[RFC PATCH v2 0/3] drm/i915/gvt: Enable vGPU local display direct flip

[Gerd Hoffmann]

  Hi,

> In-kernel direct flip:
> ----------------------
> With "enable_direct_flip" switched on, during vGPU page flip, GVT-g will:
> 
> 1) Find out the assigned HW planes.
> GVT-g is the owner of the I915_GEM_OBJECT_IS_PROXY GEM which is exposed by
> GVT-g with dma-buf interface. 
> 
> GVT-g scan the framebuffers set on the active planes to see if there are some
> framebuffers with I915_GEM_OBJECT_IS_PROXY GEM.
> 
> A HW plane using a framebuffer with I915_GEM_OBJECT_IS_PROXY GEM is considered
> as an assigned plane. GVT-g gets the assignment information through gvt_info
> structure of the I915_GEM_OBJECT_IS_PROXY GEM.
> 
> 2) Decode vGPU's framebuffer info and use that to update the shadow framebuffer.
> 
> 3) Commit the shadow framebuffer through "drm_atomic_commit()".

Hmm, no userspace API included in this patch series.

The qemu branch has an patch (vfio/display: Interface of querying
the fb id of vGPU's plane) which isn't documented.

What is the plan here?

cheers,
  Gerd