update

src/diffusers/models/attention_dispatch.py

@@ -38,7 +38,6 @@ from ..utils import (
     is_flash_attn_available,
     is_flash_attn_version,
     is_kernels_available,
-    is_kernels_version,
     is_sageattention_available,
     is_sageattention_version,
     is_torch_npu_available,
@@ -266,41 +265,28 @@ class _HubKernelConfig:
     repo_id: str
     function_attr: str
     revision: str | None = None
-    version: int | None = None
     kernel_fn: Callable | None = None
-    wrapped_forward_attr: str | None = None
-    wrapped_backward_attr: str | None = None
-    wrapped_forward_fn: Callable | None = None
-    wrapped_backward_fn: Callable | None = None
 
 
 # Registry for hub-based attention kernels
 _HUB_KERNELS_REGISTRY: dict["AttentionBackendName", _HubKernelConfig] = {
+    # TODO: temporary revision for now. Remove when merged upstream into `main`.
     AttentionBackendName._FLASH_3_HUB: _HubKernelConfig(
-        repo_id="kernels-community/flash-attn3", function_attr="flash_attn_func", version=1
+        repo_id="kernels-community/flash-attn3", function_attr="flash_attn_func", revision="fake-ops-return-probs"
     ),
     AttentionBackendName._FLASH_3_VARLEN_HUB: _HubKernelConfig(
         repo_id="kernels-community/flash-attn3",
         function_attr="flash_attn_varlen_func",
-        version=1,
+        # revision="fake-ops-return-probs",
     ),
     AttentionBackendName.FLASH_HUB: _HubKernelConfig(
-        repo_id="kernels-community/flash-attn2",
-        function_attr="flash_attn_func",
-        version=1,
-        revision=None,
-        wrapped_forward_attr="flash_attn_interface._wrapped_flash_attn_forward",
-        wrapped_backward_attr="flash_attn_interface._wrapped_flash_attn_backward",
+        repo_id="kernels-community/flash-attn2", function_attr="flash_attn_func", revision=None
     ),
     AttentionBackendName.FLASH_VARLEN_HUB: _HubKernelConfig(
-        repo_id="kernels-community/flash-attn2",
-        function_attr="flash_attn_varlen_func",
-        version=1,
+        repo_id="kernels-community/flash-attn2", function_attr="flash_attn_varlen_func", revision=None
     ),
     AttentionBackendName.SAGE_HUB: _HubKernelConfig(
-        repo_id="kernels-community/sage-attention",
-        function_attr="sageattn",
-        version=1,
+        repo_id="kernels-community/sage_attention", function_attr="sageattn", revision=None
     ),
 }
 
@@ -470,10 +456,6 @@ def _check_attention_backend_requirements(backend: AttentionBackendName) -> None
             raise RuntimeError(
                 f"Backend '{backend.value}' is not usable because the `kernels` package isn't available. Please install it with `pip install kernels`."
             )
-        if not is_kernels_version(">=", "0.12"):
-            raise RuntimeError(
-                f"Backend '{backend.value}' needs to be used with a `kernels` version of at least 0.12. Please update with `pip install -U kernels`."
-            )
 
     elif backend == AttentionBackendName.AITER:
         if not _CAN_USE_AITER_ATTN:
@@ -623,39 +605,22 @@ def _flex_attention_causal_mask_mod(batch_idx, head_idx, q_idx, kv_idx):
 
 
 # ===== Helpers for downloading kernels =====
-def _resolve_kernel_attr(module, attr_path: str):
-    target = module
-    for attr in attr_path.split("."):
-        if not hasattr(target, attr):
-            raise AttributeError(f"Kernel module '{module.__name__}' does not define attribute path '{attr_path}'.")
-        target = getattr(target, attr)
-    return target
-
-
 def _maybe_download_kernel_for_backend(backend: AttentionBackendName) -> None:
     if backend not in _HUB_KERNELS_REGISTRY:
         return
     config = _HUB_KERNELS_REGISTRY[backend]
 
-    needs_kernel = config.kernel_fn is None
-    needs_wrapped_forward = config.wrapped_forward_attr is not None and config.wrapped_forward_fn is None
-    needs_wrapped_backward = config.wrapped_backward_attr is not None and config.wrapped_backward_fn is None
-
-    if not (needs_kernel or needs_wrapped_forward or needs_wrapped_backward):
+    if config.kernel_fn is not None:
         return
 
     try:
         from kernels import get_kernel
 
         kernel_module = get_kernel(config.repo_id, revision=config.revision)
-        if needs_kernel:
-            config.kernel_fn = _resolve_kernel_attr(kernel_module, config.function_attr)
+        kernel_func = getattr(kernel_module, config.function_attr)
 
-        if needs_wrapped_forward:
-            config.wrapped_forward_fn = _resolve_kernel_attr(kernel_module, config.wrapped_forward_attr)
-
-        if needs_wrapped_backward:
-            config.wrapped_backward_fn = _resolve_kernel_attr(kernel_module, config.wrapped_backward_attr)
+        # Cache the downloaded kernel function in the config object
+        config.kernel_fn = kernel_func
 
     except Exception as e:
         logger.error(f"An error occurred while fetching kernel '{config.repo_id}' from the Hub: {e}")
@@ -1106,237 +1071,6 @@ def _flash_attention_backward_op(
     return grad_query, grad_key, grad_value
 
 
-def _flash_attention_hub_forward_op(
-    ctx: torch.autograd.function.FunctionCtx,
-    query: torch.Tensor,
-    key: torch.Tensor,
-    value: torch.Tensor,
-    attn_mask: torch.Tensor | None = None,
-    dropout_p: float = 0.0,
-    is_causal: bool = False,
-    scale: float | None = None,
-    enable_gqa: bool = False,
-    return_lse: bool = False,
-    _save_ctx: bool = True,
-    _parallel_config: "ParallelConfig" | None = None,
-):
-    if attn_mask is not None:
-        raise ValueError("`attn_mask` is not yet supported for flash-attn hub kernels.")
-    if enable_gqa:
-        raise ValueError("`enable_gqa` is not yet supported for flash-attn hub kernels.")
-
-    config = _HUB_KERNELS_REGISTRY[AttentionBackendName.FLASH_HUB]
-    wrapped_forward_fn = config.wrapped_forward_fn
-    wrapped_backward_fn = config.wrapped_backward_fn
-    if wrapped_forward_fn is None or wrapped_backward_fn is None:
-        raise RuntimeError(
-            "Flash attention hub kernels must expose `_wrapped_flash_attn_forward` and `_wrapped_flash_attn_backward` "
-            "for context parallel execution."
-        )
-
-    if scale is None:
-        scale = query.shape[-1] ** (-0.5)
-
-    window_size = (-1, -1)
-    softcap = 0.0
-    alibi_slopes = None
-    deterministic = False
-    grad_enabled = any(x.requires_grad for x in (query, key, value))
-
-    if grad_enabled or (_parallel_config is not None and _parallel_config.context_parallel_config._world_size > 1):
-        dropout_p = dropout_p if dropout_p > 0 else 1e-30
-
-    with torch.set_grad_enabled(grad_enabled):
-        out, lse, S_dmask, rng_state = wrapped_forward_fn(
-            query,
-            key,
-            value,
-            dropout_p,
-            scale,
-            is_causal,
-            window_size[0],
-            window_size[1],
-            softcap,
-            alibi_slopes,
-            return_lse,
-        )
-        lse = lse.permute(0, 2, 1).contiguous()
-
-    if _save_ctx:
-        ctx.save_for_backward(query, key, value, out, lse, rng_state)
-        ctx.dropout_p = dropout_p
-        ctx.scale = scale
-        ctx.is_causal = is_causal
-        ctx.window_size = window_size
-        ctx.softcap = softcap
-        ctx.alibi_slopes = alibi_slopes
-        ctx.deterministic = deterministic
-
-    return (out, lse) if return_lse else out
-
-
-def _flash_attention_hub_backward_op(
-    ctx: torch.autograd.function.FunctionCtx,
-    grad_out: torch.Tensor,
-    *args,
-    **kwargs,
-):
-    config = _HUB_KERNELS_REGISTRY[AttentionBackendName.FLASH_HUB]
-    wrapped_backward_fn = config.wrapped_backward_fn
-    if wrapped_backward_fn is None:
-        raise RuntimeError(
-            "Flash attention hub kernels must expose `_wrapped_flash_attn_backward` for context parallel execution."
-        )
-
-    query, key, value, out, lse, rng_state = ctx.saved_tensors
-    grad_query, grad_key, grad_value = torch.empty_like(query), torch.empty_like(key), torch.empty_like(value)
-
-    _ = wrapped_backward_fn(
-        grad_out,
-        query,
-        key,
-        value,
-        out,
-        lse,
-        grad_query,
-        grad_key,
-        grad_value,
-        ctx.dropout_p,
-        ctx.scale,
-        ctx.is_causal,
-        ctx.window_size[0],
-        ctx.window_size[1],
-        ctx.softcap,
-        ctx.alibi_slopes,
-        ctx.deterministic,
-        rng_state,
-    )
-
-    grad_query = grad_query[..., : grad_out.shape[-1]]
-    grad_key = grad_key[..., : grad_out.shape[-1]]
-    grad_value = grad_value[..., : grad_out.shape[-1]]
-
-    return grad_query, grad_key, grad_value
-
-
-def _flash_attention_3_hub_forward_op(
-    ctx: torch.autograd.function.FunctionCtx,
-    query: torch.Tensor,
-    key: torch.Tensor,
-    value: torch.Tensor,
-    attn_mask: torch.Tensor | None = None,
-    dropout_p: float = 0.0,
-    is_causal: bool = False,
-    scale: float | None = None,
-    enable_gqa: bool = False,
-    return_lse: bool = False,
-    _save_ctx: bool = True,
-    _parallel_config: "ParallelConfig" | None = None,
-    *,
-    window_size: tuple[int, int] = (-1, -1),
-    softcap: float = 0.0,
-    num_splits: int = 1,
-    pack_gqa: bool | None = None,
-    deterministic: bool = False,
-    sm_margin: int = 0,
-):
-    if attn_mask is not None:
-        raise ValueError("`attn_mask` is not yet supported for flash-attn 3 hub kernels.")
-    if dropout_p != 0.0:
-        raise ValueError("`dropout_p` is not yet supported for flash-attn 3 hub kernels.")
-    if enable_gqa:
-        raise ValueError("`enable_gqa` is not yet supported for flash-attn 3 hub kernels.")
-
-    func = _HUB_KERNELS_REGISTRY[AttentionBackendName._FLASH_3_HUB].kernel_fn
-    out = func(
-        q=query,
-        k=key,
-        v=value,
-        softmax_scale=scale,
-        causal=is_causal,
-        qv=None,
-        q_descale=None,
-        k_descale=None,
-        v_descale=None,
-        window_size=window_size,
-        softcap=softcap,
-        num_splits=num_splits,
-        pack_gqa=pack_gqa,
-        deterministic=deterministic,
-        sm_margin=sm_margin,
-        return_attn_probs=return_lse,
-    )
-
-    lse = None
-    if return_lse:
-        out, lse = out
-        lse = lse.permute(0, 2, 1).contiguous()
-
-    if _save_ctx:
-        ctx.save_for_backward(query, key, value)
-        ctx.scale = scale
-        ctx.is_causal = is_causal
-        ctx._hub_kernel = func
-
-    return (out, lse) if return_lse else out
-
-
-def _flash_attention_3_hub_backward_op(
-    ctx: torch.autograd.function.FunctionCtx,
-    grad_out: torch.Tensor,
-    *args,
-    window_size: tuple[int, int] = (-1, -1),
-    softcap: float = 0.0,
-    num_splits: int = 1,
-    pack_gqa: bool | None = None,
-    deterministic: bool = False,
-    sm_margin: int = 0,
-):
-    query, key, value = ctx.saved_tensors
-    kernel_fn = ctx._hub_kernel
-    # NOTE: Unlike the FA2 hub kernel, the FA3 hub kernel does not expose separate wrapped forward/backward
-    # primitives (no `wrapped_forward_attr`/`wrapped_backward_attr` in its `_HubKernelConfig`). We
-    # therefore rerun the forward pass under `torch.enable_grad()` and differentiate through it with
-    # `torch.autograd.grad()`. This is a second forward pass during backward; it can be avoided once
-    # the FA3 hub exposes a dedicated fused backward kernel (analogous to `_wrapped_flash_attn_backward`
-    # in the FA2 hub), at which point this can be refactored to match `_flash_attention_hub_backward_op`.
-    with torch.enable_grad():
-        query_r = query.detach().requires_grad_(True)
-        key_r = key.detach().requires_grad_(True)
-        value_r = value.detach().requires_grad_(True)
-
-        out = kernel_fn(
-            q=query_r,
-            k=key_r,
-            v=value_r,
-            softmax_scale=ctx.scale,
-            causal=ctx.is_causal,
-            qv=None,
-            q_descale=None,
-            k_descale=None,
-            v_descale=None,
-            window_size=window_size,
-            softcap=softcap,
-            num_splits=num_splits,
-            pack_gqa=pack_gqa,
-            deterministic=deterministic,
-            sm_margin=sm_margin,
-            return_attn_probs=False,
-        )
-        if isinstance(out, tuple):
-            out = out[0]
-
-        grad_query, grad_key, grad_value = torch.autograd.grad(
-            out,
-            (query_r, key_r, value_r),
-            grad_out,
-            retain_graph=False,
-            allow_unused=False,
-        )
-
-    return grad_query, grad_key, grad_value
-
-
 def _sage_attention_forward_op(
     ctx: torch.autograd.function.FunctionCtx,
     query: torch.Tensor,
@@ -1375,46 +1109,6 @@ def _sage_attention_forward_op(
     return (out, lse) if return_lse else out
 
 
-def _sage_attention_hub_forward_op(
-    ctx: torch.autograd.function.FunctionCtx,
-    query: torch.Tensor,
-    key: torch.Tensor,
-    value: torch.Tensor,
-    attn_mask: torch.Tensor | None = None,
-    dropout_p: float = 0.0,
-    is_causal: bool = False,
-    scale: float | None = None,
-    enable_gqa: bool = False,
-    return_lse: bool = False,
-    _save_ctx: bool = True,
-    _parallel_config: "ParallelConfig" | None = None,
-):
-    if attn_mask is not None:
-        raise ValueError("`attn_mask` is not yet supported for Sage attention.")
-    if dropout_p > 0.0:
-        raise ValueError("`dropout_p` is not yet supported for Sage attention.")
-    if enable_gqa:
-        raise ValueError("`enable_gqa` is not yet supported for Sage attention.")
-
-    func = _HUB_KERNELS_REGISTRY[AttentionBackendName.SAGE_HUB].kernel_fn
-    out = func(
-        q=query,
-        k=key,
-        v=value,
-        tensor_layout="NHD",
-        is_causal=is_causal,
-        sm_scale=scale,
-        return_lse=return_lse,
-    )
-
-    lse = None
-    if return_lse:
-        out, lse, *_ = out
-        lse = lse.permute(0, 2, 1).contiguous()
-
-    return (out, lse) if return_lse else out
-
-
 def _sage_attention_backward_op(
     ctx: torch.autograd.function.FunctionCtx,
     grad_out: torch.Tensor,
@@ -2271,7 +1965,7 @@ def _flash_attention(
 @_AttentionBackendRegistry.register(
     AttentionBackendName.FLASH_HUB,
     constraints=[_check_device, _check_qkv_dtype_bf16_or_fp16, _check_shape],
-    supports_context_parallel=True,
+    supports_context_parallel=False,
 )
 def _flash_attention_hub(
     query: torch.Tensor,
@@ -2289,35 +1983,17 @@ def _flash_attention_hub(
         raise ValueError("`attn_mask` is not supported for flash-attn 2.")
 
     func = _HUB_KERNELS_REGISTRY[AttentionBackendName.FLASH_HUB].kernel_fn
-    if _parallel_config is None:
-        out = func(
-            q=query,
-            k=key,
-            v=value,
-            dropout_p=dropout_p,
-            softmax_scale=scale,
-            causal=is_causal,
-            return_attn_probs=return_lse,
-        )
-        if return_lse:
-            out, lse, *_ = out
-    else:
-        out = _templated_context_parallel_attention(
-            query,
-            key,
-            value,
-            None,
-            dropout_p,
-            is_causal,
-            scale,
-            False,
-            return_lse,
-            forward_op=_flash_attention_hub_forward_op,
-            backward_op=_flash_attention_hub_backward_op,
-            _parallel_config=_parallel_config,
-        )
-        if return_lse:
-            out, lse = out
+    out = func(
+        q=query,
+        k=key,
+        v=value,
+        dropout_p=dropout_p,
+        softmax_scale=scale,
+        causal=is_causal,
+        return_attn_probs=return_lse,
+    )
+    if return_lse:
+        out, lse, *_ = out
 
     return (out, lse) if return_lse else out
 
@@ -2464,7 +2140,7 @@ def _flash_attention_3(
 @_AttentionBackendRegistry.register(
     AttentionBackendName._FLASH_3_HUB,
     constraints=[_check_device, _check_qkv_dtype_bf16_or_fp16, _check_shape],
-    supports_context_parallel=True,
+    supports_context_parallel=False,
 )
 def _flash_attention_3_hub(
     query: torch.Tensor,
@@ -2479,68 +2155,33 @@ def _flash_attention_3_hub(
     return_attn_probs: bool = False,
     _parallel_config: "ParallelConfig" | None = None,
 ) -> torch.Tensor:
+    if _parallel_config:
+        raise NotImplementedError(f"{AttentionBackendName._FLASH_3_HUB.value} is not implemented for parallelism yet.")
     if attn_mask is not None:
         raise ValueError("`attn_mask` is not supported for flash-attn 3.")
 
     func = _HUB_KERNELS_REGISTRY[AttentionBackendName._FLASH_3_HUB].kernel_fn
-    if _parallel_config is None:
-        out = func(
-            q=query,
-            k=key,
-            v=value,
-            softmax_scale=scale,
-            causal=is_causal,
-            qv=None,
-            q_descale=None,
-            k_descale=None,
-            v_descale=None,
-            window_size=window_size,
-            softcap=softcap,
-            num_splits=1,
-            pack_gqa=None,
-            deterministic=deterministic,
-            sm_margin=0,
-            return_attn_probs=return_attn_probs,
-        )
-        return (out[0], out[1]) if return_attn_probs else out
-
-    forward_op = functools.partial(
-        _flash_attention_3_hub_forward_op,
+    out = func(
+        q=query,
+        k=key,
+        v=value,
+        softmax_scale=scale,
+        causal=is_causal,
+        qv=None,
+        q_descale=None,
+        k_descale=None,
+        v_descale=None,
         window_size=window_size,
         softcap=softcap,
         num_splits=1,
         pack_gqa=None,
         deterministic=deterministic,
         sm_margin=0,
+        return_attn_probs=return_attn_probs,
     )
-    backward_op = functools.partial(
-        _flash_attention_3_hub_backward_op,
-        window_size=window_size,
-        softcap=softcap,
-        num_splits=1,
-        pack_gqa=None,
-        deterministic=deterministic,
-        sm_margin=0,
-    )
-    out = _templated_context_parallel_attention(
-        query,
-        key,
-        value,
-        None,
-        0.0,
-        is_causal,
-        scale,
-        False,
-        return_attn_probs,
-        forward_op=forward_op,
-        backward_op=backward_op,
-        _parallel_config=_parallel_config,
-    )
-    if return_attn_probs:
-        out, lse = out
-        return out, lse
-
-    return out
+    # When `return_attn_probs` is True, the above returns a tuple of
+    # actual outputs and lse.
+    return (out[0], out[1]) if return_attn_probs else out
 
 
 @_AttentionBackendRegistry.register(
@@ -3172,7 +2813,7 @@ def _sage_attention(
 @_AttentionBackendRegistry.register(
     AttentionBackendName.SAGE_HUB,
     constraints=[_check_device_cuda, _check_qkv_dtype_bf16_or_fp16, _check_shape],
-    supports_context_parallel=True,
+    supports_context_parallel=False,
 )
 def _sage_attention_hub(
     query: torch.Tensor,
@@ -3200,23 +2841,6 @@ def _sage_attention_hub(
         )
         if return_lse:
             out, lse, *_ = out
-    else:
-        out = _templated_context_parallel_attention(
-            query,
-            key,
-            value,
-            None,
-            0.0,
-            is_causal,
-            scale,
-            False,
-            return_lse,
-            forward_op=_sage_attention_hub_forward_op,
-            backward_op=_sage_attention_backward_op,
-            _parallel_config=_parallel_config,
-        )
-        if return_lse:
-            out, lse = out
 
     return (out, lse) if return_lse else out
 

src/diffusers/utils/__init__.py

@@ -86,7 +86,6 @@ from .import_utils import (
     is_inflect_available,
     is_invisible_watermark_available,
     is_kernels_available,
-    is_kernels_version,
     is_kornia_available,
     is_librosa_available,
     is_matplotlib_available,

src/diffusers/utils/import_utils.py

@@ -724,22 +724,6 @@ def is_transformers_version(operation: str, version: str):
     return compare_versions(parse(_transformers_version), operation, version)
 
 
-@cache
-def is_kernels_version(operation: str, version: str):
-    """
-    Compares the current Kernels version to a given reference with an operation.
-
-    Args:
-        operation (`str`):
-            A string representation of an operator, such as `">"` or `"<="`
-        version (`str`):
-            A version string
-    """
-    if not _kernels_available:
-        return False
-    return compare_versions(parse(_kernels_version), operation, version)
-
-
 @cache
 def is_hf_hub_version(operation: str, version: str):
     """

tests/models/testing_utils/lora.py

@@ -375,7 +375,7 @@ class LoraHotSwappingForModelTesterMixin:
             # additionally check if dynamic compilation works.
             if different_shapes is not None:
                 for height, width in different_shapes:
-                    new_inputs_dict = self.prepare_dummy_input(height=height, width=width)
+                    new_inputs_dict = self.get_dummy_inputs(height=height, width=width)
                     _ = model(**new_inputs_dict)
             else:
                 output0_after = model(**inputs_dict)["sample"]
@@ -390,7 +390,7 @@ class LoraHotSwappingForModelTesterMixin:
         with torch.inference_mode():
             if different_shapes is not None:
                 for height, width in different_shapes:
-                    new_inputs_dict = self.prepare_dummy_input(height=height, width=width)
+                    new_inputs_dict = self.get_dummy_inputs(height=height, width=width)
                     _ = model(**new_inputs_dict)
             else:
                 output1_after = model(**inputs_dict)["sample"]