From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36934) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecXkr-0001Z1-4F for qemu-devel@nongnu.org; Fri, 19 Jan 2018 09:34:54 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ecXkm-0003OG-6T for qemu-devel@nongnu.org; Fri, 19 Jan 2018 09:34:53 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45046) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ecXkm-0003Nt-0H for qemu-devel@nongnu.org; Fri, 19 Jan 2018 09:34:48 -0500 Message-ID: <1516372482.3278.29.camel@redhat.com> From: Andrea Bolognani Date: Fri, 19 Jan 2018 15:34:42 +0100 In-Reply-To: <6a3fac69-c1e5-36cf-4781-5bb82b890efa@ozlabs.ru> References: <20180119050906.18930-1-aik@ozlabs.ru> <20180119051926.GI30352@umbus.fritz.box> <6a3fac69-c1e5-36cf-4781-5bb82b890efa@ozlabs.ru> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH qemu] qmp: Add qom-list-properties to list QOM object properties List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy , David Gibson Cc: qemu-devel@nongnu.org On Fri, 2018-01-19 at 17:15 +1100, Alexey Kardashevskiy wrote: > > I think the existing qom-list interface does this already. > > Nope, it does not. It takes path, not a type, so running with "-machine > none" won't help. > > > This won't solve the libvirt problem we were discussing, because it > > needs an existing instance of the object. libvirt wants to know the > > machine properties *without* instantiating an instance. > > My patch works with types, it creates an instance for a short time itself, > this is why it does not do a thing for "pseries" as it is not a type and > prints properties for the "pseries-2.12-machine" type. Yeah, I took this for a spin and can confirm that it's pretty much exactly what I was thinking about. The fact that the QMP command instantiates objects behind the scenes is not an issue, at least from libvirt's point of view: device-list-properties does the same thing and we already use it quite happily; what matters is that we can call this, along with all the other capabilities-collecting QMP commands, in one go and on a single QEMU instance. -- Andrea Bolognani / Red Hat / Virtualization