From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:60198) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TipAo-0001vd-UB for qemu-devel@nongnu.org; Wed, 12 Dec 2012 11:28:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TipAf-0004s0-4v for qemu-devel@nongnu.org; Wed, 12 Dec 2012 11:28:42 -0500 Received: from cantor2.suse.de ([195.135.220.15]:45553 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TipAe-0004ru-Sl for qemu-devel@nongnu.org; Wed, 12 Dec 2012 11:28:33 -0500 Message-ID: <50C8B0AC.7010500@suse.de> Date: Wed, 12 Dec 2012 17:28:28 +0100 From: =?ISO-8859-1?Q?Andreas_F=E4rber?= MIME-Version: 1.0 References: <1355317734-55761-1-git-send-email-jfrei@linux.vnet.ibm.com> <1355317734-55761-4-git-send-email-jfrei@linux.vnet.ibm.com> <50C88BED.6000000@suse.de> <50C89D30.4020508@linux.vnet.ibm.com> In-Reply-To: <50C89D30.4020508@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 3/3] S390: Enable -cpu help and QMP query-cpu-definitions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Viktor Mihajlovski , Alexander Graf Cc: Heinz Graalfs , qemu-devel , Christian Borntraeger , Jens Freimann , Cornelia Huck , Einar Lueck , Richard Henderson Am 12.12.2012 16:05, schrieb Viktor Mihajlovski: > On 12/12/2012 02:51 PM, Andreas F=E4rber wrote: >>> + (*cpu_fprintf)(f, "s390 %16s\n", "[host]"); >> >> Note that the square-bracket notation was specific to x86 when it >> distinguished between built-in and config-based models. >> > OK, since libvirt capable of dealing with s390 cpu models will > never see this, we can change it any way that is wanted. > So, host without brackets? Yes, but see below... >> "host" only makes sense for KVM, not for TCG. So we would need one oth= er >> placeholder model for libvirt. > see my reply to Alex' comment: the placeholder name must be chosen > carefully, i.e. future-proof On further thoughts, didn't we discuss that the issue libvirt wants to address is that migration from z10 to z9 must fail? That's not solved with -cpu host, we would need two other models then. IMO ideally -cpu host should have the same semantics as on x86, that is passing the host features through mostly 1:1. IIUC there is currently no way to not do so? What about future-wise having -cpu host not be a subclass and instead behaving like Alex' -cpu best, given the above semantics? What I am just worried about with this patch is cementing the use of -cpu host into libvirt when that is not a mid-term solution. Andreas --=20 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imend=F6rffer; HRB 16746 AG N=FCrnbe= rg