tree 8e5c80d2b3af5248f2fd4ab92198b7376434dfee
parent 02dd733454dd9f817d15233388ab8c35c3a61ead
author Brian Ho <hob@chromium.org> 1574214650 +0000
committer Commit Bot service account <commit-bot@chromium.org> 1574214650 +0000

Create VkImage before importing external memory

This CL is part of a chain of CLs that imports dma-bufs as VkImages
to support WebGPU on Chrome OS.

There are currently two steps for importing external memory into
Vulkan:

  1. DeviceVk::ImportExternalImage: calls into
     MemoryServiceOpaqueFD::ImportMemory which in turn calls into
     vkAllocateMemory and outputs a VkDeviceMemory handle to the
     imported memory.
  2. TextureVk::CreateFromExternal: creates the actual TextureVk
     object, creates the VkImage, and binds the VkDeviceMemory from
     ImportExternalImage to the VkImage.

For dma-buf support, however, we need to re-order these two steps
because importing dma-buf memory requires a handle to the VkImage
that will alias it [1].

This CL splits these two steps into three steps to ensure we create
the VkImage first so we can use it in vkAllocateMemory:

  1. TextureVk::CreateFromExternal: creates the TextureVk and
     VkImage (no longer concerns itself with vkBindImageMemory).
  2. DeviceVk::ImportExternalImage: now takes the VkImage as input
     but is otherwise unchanged.
  3. TextureVk::BindExternalMemory: calls vkBindImageMemory with
     handles to VkDeviceMemory and VkImage.

[1] https://www.khronos.org/registry/vulkan/specs/1.1-extensions/man/html/VkMemoryDedicatedAllocateInfo.html

BUG=chromium:996470

Change-Id: Id2d5951e9b573af79c44ce8c63be5210a279f946
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/13780
Commit-Queue: Brian Ho <hob@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>