From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bandan Das Subject: Re: [nVMX] With 3.20.0-0.rc0.git5.1 on L0, booting L2 guest results in L1 *rebooting* Date: Tue, 17 Feb 2015 13:00:36 -0500 Message-ID: References: <20150216204013.GI21838@tesla.redhat.com> <54E2D966.9070706@siemens.com> <20150217112426.GL21838@tesla.redhat.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Jan Kiszka , kvm@vger.kernel.org, dgilbert@redhat.com To: Kashyap Chamarthy Return-path: Received: from mx1.redhat.com ([209.132.183.28]:44984 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751882AbbBQSAm (ORCPT ); Tue, 17 Feb 2015 13:00:42 -0500 In-Reply-To: <20150217112426.GL21838@tesla.redhat.com> (Kashyap Chamarthy's message of "Tue, 17 Feb 2015 12:24:26 +0100") Sender: kvm-owner@vger.kernel.org List-ID: Kashyap Chamarthy writes: .. >> >> Does enable_apicv make a difference? > > Actually, I did perform a test (on Paolo's suggestion on IRC) with > enable_apicv=0 on physical host, and it didn't make any difference: > > $ cat /proc/cmdline > BOOT_IMAGE=/vmlinuz-3.20.0-0.rc0.git5.1.fc23.x86_64 root=/dev/mapper/fedora--server_dell--per910--02-root ro console=ttyS1,115200n81 rd.lvm.lv=fedora-server_dell-per910-02/swap rd.lvm.lv=fedora-server_dell-per910-02/root LANG=en_US.UTF-8 enable_apicv=0 I am not sure if this works ? enable_apicv is a kvm_intel module parameter >> Is this a regression caused by the commit, or do you only see it with >> very recent kvm.git? > > Afraid, I didn't bisect it, but I just wanted to note that the above > specific WARN was introduced in the above commit. You could try an upstream kernel before the recent MSR load/store changes to narrow down the problem. Bandan > I'm sure this Kernel (on L0) does not exhibit the problem: > kernel-3.17.4-301.fc21.x86_64. But, if I had either of these two Kernels > on the physical host, then the said problem manifests (L1 reboots): > 3.19.0-1.fc22 or kernel-3.20.0-0.rc0.git5.1.fc23