Re: use tasklet to handle init/sipi?

[Keir Fraser <keir.xen@gmail.com>]

On 28/03/2013 06:39, "Qiu, Shuang" <shuang.qiu@intel.com> wrote:

> Hi Keir,
> 
> Thank you for the patch.
> 
> We've patched the enclosed file on xen-unstable and tested on qemu.git and
> qemu-upstream-unstable.git as backends.
> In both cases, your patch works.

Thanks for the testing! I have now committed my patch.

 -- Keir

> Best regards!
> Shuang
> 
> 
> -----Original Message-----
> From: Keir Fraser [mailto:keir.xen@gmail.com]
> Sent: Tuesday, March 26, 2013 4:02 PM
> To: Zhang, Yang Z; xen-devel@lists.xen.org
> Cc: Jan Beulich; Zhang, Xiantao; Qiu, Shuang
> Subject: Re: use tasklet to handle init/sipi?
> 
> On 26/03/2013 07:55, "Keir Fraser" <keir.xen@gmail.com> wrote:
> 
>> On 26/03/2013 07:41, "Zhang, Yang Z" <yang.z.zhang@intel.com> wrote:
>> 
>>> Keir Fraser wrote on 2013-03-26:
>>>> On 26/03/2013 07:17, "Zhang, Yang Z" <yang.z.zhang@intel.com> wrote:
>>>> 
>>>>>>> Oh, I see. Well I think it is fine to have
>>>>>>> vlapic_schedule_init_sipi_tasklet() return X86EMUL_OKAY rather
>>>>>>> than X86EMUL_RETRY. We used to need to return RETRY, but the code
>>>>>>> got simplified and now it is actually unnecessary.
>>>>>>> 
>>>>>>> That should make your patch a lot simpler eh? ;)
>>>>>> 
>>>>>> Given that you ignore the return code on the apicv call path, is
>>>>>> there currently a bug at all for you? Seems what is there already
>>>>>> must work for you?
>>>>> It do cause bug after we change to use seabios. For seabios, it
>>>>> will send INIT/SIPI to all vcpus via broadcasting. And there only
>>>>> one vcpu is waken up via tasklet with current logic. That's the
>>>>> reason why I want to wakeup all vcpus on one callback. Just change
>>>>> X86EMUL_RETRY to OK cannot solve the problem. still need the logic I
>>>>> mentioned above.
>>>> 
>>>> Ok, wait a sec, I will sort out a patch for you to try...
>>> Thanks. Actually, I have patch on hand and testing it now. But it's
>>> ok if you can provide a more better solution.
>> 
>> See how you like it compared with the attached patch. Attached doesn't
>> really make the code any more complicated, which is nice. However it
>> is not tested, at all. ;)
> 
> And here's a version which actually net *reduces* the code size.
> 
>  -- Keir
> 
>>  -- Keir
>> 
>>> Best regards,
>>> Yang
>>> 
>>> 
>> 
>