Comment 8 for bug 1755912

I was able to build it from source. In the first try I was unable to test because it hadn't the spice protocol enabled.

The interface QEMU is using is different, as it has a menu bar with "Machine" and "View" with some options, but I could test and I could reproduce the crash. To clarify, I have recorded the VMs crashing.

Please note I have the notebook screen and a external monitor, so the resolution is a bit strange.

With the command: ./qemu-system-x86_64 -hda ~/Downloads/xubuntu-bionic-desktop-amd64-2018-04-22.iso -m 1536 -vga qxl -enable-kvm -cpu host -smp cpus=2

https://mega.nz/#!98ZiHY5b!ZOaNjb1OaZVj0V80GRjkqafOAL2UinVlAEiTP9aazdk

With the command: ./qemu-system-x86_64 -hda ~/Downloads/xubuntu-bionic-desktop-amd64-2018-04-22.iso -m 1536 -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vram64_size_mb=0,vgamem_mb=16,max_outputs=1,bus=pci.0,addr=0x3 -enable-kvm -cpu host -smp cpus=2

https://mega.nz/#!lwRDRA7I!no-6S6cWxmRf8Q8cjSWfN269PM9DISjLmN7QM6LYBC4

The examples are with Live ISOs, Using -cdrom (the most correct option) instead of -hda still have the same crashes. I can reproduce with a installed VM and with a physical system started in QEMU.

Additional effects I've seen are the guests freezing instead of crashing and a significant RAM memory peak when starting the VM using libvirt. If high amounts of memory are being used in the moment the VM is started, approximately 128 MB of memory goes to SWAP that is never freed. The only way to freed it is to umount the SWAP partition (I tested until SWAP had 658 MB of memory).

What I meant is that with a Bionic host, the guests crash regardless of what the guest is. For now I've tested only with Ubuntu and its derivatives, from 12.04 to 18.04 and they consistently have the issue. I'm downloading CentOS but the download is slow, so it will take some time. I will add the CentOS guest test results after I test it.