[libvirt] [PATCH] qemu: don't refuse to undefine a guest with NVRAM file

Daniel P. Berrange berrange at redhat.com
Tue Feb 24 15:54:24 UTC 2015


On Tue, Feb 24, 2015 at 04:41:44PM +0100, Peter Krempa wrote:
> On Tue, Feb 24, 2015 at 15:31:14 +0000, Daniel Berrange wrote:
> > On Tue, Feb 24, 2015 at 04:23:41PM +0100, Peter Krempa wrote:
> > > The original motivation is apparently that we should not allow anything
> > > that would represent state of the deleted VM to be transferred
> > > accidentaly to a new VM with same name. For the save image or snapshots
> > > the risk of persisting any data is low as a save image would not
> > > function without it's disk and still be somewhat secure as it would
> > > contain the whole memory image including security. For the NVRAM though
> > > it might uncover data stored there or even make the VM unbootable.
> > >
> > > I agree that the current state is not ideal as we basically force the
> > > user to specify all the necessary flags. I think we can safely avoid
> > > displaying the message in cases when it's not stored in the
> > > libvirt-internal path but for the internal path I'm not convinced that
> > > it would be a great idea to change the default.
> > 
> > This is the problem with trying to put this kind of policy into libvirt
> > though. It is targetting one use case, but has forgotten other valid
> > use cases. For example, consider if the NVRAM file or the managed save
> > image were stored in a filesystem that was NFS. The application wishes
> > to undefine the config on one host and define it on another host. Any
> > checks of this kind will always be wrong for some portion of use cases.
> 
> The mgmt app has the option to use either non-managed save or store the
> NVRAM in a non-default location for example ...

I remember that in the virDomainCreateFlags we have START_FORCE_BOOT
which is defined to discard any existing managed save file.

Should we either extend that to also discard the NVRAM file, or alternatively
add a START_RESET_NVRAM flag as a way to boot with clean BIOS ?

Regards,
Daniel
-- 
|: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org              -o-             http://virt-manager.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|




More information about the libvir-list mailing list