[XPU] Support XCCL on deepspeed side (#7299)

XCCL will be used for XPU device on Pytorch-2.8, with this support will
remove torch-ccl on XPU device, and we will also reserve the old path
for torch-CCL enable.

---------

Signed-off-by: yisheng <[email protected]>
Co-authored-by: Ma, Guokai <[email protected]>

Author: ys950902

accelerator/real_accelerator.py

@@ -136,6 +136,21 @@ def get_accelerator():
                     accelerator_name = "xpu"
             except ImportError as e:
                 pass
+        if accelerator_name is None:
+            try:
+                import torch
+
+                # torch.xpu will be supported in upstream pytorch-2.8.
+                # Currently we can run on xpu device only using pytorch,
+                # also reserve the old path using ipex when the torch version is old.
+                if hasattr(torch, 'xpu'):
+                    if torch.cuda.device_count() == 0:  #ignore-cuda
+                        if torch.xpu.device_count() > 0 and torch.xpu.is_available():
+                            accelerator_name = "xpu"
+                else:
+                    pass
+            except ImportError as e:
+                pass
         if accelerator_name is None:
             try:
                 import torch_npu  # noqa: F401,F811 # type: ignore

accelerator/xpu_accelerator.py

@@ -5,19 +5,32 @@
 
 import torch
 from deepspeed.accelerator.abstract_accelerator import DeepSpeedAccelerator
-import intel_extension_for_pytorch as ipex  # noqa: F401 # type: ignore
-import oneccl_bindings_for_pytorch  # noqa: F401 # type: ignore
 import functools
-
 import importlib
 import inspect
 
+try:
+    import oneccl_bindings_for_pytorch  # noqa: F401 # type: ignore
+    oneccl_imported_p = True
+except ImportError as e:
+    oneccl_imported_p = False
+
+try:
+    import intel_extension_for_pytorch as ipex  # noqa: F401 # type: ignore
+    ipex_imported_p = True
+except ImportError as e:
+    ipex_imported_p = False
+
 
 class XPU_Accelerator(DeepSpeedAccelerator):
 
     def __init__(self):
         self._name = 'xpu'
-        self._communication_backend_name = 'ccl'
+        if oneccl_imported_p:
+            self._communication_backend_name = 'ccl'
+        else:
+            # changed to xccl if not using torch-CCL on XPU device
+            self._communication_backend_name = 'xccl'
         self._compile_backend = "inductor"
         self.aligned_tensors = []
         self.class_dict = None
@@ -26,11 +39,14 @@ def is_synchronized_device(self):
         return False
 
     def use_host_timers(self):
-        # WA XPU event will be consolidated in 2.6
-        if ipex.__version__ < '2.6':
-            return True
-        else:
+        if not ipex_imported_p:
             return self.is_synchronized_device()
+        else:
+            # WA XPU event will be consolidated in 2.6
+            if ipex.__version__ < '2.6':
+                return True
+            else:
+                return self.is_synchronized_device()
 
     def resolves_data_dependency(self):
         return self.is_synchronized_device()
@@ -290,10 +306,13 @@ def get_op_builder(self, class_name):
             return self.class_dict['NotImplementedBuilder']
 
     def build_extension(self):
-        try:
-            from intel_extension_for_pytorch.xpu.cpp_extension import DpcppBuildExtension
-        except ImportError:
-            from intel_extension_for_pytorch.xpu.utils import DpcppBuildExtension
+        if ipex_imported_p:
+            try:
+                from intel_extension_for_pytorch.xpu.cpp_extension import DpcppBuildExtension
+            except ImportError:
+                from intel_extension_for_pytorch.xpu.utils import DpcppBuildExtension
+        else:
+            from torch.utils.cpp_extension import DpcppBuildExtension
         return DpcppBuildExtension
 
     def export_envs(self):