TCT Meeting/January 2014 Minutes

From Xen


  • Andres Lagar-Cavilla
  • Andrew Cooper
  • Anthony Liguori
  • Daniel Kiper
  • Don Dugger
  • Ian Campbell
  • Jan Beuluch
  • Jun Nakajima
  • Kelly Zytaruk
  • Konrad Rzeszutek Wilk
  • Olaf Herring
  • Sheery Hurwitz
  • Suravee Suthikulpanit

Review ACTION Items

  • Konrad to arrange for some PVH instructions for test days. Blog post in progress.

Current Technical Challenges

  • Konrad: Reports PCI passthrough Regresssion in 4.4 qemu-xen for PCI passthrough.
    • 4.3 qemu-xen did work.
    • Anthony didn't have hardware, has been directed to where to find some.
    • Konrad is seeing it with a normal NIC (Intel 82576), passing through the PF and not the VF.
    • Don: Intel have tested passthrough with 4.4 and qemu-xen and it works for them.
    • Andrew: Could also be the SeaBIOS update
    • Konrad: Tested version from June/July.

    • Pictogram voting comment 15px.png Action Konrad: Konrad to contact Don to see if we can resolve
  • Andrew Cooper: 4.4 has been through a XenRT run with XenServer. But didn't show PCI passthrough because that isn't tested.
    • Seeing similar Windows issues to those seen with osstest
    • Some PV guests didn't reboot, still to diagnose
  • Sherry: Is the community asking for testing of various PCI devices
    • Ian: Yes.
  • Suravee: Regression on 4.3/4.4 for AMD IOMMU. Fix was committed yesterday, should probably be back ported.
  • Boris: What are the plans for 4.3.2?
    • Jan: was planning 4.2.4. Waiting on Ian Jackson for tools backports.
    • For 4.3.2, at least a month before the regular schedule would call for a new 4.3.x release. There don't seem to be many big changes.
    • May align 4.3.2 and 4.2.4 releases at end of Jan early Feb.

Coordinaton of future work

  • Konrad is continuing to work with testing PCI passthrough.
    • Concentrating on reports for now, once there is some firm idea of what needs to be done will start looking at patches (but rather tied up with PVH at the moment)
    • Sherry: Kelly (on the call) can answer questions about graphics passthrough to radeon cards etc.
    • Kelly: Is working with 4.2 and has identified some issues with GFX passthrough, with qemu and seabios in particular. Has some fixes but needs to rebase to 4.4. Issues are mainly with passthrough of primary.
    • Konrad: Having issues with secondary passthrough, issues with rombios fixup.
    • ROMBIOS needs patches from David Techer in some circumstances
    • Kelly: Hardware has two BARs, which are not remapped correctly. video bios does not go through pci config space to get the bars so the accesses are not trapped and qemu doesn't update the mapping.
    • Andy Cooper: One of David Tetcher's patches looks relevant.
    • Kelly: Problems with multiple graphics cards in the host. Takes BIOS from 0xc000 (i.e. out of memory instead of out of ROM). Which means the boot card's BIOS gets used, which fails with passing through a non-boot graphics card. Fixed by reading the image from the rombar.

    • Pictogram voting comment 15px.png Action Kelly: Kelly to mail Konrad and/or xen-devel with the current set of issues.
    • Focus should be on qemu-xen+seabios and not qemu-trad+rombios
  • Andrew Cooper: There is an issue with high MMIO regions, PV pvops kernels cannot handle these well. Which breaks passthrough of these cards. Affects dom0
    • Konrad: Known and in progress.
  • Release: Looking like mid Feb.
  • Konrad: We have the option of sponsoring an internship via the GNOME Outreach Program for Women.
    • Soliciting ideas for interesting projects on Xen or Linux. Wants people to think about it
      • Andres: Recent Xen paging discussions.
    • Will be a formal request as the process ramps up.
  • Sherry: Next Xen test day.
    • Ian: I should know but I don't. Plan was maybe to have one alongside each RC? Should know but doesn't