[libvirt] [PATCH] qemu: Always enable the virtio balloon driver

Daniel P. Berrange berrange at redhat.com
Tue Jan 5 10:00:29 UTC 2010

On Tue, Jan 05, 2010 at 09:43:32AM +0200, Dor Laor wrote:
> On 01/04/2010 07:13 PM, Adam Litke wrote:
> >The behavior for the qemu balloon device has changed.  Formerly, a virtio
> >balloon device was provided by default.  Now, '-balloon virtio' must be
> >specified on the command line to enable it.  This patch causes libvirt to 
> >add
> >'-balloon virtio' to the command line whenever the -balloon option is
> >available.
> Why add it automatically? I rather have the user state explicitly that a 
> balloon is required. If the balloon is not used, we're just wasting a 
> pci slot and enlarge the hypervisor signature.
> I'm in favor of using the balloon driver, but there are occasions it 
> won't be required or we won't have a guest driver for it.

Not having the balloon driver present is a regression from earlier 
libvirt behaviour, and likewise requiring it to be explicitly added
to a guest will cause an immediate regression for all apps using

|: Red Hat, Engineering, London   -o-   http://people.redhat.com/berrange/ :|
|: http://libvirt.org  -o-  http://virt-manager.org  -o-  http://ovirt.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505  -o-  F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|

More information about the libvir-list mailing list