From patchwork Wed Nov 14 09:31:15 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yanfei Zhang X-Patchwork-Id: 1740111 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 7122DDF264 for ; Wed, 14 Nov 2012 09:33:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932785Ab2KNJc7 (ORCPT ); Wed, 14 Nov 2012 04:32:59 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:62747 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754466Ab2KNJc5 (ORCPT ); Wed, 14 Nov 2012 04:32:57 -0500 X-IronPort-AV: E=Sophos;i="4.83,249,1352044800"; d="scan'208";a="6195908" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 14 Nov 2012 17:31:16 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id qAE9Wt9N003803; Wed, 14 Nov 2012 17:32:55 +0800 Received: from [10.167.226.121] ([10.167.226.121]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2012111417325064-1149066 ; Wed, 14 Nov 2012 17:32:50 +0800 Message-ID: <50A364E3.2090608@cn.fujitsu.com> Date: Wed, 14 Nov 2012 17:31:15 +0800 From: zhangyanfei User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.8) Gecko/20121012 Thunderbird/10.0.8 MIME-Version: 1.0 To: "x86@kernel.org" , "kexec@lists.infradead.org" , Avi Kivity , Marcelo Tosatti CC: "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" Subject: [PATCH v4 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary References: <50A3645F.60302@cn.fujitsu.com> In-Reply-To: <50A3645F.60302@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/11/14 17:32:50, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/11/14 17:32:51, Serialize complete at 2012/11/14 17:32:51 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org crash_clear_loaded_vmcss is added to VMCLEAR vmcss loaded on all cpus. And when loading kvm_intel module, the function pointer will be made valid. The percpu variable vmclear_skipped is added to flag the case that if loaded_vmcss_on_cpu list is being modified while the machine crashes and doing kdump, the vmclear here can be skipped. Signed-off-by: Zhang Yanfei --- arch/x86/include/asm/kexec.h | 3 +++ arch/x86/kernel/crash.c | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 35 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index 317ff17..d892211 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -163,6 +163,9 @@ struct kimage_arch { }; #endif +extern void (*crash_clear_loaded_vmcss)(void); +DECLARE_PER_CPU(int, vmclear_skipped); + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */ diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 13ad899..b9f264e 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -30,6 +31,27 @@ int in_crash_kexec; +/* + * This is used to VMCLEAR vmcss loaded on all + * cpus. And when loading kvm_intel module, the + * function pointer will be made valid. + */ +void (*crash_clear_loaded_vmcss)(void) = NULL; +EXPORT_SYMBOL_GPL(crash_clear_loaded_vmcss); + +DEFINE_PER_CPU(int, vmclear_skipped) = 1; +EXPORT_SYMBOL_GPL(vmclear_skipped); + +static void cpu_emergency_clear_loaded_vmcss(void) +{ + int cpu = raw_smp_processor_id(); + int skipped; + + skipped = per_cpu(vmclear_skipped, cpu); + if (!skipped && crash_clear_loaded_vmcss) + crash_clear_loaded_vmcss(); +} + #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) static void kdump_nmi_callback(int cpu, struct pt_regs *regs) @@ -46,6 +68,11 @@ static void kdump_nmi_callback(int cpu, struct pt_regs *regs) #endif crash_save_cpu(regs, cpu); + /* + * VMCLEAR vmcss loaded on all cpus if needed. + */ + cpu_emergency_clear_loaded_vmcss(); + /* Disable VMX or SVM if needed. * * We need to disable virtualization on all CPUs. @@ -88,6 +115,11 @@ void native_machine_crash_shutdown(struct pt_regs *regs) kdump_nmi_shootdown_cpus(); + /* + * VMCLEAR vmcss loaded on this cpu if needed. + */ + cpu_emergency_clear_loaded_vmcss(); + /* Booting kdump kernel with VMX or SVM enabled won't work, * because (among other limitations) we can't disable paging * with the virt flags.