[Spice-devel] intel vgpu & spice & cursor

[Gerd Hoffmann]

On Thu, 2017-10-12 at 05:42 -0400, Marc-André Lureau wrote:
> Hi
> 
> ----- Original Message -----
> > Hi,
> > 
> > We need to figure a way to handle intel vgpu with spice, especially
> > how
> > to handle the cursor.
> > 
> > What we'll get from the vgpu is two dma-bufs:  One for the primary
> > plane (aka guest display), one for the cursor plane.  We also get
> > the
> > position of the cursor.  We do *not* get the hotspot of the cursor.
> > 
> > The latter implies client mouse mode isn't going to work, so we
> > need
> > some other way to render the cursor.  I see basically two options:
> > 
> 
> It's a shame not to have client mouse mode support. I wonder if we
> could modify the intel driver to pass along the cursor details, like
> virgl does (see drmModeSetCursor2).

Well, physical hardware simply doesn't need to know, so there are no
registers for that.  I think even the kms driver doesn't know where the
hotspot is, only userspace needs that to offset the cursor plane
accordingly.

Notifying the gfx hardware where the hotsplot is is a pure
virtualization thing.  So intel would have to extend the
paravirtualization support in i915 to handle that.  Possible I think,
but requires changes on both host and guest side.

cheers,
  Gerd