tree 320de3ad0ef13c1fccec083a0cd5f171fc7084bf
parent 6139da6efebdc7d5a869eacd53ec49099952683e
author Gurchetan Singh <gurchetansingh@chromium.org> 1612829371 -0800
committer Commit Bot <commit-bot@chromium.org> 1618509505 +0000

rutabaga_gfx: cross-process Vulkan mappings

In multi-process mode, we currently rely on dma-buf mmap() to
map GPU buffers into the guest.  We usually have to fix the
Mesa driver, and maybe even the kernel to get to work.  That's
"kind of" fine for ChromeOS, which owns the entire stack.

For their Virtual Graphics Interface (VGI) initiative, Android
upstream has requested multi-process mode to work in a
cross-platform, generic way.  Using Vulkan is the only option
that meets the rigorous, uncompromising, strict, meticulous and
bone-crushing requirements of Android upstream.

This has possible two benefits:
  1) We can enable multi-process mode on Nvidia or other
     closed-source drivers, which is nice for Cuttlefish.

  2) On open-source drivers, dma-buf memory is pinned to the
     GTT (amdgpu), even when ideally it can be moved into faster
     vram regions.  This atleast gives the implementation the
     chance to do the smarter and faster option.

We shouldn't run into any SELinux issues since the main crosvm
process is not sandboxed.

Incidentals:
   * Changes vulkano_gralloc to consider integrated GPUs and dGPUs.
     Metadata query is preferred done on the integrated GPU.
   * Update vulkano_gralloc to match top of tree vulkano.

BUG=b:173630595
TEST=used Vulkano allocator and mapped memory into the guest

Change-Id: I78b069c7478d11b3201397894dcccd13bdc61f2c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2792042
Tested-by: Gurchetan Singh <gurchetansingh@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Gurchetan Singh <gurchetansingh@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>