From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary Date: Wed, 21 Nov 2012 12:33:16 +0200 Message-ID: <20121121103316.GP21208@redhat.com> References: <50AC3AA9.7080004@cn.fujitsu.com> <50AC3B10.3090005@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: "x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Marcelo Tosatti To: Zhang Yanfei Return-path: Content-Disposition: inline In-Reply-To: <50AC3B10.3090005-BthXqXjhjHXQFUHtdCDX3A@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 Wed, Nov 21, 2012 at 10:23:12AM +0800, Zhang Yanfei wrote: > This patch adds an atomic notifier list named crash_notifier_list. > When loading kvm-intel module, a notifier will be registered in > the list to enable vmcss loaded on all cpus to be VMCLEAR'd if > needed. > > 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..5e22b00 100644 > --- a/arch/x86/include/asm/kexec.h > +++ b/arch/x86/include/asm/kexec.h > @@ -163,6 +163,8 @@ struct kimage_arch { > }; > #endif > > +extern struct atomic_notifier_head crash_notifier_list; > + > #endif /* __ASSEMBLY__ */ > > #endif /* _ASM_X86_KEXEC_H */ > diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c > index 13ad899..0f3d5b4 100644 > --- a/arch/x86/kernel/crash.c > +++ b/arch/x86/kernel/crash.c > @@ -16,6 +16,8 @@ > #include > #include > #include > +#include > +#include > > #include > #include > @@ -30,6 +32,19 @@ > > int in_crash_kexec; > > +/* > + * The list is used to VMCLEAR vmcss loaded on all > + * cpus. And when loading kvm_intel module, the > + * vmclear function will be registered in the list. > + */ > +ATOMIC_NOTIFIER_HEAD(crash_notifier_list); > +EXPORT_SYMBOL_GPL(crash_notifier_list); > + > +static inline void cpu_emergency_vmclear_loaded_vmcss(void) > +{ > + atomic_notifier_call_chain(&crash_notifier_list, 0, NULL); > +} > + The notifier list is not VMX specific. It may be used for other purposes, so please use better name or just open code it. ACKs from kexec side are needed. > #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) > > static void kdump_nmi_callback(int cpu, struct pt_regs *regs) > @@ -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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Gleb.