From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61639C3A5A6 for ; Tue, 27 Aug 2019 22:27:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38DE6206BF for ; Tue, 27 Aug 2019 22:27:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726408AbfH0W1P (ORCPT ); Tue, 27 Aug 2019 18:27:15 -0400 Received: from mga07.intel.com ([134.134.136.100]:59462 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725976AbfH0W1P (ORCPT ); Tue, 27 Aug 2019 18:27:15 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Aug 2019 15:27:14 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,438,1559545200"; d="scan'208";a="264441178" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.41]) by orsmga001.jf.intel.com with ESMTP; 27 Aug 2019 15:27:14 -0700 Date: Tue, 27 Aug 2019 15:27:14 -0700 From: Sean Christopherson To: Paolo Bonzini , Radim =?utf-8?B?S3LEjW3DocWZ?= Cc: kvm@vger.kernel.org Subject: Re: [PATCH v3 0/2] KVM: nVMX: add tracepoints for nested VM-Enter failures Message-ID: <20190827222714.GL27459@linux.intel.com> References: <20190711155830.15178-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190711155830.15178-1-sean.j.christopherson@intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Ping. On Thu, Jul 11, 2019 at 08:58:28AM -0700, Sean Christopherson wrote: > Debugging VM-Enter failures has been the bane of my existence for years. > Seeing KVM's VMCS dump format pop up on a console triggers a Pavlovian > response of swear words and sighs. As KVM's coverage of VM-Enter checks > improve, so too do the odds of being able to triage/debug a KVM (or any > other hypervisor) bug by running the bad KVM build as an L1 guest. > > Improve support for using KVM to debug a buggy VMM by adding tracepoints > to capture the basic gist of a VM-Enter failure so that extracting said > information from KVM doesn't require attaching a debugger or modifying > L0 KVM to manually log failures. > > The captured information is by no means complete or perfect, e.g. I'd > love to capture *exactly* why a consistency check failed, but logging > that level of detail would require invasive code changes and might even > act as a deterrent to adding more checks in KVM. > > v3: Fix a minor snafu in the v2 rebase, and re-rebase to kvm/next > (a45ff5994c9c, "Merge tag 'kvm-arm-for-5.3'...") > > v2: Rebase to kvm/queue. > > Sean Christopherson (2): > KVM: nVMX: add tracepoint for failed nested VM-Enter > KVM: nVMX: trace nested VM-Enter failures detected by H/W > > arch/x86/include/asm/vmx.h | 14 ++ > arch/x86/kvm/trace.h | 22 +++ > arch/x86/kvm/vmx/nested.c | 269 ++++++++++++++++++++----------------- > arch/x86/kvm/x86.c | 1 + > 4 files changed, 179 insertions(+), 127 deletions(-) > > -- > 2.22.0 >