Re: [PATCH] migration: Add canary to VMSTATE_END_OF_LIST

[Dr. David Alan Gilbert]

* Peter Maydell (peter.maydell@linaro.org) wrote:
> On Wed, 12 Jan 2022 at 10:24, Dr. David Alan Gilbert (git)
> <dgilbert@redhat.com> wrote:
> >
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> >
> > We fairly regularly forget VMSTATE_END_OF_LIST markers off descriptions;
> > given that the current check is only for ->name being NULL, sometimes
> > we get unlucky and the code apparently works and no one spots the error.
> >
> > Explicitly add a flag, VMS_END that should be set, and assert it is
> > set during the traversal.
> 
> Does 'make check' definitely do the traversal for all vmstate
> structs, or do we need to add a "sanity check them all on startup"
> bit of test code ?

Oh I doubt it does; some vmsd's are conditional on guest state, many are
only on particular machine types.

I think the closest we have to being able to walk the tree, is
--dump-vmstate - although you need to call that for each machine type.
(I forgot to add the canary check in the dump-vmstate code, I'll fix
that).

Dave

> thanks
> -- PMM
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK