From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerone Young Subject: Re: Re: [PATCH] supporting non-NX/XD capable processors on x86_64 xenlinux Date: Thu, 18 Aug 2005 11:24:52 -0500 Message-ID: <1124382292.7723.11.camel@thinkpad> References: <7F740D512C7C1046AB53446D3720017304E98EE3@scsmsx402.amr.corp.intel.com> <8cdff1e4320b05b5c89260ad99f23898@cl.cam.ac.uk> <1124381142.7723.9.camel@thinkpad> <20050818161834.GB6977@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20050818161834.GB6977@wotan.suse.de> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Andi Kleen Cc: xen-devel@lists.xensource.com, Jerone Young List-Id: xen-devel@lists.xenproject.org On Thu, 2005-08-18 at 18:18 +0200, Andi Kleen wrote: > On Thu, Aug 18, 2005 at 11:05:42AM -0500, Jerone Young wrote: > > On Thu, 2005-08-18 at 17:51 +0200, Andi Kleen wrote: > > > Keir Fraser writes: > > > > > > > > By the way -- from what I've seen of this NX/XD discussion so far, it > > > > sounds like even if CPUID says that NX/XD is supported, and you set > > > > the EFER.NXE bit, the BIOS can still cause this to be ignored! Is this > > > > true and, if so, what will happen if you try to use NX/XD anyway? > > > > i.e., will the bit be ignored, or will its use cause a page fault? > > > > > > I don't think that can happen. When NX is disabled or not there it > > > doesn't appear in CPUID. > > > > Ah but it does: hehe... I didn't realize I left that statement in there...I just wanted to post to the list to confirm with an example. Don't worry Andi ... your still the x86-64 god in my book! > > Your example confirms what I said. > > -Andi > -- Jerone Young IBM Linux Technology Center jyoung5@us.ibm.com 512-838-1157 (T/L: 678-1157)