2020-10-01 Project Stratos Sync Meeting notes

Attendees

  • Mike
  • Arnd Bergman
  • Matt Spencer (Arm)
  • Alex
  • Masami 
  • Jesper (Redhat)
  • Srivatsa (Qualcomm)
  • Stefano (Xilinx)
  • Victor
  • Diana (NXP)
  • Ilias
  • Bill
  • Jean-Phillipe
  • Mathieu
  • Randy
  • Vincent
  • Tom
  • Bogdan (NXP)

Goals

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

Discussion items

  • Review Action items
  • Ilias Apalodimas Follow on  intoduction to XDP for VM acceleration.
    • XDP introduction. XDP as a building block
    • XDP for VMs acceleration
      • XDP work items
        • eBPF programs :  Ilias need real life usecases
        • XDP challenges and metadata usage : Jesper want to put HW offloads into metadata, remove the need to disable HW offload to use XDP,  intoducing HW features will be easier, no need to get patches into the kernel.
          • Arnd: guest eBPF and XDP, is there a way to move the filter one level up, this has been approached before, so far failed, security is an issue becasue bpf can access memory. 
          • Bill do you have any material, how does this out perform OVS for example. Ilias has a link David ? XDP vs OVS
            • OVS always allocates an SKB
        • H/W offloading features
      • virtio work items
        • virtio_net and XDP TX-queue problem
          • Packets get dropped if mis configured TX buffers, more of an issue with 100s queu per machine - think virtual cpus
        • virtio_net and XDP-multi-buffer support
          • can now support  jumbo frames, also TSO can try to redirect  big packet, results in performance drop when you expected boost. Alex does this resduce switchign overhead, yes it can pull as much as it has secduled time to do so.
        • Arndvirtio_net and scheduling the VM to consume packets (current bottleneck for PPS performance)

          • From host be smarter in schduling with guest
    • Alex : been looking at performance - virtio-audio/video - similar probelms of moving data between guests - vm exits
      • virtio-net - you mean the driver seen by the guest ?  the guest sees the same thing, the back ends can change Arnd : two areas, in guest to rerout in the same guest this is easy case. Host is KVM we have to vhost-next devices and this is more interesting. 
  • Masami Hiramatsu  Unknown User (victor.duan@linaro.org) Update on  AGL Demo plans
    • probelms with selected platform
    • Alex - Xen on Arm has issues based on ACPI, Mchiato bin not working yet on QEMU TCG
      • Staffano - great work this week
      • Masami dom0 on Xen with ACPI, many warnings, no network, For AGL we cant get things in place in time on Socionet platforms. Landing team will work on the devloper box, writing SoW for this now.
      • Steffano ,we can work arround this, linux EFI setting up gic mapping, efi not used with dom0, structures are missing aa result,  so just set them up elsewhere as a temporary fix. I can look later today
      • Alex - I will likly not use ACPI boot, so been using DT boot to allow graphics.
      • Steffano - ACPI is experimental, DT is rock solid
      • MS - DT parser looks broken, ST - this is not common, I can help fix this easily, more easily than with ACPI
      • MS - who has a Developer Box (SynQuacer)?  Alex has a headless one, never got graphics working.
      • Alex : lets take stock tomorrow (Friday)
      • Arnd - SBSA is about HW, Alex thought it was, turns out it did not make it.

Action items

  • Mike HolmesDo we have remote access Synquasers in the Lab : Update form Unknown User (milosz.wasilewski@linaro.org) there are no remote access boxes in the lab