GLM-5.2-FP8 with DSA enablement

vllm_gaudi/attention/backends/hpu_attn.py

@@ -260,6 +260,10 @@ def __init__(
                                                  f"heads in the layer. Sinks shape: {sinks.shape}, "
                                                  f"num_heads: {num_heads}.")
 
+
+        self.topk_indices_buffer = kwargs.get('topk_indices_buffer')
+        self.is_sparse = self.topk_indices_buffer is not None
+
     def forward_mha(  # type: ignore
             self, q: torch.Tensor, latent_vec_k: torch.Tensor, k_cache: torch.Tensor,
             attn_metadata: HPUAttentionMetadata) -> torch.Tensor:
@@ -353,6 +357,60 @@ def forward_mqa(  # type: ignore
                                                   kv_lora_rank=self.kv_lora_rank)
         return output
 
+    @torch.compiler.disable
+    def forward_mqa_sparse(self, q, k_cache, attn_metadata, topk_indices):
+        """Sparse MLA decode: attend to only the top-K cache entries.
+
+        topk_indices uses -1 as the "no token" sentinel (matching upstream's
+        SparseAttnIndexer convention: see vllm.model_executor.layers.
+        sparse_attn_indexer). Rows/slots equal to -1 are padding: their cache
+        read is discarded and their attention score is masked out below,
+        instead of relying on seq_lens_tensor/context_lens_tensor, which are
+        always None on HPU decode for models without mamba-like layers.
+        """
+        if isinstance(k_cache, tuple):
+            k_cache = k_cache[0]
+        batch_size = q.shape[0]
+        topk = topk_indices.shape[1]
+        topk_indices = topk_indices[:batch_size]
+        pad_mask = topk_indices == -1
+
+        # Gather top-K latent KV from cache using physical slot indices.
+        # Clamp the -1 sentinel to a safe index; the gathered content for
+        # padded slots is discarded by the mask below.
+        flat_idx = topk_indices.clamp(min=0).reshape(-1)
+        selected = k_cache[flat_idx].view(batch_size, topk, -1)
+
+        # Decompress KV
+        k_c, k_pe = selected.split([self.kv_lora_rank, self.qk_rope_head_dim], dim=-1)
+        kv_nope = self.kv_b_proj(k_c.reshape(-1, self.kv_lora_rank))[0]
+        kv_nope = kv_nope.view(batch_size, topk, self.num_heads, self.qk_nope_head_dim + self.v_head_dim)
+        k_nope, v = kv_nope.split([self.qk_nope_head_dim, self.v_head_dim], dim=-1)
+        k_pe_exp = k_pe.unsqueeze(2).expand(-1, -1, self.num_heads, -1)
+        key = torch.cat([k_nope, k_pe_exp], dim=-1)
+
+        # q: [B, H, D] -> [B, H, 1, D]
+        # key: [B, T, H, D] -> [B, H, T, D]
+        key = key.permute(0, 2, 1, 3)
+        v = v.permute(0, 2, 1, 3)
+        attn = torch.matmul(q.unsqueeze(2), key.transpose(-1, -2))
+
+        # Use finite minimum value to avoid NaN from softmax(-inf / -inf)
+        # when an entire row is masked (empty/padded request).
+        attn = attn.masked_fill(pad_mask.unsqueeze(1).unsqueeze(2), torch.finfo(attn.dtype).min)
+
+        attn = torch.softmax(attn * self.scale, dim=-1)
+        # Zero output for rows where every top-k slot is the -1 sentinel.
+        # `.to(attn.dtype)` (not `.float()`): attn is bf16 here, and
+        # torch.matmul below does not type-promote against a bf16 `v`.
+        # 4D view [B, 1, 1, 1] to broadcast correctly against attn's
+        # [B, H, 1, T]; a 3D [B, 1, 1] view would silently misalign against
+        # the heads dim instead of the batch dim.
+        empty_mask = pad_mask.all(dim=-1).view(batch_size, 1, 1, 1)
+        attn = attn * (~empty_mask).to(attn.dtype)
+        out = torch.matmul(attn, v).squeeze(2)
+        return out.reshape(-1, self.num_heads * self.v_head_dim)
+
     # NOTE(Xinyu): Make the loaded weight contiguous to avoid the transpose
     # during each graph execution
     def process_weights_after_loading(self, act_dtype: torch.dtype):

vllm_gaudi/attention/oot_mla.py

@@ -165,13 +165,14 @@ def forward_impl(
         if is_prefill:
             output = self.impl.forward_mha(q, latent_vec_k, kv_cache, attn_metadata)
             return output
+        elif self.use_sparse and getattr(self.impl, 'topk_indices_buffer', None) is not None:
+            output = self.impl.forward_mqa_sparse(q, kv_cache, attn_metadata, self.impl.topk_indices_buffer)
+            return output
         else:
             output = self.impl.forward_mqa(decode_ql_nope, q_pe, kv_cache, attn_metadata)
             output = self._v_up_proj(output)
             return output
-            # NOTE(Xinyu): Make the loaded weight contiguous to avoid the transpose
 
-    # during each graph execution
     def process_weights_after_loading(self, act_dtype: torch.dtype):
         # HPU-specific: when VLLM_HPU_FORCE_CHANNEL_FP8=True (default), block-quantized
         # FP8 weights (e.g. kv_b_proj in DeepSeek-R1) are converted to channel-wise FP8.
@@ -310,10 +311,7 @@ def __init__(
         # None for DeepSeek-V2/R1 (no gate proj), leaving the HPU path unchanged.
         self.g_proj = mla_modules.g_proj
 
-        # DSA sparse attention is not implemented on HPU: sparse layers run as
-        # dense MLA and the indexer must never be invoked (its kernels and the
-        # DeepseekV32IndexerBackend are CUDA-only).
-        self.skip_topk = skip_topk or self.is_sparse
+        self.skip_topk = skip_topk
         # vllm#45964 (DCP query replication) added `self.dcp_q_replicate`, which
         # the base MultiHeadLatentAttentionWrapper.forward (inherited here, since
         # we do not override forward) reads and forwards to mla_attn. Because we
@@ -343,8 +341,8 @@ def __init__(
             quant_config=quant_config,
             prefix=layer_name,
             kv_b_proj=self.kv_b_proj,
-            # Dense-MLA fallback: never request a sparse backend on HPU.
-            use_sparse=False,
+            use_sparse=self.is_sparse,
             indexer=self.indexer,
+            topk_indices_buffer=mla_modules.topk_indices_buffer,
             non_causal_multi_token_decode=non_causal_multi_token_decode,
         )

vllm_gaudi/extension/features.py

@@ -97,7 +97,9 @@ def get_features():
         ValueFromList('prompt_attn_impl', supported_attn_impls),
         Value('skip_warmup', False),
         Value('merged_prefill', False),
-        Value('use_contiguous_pa', Disabled('prefix_caching'), env_var='VLLM_CONTIGUOUS_PA'),
+        Value('use_contiguous_pa',
+              All(Disabled('prefix_caching'), Not(ModelType('glm_moe_dsa'))),
+              env_var='VLLM_CONTIGUOUS_PA'),
         Value('use_bucketing', True, env_var='VLLM_ENABLE_BUCKETING'),
         Value('bucketing_strategy',
               'exp',

vllm_gaudi/models/deepseek_v2.py

@@ -3,6 +3,8 @@
 
 from vllm.distributed import get_pp_group
 from vllm.model_executor.models import deepseek_v2
+from vllm.model_executor.models.deepseek_v2 import (DeepseekV32IndexerCache, Indexer)
+from vllm.model_executor.layers.sparse_attn_indexer import SparseAttnIndexer
 from vllm.sequence import IntermediateTensors
 
 
@@ -87,24 +89,59 @@ def _hpu_deepseek_v2_model_forward(
 # Applies to DeepseekV2/V3/Deepseek/GlmMoe/DSA — all share model_cls = DeepseekV2Model.
 deepseek_v2.DeepseekV2Model.forward = _hpu_deepseek_v2_model_forward
 
-_orig_deepseek_v2_model_load_weights = deepseek_v2.DeepseekV2Model.load_weights
+# ---------------------------------------------------------------------------
+# DSA / Indexer enablement on HPU
+# ---------------------------------------------------------------------------
 
+# --- IndexerCache: BF16 storage instead of FP8 uint8 -----------------------
+_orig_indexer_cache_init = DeepseekV32IndexerCache.__init__
 
-def _hpu_deepseek_v2_model_load_weights(self, weights):
-    """Drop GLM-5 DSA shared-indexer projection weights (`indexers_proj`).
 
-    vLLM's DeepseekV2Model has no module for them, and on HPU DSA layers run
-    as dense MLA with the indexer never executed, so the projection that
-    shares indexer K caches across layers is dead weight here.
-    """
+def _hpu_indexer_cache_init(self, head_dim, dtype, prefix, cache_config):
+    if dtype == torch.uint8:
+        head_dim = head_dim * 128 // (128 + 4)
+        dtype = torch.bfloat16
+    _orig_indexer_cache_init(self, head_dim, dtype, prefix, cache_config)
+
+
+DeepseekV32IndexerCache.__init__ = _hpu_indexer_cache_init
+
+
+def _hpu_indexer_cache_get_attn_backend(self):
+    from vllm_gaudi.attention.backends.hpu_attn import HPUMLAAttentionBackend
+    return HPUMLAAttentionBackend
+
+
+DeepseekV32IndexerCache.get_attn_backend = _hpu_indexer_cache_get_attn_backend
+
+
+# --- Indexer.forward: BF16 path, skip FP8 quantization ---------------------
+def _hpu_indexer_forward(self, hidden_states, qr, positions, rotary_emb):
+    q, _ = self.wq_b(qr)
+    q = q.view(-1, self.n_head, self.head_dim)
+    q_pe, q_nope = torch.split(q, [self.rope_dim, self.head_dim - self.rope_dim], dim=-1)
+    kw, _ = self.wk_weights_proj(hidden_states)
+    kw = kw.reshape(-1, kw.shape[-1])
+    k, weights = torch.split(kw, [self.head_dim, self.n_head], dim=-1)
+    k = self.k_norm(k.contiguous())
+    k_pe, k_nope = torch.split(k, [self.rope_dim, self.head_dim - self.rope_dim], dim=-1)
+    q_pe, k_pe = rotary_emb(positions, q_pe, k_pe.unsqueeze(1))
+    q_pe = q_pe.reshape(-1, self.n_head, self.rope_dim)
+    k_pe = k_pe.reshape(-1, self.rope_dim)
+    k_nope = k_nope.reshape(-1, self.head_dim - self.rope_dim)
+    q = torch.cat([q_pe, q_nope], dim=-1)
+    k = torch.cat([k_pe, k_nope], dim=-1)
+    weights = weights.reshape(-1, self.n_head) * self.softmax_scale * self.n_head_scale
+    return self.indexer_op(hidden_states, q, k, weights)
+
+
+Indexer.forward = _hpu_indexer_forward
 
-    def _filtered(ws):
-        for name, weight in ws:
-            if ".indexers_proj." in name:
-                continue
-            yield name, weight
 
-    return _orig_deepseek_v2_model_load_weights(self, _filtered(weights))
+# --- SparseAttnIndexer: dispatch to HPU forward -----------------------------
+def _hpu_sparse_indexer_forward_native(self, hidden_states, q_quant, k, weights):
+    from vllm_gaudi.ops.hpu_sparse_attn_indexer import forward_hpu
+    return forward_hpu(self, hidden_states, q_quant, k, weights)
 
 
-deepseek_v2.DeepseekV2Model.load_weights = _hpu_deepseek_v2_model_load_weights
+SparseAttnIndexer.forward_native = _hpu_sparse_indexer_forward_native

vllm_gaudi/ops/hpu_sparse_attn_indexer.py

@@ -0,0 +1,88 @@
+# SPDX-License-Identifier: Apache-2.0
+
+import torch
+from vllm.forward_context import get_forward_context
+
+
+def _fill_invalid(buf, n, device):
+    """Fill topk_indices_buffer rows 0..n-1 with the upstream -1 sentinel.
+
+    -1 means "no token" (see vllm.model_executor.layers.sparse_attn_indexer),
+    consumed by forward_mqa_sparse to mask out padding instead of gathering it.
+    """
+    buf[:n, :].fill_(-1)
+
+
+@torch.compiler.disable
+def forward_hpu(self, hidden_states, q, k, weights):
+    """HPU SparseAttnIndexer: per-request QK BF16 scoring + torch.topk."""
+    forward_context = get_forward_context()
+    attn_metadata = forward_context.attn_metadata
+    kv_cache = self.k_cache.kv_cache
+    if isinstance(kv_cache, tuple):
+        kv_cache = kv_cache[0]
+    block_size = attn_metadata.block_size
+    slot_mapping = attn_metadata.slot_mapping.flatten()
+
+    if kv_cache is None or kv_cache.numel() == 0:
+        _fill_invalid(self.topk_indices_buffer, q.shape[0], q.device)
+        return self.topk_indices_buffer
+
+    if not self.skip_k_cache_insert:
+        kv_cache.index_copy_(0, slot_mapping[:k.shape[0]], k)
+
+    if attn_metadata.is_prompt:
+        _fill_invalid(self.topk_indices_buffer, q.shape[0], q.device)
+        return self.topk_indices_buffer
+
+    batch_size = q.shape[0]
+    block_list = attn_metadata.block_list
+    block_groups = attn_metadata.block_groups
+    block_usage = attn_metadata.block_usage
+
+    if block_list is None or block_groups is None or block_usage is None:
+        # No block-table metadata available for decode (unexpected); fall back
+        # to the sentinel fill so shapes stay valid instead of crashing.
+        _fill_invalid(self.topk_indices_buffer, batch_size, q.device)
+        return self.topk_indices_buffer
+
+    pos_range = torch.arange(block_size, device=block_list.device)
+    # block_usage is stored in model dtype (see hpu_model_runner.py); round to
+    # get an exact per-block valid-token count.
+    block_usage_long = block_usage.round().long()
+
+    for i in range(batch_size):
+        # Select this request's physical blocks directly via block_groups
+        # rather than assuming block_list is an unpadded per-request
+        # concatenation: with contiguous PA, blocks are scattered/reordered by
+        # physical block id, not laid out sequentially per request.
+        request_mask = block_groups == i
+        request_blocks = block_list[request_mask]
+        if request_blocks.numel() == 0:
+            self.topk_indices_buffer[i] = -1
+            continue
+        request_usage = block_usage_long[request_mask]
+
+        all_slots = (request_blocks.unsqueeze(1) * block_size + pos_range.unsqueeze(0)).reshape(-1)
+        valid_mask = (pos_range.unsqueeze(0) < request_usage.unsqueeze(1)).reshape(-1)
+        valid_slots = all_slots[valid_mask]
+        seq_len = valid_slots.shape[0]
+
+        if seq_len == 0:
+            self.topk_indices_buffer[i] = -1
+            continue
+
+        if seq_len <= self.topk_tokens:
+            self.topk_indices_buffer[i, :seq_len] = valid_slots
+            if seq_len < self.topk_tokens:
+                self.topk_indices_buffer[i, seq_len:] = -1
+            continue
+
+        k_all = kv_cache[valid_slots].to(torch.float32)
+        q_i = q[i].to(torch.float32)
+        logits = torch.mm(q_i.reshape(q_i.shape[0], -1), k_all.T)
+        scores = (torch.sigmoid(logits) * weights[i].to(torch.float32).unsqueeze(-1)).sum(0)
+        _, local_indices = torch.topk(scores, self.topk_tokens)
+        self.topk_indices_buffer[i] = valid_slots[local_indices]
+
+    return self.topk_indices_buffer

vllm_gaudi/platform.py

@@ -87,8 +87,7 @@ def get_attn_backend_cls(
         if attn_selector_config.use_sparse:
             if not attn_selector_config.use_mla:
                 raise NotImplementedError("Sparse Attention is not supported on HPU.")
-            logger.warning("Sparse attention (DSA) is not implemented on HPU; running DSA layers as dense MLA "
-                           "(exact for sequences up to index_topk tokens, approximate beyond).")
+            logger.info("Using HPU DSA (Dynamic Sparse Attention) with BF16 indexer.")
 
         if attn_selector_config.use_mla:
             logger.info("Using HPUAttentionMLA backend.")
@@ -99,6 +98,10 @@ def get_attn_backend_cls(
         return ("vllm_gaudi.v1.attention.backends."
                 "hpu_attn.HPUAttentionBackendV1")
 
+    @classmethod
+    def check_runner_kv_caches_multi_layer(cls) -> None:
+        pass  # DSA indexer cache shares layer index with MLA attention
+
     @classmethod
     def is_async_output_supported(cls, enforce_eager: Optional[bool]) -> bool:
         return True

vllm_gaudi/v1/worker/hpu_model_runner.py

@@ -1772,6 +1772,10 @@ def get_kv_cache_spec(self) -> dict[str, KVCacheSpec]:
                     dtype=self.kv_cache_dtype,
                     cache_dtype_str=cache_dtype_str,
                 )
+            elif isinstance(attn_module, AttentionLayerBase):
+                spec = attn_module.get_kv_cache_spec(self.vllm_config)
+                if spec is not None:
+                    kv_cache_spec[layer_name] = spec
 
         return kv_cache_spec