From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 1/5] vring: Replace mmap() interface with ioctl() Date: Sun, 15 Jun 2008 08:24:46 -0700 Message-ID: <4855343E.4020808@qumranet.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> <485452E6.4070201@us.ibm.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: Anthony Liguori Return-path: Received: from il.qumranet.com ([212.179.150.194]:30397 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758246AbYFOPYu (ORCPT ); Sun, 15 Jun 2008 11:24:50 -0400 In-Reply-To: <485452E6.4070201@us.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: Anthony Liguori wrote: >> >> 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. But you need to reserve that space to prevent mallocs from going there. How much space do you reserve? > You wouldn't send a packet from/to a PCI IO region so I don't think > that practically speaking that's a problem. If we implement interguest shared memory as a pci device, then it becomes a problem. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.