The Level Zero Loader will expose some additional APIs beyond what is defined in the Level Zero spec. The purpose of these APIs will generally be to access and set various loader configuration components.
This document does not cover APIs specific to individual layers (ie. tracing) or APIs defined in the Level Zero spec.
Exposed Loader APIs will be defined in header files located in this repository at include/loader
, and installed to <prefix>/include/level_zero/loader
This API is used to retreive the version information of the loader itself and of any layers that are enabled.
- *num_elems Is a pointer to the number of version components to get.
- *versions Pointer to address to write version components to. If set to
nullptr
,num_elems
will be set to the total number of version components available.
There are currently 3 versioned components assigned the following name strings:
"tracing layer"
"validation layer"
"loader"
When a system has multiple L0 drivers, raw handles returned from the L0 drivers are modified by the loader before being returned to the application. This allows the loader to determine which handles belong to which driver and forward API calls appropriately. In most cases the loader will perform this handle translation completely transparently to the application and no manual translation is ever needed.
In some rare cases when the application needs to occasionally bypass the loader, handle conflicts can arise. One such case is when an application wants to call a driver extension function whose address has been retreived with zeDriverGetExtensionFunctionAddress
To solve this issue, zelLoaderTranslateHandle
is used to retrieve the raw driver handle associated with a loader handle.
- handleType Type of the L0 handle to translate
- *handleIn Input handle to translate
- **handleOut Output location to store the translated handle