Re: [Qemu-devel] Re: Storing command line options in images

Jorge Lucángeli Obes
2007-08-14T19:02:35Z

On 8/14/07, Laurent Vivier <Laurent.Vivier-6ktuUTfB/bM@public.gmane.org> wrote:
> Markus Hitter wrote:
> >
> > Am 13.08.2007 um 11:19 schrieb Laurent Vivier:
> >
> >> We can modify qemu to test if the argument is a directory, if yes, it
> >> reads args
> >> from file args in this directory and for security the disk image must
> >> be in the
> >> same directory.
> >>
> >> for instance, we have:
> >>
> >> ./pc1/
> >> ./pc1/args
> >> ./pc1/my_disk
> >>
> >> and in ./pc1/args, we have "-hda my_disk"
> >
> > ... and "-hdb ../pc2/my_other_disk"
>
> If we want to preserve security we should forbid this, but you can make a soft link:
>
> ln -s shared_disks/my_disk1 pc1/my_shared_disk
> ln -s shared_disks/my_disk1 pc2/my_shared_disk
>
> and have pc1/args and pc2/args = "-hda my_disk -hdb my_shared_disk"
> to have:
>
> qemu -hda pc1/my_disk -hdb pc1/my_shared_disk
>
> qemu -hda pc2/my_disk and -hdb pc2/my_shared_disk
>
> > The directory idea sounds good. Especially for me, as I'm obviously the
> > only one running one disk image in different virtual machines.
> >
> > Plus, it'd work for physical partitions / disks: Simply have a directory
> > with an "args" file only.
> >
> >
> > my $ 0.01
> > Markus

Quoting Thiemo, this '@' thing was "a feature which is now implemented
in the GNU toolchain". That's why I tried it. Now I would like to know
what he did to get it working. It would certainly be an useful
feature, even if it does not exactly suit our purposes.

I still think that the executable-image approach could work nicely.
However, the point in favour of a configuration directory when using
physical partitions or disks is good. Nonetheless, a physical
partition is much less "volatile" than an disk image, so the
disadvantage of keeping a shell script is small in that case.

Cheers,
Jorge