Comment 3 for bug 1312199

AFAIK Detecting a not accelerated qemu as hypervisor is not an easy task even on a booted system [1].

When the image is UEC (the kernel image) is separated, nova would be able to pass no_timer_check as kernel parameter.
This is only required when the CONF.libvirt.virt_type=qemu.
Linux automatically turns off the timer_check when the hypervisor is mshyperv and kvm.
AFAIK xen also uses para virtualized clock.
This seams like this is only way to provide stable boot with existing uec images in soft qemu.

Adding nova to this bug for the above change.

Devstack automatically decide when to to use kvm or qemu.
The kvm is selected when the system is able to use hardware acceleration with qemu/kvm.

The cloud image needs to be altered in most cases, when qemu is selected type and the cloud image is not uec in order to use no_timer_check parameter.
This includes the f20 cloud image and all cloud images I saw so far.
It affects the heat-slow jobs.

Adding devstack as affected component for this change.

A Bug for Linux kernel and F20 could image will be created as well.

[1] http://fedorapeople.org/cgit/rjones/public_git/virt-what.git/tree/virt-what.in?id=8aa72773cebbc742d9378fed6b6ac13cb57b0eb3#n228