## C Specification

The VkPhysicalDeviceIDProperties structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkPhysicalDeviceIDProperties {
VkStructureType    sType;
void*              pNext;
uint8_t            deviceUUID[VK_UUID_SIZE];
uint8_t            driverUUID[VK_UUID_SIZE];
uint8_t            deviceLUID[VK_LUID_SIZE];
VkBool32           deviceLUIDValid;
} VkPhysicalDeviceIDProperties;

or the equivalent

// Provided by VK_KHR_external_fence_capabilities, VK_KHR_external_memory_capabilities, VK_KHR_external_semaphore_capabilities
typedef VkPhysicalDeviceIDProperties VkPhysicalDeviceIDPropertiesKHR;

## Members

• sType is the type of this structure.

• pNext is NULL or a pointer to a structure extending this structure.

## Description

• deviceUUID is an array of VK_UUID_SIZE uint8_t values representing a universally unique identifier for the device.

• driverUUID is an array of VK_UUID_SIZE uint8_t values representing a universally unique identifier for the driver build in use by the device.

• deviceLUID is an array of VK_LUID_SIZE uint8_t values representing a locally unique identifier for the device.

• deviceNodeMask is a uint32_t bitfield identifying the node within a linked device adapter corresponding to the device.

• deviceLUIDValid is a boolean value that will be VK_TRUE if deviceLUID contains a valid LUID and deviceNodeMask contains a valid node mask, and VK_FALSE if they do not.

If the VkPhysicalDeviceIDProperties structure is included in the pNext chain of the VkPhysicalDeviceProperties2 structure passed to vkGetPhysicalDeviceProperties2, it is filled in with each corresponding implementation-dependent property.

deviceUUID must be immutable for a given device across instances, processes, driver APIs, driver versions, and system reboots.

Applications can compare the driverUUID value across instance and process boundaries, and can make similar queries in external APIs to determine whether they are capable of sharing memory objects and resources using them with the device.

deviceUUID and/or driverUUID must be used to determine whether a particular external object can be shared between driver components, where such a restriction exists as defined in the compatibility table for the particular object type:

If deviceLUIDValid is VK_FALSE, the values of deviceLUID and deviceNodeMask are undefined. If deviceLUIDValid is VK_TRUE and Vulkan is running on the Windows operating system, the contents of deviceLUID can be cast to an LUID object and must be equal to the locally unique identifier of a IDXGIAdapter1 object that corresponds to physicalDevice. If deviceLUIDValid is VK_TRUE, deviceNodeMask must contain exactly one bit. If Vulkan is running on an operating system that supports the Direct3D 12 API and physicalDevice corresponds to an individual device in a linked device adapter, deviceNodeMask identifies the Direct3D 12 node corresponding to physicalDevice. Otherwise, deviceNodeMask must be 1.

 Note Although they have identical descriptions, VkPhysicalDeviceIDProperties::deviceUUID may differ from VkPhysicalDeviceProperties2::pipelineCacheUUID. The former is intended to identify and correlate devices across API and driver boundaries, while the latter is used to identify a compatible device and driver combination to use when serializing and de-serializing pipeline state. Implementations should return deviceUUID values which are likely to be unique even in the presence of multiple Vulkan implementations (such as a GPU driver and a software renderer; two drivers for different GPUs; or the same Vulkan driver running on two logically different devices). Khronos' conformance testing is unable to guarantee that deviceUUID values are actually unique, so implementors should make their own best efforts to ensure this. In particular, hard-coded deviceUUID values, especially all-0 bits, should never be used. A combination of values unique to the vendor, the driver, and the hardware environment can be used to provide a deviceUUID which is unique to a high degree of certainty. Some possible inputs to such a computation are: Information reported by vkGetPhysicalDeviceProperties PCI device ID (if defined) PCI bus ID, or similar system configuration information. Driver binary checksums.
 Note While VkPhysicalDeviceIDProperties::deviceUUID is specified to remain consistent across driver versions and system reboots, it is not intended to be usable as a serializable persistent identifier for a device. It may change when a device is physically added to, removed from, or moved to a different connector in a system while that system is powered down. Further, there is no reasonable way to verify with conformance testing that a given device retains the same UUID in a given system across all driver versions supported in that system. While implementations should make every effort to report consistent device UUIDs across driver versions, applications should avoid relying on the persistence of this value for uses other than identifying compatible devices for external object sharing purposes.
Valid Usage (Implicit)
• VUID-VkPhysicalDeviceIDProperties-sType-sType
sType must be VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ID_PROPERTIES

VK_VERSION_1_1, VkBool32, VkStructureType