From mboxrd@z Thu Jan 1 00:00:00 1970 From: Valentine Sinitsyn Subject: Nested paging in nested SVM setup Date: Wed, 18 Jun 2014 17:36:36 +0600 Message-ID: <53A179C4.9060203@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from mail-lb0-f180.google.com ([209.85.217.180]:56530 "EHLO mail-lb0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933954AbaFRLgl (ORCPT ); Wed, 18 Jun 2014 07:36:41 -0400 Received: by mail-lb0-f180.google.com with SMTP id w7so414321lbi.25 for ; Wed, 18 Jun 2014 04:36:39 -0700 (PDT) Received: from [192.168.99.5] (167.251-106-89.FTTH.rus-com.net. [89.106.251.167]) by mx.google.com with ESMTPSA id vq4sm1402784lbb.14.2014.06.18.04.36.37 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 18 Jun 2014 04:36:38 -0700 (PDT) Sender: kvm-owner@vger.kernel.org List-ID: Hi all, I'm using a KVM/Qemu nested SVM setup to debug another hypervisor (Jailhouse) I contribute to. IOW, the scheme is: AMD64 Linux host running [paravirtualized] AMD64 Linux guest (the same kernel as the host) running Jailhouse. Jailhouse, in turn, uses Nested Paging to virtualize xAPIC: APIC page (0xfee00000, no APIC remapping) is mapped read-only into Jailhouse's guests. This of course implies that APIC page appears to Jailhouse guests as uncacheable (UC). Is it achievable in the setup I described, or do I need to run my code on a real hardware to make the APIC page accesses in Jailhouse guests uncacheable? Thanks in advance. -- Best regards, Valentine Sinitsyn