I am having great success running FreeBSD's Xorg installed via pkg on a FreeBSD guest VM, on a Linux host running KVM/Qemu with libvirt. The old workaround of recompiling the guest's Xorg with gcc no longer is needed.
The key is to make sure you use a UEFI guest machine, you can press escape on the guest bios and set the resolution that the machine will use, I have used 1360x768 and 1600x900 without issue, as well as make sure you install the xf86-video-scfb driver, and I had to steal an /etc/X11/xorg.conf from trueOS.
The key is to make sure you use a UEFI guest machine, you can press escape on the guest bios and set the resolution that the machine will use, I have used 1360x768 and 1600x900 without issue, as well as make sure you install the xf86-video-scfb driver, and I had to steal an /etc/X11/xorg.conf from trueOS.