Re: [Qemu-devel] [PATCH] move 'unsafe' to end of caching modes in help

[Avi Kivity]

 On 07/26/2010 10:35 PM, Anthony Liguori wrote:
> > > > If you want libvirt to do the right thing, provide a proper 
> > > > capabilities interface.  Using the version has its downsides as 
> > > > much as the help text.
> > >
> > > That's simply not the case.  Please, provide an actual example where 
> > > version is not reliable and backports aren't trivially easy to detect.
> >
> >
> > t=0 starting point, cache=unsafe is unknown
> > t=1 qemu upstream adds cache=unknown
> > t=2 libvirt adds support for cache=unsafe, releases
> > t=3 evil distro backports cache=unsafe, releases qemu-kvm-1.2.3.4
> > t=4 user tries libvirt from t=2 with qemu from t=3, cache=unsafe not 
> > detected
> >
> > version numbers force a libvirt update every time a feature is 
> > backported.
>
> That's a bogus scenario because said evil distro would also enhance 
> libvirt to detect the feature properly.

That means a new libvirt release is needed.

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.