[PATCH v5 1/2] x86/kexec: VMCLEAR vmcss on all cpus if necessary

[Zhang Yanfei]

于 2012年11月22日 14:34, Gleb Natapov 写道:
> On Thu, Nov 22, 2012 at 08:59:15AM +0800, Zhang Yanfei wrote:
>> 于 2012年11月21日 18:33, Gleb Natapov 写道:
>>> 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 <zhangyanfei at cn.fujitsu.com>
>>>> ---
>>>>  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 <linux/delay.h>
>>>>  #include <linux/elf.h>
>>>>  #include <linux/elfcore.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/notifier.h>
>>>>  
>>>>  #include <asm/processor.h>
>>>>  #include <asm/hardirq.h>
>>>> @@ -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.
>>
>> OK, thanks. crash_notifier_list --> vmclear_notifier_list?
> It is even worse. You are adding general infrastructure here, not
> related to KVM at all. Choose neutral names, drop all comments about
> VMCLEAR.

Ah, I think I misunderstood what you mean before.
OK, I know what you mean now: make crash_notifier_list unchanged
and remove the comments related to VMX
and open code the atomic_notifier_call_chain function.

Thanks