C Specification

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:

typedef struct VkImportMemoryHostPointerInfoEXT {
    VkStructureType                       sType;
    const void*                           pNext;
    VkExternalMemoryHandleTypeFlagBits    handleType;
    void*                                 pHostPointer;
} VkImportMemoryHostPointerInfoEXT;

Members

  • sType is the type of this structure.

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

  • handleType specifies the handle type.

  • pHostPointer is the host pointer to import from.

Description

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 underlying memory as defined in Host Access to Device Memory Objects.

Applications can import the same underlying memory into multiple instances of Vulkan and multiple times into a given Vulkan instance. However, implementations may fail to import the same underlying memory 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.

The application must ensure that the imported memory range remains valid and accessible for the lifetime of the imported memory object.

Valid Usage
  • If handleType is not 0, it must be supported for import, as reported in VkExternalMemoryProperties

  • 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

  • pHostPointer must be a pointer aligned to an integer multiple of VkPhysicalDeviceExternalMemoryHostPropertiesEXT::minImportedHostPointerAlignment

  • 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

  • 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)

See Also

Document Notes

For more information, see the Vulkan Specification

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

Copyright (c) 2014-2019 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.