Comment 63 for bug 1865515

I was told that the latest SHIM/GRUB from Hirsute may have fixed this issue. It looks like chain loading from network GRUB to local GRUB works but the VM turns off when it tries to start the kernel. Attached is GRUB output with debug="all"

My test setup is as follows:
grub over the network and local: 2.04-1ubuntu45
shim over the network and local: 1.46+15.4-0ubuntu1
OS: Ubuntu 21.04
Machine: LXD VM 4.0.5
qemu command: /snap/lxd/19647/bin/qemu-system-x86_64 -S -name lxd-vm -uuid f5fec2be-21c7-4ffb-847f-f88589c06686 -daemonize -cpu host -nographic -serial chardev:console -nodefaults -no-reboot -no-user-config -sandbox on,obsolete=deny,elevateprivileges=allow,spawn=deny,resourcecontrol=deny -readconfig /var/snap/lxd/common/lxd/logs/maas_lxd-vm/qemu.conf -pidfile /var/snap/lxd/common/lxd/logs/maas_lxd-vm/qemu.pid -D /var/snap/lxd/common/lxd/logs/maas_lxd-vm/qemu.log -chroot /var/snap/lxd/common/lxd/virtual-machines/maas_lxd-vm -smbios type=2,manufacturer=Canonical Ltd.,product=LXD -runas lxd