From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [BUG] GPF on hardware breakpoints (preempt_notifier) Date: Sun, 09 Sep 2007 15:43:39 -0500 Message-ID: <46E45AFB.9090406@codemonkey.ws> References: <20070909171422.GA13345@dreamland.darkstar.lan> <46E42D99.6030905@qumranet.com> <68676e00709091145p34fad472u5cf3e1d939754367@mail.gmail.com> <46E4542F.8040705@codemonkey.ws> <68676e00709091323r23c59dch3f75177616b3f7f5@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-TtF/mJH4Jtrk1uMJSBkQmQ@public.gmane.org, Avi Kivity To: Luca Return-path: In-Reply-To: <68676e00709091323r23c59dch3f75177616b3f7f5-JsoAwUIsXosN+BqQ9rBEUg@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 Luca wrote: > On 9/9/07, Anthony Liguori wrote: > >> Luca wrote: >> >>> On 9/9/07, Avi Kivity wrote: >>> >>> >>>> Luca Tettamanti wrote: >>>> >>>> >>>>> Hi, >>>>> while debugging a program with GDB I got a GPF which seems related to >>>>> KVM. Note that I was *not* using the debugger inside the guest nor on >>>>> the virtual machine. The target was an unrelated userspace program. >>>>> >>>>> >>>>> >>>> Yes, kvm is dirtily misappropriating the debug registers on older >>>> kernels. >>>> >>>> >>> I'm runninng the current Linus' git tree, shall I test kvm.git? >>> >>> >> Do you have CONFIG_PREEMPT_NOTIFIERS enabled? >> > > No, it's disabled. > If you enable it, you probably won't see this problem. KVM emulates PREEMPT_NOTIFIERS using debug registers. Regards, Anthony Liguori > Luca > > ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/