Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757689Ab2JaBdQ (ORCPT ); Tue, 30 Oct 2012 21:33:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30556 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756075Ab2JaBdG (ORCPT ); Tue, 30 Oct 2012 21:33:06 -0400 Date: Tue, 30 Oct 2012 22:18:22 -0200 From: Marcelo Tosatti To: Zhang Yanfei Cc: x86@kernel.org, kexec@lists.infradead.org, Avi Kivity , linux-kernel@vger.kernel.org, "kvm@vger.kernel.org" Subject: Re: [PATCH 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary Message-ID: <20121031001822.GA21986@amt.cnet> References: <5080E813.7030302@cn.fujitsu.com> <5080E8BF.3020506@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5080E8BF.3020506@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: 3184 Lines: 104 On Fri, Oct 19, 2012 at 01:44:31PM +0800, Zhang Yanfei wrote: > 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: zhangyanfei > --- > arch/x86/include/asm/kexec.h | 2 ++ > arch/x86/kernel/crash.c | 27 +++++++++++++++++++++++++++ > 2 files changed, 29 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h > index 317ff17..fc05440 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_clear_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..7289976 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 +31,22 @@ > > 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); > + > +static void cpu_emergency_clear_loaded_vmcss(void) > +{ > + if (crash_clear_loaded_vmcss && > + cpu_has_vmx() && cpu_vmx_enabled()) { > + crash_clear_loaded_vmcss(); > + } > +} > + Are all this checks necessary? if (crash_clear_loaded_vmcss) crash_clear_loaded_vmcss(); Should be enough ? (callback only set if kvm-vmx module loaded). > #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) > > static void kdump_nmi_callback(int cpu, struct pt_regs *regs) > @@ -46,6 +63,11 @@ 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 +110,11 @@ 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. > -- > 1.7.1 > > -- > 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/