Comment 0 for bug 1673564

This is a followup of an earlier thread/bug that we have narrowed down to an incompatibility/issue with vhost support in qemu-efi. Without vhost=on qemu seems to be working fine.

I have tested several edk2 firmwares:
- xenial
- zesty
- Fedora: ftp://195.220.108.108/linux/fedora-secondary/development/rawhide/Everything/aarch64/os/Packages/e/edk2-aarch64-20170209git296153c5-2.fc26.noarch.rpm

I have also tested with different guests:
- cirros: https://download.cirros-cloud.net/daily/20161201/cirros-d161201-aarch64-disk.img
- ubuntu xenial: https://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-arm64-uefi1.img

The test steps are simple enough. A tap device is needed, qemu-kvm, qemu-efi need to be installed. The UEFI iamge is run as shown in the launch.sh script, the tap device is used in vhost=on mode.

Also note that the QEMU_EFI.fd binary needs to be padded up to 64M:
dd if=/dev/zero of=AAVMF_CODE.fd bs=1M count=64
dd if=QEMU_EFI.fd of=AAVMF_CODE.fd conv=notrunc

The result was always the same, the node crashing with soft-lockups when qemu was attempting to boot the kernel.

I will attach all the relevant information shortly.