From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: unhandled vm exit: 0x9 Date: Sun, 01 Apr 2007 10:27:37 +0300 Message-ID: <460F5EE9.3020904@qumranet.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Omar Khan Return-path: In-Reply-To: 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 Omar Khan wrote: > hi, > I am trying to run an experimental operating system 'Choices' on kvm and it > is giving me the 'unhandled vm exit: 0x9' error. It runs fine with the -no-kvm > switch though. In an earlier post > (http://article.gmane.org/gmane.comp.emulators.kvm.devel/ > 654/match=unhandled+vm+exit) Avi said that "Exit 9 is a hardware task switch, > which is not supported by vmx" Can someone please elaborate on this. Also any > ideas on how to handle this? > x86 supports a hardware task switch mechanism, almost an OS in hardware. As no modern OS uses it, vmx (as well as svm and x86-64) does not support it. There can be two causes for this: - your OS actually uses the hardware task switch mechanism. in this case, you need to emulate its behavior in kvm. - some bug in kvm caused this to be triggered accidentally. You can determine which case you're seeing by adding a printf() to the qemu task switch emulation and running with -no-kvm. The place to put it is probably switch_tss() in target-i386/helper.c. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV