Our test data used a lot of different qemu binary paths and some
of them were based on downstream systems.
Note that there is one file where I had to add "accel=kvm" because
the qemuargv2xml code parses "/usr/bin/kvm" as virt type="kvm".
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Previously we added a set of EHCI+UHCI controllers to Q35 machines to
mimic real hardware as closely as possible, but recent discussions
have pointed out that the nec-usb-xhci (USB3) controller is much more
virtualization-friendly (uses less CPU), so this patch switches the
default for Q35 machinetypes to add an XHCI instead (if it's
supported, which it of course *will* be).
Since none of the existing test cases left out USB controllers in the
input XML, a new Q35 test case was added which has *no* devices, so
ends up with only the defaults always put in by qemu, plus those added
by libvirt.
