From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: Nested paging in nested SVM setup Date: Thu, 21 Aug 2014 13:06:44 +0200 Message-ID: <53F5D2C4.7060403@siemens.com> References: <53A179C4.9060203@gmail.com> <53A18A6D.2050407@siemens.com> <53F44440.6070408@gmail.com> <53F44645.2000708@redhat.com> <53F45036.1070309@gmail.com> <53F45832.5080708@redhat.com> <53F59192.3070500@gmail.com> <53F5B250.3000206@gmail.com> <53F5D251.60009@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit To: Paolo Bonzini , Valentine Sinitsyn , kvm@vger.kernel.org Return-path: Received: from thoth.sbs.de ([192.35.17.2]:52401 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753849AbaHULGw (ORCPT ); Thu, 21 Aug 2014 07:06:52 -0400 In-Reply-To: <53F5D251.60009@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2014-08-21 13:04, Paolo Bonzini wrote: > Il 21/08/2014 10:48, Valentine Sinitsyn ha scritto: >> So I'm returning to my original question: is this an intended behavior >> of KVM that APIC access on nested page tables level are not trapped, or >> is this a bug? > > I think it's just a bug. Nobody thought that you'd let L2 access L1's > APIC via NPT. Let me think of how to fix it. Do you think it would only affect the APIC, or could it cause troubles with other pass-through devices as well (some PCI BAR e.g.)? Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux