I have seen this issue as well, after being pointed to problems booting Xen w/ Ubuntu by a colleague.
To recreate this I did the following: Deployed a server in UEFI mode via MAAS 1.9 using the latest Xenial images from the MAAS daily image stream. After deployment, SSH'd to the server and installed xen-hypervisor-4.6-amd64 via apt-get. Rebooted system after installation of Xen. The system then attempted to EFI PXE (set to do so by default). It successfully PXEd and the MAAS server directed it to boot locally. Then it attempted to boot the Xen Hypervisor and halted at loading the initial ramdisk. At that point, the system abended and rebooted. It was completely unable to boot Xen. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1520979 Title: Grub multiboot is unable to load Xen under EFI To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xen/+bug/1520979/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs