From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCHv3 RFC] virtio-pci: flexible configuration layout
Date: Wed, 30 Nov 2011 10:14:42 +0200
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To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Krishna Kumar <krkumar2@in.ibm.com>, kvm@vger.kernel.org, Pawel Moll <pawel.moll@arm.com>, Wang Sheng-Hui <shhuiw@gmail.com>, Alexey Kardashevskiy <aik@ozlabs.ru>, lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>, virtualization@lists.linux-foundation.org, Christian Borntraeger <borntraeger@de.ibm.com>, Sasha Levin <levinsasha928@gmail.com>, Amit Shah <amit.shah@redhat.com>
List-Id: virtualization@lists.linuxfoundation.org

On Wed, Nov 30, 2011 at 10:10:22AM +1030, Rusty Russell wrote:
> On Mon, 28 Nov 2011 11:15:31 +0200, Sasha Levin <levinsasha928@gmail.com> wrote:
> > On Mon, 2011-11-28 at 11:25 +1030, Rusty Russell wrote:
> > > I'd like to see kvmtools remove support for legacy mode altogether,
> > > but they probably have existing users.
> > 
> > While we can't simply remove it right away, instead of mixing our
> > implementation for both legacy and new spec in the same code we can
> > split the virtio-pci implementation into two:
> > 
> > 	- virtio/virtio-pci-legacy.c
> > 	- virtio/virtio-pci.c
> > 
> > At that point we can #ifdef the entire virtio-pci-legacy.c for now and
> > remove it at the same time legacy virtio-pci is removed from the kernel.
> 
> Hmm, that might be neat, but we can't tell the driver core to try
> virtio-pci before virtio-pci-legacy, so we need detection code in both
> modules (and add a "force" flag to virtio-pci-legacy to tell it to
> accept the device even if it's not a legacy-only one).

This flag might need to be per device ideally, which is tricky ...

> 
> Then it should work...
> Cheers,
> Rusty.

One also wonders whether and how this will work on other OS-es.

-- 
MST