2020-09-17 Project Stratos Sync Meeting notes

Owned by Mike Holmes
Last updated: Dec 17, 2021
5 min read

Attendees

  • Bill
  • Ilias
  • Mathieu
  • Alex
  • Masami
  • Mike
  • Joakim
  • Bogdan
  • Diana
  • Mark
  • Souvik
  • Vincent
  • Jean-Phillip
  • Steffano
  • Anmar
  • Ruchika
  • Francois
  • Don
  • Azzedine
  • Satyaki
  • Bill Fletcher
  • Randy
  • Tom
  • John Niven

Goals

  • Get a view of the  engineering support available to work on Stratos

Discussion items

  • Review Action items
  • Vincent Guittot Interconnect resource bandwidth in a VM
    • discussed with several people( souvik, Georgi), we want to rely on SCMI for thing like clock, regulator, reset ...
    • bandwidth / bus scaling is not available in virtio spec nor SCMI spec
    • do have perf domain in scmi spec - goal to use SCMI perf domain as interconnect bus scaling provider - need consumer on backend and aggregate requests from various VM
    • bus scaling is used for the display
    • Souvick - what is the framwork today, Vincent: it is interconnect framework - absolute bandwidth
    • Alex : consumer is most secure/where does the consumer live?
    • Vincent: system design could be several levels, need to aggregate all VMs and talk to power co processor or SCMI server.
    • Alex: will it always be secure?
    • Vincent: could live in a secondary VM which may have delegated access to non-secure resources (but two channels prob one secure and a regular channel)
  • Ilias Apalodimas Brief intoduction to XDP for VM acceleration. Basic concept and gains are mentioned in the following presentations
    • https://netdevconf.info/0x14/pub/slides/24/netdev-0x14-XDP-and-the-cloud.pdf
    • https://people.kernel.org/dsahern/xdp-vs-ovs  <<-
    • XDP - is express data path - been discussing for a long time. David on netdev made a good presentation that has been a catalyst. XDP allows bpf to decide if packets can be dropped, no need for allocations - IDEA to expand this to VMs, generating one escapee less - initial tests in intel 1mpp raises to 4mpp
    • Haven't done this before due to need for iptables - now XDP allows chaining of programs.  1. drop packets no allocation, high end socionext, Intel, marvell only drivers supprting XDP currently.  Work to do this failry well defined, some things missing in XDP - have to dissable hw checksum  for example.
    • on line talk was much better than the docs - will add the link when it becomes available
    • Azzedine : yes, more information would be welcome. Illia - have socionext box might be able to generate a PoC to measure performance
    • Alex :  ??  Illias cant push bpf from guest to host.,   the drop via XDP is  line rate vs n pps via  ??
    • Steffano : what is needed what is special Illias: its not special,  Stefano - difficulty is identifying the flow that is needed 
    • Francois : OVS tradtionally, dpdk accelerated this, but goal is OVS with XDP
  • Masami Hiramatsu (Deactivated) Describe Socionext AGL Demo plans
    • October AGL has virtual event - OpenSynergy / Panasonic demo - with VirtIO sound (question)
    • 96Board - SynQuacer - Socionext landing team to work on this - show AGL work on type1 and type2 hypervisor - also plan to add a member engineer to this.
  • Tom Gall LCG Update : Secure Media with Virtualized Android
    • MMWG & LCG straos update - PoR take a run at secure media, archetect with SWG, MMWG
    • Demo is a little in the future, could do this today, but in virt / secure enclave it can be done differently. 
  • Alex Bennée New Work 

    • Implement Optimized VirtIO interfaces (STR-9)

      • STR-5 - VirtIO RPMB
        • Azzedine : is it working ?  Alex blockers spec differs from what the driver does, been fixing the kernel, a few edges to clean up. This may lead into minimal memory profile, not many examples, this may be a good candidate for example
      • STR-8 - Prototype a minimal memory profile virtio backed with front end changes
        • STR-6 - VirtIO-MMU support for inter-guest memory protection
        • STR-15 - A linux host API for proving a limited sharing of a range of address space between two KVM guests
        • Stefano : I have feedback - will do off line  - quick thoughts
          • This should work on any Hvz, be good to have a design doc for a type-1 (Xen)  imagine soemthing like virtio-net - confomrs to  standards, arch understood. Here there is ahigh chance this will not end up like that. the virtio memory mapping becaend will be in Xen becasue the meory is handled by Xen.  This is challenging, this is a new exciting thing. Design needs to be cross Hyz -  just page long. 
          • Alex : Xen has grant tables already doent it ?  S: if we use table model - then yes we can do this, but virtio spec says you should not use references on the rings. Also if virtiommu in Xen will that be ok ? versiosning problem. S: waterfall does not work, just want to sketch issues
          • Alex will sync with Arnd B and stimulate discussion on the lists 
      • STR-13 - A demonstration of the portability of Virtio FE's between KVM and Xen systems

      Remaining effort for 4 planned epics: 6.2 engineer months

  • Mike Holmes LInaro connect  Virtualization and Stratos fire side chat
  • Mike Holmes Unknown User (victor.duan@linaro.org) François Ozog (Deactivated) Notes from AGL discussion on virtio devices needed
    • Companies:   at least WD, Panasonic, OpenSynergy, Tuxera, Linaro (Mike, Victor, Francois) - 15 participants
    • Demo discussion
      • Opensynergy demo :  virtio devices - blk, net, input, gpu(2d) - they will not use sound or video. AGL HH 8.x → commitment that new version is coming out and Halibut is old, perhaps we need to target the new version ?
      • Linaro demo :  requested information on the virtio interfaces and VM s to be used. Ideally, we want to show both KVM and Xen boot on the same setup.
    • Virtio Backend  standardization - AGL asking for participants
    • Virtio interfaces under discussion for 1.2 and 1.2+
      • SCMI - mentioned that Linaro working in the area. Use cases, Automotive reboot some parts of the system, also talk of the sensors - gps data
      • video
      • i2c - no spec
      • wayland - no spec
        • Alex - is this the chromeos : Bill it is multi distro - Can ask Gunter perhaps Tom will try to dig this up
        • Chrome OS - each application has a wayland connection, host owns the root Bill - used to be vm owned a plane. 
    • François Ozog (Deactivated) -  Infotainment missing  of interest to Linaro teams, and a request to complete the list
      • camera - virtio-camera
      • Machine learning - virtio-nn
      • storage - virtio-usb
      • Wall Clock - nothing
      • FF: talked about radio - tuner, virtio io should limit that - a virtio-tuner, no need for virtio-radio as such.
    • Alex do we need to make cards: FF generate doc perhaps, list devices per  use case
    • Bill : any context on AGL - security, safety cert, or just isolation
      • FF: Genive white paper, this is in Jira
    • Anmar are we invloved in the 1.2 spec Alex is reviewing the virtio spec patches today!  it is a slow process, engineers have day jobs
    • Souvik - work log, is that  MIke to find AGL links.
    • Tom  : as we close down the cycle in LCG, CTS and VTS is working on NXP HW with cuttlefish - we have an enviroment to pick up startos patches to see what affect there is on performance, Azzedine that is grea, is there anything published, Tom we have it but shy sharing the numbers but the benchmarks can be shared. Can make the data comparative.  Google are aware - Alistair
  • Action items