From: Jamie Lokier <jamie@shareable.org>
To: Amit Shah <amit.shah@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
virtualization@lists.linux-foundation.org,
Gerd Hoffmann <kraxel@redhat.com>,
kvm@vger.kernel.org, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] Re: virtio-serial: An interface for host-guest communication
Date: Thu, 20 Aug 2009 18:10:18 +0100 [thread overview]
Message-ID: <20090820171018.GA2370@shareable.org> (raw)
In-Reply-To: <20090820075539.GA5876@amit-x200.redhat.com>
Amit Shah wrote:
> > I think strings are better as numbers for identifying protocols as you
> > can work without a central registry for the numbers then.
>
> I like the way assigned numbers work: it's simpler to code, needs a
> bitmap for all the ports that fits in nicely in the config space and
> udev rules / scripts can point /dev/vmch02 to /dev/console.
How would a third party go about assigning themselves a number?
For the sake of example, imagine they develop a simple service like
"guesttop" which let's the host get a listing of guest processes.
They'll have to distributed app-specific udev rule patches for every
guest distro, which sounds like a lot of work. The app itself is
probably a very simple C program; the hardest part of making it
portable across distros would be the udev rules, which is silly.
Anyway, every other device has a name or uuid these days. You can
still use /dev/sda1 to refer to your boot partition, but LABEL=boot is
also available if you prefer. Isn't that the ethos these days?
Why not both? /dev/vmch05 if you prefer, plus symlink
/dev/vmch-guesttop -> /dev/vmch05 if name=guesttop was given to QEMU.
If you do stay with numbers only, note that it's not like TCP/UDP port
numbers because the number space is far smaller. Picking a random
number that you hope nobody else uses is harder.
... Back to technical bits. If config space is tight, use a channel!
Dedicate channel 0 to control, used to fetch the name (if there is
one) for each number.
-- Jamie
next prev parent reply other threads:[~2009-08-20 17:10 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-27 18:04 [Qemu-devel] virtio-serial: An interface for host-guest communication Amit Shah
2009-07-27 18:04 ` [Qemu-devel] [PATCH 1/1] virtio_serial: A char device for simple guest <-> host communication Amit Shah
2009-07-27 18:04 ` [Qemu-devel] [PATCH 1/3] virtio-serial: virtio device for simple host <-> guest communication Amit Shah
2009-07-27 18:04 ` [Qemu-devel] [PATCH 2/3] vnc: add a is_vnc_active() helper Amit Shah
2009-07-27 18:04 ` [Qemu-devel] [PATCH 3/3] virtio-serial: vnc: support for sending / receiving guest clipboard Amit Shah
2009-08-05 0:03 ` [Qemu-devel] Re: [PATCH 1/1] virtio_serial: A char device for simple guest <-> host communication Rusty Russell
2009-08-05 5:12 ` Amit Shah
2009-08-05 9:58 ` Amit Shah
2009-07-27 20:22 ` [Qemu-devel] Re: virtio-serial: An interface for host-guest communication Anthony Liguori
2009-07-27 20:32 ` Daniel P. Berrange
2009-07-27 20:37 ` Anthony Liguori
2009-07-27 20:46 ` Jamie Lokier
2009-07-27 23:44 ` Anthony Liguori
2009-07-28 10:36 ` Amit Shah
[not found] ` <4A6F0048.1000103@codemonkey.ws>
2009-07-29 7:44 ` Amit Shah
2009-07-29 7:48 ` Gleb Natapov
2009-08-05 18:00 ` Jamie Lokier
[not found] ` <20090728140029.GA16067@amd.home.annexia.org>
2009-07-28 14:48 ` Anthony Liguori
2009-07-28 14:55 ` Richard W.M. Jones
2009-07-28 15:00 ` Anthony Liguori
2009-08-03 19:57 ` Anthony Liguori
2009-08-05 17:57 ` Jamie Lokier
2009-08-05 18:00 ` Anthony Liguori
2009-08-06 10:38 ` Amit Shah
2009-08-06 13:29 ` Anthony Liguori
2009-08-06 13:41 ` Amit Shah
2009-08-06 13:58 ` Anthony Liguori
2009-08-06 14:04 ` Amit Shah
2009-08-06 17:37 ` Jamie Lokier
2009-08-07 6:38 ` Amit Shah
2009-08-07 14:14 ` Anthony Liguori
2009-08-10 6:55 ` Amit Shah
2009-08-10 9:47 ` Gerd Hoffmann
2009-08-10 13:02 ` Anthony Liguori
2009-08-10 14:02 ` Gerd Hoffmann
2009-08-10 14:20 ` Anthony Liguori
2009-08-10 15:34 ` Gerd Hoffmann
2009-08-10 16:59 ` Anthony Liguori
2009-08-10 17:27 ` Anthony Liguori
2009-08-12 18:27 ` Paul Brook
2009-08-14 8:15 ` Amit Shah
2009-08-14 13:29 ` Anthony Liguori
2009-08-14 13:41 ` Amit Shah
2009-08-20 13:42 ` Amit Shah
2009-08-20 14:25 ` Daniel P. Berrange
2009-08-20 14:38 ` Amit Shah
2009-08-20 14:42 ` Amit Shah
2009-08-14 13:49 ` Gerd Hoffmann
2009-08-14 16:25 ` Anthony Liguori
2009-08-20 7:31 ` Rusty Russell
2009-08-20 7:44 ` Gerd Hoffmann
2009-08-20 7:55 ` Amit Shah
2009-08-20 17:10 ` Jamie Lokier [this message]
2009-08-25 12:43 ` Rusty Russell
2009-08-25 13:00 ` Gerd Hoffmann
2009-08-10 14:20 ` Anthony Liguori
2009-08-10 23:09 ` Rusty Russell
2009-08-11 0:16 ` Anthony Liguori
2009-08-10 14:27 ` Anthony Liguori
2009-08-10 15:57 ` Gerd Hoffmann
2009-08-06 10:35 ` Amit Shah
2009-08-05 18:32 ` Richard W.M. Jones
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