From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 7/7] [v2] drivers/misc: introduce Freescale hypervisor management driver Date: Fri, 3 Jun 2011 17:28:43 +0200 Message-ID: <201106031728.43707.arnd@arndb.de> References: <1306953337-15698-1-git-send-email-timur@freescale.com> <201106012340.14237.arnd@arndb.de> <20110601172412.761ff799@schlenkerla.am.freescale.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110601172412.761ff799@schlenkerla.am.freescale.net> Sender: linux-console-owner@vger.kernel.org List-ID: Content-Type: Text/Plain; charset="us-ascii" To: Scott Wood Cc: Timur Tabi , kumar.gala@freescale.com, linux-kernel@vger.kernel.org, akpm@kernel.org, linux-console@vger.kernel.org, greg@kroah.com, linuxppc-dev@lists.ozlabs.org On Thursday 02 June 2011, Scott Wood wrote: > I wanted to have the hypervisor take an update dtb (we already have special > meta-properties for things like deletion as part of the hv config > mechanism). But others on the project wanted to keep it simple, and so > get/set property it was. :-/ > > It's unlikely to change at this point without a real need. > > As for a filesystem interface, it's not a good match either. > You can't iterate over anything to read out the full tree from the hv. kexec iterates over /proc/device-tree to create a dts blob. > You can't delete anything. rm, rmdir > You can't create empty nodes. mkdir > The hv interface was meant to enable some specific management actions, > rather than to provide general device tree access. This driver is a thin > wrapper around the management hcalls. A file system would be a slightly more abstract interface to do the same thing, I gues. > There would still be other ioctls needed for starting/stopping the > partition, etc. Right, although you could model them as a file interface as well. KVMfs is one example doing that. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.126.171]) by ozlabs.org (Postfix) with ESMTP id 8DD64B6FB4 for ; Sat, 4 Jun 2011 01:28:52 +1000 (EST) From: Arnd Bergmann To: Scott Wood Subject: Re: [PATCH 7/7] [v2] drivers/misc: introduce Freescale hypervisor management driver Date: Fri, 3 Jun 2011 17:28:43 +0200 References: <1306953337-15698-1-git-send-email-timur@freescale.com> <201106012340.14237.arnd@arndb.de> <20110601172412.761ff799@schlenkerla.am.freescale.net> In-Reply-To: <20110601172412.761ff799@schlenkerla.am.freescale.net> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Message-Id: <201106031728.43707.arnd@arndb.de> Cc: greg@kroah.com, kumar.gala@freescale.com, linux-kernel@vger.kernel.org, akpm@kernel.org, linux-console@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Timur Tabi List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thursday 02 June 2011, Scott Wood wrote: > I wanted to have the hypervisor take an update dtb (we already have special > meta-properties for things like deletion as part of the hv config > mechanism). But others on the project wanted to keep it simple, and so > get/set property it was. :-/ > > It's unlikely to change at this point without a real need. > > As for a filesystem interface, it's not a good match either. > You can't iterate over anything to read out the full tree from the hv. kexec iterates over /proc/device-tree to create a dts blob. > You can't delete anything. rm, rmdir > You can't create empty nodes. mkdir > The hv interface was meant to enable some specific management actions, > rather than to provide general device tree access. This driver is a thin > wrapper around the management hcalls. A file system would be a slightly more abstract interface to do the same thing, I gues. > There would still be other ioctls needed for starting/stopping the > partition, etc. Right, although you could model them as a file interface as well. KVMfs is one example doing that. Arnd