Xen 4.4 development update: RC0 imminent

[George Dunlap <George.Dunlap@eu.citrix.com>]

This information will be mirrored on the Xen 4.4 Roadmap wiki page:
 http://wiki.xen.org/wiki/Xen_Roadmap/4.4

We're nearly to the completion of the code freeze, scheduled for
tomorrow.  After the code freeze, only bug fixes and features marked
as "blockers" will be considered.  At the moment, the only feature
considered a blocker is experimental PVH dom0 support.

In early RCs, most bug fixes will be accepted; but in later RCs, even
bug fixes may be rejected if they risk breaking more important
functionality than they fix.

I don't think at this point every bug fix needs a blessing from me;
committers, if there are fixes which are obviously low-risk, just go
ahead and check them in.

I was thinking that for some of our new features, it would be good to
have a blog post describing the feature and how to test it.  This
would both raise awareness of the feature, and hopefully get it more
testing before the release.  We could choose a couple to focus on for
each test day.

The code freeze will be complete tomorrow, but we will not be cutting
the first RC until PVH dom0 support gets in (hopefully in the next few
days).

= Timeline =

Here is our current timeline based on a 6-month release:

* Feature freeze: 18 October 2013
* Code freezing point: 18 November 2013 <== WE ARE HERE
* First RCs: 6 December 2013
* Release: 21 January 2014

Last updated: 5 December 2013

== Completed ==

* Event channel scalability (FIFO event channels)

* Non-udev scripts for driver domains (non-Linux driver domains)

* Multi-vector PCI MSI (Hypervisor side)

* Improved Spice support on libxl
 - Added Spice vdagent support
 - Added Spice clipboard sharing support

* PHV domU (experimental only)

* pvgrub2 checked into grub upstream (external)

* ARM64 guest

* Guest EFI booting (tianocore)

* kexec

* Testing: Xen on ARM

* Update to SeaBIOS 1.7.3.1

* Update to qemu 1.6

* SWIOTLB (in Linux 3.13)

* Disk: indirect descriptors (in 3.11)

== Resolved since last update ==

* xen_platform_pci=0 doesn't work with qemu-xen

== Open ==

* qemu-upstream not freeing pirq
 > http://www.gossamer-threads.com/lists/xen/devel/281498
 > http://marc.info/?l=xen-devel&m=137265766424502
 status: patches posted; latest patches need testing

* 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: Patches posted

* Supposed regression from a3513737 ("x86: allow guest to set/clear
 > MSI-X mask bit (try 2)"), as per
 > http://lists.xenproject.org/archives/html/xen-devel/2013-09/msg01589.html.

* qemu-traditional mis-parses host bus 8 as 0
 > http://bugs.xenproject.org/xen/bug/15

* xl does not support specifying virtual function for passthrough device
 > http://bugs.xenproject.org/xen/bug/22

* xl support for vnc and vnclisten options with PV guests
 > http://bugs.xenproject.org/xen/bug/25

* xl does not handle migrate interruption gracefully
  > If you start a localhost migrate, and press "Ctrl-C" in the middle,
  > you get two hung domains

* libxl / xl does not handle failure of remote qemu gracefully
  > Easiest way to reproduce:
  >  - set "vncunused=0" and do a local migrate
  >  - The "remote" qemu will fail because the vnc port is in use
  > The failure isn't the problem, but everything being stuck afterwards is

* xl needs to disallow PoD with PCI passthrough
  >see http://xen.1045712.n5.nabble.com/PATCH-VT-d-Dis-allow-PCI-device-assignment-if-PoD-is-enabled-td2547788.html

* HPET interrupt stack overflow (when using hpet_broadcast mode and MSI
capable HPETs)
  owner: andyh@citrix
  status: patches posted, undergoing review iteration.

* PCI hole resize support hvmloader/qemu-traditional/qemu-upstream
with PCI/GPU passthrough
  > http://lists.xen.org/archives/html/xen-devel/2013-05/msg02813.html
  > Where Stefano writes:
  > 2) for Xen 4.4 rework the two patches above and improve
  > i440fx_update_pci_mem_hole: resizing the pci_hole subregion is not
  > enough, it also needs to be able to resize the system memory region
  > (xen.ram) to make room for the bigger pci_hole

* qemu memory leak?
  > http://lists.xen.org/archives/html/xen-users/2013-03/msg00276.html

=== Big ticket items ===

* PVH dom0 (w/ Linux)
  owner: mukesh@oracle, george@citrix
  status (Linux): Acked, waiting for ABI to be nailed down
  status (Xen): v5 posted; considered a blocker

* libvirt/libxl integration (external)
 - owner: jfehlig@suse, dario@citrix
 - patches posted (should be released before 4.4)
  - migration
  - PCI pass-through
 - In progress
  - integration w/ libvirt's lock manager
  - improved concurrency

* libxl: Spice usbredirection support for upstream qemu
 > Includes usb2/3 support
 status: v2 acked
 prognosis: good