From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NfFnN-0006rQ-8p for qemu-devel@nongnu.org; Wed, 10 Feb 2010 11:52:09 -0500 Received: from [199.232.76.173] (port=35208 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NfFnM-0006qf-Ib for qemu-devel@nongnu.org; Wed, 10 Feb 2010 11:52:08 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1NfFnL-0003xB-NS for qemu-devel@nongnu.org; Wed, 10 Feb 2010 11:52:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:29811) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NfFnL-0003x5-Ab for qemu-devel@nongnu.org; Wed, 10 Feb 2010 11:52:07 -0500 Message-ID: <4B72E430.4070700@redhat.com> Date: Wed, 10 Feb 2010 18:52:00 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling References: <4B728FF9.6010707@lab.ntt.co.jp> <4B72B28E.6010801@redhat.com> <4B72D69D.7050005@codemonkey.ws> <4B72D838.9060603@suse.de> <4B72E051.8090008@codemonkey.ws> <4B72E224.1090901@suse.de> <4B72E2D2.7010701@redhat.com> <4B72E32F.3080205@suse.de> In-Reply-To: <4B72E32F.3080205@suse.de> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Anthony Liguori , "kvm@vger.kernel.org" , mtosatti@redhat.com, OHMURA Kei , "qemu-devel@nongnu.org" On 02/10/2010 06:47 PM, Alexander Graf wrote: >>> Because on PPC, you usually run PPC32 userspace code on a PPC64 kernel. >>> Unlike with x86, there's no real benefit in using 64 bit userspace. >>> >>> >>> >> btw, does 32-bit ppc qemu support large memory guests? It doesn't on >> x86, and I don't remember any hacks to support large memory guests >> elsewhere. >> >> > > It doesn't :-). In fact, the guest we virtualize wouldn't work with > 2 > GB anyways, because that needs an iommu implementation. > Oh, so you may want to revisit the "there's no real benefit in using 64 bit userspace". Seriously, that looks like a big deficiency. What would it take to implement an iommu? I imagine Anthony's latest patches are a first step in that journey. -- error compiling committee.c: too many arguments to function