Ian Campbell writes ("[Xen-devel] Xen 4.2 TODO / Release Plan"):
> Plan for a 4.2 release:
> http://lists.xen.org/archives/html/xen-devel/2012-03/msg00793.html
...
> tools, blockers:
>       * libxl stable API -- we would like 4.2 to define a stable API
>         which downstream's can start to rely on not changing. Aspects of
>         this are:
>               * Safe fork vs. fd handling hooks. Involves API changes
>                 (Ian J, I think this was actually DONE a while back and
>                 I missed it)

This is indeed committed.

>               * libxl_wait_for_free_memory/libxl_wait_for_memory_target.
>                 Interface needs an overhaul, related to
>                 locking/serialization over domain create (deferred to
>                 4.3). IanJ to add note about this interface being
>                 substandard but otherwise defer to 4.3.

I have yet to write such a note.

>               * libxl_*_path. Majority made internal, only configdir and
>                 lockdir remain public (used by xl). Good enough?

Yes.  We should perhaps add a note saying that the lockdir path
function should not be used by out-of-tree callers.

>               * Interfaces which may need to be async:
>                       * libxl_domain_suspend. Probably need to move
>                         xc_domain_save into a separate process, as per
>                         <20366.40183.410388.447630@mariner.uk.xensource.com>. Likely need to do the same for xc_domain_restore too. (IanJ).

I am working on this.

>                       * libxl_domain_create_{new,restore} -- IanJ has
>                         patches as part of event series, (DONE).

Yes.

>                       * libxl_domain_core_dump. Can take a dummy ao_how
>                         and remain synchronous internally. (IanC, DONE)

Yes.

>                       * libxl_device_{disk,nic,vkb,add,pci}_add (and
>                         remove?). Roger Pau Monné fixes disk as part of
>                         hotplug script series and adds infrastructure
>                         which should make the others trivial. (Roger,
>                         WIP)

Right.

>                       * libxl_cdrom_insert. Should be easy once
>                         disk_{add,remove} done, IanJ to look at (or
>                         doing so?).

This isn't on my proximate todo list yet.

>                       * libxl_device_disk_local_{attach,detach}. Become
>                         internal as part of Stefano's domain 0 disk
>                         attach series (patches posted, another round
>                         required?)

I believe I am expecting a revised series from Stefano, yes.

>                       * libxl_fork -- IanJ's event series will remove
>                         all users of this. (DONE)

Yes.

>       * xl compatibility with xm:
>               * [BUG] cannot create an empty CD-ROM driver on HVM guest,
>                 reported by Fabio Fantoni in
>                 <4F9672DD.2080902@tiscali.it>

This needs my attention.

>               * does not automatically try to select a (set of) node(s)
>                 on which to create a VM and pin its vcpus there. (Dario
>                 Faggioli, patches posted)

This is still in progress somehow ?

>       * More formally deprecate xm/xend. Manpage patches already in
>         tree. Needs release noting and communication around -rc1 to
>         remind people to test xl.

Good.

>       * xl to refuse to run if xend is running, Roger Pau Monné (patch
>         posted, needs rebase)

Committed.

>       * Domain 0 block attach & general hotplug when using qdisk backend
>         (need to start qemu as necessary etc) (Stefano S, patches
>         posted, needs updates)

Is this not the same as the libxl_device_disk_local_{attach,detach}
series you mention above ?

>       * Improved Hotplug script support (Roger Pau Monné, patches
>         posted)

These are currently undergoing review/rework.

>       * Block script support -- follows on from hotplug script (Roger
>         Pau Monné)

Right.

>       * xs.h -> xenstore.h. Should do this for 4.2 rather than have
>         distros carry their own patches. (Ian C, patch posted)

I will be applying this today I hope.

> tools, nice to have:
>       * Initial xl support for Remus (memory checkpoint, blackholing)
>         (Shriram, was waiting on libxl side of qemu upstream
>         save/restore, now unblocked)

Yes.

>       * xl compatibility with xm:
>               * xl support for autospawning vncviewer (vncviewer=1 or
>                 otherwise) (Goncalo Gomes, new version of patch posted
>                 recently)

I think we are awaiting a reworked series from Goncalo.

>       * Directory usage in libxl (Bastian, as part of Debian packaging,
>         likely to defer to 4.3 unless there is some big problem with
>         packaging deviating from upstream)

I think this can wait.

Ian.