Thanks for the clarification Dov.

I've been trying with just "normal" VMs, not SEV. I did already find and try the confidential-containers-demo sev-hashes-v2 branch but it didn't help - not surprising if it's not relevant to normal VMs.

Do you know whether this functionality (-kernel, -initrd, -append options) is actually supposed to work in normal VMs at the moment? The only conditions under which it works here with qemu-6.0.0 is with vUDK2017 & 2018 and an old ovmf binary package from kraxel.og dated 2017. Anything built from the edk2 master branch has failed when using those qemu options, although all the same builds work perfectly using the VMs' internal kernels & initrds. I've also extracted OVMF files from the current kraxel.org package as well as Ubuntu's (hirsute) package and these also fail the same way i.e. kernel boots and initrd works (loads modules) but then the VM filesystem doesn't seem to be found (no /dev/sdX exists to mount the filesystem root).

I guess this could be a qemu problem but since it works with some (old) udk/edk2 versions, I thought I'd look here first.

Thanks for any help or pointers,
chris