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From: Rusty Russell <rusty@rustcorp.com.au>
Subject: Re: [Qemu-devel] Re: virtio-serial: An interface for
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Date: Tue, 11 Aug 2009 08:39:28 +0930
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To: Gerd Hoffmann <kraxel@redhat.com>
Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org, "Richard W.M. Jones" <rjones@redhat.com>, virtualization@lists.linux-foundation.org, Amit Shah <amit.shah@redhat.com>

On Mon, 10 Aug 2009 07:17:54 pm Gerd Hoffmann wrote:
> On 08/10/09 08:55, Amit Shah wrote:
> >> Bad example.  Quite a lot of modern devices drivers are using dynamic
> >> major/minor numbers because they have proven to be such a pain in the
> >> butt.  That's why we have more sophisticated mechanisms like udev for
> >> userspace to make use of.
> >
> > Let me explain how we came to this numbering: we first had support for
> > 'naming' ports and the names were obtained by userspace programs by an
> > ioctl. Rusty suggested to use some numbering scheme where some ports
> > could exist at predefined locations so that we wouldn't need the naming
> > and the ioctls around it.
> 
> I think the naming is very important.

I disagree.  If you can hand out names, you can hand out numbers.  Whether
the guest chooses to put that number in sysfs or make it a minor, I don't
care.

Rusty.