfx938__)
-            {
-                auto *lds_ptr = (__attribute__((address_space(3))) int *)(
-                    reinterpret_cast<size_t>(lds) + static_cast<size_t>(lane_id * 4) * sizeof(float));
-                __builtin_hcu_raw_buffer_load_lds(
-                    read_buffer,
-                    lds_ptr,
-                    16,
-                    (block_offset + thread_offset) << 1, /* v_offset */
-                    0, /* s_offset */
-                    0, /* immediate offset, instruction offset */
-                    0  /* auxilariy data| bit 0: glc, bit 1: slc, bit 2: dlc, bit 3: cache swizzle */
-                );
-            }
+            __builtin_hcu_raw_buffer_load_lds(
+                read_buffer,
+                lds + lane_id * 4,
+                16,
+                (block_offset + thread_offset) << 1, /* v_offset */
+                0, /* s_offset */
+                0, /* immediate offset, instruction offset */
+                0  /* auxilariy data| bit 0: glc, bit 1: slc, bit 2: dlc, bit 3: cache swizzle */
+            );
         #else
             *(vec4_fp32*)(lds + lane_id * 4) = *(vec4_fp32*)(read_ptr + ((block_offset + thread_offset) >> 1));
         #endif
         // 从 LDS 转置后, 64 个线程写 4 行, 每次写 128 个 Half, 对应 fetch * 4 + [0,3] 的 seqlen
-        vec2_fp32 data0, data1;
-        inlineasm_fa_ds_read2_b32(lds, lane_id, data0, 0, 64);
-        inlineasm_fa_ds_read2_b32(lds, lane_id + 128, data1, 0, 64);
-        asm volatile("s_waitcnt lgkmcnt(0)\n");
+        vec2_fp32 data0 = __builtin_hcu_ds_read2_f32((__attribute__((address_space(3))) float*)lds + lane_id, 0, 64, false);
+        vec2_fp32 data1 = __builtin_hcu_ds_read2_f32((__attribute__((address_space(3))) float*)lds + lane_id + 128, 0, 64, false);
         write_ptr[(min(actual_seqlen - 1, fetch * 4 + 0) * num_heads * kHeadDim + (lane_id << 1)) >> 1] = data0[0];
         write_ptr[(min(actual_seqlen - 1, fetch * 4 + 1) * num_heads * kHeadDim + (lane_id << 1)) >> 1] = data0[1];
         write_ptr[(min(actual_seqlen - 1, fetch * 4 + 2) * num_heads * kHeadDim + (lane_id << 1)) >> 1] = data1[0];
@@ -370,4 +363,4 @@ __global__ void flash_fwd_varlen_permute_bhsd2bshd<256, 1, 32>(
 
 
 
-#endif
+#endif
\ No newline at end of file

csrc/flash_attn_hg/src/target/flash_varlen_fwd_permute_bshd2bhsd_hdim128.cpp

 #ifdef BUILD_FA_PERMUTE
 #include <hip/hip_runtime.h>
-#include "../../include/intrinsic.h"
 #include "../flash_fwd_permute_hdim128.h"
 
 
@@ -119,28 +118,22 @@ __global__ void flash_fwd_varlen_permute_bshd2bhsd<128, 4, 0>(
         int32_t thread_offset = lane_id_row * 128 + lane_id_col * 8;
         // block 地址 + thread 地址, << 1 是获取偏移的字节数, 写到 lds 是为了转置一下
         #if defined(__gfx936__) || defined(__gfx938__)
-            {
-                auto *lds_ptr = (__attribute__((address_space(3))) int *)(
-                    reinterpret_cast<size_t>(lds) + static_cast<size_t>(lane_id * 4) * sizeof(float));
-                __builtin_hcu_raw_buffer_load_lds(
-                    read_buffer,
-                    lds_ptr,
-                    16,
-                    (block_offset + thread_offset) << 1, /* v_offset */
-                    0, /* s_offset */
-                    0, /* immediate offset, instruction offset */
-                    0  /* auxilariy data| bit 0: glc, bit 1: slc, bit 2: dlc, bit 3: cache swizzle */
-                );
-            }
+            __builtin_hcu_raw_buffer_load_lds(
+                read_buffer,
+                lds + lane_id * 4,
+                16,
+                (block_offset + thread_offset) << 1, /* v_offset */
+                0, /* s_offset */
+                0, /* immediate offset, instruction offset */
+                0  /* auxilariy data| bit 0: glc, bit 1: slc, bit 2: dlc, bit 3: cache swizzle */
+            );
         #else
             *(vec4_fp32*)(lds + lane_id * 4) = *(vec4_fp32*)(read_ptr + ((block_offset + thread_offset) >> 1));
         #endif
         // 写到 lds 不需要同步, 因为只有一个 wave
         // 循环 seqlen_q 次, 每次间隔 4 x 128 个 half, 需要写 4 次
-        vec2_fp32 data0, data1;
-        inlineasm_fa_ds_read2_b32(lds, lane_id, data0, 0, 64);
-        inlineasm_fa_ds_read2_b32(lds, lane_id + 128, data1, 0, 64);
-        asm volatile("s_waitcnt lgkmcnt(0)\n");
+        vec2_fp32 data0 = __builtin_hcu_ds_read2_f32((__attribute__((address_space(3))) float*)lds + lane_id, 0, 64, false);
+        vec2_fp32 data1 = __builtin_hcu_ds_read2_f32((__attribute__((address_space(3))) float*)lds + lane_id + 128, 0, 64, false);
         write_ptr[(fetch * head_dim + (lane_id << 1) + 0 * cur_seqlen_q * head_dim) >> 1] = data0[0];
         write_ptr[(fetch * head_dim + (lane_id << 1) + 1 * cur_seqlen_q * head_dim) >> 1] = data0[1];
         write_ptr[(fetch * head_dim + (lane_id << 1) + 2 * cur_seqlen_q * head_dim) >> 1] = data1[0];
@@ -268,28 +261,22 @@ __global__ void flash_fwd_varlen_permute_bshd2bhsd<128, 4, 32>(
         int32_t thread_offset = lane_id_row * 128 + lane_id_col * 8;
         // block 地址 + thread 地址, << 1 是获取偏移的字节数, 写到 lds 是为了转置一下
         #if defined(__gfx936__) || defined(__gfx938__)
-            {
-                auto *lds_ptr = (__attribute__((address_space(3))) int *)(
-                    reinterpret_cast<size_t>(lds) + static_cast<size_t>(lane_id * 4) * sizeof(float));
-                __builtin_hcu_raw_buffer_load_lds(
-                    read_buffer,
-                    lds_ptr,
-                    16,
-                    (block_offset + thread_offset) << 1, /* v_offset */
-                    0, /* s_offset */
-                    0, /* immediate offset, instruction offset */
-                    0  /* auxilariy data| bit 0: glc, bit 1: slc, bit 2: dlc, bit 3: cache swizzle */
-                );
-            }
+            __builtin_hcu_raw_buffer_load_lds(
+                read_buffer,
+                lds + lane_id * 4,
+                16,
+                (block_offset + thread_offset) << 1, /* v_offset */
+                0, /* s_offset */
+                0, /* immediate offset, instruction offset */
+                0  /* auxilariy data| bit 0: glc, bit 1: slc, bit 2: dlc, bit 3: cache swizzle */
+            );
         #else
             *(vec4_fp32*)(lds + lane_id * 4) = *(vec4_fp32*)(read_ptr + ((block_offset + thread_offset) >> 1));
         #endif
         // 写到 lds 不需要同步, 因为只有一个 wave
         // 循环 seqlen_q 次, 每次间隔 4 x 128 个 half, 需要写 4 次
-        vec2_fp32 data0, data1;
-        inlineasm_fa_ds_read2_b32(lds, lane_id, data0, 0, 64);
-        inlineasm_fa_ds_read2_b32(lds, lane_id + 128, data1, 0, 64);
-        asm volatile("s_waitcnt lgkmcnt(0)\n");
+        vec2_fp32 data0 = __builtin_hcu_ds_read2_f32((__attribute__((address_space(3))) float*)lds + lane_id, 0, 64, false);
+        vec2_fp32 data1 = __builtin_hcu_ds_read2_f32((__attribute__((address_space(3))) float*)lds + lane_id + 128, 0, 64, false);
         write_ptr[(seqlen_limit * head_dim + (lane_id << 1) + 0 * cur_seqlen_q * head_dim) >> 1] = data0[0];
         write_ptr[(seqlen_limit * head_dim + (lane_id << 1) + 1 * cur_seqlen_q * head_dim) >> 1] = data0[1];
         write_ptr[(seqlen_limit * head_dim + (lane_id << 1) + 2 * cur_seqlen_q * head_dim) >> 1] = data1[0];
@@ -383,9 +370,8 @@ __global__ void __launch_bounds__(64, 1) flash_fwd_varlen_permute_bshd2bhsd<128,
             __builtin_amdgcn_sched_barrier(0);
         #endif
         // 循环 seqlen_q 次, 每次间隔 4 x 128 个 half, 需要写 4 次
-        inlineasm_fa_ds_read2_b32(lds, fetch * 256 + lane_id, registers_buffer[fetch * 2], 0, 64);
-        inlineasm_fa_ds_read2_b32(lds, fetch * 256 + lane_id + 128, registers_buffer[fetch * 2 + 1], 0, 64);
-        asm volatile("s_waitcnt lgkmcnt(0)\n");
+        registers_buffer[fetch * 2]     = __builtin_hcu_ds_read2_f32((__attribute__((address_space(3))) float*)lds + fetch * 256 + lane_id, 0, 64, false);
+        registers_buffer[fetch * 2 + 1] = __builtin_hcu_ds_read2_f32((__attribute__((address_space(3))) float*)lds + fetch * 256 + lane_id + 128, 0, 64, false);
     }
     __builtin_amdgcn_sched_barrier(0);
 
@@ -688,4 +674,4 @@ template<>
 __global__ void __launch_bounds__(64, 1) flash_fwd_varlen_permute_bshd2bhsd<256, 4, 32>(
         void* output, void* query, void* split_sizes, int64_t head_stride, int32_t num_heads, int real_headdim) {}
 
-#endif // end of BUILD_FA_PERMUTE
+#endif // end of BUILD_FA_PERMUTE
\ No newline at end of file

flash_attn/__init__.py

@@ -26,7 +26,6 @@ if torch.cuda.is_available():
         flash_attn_varlen_with_mask_func,
         # unified attn functions 
         varlen_fwd_unified,
-        fwd_sparse_mean_pool_fast,
     )
     # triton fa interface
     from flash_attn.flash_attn_triton_interface import flash_attn_func as triton_flash_attn_func

flash_attn/flash_attn_interface.py

@@ -2,7 +2,6 @@
 
 from typing import Optional, Union
 from typing import List, Tuple
-import os
 import torch
 import torch.nn as nn
 import torch.nn.functional as F
@@ -19,6 +18,12 @@ from flash_attn.utils.sparse_utils import hyperparameter_check, get_block_map_me
 
 DEFAULT_FA_VERSION = 2
 
+try:
+    torch._C._dispatch_find_schema_or_throw("flash_attn2_c_op::varlen_fwd", "")
+    _has_flash_attn2_c_varlen_fwd = True
+except RuntimeError:
+    _has_flash_attn2_c_varlen_fwd = False
+
 def maybe_contiguous(x):
     return x.contiguous() if x is not None and x.stride(-1) != 1 else x
 
@@ -59,7 +64,7 @@ def _get_block_size_n(device, head_dim, is_dropout, is_causal):
     elif head_dim <= 512:
         return 64
 
-if torch.__version__ >= "2.4.0":
+if torch.__version__ >= "2.4.0" and _has_flash_attn2_c_varlen_fwd:
     _torch_custom_op_wrapper = torch.library.custom_op
     _torch_register_fake_wrapper = torch.library.register_fake
 else:
@@ -199,7 +204,11 @@ def varlen_fwd_fake(
     return out, softmax_lse, p, rng_state
 
 
-_wrapped_flash_attn_varlen_forward = torch.ops.flash_attn2_c_op.varlen_fwd
+_wrapped_flash_attn_varlen_forward = (
+    torch.ops.flash_attn2_c_op.varlen_fwd
+    if _has_flash_attn2_c_varlen_fwd
+    else _flash_attn_varlen_forward
+)
 
 
 def _flash_attn_backward(
@@ -2008,7 +2017,7 @@ def vllm_flash_attn_varlen_func(
         # if mtp, k head must be 1. 
         # todo : support k head >1
         is_mtp = (max_seqlen_q*bs==total_q and max_seqlen_q>1 and max_seqlen_q<5)
-        if  (max_seqlen_q==1 or is_mtp ) and real_window_size[0]==-1:
+        if  (max_seqlen_q==1 or (is_mtp and k.shape[1]==1)) and real_window_size[0]==-1:
             if out==None:
                 if q.dtype == torch.float8_e4m3fn or q.dtype == torch.float8_e5m2:
                     out = torch.empty(q.size(),device = q.device,dtype=torch.bfloat16)
@@ -2732,6 +2741,9 @@ def varlen_fwd_unified(
     *,
     out=None,
     return_softmax_lse=False,
+    q_descale=None,
+    k_descale=None,
+    v_descale=None,
 ):
     if softmax_scale is None:
         softmax_scale = q.shape[-1] ** (-0.5)
@@ -2741,6 +2753,78 @@ def varlen_fwd_unified(
 
     window_size_left, window_size_right = window_size
 
+    if k.dtype.is_floating_point:
+        k_dtype_bits = torch.finfo(k.dtype).bits
+    else:
+        k_dtype_bits = torch.iinfo(k.dtype).bits
+
+    is_mtp = (max_seqlen_q * seqused_k.size(0) == q.shape[0] and 1 < max_seqlen_q < 16)
+
+    if max_seqlen_q >= 16:
+        bshd_prefill = _require_hg_varlen_symbol("hg_prefix_prefill_varlen_fwd")
+        fa_output, *rest_extend = bshd_prefill(
+            q,
+            k,
+            v,
+            out, # out_
+            cu_seqlens_q,
+            None, # cu_seqlens_k
+            seqused_k,
+            alibi_slopes,
+            block_table,
+            max_seqlen_q,
+            max_seqlen_k,
+            0.0, # dropout
+            softmax_scale,
+            False, # zero_tensors
+            causal,
+            window_size[0],
+            window_size[1],
+            softcap,
+            return_softmax_lse,
+            1,
+            None if (k_dtype_bits == 16) else q_descale,
+            None if (k_dtype_bits == 16) else k_descale,
+            None if (k_dtype_bits == 16) else v_descale,
+            True,
+        )
+        return (fa_output, rest_extend[0]) if return_softmax_lse else fa_output
+
+    bs = seqused_k.size(0)
+    total_q = q.shape[0]
+    if max_seqlen_q == 1 or is_mtp:
+        assert not use_alibi_sqrt and qq_bias is None and s_aux is None and mm_prefix_range is None, \
+            f"Arguments not supported in hg_bshd_decode"
+        bshd_pa_decode = _require_hg_varlen_symbol("hg_prefix_decode_varlen_fwd")
+        result = bshd_pa_decode(
+            q,
+            k,
+            v,
+            out,
+            cu_seqlens_q,
+            None,
+            seqused_k,
+            alibi_slopes,
+            block_table,
+            max_seqlen_q,
+            max_seqlen_k,
+            0.0,
+            softmax_scale,
+            False,
+            causal,
+            window_size[0],
+            window_size[1],
+            softcap,
+            return_softmax_lse,
+            1,
+            None if (k_dtype_bits == 16) else q_descale,
+            None if (k_dtype_bits == 16) else k_descale,
+            None if (k_dtype_bits == 16) else v_descale,
+            True,
+        )
+        fa_output = result[0]
+        return (fa_output, result[1]) if return_softmax_lse else fa_output
+
     out, softmax_lse = flash_attn_cuda.varlen_fwd_unified(
         q,
         k,
@@ -3816,22 +3900,6 @@ def spas_fa2_attn_meansim_topk_varlen_cuda(
     )
 
 
-def fwd_sparse_mean_pool_fast(x,BLK,mean=None):
-    return flash_attn_cuda.fwd_sparse_mean_pool_fast(x,BLK,mean)
-
-def get_block_map_fast(q, k, topk_ratio, BLKQ=128, BLKK=64):
-    meank = torch.mean(k, dim=-3, keepdim=True)
-    pooled_kblocks = fwd_sparse_mean_pool_fast(k, BLKK, meank)
-    pooled_qblocks = fwd_sparse_mean_pool_fast(q,BLKQ)
-    pooled_score = pooled_qblocks @ pooled_kblocks.transpose(-1, -2)
-    K = pooled_score.shape[-1]
-    topk = min(K, int(topk_ratio * K))
-    lut = torch.topk(pooled_score, topk, dim=-1, sorted=False).indices
-    sparse_map = torch.zeros_like(pooled_score, dtype=torch.int8)
-    sparse_map.scatter_(-1, lut, 1)
-    return sparse_map, lut, topk
-    
-    
 class SparseLinearAttention(nn.Module):
     def __init__(self, head_dim, topk, feature_map='softmax', use_bf16=True, use_fp8=False, tie_feature_map_qk=True):
         R'''
@@ -3888,15 +3956,19 @@ class SparseLinearAttention(nn.Module):
         '''
         
         B, seqlen_q, H, headdim = q.shape
+        q_bhld = q.transpose(1, 2).contiguous()  # (B, H, L, D)
+        k_bhld = k.transpose(1, 2).contiguous()
+        # v_bhld = v.transpose(1, 2).contiguous()
+
+        # import pdb
+        # pdb.set_trace()
+        
         if headdim == 64:
             block_m = 64 if seqlen_q <= 2048 else 128
         elif headdim == 128:
             block_m = 64 if seqlen_q <= 2048 else 128
         block_k = 64 
-        if headdim == 64:
-            sparse_map, lut, real_topk = get_block_map(q.transpose(1, 2).contiguous(), k.transpose(1, 2).contiguous(), topk_ratio=self.topk, BLKQ=block_m, BLKK=block_k)
-        else:
-            sparse_map, lut, real_topk = get_block_map_fast(q, k, topk_ratio=self.topk, BLKQ=block_m, BLKK=block_k)
+        sparse_map, lut, real_topk = get_block_map(q_bhld, k_bhld, topk_ratio=self.topk, BLKQ=block_m, BLKK=block_k)
         
         q = q.to(self.dtype)
         k = k.to(self.dtype)
@@ -3912,10 +3984,10 @@ class SparseLinearAttention(nn.Module):
         seqlen_k = k.size(1)
         num_blocks_q = (seqlen_q + block_m - 1) // block_m
         num_blocks_k = (seqlen_k + block_k - 1) // block_k
-        column_count = torch.empty(
+        column_count = torch.zeros(
             (B, H, num_blocks_q), dtype=torch.int32, device=q.device
         )
-        column_index = torch.empty(
+        column_index = torch.zeros(
             (B, H, num_blocks_q, 1), dtype=torch.int32, device=q.device
         )
 
@@ -3984,56 +4056,14 @@ def sparse_attn_with_sla(
     
     maybe_contiguous = lambda x: x.contiguous() if x is not None and x.stride(-1) != 1 else x
     q, k, v = [maybe_contiguous(x) for x in (q, k, v)]
-    dtype = torch.bfloat16 if use_bf16 else torch.float16
-    dtype = torch.float8_e4m3fn if use_fp8 else dtype
-    B, seqlen_q, H, headdim = q.shape
-    assert not (use_bf16 and use_fp8), "Only one of bf16 and fp8 can be used."
-    assert headdim in (64, 128), "Dtype fp16/bf16 only support dim (64, 128)."
-    assert not (use_fp8 and headdim==64), "Dtype fp8 only support dim 128."
-    if headdim == 64:
-        block_m = 64 if seqlen_q <= 2048 else 128
-    elif headdim == 128:
-        block_m = 64 if seqlen_q <= 2048 else 128
-    block_k = 64 
-    if headdim == 64:
-        sparse_map, lut, real_topk = get_block_map(q.transpose(1, 2).contiguous(), k.transpose(1, 2).contiguous(), topk_ratio=topk, BLKQ=block_m, BLKK=block_k)
-    else:
-        sparse_map, lut, real_topk = get_block_map_fast(q, k, topk_ratio=topk, BLKQ=block_m, BLKK=block_k)
-    
-    q = q.to(dtype)
-    k = k.to(dtype)
-    v = v.to(dtype)
-
-    ########## SPARGE BEGIN ##########
-    headdim = q.size(-1)
-    block_offset, block_count = block_map_to_block_offset_triton(sparse_map)
-    block_offset = block_offset * block_k
-    softmax_scale = 1.0 / (headdim ** 0.5)
-    assert headdim in [64, 128], "headdim should be in [64, 128]. For other headdim, you can use padding and specify the softmax scale."
-
-    seqlen_k = k.size(1)
-    num_blocks_q = (seqlen_q + block_m - 1) // block_m
-    num_blocks_k = (seqlen_k + block_k - 1) // block_k
-    column_count = torch.empty(
-        (B, H, num_blocks_q), dtype=torch.int32, device=q.device
-    )
-    column_index = torch.empty(
-        (B, H, num_blocks_q, 1), dtype=torch.int32, device=q.device
-    )
-    o_s = sparse_attn_func(
-        q, k, v,  # Use original BLHD layout
-        block_count=block_count,
-        block_offset=block_offset,
-        column_count=column_count,
-        column_index=column_index,
-        softmax_scale=softmax_scale,
-        is_sla=True,
-    )
-
-    if return_sparsity:
-        return o_s, real_topk / sparse_map.shape[-1]
-    else:
-        return o_s
+    attn = SparseLinearAttention(
+        head_dim=q.size(-1),
+        topk=topk,                 # = 1 - sparsity
+        feature_map=feature_map,    # options: elu, relu, softmax
+        use_bf16=use_bf16,
+        use_fp8=use_fp8,
+    ).cuda()
+    return attn(q, k, v, return_sparsity=return_sparsity)
 
 
 def _require_hg_varlen_symbol(name: str):
@@ -4045,15 +4075,6 @@ def _require_hg_varlen_symbol(name: str):
     return symbol
 
 
-def _apply_hg_kvcache_safe_env() -> None:
-    # DTK/gfx938 PA launch is sensitive to these knobs. Keep the old HG-safe
-    # defaults unless the caller explicitly asks for the raw kernel selection.
-    if os.environ.get("HG_KVCACHE_RAW_KERNEL") == "1":
-        return
-    os.environ.setdefault("PA_NO_MLS", "1")
-    os.environ.setdefault("PA_USE_TILE32X32", "1")
-
-
 def _validate_hg_paged_kv_contract(k_cache, v_cache) -> None:
     if k_cache.dim() != 4 or v_cache.dim() != 4:
         raise ValueError("HG paged KV cache expects k and v to both be 4D tensors")
@@ -4067,53 +4088,6 @@ def _validate_hg_paged_kv_contract(k_cache, v_cache) -> None:
         )
 
 
-def _normalize_hg_paged_q_scales(q_scale, batch_size, num_heads_q, num_heads_k):
-    if q_scale is None:
-        raise ValueError("q_descale must be provided for HG int8 paged-kvcache path")
-    q_scale = maybe_contiguous(q_scale)
-    if q_scale.dim() == 1:
-        if q_scale.numel() == batch_size * num_heads_q:
-            q_scale = q_scale.view(batch_size, num_heads_q)
-        elif q_scale.numel() == batch_size * num_heads_k:
-            q_scale = q_scale.view(batch_size, num_heads_k)
-    if q_scale.dim() != 2 or q_scale.shape[0] != batch_size:
-        raise ValueError(
-            "q_descale must have shape [batch_size, num_heads_q] "
-            "or [batch_size, num_heads_k] for HG int8 paged-kvcache path"
-        )
-    if q_scale.shape[1] == num_heads_q:
-        return q_scale.contiguous()
-    if q_scale.shape[1] == num_heads_k and num_heads_q % num_heads_k == 0:
-        return q_scale.repeat_interleave(num_heads_q // num_heads_k, dim=1).contiguous()
-    raise ValueError(
-        "q_descale must have shape [batch_size, num_heads_q] "
-        "or [batch_size, num_heads_k] for HG int8 paged-kvcache path"
-    )
-
-
-def _expand_hg_paged_kv_scales(scale, block_table, page_block_size, num_heads_k, name):
-    if scale is None:
-        raise ValueError(f"{name} must be provided for HG int8 paged-kvcache path")
-    scale = maybe_contiguous(scale)
-    batch_size = block_table.shape[0]
-    if scale.dim() == 1 and scale.numel() == batch_size * num_heads_k:
-        scale = scale.view(batch_size, num_heads_k)
-    if scale.dim() != 2 or scale.shape != (batch_size, num_heads_k):
-        raise ValueError(
-            f"{name} must have shape [batch_size, num_heads_k] for HG int8 paged-kvcache path"
-        )
-    expanded = torch.empty(
-        (int(block_table.max().item()) + 1, page_block_size, num_heads_k),
-        device=scale.device,
-        dtype=scale.dtype,
-    )
-    for batch_idx in range(batch_size):
-        block_ids = block_table[batch_idx].to(dtype=torch.long)
-        expanded[block_ids] = scale[batch_idx].view(1, 1, num_heads_k).expand(
-            block_ids.numel(), page_block_size, num_heads_k
-        )
-    return expanded.contiguous()
-
 def hg_flash_attn_varlen_func(
     q,
     k,
@@ -4333,10 +4307,6 @@ def hg_flash_attn_varlen_func(
         raise ValueError("cu_seqlens_k and seqused_k cannot be provided at the same time")
     if block_table is None:
         raise ValueError("block_table must be provided when seqused_k is used")
-    if return_attn_probs:
-        raise NotImplementedError(
-            "return_attn_probs is not supported for HG prefix/paged compatibility paths"
-        )
     if dropout_p != 0.0:
         raise NotImplementedError("dropout_p must be 0.0 for HG prefix/paged compatibility paths")
 
@@ -4366,7 +4336,7 @@ def hg_flash_attn_varlen_func(
             window_size[0],
             window_size[1],
             softcap,
-            return_softmax_lse,
+            return_softmax_lse or return_attn_probs,
             1,
             None if k_dtype_bits == 16 else q_descale,
             None if k_dtype_bits == 16 else k_descale,
@@ -4374,7 +4344,7 @@ def hg_flash_attn_varlen_func(
             is_bf16_output,
         )
         fa_output = result[0]
-        return (fa_output, result[1]) if return_softmax_lse else fa_output
+        return (fa_output, result[1]) if (return_softmax_lse or return_attn_probs) else fa_output
 
     if k_dtype_bits == 16:
         prefix_decode = _require_hg_varlen_symbol("hg_prefix_decode_varlen_fwd")
@@ -4397,13 +4367,17 @@ def hg_flash_attn_varlen_func(
             window_size[0],
             window_size[1],
             softcap,
-            return_softmax_lse,
+            return_softmax_lse or return_attn_probs,
             1,
+            None,
+            None,
+            None,
+            is_bf16_output,
         )
         fa_output = result[0]
-        return (fa_output, result[1]) if return_softmax_lse else fa_output
+        return (fa_output, result[1]) if (return_softmax_lse or return_attn_probs) else fa_output
 
-    if return_softmax_lse:
+    if return_softmax_lse or return_attn_probs:
         raise NotImplementedError(
             "return_softmax_lse is not supported for the HG paged-kvcache compatibility path"
         )
@@ -4411,28 +4385,6 @@ def hg_flash_attn_varlen_func(
     _validate_hg_paged_kv_contract(k, v)
     if k.shape[1] != 128:
         raise NotImplementedError("HG paged-kvcache path currently requires page_block_size == 128")
-    _apply_hg_kvcache_safe_env()
-    q_descale = _normalize_hg_paged_q_scales(
-        q_descale,
-        batch_size=block_table.shape[0],
-        num_heads_q=q.shape[1],
-        num_heads_k=k.shape[2],
-    )
-    k_descale = _expand_hg_paged_kv_scales(
-        k_descale,
-        block_table=block_table,
-        page_block_size=k.shape[1],
-        num_heads_k=k.shape[2],
-        name="k_descale",
-    )
-    v_descale = _expand_hg_paged_kv_scales(
-        v_descale,
-        block_table=block_table,
-        page_block_size=v.shape[1],
-        num_heads_k=v.shape[2],
-        name="v_descale",
-    )
-
     hg_kvcache = _require_hg_varlen_symbol("hg_fwd_kvcache_bshd")
     result = hg_kvcache(
         q.unsqueeze(1),
@@ -4442,7 +4394,7 @@ def hg_flash_attn_varlen_func(
         None,
         None,
         seqused_k,
-        max_seqlen_k if max_seqlen_k > 0 else int(seqused_k.max().item()),
+        1,
         None,
         None,
         None,
@@ -4456,12 +4408,12 @@ def hg_flash_attn_varlen_func(
         window_size[1],
         softcap,
         False,
-        num_splits,
+        -1,
         None,
         None,
-        q_descale,
-        k_descale,
-        v_descale,
+        None if k_dtype_bits == 16 else q_descale,
+        None if k_dtype_bits == 16 else k_descale,
+        None if k_dtype_bits == 16 else v_descale,
         is_bf16_output,
     )
     return result[0].squeeze(1)

setup.py

@@ -112,6 +112,8 @@ _HG_EXPLICIT_SOURCES_BY_MODE = {
         "src/target/flash_fwd_hdim128_padding_mask_fp16.cpp",
         "src/target/flash_fwd_hdim128_prefix_prefill_bf16.cpp",
         "src/target/flash_fwd_hdim128_prefix_prefill_fp16.cpp",
+        "src/target/flash_fp8_fwd_hdim128_prefix_prefill_bf16.cpp",
+        "src/target/flash_fp8_fwd_hdim128_prefix_prefill_fp16.cpp",
         "src/target/flash_fwd_hdim160_bf16.cpp",
         "src/target/flash_fwd_hdim160_fp16.cpp",
         "src/target/flash_fwd_hdim192_bf16.cpp",
@@ -262,6 +264,32 @@ def _ninja_shell_join(args) -> str:
     return " ".join(_ninja_escape(shlex.quote(str(x))) for x in args)
 
 
+def _resolve_hg_compiler() -> str:
+    candidates = [
+        os.environ.get("FLASH_ATTN_HG_COMPILER"),
+        "/opt/dtk/bin/aicc",
+        "aicc",
+    ]
+    for compiler in candidates:
+        if compiler and shutil.which(compiler):
+            return compiler
+    requested = [c for c in candidates if c]
+    raise RuntimeError(
+        "error: no usable HG aicc compiler found from: "
+        + ", ".join(repr(c) for c in requested)
+        + ". Set FLASH_ATTN_HG_COMPILER to the DTK aicc path."
+    )
+
+
+def _is_rocm_5_7() -> bool:
+    version_file = "/opt/rocm/.info/version"
+    try:
+        with open(version_file, "r", encoding="utf-8") as f:
+            return f.read(100).startswith("5.7.0")
+    except OSError:
+        return False
+
+
 def compute_hg_build_descriptor(
     src_dir,
     build_dir,
@@ -279,7 +307,7 @@ def compute_hg_build_descriptor(
     BUILD_FA_FWD = BUILD_FA_BWD = BUILD_FA_KVCACHE = False
     BUILD_FA_PERMUTE = BUILD_FLASHMLA = False
     BUILD_C_INTERFACE = False
-    BUILD_ASM = False
+    BUILD_ASM = True
     FA_DEBUG = True
     FA_DEBUG_SUM_MAX = False
     HEADDIM_128_ONLY = False
@@ -358,11 +386,8 @@ def compute_hg_build_descriptor(
         GFX_VERSION = "938"
 
     ROCM_PATH = os.environ.get("ROCM_PATH", os.environ.get("ROCM_HOME", "/opt/rocm"))
+    HG_COMPILER = _resolve_hg_compiler()
 
-    if not shutil.which("hipcc"):
-        raise RuntimeError(
-            "error: hipcc not found in PATH. Please activate the DTK environment first."
-        )
     if not os.path.isdir(os.path.join(ROCM_PATH, "include")):
         raise RuntimeError(
             f"error: {ROCM_PATH}/include not found. "
@@ -444,6 +469,8 @@ def compute_hg_build_descriptor(
         DEFINES.append("-DPA_PAGE_BLOCK_SIZE")
     if MLA_PAGE_BLOCK_SIZE:
         DEFINES.append("-DMLA_PAGE_BLOCK_SIZE")
+    if _is_rocm_5_7():
+        DEFINES.append("-DROCM_5_7")
 
     OFFLOAD_FLAGS = [f"--offload-arch=gfx{_g}" for _g in GFX_VERSION.split(";") if _g]
 
@@ -457,23 +484,29 @@ def compute_hg_build_descriptor(
         INCLUDE_FLAGS += TORCH_INCLUDE_FLAGS
 
     COMMON_FLAGS = [
+        "-fPIC",
         "-O3",
         "-std=c++17",
-        "-fPIC",
         "-ffast-math",
         "-fno-finite-math-only",
         "-fno-gpu-rdc",
-        "-mno-fma",
     ]
     DTK_DEVICE_FLAGS = [
-        "-DHIP_ENABLE_WARP_SYNC_BUILTINS",
         "-mllvm",
-        "-slp-phi-tree-bb-max-size=10000",
+        "-support-768-vgprs=true",
         "-mllvm",
-        "-enable-num-vgprs-512=true",
-        "-Rpass-analysis=kernel-resource-usage",
-        "-ftemplate-backtrace-limit=0",
+        "-disable-machine-sink",
+        "-mcode-object-version=5",
     ]
+    if not _is_rocm_5_7():
+        DTK_DEVICE_FLAGS += [
+            "-mllvm",
+            "-amdgpu-enable-rewrite-partial-reg-uses=false",
+            "-mllvm",
+            "-allow-gvn-convergent-call=true",
+            "-mllvm",
+            "-disallow-uniform-vmed3-combine=true",
+        ]
     if os.environ.get("FLASH_ATTN_HG_SAVE_TEMPS", "") == "1":
         DTK_DEVICE_FLAGS.append("--save-temps")
 
@@ -555,6 +588,7 @@ def compute_hg_build_descriptor(
         "obj_dir": obj_dir,
         "sources": _all_sources,
         "objects": objects,
+        "compiler": HG_COMPILER,
         "compile_flags": compile_flags,
         "link_flags": link_flags,
         "out_so": out_so,
@@ -566,16 +600,17 @@ def run_hg_ninja_build(descriptor: dict) -> None:
     """Write build_hg.ninja and run ninja (parallel via MAX_JOBS)."""
     build_dir = descriptor["build_dir"]
     ninja_file = descriptor["ninja_path"]
+    compiler = _ninja_shell_join([descriptor["compiler"]])
     out_so_ninja = _ninja_escape_path(descriptor["out_so"])
     lines = [
         "ninja_required_version = 1.3",
         "",
-        "rule hipcc_compile",
-        "  command = hipcc -c $in -o $out $FLAGS",
+        "rule hg_compile",
+        f"  command = {compiler} -c $in -o $out $FLAGS",
         "  description = HG compile $in",
         "",
-        "rule hipcc_link",
-        "  command = hipcc -shared -o $out @$out.rsp $LINK_FLAGS",
+        "rule hg_link",
+        f"  command = {compiler} -shared -o $out @$out.rsp $LINK_FLAGS",
         "  rspfile = $out.rsp",
         "  rspfile_content = $in",
         "  description = HG link $out",
@@ -585,9 +620,9 @@ def run_hg_ninja_build(descriptor: dict) -> None:
         "",
     ]
     for src, obj in zip(descriptor["sources"], descriptor["objects"]):
-        lines.append(f"build {_ninja_escape_path(obj)}: hipcc_compile {_ninja_escape_path(src)}")
+        lines.append(f"build {_ninja_escape_path(obj)}: hg_compile {_ninja_escape_path(src)}")
     obj_list = " ".join(_ninja_escape_path(obj) for obj in descriptor["objects"])
-    lines.append(f"build {out_so_ninja}: hipcc_link {obj_list}")
+    lines.append(f"build {out_so_ninja}: hg_link {obj_list}")
     lines.append("")
 
     os.makedirs(build_dir, exist_ok=True)
@@ -878,7 +913,6 @@ if not SKIP_CUDA_BUILD:
                 "csrc/flash_attn/src/flash_fwd_unified_hdim256_fp16_sm80.cu",
                 "csrc/flash_attn/src/flash_fwd_unified_hdim256_bf16_causal_sm80.cu",
                 "csrc/flash_attn/src/flash_fwd_unified_hdim256_bf16_sm80.cu",
-                "csrc/flash_attn/src/flash_sparse_util.cu"
             ],
             extra_compile_args={
                 "cxx": ["-O3", "-w", "-std=c++17",
@@ -944,6 +978,7 @@ if not SKIP_CUDA_BUILD:
                 Path(this_dir) / "csrc" / "flash_attn",
                 Path(this_dir) / "csrc" / "flash_attn" / "src",
                 Path(this_dir) / "csrc" / "cutlass" / "include",
+                "/public/home/huangly/数据采集/cutlass_3.2.1/include"            ],
         )
     )
 
@@ -1051,13 +1086,16 @@ class NinjaBuildExtension(BuildExtension):
             if os.path.isdir(HG_SRC_DIR):
                 os.makedirs(HG_BUILD_DIR, exist_ok=True)
                 _maybe_clean_hg_build_dir(HG_BUILD_DIR)
-                print("=== Building HG libflash_attention.so (mode=all, gfx938, ninja) ===")
                 try:
                     desc = compute_hg_build_descriptor(
                         HG_SRC_DIR,
                         HG_BUILD_DIR,
                         mode="all",
-                        extra_options_raw="-DGFX_VERSION=938 -Wl,-Bsymbolic",
+                        extra_options_raw="-DGFX_VERSION=938;936 -Wl,-Bsymbolic",
+                    )
+                    print(
+                        "=== Building HG libflash_attention.so "
+                        f"(mode=all, gfx938/936, ninja, compiler={desc['compiler']}) ==="
                     )
                     run_hg_ninja_build(desc)
                     if os.path.isfile(HG_SO_BUILD):

tests/prefix_decode_sglang_decode.py

+import os
+import sys
+import math
+import torch
+import pickle
+import time
+import numpy
+import argparse
+import random
+from datetime import datetime
+use_cuda_toolkits = os.path.exists("/usr/local/cuda/bin/nvcc")
+use_rocm_toolkits = os.path.exists("/opt/rocm/llvm/bin/clang")
+use_dtk_toolkits = os.path.exists("/opt/dtk/bin/aicc")
+if (use_cuda_toolkits):
+    from vllm.vllm_flash_attn import flash_attn_varlen_func
+elif (use_rocm_toolkits or use_dtk_toolkits):
+    try:
+        from flash_attention_interface import flash_attn_varlen_func, flash_attn_2_cuda, flash_attn_with_kvcache
+    except ModuleNotFoundError:
+        from flash_attn.flash_attn_interface import flash_attn_varlen_func, flash_attn_with_kvcache
+
+import flash_attn_2_cuda as flash_attn_cuda
+
+def _require_hg_varlen_symbol(name: str):
+    symbol = getattr(flash_attn_cuda, name, None)
+    if symbol is None:
+        raise RuntimeError(
+            f"{name} is unavailable in this build. Rebuild flash_attn with HAS_HG_DISPATCH enabled."
+        )
+    return symbol
+
+def cal_diff(x: torch.Tensor, y: torch.Tensor, name: str, do_assert=True, cos_threshold=1e-5) -> None:
+    assert x.shape == y.shape, "for {}, x and y must have the same shape".format(name)
+    x, y = x.double(), y.double()
+    RMSE = ((x - y) * (x - y)).mean().sqrt().item()
+    cos_diff = 1 - 2 * (x * y).sum().item() / max((x * x + y * y).sum().item(), 1e-12)
+    amax_diff = (x - y).abs().max().item()
+    rel_diff_mean = (x / y).abs().mean().item()
+    rel_diff_max  = (x / y).abs().max().item()
+    print("name:{} cos_diff={:.12f}, RMSE=\x1b[35m{:.12f}\x1b[0m, amax_diff=\x1b[35m{:.12f}\x1b[0m, REL=\x1b[35m{:.12f}\x1b[0m, rel_max=\x1b[35m{:.12f}\x1b[0m".format(
+        name, cos_diff, RMSE, amax_diff, rel_diff_mean, rel_diff_max))
+    if (do_assert): assert cos_diff < cos_threshold
+
+
+def scaled_dot_product_attention(__query, __key, __value, h_q, h_kv, is_causal=False, USE_CPU=False, return_max_sum=False, original_seqlen_kv=0, split_slice=0, is_bshd=False, window_size=(-1, -1)):
+    __query = __query.transpose(0, 1).contiguous()
+    __key = __key.transpose(0, 1).contiguous()
+    __value = __value.transpose(0, 1).contiguous()
+    # 判断是否使用 CPU 计算 golden, 避免 blas 的影响
+    original_device = __query.device
+    original_dtype  = __query.dtype
+    if (USE_CPU):
+        __query = __query.cpu()
+        __key   = __key.cpu()
+        __value = __value.cpu()
+    # print("scaled_dot_product_attention: ", query.shape, key.shape, value.shape)
+    __query = __query.float()
+    __key   = __key.float()
+    __value = __value.float()
+    # 如果按照官方的方法返回
+    if (not return_max_sum):
+        __key   = __key.repeat_interleave(h_q // h_kv, dim=0)
+        __value = __value.repeat_interleave(h_q // h_kv, dim=0)
+        attn_weight = __query @ __key.transpose(-2, -1) / math.sqrt(__query.size(-1))
+        # MTP > 1, causal/local mask applied
+        if (window_size != (-1, -1)):
+            s_q = __query.shape[-2]
+            s_k = __key.shape[-2]
+            left, right = window_size
+            if left < 0:
+                left = s_k
+            if right < 0:
+                right = s_k
+            row_idx = torch.arange(s_q, dtype=torch.int32, device=attn_weight.device)[:, None]
+            col_idx = torch.arange(s_k, dtype=torch.int32, device=attn_weight.device)[None, :]
+            col_idx_limit_left = row_idx + s_k - s_q - left
+            col_idx_limit_right = row_idx + s_k - s_q + right
+            temp_mask = (col_idx >= col_idx_limit_left) & (col_idx <= col_idx_limit_right)
+            attn_weight = attn_weight.masked_fill(temp_mask.logical_not(), float("-inf"))
+        elif (is_causal):
+            s_q = __query.shape[-2]
+            s_k = __key.shape[-2]
+            attn_bias = torch.zeros(s_q, s_k, dtype=__query.dtype, device=attn_weight.device)
+            temp_mask = torch.ones(s_q, s_k, dtype=torch.bool, device=attn_weight.device).tril(diagonal=s_k - s_q)
+            attn_bias.masked_fill_(temp_mask.logical_not(), float("-inf"))
+            attn_bias.to(__query.dtype)
+            attn_weight += attn_bias
+        # some codes for debug
+        scores_max = attn_weight.to(torch.float32).max(-1)[0]
+        scores_sum = torch.exp(attn_weight.to(torch.float32) - scores_max.unsqueeze(-1)).sum(dim=-1)
+        # original codes
+        lse = attn_weight.logsumexp(dim=-1)
+        attn_weight = torch.softmax(attn_weight, dim=-1, dtype=torch.float32)
+        output = attn_weight @ __value
+        output = output.transpose(0, 1).contiguous()
+        return output.to(original_device).to(original_dtype), lse.to(original_device), scores_max.to(original_device), scores_sum.to(original_device)
+
+
+def set_random_seed(seed=0):
+    random.seed(seed)  # 设置 Python 的随机种子
+    numpy.random.seed(seed)  # 设置 NumPy 的随机种子
+    torch.manual_seed(seed)  # 设置 PyTorch 的随机种子
+    if torch.cuda.is_available():
+        torch.cuda.manual_seed_all(seed)  # 设置所有 GPU 的随机种子
+        torch.backends.cudnn.deterministic = True
+        torch.backends.cudnn.benchmark = False
+    os.environ['OMP_NUM_THREADS'] = '1'  # 设置 OpenMP 的线程数
+    torch.set_num_threads(1)  # 设置 PyTorch 的线程数
+
+
+if __name__ == '__main__':
+
+    parser = argparse.ArgumentParser(description='Process some integers.')
+    parser.add_argument('--load', default=False, action='store_true', help='load path')
+    parser.add_argument('--trace', default=False, action='store_true', help='whether dump perf traces')
+    parser.add_argument('--bf16', default=False, action='store_true', help='whether use bfloat16 as main dtype')
+    parser.add_argument('--fp8', default=False, action='store_true', help='whether use fp8_e4m3 inputs for HG decode')
+    parser.add_argument('--pressure', default=False, action='store_true', help='whether do pressure test')
+    parser.add_argument('--cpu', default=False, action='store_true', help='whether compute golden via cpu')
+    parser.add_argument('--pad', default=False, action='store_true', help='whether make query uncontiguous to simulate vllm behaviors')
+    parser.add_argument('--iterations', type=int, default=100, help='pressure test times')
+    parser.add_argument('--block_size', type=int, default=128, help='page block_size')
+    parser.add_argument('--batch-size', type=int, default=1, help='batch size for generated inputs')
+    parser.add_argument('--seq-q', type=int, default=4, help='query length per batch for generated inputs')
+    parser.add_argument('--seq-k', type=int, default=2048, help='kv length per batch for generated inputs')
+    parser.add_argument('--num-heads', type=int, default=24, help='number of query heads for generated inputs')
+    parser.add_argument('--num-heads-kv', type=int, default=2, help='number of kv heads for generated inputs')
+    parser.add_argument('--no-causal', dest='causal', default=True, action='store_false', help='disable causal mask for generated inputs')
+    parser.add_argument('--window-left', type=int, default=-1, help='left sliding window size')
+    parser.add_argument('--window-right', type=int, default=-1, help='right sliding window size')
+    parser.add_argument('--seed', default=False, action='store_true', help='whether do pressure test')
+    args = parser.parse_args()
+
+    if (args.seed):
+        set_random_seed(212)
+
+    # 从文件加载输入
+    if (args.load):
+        nvidia_packet = torch.load("./demo.pt")
+        query, key, value, cu_seqlens_q, max_seqlen_q, cache_seqlens, max_seqlen_k, softmax_scale, causal, window_size, alibi_slopes, page_table, softcap, fa_version, q_descale, k_descale, v_descale = nvidia_packet["inputs"]
+        vllm_golden = nvidia_packet["outputs"]
+        # 解析出必要的参数
+        batch_size = page_table.shape[0]
+        assert batch_size == cu_seqlens_q.shape[0] - 1, "check batch size"
+        page_block_size = key.shape[1]
+        num_heads_kv = key.shape[2]
+        num_heads    = query.shape[1]
+        head_dim_qk  = query.shape[2]
+        head_dim_v   = key.shape[3]
+        infer_dtype  = query.dtype
+    else:
+        # 随机生成 seqkv
+        batch_size = args.batch_size
+
+        # 得到 Q 的长度
+        seqlen_q = [args.seq_q for i in range(batch_size)]
+        seqlen_q_sum = sum(seqlen_q)
+        max_seqlen_q = max(seqlen_q)
+        cu_seqlens_q = numpy.array([0] + numpy.cumsum(seqlen_q).tolist()).astype("int32")
+        cu_seqlens_q = torch.from_numpy(cu_seqlens_q)
+
+        # 得到 KV 的长度
+        cache_seqlens  = [args.seq_k for i in range(batch_size)]
+
+        # 指定分页块的大小, nvidia 64, ours 128
+        page_block_size = 16 if (use_cuda_toolkits) else args.block_size
+
+        # 根据分页块大小计算实际需要的页表的大小
+        max_seqlen_k = max(cache_seqlens)
+        seqlen_kv_real_required_page = [math.ceil(it / page_block_size) for it in cache_seqlens]
+        seqlen_kv_real_required_page_sum = sum(seqlen_kv_real_required_page)
+        # 默认按照最大 seqlenkv 的来分配
+        seqlen_kv_max_required_page = math.ceil(max_seqlen_k / page_block_size)
+        seqlen_kv_max_required_page_total = batch_size * seqlen_kv_max_required_page
+        # 打乱页表
+        shuffle = True
+        if (shuffle):
+            block_random = torch.randperm(seqlen_kv_max_required_page_total, dtype=torch.int32, device="cuda")
+        else:
+            block_random = torch.arange(seqlen_kv_max_required_page_total , dtype=torch.int32)
+        page_table    = []
+        seq_block_incre = 0
+        for i in range(batch_size):
+            blocks_pad = [0] * seqlen_kv_max_required_page
+            if (shuffle):
+                blocks_pad[:seqlen_kv_real_required_page[i]] = block_random[seq_block_incre: seq_block_incre + seqlen_kv_real_required_page[i]].cpu().tolist()
+                seq_block_incre += seqlen_kv_real_required_page[i]
+            else:
+                blocks_pad = block_random[seq_block_incre: seq_block_incre + seqlen_kv_max_required_page].cpu().tolist()
+                seq_block_incre += seqlen_kv_max_required_page
+            page_table.append(torch.IntTensor(blocks_pad))
+        page_table = torch.stack(page_table).contiguous().to("cuda")
+        # 创建基本参数
+        head_dim_qk   = 128
+        head_dim_v    = 128
+        num_heads     = args.num_heads
+        num_heads_kv  = args.num_heads_kv
+        infer_dtype   = torch.float16 # deepseek 默认使用 bfloat16 推理
+        if (args.bf16): infer_dtype = torch.bfloat16 # 除非命令行指定用 fp16, 不受 args.dtype 影响
+        softmax_scale = 1.0 / math.sqrt(head_dim_qk)
+        causal        = args.causal
+        window_size   = (args.window_left, args.window_right)
+        alibi_slopes  = None
+        softcap       = 0.0
+        fa_version    = 2
+        q_descale     = torch.ones((batch_size, num_heads), dtype=torch.float32, device="cuda")
+        k_descale     = torch.ones((batch_size, num_heads_kv), dtype=torch.float32, device="cuda")
+        v_descale     = torch.ones((batch_size, num_heads_kv), dtype=torch.float32, device="cuda")
+
+        # 创建输入张量
+        if (args.pad):
+            query_origin_tensor = torch.randn((seqlen_q_sum, num_heads + 16, head_dim_qk), dtype=infer_dtype, device="cuda")
+            q = query_origin_tensor[:, :num_heads]
+        else:
+            q = torch.randn((seqlen_q_sum, num_heads, head_dim_qk), dtype=infer_dtype, device="cuda")
+        k_cache   = torch.randn((seqlen_kv_max_required_page_total, page_block_size, num_heads_kv, head_dim_qk), device="cuda", dtype=infer_dtype)
+        v_cache = torch.randn((seqlen_kv_max_required_page_total, page_block_size, num_heads_kv, head_dim_v), device="cuda", dtype=infer_dtype)
+        vllm_golden  = None
+        cu_seqlens_q = cu_seqlens_q.to(q.device)
+        cache_seqlens    = torch.from_numpy(numpy.array(cache_seqlens).astype("int32")).to(q.device)
+
+    q_ref = q
+    k_cache_ref = k_cache
+    v_cache_ref = v_cache
+    if args.fp8:
+        if not hasattr(torch, "float8_e4m3fn"):
+            raise RuntimeError("This PyTorch build does not support torch.float8_e4m3fn")
+        q = q.to(torch.float8_e4m3fn)
+        k_cache = k_cache.to(torch.float8_e4m3fn)
+        v_cache = v_cache.to(torch.float8_e4m3fn)
+        q_ref = q.to(infer_dtype)
+        k_cache_ref = k_cache.to(infer_dtype)
+        v_cache_ref = v_cache.to(infer_dtype)
+
+    # 展示一下输入数据
+    print("--------------------------------------------------------------------------------------------")
+    print("q: ", q.shape, q.dtype, q.is_contiguous(), q.stride())
+    print("k_cache: ", k_cache.shape, k_cache.dtype, k_cache.is_contiguous(), k_cache.stride())
+    print("v_cache: ", v_cache.shape, v_cache.dtype, v_cache.is_contiguous(), v_cache.stride())
+    print("cu_seqlens_q: ", cu_seqlens_q.shape, cu_seqlens_q.dtype, cu_seqlens_q.is_contiguous())
+    print("cu_seqlens_q: ", cu_seqlens_q)
+    print("max_seqlen_q: ", max_seqlen_q)
+    print("cache_seqlens: ", cache_seqlens)
+    print("max_seqlen_k: ", max_seqlen_k)
+    print("softmax_scale: ", softmax_scale)
+    print("causal: ", causal)
+    print("window_size: ", window_size)
+    print("alibi_slopes: ", alibi_slopes)
+    print("page_table: ", page_table.shape, page_table.dtype, page_table.is_contiguous(), page_table.stride())
+    print("page_table: ", page_table)
+    print("softcap: ", softcap)
+    print("fa_version: ", fa_version)
+    print("q_descale: ", q_descale.shape, q_descale.dtype, q_descale.tolist())
+    print("k_descale: ", k_descale.shape, k_descale.dtype, k_descale.tolist())
+    print("v_descale: ", v_descale.shape, v_descale.dtype, v_descale.tolist())
+
+    print("--------------------------------------------------------------------------------------------")
+    # 先从 kvcache 中还原出 key 和 value
+    key_original   = []
+    value_original = []
+    for b in range(batch_size):
+        # 获取页表索引
+        index = page_table[b]
+        # 获取实际的索引
+        max_page_blocks = math.ceil(cache_seqlens[b] / page_block_size)
+        actual_index = index[:max_page_blocks]
+        # 根据该页表索引获取当前 seqlenkv 的内容
+        key_content = k_cache_ref[actual_index]
+        # reshape 回去
+        key_content = key_content.view(-1, num_heads_kv, head_dim_qk)[:cache_seqlens[b]].contiguous()
+        # 同理
+        value_content = v_cache_ref[actual_index].view(-1, num_heads_kv, head_dim_v)[:cache_seqlens[b]].contiguous()
+        key_original.append(key_content)
+        value_original.append(value_content)
+
+    # 同理还原出 query 的内容
+    query_original = []
+    cum_q = 0
+    for b in range(batch_size):
+        query_len = cu_seqlens_q[b + 1] - cu_seqlens_q[b]
+        query_content = q_ref[cum_q: cum_q + query_len]
+        query_original.append(query_content.contiguous())
+        cum_q += query_len
+
+    # 重新实现 self-attention
+    golden = []
+    golden_lse = []
+    golden_max = []
+    for b in range(batch_size):
+        tmp_output, lse, scores_max, scores_sum = scaled_dot_product_attention(query_original[b], key_original[b], value_original[b], num_heads, num_heads_kv, is_causal=causal, USE_CPU=args.cpu, window_size=window_size)
+        golden.append(tmp_output)
+        golden_lse.append(lse)
+        golden_max.append(scores_max)
+    golden = torch.cat(golden, dim=0)
+    golden_lse = torch.cat(golden_lse, dim=-1)
+    golden_max = torch.cat(golden_max, dim=-1)
+    print("golden: ", golden.shape)
+    print("golden_lse: ", golden_lse.shape)
+    print("--------------------------------------------------------------------------------------------")
+    if (True):
+        # fa_output, fa_lse = flash_attn_2_cuda.prefix_decode_varlen_fwd(
+        bshd_pa_decode = _require_hg_varlen_symbol("hg_prefix_decode_varlen_fwd")
+        fa_output, fa_lse = bshd_pa_decode(
+            q,
+            k_cache,
+            v_cache,
+            None, # out_
+            cu_seqlens_q,
+            None, # cu_seqlens_k
+            cache_seqlens,
+            alibi_slopes,
+            page_table,
+            max_seqlen_q,
+            max_seqlen_k,
+            0.0, # dropout
+            softmax_scale,
+            False, # zero_tensors
+            causal,
+            window_size[0],
+            window_size[1],
+            softcap,
+            True, # return_softmax_lse,
+            1,
+            q_descale if args.fp8 else None,
+            k_descale if args.fp8 else None,
+            v_descale if args.fp8 else None,
+            infer_dtype == torch.bfloat16,
+        )
+    else:
+        fa_output, fa_lse, *rest = flash_attn_with_kvcache(
+            q=q,
+            k_cache=k_cache,
+            v_cache=v_cache,
+            page_table=page_table,
+            cache_seqlens=cache_seqlens,
+            cu_seqlens_q=cu_seqlens_q,
+            cu_seqlens_k_new=cache_seqlens,
+            max_seqlen_q=max_seqlen_q,
+            softmax_scale=softmax_scale,
+            causal=causal,
+            window_size=window_size,
+            softcap=softcap,
+            k_descale=k_descale,
+            v_descale=v_descale,
+            return_softmax_lse=True,
+        )
+    torch.cuda.synchronize()
+    if (vllm_golden is not None):
+        # 检查保存流程是否有错误
+        cal_diff(fa_output, vllm_golden, "check")
+
+    print("fa_output: ", fa_output.shape)
+    if (fa_lse is not None): print("fa_lse: ", fa_lse.shape)
+    # 检验精度如何
+    fp8_threshold = 5e-3
+    cal_diff(golden, fa_output, "accuracy", True, fp8_threshold if args.fp8 else 1e-5)
+    if (fa_lse is not None): cal_diff(golden_lse, fa_lse, "softmax_lse", True, fp8_threshold if args.fp8 else 1e-5)
+    print("--------------------------------------------------------------------------------------------")
+
+    # benchmark 性能数据
+    import triton
+    def benchmark_prefix_prefill():
+        _ = bshd_pa_decode(
+            q,
+            k_cache,
+            v_cache,
+            None,
+            cu_seqlens_q,
+            None,
+            cache_seqlens,
+            alibi_slopes,
+            page_table,
+            max_seqlen_q,
+            max_seqlen_k,
+            0.0,
+            softmax_scale,
+            False,
+            causal,
+            window_size[0],
+            window_size[1],
+            softcap,
+            True,
+            1,
+            q_descale if args.fp8 else None,
+            k_descale if args.fp8 else None,
+            v_descale if args.fp8 else None,
+            infer_dtype == torch.bfloat16,
+        )
+    # 适时关闭, 用于 debug
+    if ((os.getenv("FA_DEBUG") is None) and (os.getenv("HIP_LOG_LEVEL") is None) and not args.trace):
+        import triton
+        t = triton.testing.do_bench_cudagraph(benchmark_prefix_prefill)
+        FLOPS = float(0)
+        BYTES = float(0)
+        for b in range(batch_size):
+            batch_seqlen_q = cu_seqlens_q[b + 1] - cu_seqlens_q[b]
+            batch_seqlen_k = cache_seqlens[b]
+            undo_flops = batch_seqlen_q * batch_seqlen_q / 2 if (causal) else 0
+            qk_flops = num_heads * (batch_seqlen_q * batch_seqlen_k - undo_flops) * head_dim_qk * 2
+            pv_flops = num_heads * (batch_seqlen_q * batch_seqlen_k - undo_flops) * head_dim_v * 2
+            FLOPS += qk_flops + pv_flops
+            q_load = batch_seqlen_q * num_heads * head_dim_qk
+            k_load = batch_seqlen_k * num_heads_kv * head_dim_qk # k load not only once
+            v_load = batch_seqlen_k * num_heads_kv * head_dim_v
+            BYTES += q_load * q.element_size() + k_load * k_cache.element_size() + v_load * v_cache.element_size() # ignore storation ?
+        print(f"Performance: {t:.3f} ms, \x1b[35m{FLOPS / 10 ** 9 / t:.2f}\x1b[0m TFLOPS, \x1b[35m{BYTES / 10 ** 6 / t:.0f}\x1b[0m GB/s")
+
+        # 压力测试
+        if (args.pressure):
+            pressure_count = max(100, args.iterations)
+            for p in range(pressure_count):
+                pressure_fa_output = torch.zeros_like(fa_output)
+                pressure_fa_output, _ = bshd_pa_decode(
+                    q.clone(),
+                    k_cache.clone(),
+                    v_cache.clone(),
+                    None,
+                    cu_seqlens_q,
+                    None,
+                    cache_seqlens,
+                    alibi_slopes,
+                    page_table,
+                    max_seqlen_q,
+                    max_seqlen_k,
+                    0.0,
+                    softmax_scale,
+                    False,
+                    causal,
+                    window_size[0],
+                    window_size[1],
+                    softcap,
+                    True,
+                    1,
+                    q_descale if args.fp8 else None,
+                    k_descale if args.fp8 else None,
+                    v_descale if args.fp8 else None,
+                    infer_dtype == torch.bfloat16,
+                )
+                torch.cuda.synchronize()
+                is_equal = torch.equal(pressure_fa_output, fa_output)
+                if (not is_equal): cal_diff(pressure_fa_output, fa_output, "pressure")
+                assert is_equal, "\x1b[31mUnstable\x1b[0m!"
+                del pressure_fa_output
+                sys.stdout.write("\rPressure Test: {}/{}".format(p + 1, pressure_count))
+            print(" \x1b[32mPASS\x1b[0m")
+        print("-----------------------------------------------------------------------------------")

tests/test_unified_attn.py

 import torch
+import os
 
 from vllm.logger import init_logger
 from vllm.platforms import current_platform
@@ -6,6 +7,27 @@ from vllm.triton_utils import tl, triton
 
 import math
 import time
+
+
+def estimate_unified_attention_bytes(
+    batch_size,
+    seqlen_q,
+    seqlen_k,
+    nheads,
+    nheads_k,
+    d,
+    block_size,
+    q_bytes,
+    k_bytes,
+    v_bytes,
+    out_bytes=0,
+):
+    num_blocks = math.ceil(seqlen_k / block_size)
+    q_bytes_total = batch_size * seqlen_q * nheads * d * q_bytes
+    kv_bytes_total = seqlen_k * batch_size * nheads_k * d * (k_bytes + v_bytes)
+    out_bytes_total = batch_size * seqlen_q * nheads * d * out_bytes
+    metadata_bytes = (batch_size + 1) * 4 + batch_size * 4 + batch_size * num_blocks * 4
+    return q_bytes_total + kv_bytes_total + out_bytes_total + metadata_bytes
 import pytest
 import torch
 import torch.nn.functional as F
@@ -18,19 +40,19 @@ import pdb
 
 from einops import rearrange, repeat
 from flash_attn import (
-    flash_attn_func,
-    flash_attn_kvpacked_func,
-    flash_attn_qkvpacked_func,
-    flash_attn_varlen_func,
-    flash_attn_varlen_kvpacked_func,
-    flash_attn_varlen_qkvpacked_func,
-    flash_attn_with_kvcache,
+    # flash_attn_func,
+    # flash_attn_kvpacked_func,
+    # flash_attn_qkvpacked_func,
+    # flash_attn_varlen_func,
+    # flash_attn_varlen_kvpacked_func,
+    # flash_attn_varlen_qkvpacked_func,
+    # flash_attn_with_kvcache,
     varlen_fwd_unified,
 )
-from flash_attn import flash_attn_func
-from flash_attn.bert_padding import pad_input, unpad_input
-from flash_attn.flash_attn_interface import _get_block_size_n
-from flash_attn.layers.rotary import apply_rotary_emb
+# from flash_attn import flash_attn_func
+# from flash_attn.bert_padding import pad_input, unpad_input
+# from flash_attn.flash_attn_interface import _get_block_size_n
+# from flash_attn.layers.rotary import apply_rotary_emb
 
 MAX_HEADDIM_SM8x = 192
 
@@ -1245,60 +1267,102 @@ def cal_diff(x: torch.Tensor, y: torch.Tensor, name: str, use_fp8: bool = False,
     if is_e5m2:
         assert cos_diff < 1e-2
     elif use_fp8:
-        assert cos_diff < 1e-3
+        assert cos_diff < 5e-3
     else:
         assert cos_diff < (1e-4 if torch_dtype == torch.bfloat16 else 1e-5)
 
+class _NoUnifiedFallback:
+    def __init__(self, module):
+        self._module = module
+
+    def __getattr__(self, name):
+        if name == "varlen_fwd_unified":
+            raise AssertionError("unexpected fallback to flash_attn_cuda.varlen_fwd_unified")
+        return getattr(self._module, name)
+
+
+def varlen_fwd_unified_expect_hg(expected_symbol, *args, **kwargs):
+    fn_globals = varlen_fwd_unified.__globals__
+    original_module = fn_globals["flash_attn_cuda"]
+    original_require = fn_globals["_require_hg_varlen_symbol"]
+    called_symbols = []
+
+    def require_hg_symbol(name):
+        called_symbols.append(name)
+        return original_require(name)
+
+    fn_globals["flash_attn_cuda"] = _NoUnifiedFallback(original_module)
+    fn_globals["_require_hg_varlen_symbol"] = require_hg_symbol
+    try:
+        result = varlen_fwd_unified(*args, **kwargs)
+    finally:
+        fn_globals["flash_attn_cuda"] = original_module
+        fn_globals["_require_hg_varlen_symbol"] = original_require
+
+    assert expected_symbol in called_symbols, (
+        f"expected {expected_symbol}, got HG calls {called_symbols}"
+    )
+    return result
+
+
 # ---------------------------------------------------------------------------
 # Accuracy tests
 # ---------------------------------------------------------------------------
 @pytest.mark.parametrize("dtype", [torch.float16, torch.bfloat16])
+@pytest.mark.parametrize("use_fp8", [False, True])
 @pytest.mark.parametrize("mha_type", ["gqa"])
-@pytest.mark.parametrize("causal", [True])
+@pytest.mark.parametrize("causal", [True, False])
 @pytest.mark.parametrize("softcap", [0.0])
-@pytest.mark.parametrize("window_size", [(-1, -1)])
-@pytest.mark.parametrize("use_alibi_sqrt", [True, False])
-@pytest.mark.parametrize("use_qq_bias", [True, False])  # seqlen_q > seqlen_k 时 skip
-@pytest.mark.parametrize("use_sinks", [True, False])
-@pytest.mark.parametrize("use_mm_prefix", [True, False])
-@pytest.mark.parametrize("d", [128, 256])
+@pytest.mark.parametrize("window_size", [(-1, -1), (511, 0)])
+@pytest.mark.parametrize("use_alibi_sqrt", [False])
+@pytest.mark.parametrize("use_qq_bias", [False])  # seqlen_q > seqlen_k 时 skip
+@pytest.mark.parametrize("use_sinks", [False])
+@pytest.mark.parametrize("use_mm_prefix", [False])
+@pytest.mark.parametrize("d", [128])
 @pytest.mark.parametrize(
     "batch_size,seqlen_q,seqlen_k,block_size",
     [
         # --- 场景 1: 标准 Prefill (全量预填充) ---
         # 验证对角线处理、Is_causal 逻辑以及全量 Bias 覆盖
-        (1, 512, 512, 128),     # 单 Batch 小尺寸，快速验证
-        (4, 2048, 2048, 128),  # 匹配你日志的大尺寸，验证多 Batch 偏移
-        (2, 1024, 1024, 128),   # 较小的 block_size，增加循环迭代次数
+        # (1, 512, 512, 128),     # 单 Batch 小尺寸，快速验证
+        # (4, 2048, 2048, 128),  # 匹配你日志的大尺寸，验证多 Batch 偏移
+        # (2, 1024, 1024, 128),   # 较小的 block_size，增加循环迭代次数
 
         # --- 场景 2: Decode 场景 (增量推理) ---
         # 验证 seqlen_q=1 时，如何正确从 KV Cache 的最后位置读取信息
         # 此时 qq_bias 实际上只退化为向量加法，最容易测出指针偏移错误
-        (8, 1, 2048, 128),      # 高 Batch 的标准 Decode
-        (1, 1, 4096, 128),     # 超长上下文 Decode，验证大索引寻址
-
-        # --- 场景 3: Chunked Prefill / Speculative Decoding (分段/投机采样) ---
-        # Q 小于 K，但大于 1。这是最难写的逻辑，验证 Is_causal 的动态截断
-        (2, 128, 1024, 128),    # Q 是一小段，K 是长历史
-        (4, 256, 512, 128),     # 验证 Q 和 K 比例较近时的处理
-
-        # --- 场景 4: 边界非对称尺寸 (非 2 的幂次) ---
-        # 专门用来抓那些“假设数据一定是 BlockSize 整数倍”的 Bug
-        (1, 127, 127, 128),     # 刚好差 1 个填满 Block
-        (2, 33, 1025, 128),     # 非常细碎的 Block 和不规则长度
+        (32, 4, 2048, 128),
+        (16, 4, 2048, 128),
+        (8, 4, 2048, 128),      # 高 Batch 的标准 Decode
+        (4, 4, 2048, 128),
+        (2, 4, 2048, 128),
+        (1, 4, 4096, 128),     # 超长上下文 Decode，验证大索引寻址
+
+        # --- 场景 3: Prefix Prefill ---
+        (1, 16, 128, 128),     # fp8 prefill lower boundary
+        (1, 32, 512, 128),
+        (2, 32, 513, 128),     # non block-aligned KV length
+        (2, 64, 2048, 128),
+        (3, 96, 1537, 128),    # non power-of-two batch/length
+        (2, 128, 1024, 128),
+
+        # # --- 场景 4: 边界非对称尺寸 (非 2 的幂次) ---
+        # # 专门用来抓那些“假设数据一定是 BlockSize 整数倍”的 Bug
+        # (1, 127, 127, 128),     # 刚好差 1 个填满 Block
+        # (2, 33, 1025, 128),     # 非常细碎的 Block 和不规则长度
     ],
 )
 def test_unified_attn_2d(
     batch_size, seqlen_q, seqlen_k, block_size,
     d, causal, window_size, softcap,
     mha_type, dtype,
-    use_alibi_sqrt, use_qq_bias, use_sinks, use_mm_prefix,
+    use_alibi_sqrt, use_qq_bias, use_sinks, use_mm_prefix, use_fp8,
 ):
     device = torch.device("cuda")
     torch.manual_seed(42)
 
-    nheads = 8
-    nheads_k = 1 if mha_type == "gqa" else nheads
+    nheads = 24
+    nheads_k = 2 if mha_type == "gqa" else nheads
     softmax_scale = d ** (-0.5)
     MAX_MM_RANGES = 2
 
@@ -1310,6 +1374,8 @@ def test_unified_attn_2d(
 
     if use_mm_prefix and seqlen_q > seqlen_k:
         pytest.skip("mm_prefix not supported when seqlen_q > seqlen_k")
+    if causal and window_size != (-1, -1):
+        pytest.skip("HG local window path is selected with causal=False")
 
     # if use_mm_prefix and not causal:
     #     pytest.skip("mm_prefix_range is only meaningful with causal=True")
@@ -1320,13 +1386,28 @@ def test_unified_attn_2d(
         k_list.append(torch.randn(seqlen_k, nheads_k, d, device=device, dtype=dtype))
         v_list.append(torch.randn(seqlen_k, nheads_k, d, device=device, dtype=dtype))
 
-    q_varlen = torch.cat(q_list, dim=0)
+    if use_fp8:
+        fp8_dtype = current_platform.fp8_dtype()
+        q_kernel_list = [q.to(fp8_dtype) for q in q_list]
+        k_kernel_list = [k.to(fp8_dtype) for k in k_list]
+        v_kernel_list = [v.to(fp8_dtype) for v in v_list]
+        q_ref_list = [q.to(dtype) for q in q_kernel_list]
+        k_ref_list = [k.to(dtype) for k in k_kernel_list]
+        v_ref_list = [v.to(dtype) for v in v_kernel_list]
+    else:
+        q_kernel_list, k_kernel_list, v_kernel_list = q_list, k_list, v_list
+        q_ref_list, k_ref_list, v_ref_list = q_list, k_list, v_list
+
+    q_varlen = torch.cat(q_kernel_list, dim=0)
     cu_seqlens_q = torch.zeros(batch_size + 1, device=device, dtype=torch.int32)
     cu_seqlens_q[1:] = torch.cumsum(
         torch.tensor([seqlen_q] * batch_size, dtype=torch.int32), dim=0
     )
     seqused_k = torch.tensor([seqlen_k] * batch_size, device=device, dtype=torch.int32)
-    k_cache, v_cache, block_table = make_paged_kv(k_list, v_list, block_size, device, dtype)
+    k_cache, v_cache, block_table = make_paged_kv(k_kernel_list, v_kernel_list, block_size, device, q_varlen.dtype)
+    q_descale = torch.ones((batch_size, nheads), device=device, dtype=torch.float32) if use_fp8 else None
+    k_descale = torch.ones((batch_size, nheads_k), device=device, dtype=torch.float32) if use_fp8 else None
+    v_descale = torch.ones((batch_size, nheads_k), device=device, dtype=torch.float32) if use_fp8 else None
 
     # Build optional tensors
     alibi_slopes = None
@@ -1354,7 +1435,7 @@ def test_unified_attn_2d(
     for i in range(batch_size):
         ref_outs.append(
             ref_attn(
-                q_list[i], k_list[i], v_list[i],
+                q_ref_list[i], k_ref_list[i], v_ref_list[i],
                 causal=causal,
                 window_size=window_size,
                 softmax_scale=softmax_scale,
@@ -1369,7 +1450,20 @@ def test_unified_attn_2d(
     ref_out = torch.cat(ref_outs, dim=0)
     
     # ---- CUDA kernel ----
-    cuda_out, cuda_lse = varlen_fwd_unified(
+    expected_hg_symbol = None
+    if use_fp8 and seqlen_q >= 16:
+        expected_hg_symbol = "hg_prefix_prefill_varlen_fwd"
+    elif use_fp8 or seqlen_q == 1 or 1 < seqlen_q < 16:
+        expected_hg_symbol = "hg_prefix_decode_varlen_fwd"
+    elif seqlen_q > 16:
+        expected_hg_symbol = "hg_prefix_prefill_varlen_fwd"
+
+    varlen_runner = (
+        varlen_fwd_unified
+        if expected_hg_symbol is None
+        else lambda *args, **kwargs: varlen_fwd_unified_expect_hg(expected_hg_symbol, *args, **kwargs)
+    )
+    cuda_out, cuda_lse = varlen_runner(
         q_varlen, k_cache, v_cache,
         cu_seqlens_q, seqused_k, block_table,
         max_seqlen_q=seqlen_q,
@@ -1384,6 +1478,9 @@ def test_unified_attn_2d(
         s_aux=sinks,
         mm_prefix_range=mm_prefix_range,
         return_softmax_lse=True,
+        q_descale=q_descale,
+        k_descale=k_descale,
+        v_descale=v_descale,
     )
 
     # # ---- Triton kernel ----
@@ -1416,7 +1513,7 @@ def test_unified_attn_2d(
     # triton_max_diff = (triton_out - ref_out).abs().max().item()
 
     print(
-        f"\n[{dtype} | causal={causal} | {mha_type} | bs={batch_size} "
+        f"\n[{dtype} | fp8={use_fp8} | causal={causal} | {mha_type} | bs={batch_size} "
         f"sq={seqlen_q} sk={seqlen_k} blk={block_size} | "
         f"alibi_sqrt={use_alibi_sqrt} qq_bias={use_qq_bias} "
         f"sinks={use_sinks} mm_prefix={use_mm_prefix}]"
@@ -1424,7 +1521,7 @@ def test_unified_attn_2d(
         # f"\n  Triton max_diff={triton_max_diff:.4e}"
     )
 
-    cal_diff(cuda_out, ref_out, "out")
+    cal_diff(cuda_out, ref_out, "out", use_fp8=use_fp8)
 
 
 # ---------------------------------------------------------------------------
@@ -1440,8 +1537,8 @@ def benchmark_unified_attention():
     torch.manual_seed(42)
 
     dtype = torch.float16
-    d = 256
-    block_size = 320
+    d = 128
+    block_size = 128
 
     warmup = 10
     repeat = 50
@@ -1452,30 +1549,35 @@ def benchmark_unified_attention():
     MAX_MM_RANGES = 2
 
     # GQA
-    nheads = 8
-    nheads_k = 1
+    nheads = 24
+    nheads_k = 2
 
     # workload shapes
     shapes = [
         # (8, 2048, 2048),
         # (4, 2048, 2048),
-        (4, 1, 2048),
+        (1, 4, 51200),
+        (2, 4, 51200),
+        (4, 4, 51200),
+        (8, 4, 51200),
+        (16, 4, 51200),
+        (32, 4, 51200),
         # (4, 2048, 4096),
     ]
 
     # feature configs (C A Q S P)
     feature_configs = [
         (1,0,0,0,0),
-        (1,1,0,0,0),
-        (1,0,1,0,0),
-        (1,0,0,1,0),
-        (1,0,0,0,1),
-        (1,1,1,0,0),
-        (1,1,0,1,0),
-        (1,1,0,0,1),
-        (1,1,1,1,0),
-        (1,1,1,0,1),
-        (1,1,1,1,1),
+        # (1,1,0,0,0),
+        # (1,0,1,0,0),
+        # (1,0,0,1,0),
+        # (1,0,0,0,1),
+        # (1,1,1,0,0),
+        # (1,1,0,1,0),
+        # (1,1,0,0,1),
+        # (1,1,1,1,0),
+        # (1,1,1,0,1),
+        # (1,1,1,1,1),
     ]
 
     print("\nUnified Attention GQA Benchmark")
@@ -1485,7 +1587,8 @@ def benchmark_unified_attention():
         f"{'BS':>3} {'SQ':>6} {'SK':>6} | "
         f"{'C':>1} {'A':>1} {'Q':>1} {'S':>1} {'P':>1} | "
         f"{'CUDA(ms)':>10} {'Triton(ms)':>11} | "
-        f"{'CUDA TFLOPS':>11} {'Triton TFLOPS':>13} | {'Speedup':>8}"
+        f"{'CUDA TFLOPS':>11} {'Triton TFLOPS':>13} | "
+        f"{'CUDA(GB/s)':>10} {'Triton(GB/s)':>12} | {'Speedup':>8}"
     )
 
     print("-" * 120)
@@ -1548,6 +1651,13 @@ def benchmark_unified_attention():
 
         triton_out = torch.zeros_like(q_varlen)
 
+        total_bytes = estimate_unified_attention_bytes(
+            batch_size, seqlen_q, seqlen_k, nheads, nheads_k, d, block_size,
+            q_bytes=torch.finfo(dtype).bits // 8,
+            k_bytes=torch.finfo(dtype).bits // 8,
+            v_bytes=torch.finfo(dtype).bits // 8,
+        )
+
         for C, A, Q, S, P in feature_configs:
 
             causal = bool(C)
@@ -1655,6 +1765,9 @@ def benchmark_unified_attention():
             # FLOPs
             flops = 4.0 * batch_size * nheads * seqlen_q * seqlen_k * d
 
+            cuda_bandwidth = total_bytes / 1e9 / cuda_ms * 1000
+            triton_bandwidth = total_bytes / 1e9 / triton_ms * 1000
+
             cuda_tflops = flops / cuda_ms / 1e9
             triton_tflops = flops / triton_ms / 1e9
 
@@ -1663,11 +1776,130 @@ def benchmark_unified_attention():
                 f"{C} {A} {Q} {S} {P} | "
                 f"{cuda_ms:10.3f} {triton_ms:11.3f} | "
                 f"{cuda_tflops:11.2f} {triton_tflops:13.2f} | "
+                f"{cuda_bandwidth:10.2f} {triton_bandwidth:12.2f} | "
                 f"{triton_ms/cuda_ms:8.2f}x"
             )
 
     print("=" * 120)
 
 
+def benchmark_hg_b16_fp8_pa():
+    device = torch.device("cuda")
+    torch.manual_seed(42)
+
+    dtype = torch.bfloat16
+    fp8_dtype = current_platform.fp8_dtype()
+    d = 128
+    block_size = 128
+    warmup = 10
+    repeat = 50
+    nheads = 24
+    nheads_k = 2
+    softcap = 0.0
+    shapes = [
+        (bs, seqlen_q, 51200)
+        for seqlen_q in (1, 4)
+        for bs in (1, 2, 4, 8, 16, 32)
+    ]
+    shapes += [
+        (bs, seqlen_q, 4096)
+        for seqlen_q in (32, 128)
+        for bs in (1, 2, 4)
+    ]
+    windows = [(-1, -1), (511, 0)]
+
+    def time_fn(fn):
+        for _ in range(warmup):
+            fn()
+        torch.cuda.synchronize()
+        start = time.perf_counter()
+        for _ in range(repeat):
+            fn()
+        torch.cuda.synchronize()
+        return (time.perf_counter() - start) / repeat * 1000
+
+    print("\nHG Unified PA BF16/FP8 Benchmark")
+    print("=" * 104)
+    print(
+        f"{'BS':>3} {'SQ':>3} {'SK':>6} {'WINDOW':>12} | "
+        f"{'BF16(ms)':>9} {'FP8(ms)':>9} {'Speedup':>8} | "
+        f"{'BF16 GB/s':>10} {'FP8 GB/s':>9}"
+    )
+    print("-" * 104)
+
+    for window_size in windows:
+        for batch_size, seqlen_q, seqlen_k in shapes:
+            if seqlen_q >= 16 and window_size != (-1, -1):
+                continue
+            softmax_scale = d ** (-0.5)
+            q_list = [torch.randn(seqlen_q, nheads, d, device=device, dtype=dtype) for _ in range(batch_size)]
+            k_list = [torch.randn(seqlen_k, nheads_k, d, device=device, dtype=dtype) for _ in range(batch_size)]
+            v_list = [torch.randn(seqlen_k, nheads_k, d, device=device, dtype=dtype) for _ in range(batch_size)]
+
+            q_b16 = torch.cat(q_list, dim=0)
+            k_b16, v_b16, block_table = make_paged_kv(k_list, v_list, block_size, device, dtype)
+            q_fp8 = q_b16.to(fp8_dtype)
+            k_fp8 = k_b16.to(fp8_dtype)
+            v_fp8 = v_b16.to(fp8_dtype)
+
+            cu_seqlens_q = torch.zeros(batch_size + 1, device=device, dtype=torch.int32)
+            cu_seqlens_q[1:] = torch.cumsum(
+                torch.tensor([seqlen_q] * batch_size, dtype=torch.int32), dim=0
+            )
+            seqused_k = torch.tensor([seqlen_k] * batch_size, device=device, dtype=torch.int32)
+            q_descale = torch.ones((batch_size, nheads), device=device, dtype=torch.float32)
+            k_descale = torch.ones((batch_size, nheads_k), device=device, dtype=torch.float32)
+            v_descale = torch.ones((batch_size, nheads_k), device=device, dtype=torch.float32)
+
+            def run_b16():
+                varlen_fwd_unified(
+                    q_b16, k_b16, v_b16, cu_seqlens_q, seqused_k, block_table,
+                    max_seqlen_q=seqlen_q, max_seqlen_k=seqlen_k,
+                    softmax_scale=softmax_scale, causal=True,
+                    window_size=window_size, softcap=softcap,
+                    return_softmax_lse=False,
+                )
+
+            def run_fp8():
+                varlen_fwd_unified(
+                    q_fp8, k_fp8, v_fp8, cu_seqlens_q, seqused_k, block_table,
+                    max_seqlen_q=seqlen_q, max_seqlen_k=seqlen_k,
+                    softmax_scale=softmax_scale, causal=True,
+                    window_size=window_size, softcap=softcap,
+                    return_softmax_lse=False,
+                    q_descale=q_descale, k_descale=k_descale, v_descale=v_descale,
+                )
+
+            run_b16()
+            run_fp8()
+            torch.cuda.synchronize()
+            b16_ms = time_fn(run_b16)
+            fp8_ms = time_fn(run_fp8)
+
+            b16_bytes = estimate_unified_attention_bytes(
+                batch_size, seqlen_q, seqlen_k, nheads, nheads_k, d, block_size,
+                q_bytes=2, k_bytes=2, v_bytes=2, out_bytes=2,
+            )
+            fp8_bytes = estimate_unified_attention_bytes(
+                batch_size, seqlen_q, seqlen_k, nheads, nheads_k, d, block_size,
+                q_bytes=1, k_bytes=1, v_bytes=1, out_bytes=2,
+            )
+            print(
+                f"{batch_size:3d} {seqlen_q:3d} {seqlen_k:6d} {str(window_size):>12} | "
+                f"{b16_ms:9.3f} {fp8_ms:9.3f} {b16_ms / fp8_ms:8.2f} | "
+                f"{b16_bytes / 1e9 / b16_ms * 1000:10.2f} {fp8_bytes / 1e9 / fp8_ms * 1000:9.2f}"
+            )
+
+    print("=" * 104)
+
+
 if __name__ == "__main__":
-    benchmark_unified_attention()
+    if os.getenv("RUN_UNIFIED_BENCHMARK") == "1":
\ No newline at end of file
+        benchmark_hg_b16_fp8_pa()
+    else:
+        test_unified_attn_2d(
+            batch_size=1, seqlen_q=1, seqlen_k=40960, block_size=128,
+            d=128, causal=False, window_size=(511, 0), softcap=0.0,
+            mha_type="gqa", dtype=torch.bfloat16,
+            use_alibi_sqrt=False, use_qq_bias=False, use_sinks=False, use_mm_prefix=False,
+            use_fp8=True)