From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] KVM: VMX: Move private memory slot position Date: Thu, 16 Oct 2008 10:26:07 +0200 Message-ID: <48F6FA9F.3080408@redhat.com> References: <200809041130.20249.sheng.yang@intel.com> <48CB4935.5090505@qumranet.com> <48CB7FFF.1020306@qumranet.com> <200810131717.26020.sheng.yang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: "Yang, Sheng" Return-path: Received: from mx2.redhat.com ([66.187.237.31]:58410 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751295AbYJPI0L (ORCPT ); Thu, 16 Oct 2008 04:26:11 -0400 In-Reply-To: <200810131717.26020.sheng.yang@intel.com> Sender: kvm-owner@vger.kernel.org List-ID: Yang, Sheng wrote: > I've found the reason... It's because that kvm_mmu_page->slot_bitmap is > unsigned long, and if use KVM_MEMORY_SLOTS + xxx, it would beyond 32 in pae, > then memory corrupted. > > But reduce supported memory slot number to 28 or extend slot_bitmap, or other > methods? Slot_bitmap have bitops, so keep unsigned long would be better... > Now reduce supported memory slot number seems reasonable to me. > > We could change it to DECLARE_BITMAP, and thus support >= 32 slots even on i386. But I agree that 28 slots would be sufficient. > (I also want to have this fix into 2.6.28, for some device would easily > overlapped with current private memory slot) > I've been thinking that we can get rid of internal slots, by placing the TSS, real mode identity map, and APIC access page in the bios. Of course we would need a new ioctl to let the kernel know where the scratch memory is located and how much of it is available. -- error compiling committee.c: too many arguments to function