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

[Richard Henderson]

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.

If the page isn't in the tlb, we perform a complete store and thus both pull
the page into the tlb as well as mark it dirty.  Thus if the page still isn't
present for the second vaddr_to_host, it really is I/O, or is being watched by
the debugger, or something equally unlikely.


r~