1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
<!-- markdownlint-disable MD041 -->
<!-- Copyright 2015-2025 LunarG, Inc. -->
[![Khronos Vulkan][1]][2]
[1]: https://vulkan.lunarg.com/img/Vulkan_100px_Dec16.png "https://www.khronos.org/vulkan/"
[2]: https://www.khronos.org/vulkan/
# 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](./limitations.md) 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](https://vulkan.lunarg.com/doc/view/latest/windows/layer_configuration.html) documentation and described in the [Configuring Vulkan Layers](https://www.lunarg.com/wp-content/uploads/2024/04/Configuring-Vulkan-Layers-LunarG-Christophe-Riccio-04-11-2024.pdf) whitepaper.
## *Vulkan Configurator*
We suggest people to use [*Vulkan Configurator*](https://www.lunarg.com/introducing-the-new-vulkan-configurator-vkconfig/).
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!).
```c++
// 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](https://vulkan.lunarg.com/doc/view/latest/windows/layer_configuration.html) to describe this file, but the short answer is to set the `VK_LAYER_SETTINGS_PATH` like the following:
```bash
# 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](../layers/vk_layer_settings.txt) file you can start with.
## Environment Variables
This is done for us via the `vkuCreateLayerSettingSet` call in the [Vulkan-Utility-Libraries](https://github.com/KhronosGroup/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:
```bash
# Windows
set VK_LAYER_MESSAGE_ID_FILTER=VUID-VkInstanceCreateInfo-pNext-pNext
# Linux
export VK_LAYER_MESSAGE_ID_FILTER=VUID-VkInstanceCreateInfo-pNext-pNext
# Android
adb 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](https://vulkan.lunarg.com/doc/sdk/latest/windows/khronos_validation_layer.html).
|
