[Bugfix][ROCm]Fix Qwen3-Next-80B-A3B-Thinking inference and optimize...

[Bugfix][ROCm]Fix Qwen3-Next-80B-A3B-Thinking inference and optimize non-standard block size (544) support under rocm_atten (#31380)
Signed-off-by: vllmellm <vllm.ellm@embeddedllm.com>

tests/kernels/attention/test_prefix_prefill.py

@@ -112,6 +112,7 @@ def test_contexted_kv_attention(
     kv_cache_dtype: str,
     device: str,
     op: Callable,
+    block_size: int = 32,
 ) -> None:
     if "fp8" in kv_cache_dtype and not current_platform.has_device_capability(89):
         pytest.skip(
@@ -138,7 +139,6 @@ def test_contexted_kv_attention(
     MAX_CTX_LEN = 1024
     BS = 10
     cache_size = 640
-    block_size = 32
     max_block_per_request = 64
     query_lens = [random.randint(16, MAX_SEQ_LEN) for _ in range(BS)]
     # ensure one sequence in batch is a decode
@@ -333,6 +333,7 @@ def test_contexted_kv_attention_alibi(
     kv_cache_dtype: str,
     device: str,
     op: Callable,
+    block_size: int = 32,
 ) -> None:
     if "fp8" in kv_cache_dtype and not current_platform.has_device_capability(89):
         pytest.skip(
@@ -385,7 +386,6 @@ def test_contexted_kv_attention_alibi(
     MAX_CTX_LEN = 1024
     BS = 10
     cache_size = 640
-    block_size = 32
     max_block_per_request = 64
     query_lens = [random.randint(16, MAX_SEQ_LEN) for _ in range(BS)]
     ctx_lens = [random.randint(16, MAX_CTX_LEN) for _ in range(BS)]
@@ -637,3 +637,34 @@ def test_contexted_kv_attention_alibi_f32(
     test_contexted_kv_attention_alibi(
         num_heads, num_queries_per_kv, head_size, dtype, kv_cache_dtype, device, op
     )
+
+
+@pytest.mark.parametrize("head_size", [128])
+@pytest.mark.parametrize("dtype", DTYPES)
+@pytest.mark.parametrize("device", CUDA_DEVICES)
+@pytest.mark.parametrize("op", OPS)
+@torch.inference_mode()
+def test_qwen3_nonstandard_block_size(
+    head_size: int,
+    dtype: torch.dtype,
+    device: str,
+    op: Callable,
+) -> None:
+    """
+    A separate test function specifically added
+    for Qwen3-Next-80B (Block Size 544).
+    """
+    if not current_platform.is_rocm():
+        pytest.skip("544 block size optimization is only for ROCm.")
+
+    test_contexted_kv_attention(
+        num_heads=64,
+        num_queries_per_kv=1,
+        head_size=head_size,
+        block_size=544,
+        sliding_window=0,
+        dtype=dtype,
+        kv_cache_dtype="auto",
+        device=device,
+        op=op,
+    )

vllm/attention/ops/chunked_prefill_paged_decode.py

@@ -46,6 +46,7 @@ def kernel_paged_attention_2d(
     output_stride_0: tl.int64,  # int
     output_stride_1: tl.int64,  # int, should be equal to head_size
     BLOCK_SIZE: tl.constexpr,  # int
+    PHYSICAL_BLOCK_SIZE: tl.constexpr,  # int
     HEAD_SIZE: tl.constexpr,  # int
     HEAD_SIZE_PADDED: tl.constexpr,  # int, must be power of 2
     USE_ALIBI_SLOPES: tl.constexpr,  # bool
@@ -104,14 +105,15 @@ def kernel_paged_attention_2d(
 
     if not USE_SINKS:
         M = tl.full([num_queries_per_kv_padded], float("-inf"), dtype=tl.float32)
+        L = tl.zeros([num_queries_per_kv_padded], dtype=tl.float32)
     else:
         M = tl.load(
             sink_ptr + query_head_idx,
             mask=head_mask,
             other=float("-inf"),
         ).to(dtype=tl.float32)
+        L = tl.where(float("-inf") < M, 1.0, 0.0)
 
-    L = tl.full([num_queries_per_kv_padded], 1.0, dtype=tl.float32)
     acc = tl.zeros([num_queries_per_kv_padded, HEAD_SIZE_PADDED], dtype=tl.float32)
 
     # sequence len for this particular sequence
@@ -125,30 +127,45 @@ def kernel_paged_attention_2d(
 
     num_blocks = cdiv_fn(seq_len, BLOCK_SIZE)
 
+    offs_n = tl.arange(0, BLOCK_SIZE)
+    offs_d = tl.arange(0, HEAD_SIZE_PADDED)
     # iterate through tiles
     for j in range(0, num_blocks):
-        physical_block_idx = tl.load(block_tables_ptr + block_table_offset + j)
-
-        offs_n = tl.arange(0, BLOCK_SIZE)
-        offs_d = tl.arange(0, HEAD_SIZE_PADDED)
-
-        v_offset = (
-            physical_block_idx * stride_v_cache_0
-            + kv_head_idx * stride_v_cache_1
-            + offs_d[None, :] * stride_v_cache_2
-            + offs_n[:, None] * stride_v_cache_3
-        )
-
+        start_n = j * BLOCK_SIZE
+        # Calculate the logical location within a non-standard physical block,
+        # such as 544 in Qwen/Qwen3-Next-80B-A3B-Thinking.
+        # Supports non-contiguous mapping
+        # from logical blocks to physical blocks
+        abs_token_idx = start_n + offs_n
+        l_block_idx = abs_token_idx // PHYSICAL_BLOCK_SIZE
+        # Vectorized loading of physical block IDs
+        p_block_idx = tl.load(block_tables_ptr + block_table_offset + l_block_idx)
+        internal_offsets = abs_token_idx % PHYSICAL_BLOCK_SIZE
+
+        # 5D addressing logic of K
         k_offset = (
-            physical_block_idx * stride_k_cache_0
+            p_block_idx[None, :] * stride_k_cache_0
             + kv_head_idx * stride_k_cache_1
             + (offs_d[:, None] // x) * stride_k_cache_2
-            + offs_n[None, :] * stride_k_cache_3
+            + internal_offsets[None, :] * stride_k_cache_3
             + (offs_d[:, None] % x) * stride_k_cache_4
         )
 
+        # 4D addressing logic of V (Slot is innermost)
+        v_offset = (
+            p_block_idx[:, None] * stride_v_cache_0
+            + kv_head_idx * stride_v_cache_1
+            + offs_d[None, :] * stride_v_cache_2
+            + internal_offsets[:, None] * stride_v_cache_3
+        )
+
         # K : (HEAD_SIZE, BLOCK_SIZE)
-        K_load = tl.load(key_cache_ptr + k_offset, mask=dim_mask[:, None], other=0.0)
+        K_load = tl.load(
+            key_cache_ptr + k_offset,
+            mask=dim_mask[:, None],
+            other=0.0,
+            eviction_policy="evict_last",
+        )
 
         if K_load.dtype.is_fp8():
             K = (K_load.to(tl.float32) * tl.load(k_scale)).to(Q.dtype)
@@ -156,7 +173,12 @@ def kernel_paged_attention_2d(
             K = K_load
 
         # V : (BLOCK_SIZE, HEAD_SIZE)
-        V_load = tl.load(value_cache_ptr + v_offset, mask=dim_mask[None, :], other=0.0)
+        V_load = tl.load(
+            value_cache_ptr + v_offset,
+            mask=dim_mask[None, :],
+            other=0.0,
+            eviction_policy="evict_last",
+        )
 
         if V_load.dtype.is_fp8():
             V = (V_load.to(tl.float32) * tl.load(v_scale)).to(Q.dtype)
@@ -167,9 +189,9 @@ def kernel_paged_attention_2d(
         boundary = tl.full([BLOCK_SIZE], seq_len, dtype=tl.int32)
         seq_mask = seq_offset[None, :] < boundary
 
-        # S : (num_queries_per_kv, BLOCK_SIZE,)
-        S = tl.where(head_mask[:, None] & seq_mask, 0.0, float("-inf")).to(tl.float32)
-        S += scale * tl.dot(Q, K)
+        # First calculate the dot, then apply the mask.
+        qk = scale * tl.dot(Q, K)
+        S = tl.where(head_mask[:, None] & seq_mask, qk, float("-inf"))
 
         context_len = seq_len - 1
 
@@ -184,13 +206,15 @@ def kernel_paged_attention_2d(
         m_j = tl.maximum(M, tl.max(S, axis=1))
 
         # P : (num_queries_per_kv, BLOCK_SIZE,)
-        P = tl.exp(S - m_j[:, None])
+        p = tl.exp(S - m_j[:, None])
+        p = tl.where(m_j[:, None] == float("-inf"), 0.0, p)
 
         # l_j : (num_queries_per_kv,)
-        l_j = tl.sum(P, axis=1)
+        l_j = tl.sum(p, axis=1)
 
         # alpha : (num_queries_per_kv, )
         alpha = tl.exp(M - m_j)
+        alpha = tl.where(float("-inf") == M, 0.0, alpha)
 
         # acc : (num_queries_per_kv, BLOCK_SIZE,)
         acc = acc * alpha[:, None]
@@ -200,10 +224,10 @@ def kernel_paged_attention_2d(
         M = m_j
 
         # acc : (num_queries_per_kv, BLOCK_SIZE,)
-        acc += tl.dot(P.to(V.dtype), V)
+        acc += tl.dot(p.to(V.dtype), V)
 
     # epilogue
-    acc = acc / L[:, None]
+    acc = acc / (L[:, None] + 1e-10)
     if USE_FP8:
         acc = acc * tl.load(out_scale_inv)
         acc = tl.clamp(acc, FP8_MIN, FP8_MAX)
@@ -241,9 +265,10 @@ def chunked_prefill_paged_decode(
     output_scale=None,
     # Optional tensor for sinks
     sinks=None,
+    is_block_table_ptr: bool = False,
 ):
     if sm_scale is None:
-        sm_scale = 1.0 / (query.shape[1] ** 0.5)
+        sm_scale = 1.0 / (query.shape[2] ** 0.5)
 
     use_alibi_slopes = alibi_slopes is not None
 
@@ -315,6 +340,16 @@ def chunked_prefill_paged_decode(
         alibi_slopes,
         sinks,
     )
+    # Triton is only forced when encountering a non-standard block
+    # like Qwen3 with a size of 544.
+    # 1. Check if block_size is a power of 2 (16, 32, 64...)
+    # 2. If it's a power of 2, we trust the vLLM's native use_custom decision.
+    # 3. If it's not a power of 2 (such as Qwen3's 544),
+    # then our Triton path is forced.
+    is_pow2 = block_size > 0 and (block_size & (block_size - 1) == 0)
+    if not is_pow2:
+        use_custom = False
+
     if use_custom:
         _PARTITION_SIZE_ROCM = 256
         max_num_partitions = (
@@ -356,6 +391,25 @@ def chunked_prefill_paged_decode(
             fp8_out_scale=output_scale,
         )
     else:
+        real_block_size = value_cache.shape[3]
+        # The standard model directly uses the original block_size.
+        # Non-standard 544 uses 32 to accommodate integer division logic.
+        TRITON_BLOCK_SIZE = block_size if is_pow2 else 32
+        if is_block_table_ptr:
+            # Using the physical base address of tensors
+            kv_element_size = key_cache.element_size()
+            block_byte_stride = key_cache.stride(0) * kv_element_size
+            # Get the starting physical address of the KV Cache
+            base_addr = key_cache.data_ptr()
+
+            # Normalization: Directly calculate the block offset
+            # of the pointer relative to the base address
+            processed_block_table = ((block_table - base_addr) // block_byte_stride).to(
+                torch.int32
+            )
+        else:
+            processed_block_table = block_table.to(torch.int32)
+
         kernel_paged_attention_2d[
             (
                 num_seqs,
@@ -367,7 +421,7 @@ def chunked_prefill_paged_decode(
             key_cache_ptr=key_cache,
             value_cache_ptr=value_cache,
             sink_ptr=sinks,
-            block_tables_ptr=block_table,
+            block_tables_ptr=processed_block_table,
             seq_lens_ptr=seq_lens,
             alibi_slopes_ptr=alibi_slopes,
             scale=sm_scale,
@@ -377,12 +431,13 @@ def chunked_prefill_paged_decode(
             num_query_heads=num_query_heads,
             num_queries_per_kv=num_queries_per_kv,
             num_queries_per_kv_padded=num_queries_per_kv_padded,
-            block_table_stride=block_table.stride(0),
+            block_table_stride=processed_block_table.stride(0),
             query_stride_0=query.stride(0),
             query_stride_1=query.stride(1),
             output_stride_0=output.stride(0),
             output_stride_1=output.stride(1),
-            BLOCK_SIZE=block_size,
+            BLOCK_SIZE=TRITON_BLOCK_SIZE,
+            PHYSICAL_BLOCK_SIZE=real_block_size,
             HEAD_SIZE=head_size,
             HEAD_SIZE_PADDED=triton.next_power_of_2(head_size),
             USE_ALIBI_SLOPES=use_alibi_slopes,

vllm/attention/ops/prefix_prefill.py

@@ -79,6 +79,7 @@ def _fwd_kernel(
     BLOCK_DMODEL: tl.constexpr,
     BLOCK_DMODEL_PADDED: tl.constexpr,
     BLOCK_SIZE: tl.constexpr,
+    PHYSICAL_BLOCK_SIZE: tl.constexpr,
     BLOCK_N: tl.constexpr,
     SLIDING_WINDOW: tl.constexpr,
     num_unroll_cache: tl.constexpr,
@@ -139,42 +140,52 @@ def _fwd_kernel(
     # initialize pointer to m and l
     if not USE_SINKS:
         m_i = tl.full([BLOCK_M], float("-inf"), dtype=tl.float32)
+        l_i = tl.zeros([BLOCK_M], dtype=tl.float32)
     else:
         m_i = tl.load(
             sink_ptr + tl.full([BLOCK_M], cur_head, dtype=tl.int64),
             mask=(offs_m < cur_batch_query_len),
             other=float("-inf"),
         ).to(dtype=tl.float32)
+        l_i = tl.where(m_i > float("-inf"), 1.0, 0.0)
 
-    l_i = tl.full([BLOCK_M], 1.0, dtype=tl.float32)
     acc = tl.zeros([BLOCK_M, BLOCK_DMODEL_PADDED], dtype=tl.float32)  # [M,D]
 
     # compute query against context (no causal mask here)
     for start_n in tl.range(
         0, cur_batch_ctx_len, BLOCK_SIZE, loop_unroll_factor=num_unroll_cache
     ):
-        start_n = tl.multiple_of(start_n, BLOCK_SIZE)
-        # -- compute qk ----
+        # Under a block size of 544 (Qwen/Qwen3-Next-80B-A3B-Thinking),
+        # replace one physical block every 17 32-Tile blocks
+        # Calculate the logical block index of each of the 32 tokens
+        # in the current Tile (handling cross-block cases).
+        token_indices = start_n + offs_bs_n
+        bn_logical_indices = token_indices // PHYSICAL_BLOCK_SIZE
+
+        # 2. Vectorized loading of physical block IDs from B_Loc
         bn = tl.load(
-            B_Loc
-            + cur_batch * stride_b_loc_b
-            + (start_n // BLOCK_SIZE) * stride_b_loc_s
+            B_Loc + cur_batch * stride_b_loc_b + bn_logical_indices * stride_b_loc_s
         ).to(tl.int64)
-        # [D,BLOCK_SIZE]
+
+        # 3. Calculate the exact offset of
+        # each token within its physical block.
+        internal_offsets = token_indices % PHYSICAL_BLOCK_SIZE
+
+        # Addressing of K (5D)
         off_k = (
             bn[None, :] * stride_k_cache_bs
             + cur_kv_head * stride_k_cache_h
             + (offs_d[:, None] // x) * stride_k_cache_d
-            + ((start_n + offs_bs_n[None, :]) % BLOCK_SIZE) * stride_k_cache_bl
+            + internal_offsets[None, :] * stride_k_cache_bl
             + (offs_d[:, None] % x) * stride_k_cache_x
         )
 
-        # [BLOCK_SIZE,D]
+        # Addressing of V (4D)
         off_v = (
             bn[:, None] * stride_v_cache_bs
             + cur_kv_head * stride_v_cache_h
             + offs_d[None, :] * stride_v_cache_d
-            + offs_bs_n[:, None] * stride_v_cache_bl
+            + internal_offsets[:, None] * stride_v_cache_bl
         )
 
         if (
@@ -195,12 +206,12 @@ def _fwd_kernel(
         else:
             k = k_load
 
-        qk = tl.zeros([BLOCK_M, BLOCK_SIZE], dtype=tl.float32)  # [M,N]
-        qk = tl.dot(q, k, acc=qk, input_precision=IN_PRECISION)
+        # qk = tl.zeros([BLOCK_M, BLOCK_SIZE], dtype=tl.float32)  # [M,N]
+        qk = sm_scale * tl.dot(q, k, input_precision=IN_PRECISION)
         qk = tl.where(
             (start_n + offs_bs_n[None, :]) < cur_batch_ctx_len, qk, float("-inf")
         )
-        qk *= sm_scale
+        # qk *= sm_scale
         if SLIDING_WINDOW > 0:
             # (cur_batch_ctx_len + offs_m[:, None]) are the positions of
             # Q entries in sequence
@@ -217,14 +228,16 @@ def _fwd_kernel(
                 (cur_batch_ctx_len + offs_m[:, None]) - (start_n + offs_bs_n[None, :])
                 < SLIDING_WINDOW,
                 qk,
-                -10000,
+                float("-inf"),
             )
 
         # compute running maximum
         m_ij = tl.maximum(m_i, tl.max(qk, axis=1))
         p = tl.exp(qk - m_ij[:, None])
+        p = tl.where(m_ij[:, None] == float("-inf"), 0.0, p)
         l_ij = tl.sum(p, axis=1)
         alpha = tl.exp(m_i - m_ij)
+        alpha = tl.where(m_i == float("-inf"), 0.0, alpha)
         acc = acc * alpha[:, None]
 
         # update acc
@@ -293,14 +306,17 @@ def _fwd_kernel(
             qk = tl.where(
                 offs_m[:, None] - (start_n + offs_n[None, :]) < SLIDING_WINDOW,
                 qk,
-                -10000,
+                float("-inf"),
             )
 
         # compute running maximum
         m_ij = tl.maximum(m_i, tl.max(qk, axis=1))
         p = tl.exp(qk - m_ij[:, None])
+        p = tl.where(m_ij[:, None] == float("-inf"), 0.0, p)
         l_ij = tl.sum(p, axis=1)
         alpha = tl.exp(m_i - m_ij)
+        # To prevent NaN from appearing in the first round
+        alpha = tl.where(m_i == float("-inf"), 0.0, alpha)
         acc = acc * alpha[:, None]
 
         # update acc
@@ -317,7 +333,7 @@ def _fwd_kernel(
         l_i = l_i * alpha + l_ij
         m_i = m_ij
 
-    acc = acc / l_i[:, None]
+    acc = acc / (l_i[:, None] + 1e-10)
 
     # initialize pointers to output
     off_o = (
@@ -637,6 +653,7 @@ def context_attention_fwd(
     skip_decode=False,
     fp8_out_scale=None,
     sinks=None,
+    is_block_table_ptr: bool = False,
 ):
     q_dtype_is_f32 = q.dtype is torch.float32
 
@@ -689,6 +706,19 @@ def context_attention_fwd(
     if sliding_window is None or sliding_window <= 0:
         sliding_window = 0
 
+    if is_block_table_ptr:
+        kv_element_size = k_cache.element_size()
+        block_byte_stride = k_cache.stride(0) * kv_element_size
+        # The physical starting point of the obtained KV Cache Pool
+        base_addr = k_cache.data_ptr()
+
+        mask = b_loc > 0
+        processed_b_loc = torch.where(
+            mask, (b_loc - base_addr) // block_byte_stride, b_loc
+        ).to(torch.int32)
+    else:
+        processed_b_loc = b_loc.to(torch.int32)
+
     if alibi_slopes is not None:
         assert sinks is None, "Sinks arg is not supported with alibi"
         assert fp8_out_scale is None, "FP8 output not supported with alibi"
@@ -752,7 +782,24 @@ def context_attention_fwd(
     max_seq_len = 0 if max_seq_len is None else max_seq_len
     extra_kargs = {}
     if current_platform.is_rocm():
-        extra_kargs = {"kpack": 1, "waves_per_eu": 2}
+        extra_kargs = {}
+
+    real_block_size = v_cache.shape[3]
+    is_pow2 = real_block_size > 0 and (real_block_size & (real_block_size - 1) == 0)
+    # For standard models involving powers of 2,
+    # follow the original logic (Llama 128/64)
+    # For non-standard models (Qwen3-next block_size 544), set to 32.
+    if is_pow2:
+        BLOCK_M = 128
+        BLOCK_N = 64
+    else:
+        BLOCK_M = 32
+        BLOCK_N = 32
+
+    # TRITON_BLOCK_SIZE is kept at 32 to ensure
+    # correct alignment logic when the kernel handles
+    # non-standard sizes (such as 544).
+    TRITON_BLOCK_SIZE = 32
 
     grid_fn = lambda META: (batch, head, triton.cdiv(max_input_len, META["BLOCK_M"]))
     _fwd_kernel[grid_fn](
@@ -762,7 +809,7 @@ def context_attention_fwd(
         k_cache,
         v_cache,
         sinks,
-        b_loc,
+        processed_b_loc,
         sm_scale,
         k_scale,
         v_scale,
@@ -771,8 +818,8 @@ def context_attention_fwd(
         b_seq_len,
         k_cache.shape[4],
         o,
-        b_loc.stride(0),
-        b_loc.stride(1),
+        processed_b_loc.stride(0),
+        processed_b_loc.stride(1),
         q.stride(0),
         q.stride(1),
         q.stride(2),
@@ -785,16 +832,17 @@ def context_attention_fwd(
         o.stride(0),
         o.stride(1),
         o.stride(2),
-        k_cache.stride(0),
-        k_cache.stride(1),
-        k_cache.stride(2),
-        k_cache.stride(3),
-        k_cache.stride(4),  # [num_blocks, num_kv_heads, head_size/x, block_size, x]
-        v_cache.stride(0),
-        v_cache.stride(1),
-        v_cache.stride(2),
-        v_cache.stride(3),  # [num_blocks, num_kv_heads, head_size, block_size]
-        BLOCK_SIZE=v_cache.shape[3],
+        stride_k_cache_bs=k_cache.stride(0),
+        stride_k_cache_h=k_cache.stride(1),
+        stride_k_cache_d=k_cache.stride(2),
+        stride_k_cache_bl=k_cache.stride(3),
+        stride_k_cache_x=k_cache.stride(4),
+        stride_v_cache_bs=v_cache.stride(0),
+        stride_v_cache_h=v_cache.stride(1),
+        stride_v_cache_d=v_cache.stride(2),
+        stride_v_cache_bl=v_cache.stride(3),
+        BLOCK_SIZE=TRITON_BLOCK_SIZE,
+        PHYSICAL_BLOCK_SIZE=real_block_size,
         num_queries_per_kv=num_queries_per_kv,
         IN_PRECISION=IN_PRECISION,
         BLOCK_DMODEL=Lk,
@@ -802,8 +850,8 @@ def context_attention_fwd(
         SLIDING_WINDOW=sliding_window,
         SKIP_DECODE=skip_decode,
         USE_FP8=fp8_out_scale is not None,
-        BLOCK_M=128,
-        BLOCK_N=64,
+        BLOCK_M=BLOCK_M,
+        BLOCK_N=BLOCK_N,
         num_unroll_cache=4,
         num_unroll_request=1,
         num_warps=4,

vllm/attention/ops/triton_reshape_and_cache_flash.py

@@ -20,10 +20,15 @@ def reshape_and_cache_kernel_flash(
     key_stride: tl.int64,
     value_stride: tl.int64,
     block_stride: tl.int64,
+    head_stride: tl.int64,
+    dim_stride_k: tl.int64,
+    dim_stride_v: tl.int64,
     page_stride: tl.int64,
     num_heads: tl.constexpr,
     head_size: tl.constexpr,
     block_size: tl.constexpr,
+    x: tl.constexpr,
+    USE_HEAD_MAJOR_LAYOUT: tl.constexpr,
     # FP8 flags
     FP8_KV_CACHE: tl.constexpr,
     # tune parameters
@@ -35,17 +40,38 @@ def reshape_and_cache_kernel_flash(
         # Padding token that should be ignored.
         return
 
-    tile_i = tl.program_id(axis=1)
-    tile_offs = tl.arange(0, TILE_SIZE)
-    tile_pos = tile_i * TILE_SIZE + tile_offs
-
     block_idx = slot_idx // block_size
     block_offset = slot_idx % block_size
 
+    tile_i = tl.program_id(axis=1)
+    tile_offs = tl.arange(0, TILE_SIZE)
+    tile_pos = tile_i * TILE_SIZE + tile_offs
     src_key_idx = token_idx * key_stride
     src_value_idx = token_idx * value_stride
 
-    tgt_idx = block_idx * block_stride + block_offset * page_stride
+    if USE_HEAD_MAJOR_LAYOUT:
+        # Decompose the tile index back into head and dim coordinates.
+        cur_head = tile_pos // head_size
+        cur_dim = tile_pos % head_size
+        # Value addressing (4D): [Block, Head, Dim, Slot]
+        tgt_idx_v = (
+            block_idx * block_stride
+            + cur_head * head_stride
+            + cur_dim * dim_stride_v
+            + block_offset * 1
+        )
+        # Key addressing (5D): [Block, Head, Dim//8, Slot, 8]
+        tgt_idx_k = (
+            block_idx * block_stride
+            + cur_head * head_stride
+            + (cur_dim // x) * dim_stride_k
+            + block_offset * x
+            + (cur_dim % x)
+        )
+    else:
+        tgt_base = block_idx * block_stride + block_offset * page_stride
+        tgt_idx_k = tgt_base + tile_pos
+        tgt_idx_v = tgt_base + tile_pos
 
     # [TILE_SIZE]
     key_load = tl.load(
@@ -73,12 +99,12 @@ def reshape_and_cache_kernel_flash(
         value_tile = value_load
 
     tl.store(
-        key_cache_ptr + tgt_idx + tile_pos,
+        key_cache_ptr + tgt_idx_k,
         key_tile,
         mask=tile_pos < (num_heads * head_size),
     )
     tl.store(
-        value_cache_ptr + tgt_idx + tile_pos,
+        value_cache_ptr + tgt_idx_v,
         value_tile,
         mask=tile_pos < (num_heads * head_size),
     )
@@ -99,17 +125,26 @@ def triton_reshape_and_cache_flash(
 ):
     num_heads = key.shape[1]
     head_size = key.shape[2]
-    block_size = key_cache.shape[1]
-    n = num_heads * head_size
 
+    use_head_major_layout = key_cache.ndim == 5
+    if use_head_major_layout:
+        block_size = key_cache.shape[3]
+        x = key_cache.shape[4]
+        head_stride = key_cache.stride(1)
+        dim_stride_k = key_cache.stride(2)
+        dim_stride_v = value_cache.stride(2)
+    else:
+        block_size = key_cache.shape[1]
+        x = 1
+        dim_stride_k = 0
+        dim_stride_v = 0
+        head_stride = key_cache.stride()[2]
+    n = num_heads * head_size
     key_stride = key.stride()[0]
     value_stride = value.stride()[0]
     block_stride = key_cache.stride()[0]
     page_stride = key_cache.stride()[1]
 
-    head_stride = key_cache.stride()[2]
-    assert head_stride == head_size, "only continous heads are supported"
-
     assert kv_cache_dtype == "auto" or kv_cache_dtype.startswith("fp8"), (
         f"unsupported kv_cache_dtype (str), got {kv_cache_dtype}."
     )
@@ -171,10 +206,15 @@ def triton_reshape_and_cache_flash(
         key_stride=key_stride,
         value_stride=value_stride,
         block_stride=block_stride,
+        head_stride=head_stride,
+        dim_stride_k=dim_stride_k,
+        dim_stride_v=dim_stride_v,
         page_stride=page_stride,
         num_heads=num_heads,
         head_size=head_size,
         block_size=block_size,
+        x=x,
+        USE_HEAD_MAJOR_LAYOUT=use_head_major_layout,
         # FP8 flags
         FP8_KV_CACHE=FP8_KV_CACHE,
         # autotune parameters

vllm/v1/attention/backends/rocm_attn.py

@@ -15,6 +15,9 @@ from vllm.attention.backends.abstract import (
 )
 from vllm.attention.ops.chunked_prefill_paged_decode import chunked_prefill_paged_decode
 from vllm.attention.ops.paged_attn import PagedAttention
+from vllm.attention.ops.triton_reshape_and_cache_flash import (
+    triton_reshape_and_cache_flash,
+)
 from vllm.config import VllmConfig
 from vllm.logger import init_logger
 from vllm.model_executor.layers.quantization.utils.quant_utils import (
@@ -321,16 +324,38 @@ class RocmAttentionImpl(AttentionImpl):
         if self.kv_sharing_target_layer_name is None:
             # Reshape the input keys and values and store them in the cache.
             # Skip this if sharing KV cache with an earlier attention layer.
-            PagedAttention.write_to_paged_cache(
-                key,
-                value,
-                key_cache,
-                value_cache,
-                attn_metadata.slot_mapping,
-                self.kv_cache_dtype,
-                layer._k_scale,
-                layer._v_scale,
-            )
+
+            # Get the actual block_size from value_cache
+            # value_cache shape: [num_blocks, num_heads, head_size, block_size]
+            block_size = value_cache.shape[3]
+            # Determine if it is a power of 2
+            is_pow2 = block_size > 0 and (block_size & (block_size - 1) == 0)
+
+            if is_pow2:
+                # Normal 16, 32, 64, etc., use vLLM native HIP C++ logic
+                PagedAttention.write_to_paged_cache(
+                    key,
+                    value,
+                    key_cache,
+                    value_cache,
+                    attn_metadata.slot_mapping,
+                    self.kv_cache_dtype,
+                    layer._k_scale,
+                    layer._v_scale,
+                )
+            else:
+                # Case B: Non-standard blocks (e.g., 544 in Qwen3),
+                # force using our modified Triton logic
+                triton_reshape_and_cache_flash(
+                    key,
+                    value,
+                    key_cache,
+                    value_cache,
+                    attn_metadata.slot_mapping,
+                    self.kv_cache_dtype,
+                    layer._k_scale,
+                    layer._v_scale,
+                )
 
         if self.kv_cache_dtype.startswith("fp8"):
             key_cache = key_cache.view(self.fp8_dtype)