VK_LAYER_KHRONOS_validation

Vulkan is an Explicit API, enabling direct control over how GPUs actually work. By design, minimal error checking is done inside a Vulkan driver - applications have full control and responsibility for correct operation. Any errors in Vulkan usage can result in unexpected behavior or even a crash. The VK_LAYER_KHRONOS_validation layer can be used to to assist developers in isolating incorrect usage, and in verifying that applications correctly use the API.

It is important to acknowledge there are a few limitations for what the Validation Layers can do.

Configuring the Validation Layer

There are 4 ways to configure the settings: Vulkan Configurator, application defined, vk_layer_settings.txt, environment variables as described in the layers configuration documentation and described in the Configuring Vulkan Layers whitepaper.

Vulkan Configurator

We suggest people to use Vulkan Configurator.

The GUI comes with the SDK, and takes the VkLayer_khronos_validation.json file and does everything for you!

Application Defined

The application can now use the VK_EXT_layer_settings extension to do everything at vkCreateInstance time. (Don't worry, we implement the extension, so it will be supported 100% of the time!).

// Example how to turn on verbose mode for DebugPrintf
const VkBool32 verbose_value = true;
const VkLayerSettingEXT layer_setting = {"VK_LAYER_KHRONOS_validation", "printf_verbose", VK_LAYER_SETTING_TYPE_BOOL32_EXT, 1, &verbose_value};
VkLayerSettingsCreateInfoEXT layer_settings_create_info = {VK_STRUCTURE_TYPE_LAYER_SETTINGS_CREATE_INFO_EXT, nullptr, 1, &layer_setting};

VkInstanceCreateInfo instance_ci = GetYourCreateInfo();
instance_ci.pNext = &layer_settings_create_info;

vk_layer_settings.txt

There is info elsewhere to describe this file, but the short answer is to set the VK_LAYER_SETTINGS_PATH like the following:

# windows
set VK_LAYER_SETTINGS_PATH=C:\path\to\vk_layer_settings.txt

# linux
export VK_LAYER_SETTINGS_PATH=/path/to/vk_layer_settings.txt

and it will set things for you in that file. We have a default example file you can start with.

Environment Variables

This is done for us via the vkuCreateLayerSettingSet call in the Vulkan-Utility-Libraries.

As an example, in our VkLayer_khronos_validation.json file you will find something like "key": "message_id_filter",.

From here you just need to adjust it the naming and prefix depending on your platform:

# Windows
set VK_LAYER_MESSAGE_ID_FILTER=VUID-VkInstanceCreateInfo-pNext-pNext

# Linux
export VK_LAYER_MESSAGE_ID_FILTER=VUID-VkInstanceCreateInfo-pNext-pNext

# Android
adb shell setprop debug.vulkan.khronos_validation.message_id_filter=VUID-VkInstanceCreateInfo-pNext-pNext

Layer Settings

We suggest using Vulkan Configurator to discover the layer settings, but the following is generated per SDK version

The settings for this layer are specified in VkLayer_khronos_validation.json. The settings details are in khronos_validation_layer.html.