I have previously used a Ubuntu 26.04 amd64 host system to install a RHEL10
s390x guest with no problem.
Also when trying to do the install using a command such as
qemu-system-s390x -M s390-ccw-virtio \
-monitor stdio \
-name "guest" \
-m 4096 \
-mem-prealloc \
-kernel /home/tjcw/Downloads/dvd1/linux_vm \
-initrd /home/tjcw/Downloads/dvd1/root.bin \
-blockdev
file,node-name=c1,filename=/home/tjcw/Downloads/debian-13.4.0-s390x-DVD-1.iso
\
-device virtio-scsi \
-device scsi-cd,drive=c1 \
-netdev user,id=net0,hostfwd=tcp::2222-:22 \
-device virtio-net-ccw,netdev=net0,id=net0_dev \
-drive
file=/home/tjcw/VMs/s390x-vm.qcow2,format=qcow2,if=none,id=drive-sata0-0-0 \
-device virtio-blk-pci,drive=drive-sata0-0-0,id=sata0-0-0
(on a debian trixie system) I could boot linux and get as far as running
the installer if I uses explicit kernel and initrd as above, but the
corresponding command attempting to use the kernel and ramdisk in the
'.iso' would not boot.
I wasn't able to do the install with 'qemu-system-s390x' because I could
not get networking to work correctly.
