CVS-178227 : Fix tensor data access for OpenVINO 2026.0 compatibility

onnxruntime/core/providers/openvino/ov_allocator.cc

@@ -29,8 +29,10 @@ void* OVRTAllocator::Alloc(size_t size) {
     ov::Tensor* tensor = new ov::Tensor(remote_ctx_.create_host_tensor(ov::element::Type_t::u8,
                                                                        {size}));
     std::lock_guard<std::mutex> lock(mutex_);
-    allocated_.insert({tensor->data(), tensor});
-    return reinterpret_cast<void*>(tensor->data());
+    // Use raw data() accessor for OV 2026.0 compatibility
+    void* ptr = const_cast<void*>(static_cast<const ov::Tensor&>(*tensor).data());
+    allocated_.insert({ptr, tensor});
+    return ptr;
   } catch (const ov::Exception& e) {
     ORT_THROW(std::string("Alloc failed: ") + e.what());
   }

onnxruntime/core/providers/openvino/ov_bin_manager.cc

@@ -19,7 +19,9 @@ static inline uint64_t AlignUp(uint64_t value, uint64_t alignment) {
 class TensorStreamBuf : public std::streambuf {
  public:
   explicit TensorStreamBuf(ov::Tensor& tensor) {
-    char* data = const_cast<char*>(tensor.data<char>());
+    // Use raw data() accessor since memory-mapped tensors are read-only in OV 2026.0
+    // The templated data<T>() method is not allowed on read-only tensors
+    char* data = static_cast<char*>(const_cast<void*>(static_cast<const ov::Tensor&>(tensor).data()));
     size_t size = tensor.get_byte_size();
     setg(data, data, data + size);
   }
@@ -170,10 +172,12 @@ ov::Tensor BinManager::GetNativeBlob(const std::string& blob_name) {
 
   if (mapped_bin_) {
     // Create a tensor from memory-mapped external file
+    // Use raw data() accessor since memory-mapped tensors are read-only in OV 2026.0
+    // The templated data<T>() method is not allowed on read-only tensors
     blob_container.tensor = ov::Tensor(
         ov::element::u8,
         ov::Shape{blob_container.serialized_info.size},
-        mapped_bin_.data<uint8_t>() + blob_container.serialized_info.file_offset);
+        static_cast<uint8_t*>(const_cast<void*>(static_cast<const ov::Tensor&>(mapped_bin_).data())) + blob_container.serialized_info.file_offset);
   } else {
     // Create a tensor from embedded data vector
     blob_container.tensor = ov::Tensor(

onnxruntime/core/providers/openvino/ov_shared_context.cc

@@ -54,7 +54,9 @@ void* SharedContext::WeightsFile::TryGetOrCreateDeviceMapping(std::optional<ov::
     } else if (dev_name.empty()) {
       // CPU/virtual device case, create a CPU tensor memory mapped from file
       auto&& mmaped_tensor = ov::read_tensor_data(file_path_);
-      it->second = MappingContainer{.ptr_ = mmaped_tensor.data(), .tensor_ = mmaped_tensor};
+      // Use raw data() accessor since memory-mapped tensors are read-only in OV 2026.0
+      // The templated data<T>() method is not allowed on read-only tensors
+      it->second = MappingContainer{.ptr_ = const_cast<void*>(static_cast<const ov::Tensor&>(mmaped_tensor).data()), .tensor_ = mmaped_tensor};
     }
   }
 
@@ -85,7 +87,11 @@ void SharedContext::LoadTensorFromFile(
     // Can't mmap the file to device tensor, create a host tensor and copy the data
     tensor = remote_context->create_host_tensor(element_type, dimensions);
     ORT_ENFORCE(tensor.get_byte_size() == value.serialized.size, "Remote tensor size mismatch");
-    weights_file->LoadWeights(value.serialized.data_offset, tensor.data(), value.serialized.size);
+    // Use raw data() accessor for sub-byte types (i4, u4) compatibility in OV 2026.0
+    // The templated data<T>() method fails is_pointer_representable check for sub-byte types
+    weights_file->LoadWeights(value.serialized.data_offset,
+                              const_cast<void*>(static_cast<const ov::Tensor&>(tensor).data()),
+                              value.serialized.size);
   }
 
   ORT_ENFORCE(tensor.get_byte_size() == value.serialized.size, "Tensor size mismatch");