From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MjT9B-0003EC-QN for qemu-devel@nongnu.org; Fri, 04 Sep 2009 03:23:49 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MjT97-0003AS-BM for qemu-devel@nongnu.org; Fri, 04 Sep 2009 03:23:49 -0400 Received: from [199.232.76.173] (port=50525 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MjT97-0003AO-8J for qemu-devel@nongnu.org; Fri, 04 Sep 2009 03:23:45 -0400 Received: from mx20.gnu.org ([199.232.41.8]:23251) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MjT96-0008Ef-M8 for qemu-devel@nongnu.org; Fri, 04 Sep 2009 03:23:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MjT95-0008IW-Uy for qemu-devel@nongnu.org; Fri, 04 Sep 2009 03:23:44 -0400 From: Mark McLoughlin In-Reply-To: <5d6222a80909031518h2bf804fbk1f7a52424d3e8649@mail.gmail.com> References: <1252008114.3084.136.camel@blaa> <5d6222a80909031518h2bf804fbk1f7a52424d3e8649@mail.gmail.com> Content-Type: text/plain Date: Fri, 04 Sep 2009 08:22:41 +0100 Message-Id: <1252048961.3144.8.camel@blaa> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH] qemu-kvm: fix segfault when running kvm without /dev/kvm, falling back to non-accelerated mode Reply-To: Mark McLoughlin List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Glauber Costa Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, Dustin Kirkland On Thu, 2009-09-03 at 19:18 -0300, Glauber Costa wrote: > On Thu, Sep 3, 2009 at 6:48 PM, Dustin Kirkland wrote: > > On Thu, Sep 3, 2009 at 3:01 PM, Mark McLoughlin wrote: > >> On Thu, 2009-09-03 at 12:31 -0500, Dustin Kirkland wrote: > >>> qemu-kvm: fix segfault when running kvm without /dev/kvm, falling back > >>> to non-accelerated mode > >>> > >>> We're seeing segfaults on systems without access to /dev/kvm. It > >>> looks like the global kvm_allowed is being set just a little too late > >>> in vl.c. This patch moves the kvm initialization a bit higher in the > >>> vl.c main, just after options processing, and solves the segfaults. > >>> We're carrying this patch in Ubuntu 9.10 Alpha. Please apply > >>> upstream, or advise if and why this might not be the optimal solution. > >> > >> Ah discussion about an alternative fix for this fizzled out recently: > >> > >> http://www.mail-archive.com/kvm@vger.kernel.org/msg19890.html > > > > Ah, thanks Mark. In that thread, I found Daniel's suggestion the most > > reasonable, and user-friendly: > > > > On Mon, Jul 27, 2009 at 1:44 PM, Daniel P. Berrange wrote: > >> Well, we could go for logic like: > >> > >> * No arg given => try kvm, try kqemu, try tcg > >> * --accelmode arg given => try $arg, and fail if unavailable > >> > >> then libvirt would simply always supply --accelmode for all VMs, > >> while people running qemu manually would get best available > I sent some patches to do that, but they were incomplete, and I was > preempted by something else. > If you want, you can wait for my cycles to come back, or pick from where I left In the meantime, can we commit to stable-0.11 either Dustin's fix or this: http://git.et.redhat.com/?p=qemu-fedora.git;a=commitdiff;h=aa1620047b Cheers, Mark.