From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: Does KVM use one EPT table per Guest CR3? Date: Tue, 07 Dec 2010 15:57:20 -0600 Message-ID: <4CFEADC0.9030002@codemonkey.ws> References: <562744ED4DABB345A26E01CB5D34F5103192CFFE@BL2PRD0103MB033.prod.exchangelabs.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" To: Lok Kwong Yan Return-path: Received: from mail-qy0-f174.google.com ([209.85.216.174]:60735 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753206Ab0LGV50 (ORCPT ); Tue, 7 Dec 2010 16:57:26 -0500 Received: by qyk11 with SMTP id 11so5518466qyk.19 for ; Tue, 07 Dec 2010 13:57:26 -0800 (PST) In-Reply-To: <562744ED4DABB345A26E01CB5D34F5103192CFFE@BL2PRD0103MB033.prod.exchangelabs.com> Sender: kvm-owner@vger.kernel.org List-ID: On 12/07/2010 03:47 PM, Lok Kwong Yan wrote: > After some testing and digging around the 2.6.32-26 Kernel, Ubuntu port, , it seems to me that KVM creates a separate EPT table for each separate guest CR3 value. So, if there are 100 guest processes, there are essentially 100 EPT tables. Is this correct? No, it's not correct. Regards, Anthony Liguori > If so, can someone please tell me where these tables are actually being created? Is this design decision a historical artifact from how QEMU/KVM (without EPT/NPT) created multiple shadow page tables so that each guest/virtual CR3 value has a corresponding real CR3 value so that memory based separation for the guest is enforced? > > Thanks!-- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >