Update usage of zeCommandListImmediateAppendCommandListsExp to use dlsym

The implementation was using zeCommandListImmediateAppendCommandListsExp
directly with the loader. This creates an issue with old loaders that don't
support this entrypoint. Instead, this change uses dlsym to load the
function if available.

Author: fabiomestre

source/adapters/level_zero/command_buffer.cpp

@@ -26,14 +26,9 @@ namespace {
 // given Context and Device.
 bool checkImmediateAppendSupport(ur_context_handle_t Context,
                                  ur_device_handle_t Device) {
-  // TODO The L0 driver is not reporting this extension yet. Once it does,
-  // switch to using the variable zeDriverImmediateCommandListAppendFound.
 
-  // Minimum version that supports zeCommandListImmediateAppendCommandListsExp.
-  constexpr uint32_t MinDriverVersion = 30898;
   bool DriverSupportsImmediateAppend =
-      Context->getPlatform()->isDriverVersionNewerOrSimilar(1, 3,
-                                                            MinDriverVersion);
+      Context->getPlatform()->ZeCommandListImmediateAppendExt.Supported;
 
   // If this environment variable is:
   //   - Set to 1: the immediate append path will always be enabled as long the
@@ -58,10 +53,8 @@ bool checkImmediateAppendSupport(ur_context_handle_t Context,
     if (EnableAppendPath && !DriverSupportsImmediateAppend) {
       logger::error("{} is set but "
                     "the current driver does not support the "
-                    "zeCommandListImmediateAppendCommandListsExp entrypoint. A "
-                    "driver version of at least {} is required to use the "
-                    "immediate append path.",
-                    AppendEnvVarName, MinDriverVersion);
+                    "zeCommandListImmediateAppendCommandListsExp entrypoint.",
+                    AppendEnvVarName);
       std::abort();
     }
 
@@ -1569,7 +1562,10 @@ ur_result_t enqueueImmediateAppendPath(
     ur_event_handle_t *Event, ur_command_list_ptr_t CommandListHelper,
     bool DoProfiling) {
 
+  ur_platform_handle_t Platform = CommandBuffer->Context->getPlatform();
+
   assert(CommandListHelper->second.IsImmediate);
+  assert(Platform->ZeCommandListImmediateAppendExt.Supported);
 
   _ur_ze_event_list_t UrZeEventList;
   if (NumEventsInWaitList) {
@@ -1587,7 +1583,8 @@ ur_result_t enqueueImmediateAppendPath(
         nullptr /*ForcedCmdQueue*/));
     assert(ZeCopyEngineImmediateListHelper->second.IsImmediate);
 
-    ZE2UR_CALL(zeCommandListImmediateAppendCommandListsExp,
+    ZE2UR_CALL(Platform->ZeCommandListImmediateAppendExt
+                   .zeCommandListImmediateAppendCommandListsExp,
                (ZeCopyEngineImmediateListHelper->first, 1,
                 &CommandBuffer->ZeCopyCommandList, nullptr,
                 UrZeEventList.Length, UrZeEventList.ZeEventList));
@@ -1599,7 +1596,8 @@ ur_result_t enqueueImmediateAppendPath(
   ze_event_handle_t &EventToSignal =
       DoProfiling ? CommandBuffer->ComputeFinishedEvent->ZeEvent
                   : (*Event)->ZeEvent;
-  ZE2UR_CALL(zeCommandListImmediateAppendCommandListsExp,
+  ZE2UR_CALL(Platform->ZeCommandListImmediateAppendExt
+                 .zeCommandListImmediateAppendCommandListsExp,
              (CommandListHelper->first, 1, &CommandBuffer->ZeComputeCommandList,
               EventToSignal, WaitList.Length, WaitList.ZeEventList));
 
@@ -1616,7 +1614,8 @@ ur_result_t enqueueImmediateAppendPath(
                (CommandListHelper->first,
                 CommandBuffer->ExecutionFinishedEvent->ZeEvent, 0, nullptr));
 
-    ZE2UR_CALL(zeCommandListImmediateAppendCommandListsExp,
+    ZE2UR_CALL(Platform->ZeCommandListImmediateAppendExt
+                   .zeCommandListImmediateAppendCommandListsExp,
                (CommandListHelper->first, 1,
                 &CommandBuffer->ZeCommandListResetEvents, nullptr, 0, nullptr));
   }

source/adapters/level_zero/platform.cpp

@@ -224,6 +224,7 @@ ur_result_t ur_platform_handle_t_::initialize() {
 
   bool MutableCommandListSpecExtensionSupported = false;
   bool ZeIntelExternalSemaphoreExtensionSupported = false;
+  bool ZeImmediateCommandListAppendExtensionFound = false;
   for (auto &extension : ZeExtensions) {
     // Check if global offset extension is available
     if (strncmp(extension.name, ZE_GLOBAL_OFFSET_EXP_NAME,
@@ -248,6 +249,7 @@ ur_result_t ur_platform_handle_t_::initialize() {
         ZeDriverEventPoolCountingEventsExtensionFound = true;
       }
     }
+
     // Check if extension is available for Mutable Command List v1.1.
     if (strncmp(extension.name, ZE_MUTABLE_COMMAND_LIST_EXP_NAME,
                 strlen(ZE_MUTABLE_COMMAND_LIST_EXP_NAME) + 1) == 0) {
@@ -427,6 +429,21 @@ ur_result_t ur_platform_handle_t_::initialize() {
                   &ZeMutableCmdListExt
                        .zexCommandListGetNextCommandIdWithKernelsExp))) == 0);
   }
+
+  // Check if ImmediateAppendCommandList is supported and initialize the
+  // function pointer.
+  if (ZeImmediateCommandListAppendExtensionFound) {
+    ZeCommandListImmediateAppendExt
+        .zeCommandListImmediateAppendCommandListsExp =
+        (ze_pfnCommandListImmediateAppendCommandListsExp_t)
+            ur_loader::LibLoader::getFunctionPtr(
+                GlobalAdapter->processHandle,
+                "zeCommandListImmediateAppendCommandListsExp");
+    ZeCommandListImmediateAppendExt.Supported =
+        ZeCommandListImmediateAppendExt
+            .zeCommandListImmediateAppendCommandListsExp != nullptr;
+  }
+
   return UR_RESULT_SUCCESS;
 }
 

source/adapters/level_zero/platform.hpp

@@ -134,4 +134,11 @@ struct ur_platform_handle_t_ : public _ur_platform {
     ze_result_t (*zexDeviceReleaseExternalSemaphoreExp)(
         ze_intel_external_semaphore_exp_handle_t);
   } ZeExternalSemaphoreExt;
-};
+
+  struct ZeCommandListImmediateAppendExtension {
+    bool Supported = false;
+    ze_result_t (*zeCommandListImmediateAppendCommandListsExp)(
+        ze_command_list_handle_t, uint32_t, ze_command_list_handle_t *,
+        ze_event_handle_t, uint32_t, ze_event_handle_t *);
+  } ZeCommandListImmediateAppendExt;
+};