ACRN Project Technical Community Meeting Miutes - 9/19/2018

Wang, Hongbo

ACRN Project TCM - 19th September 2018
  1. ACRN project update
1.1 ACRN community survey: need to provide more technical docs, user case, invite joint design.
1.2 Open Source version Android (a.k.a “Celadon”) open sourced.
1.3 Slimboot Loader project open sourced.
  1. Li, Fei:  Try to remove dynamic memory allocation from ACRN memory management
Download foil from ACRN Presentation->ACRN_TCM->WW38’18.
  1. All: Community open discussion.
Q: MISRA C will apply to ACRN, SOS, DM? A: As first step, only ACRN hypervisor itself will  go through MISRA C compliance. It does not include the SOS yet. We may switch to VxWorks which is safety. In that case, we don’t to apply MISRA C to it. Otherwise, it requires more efforts. Then we can move to next level, like DM if it required.
Q: What is the safety integrity level ACRN targets at? Is absence of dynamic memory allocation highly recommended for such levels?
A: Static resource allocation is highly recommended for SIL 3/ASIL B and above, in addition to being a required directive in MISRA C. To make it possible for ACRN to be certified for a high safety integrity level, we consider static resource allocation mandatory, at least for releases to our customers who want to integrate ACRN in safety-critical use cases.
Q: There’re two option proposals for the implementation. Can an EPT find an address by VM id index and GPA?  A: If we want to support free page table when runtime, another input parameter ‘page table level’ may needs. If not, VM id index is enough.
Q: What’s performance impact on using large EPT page tables ? A: 2~4% performance gain in server platform. For RT VM, maybe use small page table. That depends the special runtime situation on the special hardware platform.
Q: If the performance gain to use large EPT page tables is not critical,  can we just simple the code not to merger the small dis-contiguous to a large EPT page table when runtime ? A: Let’s see. As the first step, we should remove the dynamic allocation to meet the FuSA’s requires. If  it’s performance critical then we would do it later. It would much easier to merge it after we implement the static memory allocation since it’s a contiguous array.
Q: How to configure the system memory if using static memory allocation ? A: ACRN is for IoT embedded system. The SW should be shipped along with HW. The configuration is fixed. And it will not apply to platform with the different hardware. For developer, you should use Kconfig to configure it by yourself.
Q: Will ACRN keep the error code in static memory allocation case  or keep dynamic allocation for open source release ? A: No, we could ASSERT the system  since it would never fail. As for whether needs to keep the dynamic allocation for open source release,  it’s an open to be closed.

  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 Today
WW39 IPU Sharing Bandi, Kushal Plan
WW40 USB virtualization Yu Wang Plan
WW41 ACRN VT-d Binbin Wu Plan
WW42 ACRN GPIO virtualization Yu Wang Plan
Slimboot Loader Introduction Plan
CPU Sharing (TBD)
ACRN real-time (TBD)
vSBL Introduction (TBD)
Open Source Android (TBD) Plan
  1. 2018 IoT solution world Congress
  1. Oct’18
  2. Status: demo submitted, waiting for acceptance
  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
Best regards.
Tel: +86-21-6116 7445
MP: +86-1364 1793 689

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