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

[Fedorov Sergey]

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 <address@hidden> 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 <address@hidden>
> 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 <address@hidden>
>
> thanks
> -- PMM