From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH v2] KVM: nVMX: Fix setting of CR0 and CR4 in guest mode Date: Wed, 6 Mar 2013 21:33:52 -0300 Message-ID: <20130307003352.GA29343@amt.cnet> References: <5134F8AD.8030607@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Gleb Natapov , kvm , "Nadav Har'El" To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:46560 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757658Ab3CGAhM (ORCPT ); Wed, 6 Mar 2013 19:37:12 -0500 Content-Disposition: inline In-Reply-To: <5134F8AD.8030607@web.de> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, Mar 04, 2013 at 08:40:29PM +0100, Jan Kiszka wrote: > The logic for calculating the value with which we call kvm_set_cr0/4 was > broken (will definitely be visible with nested unrestricted guest mode > support). Also, we performed the check regarding CR0_ALWAYSON too early > when in guest mode. > > What really needs to be done on both CR0 and CR4 is to mask out L1-owned > bits and merge them in from GUEST_CR0/4. In contrast, arch.cr0/4 and > arch.cr0/4_guest_owned_bits contain the mangled L0+L1 state and, thus, > are not suited as input. > > For both CRs, we can then apply the check against VMXON_CRx_ALWAYSON and > refuse the update if it fails. To be fully consistent, we implement this > check now also for CR4. > > Finally, we have to set the shadow to the value L2 wanted to write > originally. > > Signed-off-by: Jan Kiszka Applied, thanks.