Re: [PATCH 0/3] ui/gtk: introducing vc->visible

[Marc-André Lureau]

Hi

On Fri, Mar 8, 2024 at 4:59 AM Kim, Dongwon <dongwon.kim@intel.com> wrote:
>
> Hi Marc-André,
>
> > -----Original Message-----
> > From: Marc-André Lureau <marcandre.lureau@redhat.com>
> > Sent: Tuesday, March 5, 2024 4:18 AM
> > To: Kim, Dongwon <dongwon.kim@intel.com>; P. Berrange, Daniel
> > <berrange@redhat.com>
> > Cc: qemu-devel@nongnu.org
> > Subject: Re: [PATCH 0/3] ui/gtk: introducing vc->visible
> >
> > Hi Kim
> >
> > I am uncomfortable with the series in general.
> >
> > Not only we don't have the means to draw dmabuf/scanout "when required", so
> > resuming drawing won't work until the guest draws (this is already a 
> > problem but
> [Kim, Dongwon] Yes, this is right. The display won't be updated until there 
> is a new frame submitted.
> > you are only making it worse). And I also think reconfiguring the guest by 
> > merely
> > minimizing or switching window/tabs isn't what most users would expect.
> [Kim, Dongwon] I understand your concern. Then what do you suggest I need to 
> do or look into to avoid the situation where the host rendering of the guest 
> frame is scheduled but pending due to tab switching or minimization of window 
> as the guest (virtio-gpu drv) is waiting for the response to move on to the 
> next frame? Do you think the frame update should just continue on the host 
> side regardless of visibility of the window? (If this is the standard 
> expectation, then one of our Linux configuration - Yocto + ICE WM has some 
> bug in it.)
>


Given that we can't pause/resume the drawing, I think it's best to
always draw regardless of the visibility. If GTK doesn't draw when
minimized or hidden, we should find a way to "force" that.


> >
> > (fwiw, my personal opinion is that QEMU shouldn't provide UIs and different
> > clients should be able to implement different behaviours, out of process.. 
> > that
> > makes me relatively less motivated to break things and be responsible)
> >
> > Daniel, could you have a look too?
> >
> > thanks
> >
> > On Fri, Mar 1, 2024 at 4:05 AM Kim, Dongwon <dongwon.kim@intel.com>
> > wrote:
> > >
> > > Hi Marc-André Lureau,
> > >
> > > Just a reminder.. I need your help reviewing this patch series. Please
> > > take a look at my messages at
> > > https://lists.gnu.org/archive/html/qemu-devel/2024-01/msg06636.html
> > > and
> > > https://lists.gnu.org/archive/html/qemu-devel/2024-01/msg06637.html
> > >
> > > Thanks!!
> > > DW
> > >
> > > > -----Original Message-----
> > > > From: qemu-devel-bounces+dongwon.kim=intel.com@nongnu.org <qemu-
> > > > devel-bounces+dongwon.kim=intel.com@nongnu.org> On Behalf Of
> > > > dongwon.kim@intel.com
> > > > Sent: Tuesday, January 30, 2024 3:49 PM
> > > > To: qemu-devel@nongnu.org
> > > > Subject: [PATCH 0/3] ui/gtk: introducing vc->visible
> > > >
> > > > From: Dongwon Kim <dongwon.kim@intel.com>
> > > >
> > > > Drawing guest display frames can't be completed while the VC is not
> > > > in visible state, which could result in timeout in both the host and
> > > > the guest especially when using blob scanout. Therefore it is needed
> > > > to update and track the visiblity status of the VC and unblock the 
> > > > pipeline in
> > case when VC becomes invisible (e.g.
> > > > windows minimization, switching among tabs) while processing a guest
> > frame.
> > > >
> > > > First patch (0001-ui-gtk-skip...) is introducing a flag 'visible' to
> > > > VirtualConsole struct then set it only if the VC and its window is 
> > > > visible.
> > > >
> > > > Second patch (0002-ui-gtk-set-...) sets the ui size to 0 when VC is
> > > > invisible when the tab is closed or deactivated. This notifies the
> > > > guest that the associated guest display is not active anymore.
> > > >
> > > > Third patch (0003-ui-gtk-reset-visible...) adds a callback for GTK
> > > > window-state- event. The flag, 'visible' is updated based on the 
> > > > minization
> > status of the window.
> > > >
> > > > Dongwon Kim (3):
> > > >   ui/gtk: skip drawing guest scanout when associated VC is invisible
> > > >   ui/gtk: set the ui size to 0 when invisible
> > > >   ui/gtk: reset visible flag when window is minimized
> > > >
> > > >  include/ui/gtk.h |  1 +
> > > >  ui/gtk-egl.c     |  8 +++++++
> > > >  ui/gtk-gl-area.c |  8 +++++++
> > > >  ui/gtk.c         | 62 ++++++++++++++++++++++++++++++++++++++++++++++--
> > > >  4 files changed, 77 insertions(+), 2 deletions(-)
> > > >
> > > > --
> > > > 2.34.1
> > > >
> > >
>


-- 
Marc-André Lureau