Re: [Qemu-devel] [PATCH v4 0/6] Efficient VM backup for qemu

[Dietmar Maurer]

> On Fri, Feb 22, 2013 at 2:07 PM, Paolo Bonzini <address@hidden> wrote:
> > Il 22/02/2013 14:02, Dietmar Maurer ha scritto:
> >>> But you can always sandbox using SELinux, if you care about that, or
> >>> use a Unix socket + SCM_CREDENTIALS.
> >>
> >> unix sockets works with qemu nbd code?
> >
> > Sure.  nbd+unix:///exportname?socket=path is the new URI syntax, I
> > honestly forgot the old one.  SCM_CREDENTIALS checks (qemu-nbd --pid
> > or something like that) is not supported, but patches would be very welcome.
> 
> Yes, this is better than my tcp suggestion.

If we use nbd, how can we pass additional information to the other side, for 
example
information about unallocated regions?