From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MxLW2-0005H6-N5 for qemu-devel@nongnu.org; Mon, 12 Oct 2009 10:04:46 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MxLVy-0005Et-1H for qemu-devel@nongnu.org; Mon, 12 Oct 2009 10:04:46 -0400 Received: from [199.232.76.173] (port=46253 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MxLVx-0005Ep-SO for qemu-devel@nongnu.org; Mon, 12 Oct 2009 10:04:41 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:39486) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MxLVx-000320-CG for qemu-devel@nongnu.org; Mon, 12 Oct 2009 10:04:41 -0400 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e6.ny.us.ibm.com (8.14.3/8.13.1) with ESMTP id n9CE9e65012412 for ; Mon, 12 Oct 2009 10:09:40 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n9CE4eQd255852 for ; Mon, 12 Oct 2009 10:04:40 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n9CE4dhv028194 for ; Mon, 12 Oct 2009 10:04:40 -0400 Message-ID: <4AD33774.1030001@us.ibm.com> Date: Mon, 12 Oct 2009 09:04:36 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [PATCH v2 9/9] Add -kvm option References: <1254953315-5761-2-git-send-email-glommer@redhat.com> <1254953315-5761-3-git-send-email-glommer@redhat.com> <1254953315-5761-4-git-send-email-glommer@redhat.com> <1254953315-5761-5-git-send-email-glommer@redhat.com> <1254953315-5761-6-git-send-email-glommer@redhat.com> <1254953315-5761-7-git-send-email-glommer@redhat.com> <1254953315-5761-8-git-send-email-glommer@redhat.com> <1254953315-5761-9-git-send-email-glommer@redhat.com> <1254953315-5761-10-git-send-email-glommer@redhat.com> <4ACD1D92.8080607@us.ibm.com> <20091007231405.GQ8092@mothafucka.localdomain> <4ACD2414.9000401@codemonkey.ws> <4AD319F6.70506@redhat.com> In-Reply-To: <4AD319F6.70506@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: Andre Przywara , Glauber Costa , qemu-devel@nongnu.org Gerd Hoffmann wrote: > On 10/08/09 01:28, Anthony Liguori wrote: >> Glauber Costa wrote: >>> even if we have qdev on the irq controllers, one could still come up >>> with >>> situations in which we'd like to force the use of one device over >>> another. >> >> Right, my assumption is that the devices will have different qdev names >> and therefore a user can select which one gets used. >> >> Right now, -device is just additive. I'm not sure the best way to >> express something like, replace this existing device with this new >> device. Maybe some trickery with id=. Gerd, any thoughts? > > -M $machine gives you a barebone machine with all core devices which > belong to it. You can't easily remove and/or replace devices. > Especially not something central as the IRQ controller. But also no > other core components, i.e. you wouldn't stick a piix4 ide controller > into a Q35 machine. Just say 'no'. This seems fundamentally flawed to me. If you cannot remove a device from a machine using command line options, then how do we support something like -net none? Do we make the default machine not contain a nic? The value of a machine type to a user is that it presents a useful machine--not a barebones machine. A user should not have to think about which type of nic they need or whether they want to enable usb. > > That leaves two options: > > (1) create two devices, create new machines which use the kvm > versions (aka -M pc-kvm). > (2) make using the in-kernel kvm code a device property. (3) Add the ability to remove device from a machine type. -- Regards, Anthony Liguori