[U-Boot] [RFC PATCH 0/6] ARMv7: Add HYP mode switching support

[Andre Przywara]

On 04/26/2013 03:42 PM, Peter Maydell wrote:
> On 26 April 2013 14:24, Andre Przywara <andre.przywara at linaro.org> wrote:
>> On 04/26/2013 03:18 PM, Peter Maydell wrote:
>>> The obvious question here is "why do we need a new command?".
>>> The kernel booting specification says "boot the kernel in
>>> Hyp mode" so we should just always do that for booting Linux,
>>> surely?
>
>> Because it avoids regressions. I kind of feel uneasy to do a lot of
>> tinkering with secure state and the GIC unconditionally, especially if
>> enabled on many boards with virt-capable CPUs.
>
> There aren't exactly very many of those out there, so if we
> default to "boot in HYP mode" then (a) KVM will just work
> out of the box and (b) people doing u-boot ports to their
> board will find any issues and be able to submit fixes.
> If we don't turn it on by default then we'll end up stuck
> in a world where KVM doesn't work on half the virt capable
> boards out there.

OK, that's a point. I changed the code already and will include it in 
the next revision.

Thanks,
Andre.

>
> I have no objection to a "turn this off" escape hatch if
> you think it's useful.
>
> -- PMM
>