Re: Xen 4.4 development update

[Jim Fehlig <jfehlig@suse.com>]

George Dunlap wrote:
> This information will be mirrored on the Xen 4.4 Roadmap wiki page:
>  http://wiki.xen.org/wiki/Xen_Roadmap/4.4
>
> Rather than try to predict precisely what will make it into what
> release (which was something of a disaster last release), I'm just
> going to borrow a term from the Agile world and call all uncompleted
> features the "Backlog".  I'll still track who is doing what, and when
> we get close, what state things seem to be in.
>
> As mentioned in another e-mail, we'll also be working on improving the
> regression tester.  Feel free to join us.
>
> And as always, if you are working on a feature / bug that you want
> tracked, please respond to this e-mail.
>
> = Timeline =
>
> As discussed elsewhere, I am proposing a 6-month release cycle.  Xen
> 4.3 was released on 9 July.  That would give us a release on 9 January
> 2014.  This is fairly close after the Christmas season, so I propose
> to make the estimated release date later, on 21 January, giving a few
> extra weeks for the holiday season:
>
> * Feature freeze: 18 October 2013
> * Code freezing point: 8 November 2013
> * First RC: 26 November 2013
> * Release: 21 January 2014
>
> Feedback on the estimated dates  is welcome.
>
> Last updated: 8 August 2013
>
> == Completed ==
>
> [none]
>
> == Open ==
>
> * xend still in tree
>
> * qemu-upstream not freeing pirq
>  > http://www.gossamer-threads.com/lists/xen/devel/281498
>  status: patches posted
>
> * __update_vcpu_system_time if system_time comes out negative
>
> * xl pci-detach broken for pv guests?
>   > http://bugs.xenproject.org/xen/bug/12
>   > kernel doesn't know about moving into states 7 and 8
>   status: External
>
> * Race in PV shutdown between tool detection and shutdown watch
>  > http://www.gossamer-threads.com/lists/xen/devel/282467
>  > Nothing to do with ACPI
>  status: Probably a bug in Linux xen drivers
>
> == Backlog ==
>
> === Testing coverage ===
>
> * Network driver domains
>  @George
>
> * new libxl w/ previous versions of xl
>  @IanJ
>
> * Host S3 suspend
>  @bguthro
>
> * Default [example] XSM policy
>  @Stefano to ask Daniel D
>
> * Xen on ARM
>  # hardware
>   @ianc
>    emulator: @stefano to think about it
>
> * Storage driver domains
>  @roger
>
> * HVM pci passthrough
>  @anthony
>
> * Nested virt?
>  @intel (chased by George)
>
> * Fix SRIOV test (chase intel)
>  @ianj
>
> * Fix bisector to e-mail blame-worthy parties
>  @ianj
>
> * Fix xl shutdown
>   @ianj
>
> * stub domains
>   @athony
>
> === Big ticket items ===
>
> * NUMA Memory migration
>   owner: dario@citrix
>   status: in progress
>
> * Event channel scalability
>   owner: david@citrix
>   status: RFC v5 submitted
>   Increase limit on event channels (currently 1024 for 32-bit guests,
>   4096 for 64-bit guests)
>
> * PVH mode (w/ Linux)
>   owner: mukesh@oracle
>   status (Linux): 3rd draft patches posted.
>   status (Xen): v10 posted
>
> * ARM stuff: ??
>
> * Meta: PVIO NUMA improvements
>  - NUMA affinity for vcpus
>     owner: Dario
>  - PV guest NUMA interface
>     owner: Elena
>  - Sensible dom0 NUMA layout
>  - Toolstack pinning backend thread / virq to appropraite d0 vcpu
>
> * qemu-upstream stubdom, Linux
>    owner: anthony@citrix
>    status: in progress
>    qemu-upstream needs a more fully-featured libc than exists in
>    mini-os.  Either work on a minimalist linux-based stubdom with
>    glibc, or port one of the BSD libcs to minios.
>
> * qemu-upstream stubdom, BSD libc
>   owner: ianj@citrix
>   

There is no mention of updating to the latest upstream qemu.  Wasn't
there talk of updating to the latest qemu release at the beginning of a
Xen development cycle?

> * Network performance improvements
>   owner: wei@citrix
>
> * Disk performance improvements
>
> * Xen EFI feature: Xen can boot from grub.efi
>  owner: Daniel Kiper
>  status: Just begun
>  prognosis: Fair
>
> * libvirt/libxl integration (external)
>  > need a status update
>  - owner: jfehlig@suse, dario@citrix
>   

The main items missing in the libvirt libxl driver wrt the legacy Xen
driver are migration and PCI passthrough.  But patches for both of these
features have been posted to the libvirt dev list

https://www.redhat.com/archives/libvir-list/2013-September/msg00667.html
https://www.redhat.com/archives/libvir-list/2013-September/msg00660.html

libvirt is on a monthly release cycle, so there will certainly be a
release containing these patches before Xen 4.4.

There are also patches in the works to add functionality that was
generally not possible in the legacy Xen driver, e.g. integration with
libvirt's lock manager, providing protection of disk resources.  I'm
also working on patches to improve concurrency in the driver.  Slowly,
with each libvirt release, the libxl driver is improving.

Regards,
Jim