Dear list, I have moved my HVMs from xen to kvm and it worked well except some problems using virsh. First, one OpenSolaris HVM does boot with warnings: WARNING: /pci@0,0/pci1af4,1100@1,2 (uhci1): No SOF interrupts have been received, this USB UHCI host controller is unusable* *The corresponding process: /usr/bin/qemu-system-x86_64 -S -M pc-0.12 -enable-kvm -m 1024 -smp 1,sockets=1,cores=1,threads=1 \ -name server01 -uuid e382c360-23bd-b400-0b89-9a1e69613ec4 -nographic \ -nodefaults -chardev socket,id=monitor,path=/usr/local/libvirt/var/lib/libvirt/qemu/server01.monitor,server,nowait \ -mon chardev=monitor,mode=readline -rtc base=utc -boot c -drive file=/dev/xen_vol/xen_opensol,if=none,id=drive-ide0-0-0,boot=on \ -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 -drive file=/dev/hde,if=none,id=drive-ide0-0-1 \ -device ide-drive,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 -device rtl8139,vlan=0,id=net0,mac=00:16:3e:28:85:7a,bus=pci.0,addr=0x4 \ -net tap,ifname=tap0,vlan=0,name=hostnet0 -chardev pty,id=serial0 -device isa-serial,chardev=serial0 -usb -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 This does not happen when I boot with plain qemu-bin: /usr/local/kvm/bin/qemu-system-x86_64 -hda /dev/xen_vol/xen_opensol \ -hdb /dev/hde -net nic,macaddr=00:16:3e:28:85:7a \ -net tap,ifname=tap0 -nographic \ -m 1024 -daemonize Second is one Centos 5.2 HVM that does not boot at all. However when I boot manually and omitt "-S" and "-nodefaults" then it comes up. I looked for the -S option and I wonder why it is being used by default. Can anybody help me? I cannot see any further documentation about the "-nodefault" option and how to disable "-S" Best regards Ralf