From: Gleb Natapov Subject: Re: [PATCH v9 1/2] x86/kexec: VMCLEAR VMCSs loaded on all cpus if necessary Date: Mon, 3 Dec 2012 15:46:41 +0200 Message-ID: <20121203134641.GA19514@redhat.com> References: <50B43299.9030409@cn.fujitsu.com> <50B432CA.70804@cn.fujitsu.com> <20121127121847.GU25516@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , "kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Zhang Yanfei To: "Eric W. Biederman" Return-path: Content-Disposition: inline In-Reply-To: <20121127121847.GU25516-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kexec-bounces-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Errors-To: kexec-bounces+glkk-kexec=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: kvm.vger.kernel.org On Tue, Nov 27, 2012 at 02:18:47PM +0200, Gleb Natapov wrote: > Eric, can you ACK it? > Eric, ping. > On Tue, Nov 27, 2012 at 11:26:02AM +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: Zhang Yanfei > > --- > > arch/x86/include/asm/kexec.h | 2 ++ > > arch/x86/kernel/crash.c | 25 +++++++++++++++++++++++++ > > 2 files changed, 27 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..4a2a12f 100644 > > --- a/arch/x86/kernel/crash.c > > +++ b/arch/x86/kernel/crash.c > > @@ -16,6 +16,7 @@ > > #include > > #include > > #include > > +#include > > > > #include > > #include > > @@ -29,6 +30,20 @@ > > #include > > > > 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. > > + */ > > +void (*crash_vmclear_loaded_vmcss)(void) = NULL; > > +EXPORT_SYMBOL_GPL(crash_vmclear_loaded_vmcss); > > + > > +static inline void cpu_emergency_vmclear_loaded_vmcss(void) > > +{ > > + if (crash_vmclear_loaded_vmcss) > > + crash_vmclear_loaded_vmcss(); > > +} > > > > #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) > > > > @@ -46,6 +61,11 @@ 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_vmclear_loaded_vmcss(); > > + > > /* Disable VMX or SVM if needed. > > * > > * We need to disable virtualization on all CPUs. > > @@ -88,6 +108,11 @@ void native_machine_crash_shutdown(struct pt_regs *regs) > > > > kdump_nmi_shootdown_cpus(); > > > > + /* > > + * VMCLEAR VMCSs loaded on this cpu if needed. > > + */ > > + cpu_emergency_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 > > -- > Gleb. > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Gleb.