RFC now defines arch code 00:09 for EFI x86-64 (causes ESXi EFI VM's to fail to boot)

If a VM is created in VMWare ESXi and set to boot in EFI mode, it will be unable to boot from MAAS as MASS serves the VM a non-EFI compatible bootloader.

This is because the VM reports a PXE architecture of 00009, as confirmed by running a packet capture and examining the DHCP request from the VM. However, MAAS currently serves up bootloaders as per the following arch as reported by the client;

0: pxelinux.0 (legacy BIOS)
7: bootx64.efi (EFI x64)
B: grubaa64.efi (ARM x64)
E: pxelinux.0 (powernv)

If no match is found, pxelinux.0 is served.

Reading around, PXEClient:Arch:00009 is used by VMWare to signify either EFI 32 or 64 bit.

To fix this, I edited /var/lib/maas/dhcpd.conf to add the following entry before the final else case in the bootloader section;

} elsif option arch = 00:09 {
    # uefi_amd64
    filename "bootx64.efi";

After restarting maas-dhcpd and restarting the VM, it successfully booted from MAAS and ran the commissioning tasks. However, I don't know how persistent this fix will be given that dhcpd.conf is managed by MAAS.

Would it be possible to persistently add a the lines above to MAAS's DHCP configuration?

MaaS: 2.4.0-beta2
MaaS Host: Ubuntu 18.04 LTS
ESXi: 6.5.0 Update 1 (Build 7388607)