From: Fabiano Rosas<farosas@suse.de>
The virt machine has IF_VIRTIO as block_default_type, which causes the
generic code to try to create a virtio-blk-pci device pair at
configure_blockdev()/qemu_create_cli_devices().
Select VIRTIO_BLK and VIRTIO_PCI from CONFIG_ARM_VIRT to avoid errors
when PCI_DEVICES=n (due to e.g. --without-default-devices):
$ ./qemu-system-aarch64 -M virt -accel tcg -cpu max -nodefaults -cdrom foo.qcow2
qemu-system-aarch64: -cdrom foo.qcow2: 'virtio-blk' (alias
'virtio-blk-pci') is not a valid device model name