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From: cov@codeaurora.org (Christopher Covington)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 6/6] ARM: virt: hide CONFIG_ARM_VIRT_EXT from user
Date: Fri, 11 Jan 2013 12:22:20 -0500	[thread overview]
Message-ID: <50F04A4C.6020302@codeaurora.org> (raw)
In-Reply-To: <20130111164330.GA12464@mudshark.cambridge.arm.com>

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.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by
the Linux Foundation

      reply	other threads:[~2013-01-11 17:22 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-11 15:34 [PATCH 0/6] Random collection of hyp-boot fixes and updates Will Deacon
2013-01-11 15:34 ` [PATCH 1/6] ARM: virt: Avoid bx instruction for compatibility with <=ARMv4 Will Deacon
2013-01-11 15:34 ` [PATCH 2/6] ARM: virt: boot secondary CPUs through the right entry point Will Deacon
2013-01-11 15:34 ` [PATCH 3/6] ARM: virt: simplify __hyp_stub_install epilog Will Deacon
2013-01-11 15:34 ` [PATCH 4/6] ARM: virt: avoid clobbering lr when forcing svc mode Will Deacon
2013-01-11 15:34 ` [PATCH 5/6] ARM: virt: use PSR_N_BIT for detecting boot CPU mode mismatch Will Deacon
2013-01-11 15:34 ` [PATCH 6/6] ARM: virt: hide CONFIG_ARM_VIRT_EXT from user Will Deacon
2013-01-11 15:42   ` Christopher Covington
2013-01-11 16:43     ` Will Deacon
2013-01-11 17:22       ` Christopher Covington [this message]

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