From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56531) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V6fFw-0006Cd-C3 for qemu-devel@nongnu.org; Tue, 06 Aug 2013 07:16:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V6fFq-0003cB-Di for qemu-devel@nongnu.org; Tue, 06 Aug 2013 07:16:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:1850) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V6fFq-0003c4-4r for qemu-devel@nongnu.org; Tue, 06 Aug 2013 07:16:42 -0400 Date: Tue, 6 Aug 2013 14:16:37 +0300 From: Gleb Natapov Message-ID: <20130806111637.GU8218@redhat.com> References: <51FFD6CE.5090302@redhat.com> <20130805182628.GC4244@redhat.com> <20130806072152.GK10891@redhat.com> <20130806083309.GA11051@redhat.com> <20130806083625.GF8218@redhat.com> <20130806092148.GC11051@redhat.com> <20130806093247.GL8218@redhat.com> <20130806101953.GC13680@redhat.com> <20130806104442.GR8218@redhat.com> <5200D806.5030509@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: <5200D806.5030509@suse.de> Subject: Re: [Qemu-devel] [SeaBIOS] [PATCH] don't expose pvpanic device in the UI List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andreas =?utf-8?Q?F=C3=A4rber?= Cc: Marcel Apfelbaum , seabios@seabios.org, qemu-devel@nongnu.org, "Michael S. Tsirkin" , Gerd Hoffmann , Anthony Liguori , Paolo Bonzini On Tue, Aug 06, 2013 at 01:03:34PM +0200, Andreas F=C3=A4rber wrote: > Am 06.08.2013 12:44, schrieb Gleb Natapov: > > On Tue, Aug 06, 2013 at 01:19:53PM +0300, Michael S. Tsirkin wrote: > >>>> It's a QEMU issue, devices that are added with -device are > >>>> documented in -device help and removed by dropping them from > >>>> command line. Devices added by default have no way to > >>>> be dropped from QOM except -nodefaults. > >>>> > >>> Are you saying that because pvpanic is added automatically QEMU -devi= ce > >>> help does not print help about it? Why not fix that? What QEMU --help > >>> issues has to do with deciding which devices should or should not be > >>> present by default? > >> > >> No, I'm saying what I said: that there's no way to remove a device > >> added by default except -nodefaults, and no way to > >> find out what does -nodefaults exclude so you > >> can add things you need back selectively. > >> > > And what are the rules that govern device exclusion from -nodefaults > > list? Why -nodefaults does not create empty machine? >=20 > We have -M none to create an empty machine. >=20 > FWIW -M q35 does not create all Q35 devices, there's -readconfig > docs/q35-chipset.cfg for the rest. The criteria certainly is not > migratability, since ICH9 AHCI (part of -M q35) is unmigratable, > unfortunately. > One practical reason not to create everything via config is that we > cannot create SysBusDevices via -device when they require MMIO mapping > or IRQ setup. For ISADevices such as pvpanic that's not a problem. > Anthony has proposed QOM'ifying MemoryRegions and qemu_irq as solution > to do the wiring-up from command line or config file, but those attempts > got stuck a long time ago. >=20 But -M creates not only things that cannot be created from a command line, it includes some default set of devices, so what is the criteria for those? -- Gleb.