[L0] Enable Sysman Thru Env by default and have zesInit be optional

- Enable ZES_ENABLE_SYSMAN=1 by default unless
  UR_L0_ENABLE_SYSMAN_ENV_DEFAULT==0.
- Allows for Sysman support thru zeInit() without user input.
- Added UR_L0_ENABLE_ZESINIT_DEFAULT to allow for a customer to enable
  zesInit over sysman env init if the env allows it.
- NOTE: UR_L0_ENABLE_ZESINIT_DEFAULT=1 requires
  UR_L0_ENABLE_SYSMAN_ENV_DEFAULT==0 due to the env overwriting the
zesInit support.

Signed-off-by: Neil R. Spruit <[email protected]>

Author: nrspruit

source/adapters/level_zero/adapter.cpp

@@ -169,6 +169,14 @@ ur_adapter_handle_t_::ur_adapter_handle_t_()
       return;
     }
 
+    // Check if the user has disabled the default L0 Env initialization.
+    const int UrSysManEnvInitEnabled = [] {
+      const char *UrRet = std::getenv("UR_L0_ENABLE_SYSMAN_ENV_DEFAULT");
+      if (!UrRet)
+        return 1;
+      return std::atoi(UrRet);
+    }();
+
     // initialize level zero only once.
     if (GlobalAdapter->ZeResult == std::nullopt) {
       // Setting these environment variables before running zeInit will enable
@@ -196,6 +204,11 @@ ur_adapter_handle_t_::ur_adapter_handle_t_()
       if (UrL0InitAllDrivers) {
         L0InitFlags |= ZE_INIT_FLAG_VPU_ONLY;
       }
+
+      // Set ZES_ENABLE_SYSMAN by default if the user has not set it.
+      if (UrSysManEnvInitEnabled) {
+        setEnvVar("ZES_ENABLE_SYSMAN", "1");
+      }
       logger::debug("\nzeInit with flags value of {}\n",
                     static_cast<int>(L0InitFlags));
       GlobalAdapter->ZeResult = ZE_CALL_NOCHECK(zeInit, (L0InitFlags));
@@ -223,15 +236,29 @@ ur_adapter_handle_t_::ur_adapter_handle_t_()
 #else
     HMODULE processHandle = nullptr;
 #endif
-    GlobalAdapter->getDeviceByUUIdFunctionPtr =
-        (zes_pfnDriverGetDeviceByUuidExp_t)ur_loader::LibLoader::getFunctionPtr(
-            processHandle, "zesDriverGetDeviceByUuidExp");
-    GlobalAdapter->getSysManDriversFunctionPtr =
-        (zes_pfnDriverGet_t)ur_loader::LibLoader::getFunctionPtr(
-            processHandle, "zesDriverGet");
-    GlobalAdapter->sysManInitFunctionPtr =
-        (zes_pfnInit_t)ur_loader::LibLoader::getFunctionPtr(processHandle,
-                                                            "zesInit");
+
+    // Check if the user has enabled the default L0 SysMan initialization.
+    const int UrSysmanZesinitEnable = [] {
+      const char *UrRet = std::getenv("UR_L0_ENABLE_ZESINIT_DEFAULT");
+      if (!UrRet)
+        return 0;
+      return std::atoi(UrRet);
+    }();
+
+    // Enable zesInit by default only if ZES_ENABLE_SYSMAN has not been set by
+    // default and UrSysmanZesinitEnable is true.
+    if (UrSysmanZesinitEnable && !UrSysManEnvInitEnabled) {
+      GlobalAdapter->getDeviceByUUIdFunctionPtr =
+          (zes_pfnDriverGetDeviceByUuidExp_t)
+              ur_loader::LibLoader::getFunctionPtr(
+                  processHandle, "zesDriverGetDeviceByUuidExp");
+      GlobalAdapter->getSysManDriversFunctionPtr =
+          (zes_pfnDriverGet_t)ur_loader::LibLoader::getFunctionPtr(
+              processHandle, "zesDriverGet");
+      GlobalAdapter->sysManInitFunctionPtr =
+          (zes_pfnInit_t)ur_loader::LibLoader::getFunctionPtr(processHandle,
+                                                              "zesInit");
+    }
     if (GlobalAdapter->getDeviceByUUIdFunctionPtr &&
         GlobalAdapter->getSysManDriversFunctionPtr &&
         GlobalAdapter->sysManInitFunctionPtr) {