RFC: top level compatibles for virtual platforms

[Yoder Stuart-B08248]

> -----Original Message-----
> From: Tabi Timur-B04825
> Sent: Friday, July 08, 2011 8:39 PM
> To: Yoder Stuart-B08248
> Cc: Grant Likely; Benjamin Herrenschmidt; Gala Kumar-B11780; Wood Scott-B07421; Alexander
> Graf; linuxppc-dev at ozlabs.org
> Subject: Re: RFC: top level compatibles for virtual platforms
> 
> On Fri, Jul 8, 2011 at 1:43 PM, Yoder Stuart-B08248 <B08248 at freescale.com> wrote:
> 
> >   "MPC85xxDS" - for a virtual machine for the e500v2 type platforms
> >                 and would support 85xx targets, plus P2020, P1022,etc
> >
> >   "corenet-32-ds" - for a virtual machine similar to the 32-bit P4080
> >                     platforms
> >
> >   "corenet-64-ds" - for a virtual machine based on a 64-bit corenet
> >                     platform
> 
> I think we should drop the "DS" because that's a name applied to certain Freescale reference
> boards.
> 
> Is being a CoreNet board really something meaningful with respect to KVM?  I don't see the
> connection.

We're talking about what would be meaningful to Linux as a guest on
this platform here--  Corenet-based SoCs are similar 
in various ways, like using msgsnd for IPIs, having external proxy
support, etc.

A corenet platform created by a QEMU/KVM looks similar
to other corenet SoCs.   So, I'm trying to find some generic
compatible string that describes this platform.

> Also, if these are KVM creations, shouldn't there be a "kvm" in the compatible string
> somewhere?

There is nothing KVM specific about these platforms.  Any hypervisor
could create a similar virtual machine.

A guest OS can determine specific info about the hypervisor it is
running on by looking at the /hypervisor node on the device
tree.

We could put a generic -hv extension to indicate that this is
a virtual platform.

 "mpc85xx-hv"
 "corenet-32-hv"
 "corenet-64-hv"

Stuart