Re: [RFC PATCH 0/3] generic hypercall support

Avi Kivity
2009-05-07T19:27:49Z

Chris Wright wrote:
> * Gregory Haskins (ghaskins@novell.com) wrote:
>
>> Chris Wright wrote:
>>
>>> * Avi Kivity (avi@redhat.com) wrote:
>>>
>>>> Gregory Haskins wrote:
>>>>
>>>>> Cool, I will code this up and submit it. While Im at it, Ill run it
>>>>> through the "nullio" ringer, too. ;) It would be cool to see the
>>>>> pv-mmio hit that 2.07us number. I can't think of any reason why this
>>>>> will not be the case.
>>>>>
>>>>>
>>>> Don't - it's broken. It will also catch device assignment mmio and
>>>> hypercall them.
>>>>
>>> Not necessarily. It just needs to be creative w/ IO_COND
>>>
>> Hi Chris,
>> Could you elaborate? How would you know which pages to hypercall and
>> which to let PF?
>>
>
> Was just thinking of some ugly mangling of the addr (I'm not entirely
> sure what would work best).
>

I think we just past the "too complicated" threshold.

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.