Skip to content


Switch branches/tags

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time


This repository provides a focus and tools to help application developers understand and provide input to the Vulkan Portability initiative, including the VK_KHR_portability_subset Vulkan extension.

VK_KHR_portability_subset Extension

The VK_KHR_portability_subset extension is now included in the Vulkan specification.

This extension allows a non-conformant Vulkan implementation to be built on top of another non-Vulkan graphics API, and identifies differences between that implementation and a fully-conformant native Vulkan implementation.

This extension provides Vulkan implementations with the ability to mark otherwise-required capabilities as unsupported, or to establish additional properties and limits that the application should adhere to in order to guarantee portable behaviour and operation across platforms, including platforms where Vulkan is not natively supported.

The goal of this specification is to document, and make queryable, capabilities which are required to be supported by a fully-conformant Vulkan 1.0 implementation, but may be optional for an implementation of the Vulkan 1.0 Portability Subset.

The intent is that this extension will be advertised only on implementations of the Vulkan 1.0 Portability Subset, and not on conformant implementations of Vulkan 1.0. Fully-conformant Vulkan implementations provide all the required capabilies, and so will not provide this extension. Therefore, the existence of this extension can be used to determine that an implementation is likely not fully conformant with the Vulkan spec.

If this extension is supported by the Vulkan implementation, the application must enable this extension.

This extension defines several new structures that can be chained to the existing structures used by certain standard Vulkan calls, in order to query for non-conformant portable behavior.

Provide Your Feedback!

The VK_KHR_portability_subset extension is provisional, which means it is being released to the developer community with the intention of collecting feedback for the final version. Help us evolve this provisional extension specification by providing feedback and suggestions, or submitting any issues you encounterto the Vulkan Portability issues list in this repository.