Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753225Ab2KTAdU (ORCPT ); Mon, 19 Nov 2012 19:33:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:26219 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752837Ab2KTAdT (ORCPT ); Mon, 19 Nov 2012 19:33:19 -0500 Date: Mon, 19 Nov 2012 22:32:58 -0200 From: Marcelo Tosatti To: zhangyanfei Cc: "x86@kernel.org" , "kexec@lists.infradead.org" , Avi Kivity , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" Subject: Re: [PATCH v4 0/2] x86: clear vmcss on all cpus when doing kdump if necessary Message-ID: <20121120003258.GA1292@amt.cnet> References: <50A3645F.60302@cn.fujitsu.com> <50A611AA.6030903@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <50A611AA.6030903@cn.fujitsu.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2548 Lines: 62 On Fri, Nov 16, 2012 at 06:12:58PM +0800, zhangyanfei wrote: > Hello Marcelo, > > Any thoughts? I thought a function call was OK, but its better to have all code in vmx.c. Please have an atomic notifier in kexec.c (registered by KVM module via atomic_notifier_chain_register etc). Other than that, which is largely cosmetic, it looks fine. Sorry for not expressing this earlier. > 于 2012年11月14日 17:29, zhangyanfei 写道: > > Currently, kdump just makes all the logical processors leave VMX operation by > > executing VMXOFF instruction, so any VMCSs active on the logical processors may > > be corrupted. But, sometimes, we need the VMCSs to debug guest images contained > > in the host vmcore. To prevent the corruption, we should VMCLEAR the VMCSs before > > executing the VMXOFF instruction. > > > > The patch set provides a way to VMCLEAR vmcss related to guests on all cpus before > > executing the VMXOFF when doing kdump. This is used to ensure the VMCSs in the > > vmcore updated and non-corrupted. > > > > Changelog from v3 to v4: > > 1. add a new percpu variable vmclear_skipped to skip > > vmclear in kdump in some conditions. > > > > Changelog from v2 to v3: > > 1. remove unnecessary conditions in function > > cpu_emergency_clear_loaded_vmcss as Marcelo suggested. > > > > Changelog from v1 to v2: > > 1. remove the sysctl and clear VMCSs unconditionally. > > > > Zhang Yanfei (2): > > x86/kexec: VMCLEAR vmcss on all cpus if necessary > > KVM: set/unset crash_clear_loaded_vmcss and vmclear_skipped in > > kvm_intel module > > > > arch/x86/include/asm/kexec.h | 3 +++ > > arch/x86/kernel/crash.c | 32 ++++++++++++++++++++++++++++++++ > > arch/x86/kvm/vmx.c | 32 ++++++++++++++++++++++++++++++++ > > 3 files changed, 67 insertions(+), 0 deletions(-) > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/