VK_LAYER_KHRONOS_validation
The VK_LAYER_KHRONOS_validation layer supports the following validation coverage areas:
- Core validation
- Stateless parameter validation
- Object lifetime validation
- GPU-Assisted validation
- Thread safety validation
- Synchronization validation
- Best practices validation
- Debug Printf functionality
- Handle wrapping functionality
Note:
Most Khronos Validation layer features can be used simultaneously. However, this could result in noticeable performance degradation. The best practice is to run Core validation, GPU-Assisted validation, Synchronization Validation and Best practices validation features individually.
Debug Printf functionality and GPU-Assisted validation cannot be run at the same time.
Layer Controls
Layer behavior is controlled through either a layer settings file or an extension. The layer settings file allows a user to control various layer features and behaviors by providing easily modifiable settings. The Vulkan Validation Features extension provides layer controls, while the Vulkan Debug Utils extension profides methods of accessing and controlling feedback from the layers:
| Extension | Description |
|---|---|
| VK_EXT_validation_features | allows application control of various layer features |
| VK_EXT_debug_utils | allows application control and capture of debug reporting information |
See the Layers Overview and Configuration document for more detailed information on configuring Vulkan layers.
VK_EXT_validation_features
The preferred method for an application to programmatically control validation layer features is through the VK_EXT_validation_features extension. Using this extension allows an application to enable or disable specific Khronos validation features. Note that this extension provides low-level control to an application, and that some combinations of enable/disable settings may produce undefined behavior.
The VK_EXT_validation_features flags can be used to disable validation corresponding to the following deprecated layers:
Setting this VK_EXT_validation_features disable flag | Corresponds to not loading this deprecated layer |
|---|---|
VK_VALIDATION_FEATURE_DISABLE_THREAD_SAFETY_EXT | VK_LAYER_GOOGLE_threading |
VK_VALIDATION_FEATURE_DISABLE_API_PARAMETERS_EXT | VK_LAYER_LUNARG_parameter_validation |
VK_VALIDATION_FEATURE_DISABLE_OBJECT_LIFETIMES_EXT | VK_LAYER_LUNARG_object_tracker |
VK_VALIDATION_FEATURE_DISABLE_CORE_CHECKS_EXT | VK_LAYER_LUNARG_core_validation |
VK_VALIDATION_FEATURE_DISABLE_UNIQUE_HANDLES_EXT | VK_LAYER_GOOGLE_unqiue_objects |
Refer to VK_EXT_validation_features in the Vulkan specification for details on this extension.
VK_EXT_debug_utils
The preferred method for an app to control layer logging is via the VK_EXT_debug_utils extension. Using the VK_EXT_debug_utils extension allows an application to register multiple messengers with the layers. Each messenger can trigger a message callback when a log message occurs. Some messenger callbacks may log the information to a file, others may cause a debug break point or other-application defined behavior. An application can create a messenger even when no layers are enabled, but they will only be called for loader and, if implemented, driver events. Each message is identified by both a severity level and a message type. Severity levels indicate the severity of the message that should be logged including: error, warning, etc. Message types indicate the specific type of message including: validation, performance, etc. Some layers return a unique message ID string per message as well. Using the severity, type, and message ID, an application can easily filter the messages received by their messenger callback.
When reporting an error, the KHRONOS validation layer returns relevant specification information and a link to that information in the official Vulkan specification. Layers included in a Vulkan SDK will link to a version of the Vulkan specification annotated with valid usage identifiers.
Message Types As Reported By VK_EXT_debug_utils flags:
| Type | Debug Utils Severity | Debug Utils Type |
|---|---|---|
| Error | VK_DEBUG_UTILS_MESSAGE_SEVERITY_ERROR_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_VALIDATION_BIT_EXT |
| Warn | VK_DEBUG_UTILS_MESSAGE_SEVERITY_WARNING_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_VALIDATION_BIT_EXT |
| Perf Warn | VK_DEBUG_UTILS_MESSAGE_SEVERITY_WARNING_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_PERFORMANCE_BIT_EXT |
| Info | VK_DEBUG_UTILS_MESSAGE_SEVERITY_INFO_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_GENERAL_BIT_EXT or VK_DEBUG_UTILS_MESSAGE_TYPE_VALIDATION_BIT_EXT |
Refer to VK_EXT_debug_utils in the Vulkan Specification for details on this feature.