[libvirt] [sandbox PATCH 2/3] Add configuration object for disk support

[Cedric Bosdonnat]

Hi Daniel,

On Thu, 2015-06-11 at 14:47 +0100, Daniel P. Berrange wrote:
> On Wed, Jun 10, 2015 at 01:40:09PM +0200, Eren Yagdiran wrote:
> > Add the config gobject, functions to store and load the new configuration
> > fragments and test. This will allow creating sandboxes with attached
> > disk with a parameter formatted like file:hda=/source/file.qcow2,format=qcow2
> 
> > +/**
> > + * gvir_sandbox_config_add_disk_strv:
> > + * @config: (transfer none): the sandbox config
> > + * @disks: (transfer none)(array zero-terminated=1): the list of disks
> > + *
> > + * Parses @disks whose elements are in the format TYPE:TARGET=SOURCE,FORMAT=FORMAT
> > + * creating #GVirSandboxConfigMount instances for each element. For
> > + * example
> > + *
> > + * - file:hda=/var/lib/sandbox/demo/tmp.qcow2,format=qcow2
> > + */
> 
> One of the goal of the libvirt sandbox code is to insulate apps from
> needing to know hypervisor specific differences. The guest side disk
> device name is one such big difference. Many hypervisors, including
> kvm, will not even honour requested names - you just get whatever
> name the guest decides to give you. Essentially the only thing that
> libvirt guarantees is the disk ordering. ie if you configure two
> disks one with hda and one hdb, libvirt will ensure hda appears
> before hdb on the bus or controller.
> 
> So I don't think we should include the target device name in our
> configuration syntax here. We should just document that disks
> will be added to the guest in the same order that you supply
> them to virt-sandbox command line in. The actual device names
> will vary according to the hypevisor and guest os.

Right. But I think we then need to ask for the bus type then, so that we
know whether we'll have ide, scsi or whatever. Then we could have the
option like:

file:ide=/path/to/source,format=fmt

And of course document that the disks will be added in the same order.

Does it sound better for you?

--
Cedric

> > +gboolean gvir_sandbox_config_add_disk_strv(GVirSandboxConfig *config,
> > +                                           gchar **disks,
> > +                                           GError **error)
> > +{
> > +    gsize i = 0;
> > +    while (disks && disks[i]) {
> > +        if (!gvir_sandbox_config_add_disk_opts(config,
> > +                                               disks[i],
> > +                                               error))
> > +            return FALSE;
> > +        i++;
> > +    }
> > +    return TRUE;
> > +}
> 
> Regards,
> Daniel