So if you try to boot NetBSD inside KVM:
qemu-img create -f qcow2 disk.qcow2 15G wget http://cdn.netbsd.org/pub/NetBSD/NetBSD-7.1/images/NetBSD-7.1-amd64.iso qemu-system-x86_64 -m 2048 -enable-kvm \ -drive if=virtio,file=disk.qcow2,format=qcow2 \ -netdev user,id=mynet0,hostfwd=tcp::7722-:22 \ -device e1000,netdev=mynet0 \ -cdrom NetBSD-7.1-amd64.iso the guest kernel hangs during boot. This works fine for running on real h/w (I assume), and also if you run in TCG by dropping -enable-kvm. It also works if you add -smp 2 -cpu kvm64,-sse2,-cx8 because the bit that causes problems seems to be http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/arch/x86/x86/patch.c?rev=1.2.4.3&content-type=text/x-cvsweb-markup where x86_patch() patches various bits of the guest kernel, and turning off those cpuid features causes it to skip the patching. Any ideas? Does this sound like a KVM bug, or a guest bug? (Tested on 4.4.0-31-generic #50-Ubuntu x86-64 host kernel and QEMU emulator version 2.5.0 (Debian 1:2.5+dfsg-5ubuntu10.8). Yes, I know that's really old...) thanks -- PMM
