Re: [Qemu-devel] [PATCH] opengl rendering in the sdl window

[Gerd Hoffmann <kraxel@redhat.com>]

Jamie Lokier wrote:
> Gerd Hoffmann wrote:
>> Or use the monitor, which the gui needs anyway to implement the nice
>> control buttons for the user.  Which would it make easier to re-attach
>> the gui to the vm as all you need to know is where the monitor is ...
> 
> You want to transmit the image or the image-blit-please protocol over
> the monitor connection?

Negotiate a shared memory segment somehow, then send just notifications.
Have to think about how to to that in detail, ideally this would be a
shared memory segment shared by all three instances involved: the gui
process, the qemu process and the X-Server.  So qemu can render directly
into a XShmImage, although it has no (direct) connection to the X-Server.

> I think the monitor would need a few
> improvements before it could do that well.

Sure, we'll need (a) multiple connections at the same time and (b) some
"select <eventtype>" command for async notify for that.  I think they
will come anyway for several other reasons.

> A nice thing about VNC-SHM would be the GUI could run on a different
> machine to the emulator (SHM not used then), since it only needs VNC
> and monitor, which can both be remote.

For the remote case it certainly doesn't make sense to reinvent VNC.
But you'll probably use some management layer like libvirt anyway then,
ssh'ing into the remote machine for starting / stopping VM's isn't very
handy.

I'm targeting the local desktop use case.  But maybe vnc +
shmem-extention works equally well here.

cheers,
  Gerd