Justin
Don't have one handy - and they aren't visible except to the close eye of a few pixels in width. BUT...you can go fullscreen, and notice that the cursor on the window edge changes - and the center icons of VMM that get you out of fullscreen are difficult to get at. Then interogate X and you will find that you are not at the native resolution of the host's monitor.
In case it's a graphics issue - I am on an AMD RX-480 using the opensource drivers. I also installed the spice-vdagent and the xf86-qxl video drivers. and of course started the appropriate daemons.
One more item - the issue does not happen with VirtualBox and the CTRL+F keysequence. The issue is unique to KVM and Virt-Manager. Also happens in Virt-Viewer.
Dave
PS: Said better - I don't have Solus on real hardware at the moment. I have temped in Manjaro Cinnamon. And as I hinted at - there is nothing to see anyway. You have to interrogate "X" to see the diff between the VM's resolution and the host resolution. And as Virt-Manager scales the VM - things get a tad blurry.