Re: [BUG][v6.9-rc6] Deadlock with: Revert "drm/qxl: simplify qxl_fence_wait"

[Timo Lindfors <timo.lindfors@iki.fi>]

On Tue, 7 May 2024, Gerd Hoffmann wrote:
> Worth trying: use vnc.  The qemu vnc server will skip updates when the
> network pipeline is full.  That throttles the frame rate, but also
> reduces the display update latency.

With Debian 12 it seems that the virtio + vnc + firefox combination 
results in a black firefox window. Adding MOZ_ENABLE_WAYLAND=1 makes
the browser visible but I still see the constant redraw behavior when scrolling.

The qxl + spice + firefox combination scrolls smoothly even if I force 
firefox to use wayland. I suppose I could write a more synthetic test if
it would be useful? With systemtap I can trace what happens during a single
scroll event.

> In general the trend seems to be to move to in-guest remote desktop
> solutions.  Do NOT make VMs a special case with a special solution,
> instead handle VMs like bare metal.  Commercial solutions exist for a
> while, some of them are doing hardware-assisted video encoding to send
> the display as video stream to the remote end.  gnome+rdp is a new
> player here, clearly worth a try.

Yes this makes sense. I'm definitely not trying to stick to a particular 
technology but instead try to find the best FOSS solution for the use case 
of hosting linux desktops on a server.

-Timo