Re: [Stratos-dev] Enabling hypervisor agnosticism for VirtIO backends

[Alex Bennée <alex.bennee@xxxxxxxxxx>]

Christopher Clark <christopher.w.clark@xxxxxxxxx> writes:

> On Sun, Sep 5, 2021 at 7:24 PM AKASHI Takahiro via Stratos-dev 
> <stratos-dev@xxxxxxxxxxxxxxxxxxx> wrote:
>
>  Alex,
>
>  On Fri, Sep 03, 2021 at 10:28:06AM +0100, Alex Benn??e wrote:
<snip>
>
>  In configuration phase of virtio device, the latency won't be a big matter.
>  In device operations (i.e. read/write to block devices), if we can
>  resolve 'mmap' issue, as Oleksandr is proposing right now, the only issue is
>  how efficiently we can deliver notification to the opposite side. Right?
>  And this is a very common problem whatever approach we would take.
>
>  Anyhow, if we do care the latency in my approach, most of virtio-proxy-
>  related code can be re-implemented just as a stub (or shim?) library
>  since the protocols are defined as RPCs.
>  In this case, however, we would lose the benefit of providing "single binary"
>  BE.
>  (I know this is is an arguable requirement, though.)

The proposal for a single binary would always require something to shim
between hypervisors. This is still an area of discussion though. Having
a compile time selectable approach is practically unavoidable for "bare
metal" backends though because there are no other processes/layers that
communication with the hypervisor can be delegated to.

>
>  # Would we better discuss what "hypervisor-agnosticism" means?
>
> Is there a call that you could recommend that we join to discuss this and the 
> topics of this thread?
> There is definitely interest in pursuing a new interface for Argo that can be 
> implemented in other hypervisors and enable guest binary
> portability between them, at least on the same hardware architecture,
> with VirtIO transport as a primary use case.

There is indeed ;-)

We have a regular open call every two week for the Stratos project which
you are welcome to attend. You can find the details on the project
overview page:

  https://linaro.atlassian.net/wiki/spaces/STR/overview

we regularly have teams from outside the project present their work as well.

> The notes from the Xen Summit Design Session on VirtIO Cross-Project BoF for 
> Xen and Guest OS, which include context about the
> several separate approaches to VirtIO on Xen, have now been posted here:
> https://lists.xenproject.org/archives/html/xen-devel/2021-09/msg00472.html

Thanks for the link - looks like a very detailed summary.

>
> Christopher
>
>  
>  -Takahiro Akashi


-- 
Alex Bennée