[PATCH 6/6] ARM: virt: hide CONFIG_ARM_VIRT_EXT from user

Christopher Covington cov at codeaurora.org
Fri Jan 11 12:22:20 EST 2013


On 01/11/2013 11:43 AM, Will Deacon wrote:
> On Fri, Jan 11, 2013 at 03:42:40PM +0000, Christopher Covington wrote:
>> Hi Will,
> 
> Hello,
> 
>> On 01/11/2013 10:34 AM, Will Deacon wrote:
>>> ARM_VIRT_EXT is a property of CPU_V7, but does not adversely affect
>>> other CPUs that can be built into the same kernel image (i.e. ARMv6+).
>>>
>>> This patch defaults ARM_VIRT_EXT to y if CPU_V7, allowing hypervisors
>>> such as KVM to make better use of the option and being able to rely
>>> on hyp-mode boot support.
>>
>> [...]
>>
>>> @@ -640,11 +641,6 @@ config ARM_VIRT_EXT
>>>  	  use of this feature.  Refer to Documentation/arm/Booting for
>>>  	  details.
>>>  
>>> -	  It is safe to enable this option even if the kernel may not be
>>> -	  booted in HYP mode, may not have support for the
>>> -	  virtualization extensions, or may be booted with a
>>> -	  non-compliant bootloader.
>>
>> Why take this out?
> 
> I just removed that last paragraph because it's not user-selectable anymore,
> so this comment about enabling the option is redundant. I could remove all
> of the help text, but we have it for some other options that are selected
> automatically and it has a pointer to some documentation too.

It's not a big deal, but that paragraph helped me understand the (lack of)
ramifications for v7 CPU's without the virtualization extensions, and I figure
it might still be helpful for others as well.

Christopher

-- 
Employee of Qualcomm Innovation Center, Inc.
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