From: Timur Tabi <timur@freescale•com>
To: Yoder Stuart-B08248 <B08248@freescale•com>
Cc: Wood Scott-B07421 <B07421@freescale•com>,
Alexander Graf <agraf@suse•de>,
"linuxppc-dev@ozlabs•org" <linuxppc-dev@ozlabs•org>,
Gala Kumar-B11780 <B11780@freescale•com>
Subject: Re: RFC: top level compatibles for virtual platforms
Date: Mon, 11 Jul 2011 10:45:47 -0500 [thread overview]
Message-ID: <4E1B1AAB.8010301@freescale.com> (raw)
In-Reply-To: <9F6FE96B71CF29479FF1CDC8046E150316F97F@039-SN1MPN1-003.039d.mgd.msft.net>
Yoder Stuart-B08248 wrote:
> 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.
Is there a list of these features that are 100% guaranteed to belong to a
corenet platform?
I'm just not comfortable using "corenet" as a basis for a feature set that has
nothing to do with coherency.
>> 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.
True, but I think we're on a slippery slope, here. Virtualization allows us to
create "virtual platforms" that are not well defined. Linux requires a unique
compatible string for each platform. That's easy when we ship a reference board
that has a unique name and a fixed, well-defined set of features. But with
these virtual platforms, what does the name mean?
I guess my point is back to the name "corenet". That just doesn't mean anything
to me, and I don't think it means much to anyone else, either. That's why I
think that maybe "kvm" should be in the string, to at least indicate that it's a
virtualized environment.
> 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"
That's an improvement, but I wonder if we should just keep doing what we do with
Topaz: take the actual hardware platform and add -hv to it. Of course, that
conflicts with Topaz at the moment.
--
Timur Tabi
Linux kernel developer at Freescale
--
Timur Tabi
Linux kernel developer at Freescale
next prev parent reply other threads:[~2011-07-11 15:45 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-08 18:43 RFC: top level compatibles for virtual platforms Yoder Stuart-B08248
2011-07-09 1:39 ` Tabi Timur-B04825
2011-07-09 2:42 ` Grant Likely
2011-07-11 14:36 ` Yoder Stuart-B08248
2011-07-11 14:34 ` Yoder Stuart-B08248
2011-07-11 15:45 ` Timur Tabi [this message]
2011-07-11 16:24 ` Scott Wood
2011-07-11 17:41 ` Yoder Stuart-B08248
2011-07-11 18:04 ` Scott Wood
2011-07-11 20:41 ` Yoder Stuart-B08248
2011-07-11 21:06 ` Scott Wood
2011-07-12 14:20 ` Yoder Stuart-B08248
2011-07-11 17:54 ` Timur Tabi
2011-07-11 19:59 ` Grant Likely
2011-07-11 20:06 ` Scott Wood
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