Re: [Qemu-devel] [PATCH] cpu: smp_wmb before lauching cpus.

[liu ping fan]

On Thu, Jul 5, 2012 at 6:16 PM, Jan Kiszka <address@hidden> wrote:
> On 2012-07-05 12:10, liu ping fan wrote:
>> On Thu, Jul 5, 2012 at 2:46 PM, Jan Kiszka <address@hidden> wrote:
>>> On 2012-07-05 04:18, Liu Ping Fan wrote:
>>>> Vcpu state must be set completely before receiving INIT-IPI,SIPI
>>>>
>>>> Signed-off-by: Liu Ping Fan <address@hidden>
>>>> ---
>>>>  kvm.h |    1 +
>>>>  1 files changed, 1 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/kvm.h b/kvm.h
>>>> index 9c7b0ea..5b3c228 100644
>>>> --- a/kvm.h
>>>> +++ b/kvm.h
>>>> @@ -198,6 +198,7 @@ static inline void 
>>>> cpu_synchronize_post_init(CPUArchState *env)
>>>>  {
>>>>      if (kvm_enabled()) {
>>>>          kvm_cpu_synchronize_post_init(env);
>>>> +        smp_wmb();
>>>>      }
>>>>  }
>>>>
>>>>
>>>
>>> In theory, there should be no vcpu kick-off after this without some
>>> locking operations involved that imply barriers. Did you see real
>>
>> Yeah, but what if it is non-x86?
>
> The locking I'm referring to is arch independent.
>
>>> inconsistencies without this explicit one?
>
> Again: Did you see real issues or is this based on static analysis?
>
Just on  static analysis

Regards,
pingfan
> Jan
>
> --
> Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
> Corporate Competence Center Embedded Linux
>