C Specification

The VkMemoryAllocateInfo structure is defined as:

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

Members

  • sType is the type of this structure.

  • pNext is NULL or a pointer to an extension-specific 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

Description

An instance of the VkMemoryAllocateInfo structure defines a memory import operation if the pNext chain contains an instance of one of the following structures:

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.

When performing a memory import operation, it is the responsibility of the application to ensure the external handles meet all valid usage requirements. However, implementations must perform sufficient validation of external handles 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.

Valid Usage
  • If the pNext chain contains an instance of VkExportMemoryAllocateInfo, 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 contain an instance of VkMemoryDedicatedAllocateInfo or VkDedicatedAllocationMemoryAllocateInfoNV with either its image or buffer field set to a value other than VK_NULL_HANDLE.

  • If the pNext chain contains an instance of VkExportMemoryAllocateInfo, it must not contain an instance of VkExportMemoryAllocateInfoNV or VkExportMemoryWin32HandleInfoNV.

  • If the pNext chain contains an instance of VkImportMemoryWin32HandleInfoKHR, it must not contain an instance of VkImportMemoryWin32HandleInfoNV.

  • 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_KHR, then the values of allocationSize and memoryTypeIndex must match those specified when the memory object being imported was created.

  • 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 that specified when the memory object being imported was allocated.

  • 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 memory was originally allocated.

  • 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.

  • 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_KHR or VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_KMT_BIT_KHR, then the values of allocationSize and memoryTypeIndex must match those specified when the memory object being imported was created.

  • 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 must match the size reported in the memory requirements of the image or buffer member of the instance of VkDedicatedAllocationMemoryAllocateInfoNV included in the pNext chain.

  • 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 external handle was extracted.

  • 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.

  • If the protected memory feature is not enabled, the VkMemoryAllocateInfo::memoryTypeIndex must not indicate a memory type that reports VK_MEMORY_PROPERTY_PROTECTED_BIT.

  • 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

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

  • If the parameters define an import operation and the external handle type is VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BIT_ANDROID:

  • If the parameters do not define an import operation, and the pNext chain contains an instance of VkExportMemoryAllocateInfo with VK_EXTERNAL_MEMORY_HANDLE_TYPE_ANDROID_HARDWARE_BUFFER_BIT_ANDROID included in its handleTypes member, and the pNext contains an instance of VkMemoryDedicatedAllocateInfo with image not equal to VK_NULL_HANDLE, then allocationSize must be 0, otherwise allocationSize must be greater than 0.

  • If the parameters define an import operation, the external handle is an Android hardware buffer, and the pNext chain includes an instance of VkMemoryDedicatedAllocateInfo with image that is not VK_NULL_HANDLE:

    • The Android hardware buffer’s usage must include at least one of AHARDWAREBUFFER_USAGE_GPU_COLOR_OUTPUT or AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE

    • The format of image must be VK_FORMAT_UNDEFINED or the format returned by vkGetAndroidHardwareBufferPropertiesANDROID in VkAndroidHardwareBufferFormatPropertiesANDROID::format for the Android hardware buffer.

    • The width, height, and array layer dimensions of image and the Android hardware buffer must be identical

    • If the Android hardware buffer’s usage includes AHARDWAREBUFFER_USAGE_GPU_MIPMAP_COMPLETE, the image must have ⌊log2(max(width, height))⌋ + 1 mip levels, otherwise it must have exactly 1 mip level.

    • 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 usage

Valid Usage (Implicit)

See Also

Document Notes

For more information, see the Vulkan Specification at URL

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

Copyright (c) 2014-2018 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.