[virglrenderer-devel] coherent memory access for virgl

[Gerd Hoffmann]

> Coherence is a property of the mapping.  You can have non-coherent and
> coherent views into the same memory (for example, if
> dma_sync_sg_for_cpu / dma_sync_sg_for_sync is used, ARM display
> drivers can have cached memory).
> 
> Vulkan simplifies this by making it an allocation time property, more
> specifically the memoryIndex in VkMemoryAllocateInfo:
> 
> https://www.khronos.org/registry/vulkan/specs/1.1-extensions/man/html/VkMemoryAllocateInfo.html
> 
> We can do something similar.

Yep, I think it makes sense to make that an object property.

This is where I stand so far:
  https://git.kraxel.org/cgit/linux/log/?h=drm-virtio-ttm

It's not complete yet, host side (qemu) isn't coded yet, and therefore
this is completely untested.  But it should make the direction I'm
heading to clear.

cheers,
  Gerd