From mboxrd@z Thu Jan 1 00:00:00 1970 From: TJ Subject: Re: Running KVM on a Laptop Date: Thu, 19 Feb 2009 01:17:15 +0000 Message-ID: <1235006235.11080.98.camel@hephaestion> References: <8CB5B91ADEF0853-D1C-27CD@webmail-md20.sysops.aol.com> <20090218074541.GA7538@apartia.fr> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Louis-David Mitterrand Return-path: Received: from tjworld.net ([67.18.187.6]:40143 "EHLO tjworld.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751510AbZBSBZx (ORCPT ); Wed, 18 Feb 2009 20:25:53 -0500 In-Reply-To: <20090218074541.GA7538@apartia.fr> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, 2009-02-18 at 08:45 +0100, Louis-David Mitterrand wrote: > > Is it not as simple as checking for the svm or vt flags? > > No, one must also check that the bios allows enabling virtualization > support. My sony laptop has the right processor but no bios option. > Check that first! Louis-David, I just noticed your comment in passing and thought I'd let you (and others with a Sony Vaio) know that it is possible to enable the VT option in NVRAM even though the BIOS set-up menu doesn't support it. I did it with this Vaio VGN-FE41Z with T7200 CPU back in mid 2007 and not had to redo it since. I sometimes run several instances of KVM on it. The Phoenix BIOS does support storing in NVRAM and setting the VT-enable bits using MSR 0x3A at boot time. I was hoping to create a Linux tool to make the NVRAM change but due to: * each BIOS version uses a different token number to store the VT-enable BIOS setting * to identify the token number you have to examine the BIOS executable code * currently the only 'safe' way to set the token in NVRAM is to use the DOS symcmos.exe utility (from Phoenix) A one-shot solution proved impractical so it is a case of doing it on a per-BIOS-version basis. If you want to email me off-list with the precise Sony model-number and BIOS revision I should be able to help you enable the VT bit. For some highly technical background see: http://tjworld.net/wiki/Sony/Vaio/FE41Z/HackingBiosNvram