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Comment: Today's notes on the draft

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Title: What HV technology can do for future automotive systems.

Motivation: Why to use HV:


Opinions on the high level purpose of the paper.

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Feedback: "in user-level functionality" is this emulation code in the HV or what is meant byzk user level?  Can we clarify?


  1. Surveillance, Monitoring, Isolation (Timing and Spatial) and all that

To establish well-defined behavior of SW at platform-level several design paradigms can be followed, where each prioritize different aspects, e.g., fault-detection versus information hiding, high-performance vs. good worst-case timing behavior. At the bottom-line it appears that one of the fundamental principles of establishing safe and secure execution environments is about isolation and surveillance.

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Open Asymmetric Multiprocessing - OpenAMP - messaging standards built on top of this...  Often the implementation uses the hardware capabilities for mailboxes/links etc.

Cache locking?

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New ARM designs/solutions need to be considered - ARM engineers can help.


Sharing Devices (and VIRTIO)

Methods and implications

Artem wants to cover Performance issues on device sharing.  General, not VIRTIO specific.

Maybe first chapter is rather named paravirtualization techniques?

and then VIRTIO is a sub chapter.  Or its own chapter.


Kai & Gunnar

Content:

As already outlined, the VMM component in the system needs to provide a virtual platform to the guest operating system. This includes a set of common devices that a VM typically needs, including console, network and block devices. When an OS runs bare-metal on the hardware, a regular driver is used to drive, for example, the network interface controller (NIC). The interface between the NIC and the OS is based on memory-mapped IO which is the optimal way of communicating with a physical device. When providing a VM a virtual device, the memory-mapped approach is not the most efficient one. First, because this requires the so-called trap-and-emulate technique where each access to the MMIO-region is trapped into the VMM and second because the NIC needs to be emulated by the VMM which is actually more complicated than required for this use-case. It is much easier in terms of required software as well as offers more performance when using a device for a VM that is particularly made for being used in Vms.

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SUMMARY: More unique features possible with an HV




Security implications

Artem has some objections to VIRTIO from security point of view.  It could be included inside this text or as a sub-chapter of this chapter.



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ALL SUMMARIES TOGETHER (AS OUTLINE)

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SUMMARY: Hardware support for virtualization is included in modern processors

Surveillance, Isolation (Timing and Spatial) and all that


SUMMARY: Explain isolation, timing, spatial

Inter-core communication

Matti, Dimitri to write (Dmitry suggested that Matti does it better)


Sharing Devices -- Virtio

SUMMARY: The need for virtual platform. Shortly compare full hardware virtualization/emulation with… not doing that.

SUMMARY: The current contents of VIRTIO spec

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