From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH 1/5] vring: Replace mmap() interface with ioctl() Date: Sat, 14 Jun 2008 18:23:18 -0500 Message-ID: <485452E6.4070201@us.ibm.com> References: <1213365481-23460-1-git-send-email-markmc@redhat.com> <1213365481-23460-2-git-send-email-markmc@redhat.com> <200806141902.54119.rusty@rustcorp.com.au> <4853D3CB.4090709@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Rusty Russell , Mark McLoughlin , kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from e3.ny.us.ibm.com ([32.97.182.143]:41456 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754994AbYFNXXm (ORCPT ); Sat, 14 Jun 2008 19:23:42 -0400 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e3.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m5ENNdg1018550 for ; Sat, 14 Jun 2008 19:23:39 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v9.0) with ESMTP id m5ENNXc9225432 for ; Sat, 14 Jun 2008 19:23:33 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m5ENNXOO020155 for ; Sat, 14 Jun 2008 19:23:33 -0400 In-Reply-To: <4853D3CB.4090709@qumranet.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > Rusty Russell wrote: >> BTW, including base and limit makes sense. I didn't do this to start >> since Avi doesn't want to guarentee kvm's guest mapping linear (of >> course he's only doing this so he can fix it later). >> > > And also, because memory hotplug and 64-bit PCI BARs require reserving > an infinite virtual address space range. Not to mention that someone > needs to update the dirty bitmap in case we're live migrating. You can certainly hotplug to the next RAM address so it doesn't require infinite space. You wouldn't send a packet from/to a PCI IO region so I don't think that practically speaking that's a problem. But the base/limit thing is a bit of a hack. I don't think the userspace translation is going to be a problem. Regards, Anthony Liguori