+++ This bug was initially created as a clone of Bug #1066145 +++

Description of problem:

[Same thing happens on ppc64]

qemu-system-ppc64 has an annoying bug since forever where the -help
output mentioned -no-hpet, but if you actually use this flag, qemu
helpfully prints:

  Option no-hpet not supported for this target

If you use the libvirt XML on an POWER 7 guest:

  <timer name=hpet present=no>

meaning "don't include an HPET device", then libvirt adds -no-hpet
to the command line, and qemu-system-arm won't start up.

I have worked around this in libguestfs by not including this
XML fragment on ppc64, but this still looks like it is a bug in
libvirt (and qemu of course).

Version-Release number of selected component (if applicable):

libvirt from git today

How reproducible:

100%

Steps to Reproduce:
1. Compile libvirt from git on POWER.
2. Run: ~/d/libvirt/run libguestfs-test-tool

Actual results:

LC_ALL=C PATH=/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/rjones/.local/bin:/home/rjones/bin HOME=/home/rjones USER=rjones LOGNAME=rjones QEMU_AUDIO_DRV=none TMPDIR=/var/tmp /usr/bin/qemu-system-ppc64 -name guestfs-6iushxm648pz1e3q -S -machine pseries,accel=tcg,usb=off -m 768 -realtime mlock=off -smp 1,sockets=1,cores=1,threads=1 -uuid 92e4cbb4-bd61-4efa-b47c-1f22fe2f4145 -nographic -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/home/rjones/.config/libvirt/qemu/lib/guestfs-6iushxm648pz1e3q.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew -no-hpet -no-reboot -kernel /var/tmp/.guestfs-1005/kernel.6807 -initrd /var/tmp/.guestfs-1005/initrd.6807 -append panic=1 console=ttyS0 udevtimeout=600 no_timer_check acpi=off printk.time=1 cgroup_disable=memory root=/dev/sdb selinux=0 guestfs_verbose=1 TERM=xterm-256color -device virtio-scsi-pci,id=scsi0,bus=pci,addr=0x1 -device virtio-serial-pci,id=virtio-serial0,bus=pci,addr=0x3 -usb -drive file=/tmp/libguestfszJaaPR/scratch.1,if=none,id=drive-scsi0-0-0-0,format=raw,cache=unsafe -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1 -drive file=/tmp/libguestfszJaaPR/overlay2,if=none,id=drive-scsi0-0-1-0,format=qcow2,cache=unsafe -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=1,lun=0,drive=drive-scsi0-0-1-0,id=scsi0-0-1-0 -chardev socket,id=charserial0,path=/tmp/libguestfszJaaPR/console.sock -device spapr-vty,chardev=charserial0,reg=0x30000000 -chardev socket,id=charchannel0,path=/tmp/libguestfszJaaPR/guestfsd.sock -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.libguestfs.channel.0 -device virtio-balloon-pci,id=balloon0,bus=pci,addr=0x4
Domain id=2 is tainted: custom-argv
Option no-hpet not supported for this target

Expected results:

Should probably ignore this.

Additional info: