From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48526) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYPTm-000840-3X for qemu-devel@nongnu.org; Tue, 23 Feb 2016 21:47:07 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aYPTk-0007dM-VZ for qemu-devel@nongnu.org; Tue, 23 Feb 2016 21:47:06 -0500 Received: from ozlabs.org ([2401:3900:2:1::2]:42513) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYPTk-0007cX-KV for qemu-devel@nongnu.org; Tue, 23 Feb 2016 21:47:04 -0500 Date: Wed, 24 Feb 2016 12:52:19 +1100 From: David Gibson Message-ID: <20160224015219.GE2808@voom.fritz.box> References: <1455556228-232720-1-git-send-email-imammedo@redhat.com> <878u2lhi8i.fsf@blackfin.pond.sub.org> <20160216113655.2bbb9988@nial.brq.redhat.com> <20160218033952.GG15224@voom.fritz.box> <20160218113739.64b02461@nial.brq.redhat.com> <20160219043848.GZ15224@voom.fritz.box> <20160219164911.091b4351@nial.brq.redhat.com> <20160222025432.GD2808@voom.fritz.box> <20160223104645.6b64f60c@nial.brq.redhat.com> <20160223212620.GF3901@thinpad.lan.raisama.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="O2gaCPMlz9o7j9TI" Content-Disposition: inline In-Reply-To: <20160223212620.GF3901@thinpad.lan.raisama.net> Subject: Re: [Qemu-devel] [RFC] QMP: add query-hotpluggable-cpus List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: lvivier@redhat.com, thuth@redhat.com, Peter Krempa , aik@ozlabs.ru, qemu-devel@nongnu.org, agraf@suse.de, Markus Armbruster , pbonzini@redhat.com, abologna@redhat.com, bharata@linux.vnet.ibm.com, Igor Mammedov , afaerber@suse.de --O2gaCPMlz9o7j9TI Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Feb 23, 2016 at 06:26:20PM -0300, Eduardo Habkost wrote: > On Tue, Feb 23, 2016 at 10:46:45AM +0100, Igor Mammedov wrote: > > On Mon, 22 Feb 2016 13:54:32 +1100 > > David Gibson wrote: > [...] > > > This is why Eduardo suggested - and I agreed - that it's probably > > > better to implement the "1st layer" as an internal structure/interface > > > only, and implement the 2nd layer on top of that. When/if we need to > > > we can revisit a user-accessible interface to the 1st layer. > > We are going around QOM based CPU introspecting interface for > > years now and that's exactly what 2nd layer is, just another > > implementation. I've just lost hope in this approach. > >=20 > > What I'm suggesting in this RFC is to forget controversial > > QOM approach for now and use -device/device_add + QMP introspection, >=20 > You have a point about it looking controversial, but I would like > to understand why exactly it is controversial. Discussions seem > to get stuck every single time we try to do something useful with > the QOM tree, and I don't undertsand why. Yeah, I've noticed that too, and I don't know why either. It's pretty frustrating, since on power we don't have the option of sticking with the old cpu hotplug interface for now. So I really have no idea how to move things forwards towards a workable approach. > > i.e. completely split interface from how boards internally implement > > CPU hotplug. >=20 > A QOM-based interface may still split the interface from how > boards internally implement CPU hotplug. They don't need to > affect the device tree of the machine, we just need to create QOM > objects or links at predictable paths, that implement certain > interfaces. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --O2gaCPMlz9o7j9TI Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJWzQzTAAoJEGw4ysog2bOSXI8P/icbwaJ4uciePzFgz4ZMPS8P axRATlzgjDSPveO7C073YcGst5CsLyIF3YRj6vbxLv2AKa2M6lhZb4z6C/gClXYH /EpqlNXrXma2hOqL85ZhYglD7i42HJdjjTab/FT+cHq6ijEtavDc7E9VNMotWUHe gltYALRVn1QYnG4rkn+xhr9OL9jgfBWz9V9LTBcTcWc2D4R0ou/dxyj40tEn6C76 ND/WMzx91c0/3FtMoTEVYlvccjwZPtfLve0XMtZmdxRIIzLTIFwGTwOcNodsz7L+ dYX8qY0b6htVLtx45F+Gd0Qjw+tyCGyTJjvUG5gtQgQ0igS9cXhE6WzEMBQhKtVJ beNX2iAeiEtGF+C3poseV/oPKNhH5deWxV3BS9Tu70DwHe+ZEegu6Bwg2zZwYrXr Gq19DouUYrpPYXsfYgoxGnNsuXzkndfAvxawqbPZDzr3H185vk9rSO1Q9tvQio/W Br4u9hrHzWtuZVT1eAcUjmbtWvI4EEuNSsSgt93Itip7t8VX7Zds+kMea+T0ZhId ccXrL3gtZrtxLdM/PLaa0zF/Vzt/r+NmiyW/hZbjwXXaS3lZu++Jo6/iMqH3mXvl K6SZzvmJ71LixmTv/1aVm48MTYN/jiBl/csxt9eylZFKYph/KI9+n+L7hMGt7Zv7 pCP7RdyH5ZKTbdNsroh0 =nrSI -----END PGP SIGNATURE----- --O2gaCPMlz9o7j9TI--