Getting X11 to run on OS X via xQuartz is a fairly painless process. You just have to download it from here and install it.
There is no virt-manager native equivalent for OS X so the best way is to run X over SSH and remotely access virt-manager. However there are a couple of gotchas that I experienced as the remote linux server I was accessing needed a few more packages to make this work.
Enable Remote Access to Virt-Manager via an OS X Machine
Install xauthWhen connecting to a remote server via ssh with the -X option, the following error is displayed:
X11 forwarding request failed on channel 0
To resolve this install xauth:
[root@host ~]# yum -y install xorg-x11-xauth
Install FontsVirt-Manager is a X application which is capable to manage RHEL's XEN, QEMU/KVM, LXC service. Similar to other X application, it could be launched remotely via X11 Forwarding.
However, it happens that garbage fonts will be shown if the host is not installed with appropriate font package. To fix this, package dejavu-lgc-sans-fonts have to be installed.
[root@host ~]# yum -y install dejavu-lgc-sans-fonts