From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ingo Molnar <mingo@elte.hu>
Subject: Re: Xen & VMI?
Date: Tue, 6 Mar 2007 09:52:22 +0100
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* Gerd Hoffmann <kraxel@suse.de> wrote:

> Ingo Molnar wrote:
> > btw., while we have everyone on the phone and talking ;) Technologicall=
y =

> > it would save us a whole lot of trouble in Linux if 'external' =

> > hypervisors could standardize around a single ABI - such as VMI. Is =

> > there any deep reason why Xen couldnt use VMI to talk to Linux? I =

> > suspect a range of VMI vectors could be set aside for Xen's dom0 (and =

> > other) APIs that have no current VMI equivalent - if there's broad =

> > agreement on the current 60+ base VMI vectors that center around basic =

> > x86 CPU capabilities - which make up the largest portion of our =

> > paravirtualization complexity. Pipe dream?
> =

> IIRC there was some proof-of-concept at least for xen guests.

yes - but de-facto contradicted by the Xen paravirt_ops patches sent to =

lkml ;)

> > there are already 5 major hypervisors we are going to support (in =

> > alphabetical order):
> > =

> >  - KVM
> >  - lguest
> >  - Windows
> >  - VMWare
> >  - Xen
> > =

> > the QA matrix is gonna be a _mess_.
> =

> I fail to see how xen-via-vmirom instead of xen-via-paravirt_ops =

> reduces the QA effort.  You still have 5 Hypervisors you have to test =

> against.

yes, just like we have thousands of separate PC boards to support. But =

as long as the basic ABI is the same, the QA effort on the Linux kernel =

side is alot more focused. (Distros still have 18446744073709551616 =

total combinations to QA, and have to make an educated guess to reduce =

that to a more manageable number.)

	Ingo