Hi Jan:

          Thanks for your review.


On 2017年05月30日 23:42, Jan Beulich wrote:
>>>> On 30.05.17 at 17:36, <wei.liu2@citrix.com> wrote:
>> On Thu, May 18, 2017 at 01:34:31AM -0400, Lan Tianyu wrote:
>>> --- a/xen/common/Kconfig
>>> +++ b/xen/common/Kconfig
>>> @@ -73,6 +73,17 @@ config TMEM
>>>  
>>>  	  If unsure, say Y.
>>>  
>>> +config VIOMMU
>>> +	def_bool y
>>> +	prompt "Xen vIOMMU Support" if EXPERT = "y"
>>> +	depends on X86
>>> +	---help---
>>> +	 Virtual IOMMU provides interrupt remapping function for guest and
>>> +	 it allows guest to boot up more than 255 vcpus which requires interrupt
>>> +	 remapping function.
>>> +
>>> +	  If unsure, say Y.
>> Indentation. And this should be disabled by default.
> It's actually a question whether in our current scheme a Kconfig
> option is appropriate here in the first place. I'd rather see this be
> an always built feature which needs enabling on the command line
> for the time being.

          In the RFC V1, we made vIOMMU always built-in feature. But ARM
or other arches doesn't have vIOMMU support.

Julien suggested to introduce a new Kconfig and only built vIOMMU on
x86. Both two ways won't affect vIOMMU function.

https://www.mail-archive.com/xen-devel@lists.xen.org/msg101421.html

Jan & Julien, we need to make a choice here.

-- 
Best regards
Tianyu Lan