Re: [Qemu-devel] [PATCH] target-arm: fix TTBCR write masking

[Fedorov Sergey <s.fedorov@samsung.com>]

This patch is a prerequisite for the following up TrustZone support patches.

Thanks.

Best regards,
Sergey Fedorov

On 12/10/2013 12:57 PM, Peter Maydell wrote:
> On 10 December 2013 06:41, Sergey Fedorov <s.fedorov@samsung.com> wrote:
>> Current implementation is not accurate according to ARMv7-AR reference
>> manual. See "B4.1.153 TTBCR, Translation Table Base Control Register,
>> VMSA | TTBCR format when using the Long-descriptor translation table
>> format". When LPAE feature is supported, EAE, bit[31] selects
>> translation descriptor format and, therefore, TTBCR format.
>>
>> Signed-off-by: Sergey Fedorov <s.fedorov@samsung.com>
> Yeah, when I wrote that I was relying on the fact that all the
> valid bits in a short-format descriptor are also valid in the
> long-format mask, so correct guest software won't care (the
> other bits are UNK/SBZP). However the implementation side
> of UNK/SBZP requires us to treat the bits as RAZ/WI, so this
> patch is correct.
>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
>
> thanks
> -- PMM
>