Comment 3 for bug 1710019

Here's the test tool I'm using to verify this. It spins up a zesty guest and gives it time to get past the bootloader and into Linux, then tries to save and restore it.

tar xvfz vm-save-restore.tar.gz
cd vm-save-restore
./setup.sh
./test.sh

I've tested this on an artful host, running the 4.12.0-10.11 kernel from ppa:canonical-kernel-team/unstable and latest upstream QEMU[*] (4.10-rc @ commit 9db6ffc7667673) on both a Cavium ThunderX CRB1S and a Qualcomm QDF2400. Both fail with:

+ sudo virsh define /tmp/tmp.Cx3wyNXijG
Domain 20066-0 defined from /tmp/tmp.Cx3wyNXijG

+ sudo virsh start 20066-0
Domain 20066-0 started

+ sleep 60
+ sudo virsh save 20066-0 /tmp/20066-0.sav

Domain 20066-0 saved to /tmp/20066-0.sav

+ sudo virsh restore /tmp/20066-0.sav
error: Failed to restore domain from /tmp/20066-0.sav
error: operation failed: domain is not running

$ sudo tail -3 /var/log/libvirt/qemu/20066-0.log
Unexpected error in kvm_device_access() at /home/ubuntu/qemu/accel/kvm/kvm-all.c:2229:
2017-08-11T21:33:42.819591Z qemu-system-aarch64: KVM_SET_DEVICE_ATTR failed: Group 4 attr 0x0000000000000002: Invalid argument
2017-08-11 21:33:43.024+0000: shutting down, reason=crashed

[*] Note: you currently need to boot the Ubuntu kernel w/ apparmor=0 to work with latest upstream QEMU