From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932787Ab2LFPk5 (ORCPT ); Thu, 6 Dec 2012 10:40:57 -0500 Received: from mail-da0-f46.google.com ([209.85.210.46]:44757 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932229Ab2LFPk4 (ORCPT ); Thu, 6 Dec 2012 10:40:56 -0500 Message-ID: <50C0BC7F.8030302@gmail.com> Date: Thu, 06 Dec 2012 23:40:47 +0800 From: Zhang Yanfei User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.5) Gecko/20120607 Thunderbird/10.0.5 MIME-Version: 1.0 To: Marcelo Tosatti , Gleb Natapov , "Eric W. Biederman" CC: kexec@lists.infradead.org, "kvm@vger.kernel.org" , linux-kernel@vger.kernel.org Subject: [PATCH v11 1/2] x86/kexec: VMCLEAR VMCSs loaded on all cpus if necessary References: <50C0BB90.1080804@gmail.com> In-Reply-To: <50C0BB90.1080804@gmail.com> Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zhang Yanfei This patch 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. Signed-off-by: Zhang Yanfei Acked-by: Eric W. Biederman --- arch/x86/include/asm/kexec.h | 2 ++ arch/x86/kernel/crash.c | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index 317ff17..28feeba 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -163,6 +163,8 @@ struct kimage_arch { }; #endif +extern void (*crash_vmclear_loaded_vmcss)(void); + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_KEXEC_H */ diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 13ad899..b914b7f 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 all VMCSs loaded on the + * processor. And when loading kvm_intel module, the + * callback function pointer will be assigned. + * + * protected by rcu. + */ +void (*crash_vmclear_loaded_vmcss)(void) = NULL; +EXPORT_SYMBOL_GPL(crash_vmclear_loaded_vmcss); + +static inline void cpu_crash_vmclear_loaded_vmcss(void) +{ + void (*do_vmclear_operation)(void) = NULL; + + rcu_read_lock(); + do_vmclear_operation = rcu_dereference(crash_vmclear_loaded_vmcss); + if (do_vmclear_operation) + do_vmclear_operation(); + rcu_read_unlock(); +} + #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_crash_vmclear_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_crash_vmclear_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. -- 1.7.1