From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nadav Har'El" Subject: Re: [PATCH 12/30] nVMX: Implement VMPTRLD Date: Mon, 16 May 2011 22:09:48 +0300 Message-ID: <20110516190948.GC12015@fermat.math.technion.ac.il> References: <1304842511-nyh@il.ibm.com> <201105080821.p488LM55018138@rice.haifa.ibm.com> <20110516143421.GB3814@amt.cnet> <20110516185816.GB12015@fermat.math.technion.ac.il> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, gleb@redhat.com, avi@redhat.com To: Marcelo Tosatti Return-path: Received: from mailgw12.technion.ac.il ([132.68.225.12]:61740 "EHLO mailgw12.technion.ac.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752098Ab1EPTJv (ORCPT ); Mon, 16 May 2011 15:09:51 -0400 Content-Disposition: inline In-Reply-To: <20110516185816.GB12015@fermat.math.technion.ac.il> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, May 16, 2011, Nadav Har'El wrote about "Re: [PATCH 12/30] nVMX: Implement VMPTRLD": > But now that I think about it, there does appear to be a problem in > nested_vmx_run(): This is where we should have verified that there is a > current VMCS - i.e., that VMPTRLD was previously used! And it seems I forgot > testing this... :( I'll need to add such a test - not as a BUG_ON but as > a real test that causes the VMLAUNCH instruction to fail (I have to look at > the spec to see exactly how) if VMPTRLD hadn't been previously done. Oh, and there appears to be a similar problem with VMWRITE/VMREAD - it also can be called before VMPTRLD was ever called, and cause us to dereference stupid pointers. Thanks for spotting this. Nadav. -- Nadav Har'El | Monday, May 16 2011, 13 Iyyar 5771 nyh@math.technion.ac.il |----------------------------------------- Phone +972-523-790466, ICQ 13349191 |If I were two-faced, would I be wearing http://nadav.harel.org.il |this one?.... Abraham Lincoln