From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sander van Leeuwen Subject: KVM & VMX root mode Date: Fri, 31 Aug 2007 15:02:14 +0200 Message-ID: <46D81156.8050100@innotek.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Return-path: 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 Hi, We have had several reports of users saying our product VirtualBox crashes their (Linux) host. It turned out that KVM is responsible, because it leaves the CPU in VMX root mode. Doing this changes the way the cpu operates: updates to reserved bits in control registers cause general protection faults. We hit such cases on two occasions; clearing the X86_CR4_VMXE bit in CR4 and turning off paging. I have added a workaround to detect VMX root mode, simply refuse to run and recommend that the user disables KVM. I would however appreciate if you could fix KVM instead. -- Kind regards / mit freundlichen Gruessen / Met vriendelijke groet Sander van Leeuwen innoTek GmbH http://www.innotek.de Germany ------------------------------------------------------------------------- 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/