Re: Xen 4.3 development update, and stock-taking

["Roger Pau Monné" <roger.pau@citrix.com>]

On 16/01/13 18:55, George Dunlap wrote:
> Below is a summary of the projects / features being worked on for the
> 4.3 time frame.  The tentative feature freeze is scheduled for 25 March,
> which is just over 2 months away.  With that in mind, I think it's time
> to take stock of the development, so we know whether to ask for more
> help or divert resources.
> 
> To that end, I've added a line called "prognosis", indicating the
> likelihood of completion in the 4.3 timeframe.  For items involving code
> hosted on the Xen.org site (including qemu-xen), that means a likelihood
> of having the feature code-complete and mostly working by the feature
> freeze.  (It's OK if there are still bugs to be worked out.)  For items
> in Linux, I think it would mean having items on track to make it into
> the kernel released just after the scheduled 4.3 time frame.  Not sure
> what that means for libvirt. :-)
> 
> I've given ratings to projects that I thought I had some insight on, but
> I would appreciate if everyone could review these and let me know if
> they're not accurate.
> 
> I'd particularly appreciate it if the people listed below could give
> prognoses on the project listed.
> 
> Meanings of prognoses:
> - Excellent: It would be very unlikely for this not to be finished in time.
> - Good: Everything is on track, and is likely to make it.
> - Fair: A pretty good chance of making it, but not as certain
> - Poor: Likely not to make it unless intervention is made
> - Not for 4.3: self-explanatory
> 
> Mukesh Rathor: PVH
> 
> Wei: Event channel scalability
> 
> Daniel de Graaf: IS_PRIV->XSM
> 
> Roger Pau Monne: Persistent blk grants, openvswitch integration, backend
> scripts
> 
> Konrad Wilk: Persistent net grants, multi-page network, multi-page blk
> 
> Jim Fehlig: libvirt migration support
> 
> Matthew Fioravante: vTPM
> 
> Stefano Panella: PV Audio
> 
> Igor Kozhukov: IllumOS support
> 
> Once we know what items are "at risk", we can list them and decide what
> to do about it.
> 
> This information will be mirrored on the Xen 4.3 Roadmap wiki page:
>  http://wiki.xen.org/wiki/Xen_Roadmap/4.3
> 
> = Timeline =
> 
> We are planning on a 9-month release cycle.  Based on that, below are
> our estimated dates:
> * Feature Freeze: 25 March 2013
> * First RC: 6 May 2013
> * Release: 17 June 2013
> 
> The RCs and release will of course depend on stability and bugs, and
> will therefore be fairly unpredictable.  The feature freeze may be
> slipped for especially important features which are near completion.
> 
> = Feature tracking =
> 
> Below is a list of features we're tracking for this release. Please
> respond to this mail with any updates to the status.
> 
> There are a number of items whose owners are marked as "?".  If you
> are working on this, or know who is working on it, please respond and
> let me know.  Alternately, if you would *like* to work on it, please
> let me know as well.
> 
> And if there is something you're working on you'd like tracked, please
> respond, and I will add it to the list.
> 
> NB: Several of the items on this list are from external projects:
> linux, qemu, and libvirt.  These are not part of the Xen tree, but are
> directly related to our users' experience (e.g., work in Linux or
> qemu) or to integration with other important projects (e.g., libvirt
> bindings).  Since all of these are part of the Xen community work, and
> comes from the same pool of labor, it makes sense to track the
> progress here, even though they won't explicitly be released as part
> of 4.3.
> 
> Meanings of prognoses:
> - Excellent: It would be very unlikely for this not to be finished in time.
> - Good: Everything is on track, and is likely to make it.
> - Fair: A pretty good chance of making it, but not as certain
> - Poor: Likely not to make it unless intervention is made
> 
> == Completed ==
> 
> * Serial console improvements
>   -EHCI debug port
> 
> * Default to QEMU upstream (partial)
>  - pci pass-thru (external)
>  - enable dirtybit tracking during migration (external)
>  - xl cd-{insert,eject} (external)
> 
> * CPUID-based idle (don't rely on ACPI info f/ dom0)
> 
> == Bugs ==
> 
> * xl, compat mode, and older kernels
>   owner: ?
>   Many older 32-bit PV kernels that can run on a 64-bit hypervisor with
>   xend do not work when started with xl.  The following work-around seems to
>   work:
>     xl create -p lightning.cfg
>     xenstore-write /local/domain/$(xl domid
> lightning)/device/vbd/51713/protocol x86_32-abi
>     xl unpause lightning
>   This node is normally written by the guest kernel, but for older kernels
>   seems not to be.  xend must have a work-around; port this work-around
> to xl.
> 
> == Not yet complete ==
> 
> * PVH mode (w/ Linux)
>   owner: mukesh@oracle
>   status (Linux): 3rd draft patches posted. 
>   status (Xen): RFC submitted
>   prognosis: Good
> 
> * Event channel scalability
>   owner: wei@citrix
>   status: RFC submitted
>   prognosis: Good
>   Increase limit on event channels (currently 1024 for 32-bit guests,
>   4096 for 64-bit guests)
> 
> * ARM v7 server port
>   owner: ijc@citrix
>   prognosis: Excellent
>   status: Core hypervisor and Linux patches accepted.  Tools patches
> submitted.
> 
> * ARM v8 server port (tech preview)
>   owner: ijc@citrix
>   status: ?
>   prognosis: Tech preview only
> 
> * NUMA scheduler affinity
>   critical
>   owner: dario@citrix
>   status: Patches posted
>   prognosis: Excellent
> 
> * NUMA Memory migration
>   owner: dario@citrix
>   status: in progress
>   prognosis: Fair
> 
> * blktap3
>   owner: thanos@citrix
>   status: RFCs posted
>   prognosis: Not for 4.3
> 
> * Default to QEMU upstream
>  > Add "intel-hda" to xmexample file, since it works with 64-bit Win7/8
>  - qemu-based stubdom (Linux or BSD libc)
>    owner: anthony@citrix
>    status: in progress
>    prognosis: ?
>    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.
> 
> * Persistent grants for blk (external)
>   owner: roger.pau@citrix
>   status: Initial implementation posted
>   prognosis: ?

Done, Linux implementation scheduled for 3.8, and Qemu side is also done
and being upstreamed right now.

> 
> * Persistent grants for net
>   owner: annie.li@citrix
>   status: Initial implementation posted
>   prognosis: ?
> 
> * Multi-page blk rings (external)
>  - blkback in kernel (konrad@oracle, ?@intel)
>  - qemu blkback
>   status: Not started.
>   prognosis: UNKNOWN

I will be taking on this project, following Intel, FreeBSD and Konrad
suggestions. Since I'm just starting now, I will mark it as "Fair".

> 
> * Multi-page net protocol (external)
>   owner: ijc@citrix or annie.li@oracle
>   status: Initial patches posted (by Wei Liu)
>   expand the network ring protocol to allow multiple pages for
>   increased throughput
> 
> * Scalability: 16TiB of RAM
>   owner: jan@suse
>   status: Not started
> 
> * vTPM updates
>   owner: Matthew Fioravante @ Johns Hopkins
>   prognosis: Good
>   status: some patches submitted, more in progress
>   - Allow all vTPM components to run in stub domains for increased security
>   - Update vtpm to 0.7.1 from 0.5.x
> 
> * Guest EFI booting
>  - status: tianocore in-tree, some build problems.
>    prognosis: Poor.
>    Needs new owner.
> 
> * libvirt/libxl integration (external)
>  - Update libvirt to 4.2
>    status: Patch accepted
>  - Migration
>    owner: cyliu@suse (?)
>    status: first draft implemented, not yet submitted
>    prognosis: ?
>  - Itemize other things that need work
>    To begin with, we need someone to go and make some lists:
>    - Features available in libvirt/KVM not available in libvirt/libxl
>      See http://libvirt.org/hvsupport.html
>    - Features available in xl/Xen but not available in libvirt/Xen
> 
> * Allow XSM to override IS_PRIV checks in the hypervisor
>   owner: Daniel De Graaf
>   status: patches against 4.3-unstable posted, awaiting approval
>   prognosis: Good
>   This makes it possible to allow some user domains limited access to
>   dom0-only hypercalls. This could be used to allow a user-created
>   toolstack domain to administer its own set of VMs instead of relying
>   on dom0's toolstack.
> 
> * V4V: Inter-domain communication
>   owner (Xen): jean.guyader@citrix.com <mailto:jean.guyader@citrix.com>
>   status (Xen): patches submitted
>   prognosis: ?
>   owner (Linux driver):  stefano.panella@citrix
>   status (Linux driver): in progress
> 
> * Wait queues for mm
>   owner: ?
>   status: Draft posted Feb 2012; more work to do.
>   prognosis: Poor
> 
> * xl PVUSB pass-through for both PV and HVM guests
>   owner: George
>   status: ?
>   prognosis: Fair
>   xm/xend supports PVUSB pass-through to guests with PVUSB drivers (both
> PV and HVM guests).
>   - port the xm/xend functionality to xl.
>   - this PVUSB feature does not require support or emulation from Qemu.
>   - upstream the Linux frontend/backend drivers. Current
> work-in-progress versions are in Konrad's git tree.
>   - James Harper's GPLPV drivers for Windows include PVUSB frontend drivers.
> 
> * xl USB pass-through for HVM guests using Qemu USB emulation
>   owner: George
>   status: Config file pass-through submitted.
>   prognosis: Good
>   xm/xend with qemu-traditional supports USB passthrough to HVM guests
> using the Qemu emulated USB controller.
>   The HVM guest does not need any special drivers for this feature.
>   So basicly the qemu cmdline needs to have:
>      -usb -usbdevice host:xxxx:yyyy
>   - port the xm/xend functionality to xl.
>   - make sure USB passthrough with xl works with both qemu-traditional
> and qemu-upstream.
> 
> * xl QXL Spice support
>   owner: Zhou Peng
>   prognosis: Fair
>   status: Patches against 4.3-unstable posted, awaiting approval
> 
> * Remove hardcoded mobprobe's in xencommons
>   owner: ?
>   status: ?
>   prognosis: Poor.
> 
> * openvswitch toostack integration
>   owner: roger@citrix
>   prognosis: ?
>   status: Sample script posted by Bastian ("[RFC] openvswitch support
> script")

I have no experience with Open vSwitch, so if some with more experience
wants to take on this I would appreciate it. It should just be a matter
of adding a hotplug script.

> 
> * Rationalized backend scripts (incl. driver domains)
>   owner: roger@citrix
>   status: patches submitted
>   prognosis: Good

The first part of this effort, that includes a new hotplug interface for
libxl has been submitted for review. The protocol between the control
and the driver domains still needs to be designed/revised based on Ian
Jackson proposal.

> * Xen EFI boot
>  - Signature checking for dom0 kernel / initrd?
>  status: No owner.
>  prognosis: Probably not for 4.4
> 
> * Serial console improvements
>   owner: ?
>   status: Stalled (see below)
>   prognosis: Probably not for 4.4.
>   -xHCI debug port (Needs hardware)
>   -Firewire (needs hardware)
> 
> * Make storage migration possible
>   owner: ?
>   status: none
>   prognosis: Probably delay until 4.4
>   There needs to be a way, either via command-line or via some hooks,
>   that someone can build a "storage migration" feature on top of libxl
>   or xl.
> 
> * Full-VM snapshotting
>   owner: ?
>   status: none
>   prognosis: Probably delay until 4.4
>   Have a way of coordinating the taking and restoring of VM memory and
>   disk snapshots.  This would involve some investigation into the best
>   way to accomplish this.
> 
> * VM Cloning
>   owner: ?
>   status: none
>   prognosis: Probably need 4.4
>   Again, a way of coordinating the memory and disk aspects.  Research
>   into the best way to do this would probably go along with the
>   snapshotting feature.
> 
> * xl vm-{export,import}
>   owner: ?
>   status: none
>   prognosis: Prob put off until 4.4 (or GSoC project)
>   Allow xl to import and export VMs to other formats; particularly
>   ovf, perhaps the XenServer format, or more.
>  
> * Memory: Replace PoD with paging mechanism
>   owner: george@citrix
>   status: none
>   prognosis: Prob put off until 4.4
> 
> * PV audio (audio for stubdom qemu)
>   owner: stefano.panella@citrix
>   status: ?
>   prognosis: ?
> 
> * IllumOS support
>   owner: Igor Kozhukov
>   status: In progress
>   prognosis: ?
>