[Pkg-libvirt-maintainers] Bug#777138: Simplified steps

[Mathieu Malaterre]

This may be related to:

https://bugzilla.redhat.com/show_bug.cgi?id=1160318#c4

[...]
Jiri Denemark 2014-11-12 11:08:40 EST

So the problem is in the /usr/bin/qemu-kvm wrapper, which runs
qemu-system-x86_64 with -machine accel=kvm to force KVM. When libvirt
starts, it probes QEMU binaries by running them with "-S
-no-user-config -nodefaults -nographic -M none -qmp ... -pidfile ...
-daemonize" to get a dummy process with QMP monitor which we can ask
for available QMP commands, machine types, and lots of other things.
Howver, when qemu-kvm wrapper forces the dummy process to enable KVM,
it fails to start if KVM cannot be enabled for some reason (missing
module, disabled by BIOS, ...). If that happens, we fall back to the
old way of parsing -help, -cpu ?, etc. output. And since we
implemented QMP probing for QEMU 1.2.0, we don't keep up with any
changes made in "-cpu ?" output and thus fail to parse it properly.
But we shouldn't even try to use the old way of probing QEMU
capabilities because we know it's not going to work...
[...]