Re: [Qemu-devel] [PATCH RFC 3/5] softmmu: add a tlb_vaddr_to_host_fill function

[Peter Maydell]

On 2 June 2015 at 21:58, Richard Henderson <address@hidden> wrote:
> On 06/02/2015 01:10 PM, Aurelien Jarno wrote:
>> It looks like we have to go through the MMIO functions to get the
>> TLB_NOTDIRTY bit cleaned correctly. This is something we don't want for
>> probe_write, so we definitely want two different functions.
>
> I think that's why target-arm does it's somewhat convoluted loop in which it
> stores one byte to the page and then tries again to use tlb_vaddr_to_host.

Also if we take a fault we must do so with the fault address set
to the exact address passed in by the guest in the register,
even if that isn't the first (QEMU) page in the region being cleared.
So we must test that exact byte first.

-- PMM