From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932223Ab3LTCih (ORCPT ); Thu, 19 Dec 2013 21:38:37 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:40441 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932174Ab3LTCig (ORCPT ); Thu, 19 Dec 2013 21:38:36 -0500 Date: Thu, 19 Dec 2013 21:38:20 -0500 From: Konrad Rzeszutek Wilk To: "H. Peter Anvin" Cc: Greg KH , Alex Williamson , linux-kernel@vger.kernel.org, gnomes@lxorguk.ukuu.org.uk, arnd@arndb.de, Alan Cox Subject: Re: [PATCH v2] misc: Reserve minor for VFIO Message-ID: <20131220023820.GG25322@phenom.dumpdata.com> References: <20131218204024.30540.55302.stgit@bling.home> <20131218210141.GA11267@kroah.com> <52B21B7E.1020307@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52B21B7E.1020307@zytor.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 18, 2013 at 02:02:38PM -0800, H. Peter Anvin wrote: > On 12/18/2013 01:01 PM, Greg KH wrote: > > On Wed, Dec 18, 2013 at 01:56:32PM -0700, Alex Williamson wrote: > >> VFIO currently allocates it's own dynamic chardev range, reserving the > >> first minor for the control part of the interface (/dev/vfio/vfio) and > >> the remainder for VFIO groups (/dev/vfio/$GROUP). This works, but it > >> doesn't support auto loading. For instance when libvirt checks for > >> VFIO support it looks for /dev/vfio/vfio, which currently doesn't > >> exist unless the vfio module is loaded. By converting the control > >> device to a misc driver and reserving a static minor, we can enable > >> auto loading. Why not have libvirt or systemctl try to load vfio first? If it does not work it would error out. Or perhaps make the loading of modules in /dev/vfio automatic? I thought it was based on the name? > >> > >> Reserving the minor is a prerequist to that conversion. Minor 196 > >> is unused by anything currently in the kernel. > >> > >> Suggested-by: Paolo Bonzini > >> Signed-off-by: Alex Williamson > >> --- > >> > >> v2: Plea for ack edition > >> > >> As Alan suspected, there's been no response from device@lanana.org, > >> so there's probably nobody monitoring it anymore. I've done due > >> diligence looking at all the callers of misc_register() in linux-next > >> and cannot find any conflicts with minor 196. If anyone wants to toss > >> me an ack or sign-off I'll be happy to bring this in through my vfio > >> tree, otherwise I'd appreciate if someone wants to take it directly. > >> Thanks! > >> > >> Documentation/devices.txt | 1 + > >> include/linux/miscdevice.h | 1 + > >> 2 files changed, 2 insertions(+) > > > > Acked-by: Greg Kroah-Hartman > > > > I think Alan Cox was the last person to man ... Alan, > are you still doing that? (Otherwise patching the file in the Linux > kernel tree seems eminently sensible... there really isn't any need to > reserve numbers for out-of-tree drivers anymore. Just another perk of > being in-tree.) > > -hpa > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/