From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 00/18] KVM: PPC: Virtualize Gekko guests Date: Sun, 07 Feb 2010 18:22:10 +0200 Message-ID: <4B6EE8B2.80009@redhat.com> References: <1265298925-31954-1-git-send-email-agraf@suse.de> <4B6EB7F6.10304@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "kvm-ppc@vger.kernel.org" , "kvm@vger.kernel.org" To: Alexander Graf Return-path: Received: from mx1.redhat.com ([209.132.183.28]:46952 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755971Ab0BGQWO (ORCPT ); Sun, 7 Feb 2010 11:22:14 -0500 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 02/07/2010 05:49 PM, Alexander Graf wrote: > Am 07.02.2010 um 13:54 schrieb Avi Kivity : > >> On 02/04/2010 05:55 PM, Alexander Graf wrote: >>> In an effort to get KVM on PPC more useful for other userspace users >>> than >>> Qemu, I figured it'd be a nice idea to implement virtualization of the >>> Gekko CPU. >>> >>> The Gekko is the CPU used in the GameCube. In a slightly more modern >>> fashion it lives on in the Wii today. >>> >>> Using this patch set and a modified version of Dolphin, I was able to >>> virtualize simple GameCube demos on a 970MP system. >>> >>> As always, while getting this to run I stumbled across several broken >>> parts and fixed them as they came up. So expect some bug fixes in this >>> patch set too. >>> >> >> This is halfway into emulation rather than virtualization. What does >> performance look like when running fpu intensive applications? > > It is for the FPU. It is not for whatever runs on the CPU. > > I haven't benchmarked things so far, > > The only two choices I have to get this running is in-kernel emulation > or userspace emulation. According to how x86 deals with things I > suppose full state transition to userspace and continuing emulation > there isn't considered a good idea. So I went with in-kernel. It's not a good idea for the kernel either, if it happens all the time. If a typical Gekko application uses the fpu and the emulated instructions intensively, performance will suck badly (as in: qemu/tcg will be faster). -- error compiling committee.c: too many arguments to function