[libvirt] [RFC] Question regarding the validity of QEMU capabilities

[Jiri Denemark]

On Fri, Oct 20, 2017 at 13:15:41 +0200, Marc Hartmayer wrote:
> On Fri, Oct 20, 2017 at 01:10 PM +0200, Pavel Hrdina <phrdina at redhat.com> wrote:
> > On Fri, Oct 20, 2017 at 12:59:51PM +0200, Marc Hartmayer wrote:
> >> Hi all,
> >>
> >> the actual capabilities of QEMU are depending on the host. This
> >> includes dependencies like which kernel modules are loaded or which
> >> kernel parameters are used (e.g. kvm.nested). Therefore, after a
> >> restart we cannot be sure that the QEMU capabilities remain the same.
> >>
> >> How can we solve this problem?
> >
> > Hi,
> >
> > thanks for bringing up this issue, we kind of already know about it
> > but it's good idea to discuss it publicly.
> >
> >>
> >> I have come up with two ways:
> >>  - reprobe the capabilities with every host reboot
> >
> > This is the solution that was agreed on but nobody was motivated enough
> > to write the code :).
> 
> First - thank you for the quick answer :)
> 
> Would it be okay if the solution depends on systemd?

Not really. It may of course use systemd if it's present, but it should
work even on systems without systemd.

Jirka