From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] KVM: is_long_mode should check for EFER_LMA Date: Sun, 04 Nov 2007 09:17:32 +0200 Message-ID: <472D720C.2080307@qumranet.com> References: <200711030242.02001.amit.shah@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Amit Shah Return-path: In-Reply-To: <200711030242.02001.amit.shah-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Amit Shah wrote: > >From bfed574c93b36a19e2976ddcaae7939dd6c6fc41 Mon Sep 17 00:00:00 2001 > From: Amit Shah > Date: Sat, 3 Nov 2007 02:38:00 +0530 > Subject: [PATCH] KVM: is_long_mode should check for EFER_LMA > > is_long_mode currently checks the LongModeEnable bit in > EFER instead of the LongModeActive bit. This should work > for most cases, but for some broken implementations that > set the LME bit before enabling PAE in CR4 to enter long > mode. > > This is noticed on a solaris guest on an AMD host (but might > not be specific to AMD). > > Patch looks good and obviously correct to me. But: - why do you say 'broken implementations'? do you mean 'broken guests'? I think that behavior is as specified. - what guest action triggered the failure? (e.g. mov cr4, or what?) - please supply a patch to the testsuite that adds a regression test for this issue. -- Any sufficiently difficult bug is indistinguishable from a feature. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/