Hi all, I also encountered this problem. This is my first time trying out Xen, could only get HVM to boot with Seabios, not with OVMF.
On Debian 12 Bookworm Non-functional package version: 2022.11-6+deb12u1 As already mentioned here, reverting to package version: 2020.11-2+deb11u2 solved the problem, the HVMs boots as expected. I also had success building upstream OVMF from source, branch 'stable/202408' , like so: OvmfPkg/build.sh -a X64 -b RELEASE -p OvmfPkg/OvmfXen.dsc and placing it in /usr/share/ovmf/ on the Xen-host, the HVMs boots as expected. We probably need something like `/usr/share/ovmf/XEN_OVMF.fd` built from OvmfXen, and also need to set the configure options for the xen-hypervisor package to `--with-system-ovmf=/usr/share/ovmf/XEN_OVMF.fd`. On the other hand, /usr/share/doc/ovmf/README.Debian mentions that OVMF.fd(the unified image) is for backwards compatibility, the best way is to have a shared OVMF_CODE.fd and per-vm OVMF_VARS.fd, however I don't think you can use the vars with xl.
