Story time! When I was working on my virtual environment, I rebooted my main desktop. So I was stuck using my Windows desktop for a minute, and I wanted to work on my virtual machines.
I decided to do some X forwarding, which for virt-manager on CentOS 7 needs some special steps.
On the server
The first thing is to install virt-manager. You also will need a piece of software named xauth, and some special fonts.
yum install -y virt-manager xauth dejavu-\*fonts
On the client
On the Windows client, you should install an X server. I picked Xming. It also needs it fonts installed.
Connect to server with PuTTY. You will need to configure PuTTY to allow X forwarding, and to use the right X server.
Unfortunately, my keyboard input to the virtual machine does not work when I have it configured with a spice display. But it works when I use a vnc display. See https://bugzilla.redhat.com/show_bug.cgi?id=1236412 for a closed bug report that has similar symptoms to this problem.
- PuTTY https://www.chiark.greenend.org.uk/~sgtatham/putty/