[GPU] Add Level Zero - OpenCL interoperability (#36014)

### Details:
 - Detect if current system supports interoperability. 
- If check is passed, then create OCL remote context over L0 GPU
runtime.
   - If check fails, then create L0 remote context over L0 GPU runtime.
- Remote context and remote tensors query internal GPU plugin objects
fur runtime specific handles.
   - OCL remote context will query for OCL handles.
   - L0 remote context will query for L0 handles.
- Enable L0 internal GPU plugin objects to return converted OCL handles.
 - Add `resource_owner` template for gpu resource management.
- Add `ze_resource` template that will hold Level Zero objects and
optionally corresponding OpenCL objects.
- Add operators for conversion between Level Zero objects and OpenCL
objects.

### Benchmarks:
Peak memory usage measured on benchmark_app running resnet-50 on BMG
Linux
|  | VmPeak (kB) | MaxRSS (kB) |
| --- | --- | --- |
| This PR (runtime=L0, interop=ON) | 3,262,536 | 190,924 |
| This PR (runtime=L0, interop=OFF) | 3,263,688 | 193,200 |
| Master (runtime=L0) | 3,293,048 | 192,188 |
| [REF] Master (runtime=OCL) | 3,281,412 | 193,196 |

### Tickets:
 - [CVS-185378](https://jira.devtools.intel.com/browse/CVS-185378)

### AI Assistance:
 - AI assistance used: yes
 - AI help was used to create tests

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: jkasprza

src/inference/include/openvino/runtime/intel_gpu/remote_properties.hpp

@@ -30,7 +30,7 @@ using os_handle_param = void*;
 enum class ContextType {
     OCL = 0,        //!< Pure OpenCL context
     VA_SHARED = 1,  //!< Context shared with a video decoding device
-    ZE = 2,         //!< Pure Level0 context
+    ZE = 2,         //!< Pure Level Zero context
 };
 
 /** @cond INTERNAL */
@@ -52,10 +52,10 @@ inline std::istream& operator>>(std::istream& is, ContextType& context_type) {
     is >> str;
     if (str == "OCL") {
         context_type = ContextType::OCL;
-    } else if (str == "ZE") {
-        context_type = ContextType::ZE;
     } else if (str == "VA_SHARED") {
         context_type = ContextType::VA_SHARED;
+    } else if (str == "ZE") {
+        context_type = ContextType::ZE;
     } else {
         OPENVINO_THROW("Unsupported context type: ", str);
     }

src/plugins/intel_gpu/docs/blog/ze_ocl_interop_2026_3.md

@@ -0,0 +1,50 @@
+# Support for Level Zero - OpenCL interoperability: New in OpenVINO 2026.3
+
+*By Jakub Kasprzak | June 23, 2026*
+
+Some projects maintain their own OpenCL GPU pipeline and require features such as memory, context or queue sharing. For such users OpenVINO GPU plugin implements Remote Context and Remote Tensor interface. However, this OpenCL interoperability works only if OpenVINO GPU runtime is set to OpenCL and prevents OpenVINO from switching to Level Zero runtime.
+OpenVINO 2026.3 introduces Level Zero - OpenCL interoperability enabling users that depend on OpenVINO Remote Context/Tensor OpenCL API to swap OpenVINO GPU runtime to Level Zero without changing their OpenCL based integration logic. This post explains: how to enable this feature and provides OpenVINO maintainers with design description.
+
+## How to enable Level Zero - OpenCL interoperability
+
+OpenVINO GPU plugin with Level Zero runtime detects if interoperability is supported on current system and enables it automatically. User must ensure that currently installed Intel GPU driver supports and enables "Level Zero executing OpenCL" (LEO) feature.
+
+## Level Zero - OpenCL interoperability design
+
+*This section describes internal design of the feature and is intended for OpenVINO maintainers*
+
+### Object lifetimes
+
+This subsection describes part of the design responsible for managing resources. Main goal was to provide modular API that will minimize chances of memory leaks and other memory bugs.
+
+Logic for managing all (Level Zero and OpenCL) GPU resources is provided by `resource_owner` template class. It contains `is_borrowed` flag to distinguish between resources that need to be released and resources that should not be released (borrowed resources, for example: external memory buffers provided by the user). Once `resource_owner` is destroyed it will release the resource or do nothing if resource was borrowed. Basically `resource_owner` with `is_borrowed=false` is a generic RAII wrapper which means that only one such object can exist for a given resource and that it can not be copied (only move semantics are allowed).
+
+In order to work correctly `resource_owner` template must be provided with information about the type of resource it manages and how to release it. This information is defined for Level Zero and OpenCL resources in `ze_resource_info` and `ocl_resource_info` class template specializations respectively. For example `ocl_resource_info<ocl_resource_type::command_queue>` defines `handle_t` as `cl_command_queue` and `deleter_t` as a functor that calls `clReleaseCommandQueue`. Finally `ze_owner` and `ocl_owner` aliases are defined by combining `resource_owner` with `ze_resource_info` and `ocl_resource_info` respectively.
+
+### Binding corresponding Level Zero - OpenCL handles
+
+It is important to recognize that with interoperability some Level Zero handles will have corresponding OpenCL handles and vice versa. For example, after converting Level Zero immediate command list to OpenCL command queue we end up with two different handles referring to the same entity. `ze_ocl_owner_impl` is a template that is responsible for combining Level Zero handle with OpenCL handle and managing them as a single resource. Internally it contains `ze_owner` and tuple of optional `ocl_owner`s. By design `ze_ocl_owner_impl` always contains Level Zero resource and OpenCL resources can be attached to it. Once OpenCL resource of some given type is attached to `ze_ocl_owner_impl` attempt to attach another OpenCL resource of the same type will result in **exception** (this design is to prevent exporting single Level Zero resource multiple times).
+
+Not all handle combinations are valid. For example in current context it does not make sense to attach/bind `cl_command_queue` handle to `ze_ocl_owner_impl` that holds `ze_image_handle_t`. To prevent this `ze_ocl_owner` template inherits only valid `ze_ocl_owner_impl` specializations. For example `ze_ocl_owner<ze_resource_type::command_list>` is `ze_ocl_owner_impl<ze_resource_type::command_list, ocl_resource_type::command_queue>` meaning it holds `ze_command_list_handle_t` and optionally `cl_command_queue` handles. If specialization is not defined explicitly it fall backs to default implementation where only Level Zero handle is allowed, for example `ze_ocl_owner<ze_resource_type::kernel>` holds only `ze_kernel_handle_t` and attempt to attach or access any type of OpenCL handle will result in **compilation error**.
+
+### Shared resource ownership
+
+Finally `ze_resource` template combines `std::shared_ptr` and `ze_ocl_owner` to implement shared ownership model for GPU resources. This is especially useful for handling lifetime of Level Zero events and event pools where `ze_resource<ze_resource_type::event_pool>` can be copied to all event objects created from given pool ensuring that the pool resource will be destroyed only after last event from the pool was destroyed (same scheme is used to manage lifetime of Level Zero modules and kernels).
+
+Additionaly aliases in form of `ze_*_resource` such as `ze_event_pool_resource` are defined for developer convenience.
+
+### Interoperability integration
+
+Basic interoperability is implemented by a `ze_ocl_interop` singleton that detects interoperability support and provides direct (no abstraction) Level Zero - OpenCL handle to handle conversion interface. When `ze_ocl_interop` is accessed for the first time it will initialize GPU runtimes and map corresponding Level Zero and OpenCL devices.
+
+Conversion interface provided by `ze_ocl_interop` is wrapped by `ze_import_*` and `ze_export_ocl` functions from `ze_resource_interop.hpp` in order to simplify conversion logic when used with `ze_resource` objects. For example calling `ze_export_ocl_command_queue` for given `ze_command_list_resource` will:
+1. Return early if `ze_command_list_resource` already has attached OpenCL command queue handle
+2. Create new OpenCL command queue based on present Level Zero handle
+3. Attach new OpenCL handle to `ze_command_list_resource`
+4. Guarantee strong exception safety
+
+### Remote context
+
+Type of remote context decides what kind of objects are exposed by the GPU plugin. During model compilation OpenVINO creates remote context and internal engine that by default match currently selected GPU runtime. For example, when GPU runtime is set to Level Zero this causes the creation of Level Zero remote context and `ze_engine`. Remote context will query internal GPU plugin objects for handles based on the remote context type. So if Level Zero remote context is used only Level Zero handles can be requested from internal objects and OpenCL interoperability is not required.
+
+If user provides OpenCL context or queue or OpenVINO detects that current system supports Level Zero - OpenCL interoperability then remote context type will be changed to OpenCL but engine will still match currently selected GPU runtime. In result OpenCL remote context will request OpenCL handles from internal Level Zero GPU plugin objects like `ze_engine` forcing usage of interoperability features.

src/plugins/intel_gpu/include/intel_gpu/plugin/remote_context.hpp

@@ -95,11 +95,8 @@ class RemoteContextImpl : public ov::IRemoteContext {
     ov::intel_gpu::gpu_handle_param m_va_display = nullptr;
     ov::intel_gpu::gpu_handle_param m_external_queue = nullptr;
 
-#ifdef OV_GPU_WITH_ZE_RT
-    ContextType m_type = ContextType::ZE;
-#else
-    ContextType m_type = ContextType::OCL;
-#endif
+
+    ContextType m_type;
     std::string m_device_name = "";
     static const size_t cache_capacity = 100;
     cldnn::LruCache<size_t, cldnn::memory::ptr> m_memory_cache = cldnn::LruCache<size_t, cldnn::memory::ptr>(cache_capacity);

src/plugins/intel_gpu/include/intel_gpu/runtime/device_info.hpp

@@ -122,8 +122,9 @@ struct device_info {
     bool supports_usm;                          ///< Does engine support unified shared memory.
     bool has_separate_cache;                    ///< Does the target hardware has separate cache for usm_device and usm_host
 
-    bool supports_cp_offload;                   ///< [ZE] Does the command queue support copy offload
-    bool supports_counter_based_events;         ///< [ZE] Does the target runtime support counter based events
+    bool supports_cp_offload;                   ///< [L0] Does the command queue support copy offload
+    bool supports_counter_based_events;         ///< [L0] Does the target runtime support counter based events
+    bool supports_leo;                          ///< [L0] Does the device support Level Zero - OpenCL interoperability (LEO)
 
     std::vector<size_t> supported_simd_sizes;   ///< List of SIMD sizes supported by current device and compiler
 

src/plugins/intel_gpu/include/intel_gpu/runtime/device_query.hpp

@@ -17,11 +17,6 @@ namespace cldnn {
 struct device_query {
 public:
     static int device_id;
-    /// @brief Get default engine type
-    static engine_types get_default_engine_type();
-
-    /// @brief Get default runtime type
-    static runtime_types get_default_runtime_type();
 
     explicit device_query(engine_types engine_type,
                           runtime_types runtime_type,

src/plugins/intel_gpu/include/intel_gpu/runtime/engine.hpp

@@ -113,8 +113,8 @@ class engine {
     /// Returns device object associated with the engine
     const device::ptr get_device() const;
 
-    /// Returns user context handle which was used to create the engine
-    virtual void* get_user_context() const = 0;
+    /// Returns L0 or OpenCL user context handle which was used to create the engine.
+    virtual void* get_user_context(runtime_types rt_type) const = 0;
 
     /// Returns the total maximum amount of GPU memory allocated by engine in current process for all allocation types
     uint64_t get_max_used_device_memory() const;

src/plugins/intel_gpu/include/intel_gpu/runtime/engine_configuration.hpp

@@ -64,4 +64,10 @@ inline std::ostream& operator<<(std::ostream& os, const backend_types& type) {
     return os;
 }
 
+/// @brief Get default engine type
+engine_types get_default_engine_type();
+
+/// @brief Get default runtime type
+runtime_types get_default_runtime_type();
+
 }  // namespace cldnn

src/plugins/intel_gpu/include/intel_gpu/runtime/memory.hpp

@@ -58,7 +58,11 @@ struct memory {
 
     size_t size() const { return _bytes_count; }
     size_t count() const { return _layout.count(); }
-    virtual shared_mem_params get_internal_params() const = 0;
+    /// @brief Return internal params for specified runtime type
+    virtual shared_mem_params get_internal_params(runtime_types rt_type) const = 0;
+    shared_mem_params get_internal_params() const {
+        return get_internal_params(get_default_runtime_type());
+    }
     virtual bool is_allocated_by(const engine& engine) const { return &engine == _engine && _type != allocation_type::unknown; }
     engine* get_engine() const { return _engine; }
     const layout& get_layout() const { return _layout; }
@@ -156,7 +160,7 @@ struct simple_attached_memory : memory {
     void unlock(const stream& /* stream */) override {}
     event::ptr fill(stream& /* stream */, unsigned char, const std::vector<event::ptr>&, bool) override { return nullptr; }
     event::ptr fill(stream& /* stream */, const std::vector<event::ptr>&, bool) override { return nullptr; }
-    shared_mem_params get_internal_params() const override { return { shared_mem_type::shared_mem_empty, nullptr, nullptr, nullptr,
+    shared_mem_params get_internal_params(runtime_types rt_type) const override { return { shared_mem_type::shared_mem_empty, nullptr, nullptr, nullptr,
 #ifdef _WIN32
         nullptr,
 #else

src/plugins/intel_gpu/include/intel_gpu/runtime/memory_caps.hpp

@@ -110,7 +110,7 @@ using shared_surface = uint32_t;
 /// @brief Low-level API handles required for using cldnn memory objects in external API calls.
 struct shared_mem_params {
     shared_mem_type mem_type;     ///< shared buffer type
-    shared_handle context;        ///< OpenCL context for external operations
+    shared_handle context;        ///< OpenCL or Level Zero context for external operations
     shared_handle user_device;    ///< DX/VA device for external operations
     shared_handle mem;            ///< memory object handle
 #ifdef _WIN32

src/plugins/intel_gpu/src/plugin/remote_context.cpp

@@ -23,12 +23,29 @@ Type extract_object(const ov::AnyMap& params, const ov::Property<Type>& p) {
     return res.as<Type>();
 }
 
+ContextType get_default_context_type() {
+    #ifdef OV_GPU_WITH_ZE_RT
+        return ContextType::ZE;
+    #elif defined(OV_GPU_WITH_OCL_RT)
+        return ContextType::OCL;
+    #else
+        #error "Expected OpenVINO GPU runtime macros to be defined"
+    #endif
+}
+
 }  // namespace
 
 RemoteContextImpl::RemoteContextImpl(const std::string& device_name, std::vector<cldnn::device::ptr> devices, bool initialize_ctx)
     : m_device_name(device_name) {
     OPENVINO_ASSERT(devices.size() == 1, "[GPU] Currently context can be created for single device only");
     m_device = devices.front();
+    m_type = get_default_context_type();
+    const auto &info = m_device->get_info();
+    if (m_type == ContextType::ZE && info.supports_leo) {
+        m_type = ContextType::OCL;
+        GPU_DEBUG_INFO << "Enabled Level Zero - OpenCL interoperability for "
+            << m_device_name << " (" << info.dev_name << ")" << std::endl;
+    }
 
     if (initialize_ctx) {
         initialize();
@@ -39,6 +56,7 @@ RemoteContextImpl::RemoteContextImpl(const std::map<std::string, RemoteContextIm
     gpu_handle_param context_id = nullptr;
     int ctx_device_id = 0;
     int target_tile_id = -1;
+    m_type = get_default_context_type();
 
     if (params.size()) {
         auto ctx_type = extract_object(params, ov::intel_gpu::context_type);
@@ -56,20 +74,23 @@ RemoteContextImpl::RemoteContextImpl(const std::map<std::string, RemoteContextIm
         } else if (ctx_type == ov::intel_gpu::ContextType::VA_SHARED) {
             m_va_display = extract_object(params, ov::intel_gpu::va_device);
             OPENVINO_ASSERT(m_va_display != nullptr, "[GPU] Can't create shared VA/DX context as user handle is nullptr! Params:\n", params);
-            m_type = ContextType::VA_SHARED;
+        } else if (ctx_type == ov::intel_gpu::ContextType::ZE) {
+            OPENVINO_THROW("Level Zero interoperability is not supported");
         } else {
             OPENVINO_THROW("Invalid execution context type", ctx_type);
         }
+        m_type = ctx_type;
         if (params.find(ov::intel_gpu::tile_id.name()) != params.end()) {
             target_tile_id = extract_object(params, ov::intel_gpu::tile_id);
         }
     }
 
     const auto initialize_devices = true;
 
-    cldnn::device_query device_query(context_id, m_va_display, ctx_device_id, target_tile_id, initialize_devices);
-    auto device_map = device_query.get_available_devices();
-
+    // Always use OCL for device query
+    // Query will return devices compatible with default runtime
+    cldnn::device_query ocl_device_query(cldnn::engine_types::ocl, cldnn::runtime_types::ocl, context_id, m_va_display, ctx_device_id, target_tile_id, initialize_devices);
+    auto device_map = ocl_device_query.get_available_devices();
     OPENVINO_ASSERT(device_map.size() == 1, "[GPU] Exactly one device expected in case of context sharing, but ", device_map.size(), " found");
 
     m_device = device_map.begin()->second;
@@ -89,19 +110,20 @@ const cldnn::engine& RemoteContextImpl::get_engine() const {
 }
 
 void RemoteContextImpl::init_properties() {
-    properties = { ov::intel_gpu::ocl_context(m_engine->get_user_context()) };
-
     switch (m_type) {
     case ContextType::OCL:
         properties.insert(ov::intel_gpu::context_type(ov::intel_gpu::ContextType::OCL));
+        properties.insert(ov::intel_gpu::ocl_context(m_engine->get_user_context(cldnn::runtime_types::ocl)));
         properties.insert(ov::intel_gpu::ocl_queue(m_external_queue));
         break;
     case ContextType::VA_SHARED:
         properties.insert(ov::intel_gpu::context_type(ov::intel_gpu::ContextType::VA_SHARED));
+        properties.insert(ov::intel_gpu::ocl_context(m_engine->get_user_context(cldnn::runtime_types::ocl)));
         properties.insert(ov::intel_gpu::va_device(m_va_display));
         break;
     case ContextType::ZE:
         properties.insert(ov::intel_gpu::context_type(ov::intel_gpu::ContextType::ZE));
+        properties.insert(ov::intel_gpu::ocl_context(m_engine->get_user_context(cldnn::runtime_types::ze)));
         break;
     default:
         OPENVINO_THROW("[GPU] Unsupported shared context type ", m_type);
@@ -256,7 +278,7 @@ void RemoteContextImpl::initialize() {
 
         m_device->initialize();  // Initialize associated device before use
         m_engine = cldnn::engine::create(
-            cldnn::device_query::get_default_engine_type(), cldnn::device_query::get_default_runtime_type(), m_device);
+            cldnn::get_default_engine_type(), cldnn::get_default_runtime_type(), m_device);
 
         init_properties();