From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Brook Subject: Re: [Qemu-devel] [RFC] allow multi-core guests: introduce cores= option to -cpu Date: Sat, 4 Jul 2009 06:58:13 +0100 Message-ID: <200907040658.14475.paul@codesourcery.com> References: <1246632116-31366-1-git-send-email-andre.przywara@amd.com> <200907031646.36268.paul@codesourcery.com> <4A4E9824.9090200@amd.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org To: Andre Przywara Return-path: Received: from mail.codesourcery.com ([65.74.133.4]:51397 "EHLO mail.codesourcery.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750796AbZGDF6N (ORCPT ); Sat, 4 Jul 2009 01:58:13 -0400 In-Reply-To: <4A4E9824.9090200@amd.com> Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: On Saturday 04 July 2009, Andre Przywara wrote: > Paul Brook wrote: > >> currently SMP guests happen to see vCPUs as different sockets. > >> Some guests (Windows comes to mind) have license restrictions and refuse > >> to run on multi-socket machines. > >> So lets introduce a "cores=" parameter to the -cpu option to let the > >> user specify the number of _cores_ the guest should see. > > > > Sounds like this should be part of the -numa option. > > Sound reasonable on the first glance, but would make it rather > complicated in real life. I suppose multi-core is far more interesting > to most of the people than multi-node, so I would opt for the easier: > -smp 2,cores=2 to specify a dual core guest. I disagree. I think it makes a sense of the topology of nodes, cores and threads to all be specified in the same place. All the options you don't specify should have sensible defaults. Paul