From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 2D5691A03D6 for ; Thu, 18 Feb 2016 09:31:44 +1100 (AEDT) Date: Wed, 17 Feb 2016 14:31:41 -0800 From: Greg Kroah-Hartman To: Steven Royer Cc: Jonathan Corbet , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Arnd Bergmann , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Steven Royer Subject: Re: [PATCH] add POWER Virtual Management Channel driver Message-ID: <20160217223141.GA16341@kroah.com> References: <1455655393-3137-1-git-send-email-seroyer@linux.vnet.ibm.com> <20160216221822.GA32255@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Feb 17, 2016 at 03:18:26PM -0600, Steven Royer wrote: > On 2016-02-16 16:18, Greg Kroah-Hartman wrote: > >On Tue, Feb 16, 2016 at 02:43:13PM -0600, Steven Royer wrote: > >>From: Steven Royer > >> > >>The ibmvmc driver is a device driver for the POWER Virtual Management > >>Channel virtual adapter on the PowerVM platform. It is used to > >>communicate with the hypervisor for virtualization management. It > >>provides both request/response and asynchronous message support through > >>the /dev/ibmvmc node. > > > >What is the protocol for that device node? > The protocol is not currently published. I am pushing on getting it > published, but that process will take time. If you have a PowerVM system > with NovaLink, it would not be hard to reverse engineer it... If you don't > have a PowerVM system, then this driver isn't interesting anyway... You can't just expect us to review this code without at least having a clue as to how it is supposed to work? > >Where is the documentation here? Why does this have to be a character > >device? Why can't it fit in with other drivers of this type? > This is a character device for historical reasons. The short version is > that this driver is a clean-room rewrite of an AIX driver which made it a > character device. The user space application was ported from AIX to Linux > and it is convenient to have the AIX and Linux drivers match behavior where > possible. Note that we don't let random userspace applications dictate kernel api decisions, please make the best choice for this interface without being influenced by AIX. > >>+/* > >>+ * IBM Power Systems Virtual Management Channel Support. > >>+ * > >>+ * Copyright (c) 2004, 2016 IBM Corp. > >>+ * Dave Engebretsen engebret@us.ibm.com > >>+ * Steven Royer seroyer@linux.vnet.ibm.com > >>+ * Adam Reznechek adreznec@linux.vnet.ibm.com > >>+ * > >>+ * This program is free software; you can redistribute it and/or > >>+ * modify it under the terms of the GNU General Public License > >>+ * as published by the Free Software Foundation; either version 2 > >>+ * of the License, or (at your option) any later version. > > > >I have to ask, but do you really mean "or any later version"? > This actually matches closely to other similar PowerVM virtual device > drivers, like ibmvscsi or ibmveth. That did not answer the question, picking a license in a cargo-cult manner is not a wise decision :(