From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Does KVM use one EPT table per Guest CR3? Date: Sun, 12 Dec 2010 12:47:11 +0200 Message-ID: <4D04A82F.4020808@redhat.com> References: <562744ED4DABB345A26E01CB5D34F5103192CFFE@BL2PRD0103MB033.prod.exchangelabs.com>,<4CFEADC0.9030002@codemonkey.ws> <562744ED4DABB345A26E01CB5D34F51031930BF9@BL2PRD0103MB033.prod.exchangelabs.com>,<4CFEB126.6070409@codemonkey.ws> <562744ED4DABB345A26E01CB5D34F51031930CCE@BL2PRD0103MB033.prod.exchangelabs.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Anthony Liguori , "kvm@vger.kernel.org" To: Lok Kwong Yan Return-path: Received: from mx1.redhat.com ([209.132.183.28]:63412 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752270Ab0LLKrZ (ORCPT ); Sun, 12 Dec 2010 05:47:25 -0500 In-Reply-To: <562744ED4DABB345A26E01CB5D34F51031930CCE@BL2PRD0103MB033.prod.exchangelabs.com> Sender: kvm-owner@vger.kernel.org List-ID: On 12/10/2010 09:44 AM, Lok Kwong Yan wrote: > Thanks again. > > I understand that the table can change over time, but it doesn't explain why the top-most table gets zapped and seemingly recreated with a different page frame (and thus the different EPTP values) so frequently. Why isn't the table being updated instead of being destroyed and then recreated? Which piece of the puzzle and I missing? When the physical memory map changes the EPT tables are zapped. This happens when PCI BARs are remapped, or when VGA remaps the framebuffer windows at 0xa0000-0xc0000. Both of these happen during boot. Do you see zaps happening after boot is complete? -- error compiling committee.c: too many arguments to function