61 lines
2.1 KiB
Plaintext
61 lines
2.1 KiB
Plaintext
include::meta/VK_EXT_external_memory_dma_buf.txt[]
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*Last Modified Date*::
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2017-10-10
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*IP Status*::
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No known IP claims.
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*Contributors*::
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- Chad Versace, Google
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- James Jones, NVIDIA
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- Jason Ekstrand, Intel
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A dma_buf is a type of file descriptor, defined by the Linux kernel, that
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allows sharing memory across kernel device drivers and across processes.
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This extension enables applications to import a dma_buf as
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slink:VkDeviceMemory; to export slink:VkDeviceMemory as a dma_buf; and to
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create slink:VkBuffer objects that can: be bound to that memory.
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=== New Enum Constants
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* Extending elink:VkExternalMemoryHandleTypeFlagBitsKHR:
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** ename:VK_EXTERNAL_MEMORY_HANDLE_TYPE_DMA_BUF_BIT_EXT
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=== Issues
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1.
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How does the application, when creating a slink:VkImage that it intends
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to bind to dma_buf slink:VkDeviceMemory that contains an externally
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produced image, specify the memory layout (such as row pitch and DRM
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format modifier) of the slink:VkImage? In other words, how does the
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application achieve behavior comparable to that provided by
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https://www.khronos.org/registry/EGL/extensions/EXT/EGL_EXT_image_dma_buf_import.txt[EGL_EXT_image_dma_buf_import]
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and
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https://www.khronos.org/registry/EGL/extensions/EXT/EGL_EXT_image_dma_buf_import_modifiers.txt[EGL_EXT_image_dma_buf_import_modifiers]?
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+
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--
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*RESOLVED*.
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Features comparable to those in
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https://www.khronos.org/registry/EGL/extensions/EXT/EGL_EXT_image_dma_buf_import.txt[EGL_EXT_image_dma_buf_import]
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and
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https://www.khronos.org/registry/EGL/extensions/EXT/EGL_EXT_image_dma_buf_import_modifiers.txt[EGL_EXT_image_dma_buf_import_modifiers]
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will be provided by an extension layered atop this one.
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--
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2.
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Without the ability to specify the memory layout of external dma_buf
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images, how is this extension useful?
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+
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--
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*RESOLVED*.
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This extension provides exactly one new feature: the ability to
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import/export between dma_bufs and slink:VkDeviceMemory.
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This feature, together with features provided by
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`<<VK_KHR_external_memory_fd>>`, is sufficient to bind a slink:VkBuffer to
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dma_buf.
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--
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=== Version History
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* Revision 1, 2017-10-10 (Chad Versace)
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- Squashed internal revisions
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