[Spice-devel] RFC: Integrating Virgil and Spice

[Dave Airlie]

On Wed, Oct 9, 2013 at 3:36 PM, Steven Newbury <steve at snewbury.org.uk> wrote:
> On Tue,  8 Oct 2013, 23:51:13 BST, Dave Airlie <airlied at gmail.com> wrote:
>>
>> That would be the local rendering solution I think we'd prefer,
>>
>> qemu runs as qemu user, uses EGL to talk to the drm render-nodes,
>> has some sort of unix socket that the viewer connects to and can hand
>> fds across, then the client viewer uses EGL or GLX to render on-screen
>> and import the handles into EGL and displays the contents, there may
>> be a small bit of sync info to send across.
>>
>> For remoting then we'd have an extra readback (slow) from the GPU and
>> then spice or vnc encoding stages.
> For the non-local case wouldn't it be possible to have the GPU render
> directly to a shared buffer in system RAM rather than to the GPU memory and
> reading back?

No that generally is a really bad idea, since things like blending
involve reading back from the video ram,
and it would generally end up being worse for framerates than reading back.

Dave.