From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhang Yanfei Subject: [PATCH v10 1/2] x86/kexec: VMCLEAR VMCSs loaded on all cpus if necessary Date: Wed, 05 Dec 2012 16:03:12 +0800 Message-ID: <50BEFFC0.6030709@cn.fujitsu.com> References: <50BEFEBA.6070602@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: "kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" To: Marcelo Tosatti , Gleb Natapov , "Eric W. Biederman" Return-path: In-Reply-To: <50BEFEBA.6070602-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 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 | 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_opertaion(); + 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