ACRN Project Technical Community Meeting Minutes - 10/10

Wang, Hongbo

ACRN Project TCM - 10th October 2018
  1. ACRN project update
ACRN + Open Source version Android is working, will publish guide later.
  1. Cao, Minggui:  Interrupt Storm Mitigation
Download foil from ACRN Presentation->ACRN_TCM->WW41’18.
  1. All: Community open discussion.
Q: Does Intel hardware also has hardware limitation of interrupts? for e.g. if in case of level edge triggered the interrupts are generated until the level is changed.. in this case would Intel hardware limit interrupt?   A: Yes, for some device, it can reduce.
Q: Can this capability be a statically configured as part of VM DM configuration info?  A: Is a good suggestion, per VM interrupt rate setting by using command line. For different VM, setting different threshold.
Q:Once the device is passed through it means only that VM will handle that device ...then what is the need to make a hypercall and inject an interrupt ..back to UOS again.  A: No, the hypercall is not used to inject interrupt.
Q: how is interrupt storm affecting SOS? (2) why is interrupt injection enabled for SOS? may be we can turn it off after UOS is boot up? The concerpt of passthrough only applies to UOS.  A: Even device passed through to UOS, the interrupt sill needs go through hypervisor.
Q: Can post-interrupt solve the interrupt storm by bypassing the hypervisor?  A: for APL platform, it doesn’t support post-interrupt.  And VT-d device will go through hypervisor too.
One comment: One problem you have is that once you start throttling a particular interrupt you will not know when the storm has ended because your data is now skewed since many devices cannot inject a new interrupt until the previous interrupt has been serviced.   Throttling will need a timeout.
  1. Next meeting agenda proposal:
WW Topic Presenter Status
WW21 ACRN roadmap introduction Ren, Jack Done
WW22 Patch submission process
ACRN feature list introduction
Wang, Hongbo
Ren, Jack
WW23 Memory Management Chen, Jascon Done
WW24 Boot flow and fast boot Wu, Binbin Done
WW25 Memory Management Chen, Jason C Done
WW26 Audio virtualization Li, Jocelyn Done
WW27 Trusty Security on ACRN Zhu, Bing’s team Done
WW28 Clear Linux and use on ACRN Du, Alek Done
WW29 GVT-g for ACRN (a.k.a AcrnGT) Gong, Zhipeng Done
WW30 Device pass-through Zhai, Edwin Done
WW31 ACRN logical partition Ren, Jack/Xu, Anthony Done
WW32 ACRN interrupt management Chen, Jason Done
WW33 ACRN ACPI virtualization Edwin Zhai Done
WW34 ACRN S3/S5 management Fengwei Yin Done
WW35 ACRN P-state/C-state management Victor Sun Done
WW36 CPU Virtualization Jason Chen Done
WW37 Joint Design: VM Configuration Options Discussion Fengwei Yin Done
WW38 Joint Design: Remove dynamic memory allocation from ACRN memory management Li, Fei Done
WW39 USB virtualization Wang, Yu Done
WW41 Interrupt Storm Mitigation Cao, Minggui Today
  1. 2018 IoT solution world Congress
  1. Oct’18
  2. One talk and one demo accepted
  1. 2019 Embedded World Exhibition & Conference
  1. Feb. 26-28, 2019
  2. CFP deadline: Aug. 31, 2018
  3. Nuremberg, Germany
  1. Project URL:
  1. Portal:   
  2. Source code:   
  3. email: info@...g
  4. Technical Mailing list: acrn-dev@...g
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