Author: The Khronos® Vulkan Working Group

# Vulkan® 1.3.227 - A Specification (with all registered extensions)

The Khronos® Vulkan Working Group
version 1.3.227, 2022-09-08 16:48:57Z
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## 11. Memory Allocation

Vulkan memory is broken up into two categories, host memory and device memory.

### 11.1. Host Memory

Host memory is memory needed by the Vulkan implementation for non-device-visible storage.

| Note This memory may be used to store the implementation’s representation and state of Vulkan objects.

Vulkan provides applications the opportunity to perform host memory allocations on behalf of the Vulkan implementation. If this feature is not used, the implementation will perform its own memory allocations. Since most memory allocations are off the critical path, this is not meant as a performance feature. Rather, this can be useful for certain embedded systems, for debugging purposes (e.g. putting a guard page after all host allocations), or for memory allocation logging.

Allocators are provided by the application as a pointer to a `VkAllocationCallbacks` structure:

    // Provided by VK_VERSION_1_0
    typedef struct VkAllocationCallbacks {
        void*                                   pUserData;
        PFN_vkAllocationFunction                pfnAllocation;
        PFN_vkReallocationFunction              pfnReallocation;
        PFN_vkFreeFunction                      pfnFree;
        PFN_vkInternalAllocationNotification    pfnInternalAllocation;
        PFN_vkInternalFreeNotification          pfnInternalFree;
    } VkAllocationCallbacks;

- `pUserData` is a value to be interpreted by the implementation of the callbacks. When any of the callbacks in `VkAllocationCallbacks` are called, the Vulkan implementation will pass this value as the first parameter to the callback. This value can vary each time an allocator is passed into a command, even when the same object takes an allocator in multiple commands.

- `pfnAllocation` is a PFN_vkAllocationFunction pointer to an application-defined memory allocation function.

- `pfnReallocation` is a PFN_vkReallocationFunction pointer to an application-defined memory reallocation function.

- `pfnFree` is a PFN_vkFreeFunction pointer to an application-defined memory free function.

- `pfnInternalAllocation` is a PFN_vkInternalAllocationNotification pointer to an application-defined function that is called by the implementation when the implementation makes internal allocations.

- `pfnInternalFree` is a PFN_vkInternalFreeNotification pointer to an application-defined function that is called by the implementation when the implementation frees internal allocations.

Valid Usage

- VUID-VkAllocationCallbacks-pfnAllocation-00632
  `pfnAllocation` must be a valid pointer to a valid user-defined PFN_vkAllocationFunction

- VUID-VkAllocationCallbacks-pfnReallocation-00633
  `pfnReallocation` must be a valid pointer to a valid user-defined PFN_vkReallocationFunction

- VUID-VkAllocationCallbacks-pfnFree-00634
  `pfnFree` must be a valid pointer to a valid user-defined PFN_vkFreeFunction

- VUID-VkAllocationCallbacks-pfnInternalAllocation-00635
  If either of `pfnInternalAllocation` or `pfnInternalFree` is not `NULL`, both must be valid callbacks

The type of `pfnAllocation` is:

    // Provided by VK_VERSION_1_0
    typedef void* (VKAPI_PTR *PFN_vkAllocationFunction)(
        void*                                       pUserData,
        size_t                                      size,
        size_t                                      alignment,
        VkSystemAllocationScope                     allocationScope);

- `pUserData` is the value specified for VkAllocationCallbacks::`pUserData` in the allocator specified by the application.

- `size` is the size in bytes of the requested allocation.

- `alignment` is the requested alignment of the allocation in bytes and must be a power of two.

- `allocationScope` is a VkSystemAllocationScope value specifying the allocation scope of the lifetime of the allocation, as described here.

If `pfnAllocation` is unable to allocate the requested memory, it must return `NULL`. If the allocation was successful, it must return a valid pointer to memory allocation containing at least `size` bytes, and with the pointer value being a multiple of `alignment`.

| Note Correct Vulkan operation cannot be assumed if the application does not follow these rules. For example, `pfnAllocation` (or `pfnReallocation`) could cause termination of running Vulkan instance(s) on a failed allocation for debugging purposes, either directly or indirectly. In these circumstances, it cannot be assumed that any part of any affected VkInstance objects are going to operate correctly (even vkDestroyInstance), and the application must ensure it cleans up properly via other means (e.g. process termination).

If `pfnAllocation` returns `NULL`, and if the implementation is unable to continue correct processing of the current command without the requested allocation, it must treat this as a runtime error, and generate `VK_ERROR_OUT_OF_HOST_MEMORY` at the appropriate time for the command in which the condition was detected, as described in Return Codes.

If the implementation is able to continue correct processing of the current command without the requested allocation, then it may do so, and must not generate `VK_ERROR_OUT_OF_HOST_MEMORY` as a result of this failed allocation.

The type of `pfnReallocation` is:

    // Provided by VK_VERSION_1_0
    typedef void* (VKAPI_PTR *PFN_vkReallocationFunction)(
        void*                                       pUserData,
        void*                                       pOriginal,
        size_t                                      size,
        size_t                                      alignment,
        VkSystemAllocationScope                     allocationScope);

- `pUserData` is the value specified for VkAllocationCallbacks::`pUserData` in the allocator specified by the application.

- `pOriginal` must be either `NULL` or a pointer previously returned by `pfnReallocation` or `pfnAllocation` of a compatible allocator.

- `size` is the size in bytes of the requested allocation.

- `alignment` is the requested alignment of the allocation in bytes and must be a power of two.

- `allocationScope` is a VkSystemAllocationScope value specifying the allocation scope of the lifetime of the allocation, as described here.

`pfnReallocation` must return an allocation with enough space for `size` bytes, and the contents of the original allocation from bytes zero to min(original size, new size) - 1 must be preserved in the returned allocation. If `size` is larger than the old size, the contents of the additional space are undefined. If satisfying these requirements involves creating a new allocation, then the old allocation should be freed.

If `pOriginal` is `NULL`, then `pfnReallocation` must behave equivalently to a call to PFN_vkAllocationFunction with the same parameter values (without `pOriginal`).

If `size` is zero, then `pfnReallocation` must behave equivalently to a call to PFN_vkFreeFunction with the same `pUserData` parameter value, and `pMemory` equal to `pOriginal`.

If `pOriginal` is non-`NULL`, the implementation must ensure that `alignment` is equal to the `alignment` used to originally allocate `pOriginal`.

If this function fails and `pOriginal` is non-`NULL` the application must not free the old allocation.

`pfnReallocation` must follow the same rules for return values as `PFN_vkAllocationFunction`.

The type of `pfnFree` is:

    // Provided by VK_VERSION_1_0
    typedef void (VKAPI_PTR *PFN_vkFreeFunction)(
        void*                                       pUserData,
        void*                                       pMemory);

- `pUserData` is the value specified for VkAllocationCallbacks::`pUserData` in the allocator specified by the application.

- `pMemory` is the allocation to be freed.

`pMemory` may be `NULL`, which the callback must handle safely. If `pMemory` is non-`NULL`, it must be a pointer previously allocated by `pfnAllocation` or `pfnReallocation`. The application should free this memory.

The type of `pfnInternalAllocation` is:

    // Provided by VK_VERSION_1_0
    typedef void (VKAPI_PTR *PFN_vkInternalAllocationNotification)(
        void*                                       pUserData,
        size_t                                      size,
        VkInternalAllocationType                    allocationType,
        VkSystemAllocationScope                     allocationScope);

- `pUserData` is the value specified for VkAllocationCallbacks::`pUserData` in the allocator specified by the application.

- `size` is the requested size of an allocation.

- `allocationType` is a VkInternalAllocationType value specifying the requested type of an allocation.

- `allocationScope` is a VkSystemAllocationScope value specifying the allocation scope of the lifetime of the allocation, as described here.

This is a purely informational callback.

The type of `pfnInternalFree` is:

    // Provided by VK_VERSION_1_0
    typedef void (VKAPI_PTR *PFN_vkInternalFreeNotification)(
        void*                                       pUserData,
        size_t                                      size,
        VkInternalAllocationType                    allocationType,
        VkSystemAllocationScope                     allocationScope);

- `pUserData` is the value specified for VkAllocationCallbacks::`pUserData` in the allocator specified by the application.

- `size` is the requested size of an allocation.

- `allocationType` is a VkInternalAllocationType value specifying the requested type of an allocation.

- `allocationScope` is a VkSystemAllocationScope value specifying the allocation scope of the lifetime of the allocation, as described here.

Each allocation has an allocation scope defining its lifetime and which object it is associated with. Possible values passed to the `allocationScope` parameter of the callback functions specified by VkAllocationCallbacks, indicating the allocation scope, are:

    // Provided by VK_VERSION_1_0
    typedef enum VkSystemAllocationScope {
        VK_SYSTEM_ALLOCATION_SCOPE_COMMAND = 0,
        VK_SYSTEM_ALLOCATION_SCOPE_OBJECT = 1,
        VK_SYSTEM_ALLOCATION_SCOPE_CACHE = 2,
        VK_SYSTEM_ALLOCATION_SCOPE_DEVICE = 3,
        VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE = 4,
    } VkSystemAllocationScope;

- `VK_SYSTEM_ALLOCATION_SCOPE_COMMAND` specifies that the allocation is scoped to the duration of the Vulkan command.

- `VK_SYSTEM_ALLOCATION_SCOPE_OBJECT` specifies that the allocation is scoped to the lifetime of the Vulkan object that is being created or used.

- `VK_SYSTEM_ALLOCATION_SCOPE_CACHE` specifies that the allocation is scoped to the lifetime of a `VkPipelineCache` or `VkValidationCacheEXT` object.

- `VK_SYSTEM_ALLOCATION_SCOPE_DEVICE` specifies that the allocation is scoped to the lifetime of the Vulkan device.

- `VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE` specifies that the allocation is scoped to the lifetime of the Vulkan instance.

Most Vulkan commands operate on a single object, or there is a sole object that is being created or manipulated. When an allocation uses an allocation scope of `VK_SYSTEM_ALLOCATION_SCOPE_OBJECT` or `VK_SYSTEM_ALLOCATION_SCOPE_CACHE`, the allocation is scoped to the object being created or manipulated.

When an implementation requires host memory, it will make callbacks to the application using the most specific allocator and allocation scope available:

- If an allocation is scoped to the duration of a command, the allocator will use the `VK_SYSTEM_ALLOCATION_SCOPE_COMMAND` allocation scope. The most specific allocator available is used: if the object being created or manipulated has an allocator, that object’s allocator will be used, else if the parent `VkDevice` has an allocator it will be used, else if the parent `VkInstance` has an allocator it will be used. Else,

- If an allocation is associated with a `VkValidationCacheEXT` or `VkPipelineCache` object, the allocator will use the `VK_SYSTEM_ALLOCATION_SCOPE_CACHE` allocation scope. The most specific allocator available is used (cache, else device, else instance). Else,

- If an allocation is scoped to the lifetime of an object, that object is being created or manipulated by the command, and that object’s type is not `VkDevice` or `VkInstance`, the allocator will use an allocation scope of `VK_SYSTEM_ALLOCATION_SCOPE_OBJECT`. The most specific allocator available is used (object, else device, else instance). Else,

- If an allocation is scoped to the lifetime of a device, the allocator will use an allocation scope of `VK_SYSTEM_ALLOCATION_SCOPE_DEVICE`. The most specific allocator available is used (device, else instance). Else,

- If the allocation is scoped to the lifetime of an instance and the instance has an allocator, its allocator will be used with an allocation scope of `VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE`.

- Otherwise an implementation will allocate memory through an alternative mechanism that is unspecified.

Objects that are allocated from pools do not specify their own allocator. When an implementation requires host memory for such an object, that memory is sourced from the object’s parent pool’s allocator.

The application is not expected to handle allocating memory that is intended for execution by the host due to the complexities of differing security implementations across multiple platforms. The implementation will allocate such memory internally and invoke an application provided informational callback when these internal allocations are allocated and freed. Upon allocation of executable memory, `pfnInternalAllocation` will be called. Upon freeing executable memory, `pfnInternalFree` will be called. An implementation will only call an informational callback for executable memory allocations and frees.

The `allocationType` parameter to the `pfnInternalAllocation` and `pfnInternalFree` functions may be one of the following values:

    // Provided by VK_VERSION_1_0
    typedef enum VkInternalAllocationType {
        VK_INTERNAL_ALLOCATION_TYPE_EXECUTABLE = 0,
    } VkInternalAllocationType;

- `VK_INTERNAL_ALLOCATION_TYPE_EXECUTABLE` specifies that the allocation is intended for execution by the host.

An implementation must only make calls into an application-provided allocator during the execution of an API command. An implementation must only make calls into an application-provided allocator from the same thread that called the provoking API command. The implementation should not synchronize calls to any of the callbacks. If synchronization is needed, the callbacks must provide it themselves. The informational callbacks are subject to the same restrictions as the allocation callbacks.

If an implementation intends to make calls through a `VkAllocationCallbacks` structure between the time a `vkCreate*` command returns and the time a corresponding `vkDestroy*` command begins, that implementation must save a copy of the allocator before the `vkCreate*` command returns. The callback functions and any data structures they rely upon must remain valid for the lifetime of the object they are associated with.

If an allocator is provided to a `vkCreate*` command, a compatible allocator must be provided to the corresponding `vkDestroy*` command. Two `VkAllocationCallbacks` structures are compatible if memory allocated with `pfnAllocation` or `pfnReallocation` in each can be freed with `pfnReallocation` or `pfnFree` in the other. An allocator must not be provided to a `vkDestroy*` command if an allocator was not provided to the corresponding `vkCreate*` command.

If a non-`NULL` allocator is used, the `pfnAllocation`, `pfnReallocation` and `pfnFree` members must be non-`NULL` and point to valid implementations of the callbacks. An application can choose to not provide informational callbacks by setting both `pfnInternalAllocation` and `pfnInternalFree` to `NULL`. `pfnInternalAllocation` and `pfnInternalFree` must either both be `NULL` or both be non-`NULL`.

If `pfnAllocation` or `pfnReallocation` fail, the implementation may fail object creation and/or generate a `VK_ERROR_OUT_OF_HOST_MEMORY` error, as appropriate.

Allocation callbacks must not call any Vulkan commands.

The following sets of rules define when an implementation is permitted to call the allocator callbacks.

`pfnAllocation` or `pfnReallocation` may be called in the following situations:

- Allocations scoped to a `VkDevice` or `VkInstance` may be allocated from any API command.

- Allocations scoped to a command may be allocated from any API command.

- Allocations scoped to a `VkPipelineCache` may only be allocated from:

  - `vkCreatePipelineCache`

  - `vkMergePipelineCaches` for `dstCache`

  - `vkCreateGraphicsPipelines` for `pipelineCache`

  - `vkCreateComputePipelines` for `pipelineCache`

- Allocations scoped to a `VkValidationCacheEXT` may only be allocated from:

  - `vkCreateValidationCacheEXT`

  - `vkMergeValidationCachesEXT` for `dstCache`

  - `vkCreateShaderModule` for `validationCache` in VkShaderModuleValidationCacheCreateInfoEXT

- Allocations scoped to a `VkDescriptorPool` may only be allocated from:

  - any command that takes the pool as a direct argument

  - `vkAllocateDescriptorSets` for the `descriptorPool` member of its `pAllocateInfo` parameter

  - `vkCreateDescriptorPool`

- Allocations scoped to a `VkCommandPool` may only be allocated from:

  - any command that takes the pool as a direct argument

  - `vkCreateCommandPool`

  - `vkAllocateCommandBuffers` for the `commandPool` member of its `pAllocateInfo` parameter

  - any `vkCmd*` command whose `commandBuffer` was allocated from that `VkCommandPool`

- Allocations scoped to any other object may only be allocated in that object’s `vkCreate*` command.

`pfnFree`, or `pfnReallocation` with zero `size`, may be called in the following situations:

- Allocations scoped to a `VkDevice` or `VkInstance` may be freed from any API command.

- Allocations scoped to a command must be freed by any API command which allocates such memory.

- Allocations scoped to a `VkPipelineCache` may be freed from `vkDestroyPipelineCache`.

- Allocations scoped to a `VkValidationCacheEXT` may be freed from `vkDestroyValidationCacheEXT`.

- Allocations scoped to a `VkDescriptorPool` may be freed from

  - any command that takes the pool as a direct argument

- Allocations scoped to a `VkCommandPool` may be freed from:

  - any command that takes the pool as a direct argument

  - `vkResetCommandBuffer` whose `commandBuffer` was allocated from that `VkCommandPool`

- Allocations scoped to any other object may be freed in that object’s `vkDestroy*` command.

- Any command that allocates host memory may also free host memory of the same scope.

### 11.2. Device Memory

Device memory is memory that is visible to the device — for example the contents of the image or buffer objects, which can be natively used by the device.

#### 11.2.1. Device Memory Properties

Memory properties of a physical device describe the memory heaps and memory types available.

To query memory properties, call:

    // Provided by VK_VERSION_1_0
    void vkGetPhysicalDeviceMemoryProperties(
        VkPhysicalDevice                            physicalDevice,
        VkPhysicalDeviceMemoryProperties*           pMemoryProperties);

- `physicalDevice` is the handle to the device to query.

- `pMemoryProperties` is a pointer to a VkPhysicalDeviceMemoryProperties structure in which the properties are returned.

Valid Usage (Implicit)

- VUID-vkGetPhysicalDeviceMemoryProperties-physicalDevice-parameter
  `physicalDevice` must be a valid VkPhysicalDevice handle

- VUID-vkGetPhysicalDeviceMemoryProperties-pMemoryProperties-parameter
  `pMemoryProperties` must be a valid pointer to a VkPhysicalDeviceMemoryProperties structure

The `VkPhysicalDeviceMemoryProperties` structure is defined as:

    // Provided by VK_VERSION_1_0
    typedef struct VkPhysicalDeviceMemoryProperties {
        uint32_t        memoryTypeCount;
        VkMemoryType    memoryTypes[VK_MAX_MEMORY_TYPES];
        uint32_t        memoryHeapCount;
        VkMemoryHeap    memoryHeaps[VK_MAX_MEMORY_HEAPS];
    } VkPhysicalDeviceMemoryProperties;

- `memoryTypeCount` is the number of valid elements in the `memoryTypes` array.

- `memoryTypes` is an array of `VK_MAX_MEMORY_TYPES` VkMemoryType structures describing the memory types that can be used to access memory allocated from the heaps specified by `memoryHeaps`.

- `memoryHeapCount` is the number of valid elements in the `memoryHeaps` array.

- `memoryHeaps` is an array of `VK_MAX_MEMORY_HEAPS` VkMemoryHeap structures describing the memory heaps from which memory can be allocated.

The `VkPhysicalDeviceMemoryProperties` structure describes a number of memory heaps as well as a number of memory types that can be used to access memory allocated in those heaps. Each heap describes a memory resource of a particular size, and each memory type describes a set of memory properties (e.g. host cached vs uncached) that can be used with a given memory heap. Allocations using a particular memory type will consume resources from the heap indicated by that memory type’s heap index. More than one memory type may share each heap, and the heaps and memory types provide a mechanism to advertise an accurate size of the physical memory resources while allowing the memory to be used with a variety of different properties.

The number of memory heaps is given by `memoryHeapCount` and is less than or equal to `VK_MAX_MEMORY_HEAPS`. Each heap is described by an element of the `memoryHeaps` array as a VkMemoryHeap structure. The number of memory types available across all memory heaps is given by `memoryTypeCount` and is less than or equal to `VK_MAX_MEMORY_TYPES`. Each memory type is described by an element of the `memoryTypes` array as a VkMemoryType structure.

At least one heap must include `VK_MEMORY_HEAP_DEVICE_LOCAL_BIT` in VkMemoryHeap::`flags`. If there are multiple heaps that all have similar performance characteristics, they may all include `VK_MEMORY_HEAP_DEVICE_LOCAL_BIT`. In a unified memory architecture (UMA) system there is often only a single memory heap which is considered to be equally “local” to the host and to the device, and such an implementation must advertise the heap as device-local.

Each memory type returned by vkGetPhysicalDeviceMemoryProperties must have its `propertyFlags` set to one of the following values:

- 0

- `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT`

- `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_CACHED_BIT`

- `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_CACHED_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_CACHED_BIT`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_CACHED_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT`

- `VK_MEMORY_PROPERTY_PROTECTED_BIT`

- `VK_MEMORY_PROPERTY_PROTECTED_BIT` | `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT`

- `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` |
  `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD`

- `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_CACHED_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` |
  `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` |
  `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_CACHED_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` |
  `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD`

- `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` |
  `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD` |
  `VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD`

- `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_CACHED_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` |
  `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD` |
  `VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD` |
  `VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` |
  `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD` |
  `VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` |
  `VK_MEMORY_PROPERTY_HOST_CACHED_BIT` |
  `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` |
  `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD` |
  `VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD`

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` |
  `VK_MEMORY_PROPERTY_RDMA_CAPABLE_BIT_NV`

There must be at least one memory type with both the `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` and `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` bits set in its `propertyFlags`. There must be at least one memory type with the `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` bit set in its `propertyFlags`. If the `deviceCoherentMemory` feature is enabled, there must be at least one memory type with the `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD` bit set in its `propertyFlags`.

For each pair of elements X and Y returned in `memoryTypes`, X must be placed at a lower index position than Y if:

- the set of bit flags returned in the `propertyFlags` member of X is a strict subset of the set of bit flags returned in the `propertyFlags` member of Y; or

- the `propertyFlags` members of X and Y are equal, and X belongs to a memory heap with greater performance (as determined in an implementation-specific manner) ; or

- the `propertyFlags` members of Y includes `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD` or `VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD` and X does not

| Note There is no ordering requirement between X and Y elements for the case their `propertyFlags` members are not in a subset relation. That potentially allows more than one possible way to order the same set of memory types. Notice that the list of all allowed memory property flag combinations is written in a valid order. But if instead `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` was before `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` | `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT`, the list would still be in a valid order. There may be a performance penalty for using device coherent or uncached device memory types, and using these accidentally is undesirable. In order to avoid this, memory types with these properties always appear at the end of the list; but are subject to the same rules otherwise.

This ordering requirement enables applications to use a simple search loop to select the desired memory type along the lines of:

    // Find a memory in `memoryTypeBitsRequirement` that includes all of `requiredProperties`
    int32_t findProperties(const VkPhysicalDeviceMemoryProperties* pMemoryProperties,
                           uint32_t memoryTypeBitsRequirement,
                           VkMemoryPropertyFlags requiredProperties) {
        const uint32_t memoryCount = pMemoryProperties->memoryTypeCount;
        for (uint32_t memoryIndex = 0; memoryIndex < memoryCount; ++memoryIndex) {
            const uint32_t memoryTypeBits = (1 << memoryIndex);
            const bool isRequiredMemoryType = memoryTypeBitsRequirement & memoryTypeBits;

            const VkMemoryPropertyFlags properties =
                pMemoryProperties->memoryTypes[memoryIndex].propertyFlags;
            const bool hasRequiredProperties =
                (properties & requiredProperties) == requiredProperties;

            if (isRequiredMemoryType && hasRequiredProperties)
                return static_cast<int32_t>(memoryIndex);
        }

        // failed to find memory type
        return -1;
    }

    // Try to find an optimal memory type, or if it does not exist try fallback memory type
    // `device` is the VkDevice
    // `image` is the VkImage that requires memory to be bound
    // `memoryProperties` properties as returned by vkGetPhysicalDeviceMemoryProperties
    // `requiredProperties` are the property flags that must be present
    // `optimalProperties` are the property flags that are preferred by the application
    VkMemoryRequirements memoryRequirements;
    vkGetImageMemoryRequirements(device, image, &memoryRequirements);
    int32_t memoryType =
        findProperties(&memoryProperties, memoryRequirements.memoryTypeBits, optimalProperties);
    if (memoryType == -1) // not found; try fallback properties
        memoryType =
            findProperties(&memoryProperties, memoryRequirements.memoryTypeBits, requiredProperties);

`VK_MAX_MEMORY_TYPES` is the length of an array of VkMemoryType structures describing memory types, as returned in VkPhysicalDeviceMemoryProperties::memoryTypes.

    #define VK_MAX_MEMORY_TYPES               32U

`VK_MAX_MEMORY_HEAPS` is the length of an array of VkMemoryHeap structures describing memory heaps, as returned in VkPhysicalDeviceMemoryProperties::memoryHeaps.

    #define VK_MAX_MEMORY_HEAPS               16U

To query memory properties, call:

    // Provided by VK_VERSION_1_1
    void vkGetPhysicalDeviceMemoryProperties2(
        VkPhysicalDevice                            physicalDevice,
        VkPhysicalDeviceMemoryProperties2*          pMemoryProperties);

or the equivalent command

    // Provided by VK_KHR_get_physical_device_properties2
    void vkGetPhysicalDeviceMemoryProperties2KHR(
        VkPhysicalDevice                            physicalDevice,
        VkPhysicalDeviceMemoryProperties2*          pMemoryProperties);

- `physicalDevice` is the handle to the device to query.

- `pMemoryProperties` is a pointer to a VkPhysicalDeviceMemoryProperties2 structure in which the properties are returned.

`vkGetPhysicalDeviceMemoryProperties2` behaves similarly to vkGetPhysicalDeviceMemoryProperties, with the ability to return extended information in a `pNext` chain of output structures.

Valid Usage (Implicit)

- VUID-vkGetPhysicalDeviceMemoryProperties2-physicalDevice-parameter
  `physicalDevice` must be a valid VkPhysicalDevice handle

- VUID-vkGetPhysicalDeviceMemoryProperties2-pMemoryProperties-parameter
  `pMemoryProperties` must be a valid pointer to a VkPhysicalDeviceMemoryProperties2 structure

The `VkPhysicalDeviceMemoryProperties2` structure is defined as:

    // Provided by VK_VERSION_1_1
    typedef struct VkPhysicalDeviceMemoryProperties2 {
        VkStructureType                     sType;
        void*                               pNext;
        VkPhysicalDeviceMemoryProperties    memoryProperties;
    } VkPhysicalDeviceMemoryProperties2;

or the equivalent

    // Provided by VK_KHR_get_physical_device_properties2
    typedef VkPhysicalDeviceMemoryProperties2 VkPhysicalDeviceMemoryProperties2KHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memoryProperties` is a VkPhysicalDeviceMemoryProperties structure which is populated with the same values as in vkGetPhysicalDeviceMemoryProperties.

Valid Usage (Implicit)

- VUID-VkPhysicalDeviceMemoryProperties2-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MEMORY_PROPERTIES_2`

- VUID-VkPhysicalDeviceMemoryProperties2-pNext-pNext
  `pNext` must be `NULL` or a pointer to a valid instance of VkPhysicalDeviceMemoryBudgetPropertiesEXT

- VUID-VkPhysicalDeviceMemoryProperties2-sType-unique
  The `sType` value of each struct in the `pNext` chain must be unique

The `VkMemoryHeap` structure is defined as:

    // Provided by VK_VERSION_1_0
    typedef struct VkMemoryHeap {
        VkDeviceSize         size;
        VkMemoryHeapFlags    flags;
    } VkMemoryHeap;

- `size` is the total memory size in bytes in the heap.

- `flags` is a bitmask of VkMemoryHeapFlagBits specifying attribute flags for the heap.

Bits which may be set in VkMemoryHeap::`flags`, indicating attribute flags for the heap, are:

    // Provided by VK_VERSION_1_0
    typedef enum VkMemoryHeapFlagBits {
        VK_MEMORY_HEAP_DEVICE_LOCAL_BIT = 0x00000001,
      // Provided by VK_VERSION_1_1
        VK_MEMORY_HEAP_MULTI_INSTANCE_BIT = 0x00000002,
      // Provided by VK_KHR_device_group_creation
        VK_MEMORY_HEAP_MULTI_INSTANCE_BIT_KHR = VK_MEMORY_HEAP_MULTI_INSTANCE_BIT,
    } VkMemoryHeapFlagBits;

- `VK_MEMORY_HEAP_DEVICE_LOCAL_BIT` specifies that the heap corresponds to device-local memory. Device-local memory may have different performance characteristics than host-local memory, and may support different memory property flags.

- `VK_MEMORY_HEAP_MULTI_INSTANCE_BIT` specifies that in a logical device representing more than one physical device, there is a per-physical device instance of the heap memory. By default, an allocation from such a heap will be replicated to each physical device’s instance of the heap.

    // Provided by VK_VERSION_1_0
    typedef VkFlags VkMemoryHeapFlags;

`VkMemoryHeapFlags` is a bitmask type for setting a mask of zero or more VkMemoryHeapFlagBits.

The `VkMemoryType` structure is defined as:

    // Provided by VK_VERSION_1_0
    typedef struct VkMemoryType {
        VkMemoryPropertyFlags    propertyFlags;
        uint32_t                 heapIndex;
    } VkMemoryType;

- `heapIndex` describes which memory heap this memory type corresponds to, and must be less than `memoryHeapCount` from the VkPhysicalDeviceMemoryProperties structure.

- `propertyFlags` is a bitmask of VkMemoryPropertyFlagBits of properties for this memory type.

Bits which may be set in VkMemoryType::`propertyFlags`, indicating properties of a memory heap, are:

    // Provided by VK_VERSION_1_0
    typedef enum VkMemoryPropertyFlagBits {
        VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT = 0x00000001,
        VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT = 0x00000002,
        VK_MEMORY_PROPERTY_HOST_COHERENT_BIT = 0x00000004,
        VK_MEMORY_PROPERTY_HOST_CACHED_BIT = 0x00000008,
        VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT = 0x00000010,
      // Provided by VK_VERSION_1_1
        VK_MEMORY_PROPERTY_PROTECTED_BIT = 0x00000020,
      // Provided by VK_AMD_device_coherent_memory
        VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD = 0x00000040,
      // Provided by VK_AMD_device_coherent_memory
        VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD = 0x00000080,
      // Provided by VK_NV_external_memory_rdma
        VK_MEMORY_PROPERTY_RDMA_CAPABLE_BIT_NV = 0x00000100,
    } VkMemoryPropertyFlagBits;

- `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT` bit specifies that memory allocated with this type is the most efficient for device access. This property will be set if and only if the memory type belongs to a heap with the `VK_MEMORY_HEAP_DEVICE_LOCAL_BIT` set.

- `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` bit specifies that memory allocated with this type can be mapped for host access using vkMapMemory.

- `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` bit specifies that the host cache management commands vkFlushMappedMemoryRanges and vkInvalidateMappedMemoryRanges are not needed to flush host writes to the device or make device writes visible to the host, respectively.

- `VK_MEMORY_PROPERTY_HOST_CACHED_BIT` bit specifies that memory allocated with this type is cached on the host. Host memory accesses to uncached memory are slower than to cached memory, however uncached memory is always host coherent.

- `VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT` bit specifies that the memory type only allows device access to the memory. Memory types must not have both `VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT` and `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` set. Additionally, the object’s backing memory may be provided by the implementation lazily as specified in Lazily Allocated Memory.

- `VK_MEMORY_PROPERTY_PROTECTED_BIT` bit specifies that the memory type only allows device access to the memory, and allows protected queue operations to access the memory. Memory types must not have `VK_MEMORY_PROPERTY_PROTECTED_BIT` set and any of `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` set, or `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` set, or `VK_MEMORY_PROPERTY_HOST_CACHED_BIT` set.

- `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD` bit specifies that device accesses to allocations of this memory type are automatically made available and visible.

- `VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD` bit specifies that memory allocated with this type is not cached on the device. Uncached device memory is always device coherent.

- `VK_MEMORY_PROPERTY_RDMA_CAPABLE_BIT_NV` bit specifies that external devices can access this memory directly.

For any memory allocated with both the `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` and the `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD`, host or device accesses also perform automatic memory domain transfer operations, such that writes are always automatically available and visible to both host and device memory domains.

| Note Device coherence is a useful property for certain debugging use cases (e.g. crash analysis, where performing separate coherence actions could mean values are not reported correctly). However, device coherent accesses may be slower than equivalent accesses without device coherence, particularly if they are also device uncached. For device uncached memory in particular, repeated accesses to the same or neighbouring memory locations over a short time period (e.g. within a frame) may be slower than it would be for the equivalent cached memory type. As such, it is generally inadvisable to use device coherent or device uncached memory except when really needed.

    // Provided by VK_VERSION_1_0
    typedef VkFlags VkMemoryPropertyFlags;

`VkMemoryPropertyFlags` is a bitmask type for setting a mask of zero or more VkMemoryPropertyFlagBits.

If the `VkPhysicalDeviceMemoryBudgetPropertiesEXT` structure is included in the `pNext` chain of VkPhysicalDeviceMemoryProperties2, it is filled with the current memory budgets and usages.

The `VkPhysicalDeviceMemoryBudgetPropertiesEXT` structure is defined as:

    // Provided by VK_EXT_memory_budget
    typedef struct VkPhysicalDeviceMemoryBudgetPropertiesEXT {
        VkStructureType    sType;
        void*              pNext;
        VkDeviceSize       heapBudget[VK_MAX_MEMORY_HEAPS];
        VkDeviceSize       heapUsage[VK_MAX_MEMORY_HEAPS];
    } VkPhysicalDeviceMemoryBudgetPropertiesEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `heapBudget` is an array of `VK_MAX_MEMORY_HEAPS` `VkDeviceSize` values in which memory budgets are returned, with one element for each memory heap. A heap’s budget is a rough estimate of how much memory the process can allocate from that heap before allocations may fail or cause performance degradation. The budget includes any currently allocated device memory.

- `heapUsage` is an array of `VK_MAX_MEMORY_HEAPS` `VkDeviceSize` values in which memory usages are returned, with one element for each memory heap. A heap’s usage is an estimate of how much memory the process is currently using in that heap.

The values returned in this structure are not invariant. The `heapBudget` and `heapUsage` values must be zero for array elements greater than or equal to VkPhysicalDeviceMemoryProperties::`memoryHeapCount`. The `heapBudget` value must be non-zero for array elements less than VkPhysicalDeviceMemoryProperties::`memoryHeapCount`. The `heapBudget` value must be less than or equal to VkMemoryHeap::`size` for each heap.

Valid Usage (Implicit)

- VUID-VkPhysicalDeviceMemoryBudgetPropertiesEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MEMORY_BUDGET_PROPERTIES_EXT`

#### 11.2.2. Device Memory Objects

A Vulkan device operates on data in device memory via memory objects that are represented in the API by a `VkDeviceMemory` handle:

    // Provided by VK_VERSION_1_0
    VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkDeviceMemory)

#### 11.2.3. Device Memory Allocation

To allocate memory objects, call:

    // Provided by VK_VERSION_1_0
    VkResult vkAllocateMemory(
        VkDevice                                    device,
        const VkMemoryAllocateInfo*                 pAllocateInfo,
        const VkAllocationCallbacks*                pAllocator,
        VkDeviceMemory*                             pMemory);

- `device` is the logical device that owns the memory.

- `pAllocateInfo` is a pointer to a VkMemoryAllocateInfo structure describing parameters of the allocation. A successfully returned allocation must use the requested parameters — no substitution is permitted by the implementation.

- `pAllocator` controls host memory allocation as described in the Memory Allocation chapter.

- `pMemory` is a pointer to a VkDeviceMemory handle in which information about the allocated memory is returned.

Allocations returned by `vkAllocateMemory` are guaranteed to meet any alignment requirement of the implementation. For example, if an implementation requires 128 byte alignment for images and 64 byte alignment for buffers, the device memory returned through this mechanism would be 128-byte aligned. This ensures that applications can correctly suballocate objects of different types (with potentially different alignment requirements) in the same memory object.

When memory is allocated, its contents are undefined with the following constraint:

- The contents of unprotected memory must not be a function of the contents of data protected memory objects, even if those memory objects were previously freed.

| Note The contents of memory allocated by one application should not be a function of data from protected memory objects of another application, even if those memory objects were previously freed.

The maximum number of valid memory allocations that can exist simultaneously within a VkDevice may be restricted by implementation- or platform-dependent limits. The `maxMemoryAllocationCount` feature describes the number of allocations that can exist simultaneously before encountering these internal limits.

| Note For historical reasons, if `maxMemoryAllocationCount` is exceeded, some implementations may return `VK_ERROR_TOO_MANY_OBJECTS`. Exceeding this limit will result in undefined behavior, and an application should not rely on the use of the returned error code in order to identify when the limit is reached.

| Note Many protected memory implementations involve complex hardware and system software support, and often have additional and much lower limits on the number of simultaneous protected memory allocations (from memory types with the `VK_MEMORY_PROPERTY_PROTECTED_BIT` property) than for non-protected memory allocations. These limits can be system-wide, and depend on a variety of factors outside of the Vulkan implementation, so they cannot be queried in Vulkan. Applications should use as few allocations as possible from such memory types by suballocating aggressively, and be prepared for allocation failure even when there is apparently plenty of capacity remaining in the memory heap. As a guideline, the Vulkan conformance test suite requires that at least 80 minimum-size allocations can exist concurrently when no other uses of protected memory are active in the system.

Some platforms may have a limit on the maximum size of a single allocation. For example, certain systems may fail to create allocations with a size greater than or equal to 4GB. Such a limit is implementation-dependent, and if such a failure occurs then the error `VK_ERROR_OUT_OF_DEVICE_MEMORY` must be returned. This limit is advertised in VkPhysicalDeviceMaintenance3Properties::`maxMemoryAllocationSize`.

The cumulative memory size allocated to a heap can be limited by the size of the specified heap. In such cases, allocated memory is tracked on a per-device and per-heap basis. Some platforms allow overallocation into other heaps. The overallocation behavior can be specified through the `VK_AMD_memory_overallocation_behavior` extension.

If the VkPhysicalDevicePageableDeviceLocalMemoryFeaturesEXT::`pageableDeviceLocalMemory` feature is enabled, memory allocations made from a heap that includes `VK_MEMORY_HEAP_DEVICE_LOCAL_BIT` in VkMemoryHeap::`flags` may be transparently moved to host-local memory allowing multiple applications to share device-local memory. If there is no space left in device-local memory when this new allocation is made, other allocations may be moved out transparently to make room. The operating system will determine which allocations to move to device-local memory or host-local memory based on platform-specific criteria. To help the operating system make good choices, the application should set the appropriate memory priority with VkMemoryPriorityAllocateInfoEXT and adjust it as necessary with vkSetDeviceMemoryPriorityEXT. Higher priority allocations will moved to device-local memory first.

Memory allocations made on heaps without the `VK_MEMORY_HEAP_DEVICE_LOCAL_BIT` property will not be transparently promoted to device-local memory by the operating system.

Valid Usage

- VUID-vkAllocateMemory-pAllocateInfo-01713
  `pAllocateInfo->allocationSize` must be less than or equal to VkPhysicalDeviceMemoryProperties::`memoryHeaps`[`memindex`].`size` where `memindex` = VkPhysicalDeviceMemoryProperties::`memoryTypes`[`pAllocateInfo->memoryTypeIndex`].`heapIndex` as returned by vkGetPhysicalDeviceMemoryProperties for the VkPhysicalDevice that `device` was created from

- VUID-vkAllocateMemory-pAllocateInfo-01714
  `pAllocateInfo->memoryTypeIndex` must be less than VkPhysicalDeviceMemoryProperties::`memoryTypeCount` as returned by vkGetPhysicalDeviceMemoryProperties for the VkPhysicalDevice that `device` was created from

- VUID-vkAllocateMemory-deviceCoherentMemory-02790
  If the `deviceCoherentMemory` feature is not enabled, `pAllocateInfo->memoryTypeIndex` must not identify a memory type supporting `VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD`

- VUID-vkAllocateMemory-maxMemoryAllocationCount-04101
  There must be less than `VkPhysicalDeviceLimits`::`maxMemoryAllocationCount` device memory allocations currently allocated on the device

Valid Usage (Implicit)

- VUID-vkAllocateMemory-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkAllocateMemory-pAllocateInfo-parameter
  `pAllocateInfo` must be a valid pointer to a valid VkMemoryAllocateInfo structure

- VUID-vkAllocateMemory-pAllocator-parameter
  If `pAllocator` is not `NULL`, `pAllocator` must be a valid pointer to a valid VkAllocationCallbacks structure

- VUID-vkAllocateMemory-pMemory-parameter
  `pMemory` must be a valid pointer to a VkDeviceMemory handle

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_OUT_OF_DEVICE_MEMORY`

  - `VK_ERROR_INVALID_EXTERNAL_HANDLE`

  - `VK_ERROR_INVALID_OPAQUE_CAPTURE_ADDRESS_KHR`

The `VkMemoryAllocateInfo` structure is defined as:

    // Provided by VK_VERSION_1_0
    typedef struct VkMemoryAllocateInfo {
        VkStructureType    sType;
        const void*        pNext;
        VkDeviceSize       allocationSize;
        uint32_t           memoryTypeIndex;
    } VkMemoryAllocateInfo;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `allocationSize` is the size of the allocation in bytes.

- `memoryTypeIndex` is an index identifying a memory type from the `memoryTypes` array of the VkPhysicalDeviceMemoryProperties structure.

The internal data of an allocated device memory object must include a reference to implementation-specific resources, referred to as the memory object’s payload. Applications can also import and export that internal data to and from device memory objects to share data between Vulkan instances and other compatible APIs. A `VkMemoryAllocateInfo` structure defines a memory import operation if its `pNext` chain includes one of the following structures:

- VkImportMemoryWin32HandleInfoKHR with a non-zero `handleType` value

- VkImportMemoryFdInfoKHR with a non-zero `handleType` value

- VkImportMemoryHostPointerInfoEXT with a non-zero `handleType` value

- VkImportAndroidHardwareBufferInfoANDROID with a non-`NULL` `buffer` value

- VkImportMemoryZirconHandleInfoFUCHSIA with a non-zero `handleType` value

- VkImportMemoryBufferCollectionFUCHSIA

If the parameters define an import operation and the external handle type is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_KMT_BIT`, or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D12_RESOURCE_BIT`, `allocationSize` is ignored. The implementation must query the size of these allocations from the OS.

Whether device memory objects constructed via a memory import operation hold a reference to their payload depends on the properties of the handle type used to perform the import, as defined below for each valid handle type. Importing memory must not modify the content of the memory. Implementations must ensure that importing memory does not enable the importing Vulkan instance to access any memory or resources in other Vulkan instances other than that corresponding to the memory object imported. Implementations must also ensure accessing imported memory which has not been initialized does not allow the importing Vulkan instance to obtain data from the exporting Vulkan instance or vice-versa.

| Note How exported and imported memory is isolated is left to the implementation, but applications should be aware that such isolation may prevent implementations from placing multiple exportable memory objects in the same physical or virtual page. Hence, applications should avoid creating many small external memory objects whenever possible.

Importing memory must not increase overall heap usage within a system. However, it must affect the following per-process values:

- VkPhysicalDeviceMaintenance3Properties::`maxMemoryAllocationCount`

- VkPhysicalDeviceMemoryBudgetPropertiesEXT::`heapUsage`

When performing a memory import operation, it is the responsibility of the application to ensure the external handles and their associated payloads meet all valid usage requirements. However, implementations must perform sufficient validation of external handles and payloads to ensure that the operation results in a valid memory object which will not cause program termination, device loss, queue stalls, or corruption of other resources when used as allowed according to its allocation parameters. If the external handle provided does not meet these requirements, the implementation must fail the memory import operation with the error code `VK_ERROR_INVALID_EXTERNAL_HANDLE`. If the parameters define an export operation and the external handle type is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID`, implementations should not strictly follow `memoryTypeIndex`. Instead, they should modify the allocation internally to use the required memory type for the application’s given usage. This is because for an export operation, there is currently no way for the client to know the memory type index before allocating.

Valid Usage

- VUID-VkMemoryAllocateInfo-None-06657
  The parameters must not define more than one import operation

- VUID-VkMemoryAllocateInfo-buffer-06380
  If the parameters define an import operation from an VkBufferCollectionFUCHSIA, and VkMemoryDedicatedAllocateInfo::`buffer` is present and non-NULL, VkImportMemoryBufferCollectionFUCHSIA::`collection` and VkImportMemoryBufferCollectionFUCHSIA::`index` must match VkBufferCollectionBufferCreateInfoFUCHSIA::`collection` and VkBufferCollectionBufferCreateInfoFUCHSIA::`index`, respectively, of the VkBufferCollectionBufferCreateInfoFUCHSIA structure used to create the VkMemoryDedicatedAllocateInfo::`buffer`

- VUID-VkMemoryAllocateInfo-image-06381
  If the parameters define an import operation from an VkBufferCollectionFUCHSIA, and VkMemoryDedicatedAllocateInfo::`image` is present and non-NULL, VkImportMemoryBufferCollectionFUCHSIA::`collection` and VkImportMemoryBufferCollectionFUCHSIA::`index` must match VkBufferCollectionImageCreateInfoFUCHSIA::`collection` and VkBufferCollectionImageCreateInfoFUCHSIA::`index`, respectively, of the VkBufferCollectionImageCreateInfoFUCHSIA structure used to create the VkMemoryDedicatedAllocateInfo::`image`

- VUID-VkMemoryAllocateInfo-allocationSize-06382
  If the parameters define an import operation from an VkBufferCollectionFUCHSIA, `allocationSize` must match VkMemoryRequirements::`size` value retrieved by vkGetImageMemoryRequirements or vkGetBufferMemoryRequirements for image-based or buffer-based collections respectively

- VUID-VkMemoryAllocateInfo-pNext-06383
  If the parameters define an import operation from an VkBufferCollectionFUCHSIA, the `pNext` chain must include a VkMemoryDedicatedAllocateInfo structure with either its `image` or `buffer` field set to a value other than VK_NULL_HANDLE.

- VUID-VkMemoryAllocateInfo-image-06384
  If the parameters define an import operation from an VkBufferCollectionFUCHSIA and VkMemoryDedicatedAllocateInfo::`image` is not VK_NULL_HANDLE, the `image` must be created with a VkBufferCollectionImageCreateInfoFUCHSIA structure chained to its VkImageCreateInfo::`pNext` pointer

- VUID-VkMemoryAllocateInfo-buffer-06385
  If the parameters define an import operation from an VkBufferCollectionFUCHSIA and VkMemoryDedicatedAllocateInfo::`buffer` is not VK_NULL_HANDLE, the `buffer` must be created with a VkBufferCollectionBufferCreateInfoFUCHSIA structure chained to its VkBufferCreateInfo::`pNext` pointer

- VUID-VkMemoryAllocateInfo-memoryTypeIndex-06386
  If the parameters define an import operation from an VkBufferCollectionFUCHSIA, `memoryTypeIndex` must be from VkBufferCollectionPropertiesFUCHSIA as retrieved by vkGetBufferCollectionPropertiesFUCHSIA.

- VUID-VkMemoryAllocateInfo-pNext-00639
  If the `pNext` chain includes a `VkExportMemoryAllocateInfo` structure, and any of the handle types specified in `VkExportMemoryAllocateInfo`::`handleTypes` require a dedicated allocation, as reported by vkGetPhysicalDeviceImageFormatProperties2 in `VkExternalImageFormatProperties`::`externalMemoryProperties.externalMemoryFeatures` or `VkExternalBufferProperties`::`externalMemoryProperties.externalMemoryFeatures`, the `pNext` chain must include a `VkMemoryDedicatedAllocateInfo` or `VkDedicatedAllocationMemoryAllocateInfoNV` structure with either its `image` or `buffer` member set to a value other than VK_NULL_HANDLE

- VUID-VkMemoryAllocateInfo-pNext-00640
  If the `pNext` chain includes a VkExportMemoryAllocateInfo structure, it must not include a VkExportMemoryAllocateInfoNV or VkExportMemoryWin32HandleInfoNV structure

- VUID-VkMemoryAllocateInfo-pNext-00641
  If the `pNext` chain includes a VkImportMemoryWin32HandleInfoKHR structure, it must not include a VkImportMemoryWin32HandleInfoNV structure

- VUID-VkMemoryAllocateInfo-allocationSize-01742
  If the parameters define an import operation, the external handle specified was created by the Vulkan API, and the external handle type is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT`, then the values of `allocationSize` and `memoryTypeIndex` must match those specified when the payload being imported was created

- VUID-VkMemoryAllocateInfo-None-00643
  If the parameters define an import operation and the external handle specified was created by the Vulkan API, the device mask specified by VkMemoryAllocateFlagsInfo must match the mask specified when the payload being imported was allocated

- VUID-VkMemoryAllocateInfo-None-00644
  If the parameters define an import operation and the external handle specified was created by the Vulkan API, the list of physical devices that comprise the logical device passed to vkAllocateMemory must match the list of physical devices that comprise the logical device on which the payload was originally allocated

- VUID-VkMemoryAllocateInfo-memoryTypeIndex-00645
  If the parameters define an import operation and the external handle is an NT handle or a global share handle created outside of the Vulkan API, the value of `memoryTypeIndex` must be one of those returned by vkGetMemoryWin32HandlePropertiesKHR

- VUID-VkMemoryAllocateInfo-allocationSize-01743
  If the parameters define an import operation, the external handle was created by the Vulkan API, and the external handle type is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT` or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_KMT_BIT`, then the values of `allocationSize` and `memoryTypeIndex` must match those specified when the payload being imported was created

- VUID-VkMemoryAllocateInfo-allocationSize-00647
  If the parameters define an import operation and the external handle type is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D12_HEAP_BIT`, `allocationSize` must match the size specified when creating the Direct3D 12 heap from which the payload was extracted

- VUID-VkMemoryAllocateInfo-memoryTypeIndex-00648
  If the parameters define an import operation and the external handle is a POSIX file descriptor created outside of the Vulkan API, the value of `memoryTypeIndex` must be one of those returned by vkGetMemoryFdPropertiesKHR

- VUID-VkMemoryAllocateInfo-memoryTypeIndex-01872
  If the `protectedMemory` feature is not enabled, the `VkMemoryAllocateInfo`::`memoryTypeIndex` must not indicate a memory type that reports `VK_MEMORY_PROPERTY_PROTECTED_BIT`

- VUID-VkMemoryAllocateInfo-memoryTypeIndex-01744
  If the parameters define an import operation and the external handle is a host pointer, the value of `memoryTypeIndex` must be one of those returned by vkGetMemoryHostPointerPropertiesEXT

- VUID-VkMemoryAllocateInfo-allocationSize-01745
  If the parameters define an import operation and the external handle is a host pointer, `allocationSize` must be an integer multiple of `VkPhysicalDeviceExternalMemoryHostPropertiesEXT`::`minImportedHostPointerAlignment`

- VUID-VkMemoryAllocateInfo-pNext-02805
  If the parameters define an import operation and the external handle is a host pointer, the `pNext` chain must not include a VkDedicatedAllocationMemoryAllocateInfoNV structure with either its `image` or `buffer` field set to a value other than VK_NULL_HANDLE

- VUID-VkMemoryAllocateInfo-pNext-02806
  If the parameters define an import operation and the external handle is a host pointer, the `pNext` chain must not include a VkMemoryDedicatedAllocateInfo structure with either its `image` or `buffer` field set to a value other than VK_NULL_HANDLE

- VUID-VkMemoryAllocateInfo-allocationSize-02383
  If the parameters define an import operation and the external handle type is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID`, `allocationSize` must be the size returned by vkGetAndroidHardwareBufferPropertiesANDROID for the Android hardware buffer

- VUID-VkMemoryAllocateInfo-pNext-02384
  If the parameters define an import operation and the external handle type is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID`, and the `pNext` chain does not include a VkMemoryDedicatedAllocateInfo structure or VkMemoryDedicatedAllocateInfo::`image` is VK_NULL_HANDLE, the Android hardware buffer must have a `AHardwareBuffer_Desc`::`format` of `AHARDWAREBUFFER_FORMAT_BLOB` and a `AHardwareBuffer_Desc`::`usage` that includes `AHARDWAREBUFFER_USAGE_GPU_DATA_BUFFER`

- VUID-VkMemoryAllocateInfo-memoryTypeIndex-02385
  If the parameters define an import operation and the external handle type is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID`, `memoryTypeIndex` must be one of those returned by vkGetAndroidHardwareBufferPropertiesANDROID for the Android hardware buffer

- VUID-VkMemoryAllocateInfo-pNext-01874
  If the parameters do not define an import operation, and the `pNext` chain includes a `VkExportMemoryAllocateInfo` structure with `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID` included in its `handleTypes` member, and the `pNext` chain includes a VkMemoryDedicatedAllocateInfo structure with `image` not equal to VK_NULL_HANDLE, then `allocationSize` must be `0`, otherwise `allocationSize` must be greater than `0`

- VUID-VkMemoryAllocateInfo-pNext-02386
  If the parameters define an import operation, the external handle is an Android hardware buffer, and the `pNext` chain includes a VkMemoryDedicatedAllocateInfo with `image` that is not VK_NULL_HANDLE, the Android hardware buffer’s `AHardwareBuffer`::`usage` must include at least one of `AHARDWAREBUFFER_USAGE_GPU_FRAMEBUFFER`, `AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE` or `AHARDWAREBUFFER_USAGE_GPU_DATA_BUFFER`

- VUID-VkMemoryAllocateInfo-pNext-02387
  If the parameters define an import operation, the external handle is an Android hardware buffer, and the `pNext` chain includes a VkMemoryDedicatedAllocateInfo with `image` that is not VK_NULL_HANDLE, the format of `image` must be `VK_FORMAT_UNDEFINED` or the format returned by vkGetAndroidHardwareBufferPropertiesANDROID in VkAndroidHardwareBufferFormatPropertiesANDROID::`format` for the Android hardware buffer

- VUID-VkMemoryAllocateInfo-pNext-02388
  If the parameters define an import operation, the external handle is an Android hardware buffer, and the `pNext` chain includes a VkMemoryDedicatedAllocateInfo structure with `image` that is not VK_NULL_HANDLE, the width, height, and array layer dimensions of `image` and the Android hardware buffer’s `AHardwareBuffer_Desc` must be identical

- VUID-VkMemoryAllocateInfo-pNext-02389
  If the parameters define an import operation, the external handle is an Android hardware buffer, and the `pNext` chain includes a VkMemoryDedicatedAllocateInfo structure with `image` that is not VK_NULL_HANDLE, and the Android hardware buffer’s `AHardwareBuffer`::`usage` includes `AHARDWAREBUFFER_USAGE_GPU_MIPMAP_COMPLETE`, the `image` must have a complete mipmap chain

- VUID-VkMemoryAllocateInfo-pNext-02586
  If the parameters define an import operation, the external handle is an Android hardware buffer, and the `pNext` chain includes a VkMemoryDedicatedAllocateInfo structure with `image` that is not VK_NULL_HANDLE, and the Android hardware buffer’s `AHardwareBuffer`::`usage` does not include `AHARDWAREBUFFER_USAGE_GPU_MIPMAP_COMPLETE`, the `image` must have exactly one mipmap level

- VUID-VkMemoryAllocateInfo-pNext-02390
  If the parameters define an import operation, the external handle is an Android hardware buffer, and the `pNext` chain includes a VkMemoryDedicatedAllocateInfo structure with `image` that is not VK_NULL_HANDLE, each bit set in the usage of `image` must be listed in AHardwareBuffer Usage Equivalence, and if there is a corresponding `AHARDWAREBUFFER_USAGE` bit listed that bit must be included in the Android hardware buffer’s `AHardwareBuffer_Desc`::`usage`

- VUID-VkMemoryAllocateInfo-opaqueCaptureAddress-03329
  If VkMemoryOpaqueCaptureAddressAllocateInfo::`opaqueCaptureAddress` is not zero, `VkMemoryAllocateFlagsInfo`::`flags` must include `VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_CAPTURE_REPLAY_BIT`

- VUID-VkMemoryAllocateInfo-flags-03330
  If `VkMemoryAllocateFlagsInfo`::`flags` includes `VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_CAPTURE_REPLAY_BIT`, the `bufferDeviceAddressCaptureReplay` feature must be enabled

- VUID-VkMemoryAllocateInfo-flags-03331
  If `VkMemoryAllocateFlagsInfo`::`flags` includes `VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT`, the `bufferDeviceAddress` feature must be enabled

- VUID-VkMemoryAllocateInfo-pNext-03332
  If the `pNext` chain includes a `VkImportMemoryHostPointerInfoEXT` structure, VkMemoryOpaqueCaptureAddressAllocateInfo::`opaqueCaptureAddress` must be zero

- VUID-VkMemoryAllocateInfo-opaqueCaptureAddress-03333
  If the parameters define an import operation, VkMemoryOpaqueCaptureAddressAllocateInfo::`opaqueCaptureAddress` must be zero

- VUID-VkMemoryAllocateInfo-None-04749
  If the parameters define an import operation and the external handle type is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ZIRCON_VMO_BIT_FUCHSIA`, the value of `memoryTypeIndex` must be an index identifying a memory type from the `memoryTypeBits` field of the VkMemoryZirconHandlePropertiesFUCHSIA structure populated by a call to vkGetMemoryZirconHandlePropertiesFUCHSIA

- VUID-VkMemoryAllocateInfo-allocationSize-04750
  If the parameters define an import operation and the external handle type is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ZIRCON_VMO_BIT_FUCHSIA`, the value of `allocationSize` must be greater than `0` and must be less than or equal to the size of the VMO as determined by `zx_vmo_get_size`(`handle`) where `handle` is the VMO handle to the imported external memory

- VUID-VkMemoryAllocateInfo-pNext-06780
  If the `pNext` chain includes a VkExportMetalObjectCreateInfoEXT structure, its `exportObjectType` member must be `VK_EXPORT_METAL_OBJECT_TYPE_METAL_BUFFER_BIT_EXT`.

Valid Usage (Implicit)

- VUID-VkMemoryAllocateInfo-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO`

- VUID-VkMemoryAllocateInfo-pNext-pNext
  Each `pNext` member of any structure (including this one) in the `pNext` chain must be either `NULL` or a pointer to a valid instance of VkDedicatedAllocationMemoryAllocateInfoNV, VkExportMemoryAllocateInfo, VkExportMemoryAllocateInfoNV, VkExportMemoryWin32HandleInfoKHR, VkExportMemoryWin32HandleInfoNV, VkExportMetalObjectCreateInfoEXT, VkImportAndroidHardwareBufferInfoANDROID, VkImportMemoryBufferCollectionFUCHSIA, VkImportMemoryFdInfoKHR, VkImportMemoryHostPointerInfoEXT, VkImportMemoryWin32HandleInfoKHR, VkImportMemoryWin32HandleInfoNV, VkImportMemoryZirconHandleInfoFUCHSIA, VkImportMetalBufferInfoEXT, VkMemoryAllocateFlagsInfo, VkMemoryDedicatedAllocateInfo, VkMemoryOpaqueCaptureAddressAllocateInfo, or VkMemoryPriorityAllocateInfoEXT

- VUID-VkMemoryAllocateInfo-sType-unique
  The `sType` value of each struct in the `pNext` chain must be unique, with the exception of structures of type VkExportMetalObjectCreateInfoEXT

If the `pNext` chain includes a `VkMemoryDedicatedAllocateInfo` structure, then that structure includes a handle of the sole buffer or image resource that the memory can be bound to.

The `VkMemoryDedicatedAllocateInfo` structure is defined as:

    // Provided by VK_VERSION_1_1
    typedef struct VkMemoryDedicatedAllocateInfo {
        VkStructureType    sType;
        const void*        pNext;
        VkImage            image;
        VkBuffer           buffer;
    } VkMemoryDedicatedAllocateInfo;

or the equivalent

    // Provided by VK_KHR_dedicated_allocation
    typedef VkMemoryDedicatedAllocateInfo VkMemoryDedicatedAllocateInfoKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `image` is VK_NULL_HANDLE or a handle of an image which this memory will be bound to.

- `buffer` is VK_NULL_HANDLE or a handle of a buffer which this memory will be bound to.

Valid Usage

- VUID-VkMemoryDedicatedAllocateInfo-image-01432
  At least one of `image` and `buffer` must be VK_NULL_HANDLE

- VUID-VkMemoryDedicatedAllocateInfo-image-02964
  If `image` is not VK_NULL_HANDLE and the memory is not an imported Android Hardware Buffer, `VkMemoryAllocateInfo`::`allocationSize` must equal the `VkMemoryRequirements`::`size` of the image

- VUID-VkMemoryDedicatedAllocateInfo-image-01434
  If `image` is not VK_NULL_HANDLE, `image` must have been created without `VK_IMAGE_CREATE_SPARSE_BINDING_BIT` set in VkImageCreateInfo::`flags`

- VUID-VkMemoryDedicatedAllocateInfo-buffer-02965
  If `buffer` is not VK_NULL_HANDLE and the memory is not an imported Android Hardware Buffer, `VkMemoryAllocateInfo`::`allocationSize` must equal the `VkMemoryRequirements`::`size` of the buffer

- VUID-VkMemoryDedicatedAllocateInfo-buffer-01436
  If `buffer` is not VK_NULL_HANDLE, `buffer` must have been created without `VK_BUFFER_CREATE_SPARSE_BINDING_BIT` set in VkBufferCreateInfo::`flags`

- VUID-VkMemoryDedicatedAllocateInfo-image-01876
  If `image` is not VK_NULL_HANDLE and VkMemoryAllocateInfo defines a memory import operation with handle type `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_KMT_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_KMT_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D12_HEAP_BIT`, or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D12_RESOURCE_BIT`, and the external handle was created by the Vulkan API, then the memory being imported must also be a dedicated image allocation and `image` must be identical to the image associated with the imported memory

- VUID-VkMemoryDedicatedAllocateInfo-buffer-01877
  If `buffer` is not VK_NULL_HANDLE and VkMemoryAllocateInfo defines a memory import operation with handle type `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_KMT_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_KMT_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D12_HEAP_BIT`, or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D12_RESOURCE_BIT`, and the external handle was created by the Vulkan API, then the memory being imported must also be a dedicated buffer allocation and `buffer` must be identical to the buffer associated with the imported memory

- VUID-VkMemoryDedicatedAllocateInfo-image-01878
  If `image` is not VK_NULL_HANDLE and VkMemoryAllocateInfo defines a memory import operation with handle type `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT`, the memory being imported must also be a dedicated image allocation and `image` must be identical to the image associated with the imported memory

- VUID-VkMemoryDedicatedAllocateInfo-buffer-01879
  If `buffer` is not VK_NULL_HANDLE and VkMemoryAllocateInfo defines a memory import operation with handle type `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT`, the memory being imported must also be a dedicated buffer allocation and `buffer` must be identical to the buffer associated with the imported memory

- VUID-VkMemoryDedicatedAllocateInfo-image-01797
  If `image` is not VK_NULL_HANDLE, `image` must not have been created with `VK_IMAGE_CREATE_DISJOINT_BIT` set in VkImageCreateInfo::`flags`

- VUID-VkMemoryDedicatedAllocateInfo-image-04751
  If `image` is not VK_NULL_HANDLE and VkMemoryAllocateInfo defines a memory import operation with handle type `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ZIRCON_VMO_BIT_FUCHSIA`, the memory being imported must also be a dedicated image allocation and `image` must be identical to the image associated with the imported memory

- VUID-VkMemoryDedicatedAllocateInfo-buffer-04752
  If `buffer` is not VK_NULL_HANDLE and VkMemoryAllocateInfo defines a memory import operation with handle type `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ZIRCON_VMO_BIT_FUCHSIA`, the memory being imported must also be a dedicated buffer allocation and `buffer` must be identical to the buffer associated with the imported memory

Valid Usage (Implicit)

- VUID-VkMemoryDedicatedAllocateInfo-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_DEDICATED_ALLOCATE_INFO`

- VUID-VkMemoryDedicatedAllocateInfo-image-parameter
  If `image` is not VK_NULL_HANDLE, `image` must be a valid VkImage handle

- VUID-VkMemoryDedicatedAllocateInfo-buffer-parameter
  If `buffer` is not VK_NULL_HANDLE, `buffer` must be a valid VkBuffer handle

- VUID-VkMemoryDedicatedAllocateInfo-commonparent
  Both of `buffer`, and `image` that are valid handles of non-ignored parameters must have been created, allocated, or retrieved from the same VkDevice

If the `pNext` chain includes a `VkDedicatedAllocationMemoryAllocateInfoNV` structure, then that structure includes a handle of the sole buffer or image resource that the memory can be bound to.

The `VkDedicatedAllocationMemoryAllocateInfoNV` structure is defined as:

    // Provided by VK_NV_dedicated_allocation
    typedef struct VkDedicatedAllocationMemoryAllocateInfoNV {
        VkStructureType    sType;
        const void*        pNext;
        VkImage            image;
        VkBuffer           buffer;
    } VkDedicatedAllocationMemoryAllocateInfoNV;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `image` is VK_NULL_HANDLE or a handle of an image which this memory will be bound to.

- `buffer` is VK_NULL_HANDLE or a handle of a buffer which this memory will be bound to.

Valid Usage

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-image-00649
  At least one of `image` and `buffer` must be VK_NULL_HANDLE

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-image-00650
  If `image` is not VK_NULL_HANDLE, the image must have been created with VkDedicatedAllocationImageCreateInfoNV::`dedicatedAllocation` equal to `VK_TRUE`

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-buffer-00651
  If `buffer` is not VK_NULL_HANDLE, the buffer must have been created with VkDedicatedAllocationBufferCreateInfoNV::`dedicatedAllocation` equal to `VK_TRUE`

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-image-00652
  If `image` is not VK_NULL_HANDLE, `VkMemoryAllocateInfo`::`allocationSize` must equal the `VkMemoryRequirements`::`size` of the image

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-buffer-00653
  If `buffer` is not VK_NULL_HANDLE, `VkMemoryAllocateInfo`::`allocationSize` must equal the `VkMemoryRequirements`::`size` of the buffer

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-image-00654
  If `image` is not VK_NULL_HANDLE and VkMemoryAllocateInfo defines a memory import operation, the memory being imported must also be a dedicated image allocation and `image` must be identical to the image associated with the imported memory

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-buffer-00655
  If `buffer` is not VK_NULL_HANDLE and VkMemoryAllocateInfo defines a memory import operation, the memory being imported must also be a dedicated buffer allocation and `buffer` must be identical to the buffer associated with the imported memory

Valid Usage (Implicit)

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_MEMORY_ALLOCATE_INFO_NV`

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-image-parameter
  If `image` is not VK_NULL_HANDLE, `image` must be a valid VkImage handle

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-buffer-parameter
  If `buffer` is not VK_NULL_HANDLE, `buffer` must be a valid VkBuffer handle

- VUID-VkDedicatedAllocationMemoryAllocateInfoNV-commonparent
  Both of `buffer`, and `image` that are valid handles of non-ignored parameters must have been created, allocated, or retrieved from the same VkDevice

If the `pNext` chain includes a `VkMemoryPriorityAllocateInfoEXT` structure, then that structure includes a priority for the memory.

The `VkMemoryPriorityAllocateInfoEXT` structure is defined as:

    // Provided by VK_EXT_memory_priority
    typedef struct VkMemoryPriorityAllocateInfoEXT {
        VkStructureType    sType;
        const void*        pNext;
        float              priority;
    } VkMemoryPriorityAllocateInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `priority` is a floating-point value between `0` and `1`, indicating the priority of the allocation relative to other memory allocations. Larger values are higher priority. The granularity of the priorities is implementation-dependent.

Memory allocations with higher priority may be more likely to stay in device-local memory when the system is under memory pressure.

If this structure is not included, it is as if the `priority` value were `0.5`.

Valid Usage

- VUID-VkMemoryPriorityAllocateInfoEXT-priority-02602
  `priority` must be between `0` and `1`, inclusive

Valid Usage (Implicit)

- VUID-VkMemoryPriorityAllocateInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_PRIORITY_ALLOCATE_INFO_EXT`

To modify the priority of an existing memory allocation, call:

    // Provided by VK_EXT_pageable_device_local_memory
    void vkSetDeviceMemoryPriorityEXT(
        VkDevice                                    device,
        VkDeviceMemory                              memory,
        float                                       priority);

- `device` is the logical device that owns the memory.

- `memory` is the VkDeviceMemory object to which the new priority will be applied.

- `priority` is a floating-point value between `0` and `1`, indicating the priority of the allocation relative to other memory allocations. Larger values are higher priority. The granularity of the priorities is implementation-dependent.

Memory allocations with higher priority may be more likely to stay in device-local memory when the system is under memory pressure.

Valid Usage

- VUID-vkSetDeviceMemoryPriorityEXT-priority-06258
  `priority` must be between `0` and `1`, inclusive

Valid Usage (Implicit)

- VUID-vkSetDeviceMemoryPriorityEXT-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkSetDeviceMemoryPriorityEXT-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

- VUID-vkSetDeviceMemoryPriorityEXT-memory-parent
  `memory` must have been created, allocated, or retrieved from `device`

When allocating memory whose payload may be exported to another process or Vulkan instance, add a VkExportMemoryAllocateInfo structure to the `pNext` chain of the VkMemoryAllocateInfo structure, specifying the handle types that may be exported.

The VkExportMemoryAllocateInfo structure is defined as:

    // Provided by VK_VERSION_1_1
    typedef struct VkExportMemoryAllocateInfo {
        VkStructureType                    sType;
        const void*                        pNext;
        VkExternalMemoryHandleTypeFlags    handleTypes;
    } VkExportMemoryAllocateInfo;

or the equivalent

    // Provided by VK_KHR_external_memory
    typedef VkExportMemoryAllocateInfo VkExportMemoryAllocateInfoKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `handleTypes` is zero or a bitmask of VkExternalMemoryHandleTypeFlagBits specifying one or more memory handle types the application can export from the resulting allocation. The application can request multiple handle types for the same allocation.

Valid Usage

- VUID-VkExportMemoryAllocateInfo-handleTypes-00656
  The bits in `handleTypes` must be supported and compatible, as reported by VkExternalImageFormatProperties or VkExternalBufferProperties

Valid Usage (Implicit)

- VUID-VkExportMemoryAllocateInfo-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_MEMORY_ALLOCATE_INFO`

- VUID-VkExportMemoryAllocateInfo-handleTypes-parameter
  `handleTypes` must be a valid combination of VkExternalMemoryHandleTypeFlagBits values

When allocating memory that may be exported to another process or Vulkan instance, add a VkExportMemoryAllocateInfoNV structure to the `pNext` chain of the VkMemoryAllocateInfo structure, specifying the handle types that may be exported.

The VkExportMemoryAllocateInfoNV structure is defined as:

    // Provided by VK_NV_external_memory
    typedef struct VkExportMemoryAllocateInfoNV {
        VkStructureType                      sType;
        const void*                          pNext;
        VkExternalMemoryHandleTypeFlagsNV    handleTypes;
    } VkExportMemoryAllocateInfoNV;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `handleTypes` is a bitmask of VkExternalMemoryHandleTypeFlagBitsNV specifying one or more memory handle types that may be exported. Multiple handle types may be requested for the same allocation as long as they are compatible, as reported by vkGetPhysicalDeviceExternalImageFormatPropertiesNV.

Valid Usage (Implicit)

- VUID-VkExportMemoryAllocateInfoNV-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_MEMORY_ALLOCATE_INFO_NV`

- VUID-VkExportMemoryAllocateInfoNV-handleTypes-parameter
  `handleTypes` must be a valid combination of VkExternalMemoryHandleTypeFlagBitsNV values

#### 11.2.4. Win32 External Memory

To specify additional attributes of NT handles exported from a memory object, add a VkExportMemoryWin32HandleInfoKHR structure to the `pNext` chain of the VkMemoryAllocateInfo structure. The `VkExportMemoryWin32HandleInfoKHR` structure is defined as:

    // Provided by VK_KHR_external_memory_win32
    typedef struct VkExportMemoryWin32HandleInfoKHR {
        VkStructureType               sType;
        const void*                   pNext;
        const SECURITY_ATTRIBUTES*    pAttributes;
        DWORD                         dwAccess;
        LPCWSTR                       name;
    } VkExportMemoryWin32HandleInfoKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `pAttributes` is a pointer to a Windows `SECURITY_ATTRIBUTES` structure specifying security attributes of the handle.

- `dwAccess` is a `DWORD` specifying access rights of the handle.

- `name` is a null-terminated UTF-16 string to associate with the payload referenced by NT handles exported from the created memory.

If VkExportMemoryAllocateInfo is not included in the same `pNext` chain, this structure is ignored.

If VkExportMemoryAllocateInfo is included in the `pNext` chain of VkMemoryAllocateInfo with a Windows `handleType`, but either `VkExportMemoryWin32HandleInfoKHR` is not included in the `pNext` chain, or if it is but `pAttributes` is set to `NULL`, default security descriptor values will be used, and child processes created by the application will not inherit the handle, as described in the MSDN documentation for “Synchronization Object Security and Access Rights”1. Further, if the structure is not present, the access rights used depend on the handle type.

For handles of the following types:

- `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT`

The implementation must ensure the access rights allow read and write access to the memory.

1

  https://docs.microsoft.com/en-us/windows/win32/sync/synchronization-object-security-and-access-rights

Valid Usage

- VUID-VkExportMemoryWin32HandleInfoKHR-handleTypes-00657
  If VkExportMemoryAllocateInfo::`handleTypes` does not include `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT`, a `VkExportMemoryWin32HandleInfoKHR` structure must not be included in the `pNext` chain of VkMemoryAllocateInfo

Valid Usage (Implicit)

- VUID-VkExportMemoryWin32HandleInfoKHR-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_MEMORY_WIN32_HANDLE_INFO_KHR`

- VUID-VkExportMemoryWin32HandleInfoKHR-pAttributes-parameter
  If `pAttributes` is not `NULL`, `pAttributes` must be a valid pointer to a valid `SECURITY_ATTRIBUTES` value

To import memory from a Windows handle, add a VkImportMemoryWin32HandleInfoKHR structure to the `pNext` chain of the VkMemoryAllocateInfo structure.

The `VkImportMemoryWin32HandleInfoKHR` structure is defined as:

    // Provided by VK_KHR_external_memory_win32
    typedef struct VkImportMemoryWin32HandleInfoKHR {
        VkStructureType                       sType;
        const void*                           pNext;
        VkExternalMemoryHandleTypeFlagBits    handleType;
        HANDLE                                handle;
        LPCWSTR                               name;
    } VkImportMemoryWin32HandleInfoKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the type of `handle` or `name`.

- `handle` is `NULL` or the external handle to import.

- `name` is `NULL` or a null-terminated UTF-16 string naming the payload to import.

Importing memory object payloads from Windows handles does not transfer ownership of the handle to the Vulkan implementation. For handle types defined as NT handles, the application must release handle ownership using the `CloseHandle` system call when the handle is no longer needed. For handle types defined as NT handles, the imported memory object holds a reference to its payload.

| Note Non-NT handle import operations do not add a reference to their associated payload. If the original object owning the payload is destroyed, all resources and handles sharing that payload will become invalid.

Applications can import the same payload into multiple instances of Vulkan, into the same instance from which it was exported, and multiple times into a given Vulkan instance. In all cases, each import operation must create a distinct `VkDeviceMemory` object.

Valid Usage

- VUID-VkImportMemoryWin32HandleInfoKHR-handleType-00658
  If `handleType` is not `0`, it must be supported for import, as reported by VkExternalImageFormatProperties or VkExternalBufferProperties

- VUID-VkImportMemoryWin32HandleInfoKHR-handle-00659
  The memory from which `handle` was exported, or the memory named by `name` must have been created on the same underlying physical device as `device`

- VUID-VkImportMemoryWin32HandleInfoKHR-handleType-00660
  If `handleType` is not `0`, it must be defined as an NT handle or a global share handle

- VUID-VkImportMemoryWin32HandleInfoKHR-handleType-01439
  If `handleType` is not `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_BIT`, `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D12_HEAP_BIT`, or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D12_RESOURCE_BIT`, `name` must be `NULL`

- VUID-VkImportMemoryWin32HandleInfoKHR-handleType-01440
  If `handleType` is not `0` and `handle` is `NULL`, `name` must name a valid memory resource of the type specified by `handleType`

- VUID-VkImportMemoryWin32HandleInfoKHR-handleType-00661
  If `handleType` is not `0` and `name` is `NULL`, `handle` must be a valid handle of the type specified by `handleType`

- VUID-VkImportMemoryWin32HandleInfoKHR-handle-01441
  if `handle` is not `NULL`, `name` must be `NULL`

- VUID-VkImportMemoryWin32HandleInfoKHR-handle-01518
  If `handle` is not `NULL`, it must obey any requirements listed for `handleType` in external memory handle types compatibility

- VUID-VkImportMemoryWin32HandleInfoKHR-name-01519
  If `name` is not `NULL`, it must obey any requirements listed for `handleType` in external memory handle types compatibility

Valid Usage (Implicit)

- VUID-VkImportMemoryWin32HandleInfoKHR-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_IMPORT_MEMORY_WIN32_HANDLE_INFO_KHR`

- VUID-VkImportMemoryWin32HandleInfoKHR-handleType-parameter
  If `handleType` is not `0`, `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

To export a Windows handle representing the payload of a Vulkan device memory object, call:

    // Provided by VK_KHR_external_memory_win32
    VkResult vkGetMemoryWin32HandleKHR(
        VkDevice                                    device,
        const VkMemoryGetWin32HandleInfoKHR*        pGetWin32HandleInfo,
        HANDLE*                                     pHandle);

- `device` is the logical device that created the device memory being exported.

- `pGetWin32HandleInfo` is a pointer to a VkMemoryGetWin32HandleInfoKHR structure containing parameters of the export operation.

- `pHandle` will return the Windows handle representing the payload of the device memory object.

For handle types defined as NT handles, the handles returned by `vkGetMemoryWin32HandleKHR` are owned by the application and hold a reference to their payload. To avoid leaking resources, the application must release ownership of them using the `CloseHandle` system call when they are no longer needed.

| Note Non-NT handle types do not add a reference to their associated payload. If the original object owning the payload is destroyed, all resources and handles sharing that payload will become invalid.

Valid Usage (Implicit)

- VUID-vkGetMemoryWin32HandleKHR-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryWin32HandleKHR-pGetWin32HandleInfo-parameter
  `pGetWin32HandleInfo` must be a valid pointer to a valid VkMemoryGetWin32HandleInfoKHR structure

- VUID-vkGetMemoryWin32HandleKHR-pHandle-parameter
  `pHandle` must be a valid pointer to a `HANDLE` value

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_TOO_MANY_OBJECTS`

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

The `VkMemoryGetWin32HandleInfoKHR` structure is defined as:

    // Provided by VK_KHR_external_memory_win32
    typedef struct VkMemoryGetWin32HandleInfoKHR {
        VkStructureType                       sType;
        const void*                           pNext;
        VkDeviceMemory                        memory;
        VkExternalMemoryHandleTypeFlagBits    handleType;
    } VkMemoryGetWin32HandleInfoKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memory` is the memory object from which the handle will be exported.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the type of handle requested.

The properties of the handle returned depend on the value of `handleType`. See VkExternalMemoryHandleTypeFlagBits for a description of the properties of the defined external memory handle types.

Valid Usage

- VUID-VkMemoryGetWin32HandleInfoKHR-handleType-00662
  `handleType` must have been included in VkExportMemoryAllocateInfo::`handleTypes` when `memory` was created

- VUID-VkMemoryGetWin32HandleInfoKHR-handleType-00663
  If `handleType` is defined as an NT handle, vkGetMemoryWin32HandleKHR must be called no more than once for each valid unique combination of `memory` and `handleType`

- VUID-VkMemoryGetWin32HandleInfoKHR-handleType-00664
  `handleType` must be defined as an NT handle or a global share handle

Valid Usage (Implicit)

- VUID-VkMemoryGetWin32HandleInfoKHR-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_GET_WIN32_HANDLE_INFO_KHR`

- VUID-VkMemoryGetWin32HandleInfoKHR-pNext-pNext
  `pNext` must be `NULL`

- VUID-VkMemoryGetWin32HandleInfoKHR-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

- VUID-VkMemoryGetWin32HandleInfoKHR-handleType-parameter
  `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

Windows memory handles compatible with Vulkan may also be created by non-Vulkan APIs using methods beyond the scope of this specification. To determine the correct parameters to use when importing such handles, call:

    // Provided by VK_KHR_external_memory_win32
    VkResult vkGetMemoryWin32HandlePropertiesKHR(
        VkDevice                                    device,
        VkExternalMemoryHandleTypeFlagBits          handleType,
        HANDLE                                      handle,
        VkMemoryWin32HandlePropertiesKHR*           pMemoryWin32HandleProperties);

- `device` is the logical device that will be importing `handle`.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the type of the handle `handle`.

- `handle` is the handle which will be imported.

- `pMemoryWin32HandleProperties` is a pointer to a VkMemoryWin32HandlePropertiesKHR structure in which properties of `handle` are returned.

Valid Usage

- VUID-vkGetMemoryWin32HandlePropertiesKHR-handle-00665
  `handle` must be an external memory handle created outside of the Vulkan API

- VUID-vkGetMemoryWin32HandlePropertiesKHR-handleType-00666
  `handleType` must not be one of the handle types defined as opaque

Valid Usage (Implicit)

- VUID-vkGetMemoryWin32HandlePropertiesKHR-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryWin32HandlePropertiesKHR-handleType-parameter
  `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

- VUID-vkGetMemoryWin32HandlePropertiesKHR-pMemoryWin32HandleProperties-parameter
  `pMemoryWin32HandleProperties` must be a valid pointer to a VkMemoryWin32HandlePropertiesKHR structure

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_INVALID_EXTERNAL_HANDLE`

The `VkMemoryWin32HandlePropertiesKHR` structure returned is defined as:

    // Provided by VK_KHR_external_memory_win32
    typedef struct VkMemoryWin32HandlePropertiesKHR {
        VkStructureType    sType;
        void*              pNext;
        uint32_t           memoryTypeBits;
    } VkMemoryWin32HandlePropertiesKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memoryTypeBits` is a bitmask containing one bit set for every memory type which the specified windows handle can be imported as.

Valid Usage (Implicit)

- VUID-VkMemoryWin32HandlePropertiesKHR-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_WIN32_HANDLE_PROPERTIES_KHR`

- VUID-VkMemoryWin32HandlePropertiesKHR-pNext-pNext
  `pNext` must be `NULL`

When VkExportMemoryAllocateInfoNV::`handleTypes` includes `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT_NV`, add a `VkExportMemoryWin32HandleInfoNV` structure to the `pNext` chain of the VkExportMemoryAllocateInfoNV structure to specify security attributes and access rights for the memory object’s external handle.

The `VkExportMemoryWin32HandleInfoNV` structure is defined as:

    // Provided by VK_NV_external_memory_win32
    typedef struct VkExportMemoryWin32HandleInfoNV {
        VkStructureType               sType;
        const void*                   pNext;
        const SECURITY_ATTRIBUTES*    pAttributes;
        DWORD                         dwAccess;
    } VkExportMemoryWin32HandleInfoNV;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `pAttributes` is a pointer to a Windows `SECURITY_ATTRIBUTES` structure specifying security attributes of the handle.

- `dwAccess` is a `DWORD` specifying access rights of the handle.

If this structure is not present, or if `pAttributes` is set to `NULL`, default security descriptor values will be used, and child processes created by the application will not inherit the handle, as described in the MSDN documentation for “Synchronization Object Security and Access Rights”1. Further, if the structure is not present, the access rights will be

`DXGI_SHARED_RESOURCE_READ` | `DXGI_SHARED_RESOURCE_WRITE`

1

  https://docs.microsoft.com/en-us/windows/win32/sync/synchronization-object-security-and-access-rights

Valid Usage (Implicit)

- VUID-VkExportMemoryWin32HandleInfoNV-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_MEMORY_WIN32_HANDLE_INFO_NV`

- VUID-VkExportMemoryWin32HandleInfoNV-pAttributes-parameter
  If `pAttributes` is not `NULL`, `pAttributes` must be a valid pointer to a valid `SECURITY_ATTRIBUTES` value

To import memory created on the same physical device but outside of the current Vulkan instance, add a VkImportMemoryWin32HandleInfoNV structure to the `pNext` chain of the VkMemoryAllocateInfo structure, specifying a handle to and the type of the memory.

The `VkImportMemoryWin32HandleInfoNV` structure is defined as:

    // Provided by VK_NV_external_memory_win32
    typedef struct VkImportMemoryWin32HandleInfoNV {
        VkStructureType                      sType;
        const void*                          pNext;
        VkExternalMemoryHandleTypeFlagsNV    handleType;
        HANDLE                               handle;
    } VkImportMemoryWin32HandleInfoNV;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `handleType` is `0` or a VkExternalMemoryHandleTypeFlagBitsNV value specifying the type of memory handle in `handle`.

- `handle` is a Windows `HANDLE` referring to the memory.

If `handleType` is `0`, this structure is ignored by consumers of the VkMemoryAllocateInfo structure it is chained from.

Valid Usage

- VUID-VkImportMemoryWin32HandleInfoNV-handleType-01327
  `handleType` must not have more than one bit set

- VUID-VkImportMemoryWin32HandleInfoNV-handle-01328
  `handle` must be a valid handle to memory, obtained as specified by `handleType`

Valid Usage (Implicit)

- VUID-VkImportMemoryWin32HandleInfoNV-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_IMPORT_MEMORY_WIN32_HANDLE_INFO_NV`

- VUID-VkImportMemoryWin32HandleInfoNV-handleType-parameter
  `handleType` must be a valid combination of VkExternalMemoryHandleTypeFlagBitsNV values

Bits which can be set in `handleType` are:

Possible values of VkImportMemoryWin32HandleInfoNV::`handleType`, specifying the type of an external memory handle, are:

    // Provided by VK_NV_external_memory_capabilities
    typedef enum VkExternalMemoryHandleTypeFlagBitsNV {
        VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT_NV = 0x00000001,
        VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_KMT_BIT_NV = 0x00000002,
        VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_IMAGE_BIT_NV = 0x00000004,
        VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_IMAGE_KMT_BIT_NV = 0x00000008,
    } VkExternalMemoryHandleTypeFlagBitsNV;

- `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_KMT_BIT_NV` specifies a handle to memory returned by vkGetMemoryWin32HandleNV.

- `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT_NV` specifies a handle to memory returned by vkGetMemoryWin32HandleNV, or one duplicated from such a handle using `DuplicateHandle()`.

- `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_IMAGE_BIT_NV` specifies a valid NT handle to memory returned by `IDXGIResource1::CreateSharedHandle`, or a handle duplicated from such a handle using `DuplicateHandle()`.

- `VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_IMAGE_KMT_BIT_NV` specifies a handle to memory returned by `IDXGIResource::GetSharedHandle()`.

| editing-note (Jon) If additional (non-Win32) bits are added to the possible memory types, this type should move to the `VK_NV_external_memory_capabilities` section, and each bit would then be protected by ifdefs for the extension it is defined by.

    // Provided by VK_NV_external_memory_capabilities
    typedef VkFlags VkExternalMemoryHandleTypeFlagsNV;

`VkExternalMemoryHandleTypeFlagsNV` is a bitmask type for setting a mask of zero or more VkExternalMemoryHandleTypeFlagBitsNV.

To retrieve the handle corresponding to a device memory object created with VkExportMemoryAllocateInfoNV::`handleTypes` set to include `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT_NV` or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_KMT_BIT_NV`, call:

    // Provided by VK_NV_external_memory_win32
    VkResult vkGetMemoryWin32HandleNV(
        VkDevice                                    device,
        VkDeviceMemory                              memory,
        VkExternalMemoryHandleTypeFlagsNV           handleType,
        HANDLE*                                     pHandle);

- `device` is the logical device that owns the memory.

- `memory` is the VkDeviceMemory object.

- `handleType` is a bitmask of VkExternalMemoryHandleTypeFlagBitsNV containing a single bit specifying the type of handle requested.

- `handle` is a pointer to a Windows `HANDLE` in which the handle is returned.

Valid Usage

- VUID-vkGetMemoryWin32HandleNV-handleType-01326
  `handleType` must be a flag specified in VkExportMemoryAllocateInfoNV::`handleTypes` when allocating `memory`

Valid Usage (Implicit)

- VUID-vkGetMemoryWin32HandleNV-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryWin32HandleNV-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

- VUID-vkGetMemoryWin32HandleNV-handleType-parameter
  `handleType` must be a valid combination of VkExternalMemoryHandleTypeFlagBitsNV values

- VUID-vkGetMemoryWin32HandleNV-handleType-requiredbitmask
  `handleType` must not be `0`

- VUID-vkGetMemoryWin32HandleNV-pHandle-parameter
  `pHandle` must be a valid pointer to a `HANDLE` value

- VUID-vkGetMemoryWin32HandleNV-memory-parent
  `memory` must have been created, allocated, or retrieved from `device`

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_TOO_MANY_OBJECTS`

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

#### 11.2.5. File Descriptor External Memory

To import memory from a POSIX file descriptor handle, add a VkImportMemoryFdInfoKHR structure to the `pNext` chain of the VkMemoryAllocateInfo structure. The `VkImportMemoryFdInfoKHR` structure is defined as:

    // Provided by VK_KHR_external_memory_fd
    typedef struct VkImportMemoryFdInfoKHR {
        VkStructureType                       sType;
        const void*                           pNext;
        VkExternalMemoryHandleTypeFlagBits    handleType;
        int                                   fd;
    } VkImportMemoryFdInfoKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the handle type of `fd`.

- `fd` is the external handle to import.

Importing memory from a file descriptor transfers ownership of the file descriptor from the application to the Vulkan implementation. The application must not perform any operations on the file descriptor after a successful import. The imported memory object holds a reference to its payload.

Applications can import the same payload into multiple instances of Vulkan, into the same instance from which it was exported, and multiple times into a given Vulkan instance. In all cases, each import operation must create a distinct `VkDeviceMemory` object.

Valid Usage

- VUID-VkImportMemoryFdInfoKHR-handleType-00667
  If `handleType` is not `0`, it must be supported for import, as reported by VkExternalImageFormatProperties or VkExternalBufferProperties

- VUID-VkImportMemoryFdInfoKHR-fd-00668
  The memory from which `fd` was exported must have been created on the same underlying physical device as `device`

- VUID-VkImportMemoryFdInfoKHR-handleType-00669
  If `handleType` is not `0`, it must be `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT` or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_DMA_BUF_BIT_EXT`

- VUID-VkImportMemoryFdInfoKHR-handleType-00670
  If `handleType` is not `0`, `fd` must be a valid handle of the type specified by `handleType`

- VUID-VkImportMemoryFdInfoKHR-fd-01746
  The memory represented by `fd` must have been created from a physical device and driver that is compatible with `device` and `handleType`, as described in External memory handle types compatibility

- VUID-VkImportMemoryFdInfoKHR-fd-01520
  `fd` must obey any requirements listed for `handleType` in external memory handle types compatibility

Valid Usage (Implicit)

- VUID-VkImportMemoryFdInfoKHR-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_IMPORT_MEMORY_FD_INFO_KHR`

- VUID-VkImportMemoryFdInfoKHR-handleType-parameter
  If `handleType` is not `0`, `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

To export a POSIX file descriptor referencing the payload of a Vulkan device memory object, call:

    // Provided by VK_KHR_external_memory_fd
    VkResult vkGetMemoryFdKHR(
        VkDevice                                    device,
        const VkMemoryGetFdInfoKHR*                 pGetFdInfo,
        int*                                        pFd);

- `device` is the logical device that created the device memory being exported.

- `pGetFdInfo` is a pointer to a VkMemoryGetFdInfoKHR structure containing parameters of the export operation.

- `pFd` will return a file descriptor referencing the payload of the device memory object.

Each call to `vkGetMemoryFdKHR` must create a new file descriptor holding a reference to the memory object’s payload and transfer ownership of the file descriptor to the application. To avoid leaking resources, the application must release ownership of the file descriptor using the `close` system call when it is no longer needed, or by importing a Vulkan memory object from it. Where supported by the operating system, the implementation must set the file descriptor to be closed automatically when an `execve` system call is made.

Valid Usage (Implicit)

- VUID-vkGetMemoryFdKHR-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryFdKHR-pGetFdInfo-parameter
  `pGetFdInfo` must be a valid pointer to a valid VkMemoryGetFdInfoKHR structure

- VUID-vkGetMemoryFdKHR-pFd-parameter
  `pFd` must be a valid pointer to an `int` value

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_TOO_MANY_OBJECTS`

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

The `VkMemoryGetFdInfoKHR` structure is defined as:

    // Provided by VK_KHR_external_memory_fd
    typedef struct VkMemoryGetFdInfoKHR {
        VkStructureType                       sType;
        const void*                           pNext;
        VkDeviceMemory                        memory;
        VkExternalMemoryHandleTypeFlagBits    handleType;
    } VkMemoryGetFdInfoKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memory` is the memory object from which the handle will be exported.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the type of handle requested.

The properties of the file descriptor exported depend on the value of `handleType`. See VkExternalMemoryHandleTypeFlagBits for a description of the properties of the defined external memory handle types.

| Note The size of the exported file may be larger than the size requested by VkMemoryAllocateInfo::`allocationSize`. If `handleType` is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_DMA_BUF_BIT_EXT`, then the application can query the file’s actual size with `lseek`.

Valid Usage

- VUID-VkMemoryGetFdInfoKHR-handleType-00671
  `handleType` must have been included in VkExportMemoryAllocateInfo::`handleTypes` when `memory` was created

- VUID-VkMemoryGetFdInfoKHR-handleType-00672
  `handleType` must be `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT` or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_DMA_BUF_BIT_EXT`

Valid Usage (Implicit)

- VUID-VkMemoryGetFdInfoKHR-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_GET_FD_INFO_KHR`

- VUID-VkMemoryGetFdInfoKHR-pNext-pNext
  `pNext` must be `NULL`

- VUID-VkMemoryGetFdInfoKHR-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

- VUID-VkMemoryGetFdInfoKHR-handleType-parameter
  `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

POSIX file descriptor memory handles compatible with Vulkan may also be created by non-Vulkan APIs using methods beyond the scope of this specification. To determine the correct parameters to use when importing such handles, call:

    // Provided by VK_KHR_external_memory_fd
    VkResult vkGetMemoryFdPropertiesKHR(
        VkDevice                                    device,
        VkExternalMemoryHandleTypeFlagBits          handleType,
        int                                         fd,
        VkMemoryFdPropertiesKHR*                    pMemoryFdProperties);

- `device` is the logical device that will be importing `fd`.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the type of the handle `fd`.

- `fd` is the handle which will be imported.

- `pMemoryFdProperties` is a pointer to a VkMemoryFdPropertiesKHR structure in which the properties of the handle `fd` are returned.

Valid Usage

- VUID-vkGetMemoryFdPropertiesKHR-fd-00673
  `fd` must be an external memory handle created outside of the Vulkan API

- VUID-vkGetMemoryFdPropertiesKHR-handleType-00674
  `handleType` must not be `VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT`

Valid Usage (Implicit)

- VUID-vkGetMemoryFdPropertiesKHR-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryFdPropertiesKHR-handleType-parameter
  `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

- VUID-vkGetMemoryFdPropertiesKHR-pMemoryFdProperties-parameter
  `pMemoryFdProperties` must be a valid pointer to a VkMemoryFdPropertiesKHR structure

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_INVALID_EXTERNAL_HANDLE`

The `VkMemoryFdPropertiesKHR` structure returned is defined as:

    // Provided by VK_KHR_external_memory_fd
    typedef struct VkMemoryFdPropertiesKHR {
        VkStructureType    sType;
        void*              pNext;
        uint32_t           memoryTypeBits;
    } VkMemoryFdPropertiesKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memoryTypeBits` is a bitmask containing one bit set for every memory type which the specified file descriptor can be imported as.

Valid Usage (Implicit)

- VUID-VkMemoryFdPropertiesKHR-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_FD_PROPERTIES_KHR`

- VUID-VkMemoryFdPropertiesKHR-pNext-pNext
  `pNext` must be `NULL`

#### 11.2.6. Host External Memory

To import memory from a host pointer, add a VkImportMemoryHostPointerInfoEXT structure to the `pNext` chain of the VkMemoryAllocateInfo structure. The `VkImportMemoryHostPointerInfoEXT` structure is defined as:

    // Provided by VK_EXT_external_memory_host
    typedef struct VkImportMemoryHostPointerInfoEXT {
        VkStructureType                       sType;
        const void*                           pNext;
        VkExternalMemoryHandleTypeFlagBits    handleType;
        void*                                 pHostPointer;
    } VkImportMemoryHostPointerInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the handle type.

- `pHostPointer` is the host pointer to import from.

Importing memory from a host pointer shares ownership of the memory between the host and the Vulkan implementation. The application can continue to access the memory through the host pointer but it is the application’s responsibility to synchronize device and non-device access to the payload as defined in Host Access to Device Memory Objects.

Applications can import the same payload into multiple instances of Vulkan and multiple times into a given Vulkan instance. However, implementations may fail to import the same payload multiple times into a given physical device due to platform constraints.

Importing memory from a particular host pointer may not be possible due to additional platform-specific restrictions beyond the scope of this specification in which case the implementation must fail the memory import operation with the error code `VK_ERROR_INVALID_EXTERNAL_HANDLE_KHR`.

Whether device memory objects imported from a host pointer hold a reference to their payload is undefined. As such, the application must ensure that the imported memory range remains valid and accessible for the lifetime of the imported memory object.

Valid Usage

- VUID-VkImportMemoryHostPointerInfoEXT-handleType-01747
  If `handleType` is not `0`, it must be supported for import, as reported in VkExternalMemoryProperties

- VUID-VkImportMemoryHostPointerInfoEXT-handleType-01748
  If `handleType` is not `0`, it must be `VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT` or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_MAPPED_FOREIGN_MEMORY_BIT_EXT`

- VUID-VkImportMemoryHostPointerInfoEXT-pHostPointer-01749
  `pHostPointer` must be a pointer aligned to an integer multiple of `VkPhysicalDeviceExternalMemoryHostPropertiesEXT`::`minImportedHostPointerAlignment`

- VUID-VkImportMemoryHostPointerInfoEXT-handleType-01750
  If `handleType` is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT`, `pHostPointer` must be a pointer to `allocationSize` number of bytes of host memory, where `allocationSize` is the member of the `VkMemoryAllocateInfo` structure this structure is chained to

- VUID-VkImportMemoryHostPointerInfoEXT-handleType-01751
  If `handleType` is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_MAPPED_FOREIGN_MEMORY_BIT_EXT`, `pHostPointer` must be a pointer to `allocationSize` number of bytes of host mapped foreign memory, where `allocationSize` is the member of the `VkMemoryAllocateInfo` structure this structure is chained to

Valid Usage (Implicit)

- VUID-VkImportMemoryHostPointerInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_IMPORT_MEMORY_HOST_POINTER_INFO_EXT`

- VUID-VkImportMemoryHostPointerInfoEXT-handleType-parameter
  `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

To determine the correct parameters to use when importing host pointers, call:

    // Provided by VK_EXT_external_memory_host
    VkResult vkGetMemoryHostPointerPropertiesEXT(
        VkDevice                                    device,
        VkExternalMemoryHandleTypeFlagBits          handleType,
        const void*                                 pHostPointer,
        VkMemoryHostPointerPropertiesEXT*           pMemoryHostPointerProperties);

- `device` is the logical device that will be importing `pHostPointer`.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the type of the handle `pHostPointer`.

- `pHostPointer` is the host pointer to import from.

- `pMemoryHostPointerProperties` is a pointer to a VkMemoryHostPointerPropertiesEXT structure in which the host pointer properties are returned.

Valid Usage

- VUID-vkGetMemoryHostPointerPropertiesEXT-handleType-01752
  `handleType` must be `VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT` or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_MAPPED_FOREIGN_MEMORY_BIT_EXT`

- VUID-vkGetMemoryHostPointerPropertiesEXT-pHostPointer-01753
  `pHostPointer` must be a pointer aligned to an integer multiple of `VkPhysicalDeviceExternalMemoryHostPropertiesEXT`::`minImportedHostPointerAlignment`

- VUID-vkGetMemoryHostPointerPropertiesEXT-handleType-01754
  If `handleType` is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT`, `pHostPointer` must be a pointer to host memory

- VUID-vkGetMemoryHostPointerPropertiesEXT-handleType-01755
  If `handleType` is `VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_MAPPED_FOREIGN_MEMORY_BIT_EXT`, `pHostPointer` must be a pointer to host mapped foreign memory

Valid Usage (Implicit)

- VUID-vkGetMemoryHostPointerPropertiesEXT-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryHostPointerPropertiesEXT-handleType-parameter
  `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

- VUID-vkGetMemoryHostPointerPropertiesEXT-pMemoryHostPointerProperties-parameter
  `pMemoryHostPointerProperties` must be a valid pointer to a VkMemoryHostPointerPropertiesEXT structure

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_INVALID_EXTERNAL_HANDLE`

The `VkMemoryHostPointerPropertiesEXT` structure is defined as:

    // Provided by VK_EXT_external_memory_host
    typedef struct VkMemoryHostPointerPropertiesEXT {
        VkStructureType    sType;
        void*              pNext;
        uint32_t           memoryTypeBits;
    } VkMemoryHostPointerPropertiesEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memoryTypeBits` is a bitmask containing one bit set for every memory type which the specified host pointer can be imported as.

The value returned by `memoryTypeBits` must only include bits that identify memory types which are host visible.

Valid Usage (Implicit)

- VUID-VkMemoryHostPointerPropertiesEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_HOST_POINTER_PROPERTIES_EXT`

- VUID-VkMemoryHostPointerPropertiesEXT-pNext-pNext
  `pNext` must be `NULL`

#### 11.2.7. Android Hardware Buffer External Memory

To import memory created outside of the current Vulkan instance from an Android hardware buffer, add a `VkImportAndroidHardwareBufferInfoANDROID` structure to the `pNext` chain of the VkMemoryAllocateInfo structure. The `VkImportAndroidHardwareBufferInfoANDROID` structure is defined as:

    // Provided by VK_ANDROID_external_memory_android_hardware_buffer
    typedef struct VkImportAndroidHardwareBufferInfoANDROID {
        VkStructureType            sType;
        const void*                pNext;
        struct AHardwareBuffer*    buffer;
    } VkImportAndroidHardwareBufferInfoANDROID;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `buffer` is the Android hardware buffer to import.

If the vkAllocateMemory command succeeds, the implementation must acquire a reference to the imported hardware buffer, which it must release when the device memory object is freed. If the command fails, the implementation must not retain a reference.

Valid Usage

- VUID-VkImportAndroidHardwareBufferInfoANDROID-buffer-01880
  If `buffer` is not `NULL`, Android hardware buffers must be supported for import, as reported by VkExternalImageFormatProperties or VkExternalBufferProperties

- VUID-VkImportAndroidHardwareBufferInfoANDROID-buffer-01881
  If `buffer` is not `NULL`, it must be a valid Android hardware buffer object with `AHardwareBuffer_Desc`::`usage` compatible with Vulkan as described in Android Hardware Buffers

Valid Usage (Implicit)

- VUID-VkImportAndroidHardwareBufferInfoANDROID-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_IMPORT_ANDROID_HARDWARE_BUFFER_INFO_ANDROID`

- VUID-VkImportAndroidHardwareBufferInfoANDROID-buffer-parameter
  `buffer` must be a valid pointer to an `AHardwareBuffer` value

To export an Android hardware buffer referencing the payload of a Vulkan device memory object, call:

    // Provided by VK_ANDROID_external_memory_android_hardware_buffer
    VkResult vkGetMemoryAndroidHardwareBufferANDROID(
        VkDevice                                    device,
        const VkMemoryGetAndroidHardwareBufferInfoANDROID* pInfo,
        struct AHardwareBuffer**                    pBuffer);

- `device` is the logical device that created the device memory being exported.

- `pInfo` is a pointer to a VkMemoryGetAndroidHardwareBufferInfoANDROID structure containing parameters of the export operation.

- `pBuffer` will return an Android hardware buffer referencing the payload of the device memory object.

Each call to `vkGetMemoryAndroidHardwareBufferANDROID` must return an Android hardware buffer with a new reference acquired in addition to the reference held by the VkDeviceMemory. To avoid leaking resources, the application must release the reference by calling `AHardwareBuffer_release` when it is no longer needed. When called with the same handle in VkMemoryGetAndroidHardwareBufferInfoANDROID::`memory`, `vkGetMemoryAndroidHardwareBufferANDROID` must return the same Android hardware buffer object. If the device memory was created by importing an Android hardware buffer, `vkGetMemoryAndroidHardwareBufferANDROID` must return that same Android hardware buffer object.

Valid Usage (Implicit)

- VUID-vkGetMemoryAndroidHardwareBufferANDROID-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryAndroidHardwareBufferANDROID-pInfo-parameter
  `pInfo` must be a valid pointer to a valid VkMemoryGetAndroidHardwareBufferInfoANDROID structure

- VUID-vkGetMemoryAndroidHardwareBufferANDROID-pBuffer-parameter
  `pBuffer` must be a valid pointer to a valid pointer to an `AHardwareBuffer` value

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_TOO_MANY_OBJECTS`

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

The `VkMemoryGetAndroidHardwareBufferInfoANDROID` structure is defined as:

    // Provided by VK_ANDROID_external_memory_android_hardware_buffer
    typedef struct VkMemoryGetAndroidHardwareBufferInfoANDROID {
        VkStructureType    sType;
        const void*        pNext;
        VkDeviceMemory     memory;
    } VkMemoryGetAndroidHardwareBufferInfoANDROID;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memory` is the memory object from which the Android hardware buffer will be exported.

Valid Usage

- VUID-VkMemoryGetAndroidHardwareBufferInfoANDROID-handleTypes-01882
  `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID` must have been included in VkExportMemoryAllocateInfo::`handleTypes` when `memory` was created

- VUID-VkMemoryGetAndroidHardwareBufferInfoANDROID-pNext-01883
  If the `pNext` chain of the VkMemoryAllocateInfo used to allocate `memory` included a VkMemoryDedicatedAllocateInfo with non-`NULL` `image` member, then that `image` must already be bound to `memory`

Valid Usage (Implicit)

- VUID-VkMemoryGetAndroidHardwareBufferInfoANDROID-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_GET_ANDROID_HARDWARE_BUFFER_INFO_ANDROID`

- VUID-VkMemoryGetAndroidHardwareBufferInfoANDROID-pNext-pNext
  `pNext` must be `NULL`

- VUID-VkMemoryGetAndroidHardwareBufferInfoANDROID-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

To determine the memory parameters to use when importing an Android hardware buffer, call:

    // Provided by VK_ANDROID_external_memory_android_hardware_buffer
    VkResult vkGetAndroidHardwareBufferPropertiesANDROID(
        VkDevice                                    device,
        const struct AHardwareBuffer*               buffer,
        VkAndroidHardwareBufferPropertiesANDROID*   pProperties);

- `device` is the logical device that will be importing `buffer`.

- `buffer` is the Android hardware buffer which will be imported.

- `pProperties` is a pointer to a VkAndroidHardwareBufferPropertiesANDROID structure in which the properties of `buffer` are returned.

Valid Usage

- VUID-vkGetAndroidHardwareBufferPropertiesANDROID-buffer-01884
  `buffer` must be a valid Android hardware buffer object with at least one of the `AHARDWAREBUFFER_USAGE_GPU_*` flags in its `AHardwareBuffer_Desc`::`usage`

Valid Usage (Implicit)

- VUID-vkGetAndroidHardwareBufferPropertiesANDROID-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetAndroidHardwareBufferPropertiesANDROID-buffer-parameter
  `buffer` must be a valid pointer to a valid `AHardwareBuffer` value

- VUID-vkGetAndroidHardwareBufferPropertiesANDROID-pProperties-parameter
  `pProperties` must be a valid pointer to a VkAndroidHardwareBufferPropertiesANDROID structure

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_INVALID_EXTERNAL_HANDLE_KHR`

The `VkAndroidHardwareBufferPropertiesANDROID` structure returned is defined as:

    // Provided by VK_ANDROID_external_memory_android_hardware_buffer
    typedef struct VkAndroidHardwareBufferPropertiesANDROID {
        VkStructureType    sType;
        void*              pNext;
        VkDeviceSize       allocationSize;
        uint32_t           memoryTypeBits;
    } VkAndroidHardwareBufferPropertiesANDROID;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `allocationSize` is the size of the external memory

- `memoryTypeBits` is a bitmask containing one bit set for every memory type which the specified Android hardware buffer can be imported as.

Valid Usage (Implicit)

- VUID-VkAndroidHardwareBufferPropertiesANDROID-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_ANDROID_HARDWARE_BUFFER_PROPERTIES_ANDROID`

- VUID-VkAndroidHardwareBufferPropertiesANDROID-pNext-pNext
  Each `pNext` member of any structure (including this one) in the `pNext` chain must be either `NULL` or a pointer to a valid instance of VkAndroidHardwareBufferFormatProperties2ANDROID or VkAndroidHardwareBufferFormatPropertiesANDROID

- VUID-VkAndroidHardwareBufferPropertiesANDROID-sType-unique
  The `sType` value of each struct in the `pNext` chain must be unique

To obtain format properties of an Android hardware buffer, include a `VkAndroidHardwareBufferFormatPropertiesANDROID` structure in the `pNext` chain of the VkAndroidHardwareBufferPropertiesANDROID structure passed to vkGetAndroidHardwareBufferPropertiesANDROID. This structure is defined as:

    // Provided by VK_ANDROID_external_memory_android_hardware_buffer
    typedef struct VkAndroidHardwareBufferFormatPropertiesANDROID {
        VkStructureType                  sType;
        void*                            pNext;
        VkFormat                         format;
        uint64_t                         externalFormat;
        VkFormatFeatureFlags             formatFeatures;
        VkComponentMapping               samplerYcbcrConversionComponents;
        VkSamplerYcbcrModelConversion    suggestedYcbcrModel;
        VkSamplerYcbcrRange              suggestedYcbcrRange;
        VkChromaLocation                 suggestedXChromaOffset;
        VkChromaLocation                 suggestedYChromaOffset;
    } VkAndroidHardwareBufferFormatPropertiesANDROID;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `format` is the Vulkan format corresponding to the Android hardware buffer’s format, or `VK_FORMAT_UNDEFINED` if there is not an equivalent Vulkan format.

- `externalFormat` is an implementation-defined external format identifier for use with VkExternalFormatANDROID. It must not be zero.

- `formatFeatures` describes the capabilities of this external format when used with an image bound to memory imported from `buffer`.

- `samplerYcbcrConversionComponents` is the component swizzle that should be used in VkSamplerYcbcrConversionCreateInfo.

- `suggestedYcbcrModel` is a suggested color model to use in the VkSamplerYcbcrConversionCreateInfo.

- `suggestedYcbcrRange` is a suggested numerical value range to use in VkSamplerYcbcrConversionCreateInfo.

- `suggestedXChromaOffset` is a suggested X chroma offset to use in VkSamplerYcbcrConversionCreateInfo.

- `suggestedYChromaOffset` is a suggested Y chroma offset to use in VkSamplerYcbcrConversionCreateInfo.

If the Android hardware buffer has one of the formats listed in the Format Equivalence table, then `format` must have the equivalent Vulkan format listed in the table. Otherwise, `format` may be `VK_FORMAT_UNDEFINED`, indicating the Android hardware buffer can only be used with an external format.

The `formatFeatures` member must include `VK_FORMAT_FEATURE_SAMPLED_IMAGE_BIT` and at least one of `VK_FORMAT_FEATURE_MIDPOINT_CHROMA_SAMPLES_BIT` or `VK_FORMAT_FEATURE_COSITED_CHROMA_SAMPLES_BIT`, and should include `VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT` and `VK_FORMAT_FEATURE_SAMPLED_IMAGE_YCBCR_CONVERSION_LINEAR_FILTER_BIT`.

| Note The `formatFeatures` member only indicates the features available when using an external-format image created from the Android hardware buffer. Images from Android hardware buffers with a format other than `VK_FORMAT_UNDEFINED` are subject to the format capabilities obtained from vkGetPhysicalDeviceFormatProperties2, and vkGetPhysicalDeviceImageFormatProperties2 with appropriate parameters. These sets of features are independent of each other, e.g. the external format will support sampler Y′CBCR conversion even if the non-external format does not, and writing to non-external format images is possible but writing to external format images is not.

Android hardware buffers with the same external format must have the same support for `VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT`, `VK_FORMAT_FEATURE_MIDPOINT_CHROMA_SAMPLES_BIT`, `VK_FORMAT_FEATURE_COSITED_CHROMA_SAMPLES_BIT`, `VK_FORMAT_FEATURE_SAMPLED_IMAGE_YCBCR_CONVERSION_LINEAR_FILTER_BIT`, `VK_FORMAT_FEATURE_SAMPLED_IMAGE_YCBCR_CONVERSION_SEPARATE_RECONSTRUCTION_FILTER_BIT`, and `VK_FORMAT_FEATURE_SAMPLED_IMAGE_YCBCR_CONVERSION_CHROMA_RECONSTRUCTION_EXPLICIT_FORCEABLE_BIT`. in `formatFeatures`. Other format features may differ between Android hardware buffers that have the same external format. This allows applications to use the same VkSamplerYcbcrConversion object (and samplers and pipelines created from them) for any Android hardware buffers that have the same external format.

If `format` is not `VK_FORMAT_UNDEFINED`, then the value of `samplerYcbcrConversionComponents` must be valid when used as the `components` member of VkSamplerYcbcrConversionCreateInfo with that format. If `format` is `VK_FORMAT_UNDEFINED`, all members of `samplerYcbcrConversionComponents` must be the identity swizzle.

Implementations may not always be able to determine the color model, numerical range, or chroma offsets of the image contents, so the values in `VkAndroidHardwareBufferFormatPropertiesANDROID` are only suggestions. Applications should treat these values as sensible defaults to use in the absence of more reliable information obtained through some other means. If the underlying physical device is also usable via OpenGL ES with the `GL_OES_EGL_image_external` extension, the implementation should suggest values that will produce similar sampled values as would be obtained by sampling the same external image via `samplerExternalOES` in OpenGL ES using equivalent sampler parameters.

| Note Since `GL_OES_EGL_image_external` does not require the same sampling and conversion calculations as Vulkan does, achieving identical results between APIs may not be possible on some implementations.

Valid Usage (Implicit)

- VUID-VkAndroidHardwareBufferFormatPropertiesANDROID-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_ANDROID_HARDWARE_BUFFER_FORMAT_PROPERTIES_ANDROID`

The format properties of an Android hardware buffer can be obtained by including a `VkAndroidHardwareBufferFormatProperties2ANDROID` structure in the `pNext` chain of the VkAndroidHardwareBufferPropertiesANDROID structure passed to vkGetAndroidHardwareBufferPropertiesANDROID. This structure is defined as:

    // Provided by VK_KHR_format_feature_flags2 with VK_ANDROID_external_memory_android_hardware_buffer
    typedef struct VkAndroidHardwareBufferFormatProperties2ANDROID {
        VkStructureType                  sType;
        void*                            pNext;
        VkFormat                         format;
        uint64_t                         externalFormat;
        VkFormatFeatureFlags2            formatFeatures;
        VkComponentMapping               samplerYcbcrConversionComponents;
        VkSamplerYcbcrModelConversion    suggestedYcbcrModel;
        VkSamplerYcbcrRange              suggestedYcbcrRange;
        VkChromaLocation                 suggestedXChromaOffset;
        VkChromaLocation                 suggestedYChromaOffset;
    } VkAndroidHardwareBufferFormatProperties2ANDROID;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `format` is the Vulkan format corresponding to the Android hardware buffer’s format, or `VK_FORMAT_UNDEFINED` if there is not an equivalent Vulkan format.

- `externalFormat` is an implementation-defined external format identifier for use with VkExternalFormatANDROID. It must not be zero.

- `formatFeatures` describes the capabilities of this external format when used with an image bound to memory imported from `buffer`.

- `samplerYcbcrConversionComponents` is the component swizzle that should be used in VkSamplerYcbcrConversionCreateInfo.

- `suggestedYcbcrModel` is a suggested color model to use in the VkSamplerYcbcrConversionCreateInfo.

- `suggestedYcbcrRange` is a suggested numerical value range to use in VkSamplerYcbcrConversionCreateInfo.

- `suggestedXChromaOffset` is a suggested X chroma offset to use in VkSamplerYcbcrConversionCreateInfo.

- `suggestedYChromaOffset` is a suggested Y chroma offset to use in VkSamplerYcbcrConversionCreateInfo.

The bits reported in `formatFeatures` must include the bits reported in the corresponding fields of `VkAndroidHardwareBufferFormatPropertiesANDROID`::`formatFeatures`.

Valid Usage (Implicit)

- VUID-VkAndroidHardwareBufferFormatProperties2ANDROID-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_ANDROID_HARDWARE_BUFFER_FORMAT_PROPERTIES_2_ANDROID`

#### 11.2.8. Remote Device External Memory

To export an address representing the payload of a Vulkan device memory object accessible by remote devices, call:

    // Provided by VK_NV_external_memory_rdma
    VkResult vkGetMemoryRemoteAddressNV(
        VkDevice                                    device,
        const VkMemoryGetRemoteAddressInfoNV*       pMemoryGetRemoteAddressInfo,
        VkRemoteAddressNV*                          pAddress);

- `device` is the logical device that created the device memory being exported.

- `pMemoryGetRemoteAddressInfo` is a pointer to a VkMemoryGetRemoteAddressInfoNV structure containing parameters of the export operation.

- `pAddress` will return the address representing the payload of the device memory object.

More communication may be required between the kernel-mode drivers of the devices involved. This information is out of scope of this documentation and should be requested from the vendors of the devices.

Valid Usage (Implicit)

- VUID-vkGetMemoryRemoteAddressNV-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryRemoteAddressNV-pMemoryGetRemoteAddressInfo-parameter
  `pMemoryGetRemoteAddressInfo` must be a valid pointer to a valid VkMemoryGetRemoteAddressInfoNV structure

- VUID-vkGetMemoryRemoteAddressNV-pAddress-parameter
  `pAddress` must be a valid pointer to a `VkRemoteAddressNV` value

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_INVALID_EXTERNAL_HANDLE`

The `VkMemoryGetRemoteAddressInfoNV` structure is defined as:

    // Provided by VK_NV_external_memory_rdma
    typedef struct VkMemoryGetRemoteAddressInfoNV {
        VkStructureType                       sType;
        const void*                           pNext;
        VkDeviceMemory                        memory;
        VkExternalMemoryHandleTypeFlagBits    handleType;
    } VkMemoryGetRemoteAddressInfoNV;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memory` is the memory object from which the remote accessible address will be exported.

- `handleType` is the type of handle requested.

Valid Usage

- VUID-VkMemoryGetRemoteAddressInfoNV-handleType-04966
  `handleType` must have been included in VkExportMemoryAllocateInfo::`handleTypes` when `memory` was created

Valid Usage (Implicit)

- VUID-VkMemoryGetRemoteAddressInfoNV-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_GET_REMOTE_ADDRESS_INFO_NV`

- VUID-VkMemoryGetRemoteAddressInfoNV-pNext-pNext
  `pNext` must be `NULL`

- VUID-VkMemoryGetRemoteAddressInfoNV-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

- VUID-VkMemoryGetRemoteAddressInfoNV-handleType-parameter
  `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

#### 11.2.9. Fuchsia External Memory

On Fuchsia, when allocating memory that may be imported from another device, process or Vulkan instance, add a VkImportMemoryZirconHandleInfoFUCHSIA structure to the `pNext` chain of the VkMemoryAllocateInfo structure.

External memory on Fuchsia is imported and exported using VMO handles of type `zx_handle_t`. VMO handles to external memory are canonically obtained from Fuchsia’s Sysmem service or from syscalls such as `zx_vmo_create`(). VMO handles for import can also be obtained by exporting them from another Vulkan instance as described in exporting fuchsia device memory.

Importing VMO handles to the Vulkan instance transfers ownership of the handle to the instance from the application. The application must not perform any operations on the handle after successful import.

Applications can import the same underlying memory into multiple instances of Vulkan, into the same instance from which it was exported, and multiple times into a given Vulkan instance. In all cases, each import operation must create a distinct `VkDeviceMemory` object.

##### Importing Fuchsia External Memory

The `VkImportMemoryZirconHandleInfoFUCHSIA` structure is defined as:

    // Provided by VK_FUCHSIA_external_memory
    typedef struct VkImportMemoryZirconHandleInfoFUCHSIA {
        VkStructureType                       sType;
        const void*                           pNext;
        VkExternalMemoryHandleTypeFlagBits    handleType;
        zx_handle_t                           handle;
    } VkImportMemoryZirconHandleInfoFUCHSIA;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the type of `handle`.

- `handle` is a `zx_handle_t` (Zircon) handle to the external memory.

Valid Usage

- VUID-VkImportMemoryZirconHandleInfoFUCHSIA-handleType-04771
  `handleType` must be `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ZIRCON_VMO_BIT_FUCHSIA`

- VUID-VkImportMemoryZirconHandleInfoFUCHSIA-handle-04772
  `handle` must be a valid VMO handle

Valid Usage (Implicit)

- VUID-VkImportMemoryZirconHandleInfoFUCHSIA-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_IMPORT_MEMORY_ZIRCON_HANDLE_INFO_FUCHSIA`

- VUID-VkImportMemoryZirconHandleInfoFUCHSIA-handleType-parameter
  If `handleType` is not `0`, `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

To obtain the memoryTypeIndex for the VkMemoryAllocateInfo structure, call `vkGetMemoryZirconHandlePropertiesFUCHSIA`:

    // Provided by VK_FUCHSIA_external_memory
    VkResult vkGetMemoryZirconHandlePropertiesFUCHSIA(
        VkDevice                                    device,
        VkExternalMemoryHandleTypeFlagBits          handleType,
        zx_handle_t                                 zirconHandle,
        VkMemoryZirconHandlePropertiesFUCHSIA*      pMemoryZirconHandleProperties);

- `device` is the VkDevice.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the type of `zirconHandle`

- `zirconHandle` is a `zx_handle_t` (Zircon) handle to the external resource.

- `pMemoryZirconHandleProperties` is a pointer to a VkMemoryZirconHandlePropertiesFUCHSIA structure in which the result will be stored.

Valid Usage

- VUID-vkGetMemoryZirconHandlePropertiesFUCHSIA-handleType-04773
  `handleType` must be `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ZIRCON_VMO_BIT_FUCHSIA`

- VUID-vkGetMemoryZirconHandlePropertiesFUCHSIA-zirconHandle-04774
  `zirconHandle` must reference a valid VMO

Valid Usage (Implicit)

- VUID-vkGetMemoryZirconHandlePropertiesFUCHSIA-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryZirconHandlePropertiesFUCHSIA-handleType-parameter
  `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

- VUID-vkGetMemoryZirconHandlePropertiesFUCHSIA-pMemoryZirconHandleProperties-parameter
  `pMemoryZirconHandleProperties` must be a valid pointer to a VkMemoryZirconHandlePropertiesFUCHSIA structure

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_INVALID_EXTERNAL_HANDLE`

The `VkMemoryZirconHandlePropertiesFUCHSIA` structure is defined as:

    // Provided by VK_FUCHSIA_external_memory
    typedef struct VkMemoryZirconHandlePropertiesFUCHSIA {
        VkStructureType    sType;
        void*              pNext;
        uint32_t           memoryTypeBits;
    } VkMemoryZirconHandlePropertiesFUCHSIA;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memoryTypeBits` a bitmask containing one bit set for every memory type which the specified handle can be imported as.

Valid Usage (Implicit)

- VUID-VkMemoryZirconHandlePropertiesFUCHSIA-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_ZIRCON_HANDLE_PROPERTIES_FUCHSIA`

- VUID-VkMemoryZirconHandlePropertiesFUCHSIA-pNext-pNext
  `pNext` must be `NULL`

With `pMemoryZirconHandleProperties` now successfully populated by vkGetMemoryZirconHandlePropertiesFUCHSIA, assign the VkMemoryAllocateInfo memoryTypeIndex field to a memory type which has a bit set in the VkMemoryZirconHandlePropertiesFUCHSIA memoryTypeBits field.

##### Exporting Fuchsia Device Memory

Similar to importing, exporting a VMO handle from Vulkan transfers ownership of the handle from the Vulkan instance to the application. The application is responsible for closing the handle with `zx_handle_close`() when it is no longer in use.

To export device memory as a Zircon handle that can be used by another instance, device, or process, the handle to the VkDeviceMemory must be retrieved using vkGetMemoryZirconHandleFUCHSIA:

    // Provided by VK_FUCHSIA_external_memory
    VkResult vkGetMemoryZirconHandleFUCHSIA(
        VkDevice                                    device,
        const VkMemoryGetZirconHandleInfoFUCHSIA*   pGetZirconHandleInfo,
        zx_handle_t*                                pZirconHandle);

- `device` is the VkDevice.

- `pGetZirconHandleInfo` is a pointer to a VkMemoryGetZirconHandleInfoFUCHSIA structure.

- `pZirconHandle` is a pointer to a `zx_handle_t` which holds the resulting Zircon handle.

Valid Usage (Implicit)

- VUID-vkGetMemoryZirconHandleFUCHSIA-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryZirconHandleFUCHSIA-pGetZirconHandleInfo-parameter
  `pGetZirconHandleInfo` must be a valid pointer to a valid VkMemoryGetZirconHandleInfoFUCHSIA structure

- VUID-vkGetMemoryZirconHandleFUCHSIA-pZirconHandle-parameter
  `pZirconHandle` must be a valid pointer to a `zx_handle_t` value

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_TOO_MANY_OBJECTS`

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

`VkMemoryGetZirconHandleInfoFUCHSIA` is defined as:

    // Provided by VK_FUCHSIA_external_memory
    typedef struct VkMemoryGetZirconHandleInfoFUCHSIA {
        VkStructureType                       sType;
        const void*                           pNext;
        VkDeviceMemory                        memory;
        VkExternalMemoryHandleTypeFlagBits    handleType;
    } VkMemoryGetZirconHandleInfoFUCHSIA;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memory` the VkDeviceMemory being exported.

- `handleType` is a VkExternalMemoryHandleTypeFlagBits value specifying the type of the handle pointed to by vkGetMemoryZirconHandleFUCHSIA::`pZirconHandle`.

Valid Usage

- VUID-VkMemoryGetZirconHandleInfoFUCHSIA-handleType-04775
  `handleType` must be `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ZIRCON_VMO_BIT_FUCHSIA`

- VUID-VkMemoryGetZirconHandleInfoFUCHSIA-handleType-04776
  `handleType` must have been included in the `handleTypes` field of the `VkExportMemoryAllocateInfo` structure when the external memory was allocated

Valid Usage (Implicit)

- VUID-VkMemoryGetZirconHandleInfoFUCHSIA-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_GET_ZIRCON_HANDLE_INFO_FUCHSIA`

- VUID-VkMemoryGetZirconHandleInfoFUCHSIA-pNext-pNext
  `pNext` must be `NULL`

- VUID-VkMemoryGetZirconHandleInfoFUCHSIA-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

- VUID-VkMemoryGetZirconHandleInfoFUCHSIA-handleType-parameter
  `handleType` must be a valid VkExternalMemoryHandleTypeFlagBits value

With the result `pZirconHandle` now obtained, the memory properties for the handle can be retrieved using vkGetMemoryZirconHandlePropertiesFUCHSIA as documented above substituting the dereferenced, retrieved `pZirconHandle` in for the `zirconHandle` argument.

#### 11.2.10. Metal Objects

A Vulkan implementation that is layered on top of Metal on Apple device platform, and implements the `VK_EXT_metal_objects` extension, supports the ability to import and export the underlying Metal objects associated with specific Vulkan objects.

The underlying Metal objects associated with certain Vulkan objects can be exported from those Vulkan objects using the `pNext` chain of the VkExportMetalObjectsInfoEXT parameter of the vkExportMetalObjectsEXT command.

An VkDeviceMemory object can be allocated on an existing `MTLBuffer` object, by including the `MTLBuffer` object in a VkImportMetalBufferInfoEXT structure in the `pNext` chain of the VkMemoryAllocateInfo structure in the vkAllocateMemory command.

A new VkImage object can be created on an existing `IOSurface` object, or one or more existing Metal `MTLTexture` objects, by including those Metal objects in either VkImportMetalIOSurfaceInfoEXT or VkImportMetalTextureInfoEXT structures in the `pNext` chain of the VkImageCreateInfo structure in the vkCreateImage command.

To export Metal objects from Vulkan objects, the app must first indicate the intention to do so during the creation of the Vulkan object, by including one or more VkExportMetalObjectCreateInfoEXT structures in the `pNext` chain of the VkInstanceCreateInfo, VkMemoryAllocateInfo, VkImageCreateInfo, VkImageViewCreateInfo, VkBufferViewCreateInfo, VkSemaphoreCreateInfo, or VkEventCreateInfo, in the corresponding Vulkan object creation command.

The `VkExportMetalObjectCreateInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkExportMetalObjectCreateInfoEXT {
        VkStructureType                       sType;
        const void*                           pNext;
        VkExportMetalObjectTypeFlagBitsEXT    exportObjectType;
    } VkExportMetalObjectCreateInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `exportObjectType` is a VkExportMetalObjectTypeFlagBitsEXT indicating the type of Metal object that the application may request to be exported from the Vulkan object.

Valid Usage (Implicit)

- VUID-VkExportMetalObjectCreateInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_METAL_OBJECT_CREATE_INFO_EXT`

- VUID-VkExportMetalObjectCreateInfoEXT-exportObjectType-parameter
  If `exportObjectType` is not `0`, `exportObjectType` must be a valid VkExportMetalObjectTypeFlagBitsEXT value

Bits which indicate the types of Metal objects that may be exported from a corresponding Vulkan object are:

    // Provided by VK_EXT_metal_objects
    typedef enum VkExportMetalObjectTypeFlagBitsEXT {
        VK_EXPORT_METAL_OBJECT_TYPE_METAL_DEVICE_BIT_EXT = 0x00000001,
        VK_EXPORT_METAL_OBJECT_TYPE_METAL_COMMAND_QUEUE_BIT_EXT = 0x00000002,
        VK_EXPORT_METAL_OBJECT_TYPE_METAL_BUFFER_BIT_EXT = 0x00000004,
        VK_EXPORT_METAL_OBJECT_TYPE_METAL_TEXTURE_BIT_EXT = 0x00000008,
        VK_EXPORT_METAL_OBJECT_TYPE_METAL_IOSURFACE_BIT_EXT = 0x00000010,
        VK_EXPORT_METAL_OBJECT_TYPE_METAL_SHARED_EVENT_BIT_EXT = 0x00000020,
    } VkExportMetalObjectTypeFlagBitsEXT;

- `VK_EXPORT_METAL_OBJECT_TYPE_METAL_DEVICE_BIT_EXT` indicates a Metal `MTLDevice` may be exported.

- `VK_EXPORT_METAL_OBJECT_TYPE_METAL_COMMAND_QUEUE_BIT_EXT` indicates a Metal `MTLCommandQueue` may be exported.

- `VK_EXPORT_METAL_OBJECT_TYPE_METAL_BUFFER_BIT_EXT` indicates a Metal `MTLBuffer` may be exported.

- `VK_EXPORT_METAL_OBJECT_TYPE_METAL_TEXTURE_BIT_EXT` indicates a Metal `MTLTexture` may be exported.

- `VK_EXPORT_METAL_OBJECT_TYPE_METAL_IOSURFACE_BIT_EXT` indicates a Metal `IOSurface` may be exported.

- `VK_EXPORT_METAL_OBJECT_TYPE_METAL_SHARED_EVENT_BIT_EXT` indicates a Metal `MTLSharedEvent` may be exported.

    // Provided by VK_EXT_metal_objects
    typedef VkFlags VkExportMetalObjectTypeFlagsEXT;

`VkExportMetalObjectTypeFlagsEXT` is a bitmask type for setting a mask of zero or more VkExportMetalObjectTypeFlagBitsEXT.

To export Metal objects that underlie Vulkan objects, call:

    // Provided by VK_EXT_metal_objects
    void vkExportMetalObjectsEXT(
        VkDevice                                    device,
        VkExportMetalObjectsInfoEXT*                pMetalObjectsInfo);

- `device` is the device that created the Vulkan objects.

- `pMetalObjectsInfo` is a pointer to a VkExportMetalObjectsInfoEXT structure whose `pNext` chain contains structures, each identifying a Vulkan object and providing a pointer through which the Metal object will be returned.

Valid Usage (Implicit)

- VUID-vkExportMetalObjectsEXT-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkExportMetalObjectsEXT-pMetalObjectsInfo-parameter
  `pMetalObjectsInfo` must be a valid pointer to a VkExportMetalObjectsInfoEXT structure

The `VkExportMetalObjectsInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkExportMetalObjectsInfoEXT {
        VkStructureType    sType;
        const void*        pNext;
    } VkExportMetalObjectsInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

Valid Usage

- VUID-VkExportMetalObjectsInfoEXT-pNext-06791
  If the `pNext` chain includes a VkExportMetalDeviceInfoEXT structure, the VkInstance must have been created with `VK_EXPORT_METAL_OBJECT_TYPE_METAL_DEVICE_BIT_EXT` in the `exportObjectType` member of a VkExportMetalObjectCreateInfoEXT structure in the `pNext` chain of the VkInstanceCreateInfo structure in the vkCreateInstance command.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06792
  If the `pNext` chain includes a VkExportMetalCommandQueueInfoEXT structure, the VkInstance must have been created with `VK_EXPORT_METAL_OBJECT_TYPE_METAL_COMMAND_QUEUE_BIT_EXT` in the `exportObjectType` member of a VkExportMetalObjectCreateInfoEXT structure in the `pNext` chain of the VkInstanceCreateInfo structure in the vkCreateInstance command.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06793
  If the `pNext` chain includes a VkExportMetalBufferInfoEXT structure, the VkDeviceMemory in its `memory` member must have been allocated with `VK_EXPORT_METAL_OBJECT_TYPE_METAL_BUFFER_BIT_EXT` in the `exportObjectType` member of a VkExportMetalObjectCreateInfoEXT structure in the `pNext` chain of the VkMemoryAllocateInfo structure in the vkAllocateMemory command.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06794
  If the `pNext` chain includes a VkExportMetalTextureInfoEXT structure, exactly one of its `image`, `imageView`, or `bufferView` members must not be VK_NULL_HANDLE.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06795
  If the `pNext` chain includes a VkExportMetalTextureInfoEXT structure, and its `image` member is not `VK_NULL_HANDLE`, the VkImage in its `image` member must have been created with `VK_EXPORT_METAL_OBJECT_TYPE_METAL_TEXTURE_BIT_EXT` in the `exportObjectType` member of a VkExportMetalObjectCreateInfoEXT structure in the `pNext` chain of the VkImageCreateInfo structure in the vkCreateImage command.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06796
  If the `pNext` chain includes a VkExportMetalTextureInfoEXT structure, and its `imageView` member is not `VK_NULL_HANDLE`, the VkImageView in its `imageView` member must have been created with `VK_EXPORT_METAL_OBJECT_TYPE_METAL_TEXTURE_BIT_EXT` in the `exportObjectType` member of a VkExportMetalObjectCreateInfoEXT structure in the `pNext` chain of the VkImageViewCreateInfo structure in the vkCreateImageView command.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06797
  If the `pNext` chain includes a VkExportMetalTextureInfoEXT structure, and its `bufferView` member is not `VK_NULL_HANDLE`, the VkBufferView in its `bufferView` member must have been created with `VK_EXPORT_METAL_OBJECT_TYPE_METAL_TEXTURE_BIT_EXT` in the `exportObjectType` member of a VkExportMetalObjectCreateInfoEXT structure in the `pNext` chain of the VkBufferViewCreateInfo structure in the vkCreateBufferView command.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06798
  If the `pNext` chain includes a VkExportMetalTextureInfoEXT structure, and if either its `image` or `imageView` member is not VK_NULL_HANDLE, then `plane` must be `VK_IMAGE_ASPECT_PLANE_0_BIT`, `VK_IMAGE_ASPECT_PLANE_1_BIT`, or `VK_IMAGE_ASPECT_PLANE_2_BIT`.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06799
  If the `pNext` chain includes a VkExportMetalTextureInfoEXT structure, and if the VkImage in its `image` member does not have a multi-planar format, then its `plane` member must be `VK_IMAGE_ASPECT_PLANE_0_BIT`.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06800
  If the `pNext` chain includes a VkExportMetalTextureInfoEXT structure, and if the VkImage in its `image` member has a multi-planar format with only two planes, then its `plane` member must not be `VK_IMAGE_ASPECT_PLANE_2_BIT`

- VUID-VkExportMetalObjectsInfoEXT-pNext-06801
  If the `pNext` chain includes a VkExportMetalTextureInfoEXT structure, and if the VkImageView in its `imageView` member does not have a multi-planar format, then its `plane` member must be `VK_IMAGE_ASPECT_PLANE_0_BIT`.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06802
  If the `pNext` chain includes a VkExportMetalTextureInfoEXT structure, and if the VkImageView in its `imageView` member has a multi-planar format with only two planes, then its `plane` member must not be `VK_IMAGE_ASPECT_PLANE_2_BIT`

- VUID-VkExportMetalObjectsInfoEXT-pNext-06803
  If the `pNext` chain includes a VkExportMetalIOSurfaceInfoEXT structure, the VkImage in its `image` member must have been created with `VK_EXPORT_METAL_OBJECT_TYPE_METAL_IOSURFACE_BIT_EXT` in the `exportObjectType` member of a VkExportMetalObjectCreateInfoEXT structure in the `pNext` chain of the VkImageCreateInfo structure in the vkCreateImage command.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06804
  If the `pNext` chain includes a VkExportMetalSharedEventInfoEXT structure, exactly one of its `semaphore` or `event` members must not be VK_NULL_HANDLE.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06805
  If the `pNext` chain includes a VkExportMetalSharedEventInfoEXT structure, and its `semaphore` member is not `VK_NULL_HANDLE`, the VkSemaphore in its `semaphore` member must have been created with `VK_EXPORT_METAL_OBJECT_TYPE_METAL_SHARED_EVENT_BIT_EXT` in the `exportObjectType` member of a VkExportMetalObjectCreateInfoEXT structure in the `pNext` chain of the VkSemaphoreCreateInfo structure in the vkCreateSemaphore command.

- VUID-VkExportMetalObjectsInfoEXT-pNext-06806
  If the `pNext` chain includes a VkExportMetalSharedEventInfoEXT structure, and its `event` member is not `VK_NULL_HANDLE`, the VkEvent in its `event` member must have been created with `VK_EXPORT_METAL_OBJECT_TYPE_METAL_SHARED_EVENT_BIT_EXT` in the `exportObjectType` member of a VkExportMetalObjectCreateInfoEXT structure in the `pNext` chain of the VkEventCreateInfo structure in the vkCreateEvent command.

Valid Usage (Implicit)

- VUID-VkExportMetalObjectsInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_METAL_OBJECTS_INFO_EXT`

- VUID-VkExportMetalObjectsInfoEXT-pNext-pNext
  Each `pNext` member of any structure (including this one) in the `pNext` chain must be either `NULL` or a pointer to a valid instance of VkExportMetalBufferInfoEXT, VkExportMetalCommandQueueInfoEXT, VkExportMetalDeviceInfoEXT, VkExportMetalIOSurfaceInfoEXT, VkExportMetalSharedEventInfoEXT, or VkExportMetalTextureInfoEXT

- VUID-VkExportMetalObjectsInfoEXT-sType-unique
  The `sType` value of each struct in the `pNext` chain must be unique, with the exception of structures of type VkExportMetalBufferInfoEXT, VkExportMetalCommandQueueInfoEXT, VkExportMetalIOSurfaceInfoEXT, VkExportMetalSharedEventInfoEXT, or VkExportMetalTextureInfoEXT

To export the Metal `MTLDevice` object underlying the VkPhysicalDevice associated with a VkDevice object, include a `VkExportMetalDeviceInfoEXT` structure in the `pNext` chain of the `pMetalObjectsInfo` parameter of a vkExportMetalObjectsEXT call.

The `VkExportMetalDeviceInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkExportMetalDeviceInfoEXT {
        VkStructureType    sType;
        const void*        pNext;
        MTLDevice_id       mtlDevice;
    } VkExportMetalDeviceInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `mtlDevice` is the Metal `id<MTLDevice>` object underlying the VkPhysicalDevice associated with the VkDevice object identified in the call. The implementation will return the `MTLDevice` in this member, or it will return `NULL` if no `MTLDevice` could be found underlying the VkPhysicalDevice object.

Valid Usage (Implicit)

- VUID-VkExportMetalDeviceInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_METAL_DEVICE_INFO_EXT`

The type `id<MTLDevice>` is defined in Apple’s Metal framework, but to remove an unnecessary compile-time dependency, an incomplete type definition of `MTLDevice_id` is provided in the Vulkan headers:

    // Provided by VK_EXT_metal_objects
    #ifdef __OBJC__
    @protocol MTLDevice;
    typedef id<MTLDevice> MTLDevice_id;
    #else
    typedef void* MTLDevice_id;
    #endif

To export the Metal `MTLCommandQueue` object underlying a VkQueue object, include a `VkExportMetalCommandQueueInfoEXT` structure in the `pNext` chain of the `pMetalObjectsInfo` parameter of a vkExportMetalObjectsEXT call.

The `VkExportMetalCommandQueueInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkExportMetalCommandQueueInfoEXT {
        VkStructureType       sType;
        const void*           pNext;
        VkQueue               queue;
        MTLCommandQueue_id    mtlCommandQueue;
    } VkExportMetalCommandQueueInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `queue` is a VkQueue.

- `mtlCommandQueue` is the Metal `id<MTLCommandQueue>` object underlying the VkQueue object in `queue`. The implementation will return the `MTLCommandQueue` in this member, or it will return `NULL` if no `MTLCommandQueue` could be found underlying the VkQueue object.

Valid Usage (Implicit)

- VUID-VkExportMetalCommandQueueInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_METAL_COMMAND_QUEUE_INFO_EXT`

- VUID-VkExportMetalCommandQueueInfoEXT-queue-parameter
  `queue` must be a valid VkQueue handle

The type `id<MTLCommandQueue>` is defined in Apple’s Metal framework, but to remove an unnecessary compile-time dependency, an incomplete type definition of `MTLCommandQueue_id` is provided in the Vulkan headers:

    // Provided by VK_EXT_metal_objects
    #ifdef __OBJC__
    @protocol MTLCommandQueue;
    typedef id<MTLCommandQueue> MTLCommandQueue_id;
    #else
    typedef void* MTLCommandQueue_id;
    #endif

To export the Metal `MTLBuffer` object underlying a VkDeviceMemory object, include a `VkExportMetalBufferInfoEXT` structure in the `pNext` chain of the `pMetalObjectsInfo` parameter of a vkExportMetalObjectsEXT call.

The `VkExportMetalBufferInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkExportMetalBufferInfoEXT {
        VkStructureType    sType;
        const void*        pNext;
        VkDeviceMemory     memory;
        MTLBuffer_id       mtlBuffer;
    } VkExportMetalBufferInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memory` is a VkDeviceMemory.

- `mtlBuffer` is the Metal `id<MTLBuffer>` object underlying the VkDeviceMemory object in `memory`. The implementation will return the `MTLBuffer` in this member, or it will return `NULL` if no `MTLBuffer` could be found underlying the VkDeviceMemory object.

Valid Usage (Implicit)

- VUID-VkExportMetalBufferInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_METAL_BUFFER_INFO_EXT`

- VUID-VkExportMetalBufferInfoEXT-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

To import a Metal `MTLBuffer` object to underlie a VkDeviceMemory object, include a `VkImportMetalBufferInfoEXT` structure in the `pNext` chain of the VkMemoryAllocateInfo structure in a vkAllocateMemory command.

The `VkImportMetalBufferInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkImportMetalBufferInfoEXT {
        VkStructureType    sType;
        const void*        pNext;
        MTLBuffer_id       mtlBuffer;
    } VkImportMetalBufferInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `mtlBuffer` is the Metal `id<MTLBuffer>` object that is to underlie the VkDeviceMemory.

The app must ensure that the configuration of the `id<MTLBuffer>` object is compatible with the configuration of the VkDeviceMemory. Failure to do so results in undefined behavior.

Valid Usage (Implicit)

- VUID-VkImportMetalBufferInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_IMPORT_METAL_BUFFER_INFO_EXT`

The type `id<MTLBuffer>` is defined in Apple’s Metal framework, but to remove an unnecessary compile-time dependency, an incomplete type definition of `MTLBuffer_id` is provided in the Vulkan headers:

    // Provided by VK_EXT_metal_objects
    #ifdef __OBJC__
    @protocol MTLBuffer;
    typedef id<MTLBuffer> MTLBuffer_id;
    #else
    typedef void* MTLBuffer_id;
    #endif

To export a Metal `MTLTexture` object underlying a VkImage, VkImageView, or VkBufferView object, include a `VkExportMetalTextureInfoEXT` structure in the `pNext` chain of the `pMetalObjectsInfo` parameter of a vkExportMetalObjectsEXT call.

The `VkExportMetalTextureInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkExportMetalTextureInfoEXT {
        VkStructureType          sType;
        const void*              pNext;
        VkImage                  image;
        VkImageView              imageView;
        VkBufferView             bufferView;
        VkImageAspectFlagBits    plane;
        MTLTexture_id            mtlTexture;
    } VkExportMetalTextureInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `image` is `VK_NULL_HANDLE` or a VkImage.

- `imageView` is `VK_NULL_HANDLE` or a VkImageView.

- `bufferView` is `VK_NULL_HANDLE` or a VkBufferView.

- `plane` indicates the plane of a multi-planar VkImage or VkImageView.

- `mtlTexture` is the Metal `id<MTLTexture>` object underlying the VkImage, VkImageView, or VkBufferView object in `image`, `imageView`, or `bufferView`, respectively, at the plane indicated in `aspectMask`. The implementation will return the `MTLTexture` in this member, or it will return `NULL` if no `MTLTexture` could be found underlying the VkImage, VkImageView, or VkBufferView object, at the plane indicated in `aspectMask`.

Valid Usage (Implicit)

- VUID-VkExportMetalTextureInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_METAL_TEXTURE_INFO_EXT`

- VUID-VkExportMetalTextureInfoEXT-image-parameter
  If `image` is not VK_NULL_HANDLE, `image` must be a valid VkImage handle

- VUID-VkExportMetalTextureInfoEXT-imageView-parameter
  If `imageView` is not VK_NULL_HANDLE, `imageView` must be a valid VkImageView handle

- VUID-VkExportMetalTextureInfoEXT-bufferView-parameter
  If `bufferView` is not VK_NULL_HANDLE, `bufferView` must be a valid VkBufferView handle

- VUID-VkExportMetalTextureInfoEXT-plane-parameter
  `plane` must be a valid VkImageAspectFlagBits value

- VUID-VkExportMetalTextureInfoEXT-commonparent
  Each of `bufferView`, `image`, and `imageView` that are valid handles of non-ignored parameters must have been created, allocated, or retrieved from the same VkDevice

To import one or more existing Metal `MTLTexture` objects to underlie a VkImage object, include one or more `VkImportMetalTextureInfoEXT` structures in the `pNext` chain of the VkImageCreateInfo structure in a vkCreateImage command.

The `VkImportMetalTextureInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkImportMetalTextureInfoEXT {
        VkStructureType          sType;
        const void*              pNext;
        VkImageAspectFlagBits    plane;
        MTLTexture_id            mtlTexture;
    } VkImportMetalTextureInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `plane` indicates the plane of the VkImage that the `id<MTLTexture>` object should be attached to.

- `mtlTexture` is a the Metal `id<MTLTexture>` object that is to underlie the VkImage plane.

The `pNext` chain must include one `VkImportMetalTextureInfoEXT` structure for each plane in the VkImage. The app must ensure that the configuration of the Metal `id<MTLTexture>` objects are compatible with the configuration of the VkImage. Failure to do so results in undefined behavior.

Valid Usage (Implicit)

- VUID-VkImportMetalTextureInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_IMPORT_METAL_TEXTURE_INFO_EXT`

- VUID-VkImportMetalTextureInfoEXT-plane-parameter
  `plane` must be a valid VkImageAspectFlagBits value

The type `id<MTLTexture>` is defined in Apple’s Metal framework, but to remove an unnecessary compile-time dependency, an incomplete type definition of `MTLTexture_id` is provided in the Vulkan headers:

    // Provided by VK_EXT_metal_objects
    #ifdef __OBJC__
    @protocol MTLTexture;
    typedef id<MTLTexture> MTLTexture_id;
    #else
    typedef void* MTLTexture_id;
    #endif

To export the Metal `IOSurfaceRef` object underlying a VkImage object, include a `VkExportMetalIOSurfaceInfoEXT` structure in the `pNext` chain of the `pMetalObjectsInfo` parameter of a vkExportMetalObjectsEXT call.

The `VkExportMetalIOSurfaceInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkExportMetalIOSurfaceInfoEXT {
        VkStructureType    sType;
        const void*        pNext;
        VkImage            image;
        IOSurfaceRef       ioSurface;
    } VkExportMetalIOSurfaceInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `image` is a VkImage.

- `ioSurface` is the Metal `IOSurfaceRef` object underlying the VkImage object in `image`. The implementation will return the `IOSurfaceRef` in this member, or it will return `NULL` if no `IOSurfaceRef` could be found underlying the VkImage object.

Valid Usage (Implicit)

- VUID-VkExportMetalIOSurfaceInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_METAL_IO_SURFACE_INFO_EXT`

- VUID-VkExportMetalIOSurfaceInfoEXT-image-parameter
  `image` must be a valid VkImage handle

To import, or create, a Metal `IOSurfaceRef` object to underlie a VkImage object, include a `VkImportMetalIOSurfaceInfoEXT` structure in the `pNext` chain of the VkImageCreateInfo structure in a vkCreateImage command.

The `VkImportMetalIOSurfaceInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkImportMetalIOSurfaceInfoEXT {
        VkStructureType    sType;
        const void*        pNext;
        IOSurfaceRef       ioSurface;
    } VkImportMetalIOSurfaceInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `ioSurface` is `VK_NULL_HANDLE` or the Metal `IOSurfaceRef` object that is to underlie the VkImage.

If `ioSurface` is not `VK_NULL_HANDLE`, it will be used to underlie the VkImage. If `ioSurface` is `VK_NULL_HANDLE`, the implementation will create a new `IOSurface` to underlie the VkImage.

If provided, the app must ensure that the configuration of the `IOSurfaceRef` object is compatible with the configuration of the VkImage. Failure to do so results in undefined behavior.

Valid Usage (Implicit)

- VUID-VkImportMetalIOSurfaceInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_IMPORT_METAL_IO_SURFACE_INFO_EXT`

The type `IOSurfaceRef` is defined in Apple’s CoreGraphics framework, but to remove an unnecessary compile-time dependency, an incomplete type definition of `IOSurfaceRef` is provided in the Vulkan headers:

    // Provided by VK_EXT_metal_objects
    typedef struct __IOSurface* IOSurfaceRef;

To export the Metal `MTLSharedEvent` object underlying a VkSemaphore or VkEvent object, include a `VkExportMetalSharedEventInfoEXT` structure in the `pNext` chain of the `pMetalObjectsInfo` parameter of a vkExportMetalObjectsEXT call.

The `VkExportMetalSharedEventInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkExportMetalSharedEventInfoEXT {
        VkStructureType      sType;
        const void*          pNext;
        VkSemaphore          semaphore;
        VkEvent              event;
        MTLSharedEvent_id    mtlSharedEvent;
    } VkExportMetalSharedEventInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `semaphore` is `VK_NULL_HANDLE` or a VkSemaphore.

- `event` is `VK_NULL_HANDLE` or a VkEvent.

- `mtlSharedEvent` is the Metal `id<MTLSharedEvent>` object underlying the VkSemaphore or VkEvent object in `semaphore` or `event`, respectively. The implementation will return the `MTLSharedEvent` in this member, or it will return `NULL` if no `MTLSharedEvent` could be found underlying the VkSemaphore or VkEvent object.

Valid Usage (Implicit)

- VUID-VkExportMetalSharedEventInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_EXPORT_METAL_SHARED_EVENT_INFO_EXT`

- VUID-VkExportMetalSharedEventInfoEXT-semaphore-parameter
  If `semaphore` is not VK_NULL_HANDLE, `semaphore` must be a valid VkSemaphore handle

- VUID-VkExportMetalSharedEventInfoEXT-event-parameter
  If `event` is not VK_NULL_HANDLE, `event` must be a valid VkEvent handle

- VUID-VkExportMetalSharedEventInfoEXT-commonparent
  Both of `event`, and `semaphore` that are valid handles of non-ignored parameters must have been created, allocated, or retrieved from the same VkDevice

To import a Metal `MTLSharedEvent` object to underlie a VkSemaphore or VkEvent object, include a `VkImportMetalSharedEventInfoEXT` structure in the `pNext` chain of the VkSemaphoreCreateInfo or VkEventCreateInfo structure in a vkCreateSemaphore or vkCreateEvent command, respectively.

The `VkImportMetalSharedEventInfoEXT` structure is defined as:

    // Provided by VK_EXT_metal_objects
    typedef struct VkImportMetalSharedEventInfoEXT {
        VkStructureType      sType;
        const void*          pNext;
        MTLSharedEvent_id    mtlSharedEvent;
    } VkImportMetalSharedEventInfoEXT;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `mtlSharedEvent` is the Metal `id<MTLSharedEvent>` object that is to underlie the VkSemaphore or VkEvent.

If the `pNext` chain of the VkSemaphoreCreateInfo structure includes both `VkImportMetalSharedEventInfoEXT` and VkSemaphoreTypeCreateInfo, the `signaledValue` property of the imported `MTLSharedEvent` object will be set to `initialValue` of VkSemaphoreTypeCreateInfo.

Valid Usage (Implicit)

- VUID-VkImportMetalSharedEventInfoEXT-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_IMPORT_METAL_SHARED_EVENT_INFO_EXT`

The type `id<MTLSharedEvent>` is defined in Apple’s Metal framework, but to remove an unnecessary compile-time dependency, an incomplete type definition of `MTLSharedEvent_id` is provided in the Vulkan headers:

    // Provided by VK_EXT_metal_objects
    #ifdef __OBJC__
    @protocol MTLSharedEvent;
    typedef id<MTLSharedEvent> MTLSharedEvent_id;
    #else
    typedef void* MTLSharedEvent_id;
    #endif

#### 11.2.11. Device Group Memory Allocations

If the `pNext` chain of VkMemoryAllocateInfo includes a `VkMemoryAllocateFlagsInfo` structure, then that structure includes flags and a device mask controlling how many instances of the memory will be allocated.

The `VkMemoryAllocateFlagsInfo` structure is defined as:

    // Provided by VK_VERSION_1_1
    typedef struct VkMemoryAllocateFlagsInfo {
        VkStructureType          sType;
        const void*              pNext;
        VkMemoryAllocateFlags    flags;
        uint32_t                 deviceMask;
    } VkMemoryAllocateFlagsInfo;

or the equivalent

    // Provided by VK_KHR_device_group
    typedef VkMemoryAllocateFlagsInfo VkMemoryAllocateFlagsInfoKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `flags` is a bitmask of VkMemoryAllocateFlagBits controlling the allocation.

- `deviceMask` is a mask of physical devices in the logical device, indicating that memory must be allocated on each device in the mask, if `VK_MEMORY_ALLOCATE_DEVICE_MASK_BIT` is set in `flags`.

If `VK_MEMORY_ALLOCATE_DEVICE_MASK_BIT` is not set, the number of instances allocated depends on whether `VK_MEMORY_HEAP_MULTI_INSTANCE_BIT` is set in the memory heap. If `VK_MEMORY_HEAP_MULTI_INSTANCE_BIT` is set, then memory is allocated for every physical device in the logical device (as if `deviceMask` has bits set for all device indices). If `VK_MEMORY_HEAP_MULTI_INSTANCE_BIT` is not set, then a single instance of memory is allocated (as if `deviceMask` is set to one).

On some implementations, allocations from a multi-instance heap may consume memory on all physical devices even if the `deviceMask` excludes some devices. If VkPhysicalDeviceGroupProperties::`subsetAllocation` is `VK_TRUE`, then memory is only consumed for the devices in the device mask.

| Note In practice, most allocations on a multi-instance heap will be allocated across all physical devices. Unicast allocation support is an optional optimization for a minority of allocations.

Valid Usage

- VUID-VkMemoryAllocateFlagsInfo-deviceMask-00675
  If `VK_MEMORY_ALLOCATE_DEVICE_MASK_BIT` is set, `deviceMask` must be a valid device mask

- VUID-VkMemoryAllocateFlagsInfo-deviceMask-00676
  If `VK_MEMORY_ALLOCATE_DEVICE_MASK_BIT` is set, `deviceMask` must not be zero

Valid Usage (Implicit)

- VUID-VkMemoryAllocateFlagsInfo-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_FLAGS_INFO`

- VUID-VkMemoryAllocateFlagsInfo-flags-parameter
  `flags` must be a valid combination of VkMemoryAllocateFlagBits values

Bits which can be set in VkMemoryAllocateFlagsInfo::`flags`, controlling device memory allocation, are:

    // Provided by VK_VERSION_1_1
    typedef enum VkMemoryAllocateFlagBits {
        VK_MEMORY_ALLOCATE_DEVICE_MASK_BIT = 0x00000001,
      // Provided by VK_VERSION_1_2
        VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT = 0x00000002,
      // Provided by VK_VERSION_1_2
        VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_CAPTURE_REPLAY_BIT = 0x00000004,
      // Provided by VK_KHR_device_group
        VK_MEMORY_ALLOCATE_DEVICE_MASK_BIT_KHR = VK_MEMORY_ALLOCATE_DEVICE_MASK_BIT,
      // Provided by VK_KHR_buffer_device_address
        VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT_KHR = VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT,
      // Provided by VK_KHR_buffer_device_address
        VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_CAPTURE_REPLAY_BIT_KHR = VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_CAPTURE_REPLAY_BIT,
    } VkMemoryAllocateFlagBits;

or the equivalent

    // Provided by VK_KHR_device_group
    typedef VkMemoryAllocateFlagBits VkMemoryAllocateFlagBitsKHR;

- `VK_MEMORY_ALLOCATE_DEVICE_MASK_BIT` specifies that memory will be allocated for the devices in VkMemoryAllocateFlagsInfo::`deviceMask`.

- `VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT` specifies that the memory can be attached to a buffer object created with the `VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT` bit set in `usage`, and that the memory handle can be used to retrieve an opaque address via vkGetDeviceMemoryOpaqueCaptureAddress.

- `VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_CAPTURE_REPLAY_BIT` specifies that the memory’s address can be saved and reused on a subsequent run (e.g. for trace capture and replay), see VkBufferOpaqueCaptureAddressCreateInfo for more detail.

    // Provided by VK_VERSION_1_1
    typedef VkFlags VkMemoryAllocateFlags;

or the equivalent

    // Provided by VK_KHR_device_group
    typedef VkMemoryAllocateFlags VkMemoryAllocateFlagsKHR;

`VkMemoryAllocateFlags` is a bitmask type for setting a mask of zero or more VkMemoryAllocateFlagBits.

#### 11.2.12. Opaque Capture Address Allocation

To request a specific device address for a memory allocation, add a VkMemoryOpaqueCaptureAddressAllocateInfo structure to the `pNext` chain of the VkMemoryAllocateInfo structure. The `VkMemoryOpaqueCaptureAddressAllocateInfo` structure is defined as:

    // Provided by VK_VERSION_1_2
    typedef struct VkMemoryOpaqueCaptureAddressAllocateInfo {
        VkStructureType    sType;
        const void*        pNext;
        uint64_t           opaqueCaptureAddress;
    } VkMemoryOpaqueCaptureAddressAllocateInfo;

or the equivalent

    // Provided by VK_KHR_buffer_device_address
    typedef VkMemoryOpaqueCaptureAddressAllocateInfo VkMemoryOpaqueCaptureAddressAllocateInfoKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `opaqueCaptureAddress` is the opaque capture address requested for the memory allocation.

If `opaqueCaptureAddress` is zero, no specific address is requested.

If `opaqueCaptureAddress` is not zero, it should be an address retrieved from vkGetDeviceMemoryOpaqueCaptureAddress on an identically created memory allocation on the same implementation.

| Note In most cases, it is expected that a non-zero `opaqueAddress` is an address retrieved from vkGetDeviceMemoryOpaqueCaptureAddress on an identically created memory allocation. If this is not the case, it is likely that `VK_ERROR_INVALID_OPAQUE_CAPTURE_ADDRESS` errors will occur. This is, however, not a strict requirement because trace capture/replay tools may need to adjust memory allocation parameters for imported memory.

If this structure is not present, it is as if `opaqueCaptureAddress` is zero.

Valid Usage (Implicit)

- VUID-VkMemoryOpaqueCaptureAddressAllocateInfo-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MEMORY_OPAQUE_CAPTURE_ADDRESS_ALLOCATE_INFO`

#### 11.2.13. Freeing Device Memory

To free a memory object, call:

    // Provided by VK_VERSION_1_0
    void vkFreeMemory(
        VkDevice                                    device,
        VkDeviceMemory                              memory,
        const VkAllocationCallbacks*                pAllocator);

- `device` is the logical device that owns the memory.

- `memory` is the VkDeviceMemory object to be freed.

- `pAllocator` controls host memory allocation as described in the Memory Allocation chapter.

Before freeing a memory object, an application must ensure the memory object is no longer in use by the device — for example by command buffers in the pending state. Memory can be freed whilst still bound to resources, but those resources must not be used afterwards. Freeing a memory object releases the reference it held, if any, to its payload. If there are still any bound images or buffers, the memory object’s payload may not be immediately released by the implementation, but must be released by the time all bound images and buffers have been destroyed. Once all references to a payload are released, it is returned to the heap from which it was allocated.

How memory objects are bound to Images and Buffers is described in detail in the Resource Memory Association section.

If a memory object is mapped at the time it is freed, it is implicitly unmapped.

| Note As described below, host writes are not implicitly flushed when the memory object is unmapped, but the implementation must guarantee that writes that have not been flushed do not affect any other memory.

Valid Usage

- VUID-vkFreeMemory-memory-00677
  All submitted commands that refer to `memory` (via images or buffers) must have completed execution

Valid Usage (Implicit)

- VUID-vkFreeMemory-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkFreeMemory-memory-parameter
  If `memory` is not VK_NULL_HANDLE, `memory` must be a valid VkDeviceMemory handle

- VUID-vkFreeMemory-pAllocator-parameter
  If `pAllocator` is not `NULL`, `pAllocator` must be a valid pointer to a valid VkAllocationCallbacks structure

- VUID-vkFreeMemory-memory-parent
  If `memory` is a valid handle, it must have been created, allocated, or retrieved from `device`

Host Synchronization

- Host access to `memory` must be externally synchronized

#### 11.2.14. Host Access to Device Memory Objects

Memory objects created with vkAllocateMemory are not directly host accessible.

Memory objects created with the memory property `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT` are considered mappable. Memory objects must be mappable in order to be successfully mapped on the host.

To retrieve a host virtual address pointer to a region of a mappable memory object, call:

    // Provided by VK_VERSION_1_0
    VkResult vkMapMemory(
        VkDevice                                    device,
        VkDeviceMemory                              memory,
        VkDeviceSize                                offset,
        VkDeviceSize                                size,
        VkMemoryMapFlags                            flags,
        void**                                      ppData);

- `device` is the logical device that owns the memory.

- `memory` is the VkDeviceMemory object to be mapped.

- `offset` is a zero-based byte offset from the beginning of the memory object.

- `size` is the size of the memory range to map, or `VK_WHOLE_SIZE` to map from `offset` to the end of the allocation.

- `flags` is reserved for future use.

- `ppData` is a pointer to a `void *` variable in which is returned a host-accessible pointer to the beginning of the mapped range. This pointer minus `offset` must be aligned to at least VkPhysicalDeviceLimits::`minMemoryMapAlignment`.

After a successful call to `vkMapMemory` the memory object `memory` is considered to be currently host mapped.

| Note It is an application error to call `vkMapMemory` on a memory object that is already host mapped.

| Note `vkMapMemory` will fail if the implementation is unable to allocate an appropriately sized contiguous virtual address range, e.g. due to virtual address space fragmentation or platform limits. In such cases, `vkMapMemory` must return `VK_ERROR_MEMORY_MAP_FAILED`. The application can improve the likelihood of success by reducing the size of the mapped range and/or removing unneeded mappings using vkUnmapMemory.

`vkMapMemory` does not check whether the device memory is currently in use before returning the host-accessible pointer. The application must guarantee that any previously submitted command that writes to this range has completed before the host reads from or writes to that range, and that any previously submitted command that reads from that range has completed before the host writes to that region (see here for details on fulfilling such a guarantee). If the device memory was allocated without the `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` set, these guarantees must be made for an extended range: the application must round down the start of the range to the nearest multiple of VkPhysicalDeviceLimits::`nonCoherentAtomSize`, and round the end of the range up to the nearest multiple of VkPhysicalDeviceLimits::`nonCoherentAtomSize`.

While a range of device memory is host mapped, the application is responsible for synchronizing both device and host access to that memory range.

| Note It is important for the application developer to become meticulously familiar with all of the mechanisms described in the chapter on Synchronization and Cache Control as they are crucial to maintaining memory access ordering.

Valid Usage

- VUID-vkMapMemory-memory-00678
  `memory` must not be currently host mapped

- VUID-vkMapMemory-offset-00679
  `offset` must be less than the size of `memory`

- VUID-vkMapMemory-size-00680
  If `size` is not equal to `VK_WHOLE_SIZE`, `size` must be greater than `0`

- VUID-vkMapMemory-size-00681
  If `size` is not equal to `VK_WHOLE_SIZE`, `size` must be less than or equal to the size of the `memory` minus `offset`

- VUID-vkMapMemory-memory-00682
  `memory` must have been created with a memory type that reports `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT`

- VUID-vkMapMemory-memory-00683
  `memory` must not have been allocated with multiple instances

Valid Usage (Implicit)

- VUID-vkMapMemory-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkMapMemory-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

- VUID-vkMapMemory-flags-zerobitmask
  `flags` must be `0`

- VUID-vkMapMemory-ppData-parameter
  `ppData` must be a valid pointer to a pointer value

- VUID-vkMapMemory-memory-parent
  `memory` must have been created, allocated, or retrieved from `device`

Host Synchronization

- Host access to `memory` must be externally synchronized

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_OUT_OF_DEVICE_MEMORY`

  - `VK_ERROR_MEMORY_MAP_FAILED`

    // Provided by VK_VERSION_1_0
    typedef VkFlags VkMemoryMapFlags;

`VkMemoryMapFlags` is a bitmask type for setting a mask, but is currently reserved for future use.

Two commands are provided to enable applications to work with non-coherent memory allocations: `vkFlushMappedMemoryRanges` and `vkInvalidateMappedMemoryRanges`.

| Note If the memory object was created with the `VK_MEMORY_PROPERTY_HOST_COHERENT_BIT` set, `vkFlushMappedMemoryRanges` and `vkInvalidateMappedMemoryRanges` are unnecessary and may have a performance cost. However, availability and visibility operations still need to be managed on the device. See the description of host access types for more information.

| Note While memory objects imported from a handle type of `VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_ALLOCATION_BIT_EXT` or `VK_EXTERNAL_MEMORY_HANDLE_TYPE_HOST_MAPPED_FOREIGN_MEMORY_BIT_EXT` are inherently mapped to host address space, they are not considered to be host mapped device memory unless they are explicitly host mapped using vkMapMemory. That means flushing or invalidating host caches with respect to host accesses performed on such memory through the original host pointer specified at import time is the responsibility of the application and must be performed with appropriate synchronization primitives provided by the platform which are outside the scope of Vulkan. `vkFlushMappedMemoryRanges` and `vkInvalidateMappedMemoryRanges`, however, can still be used on such memory objects to synchronize host accesses performed through the host pointer of the host mapped device memory range returned by vkMapMemory.

To flush ranges of non-coherent memory from the host caches, call:

    // Provided by VK_VERSION_1_0
    VkResult vkFlushMappedMemoryRanges(
        VkDevice                                    device,
        uint32_t                                    memoryRangeCount,
        const VkMappedMemoryRange*                  pMemoryRanges);

- `device` is the logical device that owns the memory ranges.

- `memoryRangeCount` is the length of the `pMemoryRanges` array.

- `pMemoryRanges` is a pointer to an array of VkMappedMemoryRange structures describing the memory ranges to flush.

`vkFlushMappedMemoryRanges` guarantees that host writes to the memory ranges described by `pMemoryRanges` are made available to the host memory domain, such that they can be made available to the device memory domain via memory domain operations using the `VK_ACCESS_HOST_WRITE_BIT` access type.

Within each range described by `pMemoryRanges`, each set of `nonCoherentAtomSize` bytes in that range is flushed if any byte in that set has been written by the host since it was first host mapped, or the last time it was flushed. If `pMemoryRanges` includes sets of `nonCoherentAtomSize` bytes where no bytes have been written by the host, those bytes must not be flushed.

Unmapping non-coherent memory does not implicitly flush the host mapped memory, and host writes that have not been flushed may not ever be visible to the device. However, implementations must ensure that writes that have not been flushed do not become visible to any other memory.

| Note The above guarantee avoids a potential memory corruption in scenarios where host writes to a mapped memory object have not been flushed before the memory is unmapped (or freed), and the virtual address range is subsequently reused for a different mapping (or memory allocation).

Valid Usage (Implicit)

- VUID-vkFlushMappedMemoryRanges-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkFlushMappedMemoryRanges-pMemoryRanges-parameter
  `pMemoryRanges` must be a valid pointer to an array of `memoryRangeCount` valid VkMappedMemoryRange structures

- VUID-vkFlushMappedMemoryRanges-memoryRangeCount-arraylength
  `memoryRangeCount` must be greater than `0`

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_OUT_OF_DEVICE_MEMORY`

To invalidate ranges of non-coherent memory from the host caches, call:

    // Provided by VK_VERSION_1_0
    VkResult vkInvalidateMappedMemoryRanges(
        VkDevice                                    device,
        uint32_t                                    memoryRangeCount,
        const VkMappedMemoryRange*                  pMemoryRanges);

- `device` is the logical device that owns the memory ranges.

- `memoryRangeCount` is the length of the `pMemoryRanges` array.

- `pMemoryRanges` is a pointer to an array of VkMappedMemoryRange structures describing the memory ranges to invalidate.

`vkInvalidateMappedMemoryRanges` guarantees that device writes to the memory ranges described by `pMemoryRanges`, which have been made available to the host memory domain using the `VK_ACCESS_HOST_WRITE_BIT` and `VK_ACCESS_HOST_READ_BIT` access types, are made visible to the host. If a range of non-coherent memory is written by the host and then invalidated without first being flushed, its contents are undefined.

Within each range described by `pMemoryRanges`, each set of `nonCoherentAtomSize` bytes in that range is invalidated if any byte in that set has been written by the device since it was first host mapped, or the last time it was invalidated.

| Note Mapping non-coherent memory does not implicitly invalidate that memory.

Valid Usage (Implicit)

- VUID-vkInvalidateMappedMemoryRanges-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkInvalidateMappedMemoryRanges-pMemoryRanges-parameter
  `pMemoryRanges` must be a valid pointer to an array of `memoryRangeCount` valid VkMappedMemoryRange structures

- VUID-vkInvalidateMappedMemoryRanges-memoryRangeCount-arraylength
  `memoryRangeCount` must be greater than `0`

Return Codes

Success

  - `VK_SUCCESS`

Failure

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_OUT_OF_DEVICE_MEMORY`

The `VkMappedMemoryRange` structure is defined as:

    // Provided by VK_VERSION_1_0
    typedef struct VkMappedMemoryRange {
        VkStructureType    sType;
        const void*        pNext;
        VkDeviceMemory     memory;
        VkDeviceSize       offset;
        VkDeviceSize       size;
    } VkMappedMemoryRange;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memory` is the memory object to which this range belongs.

- `offset` is the zero-based byte offset from the beginning of the memory object.

- `size` is either the size of range, or `VK_WHOLE_SIZE` to affect the range from `offset` to the end of the current mapping of the allocation.

Valid Usage

- VUID-VkMappedMemoryRange-memory-00684
  `memory` must be currently host mapped

- VUID-VkMappedMemoryRange-size-00685
  If `size` is not equal to `VK_WHOLE_SIZE`, `offset` and `size` must specify a range contained within the currently mapped range of `memory`

- VUID-VkMappedMemoryRange-size-00686
  If `size` is equal to `VK_WHOLE_SIZE`, `offset` must be within the currently mapped range of `memory`

- VUID-VkMappedMemoryRange-offset-00687
  `offset` must be a multiple of VkPhysicalDeviceLimits::`nonCoherentAtomSize`

- VUID-VkMappedMemoryRange-size-01389
  If `size` is equal to `VK_WHOLE_SIZE`, the end of the current mapping of `memory` must either be a multiple of VkPhysicalDeviceLimits::`nonCoherentAtomSize` bytes from the beginning of the memory object, or be equal to the end of the memory object

- VUID-VkMappedMemoryRange-size-01390
  If `size` is not equal to `VK_WHOLE_SIZE`, `size` must either be a multiple of VkPhysicalDeviceLimits::`nonCoherentAtomSize`, or `offset` plus `size` must equal the size of `memory`

Valid Usage (Implicit)

- VUID-VkMappedMemoryRange-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE`

- VUID-VkMappedMemoryRange-pNext-pNext
  `pNext` must be `NULL`

- VUID-VkMappedMemoryRange-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

To unmap a memory object once host access to it is no longer needed by the application, call:

    // Provided by VK_VERSION_1_0
    void vkUnmapMemory(
        VkDevice                                    device,
        VkDeviceMemory                              memory);

- `device` is the logical device that owns the memory.

- `memory` is the memory object to be unmapped.

Valid Usage

- VUID-vkUnmapMemory-memory-00689
  `memory` must be currently host mapped

Valid Usage (Implicit)

- VUID-vkUnmapMemory-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkUnmapMemory-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

- VUID-vkUnmapMemory-memory-parent
  `memory` must have been created, allocated, or retrieved from `device`

Host Synchronization

- Host access to `memory` must be externally synchronized

#### 11.2.15. Lazily Allocated Memory

If the memory object is allocated from a heap with the `VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT` bit set, that object’s backing memory may be provided by the implementation lazily. The actual committed size of the memory may initially be as small as zero (or as large as the requested size), and monotonically increases as additional memory is needed.

A memory type with this flag set is only allowed to be bound to a `VkImage` whose usage flags include `VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BIT`.

| Note Using lazily allocated memory objects for framebuffer attachments that are not needed once a render pass instance has completed may allow some implementations to never allocate memory for such attachments.

To determine the amount of lazily-allocated memory that is currently committed for a memory object, call:

    // Provided by VK_VERSION_1_0
    void vkGetDeviceMemoryCommitment(
        VkDevice                                    device,
        VkDeviceMemory                              memory,
        VkDeviceSize*                               pCommittedMemoryInBytes);

- `device` is the logical device that owns the memory.

- `memory` is the memory object being queried.

- `pCommittedMemoryInBytes` is a pointer to a `VkDeviceSize` value in which the number of bytes currently committed is returned, on success.

The implementation may update the commitment at any time, and the value returned by this query may be out of date.

The implementation guarantees to allocate any committed memory from the `heapIndex` indicated by the memory type that the memory object was created with.

Valid Usage

- VUID-vkGetDeviceMemoryCommitment-memory-00690
  `memory` must have been created with a memory type that reports `VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT`

Valid Usage (Implicit)

- VUID-vkGetDeviceMemoryCommitment-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetDeviceMemoryCommitment-memory-parameter
  `memory` must be a valid VkDeviceMemory handle

- VUID-vkGetDeviceMemoryCommitment-pCommittedMemoryInBytes-parameter
  `pCommittedMemoryInBytes` must be a valid pointer to a `VkDeviceSize` value

- VUID-vkGetDeviceMemoryCommitment-memory-parent
  `memory` must have been created, allocated, or retrieved from `device`

#### 11.2.16. Protected Memory

Protected memory divides device memory into protected device memory and unprotected device memory.

Protected memory adds the following concepts:

- Memory:

  - Unprotected device memory, which can be visible to the device and can be visible to the host

  - Protected device memory, which can be visible to the device but must not be visible to the host

- Resources:

  - Unprotected images and unprotected buffers, to which unprotected memory can be bound

  - Protected images and protected buffers, to which protected memory can be bound

- Command buffers:

  - Unprotected command buffers, which can be submitted to a device queue to execute unprotected queue operations

  - Protected command buffers, which can be submitted to a protected-capable device queue to execute protected queue operations

- Device queues:

  - Unprotected device queues, to which unprotected command buffers can be submitted

  - Protected-capable device queues, to which unprotected command buffers or protected command buffers can be submitted

- Queue submissions

  - Unprotected queue submissions, through which unprotected command buffers can be submitted

  - Protected queue submissions, through which protected command buffers can be submitted

- Queue operations

  - Unprotected queue operations

  - Protected queue operations

##### Protected Memory Access Rules

If VkPhysicalDeviceProtectedMemoryProperties::`protectedNoFault` is `VK_FALSE`, applications must not perform any of the following operations:

- Write to unprotected memory within protected queue operations.

- Access protected memory within protected queue operations other than in framebuffer-space pipeline stages, the compute shader stage, or the transfer stage.

- Perform a query within protected queue operations.

If VkPhysicalDeviceProtectedMemoryProperties::`protectedNoFault` is `VK_TRUE`, these operations are valid, but reads will return undefined values, and writes will either be dropped or store undefined values.

Additionally, indirect operations must not be performed within protected queue operations.

Whether these operations are valid or not, or if any other invalid usage is performed, the implementation must guarantee that:

- Protected device memory must never be visible to the host.

- Values written to unprotected device memory must not be a function of values from protected memory.

#### 11.2.17. External Memory Handle Types

##### Android Hardware Buffer

Android’s NDK defines `AHardwareBuffer` objects, which represent device memory that is shareable across processes and that can be accessed by a variety of media APIs and the hardware used to implement them. These Android hardware buffer objects may be imported into VkDeviceMemory objects for access via Vulkan, or exported from Vulkan. An VkImage or VkBuffer can be bound to the imported or exported VkDeviceMemory object if it is created with `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID`.

To remove an unnecessary compile-time dependency, an incomplete type definition of `AHardwareBuffer` is provided in the Vulkan headers:

    // Provided by VK_ANDROID_external_memory_android_hardware_buffer
    struct AHardwareBuffer;

The actual `AHardwareBuffer` type is defined in Android NDK headers.

| Note The NDK format, usage, and size/dimensions of an `AHardwareBuffer` object can be obtained with the `AHardwareBuffer_describe` function. While Android hardware buffers can be imported to or exported from Vulkan without using that function, valid usage and implementation behavior is defined in terms of the `AHardwareBuffer_Desc` properties it returns.

Android hardware buffer objects are reference-counted using Android NDK functions outside of the scope of this specification. A VkDeviceMemory imported from an Android hardware buffer or that can be exported to an Android hardware buffer must acquire a reference to its `AHardwareBuffer` object, and must release this reference when the device memory is freed. During the host execution of a Vulkan command that has an Android hardware buffer as a parameter (including indirect parameters via `pNext` chains), the application must not decrement the Android hardware buffer’s reference count to zero.

Android hardware buffers can be mapped and unmapped for CPU access using the NDK functions. These lock and unlock APIs are considered to acquire and release ownership of the Android hardware buffer, and applications must follow the rules described in External Resource Sharing to transfer ownership between the Vulkan instance and these native APIs.

Android hardware buffers can be shared with external APIs and Vulkan instances on the same device, and also with foreign devices. When transferring ownership of the Android hardware buffer, the external and foreign special queue families described in Queue Family Ownership Transfer are not identical. All APIs which produce or consume Android hardware buffers are considered to use foreign devices, except OpenGL ES contexts and Vulkan logical devices that have matching device and driver UUIDs. Implementations may treat a transfer to or from the foreign queue family as if it were a transfer to or from the external queue family when the Android hardware buffer’s usage only permits it to be used on the same physical device.

###### Android Hardware Buffer Optimal Usages

Vulkan buffer and image usage flags do not correspond exactly to Android hardware buffer usage flags. When allocating Android hardware buffers with non-Vulkan APIs, if any `AHARDWAREBUFFER_USAGE_GPU_*` usage bits are included, by default the allocator must allocate the memory in such a way that it supports Vulkan usages and creation flags in the usage equivalence table which do not have Android hardware buffer equivalents.

An VkAndroidHardwareBufferUsageANDROID structure can be included in the `pNext` chain of a VkImageFormatProperties2 structure passed to vkGetPhysicalDeviceImageFormatProperties2 to obtain optimal Android hardware buffer usage flags for specific Vulkan resource creation parameters. Some usage flags returned by these commands are required based on the input parameters, but additional vendor-specific usage flags (`AHARDWAREBUFFER_USAGE_VENDOR_*`) may also be returned. Any Android hardware buffer allocated with these vendor-specific usage flags and imported to Vulkan must only be bound to resources created with parameters that are a subset of the parameters used to obtain the Android hardware buffer usage, since the memory may have been allocated in a way incompatible with other parameters. If an Android hardware buffer is successfully allocated with additional non-vendor-specific usage flags in addition to the recommended usage, it must support being used in the same ways as an Android hardware buffer allocated with only the recommended usage, and also in ways indicated by the additional usage.

###### Android Hardware Buffer External Formats

Android hardware buffers may represent images using implementation-specific formats, layouts, color models, etc., which do not have Vulkan equivalents. Such external formats are commonly used by external image sources such as video decoders or cameras. Vulkan can import Android hardware buffers that have external formats, but since the image contents are in an undiscoverable and possibly proprietary representation, images with external formats must only be used as sampled images, must only be sampled with a sampler that has Y′CBCR conversion enabled, and must have optimal tiling.

Images that will be backed by an Android hardware buffer can use an external format by setting VkImageCreateInfo::`format` to `VK_FORMAT_UNDEFINED` and including a VkExternalFormatANDROID structure in the `pNext` chain. Images can be created with an external format even if the Android hardware buffer has a format which has an equivalent Vulkan format to enable consistent handling of images from sources that might use either category of format. However, all images created with an external format are subject to the valid usage requirements associated with external formats, even if the Android hardware buffer’s format has a Vulkan equivalent. The external format of an Android hardware buffer can be obtained by passing a VkAndroidHardwareBufferFormatPropertiesANDROID structure to vkGetAndroidHardwareBufferPropertiesANDROID.

###### Android Hardware Buffer Image Resources

Android hardware buffers have intrinsic width, height, format, and usage properties, so Vulkan images bound to memory imported from an Android hardware buffer must use dedicated allocations: `VkMemoryDedicatedRequirements`::`requiresDedicatedAllocation` must be `VK_TRUE` for images created with VkExternalMemoryImageCreateInfo::`handleTypes` that includes `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID`. When creating an image that will be bound to an imported Android hardware buffer, the image creation parameters must be equivalent to the `AHardwareBuffer` properties as described by the valid usage of VkMemoryAllocateInfo. Similarly, device memory allocated for a dedicated image must not be exported to an Android hardware buffer until it has been bound to that image, and the implementation must return an Android hardware buffer with properties derived from the image:

- The `width` and `height` members of `AHardwareBuffer_Desc` must be the same as the `width` and `height` members of VkImageCreateInfo::`extent`, respectively.

- The `layers` member of `AHardwareBuffer_Desc` must be the same as the `arrayLayers` member of VkImageCreateInfo.

- The `format` member of `AHardwareBuffer_Desc` must be equivalent to VkImageCreateInfo::`format` as defined by AHardwareBuffer Format Equivalence.

- The `usage` member of `AHardwareBuffer_Desc` must include bits corresponding to bits included in VkImageCreateInfo::`usage` and VkImageCreateInfo::`flags` where such a correspondence exists according to AHardwareBuffer Usage Equivalence. It may also include additional usage bits, including vendor-specific usages. Presence of vendor usage bits may make the Android hardware buffer only usable in ways indicated by the image creation parameters, even when used outside Vulkan, in a similar way that allocating the Android hardware buffer with usage returned in VkAndroidHardwareBufferUsageANDROID does.

Implementations may support fewer combinations of image creation parameters for images with Android hardware buffer external handle type than for non-external images. Support for a given set of parameters can be determined by passing VkExternalImageFormatProperties to vkGetPhysicalDeviceImageFormatProperties2 with `handleType` set to `VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID`. Any Android hardware buffer successfully allocated outside Vulkan with usage that includes `AHARDWAREBUFFER_USAGE_GPU_*` must be supported when using equivalent Vulkan image parameters. If a given choice of image parameters are supported for import, they can also be used to create an image and memory that will be exported to an Android hardware buffer.

Table 13. AHardwareBuffer Format Equivalence
AHardwareBuffer Format | Vulkan Format
--- | ---
`AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM` | `VK_FORMAT_R8G8B8A8_UNORM`
`AHARDWAREBUFFER_FORMAT_R8G8B8X8_UNORM` 1 | `VK_FORMAT_R8G8B8A8_UNORM`
`AHARDWAREBUFFER_FORMAT_R8G8B8_UNORM` | `VK_FORMAT_R8G8B8_UNORM`
`AHARDWAREBUFFER_FORMAT_R5G6B5_UNORM` | `VK_FORMAT_R5G6B5_UNORM_PACK16`
`AHARDWAREBUFFER_FORMAT_R16G16B16A16_FLOAT` | `VK_FORMAT_R16G16B16A16_SFLOAT`
`AHARDWAREBUFFER_FORMAT_R10G10B10A2_UNORM` | `VK_FORMAT_A2B10G10R10_UNORM_PACK32`
`AHARDWAREBUFFER_FORMAT_D16_UNORM` | `VK_FORMAT_D16_UNORM`
`AHARDWAREBUFFER_FORMAT_D24_UNORM` | `VK_FORMAT_X8_D24_UNORM_PACK32`
`AHARDWAREBUFFER_FORMAT_D24_UNORM_S8_UINT` | `VK_FORMAT_D24_UNORM_S8_UINT`
`AHARDWAREBUFFER_FORMAT_D32_FLOAT` | `VK_FORMAT_D32_SFLOAT`
`AHARDWAREBUFFER_FORMAT_D32_FLOAT_S8_UINT` | `VK_FORMAT_D32_SFLOAT_S8_UINT`
`AHARDWAREBUFFER_FORMAT_S8_UINT` | `VK_FORMAT_S8_UINT`

Table 14. AHardwareBuffer Usage Equivalence
AHardwareBuffer Usage | Vulkan Usage or Creation Flag
--- | ---
None | `VK_IMAGE_USAGE_TRANSFER_SRC_BIT`
None | `VK_IMAGE_USAGE_TRANSFER_DST_BIT`
`AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE` | `VK_IMAGE_USAGE_SAMPLED_BIT`
`AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE` | `VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT`
`AHARDWAREBUFFER_USAGE_GPU_FRAMEBUFFER` 3 | `VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT`
`AHARDWAREBUFFER_USAGE_GPU_FRAMEBUFFER` 3 | `VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT`
`AHARDWAREBUFFER_USAGE_GPU_CUBE_MAP` | `VK_IMAGE_CREATE_CUBE_COMPATIBLE_BIT`
`AHARDWAREBUFFER_USAGE_GPU_MIPMAP_COMPLETE` | None 2
`AHARDWAREBUFFER_USAGE_PROTECTED_CONTENT` | `VK_IMAGE_CREATE_PROTECTED_BIT`
None | `VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT`
None | `VK_IMAGE_CREATE_EXTENDED_USAGE_BIT`
`AHARDWAREBUFFER_USAGE_GPU_DATA_BUFFER` 4 | `VK_IMAGE_USAGE_STORAGE_BIT`

1

  Vulkan does not differentiate between `AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM` and `AHARDWAREBUFFER_FORMAT_R8G8B8X8_UNORM`: they both behave as `VK_FORMAT_R8G8B8A8_UNORM`. After an external entity writes to a `AHARDWAREBUFFER_FORMAT_R8G8B8X8_UNORM` Android hardware buffer, the values read by Vulkan from the X/A component are undefined. To emulate the traditional behavior of the X component during sampling or blending, applications should use `VK_COMPONENT_SWIZZLE_ONE` in image view component mappings and `VK_BLEND_FACTOR_ONE` in color blend factors. There is no way to avoid copying these undefined values when copying from such an image to another image or buffer.

2

  The `AHARDWAREBUFFER_USAGE_GPU_MIPMAP_COMPLETE` flag does not correspond to a Vulkan image usage or creation flag. Instead, its presence indicates that the Android hardware buffer contains a complete mipmap chain, and its absence indicates that the Android hardware buffer contains only a single mip level.

3

  Only image usages valid for the format are valid. It would be invalid to take a Android Hardware Buffer with a format of `AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM` that has a `AHARDWAREBUFFER_USAGE_GPU_FRAMEBUFFER` usage and try to create an image with `VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT`.

4

  In combination with a hardware buffer format other than `BLOB`.

| Note When using `VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT` with Android hardware buffer images, applications should use VkImageFormatListCreateInfo to inform the implementation which view formats will be used with the image. For some common sets of format, this allows some implementations to provide significantly better performance when accessing the image via Vulkan.

###### Android Hardware Buffer Buffer Resources

Android hardware buffers with a format of `AHARDWAREBUFFER_FORMAT_BLOB` and usage that includes `AHARDWAREBUFFER_USAGE_GPU_DATA_BUFFER` can be used as the backing store for VkBuffer objects. Such Android hardware buffers have a size in bytes specified by their `width`; `height` and `layers` are both `1`.

Unlike images, buffer resources backed by Android hardware buffers do not require dedicated allocations.

Exported `AHardwareBuffer` objects that do not have dedicated images must have a format of `AHARDWAREBUFFER_FORMAT_BLOB`, usage must include `AHARDWAREBUFFER_USAGE_GPU_DATA_BUFFER`, `width` must equal the device memory allocation size, and `height` and `layers` must be `1`.

#### 11.2.18. Peer Memory Features

Peer memory is memory that is allocated for a given physical device and then bound to a resource and accessed by a different physical device, in a logical device that represents multiple physical devices. Some ways of reading and writing peer memory may not be supported by a device.

To determine how peer memory can be accessed, call:

    // Provided by VK_VERSION_1_1
    void vkGetDeviceGroupPeerMemoryFeatures(
        VkDevice                                    device,
        uint32_t                                    heapIndex,
        uint32_t                                    localDeviceIndex,
        uint32_t                                    remoteDeviceIndex,
        VkPeerMemoryFeatureFlags*                   pPeerMemoryFeatures);

or the equivalent command

    // Provided by VK_KHR_device_group
    void vkGetDeviceGroupPeerMemoryFeaturesKHR(
        VkDevice                                    device,
        uint32_t                                    heapIndex,
        uint32_t                                    localDeviceIndex,
        uint32_t                                    remoteDeviceIndex,
        VkPeerMemoryFeatureFlags*                   pPeerMemoryFeatures);

- `device` is the logical device that owns the memory.

- `heapIndex` is the index of the memory heap from which the memory is allocated.

- `localDeviceIndex` is the device index of the physical device that performs the memory access.

- `remoteDeviceIndex` is the device index of the physical device that the memory is allocated for.

- `pPeerMemoryFeatures` is a pointer to a VkPeerMemoryFeatureFlags bitmask indicating which types of memory accesses are supported for the combination of heap, local, and remote devices.

Valid Usage

- VUID-vkGetDeviceGroupPeerMemoryFeatures-heapIndex-00691
  `heapIndex` must be less than `memoryHeapCount`

- VUID-vkGetDeviceGroupPeerMemoryFeatures-localDeviceIndex-00692
  `localDeviceIndex` must be a valid device index

- VUID-vkGetDeviceGroupPeerMemoryFeatures-remoteDeviceIndex-00693
  `remoteDeviceIndex` must be a valid device index

- VUID-vkGetDeviceGroupPeerMemoryFeatures-localDeviceIndex-00694
  `localDeviceIndex` must not equal `remoteDeviceIndex`

Valid Usage (Implicit)

- VUID-vkGetDeviceGroupPeerMemoryFeatures-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetDeviceGroupPeerMemoryFeatures-pPeerMemoryFeatures-parameter
  `pPeerMemoryFeatures` must be a valid pointer to a VkPeerMemoryFeatureFlags value

Bits which may be set in vkGetDeviceGroupPeerMemoryFeatures::`pPeerMemoryFeatures`, indicating supported peer memory features, are:

    // Provided by VK_VERSION_1_1
    typedef enum VkPeerMemoryFeatureFlagBits {
        VK_PEER_MEMORY_FEATURE_COPY_SRC_BIT = 0x00000001,
        VK_PEER_MEMORY_FEATURE_COPY_DST_BIT = 0x00000002,
        VK_PEER_MEMORY_FEATURE_GENERIC_SRC_BIT = 0x00000004,
        VK_PEER_MEMORY_FEATURE_GENERIC_DST_BIT = 0x00000008,
      // Provided by VK_KHR_device_group
        VK_PEER_MEMORY_FEATURE_COPY_SRC_BIT_KHR = VK_PEER_MEMORY_FEATURE_COPY_SRC_BIT,
      // Provided by VK_KHR_device_group
        VK_PEER_MEMORY_FEATURE_COPY_DST_BIT_KHR = VK_PEER_MEMORY_FEATURE_COPY_DST_BIT,
      // Provided by VK_KHR_device_group
        VK_PEER_MEMORY_FEATURE_GENERIC_SRC_BIT_KHR = VK_PEER_MEMORY_FEATURE_GENERIC_SRC_BIT,
      // Provided by VK_KHR_device_group
        VK_PEER_MEMORY_FEATURE_GENERIC_DST_BIT_KHR = VK_PEER_MEMORY_FEATURE_GENERIC_DST_BIT,
    } VkPeerMemoryFeatureFlagBits;

or the equivalent

    // Provided by VK_KHR_device_group
    typedef VkPeerMemoryFeatureFlagBits VkPeerMemoryFeatureFlagBitsKHR;

- `VK_PEER_MEMORY_FEATURE_COPY_SRC_BIT` specifies that the memory can be accessed as the source of any `vkCmdCopy*` command.

- `VK_PEER_MEMORY_FEATURE_COPY_DST_BIT` specifies that the memory can be accessed as the destination of any `vkCmdCopy*` command.

- `VK_PEER_MEMORY_FEATURE_GENERIC_SRC_BIT` specifies that the memory can be read as any memory access type.

- `VK_PEER_MEMORY_FEATURE_GENERIC_DST_BIT` specifies that the memory can be written as any memory access type. Shader atomics are considered to be writes.

| Note The peer memory features of a memory heap also apply to any accesses that may be performed during image layout transitions.

`VK_PEER_MEMORY_FEATURE_COPY_DST_BIT` must be supported for all host local heaps and for at least one device-local memory heap.

If a device does not support a peer memory feature, it is still valid to use a resource that includes both local and peer memory bindings with the corresponding access type as long as only the local bindings are actually accessed. For example, an application doing split-frame rendering would use framebuffer attachments that include both local and peer memory bindings, but would scissor the rendering to only update local memory.

    // Provided by VK_VERSION_1_1
    typedef VkFlags VkPeerMemoryFeatureFlags;

or the equivalent

    // Provided by VK_KHR_device_group
    typedef VkPeerMemoryFeatureFlags VkPeerMemoryFeatureFlagsKHR;

`VkPeerMemoryFeatureFlags` is a bitmask type for setting a mask of zero or more VkPeerMemoryFeatureFlagBits.

#### 11.2.19. Opaque Capture Address Query

To query a 64-bit opaque capture address value from a memory object, call:

    // Provided by VK_VERSION_1_2
    uint64_t vkGetDeviceMemoryOpaqueCaptureAddress(
        VkDevice                                    device,
        const VkDeviceMemoryOpaqueCaptureAddressInfo* pInfo);

or the equivalent command

    // Provided by VK_KHR_buffer_device_address
    uint64_t vkGetDeviceMemoryOpaqueCaptureAddressKHR(
        VkDevice                                    device,
        const VkDeviceMemoryOpaqueCaptureAddressInfo* pInfo);

- `device` is the logical device that the memory object was allocated on.

- `pInfo` is a pointer to a VkDeviceMemoryOpaqueCaptureAddressInfo structure specifying the memory object to retrieve an address for.

The 64-bit return value is an opaque address representing the start of `pInfo->memory`.

If the memory object was allocated with a non-zero value of VkMemoryOpaqueCaptureAddressAllocateInfo::`opaqueCaptureAddress`, the return value must be the same address.

| Note The expected usage for these opaque addresses is only for trace capture/replay tools to store these addresses in a trace and subsequently specify them during replay.

Valid Usage

- VUID-vkGetDeviceMemoryOpaqueCaptureAddress-None-03334
  The `bufferDeviceAddress` feature must be enabled

- VUID-vkGetDeviceMemoryOpaqueCaptureAddress-device-03335
  If `device` was created with multiple physical devices, then the `bufferDeviceAddressMultiDevice` feature must be enabled

Valid Usage (Implicit)

- VUID-vkGetDeviceMemoryOpaqueCaptureAddress-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetDeviceMemoryOpaqueCaptureAddress-pInfo-parameter
  `pInfo` must be a valid pointer to a valid VkDeviceMemoryOpaqueCaptureAddressInfo structure

The `VkDeviceMemoryOpaqueCaptureAddressInfo` structure is defined as:

    // Provided by VK_VERSION_1_2
    typedef struct VkDeviceMemoryOpaqueCaptureAddressInfo {
        VkStructureType    sType;
        const void*        pNext;
        VkDeviceMemory     memory;
    } VkDeviceMemoryOpaqueCaptureAddressInfo;

or the equivalent

    // Provided by VK_KHR_buffer_device_address
    typedef VkDeviceMemoryOpaqueCaptureAddressInfo VkDeviceMemoryOpaqueCaptureAddressInfoKHR;

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to a structure extending this structure.

- `memory` specifies the memory whose address is being queried.

Valid Usage

- VUID-VkDeviceMemoryOpaqueCaptureAddressInfo-memory-03336
  `memory` must have been allocated with `VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT`

Valid Usage (Implicit)

- VUID-VkDeviceMemoryOpaqueCaptureAddressInfo-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_DEVICE_MEMORY_OPAQUE_CAPTURE_ADDRESS_INFO`

- VUID-VkDeviceMemoryOpaqueCaptureAddressInfo-pNext-pNext
  `pNext` must be `NULL`

- VUID-VkDeviceMemoryOpaqueCaptureAddressInfo-memory-parameter
  `memory` must be a valid VkDeviceMemory handle