This comes from:

https://bugzilla.redhat.com/show_bug.cgi?id=969416#c5

> Vojtech reported this bug on my request. I think the answer depends on
> whether virt-manager will (in the new version) intelligently update the
> window size when guest resolution changes.
> 
> Because I really like what VirtualBox does:
> 1. It matches window size to guest resolution on startup.
> 2. It changes window size to guest resolution on every resolution change,
> unless it's maximized or fullscreen.
> 3. If you have additions installed, it changes guest resolution to match
> your window size.
> 4. It has keyboard shortcuts, which work and don't override guest shortcuts
> at the same time. I can use it the match window size easily, if needed.
> 
> Compared to virt-manager:
> 1. I have a wrong window size on every single startup. It's cased by my
> secondary small screen. (Reported also here, might be a gnome-shell bug:
> https://bugzilla.gnome.org/show_bug.cgi?id=707378 )
> 2. The window size is not adjusted to guest resolution on any resolution
> change.
> 3. The guest resolution is not matched to window size, even though we
> control our full software stack.
> 4. Keyboard shortcuts are not available (overriding the guest ones is not an
> option for me).
> ===> I need to dig deep in the menu (using the mouse) to match window size
> to guest resolution on _every_ VM startup (and I start a lot of VMs during
> my usual work day).
> 
> In addition, I'm forced to use scale=always, because on my 12" notebook
> screen (1366x768) the window with a default Fedora guest simply does not
> fit. Unfortunately, as a result, if I move the window to a large screen (I
> dock the notebook, FullHD), the contents in scaled up a lot and everything
> is just huge, especially when I switch into guest's VT (I do that also a
> lot).
> 
> So, I'm constantly shuffling with window sizes and digging deep in the menus
> to trigger resize-to-vm. And I'm very unhappy about this.
> 
> Having a new option scaling=if-larger would help me, because it would apply
> to me 12" screen (too small even when maximized), but it wouldn't apply to
> my large screen (I also use maximized windows there to avoid all the fuss
> with changing window sizes) and so I wouldn't see gigantic console letters
> in there.
> 
> If you don't want to implement it, but still improve the quality of life for
> some of us:) , I suggest:
> 1. Make the resize-to-vm action more accessible. Possible ways:
> a) Put it into the action bar at the top of the window, next to
> switch-fullscreen button.
> b) Implement keyboard shortcuts that don't override guest shortcuts.
> VirtualBox's "Host" key style is very nice.
> 
> 2. Make resize-to-vm action less needed:
> a) Set a correct window size on start (might not be your bug, but gtk/gnome
> bug, but I'm unable to debug that)
> b) change guest resolution on window size change
> c) or autofit window size on resolution change (and in case you can't
> autofit the window, because the screen is too small, automatically enable
> scaling)
> 
> Thanks. I'd happy to provide any details you need that I haven't covered in
> this reply, just tell me.


We need to take a look at what virtualbox, vmware workstation/player, boxes, and virt-viewer WRT display handling, and try to come up with a plan that's best for virt-manager.

At the very least I expect we will:

- Change 'scaling' to just be a boolean on/off option
- Consider enabling scaling by default
- Consider enabling resize-guest by default
- Make sure that an initial run of a VM resizes to new resolutions correctly.

The difficulty is that we have a lot of variables to handle: spice or vnc, agent or none (or not supported), do we ever want to have scrollbars?, do we want to remember the resolution a user manually resized their window to?, etc.