From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [Qemu-devel] [PATCH] Add definitions for current cpu models.. Date: Tue, 19 Jan 2010 22:15:48 +0000 Message-ID: <20100119221548.GC11920@shareable.org> References: <4B549016.6090501@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: KVM list , qemu-devel@nongnu.org, "Przywara, Andre" To: john cooper Return-path: Received: from mail2.shareable.org ([80.68.89.115]:39689 "EHLO mail2.shareable.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754281Ab0ASWPt (ORCPT ); Tue, 19 Jan 2010 17:15:49 -0500 Content-Disposition: inline In-Reply-To: <4B549016.6090501@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: john cooper wrote: > As before a cpu feature 'check' option is added which warns when > feature flags (either implicit in a cpu model or explicit on the > command line) would have otherwise been quietly unavailable to a > guest: > > # qemu-system-x86_64 ... -cpu Nehalem,check > warning: host cpuid 0000_0001 lacks requested flag 'sse4.2' [0x00100000] > warning: host cpuid 0000_0001 lacks requested flag 'popcnt' [0x00800000] That's a nice feature. Can we have a 'checkfail' option which refuses to run if a requested capability isn't available? Thanks. I foresee wanting to iterate over the models and pick the latest one which a host supports - on the grounds that you have done the hard work of ensuring it is a reasonably good performer, while "probably" working on another host of similar capability when a new host is made available. -- Jamie From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NXMMd-00011y-GQ for qemu-devel@nongnu.org; Tue, 19 Jan 2010 17:15:55 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NXMMZ-00010a-S7 for qemu-devel@nongnu.org; Tue, 19 Jan 2010 17:15:55 -0500 Received: from [199.232.76.173] (port=55943 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NXMMZ-00010W-OJ for qemu-devel@nongnu.org; Tue, 19 Jan 2010 17:15:51 -0500 Received: from mail2.shareable.org ([80.68.89.115]:58836) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NXMMZ-0002nL-7g for qemu-devel@nongnu.org; Tue, 19 Jan 2010 17:15:51 -0500 Date: Tue, 19 Jan 2010 22:15:48 +0000 From: Jamie Lokier Subject: Re: [Qemu-devel] [PATCH] Add definitions for current cpu models.. Message-ID: <20100119221548.GC11920@shareable.org> References: <4B549016.6090501@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B549016.6090501@redhat.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: john cooper Cc: "Przywara, Andre" , qemu-devel@nongnu.org, KVM list john cooper wrote: > As before a cpu feature 'check' option is added which warns when > feature flags (either implicit in a cpu model or explicit on the > command line) would have otherwise been quietly unavailable to a > guest: > > # qemu-system-x86_64 ... -cpu Nehalem,check > warning: host cpuid 0000_0001 lacks requested flag 'sse4.2' [0x00100000] > warning: host cpuid 0000_0001 lacks requested flag 'popcnt' [0x00800000] That's a nice feature. Can we have a 'checkfail' option which refuses to run if a requested capability isn't available? Thanks. I foresee wanting to iterate over the models and pick the latest one which a host supports - on the grounds that you have done the hard work of ensuring it is a reasonably good performer, while "probably" working on another host of similar capability when a new host is made available. -- Jamie